TY - JOUR A1 - Wiegmann, Matti A1 - Kersten, Jens A1 - Senaratne, Hansi A1 - Potthast, Martin A1 - Klan, Friederike A1 - Stein, Benno T1 - Opportunities and risks of disaster data from social media: a systematic review of incident information JF - Natural Hazards and Earth System Sciences N2 - Compiling and disseminating information about incidents and disasters are key to disaster management and relief. But due to inherent limitations of the acquisition process, the required information is often incomplete or missing altogether. To fill these gaps, citizen observations spread through social media are widely considered to be a promising source of relevant information, and many studies propose new methods to tap this resource. Yet, the overarching question of whether and under which circumstances social media can supply relevant information (both qualitatively and quantitatively) still remains unanswered. To shed some light on this question, we review 37 disaster and incident databases covering 27 incident types, compile a unified overview of the contained data and their collection processes, and identify the missing or incomplete information. The resulting data collection reveals six major use cases for social media analysis in incident data collection: (1) impact assessment and verification of model predictions, (2) narrative generation, (3) recruiting citizen volunteers, (4) supporting weakly institutionalized areas, (5) narrowing surveillance areas, and (6) reporting triggers for periodical surveillance. Furthermore, we discuss the benefits and shortcomings of using social media data for closing information gaps related to incidents and disasters. KW - Katastrophe KW - Social Media KW - Datenbank KW - Information KW - Katastrophenmanagement KW - Soziale Medien KW - Datensammlung Y1 - 2021 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:gbv:wim2-20210804-44634 UR - https://nhess.copernicus.org/articles/21/1431/2021/nhess-21-1431-2021.html VL - 2021 IS - Volume 21, Issue 5 SP - 1431 EP - 1444 PB - European Geophysical Society CY - Katlenburg-Lindau ER - TY - JOUR A1 - Wenzel, Mirjam T1 - Das partikulare Gedächtnis jüdischer Museen N2 - Bauhaus-Gastprofessorin Mirjam Wenzel referierte am 30. Juni 2021 im Audimax der Bauhaus-Universität Weimar zur Entstehungsgeschichte und Konzeption Jüdischer Museen. Dabei ging sie darauf ein, inwiefern diese Museen besonders relevant für aktuelle gesellschaftliche und politische Fragestellungen sind. Prof. Wenzels zweiter öffentlicher Vortrag an der Bauhaus-Universität Weimar skizzierte die Potentiale von Kultureinrichtungen in Zeiten gesellschaftspolitischer Veränderungen im Allgemeinen und die Bedeutung Jüdischer Museen angesichts verbaler und tätlicher Gewalt gegen Jüdinnen und Juden im Besonderen. T3 - Neue Bauhausvorträge - 7 KW - Gedächtnis Y1 - 2021 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:gbv:wim2-20211129-45355 UR - https://www.uni-weimar.de/de/universitaet/profil/mensch-macht-moderne/juedische-museen/ ER - TY - THES A1 - Weißker, Tim T1 - Group Navigation in Multi-User Virtual Reality N2 - Multi-user virtual reality systems enable collocated as well as distributed users to perform collaborative activities in immersive virtual environments. A common activity in this context is to move from one location to the next as a group to explore the environment together. The simplest solution to realize these multi-user navigation processes is to provide each participant with a technique for individual navigation. However, this approach entails some potentially undesirable consequences such as the execution of a similar navigation sequence by each participant, a regular need for coordination within the group, and, related to this, the risk of losing each other during the navigation process. To overcome these issues, this thesis performs research on group navigation techniques that move group members together through a virtual environment. The presented work was guided by four overarching research questions that address the quality requirements for group navigation techniques, the differences between collocated and distributed settings, the scalability of group navigation, and the suitability of individual and group navigation for various scenarios. This thesis approaches these questions by introducing a general conceptual framework as well as the specification of central requirements for the design of group navigation techniques. The design, implementation, and evaluation of corresponding group navigation techniques demonstrate the applicability of the proposed framework. As a first step, this thesis presents ideas for the extension of the short-range teleportation metaphor, also termed jumping, for multiple users. It derives general quality requirements for the comprehensibility of the group jumping process and introduces a corresponding technique for two collocated users. The results of two user studies indicate that sickness symptoms are not affected by user roles during group jumping and confirm improved planning accuracy for the navigator, increased spatial awareness for the passenger, and reduced cognitive load for both user roles. Next, this thesis explores the design space of group navigation techniques in distributed virtual environments. It presents a conceptual framework to systematize the design decisions for group navigation techniques based on Tuckman's model of small-group development and introduces the idea of virtual formation adjustments as part of the navigation process. A quantitative user study demonstrates that the corresponding extension of Multi-Ray Jumping for distributed dyads leads to more efficient travel sequences and reduced workload. The results of a qualitative expert review confirm these findings and provide further insights regarding the complementarity of individual and group navigation in distributed virtual environments. Then, this thesis investigates the navigation of larger groups of distributed users in the context of guided museum tours and establishes three central requirements for (scalable) group navigation techniques. These should foster the awareness of ongoing navigation activities as well as facilitate the predictability of their consequences for all group members (Comprehensibility), assist the group with avoiding collisions in the virtual environment (Obstacle Avoidance), and support placing the group in a meaningful spatial formation for the joint observation and discussion of objects (View Optimization). The work suggests a new technique to address these requirements and reports on its evaluation in an initial usability study with groups of five to ten (partially simulated) users. The results indicate easy learnability for navigators and high comprehensibility for passengers. Moreover, they also provide valuable insights for the development of group navigation techniques for even larger groups. Finally, this thesis embeds the previous contributions in a comprehensive literature overview and emphasizes the need to study larger, more heterogeneous, and more diverse group compositions including the related social factors that affect group dynamics. In summary, the four major research contributions of this thesis are as follows: - the framing of group navigation as a specific instance of Tuckman's model of small-group development - the derivation of central requirements for effective group navigation techniques beyond common quality factors known from single-user navigation - the introduction of virtual formation adjustments during group navigation and their integration into concrete group navigation techniques - evidence that appropriate pre-travel information and virtual formation adjustments lead to more efficient travel sequences for groups and lower workloads for both navigators and passengers Overall, the research of this thesis confirms that group navigation techniques are a valuable addition to the portfolio of interaction techniques in multi-user virtual reality systems. The conceptual framework, the derived quality requirements, and the development of novel group navigation techniques provide effective guidance for application developers and inform future research in this area. N2 - Multi-User-Virtual-Reality-Systeme ermöglichen es lokalen und räumlich getrennten Benutzer*innen, kollaborative Aktivitäten in einer immersiven virtuellen Umgebung auszuüben. Eine grundlegende Aufgabe in diesem Zusammenhang ist die Navigation von einem Ort zum nächsten als Gruppe, um die Umgebung gemeinsam zu erkunden. Die einfachste Lösung zur Realisierung dieser Mehrbenutzer*innen-Navigationsprozesse besteht darin, jedem*jeder Teilnehmer*in eine Technik zur individuellen Navigation zur Verfügung zu stellen. Dieser Ansatz führt jedoch zu einigen potenziell unerwünschten Begleiterscheinungen, wie zum Beispiel der Ausführung einer ähnlichen Navigationssequenz durch jede*n Teilnehmer*in, einem regelmäßigen Koordinationsbedarf innerhalb der Gruppe und damit verbunden der Gefahr, sich während des Navigationsprozesses zu verlieren. Zur Überwindung dieser Problematiken erforscht die vorliegende Arbeit Gruppennavigationstechniken, die alle Gruppenmitglieder gemeinsam durch eine virtuelle Umgebung bewegen. Die vorgestellten Beiträge wurden von vier übergreifenden Forschungsfragen geleitet, welche sich mit Qualitätsanforderungen an Gruppennavigationstechniken, den Unterschieden zwischen lokaler und räumlich getrennter Teilnahme, der Skalierbarkeit von Gruppennavigation und der Eignung von Einzel- und Gruppennavigationstechniken für verschiedene Szenarien befassen. Die vorliegende Arbeit nähert sich diesen Fragen durch die Einführung eines allgemeinen konzeptionellen Frameworks sowie die Spezifikation zentraler Anforderungen an den Entwurf von Gruppennavigationstechniken. Die Entwicklung, Implementierung und Evaluation entsprechender Gruppennavigationstechniken demonstrieren die Anwendbarkeit des vorgeschlagenen Frameworks. In einem ersten Schritt stellt diese Arbeit Ideen zur Erweiterung der Teleportationsmetapher über kurze Distanzen, auch Jumping genannt, für mehrere Benutzer*innen vor. Sie leitet allgemeine Qualitätsanforderungen zur Verständlichkeit des Gruppen-Jumpings ab und präsentiert eine entsprechende Technik für zwei lokale Benutzer*innen. Die Ergebnisse zweier Benutzungsstudien zeigen keine Einflüsse des aktiven oder passiven Jumpings auf Symptome der Simulatorkrankheit und bestätigen eine erhöhte Planungsgenauigkeit für den*die Navigator*in, ein verbessertes räumliches Verständnis für den*die Passagier*in und eine reduzierte kognitive Belastung für beide Rollen. Danach untersucht diese Arbeit den Gestaltungsraum von Gruppennavigationstechniken in verteilten virtuellen Umgebungen. Basierend auf Tuckmans Modell der Kleingruppenentwicklung stellt sie ein konzeptionelles Framework zur Systematisierung der Designentscheidungen für Gruppennavigationstechniken vor und führt die Idee der virtuellen Formationsanpassungen als Teil des Navigationsprozesses ein. Eine quantitative Benutzungsstudie zeigt, dass eine entsprechende Erweiterung des Multi-Ray Jumpings für räumlich getrennte Dyaden zu effizienteren Navigationsabläufen und geringeren wahrgenommenen Arbeitslasten führt. Die Ergebnisse eines qualitativen Expert-Reviews bestätigen diese Erkenntnisse und liefern weitere Einsichten bezüglich der Komplementarität von Einzel- und Gruppennavigation in verteilten virtuellen Umgebungen. Anschließend untersucht diese Arbeit die Navigation größerer Gruppen räumlich getrennter Benutzer*innen im Kontext von Museumsführungen und stellt drei zentrale Anforderungen für (skalierbare) Gruppennavigationstechniken auf. Diese sollen das Bewusstsein für laufende Navigationsaktivitäten fördern sowie die Vorhersehbarkeit ihrer Konsequenzen für alle Gruppenmitglieder erleichtern (Verständlichkeit), der Gruppe bei der Vermeidung von Kollisionen in der virtuellen Umgebung assistieren (Hindernisvermeidung) und die Platzierung der Gruppe in einer sinnvollen räumlichen Formation für die gemeinsame Betrachtung und Diskussion von Objekten unterstützen (Blickoptimierung). Die Arbeit stellt eine neue Technik zur Adressierung dieser Anforderungen vor, welche in einer initialen Usability-Studie mit Gruppen von fünf bis zehn (teilweise simulierten) Benutzer*innen evaluiert wurde. Die Ergebnisse zeigen eine einfache Erlernbarkeit für den*die Navigator*in und eine hohe Verständlichkeit für Passagier*innen. Darüber hinaus liefern sie wertvolle Erkenntnisse zur Entwicklung von Gruppennavigationstechniken für noch größere Gruppenstärken. Abschließend bettet diese Arbeit die bisherigen Beiträge in einen umfassenden Literaturüberblick ein und betont den Bedarf zukünftiger Forschungsarbeiten zu größeren, heterogeneren und diverseren Gruppenkompositionen. Dies beinhaltet ebenfalls die Betrachtung der damit verbundenen sozialen Faktoren sowie deren Einfluss auf die Gruppendynamik. Zusammengefasst lauten die vier wichtigsten Forschungsbeiträge dieser Arbeit wie folgt: - die Einordnung von Gruppennavigationsprozessen als spezifische Instanz von Tuckmans Modell der Kleingruppenentwicklung - die Ableitung zentraler Anforderungen an effektive Gruppennavigationstechniken zusätzlich zu aus Einzelnavigationskontexten bekannten Qualitätsfaktoren - die Einführung von virtuellen Formationsanpassungen als Teil der Gruppennavigation und deren Integration in konkrete Gruppennavigationstechniken - Nachweise, dass geeignet gewählte Vorschaumechanismen sowie virtuelle Formationsanpassungen zu effizienteren Navigationssequenzen für die Gruppe und geringeren wahrgenommenen Arbeitslasten für Navigator*innen und Passagier*innen führen Insgesamt bestätigen die Ergebnisse dieser Arbeit, dass Gruppennavigationstechniken eine wertvolle Ergänzung zum Portfolio der Interaktionstechniken in Multi-User-Virtual-Reality-Systemen sind. Das konzeptionelle Framework, die abgeleiteten Qualitätsanforderungen und die Entwicklung entsprechender Gruppennavigationstechniken bilden eine relevante Wissensbasis für Anwendungsentwickler*innen und informieren zukünftige Forschung in diesem Gebiet. KW - Virtuelle Realität KW - Mensch-Maschine-Kommunikation KW - Multi-User Virtual Reality KW - Group Navigation KW - Collaborative Virtual Environments KW - Human-Computer Interaction Y1 - 2021 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:gbv:wim2-20211124-45305 ER - TY - RPRT A1 - Vollmer, Lisa A1 - Calbet i Elias, Laura A1 - Raab, Susanna A1 - Aya, Kleine A1 - Zanders, Theresa T1 - Teilhabe und Gemeinwohl – ihre Krisen im deutschen Wohlfahrtsregime. Begriffsdefinitionen und aktuelle Verortungen N2 - Im ersten Working Paper des Forschungsprojekts „Städtische Ko-Produktion von Teilhabe und Gemeinwohl. Aushandlungsprozesse zwischen zivilgesellschaft lichen Akteuren und kommunalen Verwaltungen“ möchten wir die von uns verwendeten zentralen Begrifflichkeiten definieren sowie einige Grundannahmen erläutern. Im Anschluss an Definitionen der Begriff e Wohlfahrtsregime, Teilhabe, Gemeinwohl, Governance, Zivilgesellschaft und soziale Bewegungen erfolgt eine Analyse der heutigen Krise von Teilhabe, die wir als Ausgangspunkt zur Untersuchung unserer Fallstudien definieren. Das Working Paper dient sowohl der internen Selbstverständigung im Projekt als auch dem Austausch mit anderen Forschenden in der Förderlinie „Teilhabe und Gemeinwohl“ des Bundesministeriums für Bildung und Forschung (BMBF) sowie darüber hinaus mit Projekten, die sich ähnlichen Themen widmen. T3 - KoopWohl - Working Paper - 1 KW - Gemeinwohl KW - Teilhabe KW - Zivilgesellschaft KW - soziale Bewegung KW - Ko-Produktion Y1 - 2021 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:gbv:wim2-20210519-44320 ER - TY - JOUR A1 - Vollmer, Lisa T1 - In die Gänge gekommen: Kooperation von Zivilgesellschaft und Stadtpolitik. Rezension zu Michael Ziehl (2020): Koproduktion urbaner Resilienz. Das Gängeviertel in Hamburg als Reallabor für eine zukunftsfähige Stadtentwicklung mittels Kooperation von Zivilgesellschaft, Politik und Verwaltung. JF - sub\urban. Zeitschrift für Kritische Stadtforschung N2 - Schlagworte wir Kooperation, Koproduktion und Kollaboration sind in Planungswissenschaften und Architektur schwer in Mode. Selten wird allerdings dargelegt, was diese Art(en) der Zusammenarbeit zwischen zivilgesellschaftlichen Akteuren auf der einen Seite und staatlichen Akteuren aus Politik und Verwaltung auf der anderen Seite von gewöhnlichen Formen der Partizipation und Bürger_innenbeteiligung unterscheidet. Anders im Buch von Michael Ziehl: Ihm gelingt es, anhand eines Fallbeispiels die intensive Zusammenarbeit zwischen Aktivist_innen rund ums Hamburger Gängeviertel und verschiedenen städtischen Institutionen detailliert nachzuzeichnen und damit den qualitativen Unterschied zwischen Kooperation und Beteiligung nachvollziehbar zu machen. KW - Hamburg KW - Stadtentwicklung KW - Hamburg KW - Kooperation KW - Zivilgesellschaft KW - OA-Publikationsfonds2021 Y1 - 2021 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:gbv:wim2-20210806-44798 UR - https://zeitschrift-suburban.de/sys/index.php/suburban/article/view/681 VL - 2021 IS - Band 9, Heft 1/2 SP - 241 EP - 247 PB - sub\urban e. V. CY - Berlin ER - TY - JOUR A1 - Vakkari, Pertti A1 - Völske, Michael A1 - Potthast, Martin A1 - Hagen, Matthias A1 - Stein, Benno T1 - Predicting essay quality from search and writing behavior JF - Journal of Association for Information Science and Technology N2 - Few studies have investigated how search behavior affects complex writing tasks. We analyze a dataset of 150 long essays whose authors searched the ClueWeb09 corpus for source material, while all querying, clicking, and writing activity was meticulously recorded. We model the effect of search and writing behavior on essay quality using path analysis. Since the boil-down and build-up writing strategies identified in previous research have been found to affect search behavior, we model each writing strategy separately. Our analysis shows that the search process contributes significantly to essay quality through both direct and mediated effects, while the author's writing strategy moderates this relationship. Our models explain 25–35% of the variation in essay quality through rather simple search and writing process characteristics alone, a fact that has implications on how search engines could personalize result pages for writing tasks. Authors' writing strategies and associated searching patterns differ, producing differences in essay quality. In a nutshell: essay quality improves if search and writing strategies harmonize—build-up writers benefit from focused, in-depth querying, while boil-down writers fare better with a broader and shallower querying strategy. KW - Information Retrieval KW - Textproduktion KW - Suchverfahren KW - Aufsatz KW - Suchverhalten KW - Pfadanalyse KW - Suchmaschine Y1 - 2021 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:gbv:wim2-20210804-44692 UR - https://asistdl.onlinelibrary.wiley.com/doi/10.1002/asi.24451 VL - 2021 IS - volume 72, issue 7 SP - 839 EP - 852 PB - Wiley CY - Hoboken, NJ ER - TY - JOUR A1 - Staubach, Patrick A1 - Machacek, Jan A1 - Skowronek, Josefine A1 - Wichtmann, Torsten T1 - Vibratory pile driving in water-saturated sand: Back-analysis of model tests using a hydro-mechanically coupled CEL method JF - Soils and Foundations N2 - The development of a hydro-mechanically coupled Coupled-Eulerian–Lagrangian (CEL) method and its application to the back-analysisof vibratory pile driving model tests in water-saturated sand is presented. The predicted pile penetration using this approachis in good agreement with the results of the model tests as well as with fully Lagrangian simulations. In terms of pore water pressure, however, the results of the CEL simulation show a slightly worse accordance with the model tests compared to the Lagrangian simulation. Some shortcomings of the hydro-mechanically coupled CEL method in case of frictional contact problems and pore fluids with high bulk modulus are discussed. Lastly, the CEL method is applied to the simulation of vibratory driving of open-profile piles under partially drained conditions to study installation-induced changes in the soil state. It is concluded that the proposed method is capable of realistically reproducing the most important mechanisms in the soil during the driving process despite its addressed shortcomings. KW - Plastische Deformation KW - Vibratory pile driving KW - Coupled-Eulerian–Lagrangian KW - Hydro-mechanically coupled KW - Hypoplasticity KW - Relative acceleration KW - Large deformation KW - Deformationsverhalten KW - Plastizität KW - OA-Publikationsfonds2020 Y1 - 2020 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:gbv:wim2-20210203-43571 UR - https://www.sciencedirect.com/science/article/pii/S0038080620337586?via%3Dihub VL - 2021 IS - Volume 61, Issue 1 SP - 144 EP - 159 PB - Elsevier, Science Direct CY - Amsterdam ER - TY - THES A1 - Stang, René T1 - Methode zur Ökoeffizienzbewertung wärmetechnischer Anlagen in Gebäuden N2 - Die vorliegende Arbeit richtet sich an Ingenieur*innen und Wissenschaftler*innen der technischen Gebäudeausrüstung. Sie greift einen sich abzeichnenden Änderungsbedarf in der Umwelt- und Nachhaltigkeitsbewertung von Gebäuden und wärmetechnischen Anlagen auf. Der aktuell genutzte nicht erneuerbare Primärenergiebedarf wird insbesondere hinsichtlich künftiger politischer Klima- und Umweltschutzziele als alleinige Bewertungsgröße nicht ausreichend sein. Die mit dieser Arbeit vorgestellte Ökoeffizienzbewertungsmethode kann als geeignetes Instrument zur Lösung der Probleme beitragen. Sie ermöglicht systematische, ganzheitliche Bewertungen und reproduzierbare Vergleiche wärmetechnischer Anlagen bezüglich ihrer ökologischen und ökonomischen Nachhaltigkeit. Die wesentlichsten Neuentwicklungen sind die spezifische Umweltleistung, in Erweiterung zum genutzten Primärenergiefaktor, und der Ökoeffizienzindikator UWI. KW - Energiewirtschaft KW - Nachhaltigkeit KW - Primärenergie KW - erneuerbare Energie KW - Wärmebedarf KW - Nachhaltigkeitsbewertung KW - Ökobilanz KW - Ökoeffizienz KW - Primärenergiefaktor KW - Umweltleistung Y1 - 2021 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:gbv:wim2-20211119-45280 SN - 978-3-18-300623-6 (print) PB - VDI Verlag CY - Düsseldorf ER - TY - THES A1 - Spröte, Daniel T1 - Immobilienportfoliomanagement öffentlicher musealer Schlösserverwaltungen - Daten zur Investitionssteuerung N2 - Die Arbeit leistet einen wissenschaftlichen Beitrag zur Erforschung der Einsatzmöglichkeiten eines Immobilienportfoliomanagements für öffentliche museale Schlösserverwaltungen in Deutschland. Insbesondere wird ein für deren Organisation spezifisches Modell zur Investitionssteuerung herausgearbeitet und dessen Anwendbarkeit in der Praxis mit Experten diskutiert. KW - Unbewegliche Sache KW - Portfoliomanagement KW - Museum KW - Schloss KW - Investition Y1 - 2021 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:gbv:wim2-20210510-44260 ER - TY - INPR A1 - Sheikh Khozani, Zohreh A1 - Kumbhakar, Manotosh T1 - Discussion of “Estimation of one-dimensional velocity distribution by measuring velocity at two points” by Yeganeh and Heidari (2020) N2 - The concept of information entropy together with the principle of maximum entropy to open channel flow is essentially based on some physical consideration of the problem under consideration. This paper is a discussion on Yeganeh and Heidari (2020)’s paper, who proposed a new approach for measuring vertical distribution of streamwise velocity in open channels. The discussers argue that their approach is conceptually incorrect and thus leads to a physically unrealistic situation. In addition, the discussers found some wrong mathematical expressions (which are assumed to be typos) written in the paper, and also point out that the authors did not cite some of the original papers on the topic. KW - Geschwindigkeit KW - Entropie Y1 - 2021 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:gbv:wim2-20210216-43663 N1 - This is the pre-peer reviewed version of the following article: https://www.sciencedirect.com/science/article/pii/S0955598621000017 ; https://doi.org/10.1016/j.flowmeasinst.2021.101886 ER - TY - THES A1 - Shamskooshki, Hanieh T1 - Perception of Socio-Spatial Segregation: The Interaction of Physical and Social Urban Space-Study case of Tehran Neighborhoods N2 - “How to understand the interaction between urban space and social processes” is a significant question in urban studies. To answer that, the city needs to be recognized as both a physical and a social entity and urban theory and practice need to connect these (Hillier 2007). The present research aims to re-examine the complex correlation between spatial and social inequality manifestations in the city of Tehran regarding the concept of segregation. It observes the causes and consequences of segregation in Tehran and provides an insight into both concepts of socio-spatial segregation and neighborhood effects and creates a link between them. First, I argue when, where, and for whom spatial locations affect the chances of social networks in Tehran. Then, I discuss how neighborhood effects can emerge via social network mechanisms and thus affect the perceptions of residents in the neighborhoods. KW - Soziales Netzwerk KW - Socio-spatial Segregation KW - Urban Space KW - Neighborhood Effects KW - Social Networks Y1 - 2021 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:gbv:wim2-20210802-44666 ER - TY - JOUR A1 - Seichter, Cosima Zita A1 - Neßler, Miriam A1 - Knopf, Paul T1 - Der Refugee District in Belgrad. Ein Raum der Nicht-Bewegung zwischen neoliberaler Stadtentwicklung, serbischem Migrationsmanagement und EU-Grenzregime JF - sub\urban. Zeitschrift für Kritische Stadtforschung N2 - Durch internationale Fluchtbewegungen über die sogenannte Balkanroute bildete sich in Serbiens Hauptstadt Belgrad in den letzten Jahren ein sogenannter Refugee District heraus. Im Kontext von Migration und Flucht werden dabei zahlreiche Spannungsfelder auf unterschiedlichen räumlichen und politischen Ebenen sichtbar. Für Flüchtende kreieren diese eine Situation, die von Stillstand, Ausweglosigkeit, Kontrolle, Gefahr und Verdrängung geprägt ist. Allerdings führen die Vielschichtigkeit und die Diversität unterschiedlicher Akteur*innen, die bezüglich der Situation von Flüchtenden auf der Balkanroute wirkmächtig sind, auch zu Nischen, Widerständigkeiten und der Möglichkeit (neuer) Allianzen. Auf diese Weise entsteht eine kollektive Praktik der Nicht-Bewegung im Widerstand gegen die Unterdrückung und für globale Bewegungsfreiheit. KW - Belgrad KW - Europäische Union KW - Flüchtling KW - Flüchtlingspolitik KW - Balkanroute KW - Grenzregime KW - refugee district KW - OA-Publikationsfonds2021 Y1 - 2021 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:gbv:wim2-20210805-44776 UR - https://zeitschrift-suburban.de/sys/index.php/suburban/article/view/622 VL - 2021 IS - Band 9, Heft 1/2 SP - 225 EP - 234 PB - sub\urban e.V. CY - Berlin ER - TY - JOUR A1 - Schwerzmann, Katia T1 - Abolish! Against the Use of Risk Assessment Algorithms at Sentencing in the US Criminal Justice System JF - Philosophy & Technology N2 - In this article, I show why it is necessary to abolish the use of predictive algorithms in the US criminal justice system at sentencing. After presenting the functioning of these algorithms in their context of emergence, I offer three arguments to demonstrate why their abolition is imperative. First, I show that sentencing based on predictive algorithms induces a process of rewriting the temporality of the judged individual, flattening their life into a present inescapably doomed by its past. Second, I demonstrate that recursive processes, comprising predictive algorithms and the decisions based on their predictions, systematically suppress outliers and progressively transform reality to match predictions. In my third and final argument, I show that decisions made on the basis of predictive algorithms actively perform a biopolitical understanding of justice as management and modulation of risks. In such a framework, justice becomes a means to maintain a perverse social homeostasis that systematically exposes disenfranchised Black and Brown populations to risk. KW - Biopolitik KW - Soziale Gerechtigkeit KW - Algorithmus KW - predictive algorithms KW - cybernetics KW - criminal justice KW - social justice KW - biopolitics Y1 - 2021 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:gbv:wim2-20211207-45417 UR - https://link.springer.com/article/10.1007/s13347-021-00491-2 VL - 2021 SP - 1 EP - 22 ER - TY - GEN A1 - Schuster, Lara T1 - Die Haltungen des Architekten Luigi Snozzi. Untersucht am Beispiel des Projektes Monte Carasso N2 - Welche Haltung spricht aus den Werken von Architekt*innen? Lassen sich Werte und Handlungsanweisungen von Mauern und Plänen ablesen? Luigi Snozzis Entwürfe für Monte Carasso werden in dieser Arbeit exemplarisch darauf untersucht. Sie zeugen von der Verantwortung, die jede*r Architekt*in für das Umfeld hat, in dem sie oder er baut. T3 - LUCIA Open Paper - 3 KW - Architektur Y1 - 2021 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:gbv:wim2-20210603-44386 VL - 2021 PB - Lucia Verlag CY - Weimar ER - TY - JOUR A1 - Schmitz, Tonia A1 - Kraft, Eckhard T1 - Pilot scale photobioreactor system for land-based macroalgae cultivation JF - Journal of Applied Phycology N2 - Marine macroalgae such as Ulva intestinalis have promising properties as feedstock for cosmetics and pharmaceuticals. However, since the quantity and quality of naturally grown algae vary widely, their exploitability is reduced – especially for producers in high-priced markets. Moreover, the expansion of marine or shore-based cultivation systems is unlikely in Europe, since promising sites either lie in fishing zones, recreational areas, or natural reserves. The aim was therefore to develop a closed photobioreactor system enabling full control of abiotic environmental parameters and an effective reconditioning of the cultivation medium in order to produce marine macroalgae at sites distant from the shore. To assess the feasibility and functionality of the chosen technological concept, a prototypal plant has been implemented in central Germany – a site distant from the sea. Using a newly developed, submersible LED light source, cultivation experiments with Ulva intestinalis led to growth rates of 7.72 ± 0.04 % day−1 in a cultivation cycle of 28 days. Based on the space demand of the production system, this results in fresh mass productivity of 3.0 kg m−2, respectively, of 1.1 kg m−2 per year. Also considering the ratio of biomass to energy input amounting to 2.76 g kWh−1, significant future improvements of the developed photobioreactor system should include the optimization of growth parameters, and the reduction of the system’s overall energy demand. KW - Makroalgen KW - Photobioreaktor KW - macro algae KW - photobioreactor KW - ulva intestinalis KW - LED light source Y1 - 2021 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:gbv:wim2-20211207-45401 UR - https://link.springer.com/article/10.1007/s10811-021-02617-7 VL - 2021 SP - 1 EP - 10 ER - TY - JOUR A1 - Schmidt, Albrecht A1 - Lahmer, Tom T1 - Efficient domain decomposition based reliability analysis for polymorphic uncertain material parameters JF - Proceedings in Applied Mathematics & Mechanics N2 - Realistic uncertainty description incorporating aleatoric and epistemic uncertainties can be described within the framework of polymorphic uncertainty, which is computationally demanding. Utilizing a domain decomposition approach for random field based uncertainty models the proposed level-based sampling method can reduce these computational costs significantly and shows good agreement with a standard sampling technique. While 2-level configurations tend to get unstable with decreasing sampling density 3-level setups show encouraging results for the investigated reliability analysis of a structural unit square. KW - Polymorphie KW - Stoffeigenschaft KW - Stochastik KW - polymorphe Unschärfemodellierung KW - Materialverhalten KW - hybride Werkstoffe Y1 - 2021 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:gbv:wim2-20220112-45563 UR - https://onlinelibrary.wiley.com/doi/full/10.1002/pamm.202100014 VL - 2021 IS - Volume 21, issue 1 SP - 1 EP - 4 PB - Wiley-VHC CY - Weinheim ER - TY - THES A1 - Ruhland, Grit T1 - FOLGELANDSCHAFT. Eine Untersuchung der Auswirkungen des Uranbergbaus auf die Landschaft um Gera/Ronneburg. N2 - Das Kernthema dieser Arbeit ist die Beschäftigung mit den Folgen des Uranbergbaus in dem Gebiet um die ehemalige Abbauregion der Wismut SAG/SDAG in Ronneburg (Ostthüringen). Dieses Thema wird unter historischen, sozialen, kulturanthropologischen und künstlerischen Aspekten betrachtet und in den Zusammenhang mit den weltweiten Voraussetzungen der Nuklearindustrie und Auswirkungen des Uranbergbaus und seiner Folgen gestellt. Die Arbeit legt dar, wie eine Uranbergbaufolgelandschaft entsteht und welches Wissen ist für ein angemessenes Verständnis des Phänomens wichtig ist. Es wird untersucht, ob Kunst bezüglich der Uranbergbaufolgelandschaft einen relevanten Beitrag leisten kann bzw. in welcher Form dies versucht wurde, bzw. stellte Arbeiten vor, die verwandete Themen bearbeitet haben. In Kombination dieser beiden Hauptaspekte geht die Arbeit der Frage nach, welche Faktoren die Uranbergbaufolgelandschaft prägen und ob es sinnvolle Beteiligungsfelder für künstlerisches Forschen oder Handeln gibt sowie welche Bedingungen hierfür erfüllt werdenmüssten. Die Kernthese der Arbeit ist, dass künstlerische Arbeiten im Themenfeld des Uranbergbaus unter bestimmten Bedingungen relevante Beiträge leisten können. N2 - This thesis is exploring the consequences of uranium mining in the area around the former mining region of the Wismut SAG / SDAG in Ronneburg (East Thuringia), East Germany. The topic is viewed from historical, social, cultural-anthropological and artistic aspects and placed in the context of the worldwide requirements of the nuclear industry and the effects of uranium mining and its consequences. The thesis explains how a uranium mining landscape is created and what knowledge is important for an adequate understanding of the phenomenon. It is examined whether art can make a relevant contribution in dealing with the uranium mining landscape. It discusses artworks that have dealt with related topics. In combination of these two main aspects, the thesis investigates the question which factors shape the uranium mining landscape and whether there are meaningful fields of participation for artistic research and which conditions would have to be met for this. The core thesis of the work is that artistic work in the field of uranium mining can make relevant contributions under certain conditions. It also contains field research, interviews and the description and application of a method called "random-structured landscape observation". KW - Uranbergbau KW - Nachbergbau KW - Geiger-Müller-Zählrohr KW - Kerntechnische Industrie KW - Nuclear Art KW - Environmental Art KW - Künstlerische Forschung KW - Artistic Research KW - Geigerzähler KW - Nuklearindustrie KW - Atomindustrie Y1 - 2021 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:gbv:wim2-20210906-44953 ER - TY - BOOK A1 - Roselt, Sabine A1 - Huber, Sophie A1 - Kießling, Josepha A1 - Neumeier, Lolina A1 - Bahr, Linus ED - Lell, Peter T1 - From Tradition to Television – Diverse Perspectives on Afghan Music N2 - What is Afghan music and what is its contemporary state? This question seems important to ask, considering the conflictual recent past of the country that particularly affected cultural expressions such as music. In these four articles diverse perspectives on Afghan music are explored. From traditional music of the Afghan rubab and its masters up to popular music of the Afghan-German hiphop producer “Farhot”, various insights are given into phenomena yet barely covered in academic works. This collection provides glimpses into the variety of the music of Afghanistan and the Afghan diaspora and help to shape the Western views on the music of the country into more diverse perspectives. We move further away from the bias of the majority of media representations predominantly showing the conflictual sides of Afghanistan, at the same time avoiding a limiting and narrow view on Afghanistan with solely a musical tradition located in the past. These essays go beyond and outline that apart from a rich tradition, there are present forms of musical expression. We move from “Tradition to Television” and beyond, exploring views on the future of music connected to Afghanistan. T3 - sounding heritage - 6 KW - Musik KW - Kulturerbe KW - Afghanistan KW - Musikethnologie KW - ethnomusicology KW - Afghan music KW - musical heritage Y1 - 2021 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:gbv:wim2-20210510-43682 ER - TY - THES A1 - Reshetnikova, Tatiana T1 - Transformation of the Environment: Influence of “Urban Reagents.” German and Russian Case Studies N2 - An urban regeneration manifests itself through urban objects operating as change agents. The en-tailed diverse effects on the surroundings demonstrate experimental origin - an experiment as a preplanned but unpredictable method. An understanding of influences and features of urban ob-jects requires scrutiny due to a high potential of the elements to force an alteration and reactions. This dissertation explores the transformation of the milieu and mechanisms of this transformation. KW - urban reagent KW - urban transformation KW - urban virus KW - effects of architecture KW - experiment KW - Stadtentwicklung KW - urban regeneration KW - iconic architecture KW - influence of architecture Y1 - 2021 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:gbv:wim2-20210128-43517 N1 - Dissertation and Appendix (Folder + CD) to conferral of the academic degree Doctor of Engineering (Dr.-Ing.) at the Faculty of Architecture of the Bauhaus University Weimar, submitted by Reshetnikova Tatiana Sergeevna M.Design, Diploma in “Design” Date of birth 29\11\1984 Weimar, 2020 Supervisor Prof. Dr. phil. habil. Frank Eckardt Reviewers Prof. Dr. phil. habil. Frank Eckardt Prof. Vitaly Stadnikov (PhD) Date of the disputation: 22.01.2021 ER - TY - JOUR A1 - Ren, Huilong A1 - Zhuang, Xiaoying A1 - Oterkus, Erkan A1 - Zhu, Hehua A1 - Rabczuk, Timon T1 - Nonlocal strong forms of thin plate, gradient elasticity, magneto-electro-elasticity and phase-field fracture by nonlocal operator method JF - Engineering with Computers N2 - The derivation of nonlocal strong forms for many physical problems remains cumbersome in traditional methods. In this paper, we apply the variational principle/weighted residual method based on nonlocal operator method for the derivation of nonlocal forms for elasticity, thin plate, gradient elasticity, electro-magneto-elasticity and phase-field fracture method. The nonlocal governing equations are expressed as an integral form on support and dual-support. The first example shows that the nonlocal elasticity has the same form as dual-horizon non-ordinary state-based peridynamics. The derivation is simple and general and it can convert efficiently many local physical models into their corresponding nonlocal forms. In addition, a criterion based on the instability of the nonlocal gradient is proposed for the fracture modelling in linear elasticity. Several numerical examples are presented to validate nonlocal elasticity and the nonlocal thin plate. KW - Bruchmechanik KW - Elastizität KW - Peridynamik KW - energy form KW - weak form KW - peridynamics KW - variational principle KW - explicit time integration Y1 - 2021 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:gbv:wim2-20211207-45388 UR - https://link.springer.com/article/10.1007/s00366-021-01502-8 VL - 2021 SP - 1 EP - 22 ER - TY - THES A1 - Ren, Huilong T1 - Dual-horizon peridynamics and Nonlocal operator method N2 - In the last two decades, Peridynamics (PD) attracts much attention in the field of fracture mechanics. One key feature of PD is the nonlocality, which is quite different from the ideas in conventional methods such as FEM and meshless method. However, conventional PD suffers from problems such as constant horizon, explicit algorithm, hourglass mode. In this thesis, by examining the nonlocality with scrutiny, we proposed several new concepts such as dual-horizon (DH) in PD, dual-support (DS) in smoothed particle hydrodynamics (SPH), nonlocal operators and operator energy functional. The conventional PD (SPH) is incorporated in the DH-PD (DS-SPH), which can adopt an inhomogeneous discretization and inhomogeneous support domains. The DH-PD (DS-SPH) can be viewed as some fundamental improvement on the conventional PD (SPH). Dual formulation of PD and SPH allows h-adaptivity while satisfying the conservations of linear momentum, angular momentum and energy. By developing the concept of nonlocality further, we introduced the nonlocal operator method as a generalization of DH-PD. Combined with energy functional of various physical models, the nonlocal forms based on dual-support concept are derived. In addition, the variation of the energy functional allows implicit formulation of the nonlocal theory. At last, we developed the higher order nonlocal operator method which is capable of solving higher order partial differential equations on arbitrary domain in higher dimensional space. Since the concepts are developed gradually, we described our findings chronologically. In chapter 2, we developed a DH-PD formulation that includes varying horizon sizes and solves the "ghost force" issue. The concept of dual-horizon considers the unbalanced interactions between the particles with different horizon sizes. The present formulation fulfills both the balances of linear momentum and angular momentum exactly with arbitrary particle discretization. All three peridynamic formulations, namely bond based, ordinary state based and non-ordinary state based peridynamics can be implemented within the DH-PD framework. A simple adaptive refinement procedure (h-adaptivity) is proposed reducing the computational cost. Both two- and three- dimensional examples including the Kalthoff-Winkler experiment and plate with branching cracks are tested to demonstrate the capability of the method. In chapter 3, a nonlocal operator method (NOM) based on the variational principle is proposed for the solution of waveguide problem in computational electromagnetic field. Common differential operators as well as the variational forms are defined within the context of nonlocal operators. The present nonlocal formulation allows the assembling of the tangent stiffness matrix with ease, which is necessary for the eigenvalue analysis of the waveguide problem. The present formulation is applied to solve 1D Schrodinger equation, 2D electrostatic problem and the differential electromagnetic vector wave equations based on electric fields. In chapter 4, a general nonlocal operator method is proposed which is applicable for solving partial differential equations (PDEs) of mechanical problems. The nonlocal operator can be regarded as the integral form, ``equivalent'' to the differential form in the sense of a nonlocal interaction model. The variation of a nonlocal operator plays an equivalent role as the derivatives of the shape functions in the meshless methods or those of the finite element method. Based on the variational principle, the residual and the tangent stiffness matrix can be obtained with ease. The nonlocal operator method is enhanced here also with an operator energy functional to satisfy the linear consistency of the field. A highlight of the present method is the functional derived based on the nonlocal operator can convert the construction of residual and stiffness matrix into a series of matrix multiplications using the predefined nonlocal operators. The nonlocal strong forms of different functionals can be obtained easily via the concept of support and dual-support. Several numerical examples of different types of PDEs are presented. In chapter 5, we extended the NOM to higher order scheme by using a higher order Taylor series expansion of the unknown field. Such a higher order scheme improves the original NOM in chapter 3 and chapter 4, which can only achieve one-order convergence. The higher order NOM obtains all partial derivatives with specified maximal order simultaneously without resorting to shape functions. The functional based on the nonlocal operators converts the construction of residual and stiffness matrix into a series of matrix multiplication on the nonlocal operator matrix. Several numerical examples solved by strong form or weak form are presented to show the capabilities of this method. In chapter 6, the NOM proposed as a particle-based method in chapter 3,4,5, has difficulty in imposing accurately the boundary conditions of various orders. In this paper, we converted the particle-based NOM into a scheme with interpolation property. The new scheme describes partial derivatives of various orders at a point by the nodes in the support and takes advantage of the background mesh for numerical integration. The boundary conditions are enforced via the modified variational principle. The particle-based NOM can be viewed a special case of NOM with interpolation property when nodal integration is used. The scheme based on numerical integration greatly improves the stability of the method, as a consequence, the operator energy functional in particle-based NOM is not required. We demonstrated the capabilities of current method by solving the gradient solid problems and comparing the numerical results with the available exact solutions. In chapter 7, we derived the DS-SPH in solid within the framework of variational principle. The tangent stiffness matrix of SPH can be obtained with ease, and can be served as the basis for the present implicit SPH. We proposed an hourglass energy functional, which allows the direct derivation of hourglass force and hourglass tangent stiffness matrix. The dual-support is {involved} in all derivations based on variational principles and is automatically satisfied in the assembling of stiffness matrix. The implementation of stiffness matrix comprises with two steps, the nodal assembly based on deformation gradient and global assembly on all nodes. Several numerical examples are presented to validate the method. KW - Peridynamik KW - Variational principle KW - weighted residual method KW - gradient elasticity KW - phase field fracture method KW - smoothed particle hydrodynamics KW - numerical methods KW - PDEs Y1 - 2021 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:gbv:wim2-20210412-44039 ER - TY - BOOK A1 - Radecke, Thomas T1 - Der Allgemeine Deutsche Musikverein in der Fachpresse von 1859 bis 1900. Ein Beitrag zur Geschichte der Musikkritik (Texte und Kontexte) N2 - Ohne das fast achtzigjährige Wirken des Allgemeinen Deutschen Musikvereins (ADMV) würde das deutsche Musikleben in seiner heutigen Form nicht existieren. Die kritische Edition Die Musikfeste des Allgemeinen Deutschen Musikvereins von 1859 bis 1937 (Eine Dokumentation der Veranstaltungen), herausgegeben von Jan Neubauer und Thomas Radecke, erschließt bereits erstmals grundlegende Quellen der Programme zu seinen nahezu jährlich anderen Orts veranstalteten Musikfesten und ist ebenfalls hier online abrufbar. Diese Datenbasis vertieft für den Zeitraum von vier deutschen Systemen den Diskurs über Probleme der Repertoirebildung, Institutionalisierung, Kommerzialisierung und Mediation von Musik. 1861 als erster überregionaler deutscher Musikverein mit dem offiziellen Ziel der Integration musikalisch gegensätzlicher zeitgenössischer Richtungen und künstlerischen Nachwuchsförderung konstituiert, trat der ADMV einerseits kosmopolitisch auf, und seine Musikfeste entwickelten sich zu einem Forum für internationale zeitgenössische Musik wie einem Podium für die Wiederentdeckung älterer Musik. Hier erlebten Werke von Richard Strauss, Gustav Mahler und Arnold Schönberg frühe, vielbeachtete Aufführungen. Anderseits reiften parallel dazu protonationalistische Tendenzen zu einem Nationalismus heran, der die Musikfeste 1938 nahtlos in die nationalsozialistischen Reichsmusiktage überführen konnte. Mit dem zur Mitte des 19. Jahrhunderts ausgebrochenen Parteienstreit der Konservativen um Brahms mit der Neudeutschen Schule Liszts und Wagners trat mit der Institutionalisierung der letzteren im ADMV ein bis heute singuläres nationales Musikfestkonzept auf den Plan, das von Anbeginn medial gestützt war: die Tonkünstler-Versammlungen. Vor Ort berichteten neudeutsche Autoren pro domo für das Vereinsorgan Neue Zeitschrift für Musik, was von Rezensenten der konservativen Musikpresse scharf konterkariert wurde und so ein allseitig umfassendes Bild dieser musikalischen Novitätenmessen in ihrem stetigen Wandel abgibt. Diese Publikation ist im von der Deutschen Forschungsgemeinschaft geförderten Projekt Der Allgemeine Deutsche Musikverein (ADMV, 1861–1937) – ein internationales Forum der Musik in Deutschlands Mitte am Gemeinsamen Institut für Musikwissenschaft Weimar-Jena der Hochschule für Musik FRANZ LISZT und der Friedrich-Schiller-Universität entstanden. KW - Fachpresse KW - Musikkritik KW - Geschichte KW - Allgemeiner Deutscher Musikverein KW - Fachpresse KW - Musikkritik KW - Geschichte Y1 - 2021 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:gbv:wim2-20210305-43878 ER - TY - THES A1 - Preis Dutra, Joatan T1 - Cultural Heritage on Mobile Devices: Building Guidelines for UNESCO World Heritage Sites' Apps N2 - Technological improvements and access provide a fertile scenario for creating and developing mobile applications (apps). This scenario results in a myriad of Apps providing information regarding touristic destinations, including those with a cultural profile, such as those dedicated to UNESCO World Heritage Sites (WHS). However, not all of the Apps have the same efficiency. In order to have a successful app, its development must consider usability aspects and features aligned with reliable content. Despite the guidelines for mobile usability being broadly available, they are generic, and none of them concentrates specifically into cultural heritage places, especially on those placed in an open-air scenario. This research aims to fulfil this literature gap and discusses how to adequate and develop specific guidelines for a better outdoor WHS experience. It uses an empirical approach applied to an open-air WHS city: Weimar and its Bauhaus and Classical Weimar sites. In order to build a new set of guidelines applied for open-air WHS, this research used a systematic approach to compare literature-based guidelines to industry-based ones (based on affordances), extracted from the available Apps dedicated to WHS set in Germany. The instructions compiled from both sources have been comparatively tested by using two built prototypes from the distinctive guidelines, creating a set of recommendations collecting the best approach from both sources, plus suggesting new ones the evaluation. N2 - Der technische Fortschritt und der Zugang dazu bieten ein ertragreiches Szenario für die Innovation und Entwicklung mobiler Anwendungen (Apps). Daraus ist eine Vielzahl von zu Verfügung stehenden Apps entstanden, die Informationen über touristische Reiseziele bereitstellen, insbesondere solche mit einem kulturellen Hintergrund, etwa die, die zum UNESCO Welterbe/Weltkulturebe (auf Englisch WHS – World Heritage Sites, fotan so genannt in dieser Arteit) gehören. Allerdings haben nicht alle Apps die gleiche Effizienz. Um eine erfolgreiche App entwickeln zu können, sollten gleichzeitig die Benutzerfreundlichkeit der Aspekte und Funktionen in Betracht gezogen werden, als auch Zuverlässigkeit ihrer Inhalte. Obwohl die Richtlinien für eine mobile Benutzerfreundlichkeit weit verbreitet sind, sind diese jedoch generisch. Keine Richtlinie ist eindeutig auf Orte des Kulturerbes zugeschnitten, schon gar nicht auf Standorte, die sich im Freien befinden. Ziel dieser Arbeit ist es, diese Literaturlücke zu schließen und gleichzeitig nahe zu bringen, wie bestimmte Richtlinien angepasst und ausgebaut werden könnten, um bessere WHS-Erlebnisse im Freien zu schaffen. Die Arbeit geht empirisch vor am Beispiel der deutschen Stadt Weimar, die mit ihren Altstadt- und Bauhaus-Standorten als Freiluft-WHS gilt. Deutschland ist das fünftbedeutsamste Land der UNESCO-Liste und bekannt für sein technologisches Profil und der Zugang dazu. Dieses Land als geeignete Umgebung für den empirischen Ansatz zu wählen ist ein guter Ausgangspunkt, um Erfahrungen zu sammeln für innovative Projekte, die mit Apps das Kulturerbe erschließen. Um eine Reihe neuer Richtlinien für Freiluft-WHS (auf Englisch: Open-Air WHS) aufstellen zu können, wurden im Rahmen dieser Arbeit Richtlinien aus akademischen Quellen mit branchenüblichen Richtlinien verglichen, gewonnen aus einer umfangreichen Auszug verfügbarer Apps, die sich den WHS in Deutschland widmen. Im branchenüblichen Ansatz wurden WHS-bezogene Apps ausgewählt, die auf dem deutschen App-Markt erhältlich sind (für iOS- und Android-Geräte). Deren Eigenschaften und Gebrauch wurden aus der Nutzersicht betrachtet. Daraus ließen sich Gemeinsamkeiten ableiten innerhalb der aktuellen Funktionen und Tools, mit denen WHS beworben werden. Die Analyse förderte Richtlinien hervor fand aus der Layout-, Navigations-, Design- und der Inhaltsperspektive. Daraus wurde eine Prototyp-App erstellt, die dem in der Branche verzeichneten Stand der Technik entspricht. Während die Richtlinien aus der Branchenübersicht einen Beobachtungsansatz der Leistungen verfolgten, bezogen die aus der Literaturrecherche gewonnenen Richtlinien einen systematischen Ansatz des akademischen Materials. Der literaturbasierte Ansatz wurde aus Veröffentlichungen zur Benutzerfreundlichkeit mobiler Apps gewonnen, die in Forschungsdatenbanken erhältlich sind. Zusätzlich wurden in führenden Unternehmen für die Entwicklung von mobilen Betriebssystemen (iOS und Android) bereits vorhandene Modelle zur Nutzerfreundlichkeit sowie offizielle Richtlinien einbezogen, die unterschiedliche Ansätze sowie Ansichten für das Design mobiler Schnittstellen verbinden und kombinieren und die für WHS genutzt werden könnten. Unter Rücksichtnahme der Vielfalt der Besucherprofile in Weimar wurden auch Studien über Nutzeroberflächen für ältere Nutzer eingeschlossen. Obwohl die Leitlinien sich nicht auf didaktische Funktionen konzentrieren, wurden auch Studien über das mobile Lernen in der Studie mitaufgenommen, sofern die Nutzeroberfläche Teil des Studienziels war. Diese Entscheidung wurde getroffen, weil die Stadt Weimar auch jugendliche Studenten als Besucher hat, die die historischen Sehenswürdigkeiten der Stadt besuchen und kennenlernen. Allgemein konzentrierte sich diese Ausarbeitung auf klare Anweisungen, die in Richtlinien umgesetzt werden könnten. Die Analyse beschränkte sich jedoch nicht auf die Auswahlliste der Studienobjekte und wurde extrapoliert, unter Berücksichtigung relevanter Referenzen, die in den für die Stichprobe ausgewählten Veröffentlichungen zitiert wurden. Wann immer eine Leitlinie oder Empfehlung gefunden werden konnte, wurde diese, verfahrensgemäß in eine Tabelle eingefügt, einer ähnlichen Struktur folgend zu den aus der Übersicht der App-Industrie gewonnenen Richtlinien. Um den Erkenntnissen der Literaturrecherche zu entsprechen, wurden neue Kategorien hinzugefügt. Im Großen und Ganzen bestätigten einige Richtlinien des literarischen Ansatzes die Anweisungen des branchenorientierten Ansatzes, andere widersprachen diesen. Dadurch konnte ein neuer Satz von Leitlinien entstehen, die gegeneinander getestet wurden. Der Inhalt beider Prototypen (branchen- und literaturbasiert) wurden ausgearbeitet, um das WHS in Weimar anzusprechen. Dabei wurden Inhalte abgerufen, die auf der offiziellen touristischen Website der Stadt und in der größten Kulturstiftung Weimars, der Klassik Stiftung, verfügbar sind. Die Nutzung zweier verschiedener einfache Prototypen bot die Möglichkeit, auch andere Funktionen zu testen wie z. B. verschiedene Arten der Anzeige von Karten und Inhalten. Zur Überprüfung und Gegenüberstellung der verschiedenen Leitlinien, wurden ein aufgabenbasierter Test und eine vergleichende Bewertungsumfrage durchgeführt. Tester aus verschiedenen Altersgruppen führten in beiden Prototypen eine Reihe vordefinierter Aufgaben aus und beantworteten einen Fragebogen, wobei die in beiden Versionen vorgestellten Funktionen und Formate verglichen werden konnten. Die Fragen sollten anhand eine Auswahl vordefinierter Antworten von Nutzern beantwortet werden, ideal für eine statistische Auswertung, insbesondere zum Thema Benutzerzufriedenheit. Auch offene Fragen, zur Leistung persönliche Beiträge der Tester, wurden angeboten. Diese Methode war ausschlaggebend dafür, beide Richtliniensätze (Industrie vs. Literaturrecherche) gegeneinander zu vergleichen und zu analysieren, So konnte ein idealer Ansatz gefunden werden für Richtlinien von Apps, die sich mit Welterbestätten unter freiem Himmel befassen. Auch weitere Empfehlungen, die sich aus der Bewertung ergaben, konnten hinzugefügt werden. Das Ergebnis führt zu einem umfassendem Satz von Richtlinien, die in zukünftigen touristischen Open-Air-Apps angewandt werden können, die sich mit Weltkulturerbestätten befassen. KW - Benutzerschnittstellenentwurfssystem KW - Welterbe KW - Benutzerfreundlichkeit KW - App KW - Mobiles Endgerät KW - Interface Design KW - world heritage sites KW - usability KW - mobile devices Y1 - 2021 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:gbv:wim2-20211129-45319 UR - www.joatan.com.br/docs/Thesis_JoatanPreisDutra.pdf ER - TY - THES A1 - Potocka, Anna T1 - Wearables: Kontrollregime zwischen Affekt und Technologie N2 - Überwachungspraktiken und –technologien sind in der heutigen Welt omnipräsent und wohl nicht mehr wegzudenken. Ob CCTV-Systeme, Biometrie oder Data Mining – unsere Gesellschaft befindet sich in einem ständigen Überwachungsmodus, der sich weit über einen begrenzten Raum oder zeitlichen Rahmen hinausstreckt. Überwacht wird überall: privat, am Arbeitsplatz oder im Cyberspace, und alles: Interaktionen, Äußerungen, Verhalten. Es werden Unmengen von Daten gesammelt, strukturiert, kombiniert, gekauft und verkauft. Dieser Modus stellt mehr als eine bloße Neuauflage des Bentham-Foucaultschen Panoptikons dar: der aktuelle Überwachungsmodus, die informationelle Asymmetrie als ihren tragenden Pfeiler beibehaltend, dient nicht nur der Disziplinierung, sondern viel mehr der Kontrolle, die nicht primär negativ-sanktionierend, sondern positiv-leistungssteigernd wirkt: es ist nicht das Ziel, die Individuen zu bestrafen und ein bestimmtes Verhalten zu verbieten, sondern sie durch Belohnung, Interaktion und spielerische Elemente dazu zu bringen, sich auf die gewünschte Art zu verhalten und im Endeffekt sich selbst zu überwachen. Die Kontrolle wird auf diese Weise zum zentralen Schauplatz der Machtausübung, die sich über das Beobachten, Speichern, Auswerten und Sortieren vollzieht. Diese Prozesse hinterlassen keinen Frei- oder Spielraum für Ambiguität; sie verwirklichen die Diktatur der klaren Kante, der Klassifizierung und Kategorisierung ohne Schattierungen. Die Macht selbst befindet sich in einem kontinuierlichen Fluss, sie ist ubiquitär, dennoch schwer lokalisierbar. Sie fungiert nicht mehr unter dem Signum einer pseudosakralen zentralen Instanz, sondern wird durch diverse Akteure und Assemblages kolportiert. Die durch sie implizierten Praktiken der Selbstkontrolle, kulturgeschichtlich ebenfalls religiös oder zumindest philosophisch konnotiert, sind die neuen Rituale des Sehens und Gesehen-Werdens. Im Zeitalter der elektronischen Datentechnologien gibt es diverse Agenten der Überwachung. Vom besonderen Interesse sind dabei die Wearables, weil sie intim, affektiv und haptisch arbeiten und so, über das Sehen und Gesehen-Werden hinaus, das Berühren und Berührt-Werden und somit die Neuregulierung von Nähe und Distanz ins Spiel bringen. Sie schreiben sich zwar in eine Vermessungstradition eins, die ihre Ursprünge mindestens im 19. Jahrhundert hat, unterscheiden sich aber von dieser in ihrer Intensität und Sinnlichkeit. KW - Technologie KW - Wearables KW - Medien KW - Überwachung KW - Kontrolle KW - Objektverfolgung Y1 - 2021 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:gbv:wim2-20210713-44594 ER - TY - THES A1 - Pereyra, Ailén Suyai T1 - Continuidades, tensiones y rupturas en las prácticas del habitar, en el marco de las transformaciones de barrios ‘tradicionales’. El Caso de barrio Güemes 2000-2016 T1 - Continuities, tensions and breakdowns in the inhabit practices, in the framework of the transformations of 'traditional' neighborhoods. The case of Güemes neighborhood 2000-2016 N2 - El presente trabajo se inscribe en el campo de los estudios urbanos y plantea como ejes estructurantes la intersección entre las políticas públicas, el barrio y las prácticas del habitar (de Certeau, 1996, 1999; Gravano, 2003) en el marco de las transformaciones del espacio urbano en los barrios pericentrales, también denominados tradicionales de la ciudad de Córdoba, particularmente lo acontecido en Barrio Güemes, durante el periodo 2010-2016. El propósito del abordaje se inscribe en conocer y realizar aportes generalizables a la comprensión de las prácticas del habitar como unidad de análisis. En ese marco, el problema de investigación se formula en el siguiente interrogante: ¿cómo se modifican las prácticas del habitar en el marco de las transformaciones urbanas, en un modo de producción capitalista? Se entiende a las prácticas como acciones elementales de las “artes de hacer” que las personas ordinarias ponen en marcha en su vida cotidiana: para circular, cocinar, trabajar, vincularse. También, a través de las mismas resignifican los espacios, les otorgan una valoración (positiva o negativa), se identifican como parte de la identidad y a su vez se reconocen lugares de (des)encuentro y vías de circulación. Para su abordaje se toma como unidad de estudio el caso de barrio Güemes. El recorte espacial (o físico) del trabajo empírico está localizado en la ciudad de Córdoba, y se sitúa en la periferia del área central. Esta localización permite comprender el surgimiento de las primeras expansiones urbanas como consecuencia del crecimiento demográfico y cómo estas, se transformaron en los primeros barrios. El recorte temporal se encuentra delimitado entre los años 2000 y 2016, respaldado intencionalmente por dos acontecimientos significativos: el censo de población (2001) y la celebración del Bicentenario de la Independencia en Argentina. Los cambios materializados en ciertos espacios urbanos, tanto en ciudades latinoamericanas (Buenos Aires, Salvador de Bahía en Brasil, México Distrito Federal, etc.) como en otras partes del mundo (New Orleans en los Estados Unidos, el distrito de Kreuzberg- Friedrichshain en Berlín, el puerto de Hamburgo en Alemania, etc.) demuestran cómo estos espacios se van transformado acorde al modo de reproducción capitalista. Pues, se trataba de espacios que en algún momento cumplieron funciones económicas-sociales jerarquizadas y luego por la dinámica misma del capitalismo, la sobreacumulación, dejan de ser rentables y pasan a ser espacios “obsoletos”. En ese sentido, la omisión de acciones públicas y/o privadas, la desatención y el crecimiento de situaciones sociales conflictivas (delitos, inseguridad, degradación) en estos espacios, funciona como argumento para que los gobiernos locales comiencen a planear el futuro y modernizarlos. De esta manera, se plantean políticas urbanas con el objetivo de impulsar acciones de renovación o rehabilitación para dinamizar económicamente determinados sectores. Dos elementos discursivos aparecen como posibilitadores del proceso de renovación urbana: el turismo y el patrimonio. En ese sentido, bajo la recuperación patrimonial de ciertos lugares se dinamizan los territorios, por lo que el turismo se vuelve una herramienta económica que produce un excedente de plusvalía. La puesta en valor de bienes tangibles e intangibles atrae la afluencia de visitantes y, a la vez, es rentable económicamente. Ahora bien, muchas veces los proyectos tienen en cuenta las variables morfológicas y físicas, dejando en un segundo plano el impacto en el espacio próximo y las relaciones entre los habitantes con su territorio. Actualmente los espacios elegidos por los municipios para la intervención pública y/o privada son los barrios, puesto que son espacios cercanos al centro y considerados estratégicos. Por lo general, el argumento es la necesidad de rehabilitar/renovar zonas poco aprovechadas o degradadas con el objetivo de mejorar la calidad de vida de la población y dinamizar el sector (Brites, 2017; Guevara, 2012). Desde los 2000 el barrio Güemes asiste a un proceso de crecimiento inusitado. La cantidad de artesanos se disparó y variedad de productos ofrecidos, emergieron los comercios que forman parte de la oferta comercial, gastronómica y cultural del barrio. Hace varios años, presenta nuevos actores económicos que se pueden observar en la apertura de galerías comerciales; ubicadas sobre el eje de las calles Belgrano, Achával Rodríguez, Fructuoso Rivera y la creciente aparición de edificaciones alrededor de la feria artesanal histórica; con la venta y exposición de piezas del arte plástico, gastronomía, negocios de diseñadores cordobeses y hasta la inclusión de la idea del del “desarrollo sustentable” en los techos de las galerías. La modificación del corpus normativo, la aparición de edificación en altura y el boom económico tuvieron como resultado, la valorización del suelo urbano, la retroalimentación en el espacio con el emplazamiento de nuevas actividades comerciales y servicios culturales. A la par, en el espacio barrial se presentan nuevos residentes con otros hábitos y prácticas que ponen en disputa los modos de habitar en el espacio. A riesgo de simplificar, estas transformaciones fueron producto de los cambios políticoideológicos, de los modelos e instrumentos de gestión urbana puestos en juego en los diversos momentos históricos y de las propias prácticas sociales y culturales de los habitantes. De esta manera, se centrará la mirada analítica en las transformaciones de las prácticas del habitar de los pobladores de los Barrios Güemes, en el marco de la metamorfosis del espacio urbano (atravesado por tendencias de mediatización y mercantilización de la experiencia) que conjugó un proceso de intersección y asociatividad entre políticas públicas y expansión inmobiliaria. N2 - This work is part of the field of urban studies and proposes as structuring axes the intersection between public policies, the neighborhood and the inhabit practices (de Certeau, 1996, 1999; Gravano, 2003) in the framework of the transformations of the urban space in the pericentral neighborhoods, also known as traditional neighborhoods in the city of Córdoba, particularly what happened in Barrio Güemes, during the period 2010-2016. The purpose of the approach is inscribed in knowing and making generalizable contributions to the understanding of the inhabit practices as a unit of analysis. In this framework, the research problem is formulated in the following question: how are living practices modified in the framework of urban transformations, in a capitalist mode of production? The practices are understood as elementary actions of the "arts of doing" that ordinary people implement in their daily lives: to circulate, to cook, to work, to connect. Also, through them they resignify the spaces, give them an assessment (positive or negative), identify themselves as part of the identity and, in turn, recognize places of (dis) encounter and circulation path. For this approach, the case of Güemes neighborhood is taken as a unit of study. The spatial (or physical) clipping of the empirical work is located in the city of Córdoba, and is located on the periphery of the central area. This location allows us to understand the emergence of the first urban expansions as a consequence of demographic growth and how these were transformed into the first neighborhoods. The temporary cut is delimited between the years 2000 and 2016, intentionally supported by two significant events: the population census (2001) and the celebration of the Bicentenario de la Independencia de Argentina (Bicentennial of Independence in Argentina). The changes materialized in certain urban spaces, both in Latin American cities (Buenos Aires, Salvador de Bahía in Brazil, Mexico City, etc.) and in other parts of the world (New Orleans in the United States, the district of Kreuzberg-Friedrichshain in Berlin, the port of Hamburg in Germany, etc.) demonstrate how these spaces are transformed according to the capitalist mode of reproduction. Since these were spaces that at some point fulfilled hierarchical economic- social functions and later, due to the very dynamics of capitalism, the over-accumulation, they stopped being profitable and became “obsolete” spaces. In this sense, the omission of public and / or private actions, the neglect and growth of conflictive social situations (crime, insecurity, degradation) in these spaces, works as an argument for local governments to start planning the future and modernizing them. In this way, urban policies are proposed with the aim of promoting renovation or rehabilitation actions to economically boost certain sectors. Two discursive elements appear as enablers of the urban renewal process: tourism and patrimony. In this sense, under the patrimonial recovery of certain places, the territories are made more dynamic, so that tourism becomes an economic tool that produces an excess of surplus value. The punt in value of tangible and intangible assets attracts the influx of visitors and, at the same time, is economically profitable. However, projects often take into account morphological and physical variables, leaving in the background the impact on the nearby space and the relationships between the inhabitants and their territory. Currently the spaces chosen by the municipalities and for public and/or private intervention are the neighborhoods, since they are spaces close to the center and considered strategic. In general, the argument is the need to rehabilitate or renovate little-used or degraded areas in order to improve the quality of life of the population and boost the sector (Brites, 2017; Guevara, 2012). Since the 2000s, the neighborhood has witnessed an unusual growth process. The number of craftsmen skyrocketed and the variety of products offered, the businesses that are part of the commercial, gastronomic and cultural offer of the neighborhood emerged. For several years, it has introduced new economic actors that can be observed in the opening of commercial galleries; located on the axis of the streets Belgrano, Achával Rodríguez, Fructuoso Rivera and the growing appearance of buildings around the historic artisan fair; where it is sold and exhibited different pieces of plastic art, gastronomy, businesses of cordobes designers and even the inclusion of the idea of "sustainable development" in the ceilings of the galleries. The modification of the normative corpus, the appearance of high-rise buildings and the economic boom resulted in: the valorization of urban land, feedback in space with the location of new commercial activities and cultural services. At the same time, new residents appeared in the neighborhood space with other habits and practices that dispute the ways of living in the place. At the risk of simplification, these transformations were the product of the political-ideological changes, of the urban management models and instruments put into play in the various historical moments, and of the inhabitants' own social and cultural practices. In this way, the analytical look will focus on the transformations of the inhabitat practices of the residents of the Güemes neighbourhood, within the framework of the metamorphosis of the urban space (crossed by tendencies of mediatization and commercialization of the experience) that combined a process of intersection and associativity between public policies and real estate expansion. KW - Stadtviertel KW - Kommerzialisierung KW - barrio KW - Políticas públicas KW - Transformaciones urbanas KW - prácticas del habitar KW - mercantilización KW - Stadtumbau KW - Wohnen Y1 - 2021 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:gbv:wim2-20220524-46511 UR - https://rdu.unc.edu.ar/handle/11086/21959 ER - TY - THES A1 - Pantzier, Richard T1 - In Neuer Frische. Die Sommerfrische Schwarzatal als regional selbstbestimmte Form des historischen Phänomens Sommerfrische? N2 - Als Frühform des Tourismus war die Sommerfrische ab Mitte des 19. Jahrhunderts eng mit der flächendeckenden Verstädterung in Mitteleuropa und der Herausbildung eines urbanen Bürgertums verknüpft. Nachdem sich der Begriff in der zweiten Hälfte des 20. Jahrhunderts im Sprachgebrauch verlor, erfährt er gegenwärtig - auch im Zuge einer neuen positiven Konnotation des Ländlichen - eine Art Renaissance. Im Schwarzatal als einer historischen Zielregion dieser Reisepraxis arbeitet der lokale Verein Zukunftswerkstatt Schwarzatal gemeinsam mit der IBA Thüringen an einer zeitgenössischen Form der Sommerfrische, die auch Antworten auf den tiefgreifenden Strukturwandel nach 1989 geben soll. Die Arbeit thematisiert die programmatische Renaissance der Sommerfrische im Schwarzatal und stellt sie dem historischen Phänomen der Sommerfrische des 19. und 20. Jahrhunderts unter den drei Forschungsfragen gegenüber. Die Forschungsfragen nehmen Bezug auf die soziale, die materielle sowie die symbolische Dimension der Raumkonstitution beider Sommerfrischen, indem nach den jeweiligen Akteuren, den Regeln der physischen Umgestaltung sowie den hegemonialen Vorstellungen über die Zielorte gefragt wird. Die Arbeit ordnet sich entsprechend in eine sozialkonstruktivistische Geographie des Ländlichen ein. Sie gibt schließlich Auskunft darüber, warum es sich bei der Sommerfrische Schwarzatal um eine regional selbstbestimmte Form der Sommerfrische handelt. T3 - IfEU.OPEN - 4 KW - Sommerfrische KW - Stadt-Land-Beziehung KW - Thüringen KW - Verstädterung KW - Kulturlandschaft KW - Raumproduktion KW - historischer Vergleich Y1 - 2021 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:gbv:wim2-20210924-45055 ER - TY - GEN A1 - Nöske, Lilo T1 - Corviale en dérive N2 - Corviale en dérive ist eine Reise vom Zentrum Roms bis hin in dessen Peripherie. Sie gleicht einem situationistischen Spaziergang, welcher eine äußerst befreiende Übung darstellt und die uns, wo immer wir uns auch auf dieser Welt befinden mögen, stets ein wenig Leichtigkeit schenken kann. T3 - LUCIA Open Paper - 4 KW - Architektur KW - Rom Y1 - 2021 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:gbv:wim2-20210603-44399 VL - 2021 PB - Lucia Verlag CY - Weimar ER - TY - JOUR A1 - Noori, Hamidreza A1 - Mortazavi, Bohayra A1 - Keshtkari, Leila A1 - Zhuang, Xiaoying A1 - Rabczuk, Timon T1 - Nanopore creation in MoS2 and graphene monolayers by nanoparticles impact: a reactive molecular dynamics study JF - Applied Physics A N2 - In this work, extensive reactive molecular dynamics simulations are conducted to analyze the nanopore creation by nano-particles impact over single-layer molybdenum disulfide (MoS2) with 1T and 2H phases. We also compare the results with graphene monolayer. In our simulations, nanosheets are exposed to a spherical rigid carbon projectile with high initial velocities ranging from 2 to 23 km/s. Results for three different structures are compared to examine the most critical factors in the perforation and resistance force during the impact. To analyze the perforation and impact resistance, kinetic energy and displacement time history of the projectile as well as perforation resistance force of the projectile are investigated. Interestingly, although the elasticity module and tensile strength of the graphene are by almost five times higher than those of MoS2, the results demonstrate that 1T and 2H-MoS2 phases are more resistive to the impact loading and perforation than graphene. For the MoS2nanosheets, we realize that the 2H phase is more resistant to impact loading than the 1T counterpart. Our reactive molecular dynamics results highlight that in addition to the strength and toughness, atomic structure is another crucial factor that can contribute substantially to impact resistance of 2D materials. The obtained results can be useful to guide the experimental setups for the nanopore creation in MoS2or other 2D lattices. KW - Nanomechanik KW - Molekülstruktur KW - Nanoporöser Stoff KW - MoS2 KW - molecular dynamics KW - Nanopore KW - Graphene Y1 - 2021 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:gbv:wim2-20210804-44756 UR - https://link.springer.com/article/10.1007/s00339-021-04693-5 VL - 2021 IS - volume 127, article 541 SP - 1 EP - 13 PB - Springer CY - Heidelberg ER - TY - JOUR A1 - Noeske, Jannik T1 - Die Zukunft war jetzt BT - Rezension zu Christina Schwenkel (2020): Building socialism. The afterlife of East German architecture in urban Vietnam . Durham: Duke University Press. JF - sub\urban. Zeitschrift für Kritische Stadtforschung N2 - Die US-amerikanische Kulturanthropologin Christina Schwenkel legt mit Building socialism eine quellengesättigte ethnografische Studie über Zerstörung, Wiederaufbau und Nutzungsperspektiven der vietnamesischen Stadt Vinh vor. Ein besonderes Augenmerk liegt auf den agencies der Beteiligten. Im Zentrum der Untersuchung steht ein Quartier, dessen Wohnblocks mit materieller und ideeller Unterstützung der DDR errichtet wurden. Nicht nur sind die methodischen Zugänge der Untersuchung vielversprechend und gewinnbringend – angesichts des drohenden Stadtumbaus, der für die Bewohner:innen des Quartiers Quang Trung Abriss und Verdrängung bedeuten würde, gewinnt ihre städtebauhistorische Ethnografie auch an politischer Relevanz. KW - Vietnam KW - Deutschland KW - Sozialismus KW - Städtebau KW - Vietnam KW - Ethnografie KW - DDR KW - Städtebaugeschichte KW - Rezension KW - OA-Publikationsfonds2021 Y1 - 2021 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:gbv:wim2-20220112-45573 UR - https://zeitschrift-suburban.de/sys/index.php/suburban/article/view/711 VL - 2021 IS - Band 9, Nr. 3/4 SP - 397 EP - 402 PB - sub\urban e. V. CY - Berlin ER - TY - JFULL A1 - Neubauer, Jan A1 - Radecke, Thomas ED - Neubauer, Jan ED - Radecke, Thomas T1 - Die Musikfeste des Allgemeinen Deutschen Musikvereins von 1859 bis 1937 (Eine Dokumentation der Veranstaltungen). Kritische Edition, herausgegeben von Jan Neubauer und Thomas Radecke N2 - Ohne das fast achtzigjährige Wirken des Allgemeinen Deutschen Musikvereins (ADMV) würde das deutsche Musikleben in seiner heutigen Form nicht existieren. Die Dokumentation der Programme zu seinen von 1859 bis 1937 nahezu jährlich anderen Orts veranstalteten Musikfesten erschließt erstmals grundlegende Quellen hierzu. Diese Datenbasis vertieft für den Zeitraum von vier deutschen Systemen den Diskurs über Probleme der Repertoirebildung, Institutionalisierung, Kommerzialisierung und Mediation von Musik. 1861 als erster überregionaler deutscher Musikverein mit dem offiziellen Ziel der Integration musikalisch gegensätzlicher zeitgenössischer Richtungen und künstlerischen Nachwuchsförderung konstituiert, trat der ADMV einerseits kosmopolitisch auf, und seine Musikfeste entwickelten sich zu einem Forum für internationale zeitgenössische Musik wie einem Podium für die Wiederentdeckung älterer Musik. Hier erlebten Werke von Richard Strauss, Gustav Mahler und Arnold Schönberg frühe, vielbeachtete Aufführungen. Anderseits reiften parallel dazu protonationalistische Tendenzen zu einem Nationalismus heran, der die Musikfeste 1938 nahtlos in die nationalsozialistischen Reichsmusiktage überführen konnte. Nach zahlreichen Standortwechseln sind die nunmehr restaurierten Materialien der einstigen Vereinsbibliothek und Vereinsakten im Hochschularchiv / Thüringischen Landesmusikarchiv Weimar sowie Goethe- und Schiller-Archiv Weimar wieder zugänglich. So wird jetzt eine erste kritische Edition der Festprogramme angeboten, in welcher die Programmfolge zu jeder Aufführung mit Werkangaben und dem Nachweis der Aufführenden prozessual von der Planung bis zur Präzisierung und Ergänzung bzw. Modifizierung rekonstruiert wurde. Darüber hinaus werden alle wissenschaftlichen Vorträge, Haupt- u. a. Versammlungen, Beratungen und die gesamten Personalia des Vereins und der jeweiligen Lokalkomitees dokumentiert sowie lassen sich Komponisten und Interpreten über Indizes erschließen. Diese Publikation ist im von der Deutschen Forschungsgemeinschaft geförderten Projekt Der Allgemeine Deutsche Musikverein (ADMV, 1861–1937) – ein internationales Forum der Musik in Deutschlands Mitte am Gemeinsamen Institut für Musikwissenschaft Weimar-Jena der Hochschule für Musik FRANZ LISZT und der Friedrich-Schiller-Universität entstanden. KW - Musikfest KW - Allgemeiner Deutscher Musikverein KW - Musikfest KW - Dokumentation KW - Edition Y1 - 2021 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:gbv:wim2-20210305-43861 ER - TY - JOUR A1 - Müller, Matthias A1 - Ludwig, Horst-Michael A1 - Tange Hasholt, Marianne T1 - Salt frost attack on concrete: the combined effect of cryogenic suction and chloride binding on ice formation JF - Materials and Structures N2 - Scaling of concrete due to salt frost attack is an important durability issue in moderate and cold climates. The actual damage mechanism is still not completely understood. Two recent damage theories—the glue spall theory and the cryogenic suction theory—offer plausible, but conflicting explanations for the salt frost scaling mechanism. The present study deals with the cryogenic suction theory, which assumes that freezing concrete can take up unfrozen brine from a partly frozen deicing solution during salt frost attack. According to the model hypothesis, the resulting saturation of the concrete surface layer intensifies the ice formation in this layer and causes salt frost scaling. In this study an experimental technique was developed that makes it possible to quantify to which extent brine uptake can increase ice formation in hardened cement paste (used as a model material for concrete). The experiments were carried out with low temperature differential scanning calorimetry, where specimens were subjected to freeze–thaw cycles while being in contact with NaCl brine. Results showed that the ice content in the specimens increased with subsequent freeze–thaw cycles due to the brine uptake at temperatures below 0 °C. The ability of the hardened cement paste to bind chlorides from the absorbed brine at the same time affected the freezing/melting behavior of the pore solution and the magnitude of the ice content. KW - Beton KW - Frost KW - Beton KW - Frostangriff KW - salt frost attack KW - cryogenic suction KW - chloride binding Y1 - 2021 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:gbv:wim2-20211207-45392 UR - https://link.springer.com/article/10.1617/s11527-021-01779-7 VL - 2021 IS - issue 54, article 189 SP - 1 EP - 16 ER - TY - THES A1 - Müller, Matthias T1 - Frost-Tausalz-Angriff auf Beton - Neue Erkenntnisse zum Schadensmechanismus N2 - Für die Verminderung der betonspezifischen CO2-Emissionen wird ein verstärkter Einsatz klinkerreduzierter Zemente bzw. Betone angestrebt. Die Reduzierung des Klinkergehaltes darf jedoch nicht zu einer lebensdauerrelevanten Beeinträchtigung der Betondauerhaftigkeit führen. In diesem Zusammenhang stellt der Frost-Tausalz-Widerstand eine kritische Größe dar, da er bei höheren Klinkersubstitutionsraten häufig negativ beeinflusst wird. Erschwerend kommt hinzu, dass für klinkerreduzierte Betone nur ein unzureichender Erfahrungsschatz vorliegt. Ein hoher Frost-Tausalz-Widerstand kann daher nicht ausschließlich anhand deskriptiver Vorgaben gewährleistet werden. Demgemäß sollte perspektivisch auch für frost-tausalzbeanspruchte Bauteile eine performancebasierte Lebensdauerbetrachtung erfolgen. Eine unverzichtbare Grundlage für das Erreichen dieser Ziele ist ein Verständnis für die Schadensvorgänge beim Frost-Tausalz-Angriff. Der Forschungsstand ist jedoch geprägt von widersprüchlichen Schadenstheorien. Somit wurde als Zielstellung für diese Arbeit abgeleitet, die existierenden Schadenstheorien unter Berücksichtigung des aktuellen Wissensstandes zu bewerten und mit eigenen Untersuchungen zu prüfen und einzuordnen. Die Sichtung des Forschungsstandes zeigte, dass nur zwei Theorien das Potential haben, den Frost-Tausalz-Angriff umfassend abzubilden – die Glue Spall Theorie und die Cryogenic Suction Theorie. Die Glue Spall Theorie führt die Entstehung von Abwitterungen auf die mechanische Schädigung der Betonoberfläche durch eine anhaftende Eisschicht zurück. Dabei sollen nur bei moderaten Tausalzkonzentrationen in der einwirkenden Lösung kritische Spannungszustände in der Eisschicht auftreten, die eine Schädigung der Betonoberfläche hervorrufen können. In dieser Arbeit konnte jedoch nachgewiesen werden, dass starke Abwitterungen auch bei Tausalz¬konzentrationen auftreten, bei denen eine mechanische Schädigung des Betons durch das Eis auszuschließen ist. Damit wurde die fehlende Eignung der Glue Spall Theorie aufgezeigt. Die Cryogenic Suction Theorie fußt auf den eutektischen Eigenschaften von Tausalz-lösungen, die im gefrorenen Zustand immer als Mischung auf festem Wassereis und flüssiger, hochkonzentrierter Salzlösung bestehen, solange ihre Eutektikumstemperatur nicht unter¬schritten wird. Die flüssige Phase im salzhaltigen Eis stellt für gefrorenen Beton ein bisher nicht berücksichtigtes Flüssigkeitsreservoir dar, welches trotz der hohen Salzkonzentration die Eisbildung in der Betonrandzone verstärken und so die Entstehung von Abwitterungen verursachen soll. In dieser Arbeit wurde bestätigt, dass die Eisbildung im Zementstein beim Gefrieren in hochkonzentrierter Tausalzlösung tatsächlich verstärkt wird. Das Ausmaß der zusätzlichen Eisbildung wurde dabei auch von der Fähigkeit des Zementsteins zur Bindung von Chloridionen aus der Tausalzlösung beeinflusst. Zusammenfassend wurde festgestellt, dass die Cryogenic Suction Theorie eine gute Beschreibung des Frost-Tausalz-Angriffes darstellt, aber um weitere Aspekte ergänzt werden muss. Die Berücksichtigung der intensiven Sättigung von Beton durch den Prozess der Mikroeislinsenpumpe stellt hier die wichtigste Erweiterung dar. Basierend auf dieser Überlegung wurde eine kombinierte Schadenstheorie aufgestellt. Wichtige Annahmen dieser Theorie konnten experimentell bestätigt werden. Im Ergebnis wurde so die Grundlage für ein tiefergehendes Verständnis des Frost-Tausalz-Angriffes geschaffen. Zudem wurde ein neuer Ansatz identifiziert, um die (potentielle) Verringerung des Frost-Tausalz-Widerstandes klinkerreduzierter Betone zu erklären. N2 - The reduction of the cement clinker content is an important prerequisite for the improvement of the CO2-footprint of concrete. Nevertheless, the durability of such concretes must be sufficient to guarantee a satisfactory service life of structures. Salt frost scaling resistance is a critical factor in this regard, as it is often diminished at increased clinker substitution rates. Furthermore, only insufficient long-term experience for such concretes exists. A high salt frost scaling resistance thus cannot be achieved by applying only descriptive criteria, such as the concrete composition. It is therefore to be expected, that in the long term a performance based service life prediction will replace the descriptive concept. To achieve the important goal of clinker reduction for concretes also in cold and temperate climates it is important to understand the underlying mechanisms for salt frost scaling. However, conflicting damage theories dominate the current State of the Art. It was consequently derived as the goal of this thesis to evaluate existing damage theories and to examine them experimentally. It was found that only two theories have the potential to describe the salt frost attack satisfactorily – the glue spall theory and the cryogenic suction theory. The glue spall theory attributes the surface scaling to the interaction of an external ice layer with the concrete surface. Only when moderate amounts of deicing salt are present in the test solution the resulting mechanical properties of the ice can cause scaling. However, the results in this thesis indicate that severe scaling also occurs at deicing salt levels, at which the ice is much too soft to damage concrete. Thus, the inability of the glue spall theory to account for all aspects of salt frost scaling was shown. The cryogenic suction theory is based on the eutectic behavior of salt solutions, which consist of two phases – water ice and liquid brine – between the freezing point and the eutectic temperature. The liquid brine acts as an additional moisture reservoir, which facilitates the growth of ice lenses in the surface layer of the concrete. The experiments in this thesis confirmed, that the ice formation in hardened cement paste increases due to the suction of brine at sub-zero temperatures. The extent of additional ice formation was influenced mainly by the porosity and by the chloride binding capacity of the hardened cement paste. Consequently, the cryogenic suction theory plausibly describes the actual generation of scaling, but it has to be expanded by some crucial aspects to represent the salt frost scaling attack completely. The most important aspect is the intensive saturation process, which is ascribed to the so-called micro ice lens pump. Therefore a combined damage theory was proposed, which considers multiple saturation processes. Important aspects of this combined theory were confirmed experimentally. As a result, the combined damage theory constitutes a good basis to understand the salt frost scaling attack on concrete on a fundamental level. Furthermore, a new approach was identified, to account for the reduced salt frost scaling resistance of concretes with reduced clinker content. KW - Beton KW - Frost KW - Beton KW - Frost-Tausalz-Angriff KW - Schadensmechanismus KW - Concrete KW - Salt-Frost-Attack Y1 - 2021 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:gbv:wim2-20210922-45025 ER - TY - RPRT A1 - Müller, Christoph A1 - Seidel, Maik A1 - Ludwig, Horst-Michael A1 - Müller, Matthias T1 - Prüfung des Frost-Tausalz-Widerstandes von Beton für die Expositionsklasse XF2 N2 - In cold and moderate climates concrete can be subjected to a combined salt frost attack, which can cause scaling damage. Consequently, numerous test procedures were developed to determine the resistance of concrete compositions against this kind of attack. These tests typically mimic a severe attack with high levels of saturation, e.g. as for concrete pavements. Very few approaches exist for testing the salt frost scaling resistance of concretes, which are subjected only to medium levels of saturation, as such concrete elements typically don’t show notable scaling damage. However, the increasing use of low carbon cements with high clinker substitution rates might affect the salt frost scaling resistance of such concrete elements to some extent. To ensure adequate durability of such concretes it is thus desirable to determine their performance in an actual test procedure instead of relying on past experience. Thus, less severe test methods was developed, which are based on the Slab test and the CDF test, repectively. N2 - In kalten und gemäßigten Klimazonen kann Beton einem kombinierten Frost-Tausalz-Angriff ausgesetzt sein, der zu Schäden in Form von Abwitterungen führen kann. Daher wurden zahlreiche Prüfverfahren entwickelt, um die Widerstandsfähigkeit von Betonzusammensetzungen gegen diese Art des Angriffs zu bestimmen. Diese Tests simulieren in der Regel einen starken Angriff mit hohen Sättigungsgraden, wie z. B. bei Betonfahrbahnen. Es gibt nur sehr wenige Ansätze für die Prüfung des Widerstands von Betonen, die nur einem mittleren Sättigungsgrad ausgesetzt sind, da solche Betonelemente in der Regel keine nennenswerten Abwitterungen aufweisen. Die zunehmende Verwendung von klinkereffizienten Zementen könnte sich jedoch in gewissem Maße auf den Frost-Tausalz-Widerstand solcher Betonelemente auswirken. Um eine angemessene Dauerhaftigkeit zu gewährleisten ist es daher wünschenswert, ihre Leistungsfähigkeit in einem tatsächlichen Prüfverfahren zu ermitteln, anstatt sich auf Erfahrungswerte zu verlassen. Daher wurden Ansätze für abgeschwächte Prüfverfahren entwickelt, die auf dem Slab-Test bzw. dem CDF-Test beruhen. KW - Beton KW - Frost KW - Prüfverfahren KW - Beton KW - Frost-Tausalz-Widerstand KW - XF2 KW - CDF KW - Slab-Test Y1 - 2021 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:gbv:wim2-20240226-48877 ER - TY - JOUR A1 - Meiabadi, Mohammad Saleh A1 - Moradi, Mahmoud A1 - Karamimoghadam, Mojtaba A1 - Ardabili, Sina A1 - Bodaghi, Mahdi A1 - Shokri, Manouchehr A1 - Mosavi, Amir Hosein T1 - Modeling the Producibility of 3D Printing in Polylactic Acid Using Artificial Neural Networks and Fused Filament Fabrication JF - polymers N2 - Polylactic acid (PLA) is a highly applicable material that is used in 3D printers due to some significant features such as its deformation property and affordable cost. For improvement of the end-use quality, it is of significant importance to enhance the quality of fused filament fabrication (FFF)-printed objects in PLA. The purpose of this investigation was to boost toughness and to reduce the production cost of the FFF-printed tensile test samples with the desired part thickness. To remove the need for numerous and idle printing samples, the response surface method (RSM) was used. Statistical analysis was performed to deal with this concern by considering extruder temperature (ET), infill percentage (IP), and layer thickness (LT) as controlled factors. The artificial intelligence method of artificial neural network (ANN) and ANN-genetic algorithm (ANN-GA) were further developed to estimate the toughness, part thickness, and production-cost-dependent variables. Results were evaluated by correlation coefficient and RMSE values. According to the modeling results, ANN-GA as a hybrid machine learning (ML) technique could enhance the accuracy of modeling by about 7.5, 11.5, and 4.5% for toughness, part thickness, and production cost, respectively, in comparison with those for the single ANN method. On the other hand, the optimization results confirm that the optimized specimen is cost-effective and able to comparatively undergo deformation, which enables the usability of printed PLA objects. KW - 3D-Druck KW - Polymere KW - Maschinelles Lernen KW - 3D printing KW - machine learning KW - fused filament fabrication KW - OA-Publikationsfonds2021 Y1 - 2021 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:gbv:wim2-20220110-45518 UR - https://www.mdpi.com/2073-4360/13/19/3219 VL - 2021 IS - Volume 13, issue 19, article 3219 SP - 1 EP - 21 PB - MDPI CY - Basel ER - TY - JOUR A1 - Mehling, Simon A1 - Schnabel, Tobias A1 - Londong, Jörg T1 - Photocatalytic ozonation in an immersion rotary body reactor for the removal of micro-pollutants from the effluent of wastewater treatment plants JF - Water Science & Technology N2 - Carrier-bound titanium dioxide catalysts were used in a photocatalytic ozonation reactor for the degradation of micro-pollutants in real wastewater. A photocatalytic immersion rotary body reactor with a 36-cm disk diameter was used, and was irradiated using UV-A light-emitting diodes. The rotating disks were covered with catalysts based on stainless steel grids coated with titanium dioxide. The dosing of ozone was carried out through the liquid phase via an external enrichment and a supply system transverse to the flow direction. The influence of irradiation power and ozone dose on the degradation rate for photocatalytic ozonation was investigated. In addition, the performance of the individual processes photocatalysis and ozonation were studied. The degradation kinetics of the parent compounds were determined using liquid chromatography tandem mass spectrometry. First-order kinetics were determined for photocatalysis and photocatalytic ozonation. A maximum reaction rate of the reactor was determined, which could be achieved by both photocatalysis and photocatalytic ozonation. At a dosage of 0.4 mg /mg DOC, the maximum reaction rate could be achieved using 75% of the irradiation power used for sole photocatalysis, allowing increases in the energetic efficiency of photocatalytic wastewater treatment processes. The process of photocatalytic ozonation is suitable to remove a wide spectrum of micro-pollutants from wastewater. KW - Abwasserreinigung KW - Fotokatalyse KW - Mikroverunreinigungen KW - anthropogenic micro-pollutants KW - photocatalysis KW - photocatalytic ozonation KW - wastewater treatment KW - titan dioxide Y1 - 2021 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:gbv:wim2-20220209-45865 UR - https://iwaponline.com/wst/article/85/1/535/85800/Photocatalytic-ozonation-in-an-immersion-rotary VL - 2022 IS - volume 85, issue 1 SP - 535 EP - 548 PB - IWA Publishing CY - London ER - TY - THES A1 - Mauludin, Luthfi Muhammad T1 - Computational Modeling of Fracture in Encapsulation-Based Self-Healing Concrete Using Cohesive Elements N2 - Encapsulation-based self-healing concrete has received a lot of attention nowadays in civil engineering field. These capsules are embedded in the cementitious matrix during concrete mixing. When the cracks appear, the embedded capsules which are placed along the path of incoming crack are fractured and then release of healing agents in the vicinity of damage. The materials of capsules need to be designed in a way that they should be able to break with small deformation, so the internal fluid can be released to seal the crack. This study focuses on computational modeling of fracture in encapsulation-based selfhealing concrete. The numerical model of 2D and 3D with randomly packed aggreates and capsules have been developed to analyze fracture mechanism that plays a significant role in the fracture probability of capsules and consequently the self-healing process. The capsules are assumed to be made of Poly Methyl Methacrylate (PMMA) and the potential cracks are represented by pre-inserted cohesive elements with tension and shear softening laws along the element boundaries of the mortar matrix, aggregates, capsules, and at the interfaces between these phases. The effects of volume fraction, core-wall thickness ratio, and mismatch fracture properties of capsules on the load carrying capacity of self-healing concrete and fracture probability of the capsules are investigated. The output of this study will become valuable tool to assist not only the experimentalists but also the manufacturers in designing an appropriate capsule material for self-healing concrete. KW - beton KW - Bruch KW - self healing concrete KW - cohesive elements KW - Fracture KW - Fracture Computational Model Y1 - 2021 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:gbv:wim2-20211008-45204 ER - TY - GEN A1 - Lösel, Joy-Fabienne T1 - Fungal Future – Der Zukunft gewachsen N2 - Die Auswirkungen der durch den Kapitalismus befeuerten Umweltzerstörung werden immer deutlicher erkennbar. Unsere Gesellschaft ist nun damit konfrontiert, dass ihre kulturelle Identität, aber auch ihr Wohlstand sowohl eng mit Konsum und Wirtschaftswachstum als auch mit der Gesundheit der Natur verbunden sind. Es scheint ein geeigneter Moment, um die Perspektive zu wechseln und einer neuen Form des Wachstums eine Chance zu geben. Pilze sind eine von der Region unabhängige, natürlich vorkommende Ressource, die lokal angebaut und verarbeitet werden kann, ohne die Umwelt zu belasten. Pilze sind klimafreundlich, müllvermeidend und in bestehende natürliche Kreisläufe inkludierbar. Kurzum, Pilze sind cool, doch das wissen nicht Viele. Das sollte sich ändern. Mit Myzelwachstum gegen das Wachstumsparadigma. T3 - LUCIA Open Paper - 5 KW - Pilze KW - Nachhaltigkeit Y1 - 2021 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:gbv:wim2-20210603-44408 VL - 2021 PB - Lucia Verlag CY - Weimar ER - TY - JOUR A1 - Londong, Jörg A1 - Barth, Marcus A1 - Söbke, Heinrich T1 - Modeling and Simulation of Source Separation in Sanitation Systems for Reducing Emissions of Antimicrobial Resistances JF - Water N2 - Antimicrobial resistance (AMR) is identified by the World Health Organization (WHO) as one of the top ten threats to public health worldwide. In addition to public health, AMR also poses a major threat to food security and economic development. Current sanitation systems contribute to the emergence and spread of AMR and lack effective AMR mitigation measures. This study assesses source separation of blackwater as a mitigation measure against AMR. A source-separation-modified combined sanitation system with separate collection of blackwater and graywater is conceptually described. Measures taken at the source, such as the separate collection and discharge of material flows, were not considered so far on a load balance basis, i.e., they have not yet been evaluated for their effectiveness. The sanitation system described is compared with a combined system and a separate system regarding AMR emissions by means of simulation. AMR is represented in the simulation model by one proxy parameter each for antibiotics (sulfamethoxa-zole), antibiotic-resistant bacteria (extended-spectrum beta-lactamase E. Coli), and antibiotic re-sistance genes (blaTEM). The simulation results suggest that the source-separation-based sanitation system reduces emissions of antibiotic-resistant bacteria and antibiotic resistance genes into the aquatic environment by more than six logarithm steps compared to combined systems. Sulfa-methoxazole emissions can be reduced by 75.5% by keeping blackwater separate from graywater and treating it sufficiently. In summary, sanitation systems incorporating source separation are, to date, among the most effective means of preventing the emission of AMR into the aquatic envi-ronment. KW - Abwasser KW - Ressourcen KW - microbial resistances KW - antimicrobial resistance genes KW - source separation KW - resource-oriented sanitation KW - UASB KW - OA-Publikationsfonds2021 Y1 - 2021 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:gbv:wim2-20211202-45338 UR - www.mdpi.com/2073-4441/13/23/3342 VL - 2021 IS - Volume 13, issue 23, article 3342 SP - 1 EP - 19 PB - MDPI CY - Basel ER - TY - THES A1 - List, Eik T1 - Design, Analysis, and Implementation of Symmetric-key (Authenticated) Ciphers N2 - Modern cryptography has become an often ubiquitous but essential part of our daily lives. Protocols for secure authentication and encryption protect our communication with various digital services, from private messaging, online shopping, to bank transactions or exchanging sensitive information. Those high-level protocols can naturally be only as secure as the authentication or encryption schemes underneath. Moreover, on a more detailed level, those schemes can also at best inherit the security of their underlying primitives. While widespread standards in modern symmetric-key cryptography, such as the Advanced Encryption Standard (AES), have shown to resist analysis until now, closer analysis and design of related primitives can deepen our understanding. The present thesis consists of two parts that portray six contributions: The first part considers block-cipher cryptanalysis of the round-reduced AES, the AES-based tweakable block cipher Kiasu-BC, and TNT. The second part studies the design, analysis, and implementation of provably secure authenticated encryption schemes. In general, cryptanalysis aims at finding distinguishable properties in the output distribution. Block ciphers are a core primitive of symmetric-key cryptography which are useful for the construction of various higher-level schemes, ranging from authentication, encryption, authenticated encryption up to integrity protection. Therefore, their analysis is crucial to secure cryptographic schemes at their lowest level. With rare exceptions, block-cipher cryptanalysis employs a systematic strategy of investigating known attack techniques. Modern proposals are expected to be evaluated against these techniques. The considerable effort for evaluation, however, demands efforts not only from the designers but also from external sources. The Advanced Encryption Standard (AES) is one of the most widespread block ciphers nowadays. Therefore, it is naturally an interesting target for further analysis. Tweakable block ciphers augment the usual inputs of a secret key and a public plaintext by an additional public input called tweak. Among various proposals through the previous decade, this thesis identifies Kiasu-BC as a noteworthy attempt to construct a tweakable block cipher that is very close to the AES. Hence, its analysis intertwines closely with that of the AES and illustrates the impact of the tweak on its security best. Moreover, it revisits a generic tweakable block cipher Tweak-and-Tweak (TNT) and its instantiation based on the round-reduced AES. The first part investigates the security of the AES against several forms of differential cryptanalysis, developing distinguishers on four to six (out of ten) rounds of AES. For Kiasu-BC, it exploits the additional freedom in the tweak to develop two forms of differential-based attacks: rectangles and impossible differentials. The results on Kiasu-BC consider an additional round compared to attacks on the (untweaked) AES. The authors of TNT had provided an initial security analysis that still left a gap between provable guarantees and attacks. Our analysis conducts a considerable step towards closing this gap. For TNT-AES - an instantiation of TNT built upon the AES round function - this thesis further shows how to transform our distinguisher into a key-recovery attack. Many applications require the simultaneous authentication and encryption of transmitted data. Authenticated encryption (AE) schemes provide both properties. Modern AE schemes usually demand a unique public input called nonce that must not repeat. Though, this requirement cannot always be guaranteed in practice. As part of a remedy, misuse-resistant and robust AE tries to reduce the impact of occasional misuses. However, robust AE considers not only the potential reuse of nonces. Common authenticated encryption also demanded that the entire ciphertext would have to be buffered until the authentication tag has been successfully verified. In practice, this approach is difficult to ensure since the setting may lack the resources for buffering the messages. Moreover, robustness guarantees in the case of misuse are valuable features. The second part of this thesis proposes three authenticated encryption schemes: RIV, SIV-x, and DCT. RIV is robust against nonce misuse and the release of unverified plaintexts. Both SIV-x and DCT provide high security independent from nonce repetitions. As the core under SIV-x, this thesis revisits the proof of a highly secure parallel MAC, PMAC-x, revises its details, and proposes SIV-x as a highly secure authenticated encryption scheme. Finally, DCT is a generic approach to have n-bit secure deterministic AE but without the need of expanding the ciphertext-tag string by more than n bits more than the plaintext. From its first part, this thesis aims to extend the understanding of the (1) cryptanalysis of round-reduced AES, as well as the understanding of (2) AES-like tweakable block ciphers. From its second part, it demonstrates how to simply extend known approaches for (3) robust nonce-based as well as (4) highly secure deterministic authenticated encryption. N2 - Die moderne Kryptographie hat sich zu einem oft unsichtbaren aber essentiellen Teil unserer alltäglichen Kommunikation entwickelt. Protokolle für sichere Authentisierung und Verschlüsselung schützen uns als Gesellschaft in einer Vielzahl von Lebensbereichen, sei es in Nachrichten oder Online-Einkäufen, bis hin zum Schutz von Banktransaktionen oder behördlicher Kommunikation. In den meisten Fällen ist dabei die Sicherstellung von Authentizität und Verschlüsselung von entscheidender Bedeutung. Wie eine Kette ihre Stärke aus den einzelnen Gliedern bezieht, kann jedes kryptographisches Protokoll jedoch nur so sicher sein wie seine darunterliegenden Verfahren und Primitive. Mit den offenen Nominierungswettbewerben haben sich heutige Standards wie zum Beispiel der Advanced Encryption Standard (AES) für Blockchiffren oder der Galois/Counter Mode für authentisierte Verschlüsselung etabliert. Zudem haben sie durch vergangenen zwei Jahrzehnte an Analyse durch die kryptographische Forschergemeinschaft ein hohes Maß an Vertrauen erhalten. Insbesondere in der symmetrischen Kryptographie, die hohen Wert auf Effizienz der Verfahren legt, werden vorwiegend systematische Analysetechniken eingesetzt. Darum ist der Prozess der Verständnisentwicklung und -gewinnung nie abgeschlossen, sondern Bedarf neuer Blickwinkel und Ideen. Als die Kernkomponenten der täglichen Internetkommunikation sind dabei Blockchiffren und Verfahren zur authentisierten Verschlüsselung dabei von besonderem Interesse. Diese Dissertation gliedert sich in zwei Hauptteile die insgesamt sechs Beiträge beinhalten. Der erste Teil ist der Analyse von AES-basierten (tweakable) Blockchiffren gewidmet. Der zweite Teil stellt neue Konstruktionen für robuste authentisierte Verschlüsselung mit hohen Sicherheitsgarantien vor. Die Kryptanalyse versucht nicht-ideale Eigenschaften in den Ausgaben kryptographischer Systeme zu finden. Blockchiffren als wichtige Grundbausteine der symmetrischen Kryptographie sind hierbei von besonderem Interesse, da sie die Grundlage für die Konstruktion sicherer Verfahren für Authentisierung oder Verschlüsselung darstellen. Diese wiederum schützen in Protokollen in einer Vielzahl von Anwendungen uns in unserem Alltag. Die Analyse von Blockchiffren als Grundoperationen ist daher essentiell um die Sicherheit darauf aufbauender Verfahren verstehen zu können. Der AES ist wahrscheinlich die derzeit am weitesten verbreitete moderne Blockchiffre, was ihn allein bereits zum hochinteressanten Studienobjekt macht. Tweakable Blockchiffren ergänzen ihre klassischen Vorbilder um einen zusätzlichen öffentlichen Input, den Tweak, was insbesondere in der jüngeren Vergangenheit zu effizienteren oder sichereren Verfahren geführt hat. AES-basierte Konstruktionen versuchen von der Vielzahl der existierenden bekannten Eigenschaften des AES und seiner Effizienz zu profitieren. Die Rolle des Tweaks für die Sicherheit ist allerdings nicht völlig verstanden. Ihre Analyse ist daher von besonderem Interesse. Der erste Teil dieser Thesis stellt eine neue Sichtweise der differentiellen Analyse von vier bis sechs Runden AES vor. Im weiteren Verlauf betrachtet sie differentielle Angriffe auf Kiasu-BC, eine Tweakable Blockchiffre auf Basis des AES, die versucht, so nah wie möglich am Design des AES zu bleiben. Somit kann ihre Analyse die durch den Tweak hervorgerufenen Unterschiede genauer beleuchten als das bei dedizierten Konstruktion möglich wäre. Abschließend analysiert der erste Teil Tweak-and-Tweak (TNT), eine generische Transformation einer klassischen in eine tweakable Blockchiffre, sowie ihre Instanz TNT-AES. Durch einen besseren Sicherheitsbeweis von TNT schließt sie die Lücke (mit Ausnahme eines logarithmischen Faktors) zwischen ihrer vorher bewiesenen Sicherheit und bekannten Angriffen. Eine Vielzahl von Anwendungen für Authentisierung oder Verschlüsselung benötigen beide Eigenschaften simultan. Darum sind Verfahren für die Authentisierte Verschlüsselung (AE Schemes) aus dem täglichen Gebrauch nicht mehr wegzudenken. Bis vor einigen Jahren waren die Anforderungen an den Gebrauch von AE Schemes allerdings sehr restriktiv: Moderne AE Schemes erfordern in der Regel für jede zu verschlüsselnde Nachricht einen Input der sich nicht wiederholen darf, eine Nonce. Nonces sind allgemein akzeptiert und sinnvoll - ihre Einmaligkeit kann jedoch nicht über alle Anwendungsumgebungen hinweg garantiert werden. Für viele Konstruktionen bedeutet eine Verletzung der Anforderungen allerdings dass keinerlei Sicherheit mehr gewährleistet werden kann. Robuste AE Schemes wurden eingeführt um den Schaden möglichst auch im Fall von Nonce-Wiederholungen Sicherheit zu garantieren. Derartige Verfahren bedenken darüberhinaus auch den Fall, dass ungültige Klartexte unbeabsichtigt nach außen gelangen, was insbesondere in Umgebungen relevant ist, in denen sie nicht bis zur erfolgreichen Verifikation gespeichert werden können. Die vorliegende Arbeit stellt drei blockchiffrenbasierte Verfahren für misuse-resiliente authentisierte Verschlüsselung vor: RIV, SIV-x und DCT. RIV bietet Robustheit gegen Nonce-Wiederholungen wie auch gegen die Fälle in denen Informationen über ungültige Entschlüsselungen nach außen gelangen. SIV-x und DCT bieten sehr hohe Sicherheitsgarantien ohne auf Nonces angewiesen zu sein, jeweils basierend auf tweakable Blockchiffren. Im ersten Teil möchte die vorliegende Arbeit zum Einen das Verständnis der differentiellen Sicherheit des rundenreduzierten AES hin zu Unterscheidungsangriffen mit extrem kleinen, aber dennoch signifikanten Differenzen ergänzen. Zum Anderen erweitert dieser Teil die Analyse AES-ähnlicher Tweakable Blockchiffren. Der zweite Teil ergänzt zum Einen mit RIV das Portfolio robuster authentisierter Verschlüsselungsverfahren und zeigt wie diese effizient implementiert werden können. Zum Anderen zeigt er mit SIV-x und DCT, wie deterministische authentisierte Verschlüsselung mit hohen Sicherheitsanforderungen mit zwei Iterationen von denen nur eine pseudozufällig sein muss realisiert werden können. KW - Kryptologie KW - Cryptography KW - Symmetric-key cryptography KW - Cryptanalysis KW - Provable security KW - Encryption Y1 - 2021 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:gbv:wim2-20211103-45235 ER - TY - JOUR A1 - Legatiuk, Dmitrii A1 - Weisz-Patrault, Daniel T1 - Coupling of Complex Function Theory and Finite Element Method for Crack Propagation Through Energetic Formulation: Conformal Mapping Approach and Reduction to a Riemann–Hilbert Problem JF - Computational Methods and Function Theory N2 - In this paper we present a theoretical background for a coupled analytical–numerical approach to model a crack propagation process in two-dimensional bounded domains. The goal of the coupled analytical–numerical approach is to obtain the correct solution behaviour near the crack tip by help of the analytical solution constructed by using tools of complex function theory and couple it continuously with the finite element solution in the region far from the singularity. In this way, crack propagation could be modelled without using remeshing. Possible directions of crack growth can be calculated through the minimization of the total energy composed of the potential energy and the dissipated energy based on the energy release rate. Within this setting, an analytical solution of a mixed boundary value problem based on complex analysis and conformal mapping techniques is presented in a circular region containing an arbitrary crack path. More precisely, the linear elastic problem is transformed into a Riemann–Hilbert problem in the unit disk for holomorphic functions. Utilising advantages of the analytical solution in the region near the crack tip, the total energy could be evaluated within short computation times for various crack kink angles and lengths leading to a potentially efficient way of computing the minimization procedure. To this end, the paper presents a general strategy of the new coupled approach for crack propagation modelling. Additionally, we also discuss obstacles in the way of practical realisation of this strategy. KW - Angewandte Mathematik KW - Finite-Elemente-Methode KW - Rissausbreitung KW - Modellierung KW - Bruchmechanik KW - fracture mechanics KW - crack propagation KW - coupling KW - energetic approach Y1 - 2021 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:gbv:wim2-20210805-44763 UR - https://link.springer.com/article/10.1007/s40315-021-00403-7 VL - 2021 SP - 1 EP - 23 PB - Springer CY - Heidelberg ER - TY - JOUR A1 - Legatiuk, Dmitrii T1 - Mathematical Modelling by Help of Category Theory: Models and Relations between Them JF - mathematics N2 - The growing complexity of modern practical problems puts high demand on mathematical modelling. Given that various models can be used for modelling one physical phenomenon, the role of model comparison and model choice is becoming particularly important. Methods for model comparison and model choice typically used in practical applications nowadays are computationbased, and thus time consuming and computationally costly. Therefore, it is necessary to develop other approaches to working abstractly, i.e., without computations, with mathematical models. An abstract description of mathematical models can be achieved by the help of abstract mathematics, implying formalisation of models and relations between them. In this paper, a category theory-based approach to mathematical modelling is proposed. In this way, mathematical models are formalised in the language of categories, relations between the models are formally defined and several practically relevant properties are introduced on the level of categories. Finally, an illustrative example is presented, underlying how the category-theory based approach can be used in practice. Further, all constructions presented in this paper are also discussed from a modelling point of view by making explicit the link to concrete modelling scenarios. KW - Kategorientheorie KW - Modellierung KW - Modellierungsmethode KW - OA-Publikationsfonds2021 Y1 - 2021 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:gbv:wim2-20210817-44844 UR - https://www.mdpi.com/2227-7390/9/16/1946?type=check_update&version=1 VL - 2021 IS - volume 9, issue 16, article 1946 PB - MDPI CY - Basel ER - TY - JOUR A1 - Legatiuk, Anastasiia A1 - Gürlebeck, Klaus A1 - Hommel, Angela T1 - Estimates for the discrete fundamental solution of the discrete Laplace operator on a rectangular lattice JF - Mathematical Methods in the Applied Sciences N2 - This paper presents numerical analysis of the discrete fundamental solution of the discrete Laplace operator on a rectangular lattice. Additionally, to provide estimates in interior and exterior domains, two different regularisations of the discrete fundamental solution are considered. Estimates for the absolute difference and lp-estimates are constructed for both regularisations. Thus, this work extends the classical results in the discrete potential theory to the case of a rectangular lattice and serves as a basis for future convergence analysis of the method of discrete potentials on rectangular lattices. KW - diskrete Fourier-Transformation KW - Laplace-Operator KW - discrete fourier transform KW - discrete fundamental solution KW - laplace operator KW - rectangular lattice Y1 - 2021 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:gbv:wim2-20220209-45829 UR - https://onlinelibrary.wiley.com/doi/full/10.1002/mma.7747 VL - 2021 SP - 1 EP - 23 PB - Wiley CY - Chichester ER - TY - JOUR A1 - Lashkar-Ara, Babak A1 - Kalantari, Niloofar A1 - Sheikh Khozani, Zohreh A1 - Mosavi, Amir T1 - Assessing Machine Learning versus a Mathematical Model to Estimate the Transverse Shear Stress Distribution in a Rectangular Channel JF - Mathematics N2 - One of the most important subjects of hydraulic engineering is the reliable estimation of the transverse distribution in the rectangular channel of bed and wall shear stresses. This study makes use of the Tsallis entropy, genetic programming (GP) and adaptive neuro-fuzzy inference system (ANFIS) methods to assess the shear stress distribution (SSD) in the rectangular channel. To evaluate the results of the Tsallis entropy, GP and ANFIS models, laboratory observations were used in which shear stress was measured using an optimized Preston tube. This is then used to measure the SSD in various aspect ratios in the rectangular channel. To investigate the shear stress percentage, 10 data series with a total of 112 different data for were used. The results of the sensitivity analysis show that the most influential parameter for the SSD in smooth rectangular channel is the dimensionless parameter B/H, Where the transverse coordinate is B, and the flow depth is H. With the parameters (b/B), (B/H) for the bed and (z/H), (B/H) for the wall as inputs, the modeling of the GP was better than the other one. Based on the analysis, it can be concluded that the use of GP and ANFIS algorithms is more effective in estimating shear stress in smooth rectangular channels than the Tsallis entropy-based equations. KW - Maschinelles Lernen KW - smooth rectangular channel KW - Tsallis entropy KW - genetic programming KW - artificial intelligence KW - machine learning KW - big data KW - computational hydraulics Y1 - 2021 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:gbv:wim2-20210504-44197 UR - https://www.mdpi.com/2227-7390/9/6/596 VL - 2021 IS - Volume 9, Issue 6, Article 596 PB - MDPI CY - Basel ER - TY - GEN A1 - Königshofen, Max T1 - Mahnmal oder Tanztempel? Das Funkhaus und seine Rolle in der Weimarer Clubkultur N2 - Im Südwesten Weimars befindet sich ein leerstehender Gebäudekomplex, der im Stadtraum heute unter dem Namen Funkhaus und vor allem für studentisch organisierte Partys bekannt ist. Doch das Gebäude entstand ursprünglich nicht als Radiostation, sondern zwischen 1937 und 1944 als Prestigeprojekt des nationalsozialistisch zugespitzten Nietzsche-Kults. Diese Projektarbeit beleuchtet anhand von Archivalien und Expertinneninterviews die Nutzungsgeschichte der ehemaligen »Nietzsche-Gedächtnishalle« und wirft die Frage auf, ob und wie ein solcher NS-Bau als Partylocation genutzt werden kann. T3 - LUCIA Open Paper - 2 KW - Funkhaus KW - Weimar KW - Medien Y1 - 2021 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:gbv:wim2-20210603-44377 VL - 2021 PB - Lucia Verlag CY - Weimar ER - TY - JOUR A1 - Kraus, Matthias A1 - Klaus, Martin A1 - Wittor, Björn T1 - Experimental Analyses on the Resistance of Tapped Blind Holes JF - ce/papers N2 - Bolted connections are commonly used in steel construction. The load-bearing behavior of bolt fittings has extensively been studied in various research activities and the bearing capacity of bolted connections can be assessed well by standard regulations for practical applications. With regard to tensile loading, the nut does not have strong influence on resistances, since the failure occurs in the bolts due to higher material strengths of the nuts. In some applications, so-called “blind holes” are used to connect plated components. In a manner of speaking, the nut is replaced by the “outer” plate with a prefabricated hole and thread, in which the bolt can be screwed and tightened. In such connections, the limit load capacity cannot solely be assessed by the bolt resistance, since the threaded hole in the base material has strong influence on the structural behavior. In this context, the available screw-in depth of the blind hole is of fundamental importance. The German National Annex of EN 1993-1-8 provides information on a necessary depth in order to transfer the full tensile capacity of the bolt. However, some connections do not allow to fabricate such depths. In these cases, the capacity of the connection is unclear and not specified. In this paper, first experiments on corresponding connections with different screw-in depths are presented and compared to limit load capacities according to the standard. KW - Gewinde KW - Bolzen KW - threat KW - bolt KW - tapped blind holes Y1 - 2021 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:gbv:wim2-20220112-45553 UR - https://onlinelibrary.wiley.com/doi/10.1002/cepa.1273 VL - 2021 IS - Volume 4, issue 2-4 SP - 141 EP - 147 PB - Ernst & Sohn, a Wiley brand CY - Berlin ER - TY - JOUR A1 - Kraus, Matthias A1 - Crişan, Nicolae-Andrei A1 - Wittor, Björn T1 - Stability Study of Cantilever-Beams – Numerical Analysis and Analytical Calculation (LTB) JF - ce/papers N2 - According to Eurocode, the computation of bending strength for steel cantilever beams is a straightforward process. The approach is based on an Ayrton-Perry formula adaptation of buckling curves for steel members in compression, which involves the computation of an elastic critical buckling load for considering the instability. NCCI documents offer a simplified formula to determine the critical bending moment for cantilevers beams with symmetric cross-section. Besides the NCCI recommendations, other approaches, e.g. research literature or Finite-Element-Analysis, may be employed to determine critical buckling loads. However, in certain cases they render different results. Present paper summarizes and compares the abovementioned analytical and numerical approaches for determining critical loads and it exemplarily analyses corresponding cantilever beam capacities using numerical approaches based on plastic zones theory (GMNIA). KW - Träger KW - Stahl KW - Biegefestigkeit KW - Finite-Elemente-Methode KW - Stahlträger KW - Knicklast KW - Freiträgerkapazität KW - Eurocode Y1 - 2021 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:gbv:wim2-20220112-45637 UR - https://onlinelibrary.wiley.com/doi/full/10.1002/cepa.1539 VL - 2021 IS - Volume 4, issue 2-4 SP - 2199 EP - 2206 PB - Ernst & Sohn, a Wiley brand CY - Berlin ER - TY - JOUR A1 - Kleiner, Florian A1 - Rößler, Christiane A1 - Vogt, Franziska A1 - Osburg, Andrea A1 - Ludwig, Horst-Michael T1 - Reconstruction of calcium silicate hydrates using multiple 2D and 3D imaging techniques: Light microscopy, μ-CT, SEM, FIB-nT combined with EDX JF - Journal of Microscopy N2 - This study demonstrates the application and combination of multiple imaging techniques [light microscopy, micro-X-ray computer tomography (μ-CT), scanning electron microscopy (SEM) and focussed ion beam – nano-tomography (FIB-nT)] to the analysis of the microstructure of hydrated alite across multiple scales. However, by comparing findings with mercury intrusion porosimetry (MIP), it becomes obvious that the imaged 3D volumes and 2D images do not sufficiently overlap at certain scales to allow a continuous quantification of the pore size distribution (PSD). This can be overcome by improving the resolution and increasing the measured volume. Furthermore, results show that the fibrous morphology of calcium-silicate-hydrates (C-S-H) phases is preserved during FIB-nT. This is a requirement for characterisation of nano-scale porosity. Finally, it was proven that the combination of FIB-nT with energy-dispersive X-ray spectroscopy (EDX) data facilitates the phase segmentation of a 11 × 11 × 7.7 μm3 volume of hydrated alite. KW - Zementklinker KW - Bildsegmentierung KW - Rasterelektronenmikroskopie KW - Computertomographie KW - tomography KW - focussed ion beam KW - cement microstructure KW - micro-CT Y1 - 2021 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:gbv:wim2-20220106-45458 UR - https://onlinelibrary.wiley.com/doi/10.1111/jmi.13081 VL - 2021 SP - 1 EP - 6 PB - John Wiley & Sons Ltd CY - Oxford ER - TY - CHAP A1 - Kleiner, Florian A1 - Rößler, Christiane T1 - Utilizing Modern FIB/SEM Technology and EDS for 3D Imaging of Hydrated Alite and its Pore Space T2 - ERICA-CASH II Final Converence N2 - The exploration of cementitious materials using scanning electron microscopes (SEM) is mainly done using fractured or polished surfaces. This leads to high-resolution 2D-images that can be combined using EDX and EBSD to unveil details of the microstructure and composition of materials. Nevertheless, this does not provide a quantitative insight into the three-dimensional fine structure of for example C-S-H phases. The focused ion beam (FIB) technology can cut a block of material in thin layers of less than 10 nm. This gives us a volume of 1000 μm³ with a voxel resolution of down to 4 x 4 x 10 nm³. The results can be combined with simultaneously acquired EDX data to improve image segmentation. Results of the investigation demonstrate that it is possible to obtain close-to-native 3D-visualisation of the spatial distribution of unreacted C3S, C-S-H and CH. Additionally, an optimized preparation method allows us to quantify the fine structure of C-S-H phases (length, aspect ratio, …) and the pore space. KW - Rasterelektronenmikroskop KW - Alit KW - SEM KW - Focussed Ion Beam KW - EDX KW - energy dispersive X-ray spectroscopy KW - alite Y1 - 2021 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:gbv:wim2-20210702-44555 ER - TY - JOUR A1 - Kleiner, Florian T1 - Optimization and semi-automatic evaluation of a frosting process for a soda lime silicate glass based on phosphoric acid JF - International Journal of Applied Glass Science N2 - Chemical glass frosting processes are widely used to create visual attractive glass surfaces. A commonly used frosting bath mainly contains ammonium bifluoride (NH4HF2) mixed with hydrochloric acid (HCl). The frosting process consists of several baths. Firstly, the preliminary bath to clean the object. Secondly, the frosting bath which etches the rough light scattering structure into the glass surface. Finally, the washing baths to clean the frosted object. This is where the constituents of the preceding steps accumulate and have to be filtered from the sewage. In the present contribution, phosphoric acid (H3PO4) was used as a substitute for HCl to reduce the amount of ammonium (NH4+) and chloride (Cl−) dissolved in the waste water. In combination with magnesium carbonate (MgCO3), it allows the precipitation of ammonium within the sewage as ammonium magnesium phosphate (MgNH4PO4). However, a trivial replacement of HCl by H3PO4 within the frosting process causes extensive frosting errors, such as inhomogeneous size distributions of the structures or domains that are not fully covered by these structures. By modifying the preliminary bath composition, it was possible to improve the frosting result considerably. To determine the optimal composition of the preliminary bath, a semi-automatic evaluation method has been developed. This method renders the objective comparison of the resulting surface quality possible. KW - Silicatglas KW - Mattieren KW - Ätzen KW - automated quality control KW - etching KW - glass frosting KW - phosphoric acid Y1 - 2021 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:gbv:wim2-20210701-44548 UR - https://ceramics.onlinelibrary.wiley.com/doi/10.1111/ijag.15866 SP - 1 EP - 8 PB - John Wiley & Sons ER - TY - INPR A1 - Khosravi, Khabat A1 - Sheikh Khozani, Zohreh A1 - Mao, Luka T1 - A comparison between advanced hybrid machine learning algorithms and empirical equations applied to abutment scour depth prediction N2 - Complex vortex flow patterns around bridge piers, especially during floods, cause scour process that can result in the failure of foundations. Abutment scour is a complex three-dimensional phenomenon that is difficult to predict especially with traditional formulas obtained using empirical approaches such as regressions. This paper presents a test of a standalone Kstar model with five novel hybrid algorithm of bagging (BA-Kstar), dagging (DA-Kstar), random committee (RC-Kstar), random subspace (RS-Kstar), and weighted instance handler wrapper (WIHWKstar) to predict scour depth (ds) for clear water condition. The dataset consists of 99 scour depth data from flume experiments (Dey and Barbhuiya, 2005) using abutment shapes such as vertical, semicircular and 45◦ wing. Four dimensionless parameter of relative flow depth (h/l), excess abutment Froude number (Fe), relative sediment size (d50/l) and relative submergence (d50/h) were considered for the prediction of relative scour depth (ds/l). A portion of the dataset was used for the calibration (70%), and the remaining used for model validation. Pearson correlation coefficients helped deciding relevance of the input parameters combination and finally four different combinations of input parameters were used. The performance of the models was assessed visually and with quantitative metrics. Overall, the best input combination for vertical abutment shape is the combination of Fe, d50/l and h/l, while for semicircular and 45◦ wing the combination of the Fe and d50/l is the most effective input parameter combination. Our results show that incorporating Fe, d50/l and h/l lead to higher performance while involving d50/h reduced the models prediction power for vertical abutment shape and for semicircular and 45◦ wing involving h/l and d50/h lead to more error. The WIHW-Kstar provided the highest performance in scour depth prediction around vertical abutment shape while RC-Kstar model outperform of other models for scour depth prediction around semicircular and 45◦ wing. KW - maschinelles Lernen Y1 - 2021 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:gbv:wim2-20210311-43889 N1 - This is the pre-peer reviewed version of the following article: https://www.sciencedirect.com/science/article/abs/pii/S0022169421001475?via%3Dihub ; https://doi.org/10.1016/j.jhydrol.2021.126100 ER - TY - INPR A1 - Khosravi, Khabat A1 - Sheikh Khozani, Zohreh A1 - Cooper, James R. T1 - Predicting stable gravel-bed river hydraulic geometry: A test of novel, advanced, hybrid data mining algorithms N2 - Accurate prediction of stable alluvial hydraulic geometry, in which erosion and sedimentation are in equilibrium, is one of the most difficult but critical topics in the field of river engineering. Data mining algorithms have been gaining more attention in this field due to their high performance and flexibility. However, an understanding of the potential for these algorithms to provide fast, cheap, and accurate predictions of hydraulic geometry is lacking. This study provides the first quantification of this potential. Using at-a-station field data, predictions of flow depth, water-surface width and longitudinal water surface slope are made using three standalone data mining techniques -, Instance-based Learning (IBK), KStar, Locally Weighted Learning (LWL) - along with four types of novel hybrid algorithms in which the standalone models are trained with Vote, Attribute Selected Classifier (ASC), Regression by Discretization (RBD), and Cross-validation Parameter Selection (CVPS) algorithms (Vote-IBK, Vote-Kstar, Vote-LWL, ASC-IBK, ASC-Kstar, ASC-LWL, RBD-IBK, RBD-Kstar, RBD-LWL, CVPSIBK, CVPS-Kstar, CVPS-LWL). Through a comparison of their predictive performance and a sensitivity analysis of the driving variables, the results reveal: (1) Shield stress was the most effective parameter in the prediction of all geometry dimensions; (2) hybrid models had a higher prediction power than standalone data mining models, empirical equations and traditional machine learning algorithms; (3) Vote-Kstar model had the highest performance in predicting depth and width, and ASC-Kstar in estimating slope, each providing very good prediction performance. Through these algorithms, the hydraulic geometry of any river can potentially be predicted accurately and with ease using just a few, readily available flow and channel parameters. Thus, the results reveal that these models have great potential for use in stable channel design in data poor catchments, especially in developing nations where technical modelling skills and understanding of the hydraulic and sediment processes occurring in the river system may be lacking. KW - Maschinelles Lernen KW - Künstliche Intelligenz KW - Data Mining KW - Hydraulic geometry KW - Gravel-bed rivers Y1 - 2021 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:gbv:wim2-20211004-44998 N1 - This is the pre-peer reviewed version of the following article: https://www.sciencedirect.com/science/article/abs/pii/S1364815221002085 ; https://doi.org/10.1016/j.envsoft.2021.105165 VL - 2021 ER - TY - THES A1 - Khademi Zahedi, Reza T1 - Stress Distribution in Buried Defective PE Pipes and Crack Propagation in Nanosheets N2 - Buried PE pipelines are the main choice for transporting hazardous hydrocarbon fluids and are used in urban gas distribution networks. Molecular dynamics (MD) simulations used to investigate material behavior at nanoscale. KW - Gasleitung KW - gas pipes KW - Riss KW - Defekt KW - defects KW - nanosheets KW - crack KW - maximum stress Y1 - 2021 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:gbv:wim2-20210803-44814 ER - TY - JOUR A1 - Jiang, Mingze A1 - Rößler, Christiane A1 - Wellmann, Eva A1 - Klaver, Jop A1 - Kleiner, Florian A1 - Schmatz, Joyce T1 - Workflow for high-resolution phase segmentation of cement clinker fromcombined BSE image and EDX spectral data JF - Journal of Microscopy N2 - Burning of clinker is the most influencing step of cement quality during the production process. Appropriate characterisation for quality control and decision-making is therefore the critical point to maintain a stable production but also for the development of alternative cements. Scanning electron microscopy (SEM) in combination with energy dispersive X-ray spectroscopy (EDX) delivers spatially resolved phase and chemical information for cement clinker. This data can be used to quantify phase fractions and chemical composition of identified phases. The contribution aims to provide an overview of phase fraction quantification by semi-automatic phase segmentation using high-resolution backscattered electron (BSE) images and lower-resolved EDX element maps. Therefore, a tool for image analysis was developed that uses state-of-the-art algorithms for pixel-wise image segmentation and labelling in combination with a decision tree that allows searching for specific clinker phases. Results show that this tool can be applied to segment sub-micron scale clinker phases and to get a quantification of all phase fractions. In addition, statistical evaluation of the data is implemented within the tool to reveal whether the imaged area is representative for all clinker phases. KW - Zementklinker KW - Bildsegmentierung KW - Rasterelektronenmikroskopie KW - cement clinker KW - image segmentation KW - EDX KW - superpixel Y1 - 2021 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:gbv:wim2-20211215-45449 UR - https://onlinelibrary.wiley.com/doi/epdf/10.1111/jmi.13072 VL - 2021 SP - 1 EP - 7 PB - Wiley-Blackwell CY - Oxford ER - TY - JOUR A1 - Ibanez, Stalin A1 - Kraus, Matthias T1 - A Numerical Approach for Plastic Cross Cross-Sectional Analyses of Steel Members JF - ce/papers N2 - Global structural analyses in civil engineering are usually performed considering linear-elastic material behavior. However, for steel structures, a certain degree of plasticization depending on the member classification may be considered. Corresponding plastic analyses taking material nonlinearities into account are effectively realized using numerical methods. Frequently applied finite elements of two and three-dimensional models evaluate the plasticity at defined nodes using a yield surface, i.e. by a yield condition, hardening rule, and flow rule. Corresponding calculations are connected to a large numerical as well as time-consuming effort and they do not rely on the theoretical background of beam theory, to which the regulations of standards mainly correspond. For that reason, methods using beam elements (one-dimensional) combined with cross-sectional analyses are commonly applied for steel members in terms of plastic zones theories. In these approaches, plasticization is in general assessed by means of axial stress only. In this paper, more precise numerical representation of the combined stress states, i.e. axial and shear stresses, is presented and results of the proposed approach are validated and discussed. KW - Stahlkonstruktion KW - Plastizität KW - Strukturanalyse KW - Stahlbauteil KW - Axialspannung KW - Finite-Elemente-Methode Y1 - 2021 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:gbv:wim2-20220112-45622 UR - https://onlinelibrary.wiley.com/doi/full/10.1002/cepa.1527 VL - 2021 IS - Volume 4, issue 2-4 SP - 2098 EP - 2106 PB - Ernst & Sohn, a Wiley brand CY - Berlin ER - TY - THES A1 - Hörold, Stefan T1 - Leistungsbezogene Musterjahresganglinien für den Straßenbetriebsdienst N2 - In den letzten Jahrzehnten unterlag der Straßenbetriebsdienst tiefgreifenden Veränderungen. Diese Veränderungen schließt auch die betriebliche Steuerungsphilosophie ein, um eine planungsrationale und ökonomische Gestaltung des Straßenbetriebsdienstes zu unterstützen. Dabei erfolgt eine verbindliche Vorgabe der Leistungsinhalte und -umfänge und ermöglicht eine Budgetierung für das vorgesehene Jahresarbeitsprogramm. Ziel der Untersuchung ist die Entwicklung eines Modells für die Ermittlung von leistungsbezogenen Musterjahresganglinien zur Unterstützung der Jahresarbeitsplanung. Dafür lagen für jede Leistung des Leistungsbereiches „Grünpflege“ jeweils 260 einzelne Jahresganglinien vor. Im Ergebnis der Untersuchung wird die leistungsbezogene Musterjahresganglinie in vier Schritten ermittelt. Im ersten Schritt erfolgt die Prüfung der Datenqualität; im zweiten Schritt eine Korrelationsanalyse; im dritten Schritt die fachliche Überprüfung der Leistungsausprägung und im vierten Schritt die Ermittlung der leistungsbezogenen Musterjahresganglinie aus den verbliebenen leistungsbezogenen Jahresganglinien. T3 - Schriften der Professur Baubetrieb und Bauverfahren - 40 KW - Straßenbetriebsdienst KW - Budgetierung KW - Arbeitsplanung KW - Ergebnisorientierte Steuerung KW - Musterjahresganglinien KW - Jahresarbeitsplanung Y1 - 2021 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:gbv:wim2-20210830-44910 ER - TY - JOUR A1 - Harirchian, Ehsan A1 - Kumari, Vandana A1 - Jadhav, Kirti A1 - Rasulzade, Shahla A1 - Lahmer, Tom A1 - Raj Das, Rohan T1 - A Synthesized Study Based on Machine Learning Approaches for Rapid Classifying Earthquake Damage Grades to RC Buildings JF - Applied Sciences N2 - A vast number of existing buildings were constructed before the development and enforcement of seismic design codes, which run into the risk of being severely damaged under the action of seismic excitations. This poses not only a threat to the life of people but also affects the socio-economic stability in the affected area. Therefore, it is necessary to assess such buildings’ present vulnerability to make an educated decision regarding risk mitigation by seismic strengthening techniques such as retrofitting. However, it is economically and timely manner not feasible to inspect, repair, and augment every old building on an urban scale. As a result, a reliable rapid screening methods, namely Rapid Visual Screening (RVS), have garnered increasing interest among researchers and decision-makers alike. In this study, the effectiveness of five different Machine Learning (ML) techniques in vulnerability prediction applications have been investigated. The damage data of four different earthquakes from Ecuador, Haiti, Nepal, and South Korea, have been utilized to train and test the developed models. Eight performance modifiers have been implemented as variables with a supervised ML. The investigations on this paper illustrate that the assessed vulnerability classes by ML techniques were very close to the actual damage levels observed in the buildings. KW - Maschinelles Lernen KW - Neuronales Netz KW - Machine learning KW - Building safety assessment KW - artificial neural networks KW - supervised learning KW - damaged buildings KW - rapid classification KW - OA-Publikationsfonds2021 Y1 - 2021 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:gbv:wim2-20210818-44853 UR - https://www.mdpi.com/2076-3417/11/16/7540 VL - 2021 IS - Volume 11, issue 16, article 7540 SP - 1 EP - 33 PB - MDPI CY - Basel ER - TY - THES A1 - Harirchian, Ehsan T1 - Improved Rapid Assessment of Earthquake Hazard Safety of Existing Buildings Using a Hierarchical Type-2 Fuzzy Logic Model N2 - Although it is impractical to avert subsequent natural disasters, advances in simulation science and seismological studies make it possible to lessen the catastrophic damage. There currently exists in many urban areas a large number of structures, which are prone to damage by earthquakes. These were constructed without the guidance of a national seismic code, either before it existed or before it was enforced. For instance, in Istanbul, Turkey, as a high seismic area, around 90% of buildings are substandard, which can be generalized into other earthquakeprone regions in Turkey. The reliability of this building stock resulting from earthquake-induced collapse is currently uncertain. Nonetheless, it is also not feasible to perform a detailed seismic vulnerability analysis on each building as a solution to the scenario, as it will be too complicated and expensive. This indicates the necessity of a reliable, rapid, and computationally easy method for seismic vulnerability assessment, commonly known as Rapid Visual Screening (RVS). In RVS methodology, an observational survey of buildings is performed, and according to the data collected during the visual inspection, a structural score is calculated without performing any structural calculations to determine the expected damage of a building and whether the building needs detailed assessment. Although this method might save time and resources due to the subjective/qualitative judgments of experts who performed the inspection, the evaluation process is dominated by vagueness and uncertainties, where the vagueness can be handled adequately through the fuzzy set theory but do not cover all sort of uncertainties due to its crisp membership functions. In this study, a novel method of rapid visual hazard safety assessment of buildings against earthquake is introduced in which an interval type-2 fuzzy logic system (IT2FLS) is used to cover uncertainties. In addition, the proposed method provides the possibility to evaluate the earthquake risk of the building by considering factors related to the building importance and exposure. A smartphone app prototype of the method has been introduced. For validation of the proposed method, two case studies have been selected, and the result of the analysis presents the robust efficiency of the proposed method. KW - Fuzzy-Logik KW - Erdbebensicherheit KW - Fuzzy logic KW - RC Buildings KW - Rapid Visual Assessment KW - Seismic Vulnerability KW - Uncertainty Y1 - 2021 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:gbv:wim2-20210326-43963 ER - TY - THES A1 - Gründer, Anika T1 - Denkmalzugänge zwischen Abgrenzen, Genießen, Erinnern und Teilhaben BT - Eine Ethnografie über Schloss Bedheim und seine Besucher N2 - Die interdisziplinäre Dissertationsschrift lässt sich im Horizont internationaler Forschungen zu Denkmalwerten, neuer Ansätze in der Kultur- und Wissensvermittlung rund um Baudenkmale sowie künstlerisch- ethnographischem Forschen an und mit Denkmalen verorten. Der erste Teil der Arbeit widmet sich Denkmalen und der Denkmalpflege im Kontext künstlerischer und sozialwissenschaftlicher Allianzen. Ausgangspunkt ist die Feststellung, dass die Denkmalpflege zwar sehr vieles über Denkmale weiß, aber kaum etwas über deren Rezeption beim breiten Publikum. Im Mittelpunkt steht die Frage, wie hier Praktiken der bildenden Kunst und Arbeitsweisen der Kulturanthropologie die Disziplin der Denkmalpflege bereichern können, oder sogar müssen. Den zweiten Teil bildet eine empirische Studie, in der die populäre Wahrnehmung von Denkmalen qualitativ erforscht wird. Das Schloss und Rittergut Bedheim im südlichen ländlichen Thüringen dient dabei als konkreter Untersuchungsort. Reaktionen von Besucherinnen und Besuchern werden mit Hilfe von drei künstlerischen Eingriffen angeregt und diese dann ethnographisch-offen dokumentiert und ausgewertet. Auf dieser Basis werden Zugänge zum Denkmal ermittelt. Während die meisten BesucherInnen das Denkmal als „Arbeit“ wahrnehmen, geraten einige ins „Träumen“ oder „Erinnern“, man „genießt“ das Ensemble als authentische und ästhetische Ressource, oder findet Zugang über das spontane „Erklären“ baukonstruktiver oder baulicher Situationen. Für andere bedeutet der Besuch die „Teilhabe“ an einem Prozess. Schloss Bedheim wird als Ort stetiger Veränderung geschätzt. In der Wahrnehmung der BesucherInnen verquicken sich Aspekte des Bewunderns mit solchen des Abgrenzens. Die eigene Alltagswelt und das eigene Zuhause bilden hierbei Bezugspunkte. Schloss Bedheim wird auf diese Weise zum Imaginationsraum, zur Energietankstelle und zur gern besuchten Problemwelt. Die Ergebnisse der Arbeit liegen in zwei Erkenntnisfeldern: Auf einer methodischen Ebene zeigt sie, wie in der Denkmalpflege vertiefte Fachlichkeit mit einer tatsächlichen Kontaktaufnahme mit dem Publikum verbunden werden kann und damit soziale Gefüge an Baudenkmalen qualitativ ermittelt werden können. Ebenso wird deutlich, dass künstlerische Eingriffe Auslöser von Gesprächen sind, als Kontaktflächen zur Alltagswelt dienen und so zu einer vielfältigen Auseinandersetzung mit Denkmalen führen. Auf einer inhaltlichen Ebene liefert die Arbeit Erkenntnisse zu Wahrnehmungsweisen von Denkmalen. Neben den erwähnten Zugängen, wird die Existenz und Bedeutung einer regional vernetzten Wahrnehmung von Denkmalen aufgedeckt. Des Weiteren zeigen die Ergebnisse, dass das Öffnen von Baudenkmalen als und im Prozess ungenutzte Potentiale birgt und es wird angeregt, dies in zukünftigen denkmalpflegerischen Konzepten eine größere Rolle spielen zu lassen. Die Vision eines „Kompendiums der Zugänge“ wird entwickelt, mit dessen Hilfe sich ein enormes Wissen über Rollen und Bedeutungen die Baudenkmale in unserer Gesellschaft spielen, sammeln ließe. KW - Denkmalpflege KW - Ethnologie KW - Kunst KW - Teilnehmende Beobachtung KW - Schloss KW - Ethnografie KW - Denkmalwerte KW - Kunst-Denkmal-Kollaborationen KW - Vermittlung KW - Ländlicher Raum Y1 - 2021 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:gbv:wim2-20210628-44569 ER - TY - THES A1 - Goswami, Somdatta T1 - Phase field modeling of fracture with isogeometric analysis and machine learning methods N2 - This thesis presents the advances and applications of phase field modeling in fracture analysis. In this approach, the sharp crack surface topology in a solid is approximated by a diffusive crack zone governed by a scalar auxiliary variable. The uniqueness of phase field modeling is that the crack paths are automatically determined as part of the solution and no interface tracking is required. The damage parameter varies continuously over the domain. But this flexibility comes with associated difficulties: (1) a very fine spatial discretization is required to represent sharp local gradients correctly; (2) fine discretization results in high computational cost; (3) computation of higher-order derivatives for improved convergence rates and (4) curse of dimensionality in conventional numerical integration techniques. As a consequence, the practical applicability of phase field models is severely limited. The research presented in this thesis addresses the difficulties of the conventional numerical integration techniques for phase field modeling in quasi-static brittle fracture analysis. The first method relies on polynomial splines over hierarchical T-meshes (PHT-splines) in the framework of isogeometric analysis (IGA). An adaptive h-refinement scheme is developed based on the variational energy formulation of phase field modeling. The fourth-order phase field model provides increased regularity in the exact solution of the phase field equation and improved convergence rates for numerical solutions on a coarser discretization, compared to the second-order model. However, second-order derivatives of the phase field are required in the fourth-order model. Hence, at least a minimum of C1 continuous basis functions are essential, which is achieved using hierarchical cubic B-splines in IGA. PHT-splines enable the refinement to remain local at singularities and high gradients, consequently reducing the computational cost greatly. Unfortunately, when modeling complex geometries, multiple parameter spaces (patches) are joined together to describe the physical domain and there is typically a loss of continuity at the patch boundaries. This decrease of smoothness is dictated by the geometry description, where C0 parameterizations are normally used to deal with kinks and corners in the domain. Hence, the application of the fourth-order model is severely restricted. To overcome the high computational cost for the second-order model, we develop a dual-mesh adaptive h-refinement approach. This approach uses a coarser discretization for the elastic field and a finer discretization for the phase field. Independent refinement strategies have been used for each field. The next contribution is based on physics informed deep neural networks. The network is trained based on the minimization of the variational energy of the system described by general non-linear partial differential equations while respecting any given law of physics, hence the name physics informed neural network (PINN). The developed approach needs only a set of points to define the geometry, contrary to the conventional mesh-based discretization techniques. The concept of `transfer learning' is integrated with the developed PINN approach to improve the computational efficiency of the network at each displacement step. This approach allows a numerically stable crack growth even with larger displacement steps. An adaptive h-refinement scheme based on the generation of more quadrature points in the damage zone is developed in this framework. For all the developed methods, displacement-controlled loading is considered. The accuracy and the efficiency of both methods are studied numerically showing that the developed methods are powerful and computationally efficient tools for accurately predicting fractures. T3 - ISM-Bericht // Institut für Strukturmechanik, Bauhaus-Universität Weimar - 2021,1 KW - Phasenfeldmodell KW - Neuronales Netz KW - Sprödbruch KW - Isogeometric Analysis KW - Physics informed neural network KW - phase field KW - deep neural network KW - brittle fracture Y1 - 2021 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:gbv:wim2-20210304-43841 ER - TY - THES A1 - Foka, Zinovia T1 - The Space In-Between. Tracing Transformative Processes in Nicosia’s Buffer Zone. N2 - This thesis examines urban partition in Nicosia, the capital of Cyprus, and how its changing roles and shifting perceptions in a post-conflict setting reflect power relations, and their constant renegotiation. Nicosia, the capital of Cyprus, was officially divided in 1974 in the aftermath of an eighteen-year-long conflict between the island’s Turkish- and Greek-Cypriot communities. As a result, a heavily militarized Buffer Zone, established as an emergency measure against perpetuation of intercommunal violence, has been cutting through its historic centre ever since. This thesis departs from a genuine interest in the material and ideational dimensions of urban partition. How is it constructed, not merely in physical terms but in the minds of the societies affected by conflict? How is it established in official and everyday discourses? What kinds of mechanisms have been developed to maintain it, and make an inseparable part of the urban experience? Moreover, taking into account the consensus in relevant literature pertaining to the imperative for its removal, this thesis is inquiring into the relevance of peace agreements to overcoming urban partition. For this purpose, it also looks at narratives and practices that have attempted to contest it. The examples examined in this thesis offer pregnant analytical moments to understand Nicosia’s Buffer Zone as a dynamic social construct, accommodating multiple visions of and for the city. Its space ‘in-between’ facilitates encounters between various actors, accommodates new meanings, socio-spatial practices and diverse imaginaries. In this sense, urban partition is explored in this thesis as a phenomenon that transcends scales as well as temporalities, entwining past, present, and future. KW - Stadtforschung KW - Stadt KW - Zypern KW - urban partition KW - genealogy KW - space; power; knowledge KW - urban heritage KW - socio-spatial practices KW - Stadt / Teilung Y1 - 2021 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:gbv:wim2-20210531-44447 ER - TY - THES A1 - Fauth, Judith T1 - Ein handlungsorientiertes Entscheidungsmodell zur Feststellung der Genehmigungsfähigkeit von Bauvorhaben N2 - Die Auseinandersetzung mit der Digitalisierung ist in den letzten Jahren in den Medien, auf Konferenzen und in Ausschüssen der Bau- und Immobilienbranche angekommen. Während manche Bereiche Neuerungen hervorbringen und einige Akteure als Pioniere zu bezeichnen sind, weisen andere Themen noch Defizite hinsichtlich der digitalen Transformation auf. Zu dieser Kategorie kann auch das Baugenehmigungsverfahren gezählt werden. Unabhängig davon, wie Architekten und Ingenieure in den Planungsbüros auf innovative Methoden setzen, bleiben die Bauvorlagen bisher zuhauf in Papierform oder werden nach der elektronischen Einreichung in der Behörde ausgedruckt. Vorhandene Ressourcen, beispielsweise in Form eines Bauwerksinformationsmodells, die Unterstützung bei der Baugenehmigungsfeststellung bieten können, werden nicht ausgeschöpft. Um mit digitalen Werkzeugen eine Entscheidungshilfe für die Baugenehmigungsbehörden zu erarbeiten, ist es notwendig, den Ist-Zustand zu verstehen und Gegebenheiten zu hinterfragen, bevor eine Gesamtautomatisierung der innerbehördlichen Vorgänge als alleinige Lösung zu verfolgen ist. Mit einer inhaltlich-organisatorischen Betrachtung der relevanten Bereiche, die Einfluss auf die Baugenehmigungsfeststellung nehmen, wird eine Optimierung des Baugenehmigungsverfahrens in den Behörden angestrebt. Es werden die komplexen Bereiche, wie die Gesetzeslage, der Einsatz von Technologie aber auch die subjektiven Handlungsalternativen, ermittelt und strukturiert. Mit der Entwicklung eines Modells zur Feststellung der Baugenehmigungsfähigkeit wird sowohl ein Verständnis für Einflussfaktoren vermittelt als auch eine Transparenzsteigerung für alle Beteiligten geschaffen. Neben einer internationalen Literaturrecherche diente eine empirische Studie als Untersuchungsmethode. Die empirische Studie wurde in Form von qualitativen Experteninterviews durchgeführt, um den Ist-Zustand im Bereich der Baugenehmigungsverfahren festzustellen. Das erhobene Datenmaterial wurde aufbereitet und anschließend einer softwaregestützten Inhaltsanalyse unterzogen. Die Ergebnisse wurden in Kombination mit den Erkenntnissen der Literaturrecherche in verschiedenen Analysen als Modellgrundlage aufgearbeitet. Ergebnis der Untersuchung stellt ein Entscheidungsmodell dar, welches eine Lücke zwischen den gegenwärtigen Abläufen in den Baubehörden und einer Gesamtautomatisierung der Baugenehmigungsprüfung schließt. Die prozessorientierte Strukturierung entscheidungsrelevanter Sachverhalte im Modell ermöglicht eine Unterstützung bei der Baugenehmigungsfeststellung für Prüfer und Antragsteller. Das theoretische Modell konnte in Form einer Webanwendung in die Praxis übertragen werden. N2 - In recent years, the debate on digitization has been a topic of discussion in the media, at conferences and in committees of the construction and real estate industry. While some areas are producing innovations and some actors can be called pioneers, others still have deficits with regard to the digital transformation. The building permit process can also be considered among this category. Regardless of how architects and engineers use innovative methods in the planning offices, building applications are still often in paper form or are printed out after electronic submission to the authorities. Existing resources, for example in the form of a building information model, which can provide support in obtaining building permits, are not being utilized. In order to develop a decision support for the building authorities with digital tools, it is necessary to understand the actual conditions and to question the circumstances before an overall automation of the internal official processes can be pursued as the sole solution. With a content-based organizational view of the relevant components, which take influence on the building permit determination, an optimization of the building permit procedure in the authorities is aimed at. The complex components, such as the legal situation, the use of technology, but also the subjective alternatives for action, have to be determined and structured. The development of a model for determining building permit ability provides both an understanding of influencing factors and an increase in transparency for all parties involved. In addition to an international literature review, an empirical study served as a method of investigation. The empirical study was conducted in the form of qualitative expert interviews to determine the current state in the field of building permit procedures. The collected data material was prepared and subjected to a software-supported content analysis. In combination with the results of the literature review, the results were processed in various analyses as a model basis. The result of the investigation represents a decision model which closes a gap between the current processes at the building authorities and an overall automation of the building permit review. The process-oriented structuring of decision-relevant factors in the model enables support for the reviewers and the applicants during the building permit assessment. The theoretical model could be transferred into practice in the form of a web application. T3 - Schriften der Professur Baubetrieb und Bauverfahren - 39 KW - Baugenehmigung KW - Entscheidungsmodell KW - Bauantrag KW - Prozessmanagement KW - Projektmanagement KW - Building Permit KW - Decision-making KW - Building application KW - Process management KW - Project management Y1 - 2021 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:gbv:wim2-20210928-45093 UR - https://e-pub.uni-weimar.de/opus4/frontdoor/index/index/docId/4602 SN - 978-3-95773-299-6 N1 - Die englische Übersetzung der Dissertation ist unter https://doi.org/10.25643/bauhaus-universitaet.4602 erfasst und hier als URL Link hinterleg PB - Bauhaus-Universitätsverlag CY - Ilmtal-Weinstraße ER - TY - THES A1 - Fauth, Judith T1 - A process-oriented decision model for determining the permitability of construction projects N2 - In recent years, the discussion of digitalization has arrived in the media, at conferences, and in committees of the construction and real estate industry. While some areas are producing innovations and some contributors can be described as pioneers, other topics still show deficits with regard to digital transformation. The building permit process can also be counted in this category. Regardless of how architects and engineers in planning offices rely on innovative methods, building documents have so far remained in paper form in too many cases, or are printed out after electronic submission to the authority. Existing resources – for example in the form of a building information model, which could provide support in the building permit process – are not being taken advantage of. In order to use digital tools to support decision-making by the building permit authorities, it is necessary to understand the current situation and to question conditions before pursuing the overall automation of internal authority processes as the sole solution. With a substantive-organizational consideration of the relevant areas that influence building permit determination, an improvement of the building permit procedure within authorities is proposed. Complex areas – such as legal situations, the use of technology, as well as the subjective alternative action – are determined and structured. With the development of a model for the determination of building permitability, both an understanding of influencing factors is conveyed and an increase in transparency for all parties involved is created. In addition to an international literature review, an empirical study served as the research method. The empirical study was conducted in the form of qualitative expert interviews in order to determine the current state in the field of building permit procedures. The collected data material was processed and subsequently subjected to a software-supported content analysis. The results were processed, in combination with findings from the literature review, in various analyses to form the basis for a proposed model. The result of the study is a decision model that closes the gap between the current processes within the building authorities and an overall automation of the building permit review process. The model offers support to examiners and applicants in determining building permit eligibility, through its process-oriented structuring of decision-relevant facts. The theoretical model could be transferred into practice in the form of a web application. KW - Baugenehmigung KW - Entscheidungsmodell KW - Bauantrag KW - Prozessmanagement KW - Projektmanagement KW - Building permit KW - Building application KW - Decision-making KW - Process management KW - Project management Y1 - 2021 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:gbv:wim2-20220309-46020 UR - https://e-pub.uni-weimar.de/opus4/frontdoor/index/index/docId/4509 N1 - This work is a translation of the original dissertation (German language) which is accessible at: https://doi.org/10.25643/bauhaus-universitaet.4509 and deposited here as URL link. ER - TY - JOUR A1 - Ehlers, Jan A1 - Grimmer, Janine A1 - Strack, Veronika A1 - Huckauf, Anke T1 - The influence of sham feedback on physiological processing during fear-driven stimulation JF - PLOS ONE N2 - Biofeedback constitutes a well-established, non-invasive method to voluntary interfere in emotional processing by means of cognitive strategies. However, treatment durations exhibit strong inter-individual variations and first successes can often be achieved only after a large number of sessions. Sham feedback constitutes a rather untapped approach by providing feedback that does not correspond to the participant’s actual state. The current study aims to gain insights into mechanisms of sham feedback processing in order to support new techniques in biofeedback therapy. We carried out two experiments and applied different types of sham feedback on skin conductance responses and pupil size changes during affective processing. Results indicate that standardized but context-sensitive sham signals based on skin conductance responses exert a stronger influence on emotional regulation compared to individual sham feedback from ongoing pupil dynamics. Also, sham feedback should forego unnatural signal behavior to avoid irritation and skepticism among participants. Altogether, a reasonable combination of stimulus features and sham feedback characteristics enables to considerably reduce the actual bodily responsiveness already within a single session. KW - Biofeedback KW - Biofeedback KW - Sham Feedback KW - Affective Processing KW - OA-Publikationsfonds2021 Y1 - 2021 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:gbv:wim2-20210510-44249 UR - https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0251211 IS - Volume 16, issue 5, article e0251211 SP - 1 EP - 17 PB - PLOS CY - San Francisco, Calif. ER - TY - JFULL A1 - Dolff-Bonekämper, Gabi A1 - Paulus, Jörg A1 - Sellmann, Annika A1 - Vogel, Carolin A1 - Bargholz, Ortrun A1 - Herrmann, Moritz Peter A1 - Löffler, Beate A1 - Kretschmann, Schirin A1 - Lotter, Stefanie A1 - Ehrenpreis, David A1 - Bockelmann, Leo A1 - Langner, Sigrun A1 - Schönberger, Sonya A1 - Majdzadeh, Bahar ED - Bogner, Simone ED - Dolff-Bonekämper, Gabi ED - Meier, Hans-Rudolf T1 - Collecting Loss N2 - Wer sich mit "Identität" und "Erbe" befasst, also mit dem Zusammenhang zwischen der Konstituierung und Stabilität von Gemeinwesen und dem Bewahren von Gütern, Orten und Überlieferungen, kommt nicht umhin, sich auch mit Verlusten zu befassen. Verlust bezeichnet hier nicht die Abwesenheit eines Gutes, das Erbe war oder hätte werden können, sondern die soziale Beziehung zu dem verlorenen Gut und zu den Umständen seines Verlorengehens oder auch den Versuchen, es wiederzugewinnen. T3 - Schriftenreihe des DFG-Graduiertenkollegs 2227 "Identität und Erbe" - 1 KW - Verlust KW - Sammeln KW - Identität KW - Kulturerbe KW - Archiv Y1 - 2021 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:gbv:wim2-20201221-43217 PB - Bauhaus-Universitätsverlag CY - Ilmtal-Weinstraße ER - TY - CHAP A1 - Dokhanchi, Najmeh Sadat ED - Arnold, Jörg T1 - Reconstruction of the indoor air temperature distribution using acoustic travel-time tomography N2 - Acoustic travel-time tomography (ATOM) is being increasingly considered recently as a remote sensing methodology to determine the indoor air temperatures distribution. It employs the relationship between the sound velocities along sound-paths and their related travel-times through measured room-impulse-response (RIR). Thus, the precise travel-time estimation is of critical importance which can be performed by applying an analysis time-window method. In this study, multiple analysis time-windows with different lengths are proposed to overcome the challenge of accurate detection of the travel-times at RIR. Hence, the ATOM-temperatures distribution has been measured at the climate chamber lab of the Bauhaus-University Weimar. As a benchmark, the temperatures of NTC thermistors are compared to the reconstructed temperatures derived from the ATOM technique illustrating this technique can be a reliable substitute for traditional thermal sensors. The numerical results indicate that the selection of an appropriate analysis time-window significantly enhances the accuracy of the reconstructed temperatures distribution. KW - Bauphysik KW - Akustische Laufzeit-Tomographie KW - Acoustic Travel-Time Tomography KW - Bauklimatik Y1 - 2021 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:gbv:wim2-20220622-46593 ER - TY - THES A1 - Chawdhury, Samir T1 - Partitioned Algorithms using Vortex Particle Methods for Fluid−Structure Interaction of Thin-walled Flexible Structures N2 - Structures under wind action can exhibit various aeroelastic interaction phenomena, which can lead to destructive and catastrophic events. Such unstable interaction can be beneficially used for small-scale aeroelastic energy harvesting. Proper understanding and prediction of fluid−structure interactions (FSI) phenomena are therefore crucial in many engineering fields. This research intends to develop coupled FSI models to extend the applicability of Vortex Particle Methods (VPM) for numerically analysing the complex FSI of thin-walled flexible structures under steady and fluctuating incoming flows. In this context, the flow around deforming thin bodies is analysed using the two-dimensional and pseudo-three-dimensional implementations of VPM. The structural behaviour is modelled and analysed using the Finite Element Method. The partitioned coupling approach is considered because of the flexibility of using different mathematical procedures for solving fluid and solid mechanics. The developed coupled models are validated with several benchmark FSI problems in the literature. Finally, the models are applied to several fundamental and application field of FSI problems of different thin-walled flexible structures irrespective of their size. T3 - Schriftenreihe des Instituts für Konstruktiven Ingenieurbau - 37 KW - Windenergie KW - Numerisches Verfahren KW - Energieerzeugung KW - Computational wind engineering KW - Aeroelastic instabilities KW - Coupled numerical methods KW - Thin-walled structures KW - Aeroelastic energy harvesting Y1 - 2021 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:gbv:wim2-20230703-64042 UR - https://asw-verlage.de/katalog/partitioned_algorithms_using_vor-2372.html SN - 978-3-95773-297-2 PB - arts + science weimar GmbH CY - Weimar ER - TY - JOUR A1 - Cappachione, Clotilde A1 - Partschefeld, Stephan A1 - Osburg, Andrea A1 - Gliubizzi, Rocco A1 - Gaeta, Carmine T1 - Modified Carboxymethylcellulose-Based Scaffolds as New Potential Ecofriendly Superplasticizers with a Retardant Effect for Mortar: From the Synthesis to the Application JF - Materials N2 - This article is focused on the research and development of new cellulose ether derivatives as innovative superplasticizers for mortar systems. Several synthetic strategies have been pursued to obtain new compounds to study their properties on cementitious systems as new bio-based additives. The new water-soluble admixtures were synthesized using a complex carboxymethylcellulose-based backbone that was first hydrolyzed and then sulfo-ethylated in the presence of sodium vinyl sulphonate. Starting with a complex biopolymer that is widely known as a thickening agent was very challenging. Only by varying the hydrolysis times and temperatures of the reactions was achieved the aimed goal. The obtained derivatives showed different molecular weight (Mw) and anionic charges on their backbones. An improvement in shear stress and dynamic viscosity values of CEM II 42.5R cement was observed with the samples obtained with a longer time of higher temperature hydrolysis and sulfo-ethylation. Investigations into the chemical nature of the pore solution, calorimetric studies and adsorption experiments clearly showed the ability of carboxymethyl cellulose superplasticizer (CMC SP) to interact with cement grains and influence hydration processes within a 48-h time window, causing a delay in hydration reactions in the samples. The fluidity of the cementitious matrices was ascertained through slump test and preliminary studies of mechanical and flexural strength of the hardened mortar formulated with the new ecological additives yielded values in terms of mechanical properties. Finally, the computed tomography (CT) images completed the investigation of the pore network structure of hardened specimens, highlighting their promising structure porosity. KW - Mörtel KW - Verflüssigung KW - superplasticizers KW - carboxymethylcellulose KW - mortar KW - OA-Publikationsfonds2021 Y1 - 2021 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:gbv:wim2-20210804-44689 UR - https://www.mdpi.com/1996-1944/14/13/3569 VL - 2021 IS - volume 14, issue 13, article 3569 SP - 1 EP - 17 PB - MDPI CY - Basel ER - TY - JOUR A1 - Buschow, Christopher A1 - Possler, Daniel A1 - Scheper, Jule T1 - Teaching Media Entrepreneurship: How A Start-up Simulation Can Increase Students’ Knowledge and Encourage Them to Work in Entrepreneurial Contexts JF - Teaching Journalism and Mass Communication N2 - Entrepreneurship and start-up activities are seen as a key response to recent upheavals in the media industry: Newly founded ventures can act as important drivers for industry transformation and renewal, pioneering new products, business models, and organizational designs (e.g. Achtenhagen, 2017; Buschow & Laugemann, 2020). In principle, media students represent a crucial population of nascent entrepreneurs: individuals who will likely become founders of start-ups (Casero-Ripollés et al., 2016). However, their willingness to start a new business is generally considered to be rather low (Goyanes, 2015), and for journalism students, the idea of innovation tends to be conservative, following traditional norms and professional standards (Singer & Broersma, 2020). In a sample of Spanish journalism students, López-Meri et al. (2020) found that one of the main barriers to entrepreneurial intentions is that students feel they lack knowledge and training in entrepreneurship. In the last 10 years, a wide variety of entrepreneurship education courses have been set up in media departments of colleges and universities worldwide. These programs have been designed to sensitize and prepare communications, media and journalism students to think and act entrepreneurially (e.g. Caplan et al., 2020; Ferrier, 2013; Ferrier & Mays, 2017; Hunter & Nel, 2011). Entrepreneurial competencies and practices not only play a crucial role for start-ups, but, in imes of digital transformation, are increasingly sought after by legacy media companies as well (Küng, 2015). At the Department of Journalism and Communication Research, Hanover University of Music, Drama and Media, Germany, we have been addressing these developments with the “Media Entrepreneurship” program. The course, established in 2013, aims to provide fundamental knowledge of entrepreneurship, as well as promoting students‘ entrepreneurial thinking and behavior. This article presents the pedagogical approach of the program and investigates learning outcomes. By outlining and evaluating the Media Entrepreneurship program, this article aims to promote good practices of entrepreneurship education in communications, media and journalism, and to reflect on the limitations of such programs. KW - Medienwirtschaft KW - Entrepreneurship KW - Journalismus KW - Studium KW - Medienwissenschaft KW - Start-up-Simulation Y1 - 2021 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:gbv:wim2-20210729-44628 UR - https://aejmc.us/wp-content/uploads/sites/9/2021/07/TJMC-11.1-Buschow-et-al.pdf VL - 2021 IS - Volume 11, Nr. 1 SP - 65 EP - 69 PB - Small Programs Interest Group ER - TY - BOOK A1 - Brokow-Loga, Anton A1 - Eckardt, Frank T1 - Stadtpolitik für alle N2 - Die Corona-Krise hat die Erosion städtischer Solidarität offen zu Tage treten lassen. Dagegen bringen Anton Brokow-Loga und Frank Eckardt in dieser Schrift die praktische Utopie einer solidarischen Postwachstumsstadt „auf den Punkt“. Vom Commoning über die Umverteilung der städtischen Flächen bis zu einer sozial-ökologischen Verkehrswende: Eine progressive Stadtpolitik für alle überwindet bisheriges Schubladendenken. Sie setzt stattdessen auf heterogene Zusammenhänge und ungewöhnliche Bündnisse. Zu dem hier umrissenen Vorhaben gehört auch, eine basisdemokratisch orientierte Stadtpolitik mit dem Ziel einer umfassenden Transformation von Stadt und Gesellschaft zu verknüpfen. Wie kann ein Blick auf die kommunale Ebene helfen, globalen Ungerechtigkeiten zu begegnen? Welchen Weg weisen munizipalistische Plattformen und Vergemeinschaftungen jenseits von Privat- oder Staatseigentum? KW - Transformation KW - Stadtplanung KW - Kommunalpolitik KW - Postwachstumsökonomie KW - Pandemie KW - Stadtpolitik KW - Postwachstumsstadt KW - Pandemie KW - Corona KW - Transformationsstrategien KW - OA-Publikationsfonds2021 Y1 - 2021 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:gbv:wim2-20210315-43904 PB - Graswurzelrevolution CY - Heidelberg ER - TY - THES A1 - Bockelmann, Leo T1 - Zeit, dass sich was dreht. Windenergieanlagen aus denkmalkundlicher Perspektive N2 - Knapp 30.000 Windenergieanlagen zwischen Nordsee und Alpen lassen unübersehbar erkennen, dass sich unser Energiesystem in einer umfassenden Transformation befindet. Allenthalben erfährt diese Entwicklung eine breite und kontroverse Rezeption und auch in der Denkmalpflege werden Windenergieanlagen aufgrund ihrer mitunter erheblichen Auswirkungen auf die Landschaft noch überwiegend als Störung wahrgenommen. Diese Arbeit nimmt dagegen die historische Entwicklung in den Blick und plädiert dafür, Windenergieanlagen als bedeutendes Kulturerbe zu verstehen. Angesichts des Voranschreitens der Energiewende wird angenommen, dass gerade älteren Modellen als baulichen Zeugnissen umfangreicher energiepolitischer Veränderungen seit den 1970er Jahren eine hohe Bedeutung zugeschrieben werden kann. Daher besteht das Ziel darin, Windenergieanlagen herauszuarbeiten, welche als hervorragende Zeugnisse der Entwicklung der Windenergienutzung in Deutschland zu bewerten sind. Zur Annäherung werden diese zunächst als Untersuchungsgegenstand typologisch abgegrenzt. Eine wesentliche Besonderheit von Windenergieanlagen besteht darin, dass sie im Verhältnis zur eigentlichen Flächenversiegelung durch ihre vertikale Struktur erhebliche visuelle Auswirkungen auf die Landschaft haben. Anschließend wird die Entwicklung der Windenergienutzung seit den 1970er Jahren genauer betrachtet, welche insgesamt nicht linear verlief und von vielen Konflikten gekennzeichnet ist. Diese muss im Kontext eines wachsenden Umweltbewusstseins verstanden werden, das umfangreiche energiepolitische Veränderungen zur Folge hatte. Auf dieser Grundlage werden schließlich in einer denkmalkundlichen Reihenuntersuchung Windenergieanlagen herausgearbeitet, welche in hervorragender Weise von der Entwicklung zeugen. Die Auswahl bleibt allerdings mit sechs Objekten im Verhältnis zum Gesamtbestand von knapp 30.000 Anlagen relativ beschränkt, weil das auf die Abgrenzung von Besonderheiten ausgelegte etablierte Denkmalverständnis bei einem zeitlich so dichten Bestand gleichartiger Bauwerke an eine Grenze kommt. Abschließend werden mögliche Erhaltungsperspektiven sowie denkmaltheoretische und -praktische Schlussfolgerungen diskutiert. Dabei ist unbedingt ein Erhalt am Ursprungsstandort anzustreben, wobei im Einzelfall entschieden werden muss, ob Belange des Funktions- oder Substanzerhaltes höher zu gewichten sind. Die skizzierten Auswahlprobleme regen darüber hinaus zur Diskussion zusätzlicher denkbarer Bewertungskategorien an, wobei sich insbesondere die gesellschaftliche Wahrnehmung und ökologische Werte aufdrängen. Zudem kann für die stärkere Berücksichtigung von Funktionszusammenhängen bei der Betrachtung technischer Infrastruktur in der Denkmalpflege plädiert werden. Insgesamt führt die denkmalkundliche Auseinandersetzung mit Windenergieanlagen damit weit über die Herausarbeitung einzelner Objekte hinaus und macht eindrücklich auf aktuelle Herausforderungen der Denkmalpflege und darüber hinaus aufmerksam. KW - Industriekultur KW - Denkmalpflege KW - Windenergie KW - Landschaft KW - Kulturerbe KW - Heritage KW - Infrastrukturgeschichte KW - Technikgeschichte KW - Klimaschutz KW - Energiewende Y1 - 2021 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:gbv:wim2-20211210-45439 ER - TY - THES A1 - Bielik, Martin T1 - FORM-ACTIVITY-MOVEMENT INTERACTION MODEL N2 - This dissertation investigates the interactions between urban form, allocation of activities, and pedestrian movement in the context of urban planning. The ability to assess the long-term impact of urban planning decisions on what people do and how they get there is of central importance, with various disciplines addressing this topic. This study focuses on approaches proposed by urban morphologists, urban economists, and transportation planners, each aiming the attention at a different part of the form-activity-movement interaction. Even though there is no doubt about the advantages of these highly focused approaches, it remains unclear what is the cost of ignoring the effect of some interactions while considering others. The general aim of this dissertation is to empirically test the validity of the individual models and quantify the impact of this isolationist approach on their precision and bias. For this purpose, we propose a joined form-activity-movement interaction model and conduct an empirical study in Weimar, Germany. We estimate how the urban form and activities affect movement as well as how movement and urban form affect activities. By estimating these effects in isolation and simultaneously, we assess the bias of the individual models. On the one hand, the empirical study results confirm the significance of all interactions suggested by the individual models. On the other hand, we were able to show that when these interactions are estimated in isolation, the resulting predictions are biased. To conclude, we do not question the knowledge brought by transportation planners, urban morphologists, and urban economists. However, we argue that it might be of little use on its own. We see the relevance of this study as being twofold. On the one hand, we proposed a novel methodological framework for the simultaneous estimation of the form-activity-movement interactions. On the other hand, we provide empirical evidence about the strengths and limitations of current approaches. KW - Stadtplanung Y1 - 2021 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:gbv:wim2-20210407-43970 ER - TY - THES A1 - Bianco, Marcelo José T1 - Coupling between Shell and Generalized Beam Theory (GBT) elements N2 - In the last decades, Finite Element Method has become the main method in statics and dynamics analysis in engineering practice. For current problems, this method provides a faster, more flexible solution than the analytic approach. Prognoses of complex engineer problems that used to be almost impossible to solve are now feasible. Although the finite element method is a robust tool, it leads to new questions about engineering solutions. Among these new problems, it is possible to divide into two major groups: the first group is regarding computer performance; the second one is related to understanding the digital solution. Simultaneously with the development of the finite element method for numerical solutions, a theory between beam theory and shell theory was developed: Generalized Beam Theory, GBT. This theory has not only a systematic and analytical clear presentation of complicated structural problems, but also a compact and elegant calculation approach that can improve computer performance. Regrettably, GBT was not internationally known since the most publications of this theory were written in German, especially in the first years. Only in recent years, GBT has gradually become a fertile research topic, with developments from linear to non-linear analysis. Another reason for the misuse of GBT is the isolated application of the theory. Although recently researches apply finite element method to solve the GBT's problems numerically, the coupling between finite elements of GBT and other theories (shell, solid, etc) is not the subject of previous research. Thus, the main goal of this dissertation is the coupling between GBT and shell/membrane elements. Consequently, one achieves the benefits of both sides: the versatility of shell elements with the high performance of GBT elements. Based on the assumptions of GBT, this dissertation presents how the separation of variables leads to two calculation's domains of a beam structure: a cross-section modal analysis and the longitudinal amplification axis. Therefore, there is the possibility of applying the finite element method not only in the cross-section analysis, but also the development for an exact GBT's finite element in the longitudinal direction. For the cross-section analysis, this dissertation presents the solution of the quadratic eigenvalue problem with an original separation between plate and membrane mechanism. Subsequently, one obtains a clearer representation of the deformation mode, as well as a reduced quadratic eigenvalue problem. Concerning the longitudinal direction, this dissertation develops the novel exact elements, based on hyperbolic and trigonometric shape functions. Although these functions do not have trivial expressions, they provide a recursive procedure that allows periodic derivatives to systematise the development of stiffness matrices. Also, these shape functions enable a single-element discretisation of the beam structure and ensure a smooth stress field. From these developments, this dissertation achieves the formulation of its primary objective: the connection of GBT and shell elements in a mixed model. Based on the displacement field, it is possible to define the coupling equations applied in the master-slave method. Therefore, one can model the structural connections and joints with finite shell elements and the structural beams and columns with GBT finite element. As a side effect, the coupling equations limit the displacement field of the shell elements under the assumptions of GBT, in particular in the neighbourhood of the coupling cross-section. Although these side effects are almost unnoticeable in linear analysis, they lead to cumulative errors in non-linear analysis. Therefore, this thesis finishes with the evaluation of the mixed GBT-shell models in non-linear analysis. T3 - ISM-Bericht // Institut für Strukturmechanik, Bauhaus-Universität Weimar - 2021,2 KW - Biegetheorie KW - Finite Elemente Methode KW - Generalized Bean Theory KW - Finite Element KW - Thin-walled Structures KW - Cross-Section Warping KW - Cross-Section Distortion KW - Verallgemeinerte Technische Biegetheorie Y1 - 2021 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:gbv:wim2-20210315-43914 ER - TY - THES A1 - Berhe, Asgedom Haile T1 - Mitigating Risks of Corruption in Construction: A theoretical rationale for BIM adoption in Ethiopia N2 - This PhD thesis sets out to investigate the potentials of Building Information Modeling (BIM) to mitigate risks of corruption in the Ethiopian public construction sector. The wide-ranging capabilities and promises of BIM have led to the strong perception among researchers and practitioners that it is an indispensable technology. Consequently, it has become the frequent subject of science and research. Meanwhile, many countries, especially the developed ones, have committed themselves to applying the technology extensively. Increasing productivity is the most common and frequently cited reason for that. However, both technology developers and adopters are oblivious to the potentials of BIM in addressing critical challenges in the construction sector, such as corruption. This particularly would be significant in developing countries like Ethiopia, where its problems and effects are acute. Studies reveal that bribery and corruption have long pervaded the construction industry worldwide. The complex and fragmented nature of the sector provides an environment for corruption. The Ethiopian construction sector is not immune from this epidemic reality. In fact, it is regarded as one of the most vulnerable sectors owing to varying socio-economic and political factors. Since 2015, Ethiopia has started adopting BIM, yet without clear goals and strategies. As a result, the potential of BIM for combating concrete problems of the sector remains untapped. To this end, this dissertation does pioneering work by showing how collaboration and coordination features of the technology contribute to minimizing the opportunities for corruption. Tracing loopholes, otherwise, would remain complex and ineffective in the traditional documentation processes. Proceeding from this anticipation, this thesis brings up two primary questions: what are areas and risks of corruption in case of the Ethiopian public construction projects; and how could BIM be leveraged to mitigate these risks? To tackle these and other secondary questions, the research employs a mixed-method approach. The selected main research strategies are Survey, Grounded Theory (GT) and Archival Study. First, the author disseminates an online questionnaire among Ethiopian construction engineering professionals to pinpoint areas of vulnerability to corruption. 155 responses are compiled and scrutinized quantitatively. Then, a semi-structured in-depth interview is conducted with 20 senior professionals, primarily to comprehend opportunities for and risks of corruption in those identified highly vulnerable project stages and decision points. At the same time, open interviews (consultations) are held with 14 informants to be aware of state of the construction documentation, BIM and loopholes for corruption in the country. Consequently, these qualitative data are analyzed utilizing the principles of GT, heat/risk mapping and Social Network Analysis (SNA). The risk mapping assists the researcher in the course of prioritizing corruption risks; whilst through SNA, methodically, it is feasible to identify key actors/stakeholders in the corruption venture. Based on the generated research data, the author constructs a [substantive] grounded theory around the elements of corruption in the Ethiopian public construction sector. This theory, later, guides the subsequent strategic proposition of BIM. Finally, 85 public construction related cases are also analyzed systematically to substantiate and confirm previous findings. By ways of these multiple research endeavors that is based, first and foremost, on the triangulation of qualitative and quantitative data analysis, the author conveys a number of key findings. First, estimations, tender document preparation and evaluation, construction material as well as quality control and additional work orders are found to be the most vulnerable stages in the design, tendering and construction phases respectively. Second, middle management personnel of contractors and clients, aided by brokers, play most critical roles in corrupt transactions within the prevalent corruption network. Third, grand corruption persists in the sector, attributed to the fact that top management and higher officials entertain their overriding power, supported by the lack of project audits and accountability. Contrarily, individuals at operation level utilize intentional and unintentional 'errors’ as an opportunity for corruption. In light of these findings, two conceptual BIM-based risk mitigation strategies are prescribed: active and passive automation of project audits; and the monitoring of project information throughout projects’ value chain. These propositions are made in reliance on BIM’s present dimensional capabilities and the promises of Integrated Project Delivery (IPD). Moreover, BIM’s synchronous potentials with other technologies such as Information and Communication Technology (ICT), and Radio Frequency technologies are topics which received a treatment. All these arguments form the basis for the main thesis of this dissertation, that BIM is able to mitigate corruption risks in the Ethiopian public construction sector. The discourse on the skepticisms about BIM that would stem from the complex nature of corruption and strategic as well as technological limitations of BIM is also illuminated and complemented by this work. Thus, the thesis uncovers possible research gaps and lays the foundation for further studies. KW - Building Information Modeling KW - Korruption KW - Risikomanagement KW - Äthiopien KW - Corruption KW - BIM KW - Risk management KW - Construction KW - Ethiopia Y1 - 2021 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:gbv:wim2-20211007-45175 ER - TY - JOUR A1 - Becher, Lia A1 - Gena, Amayu Wakoya A1 - Alsaad, Hayder A1 - Richter, Bernhard A1 - Spahn, Claudia A1 - Völker, Conrad T1 - The spread of breathing air from wind instruments and singers using schlieren techniques JF - Indoor Air N2 - The spread of breathing air when playing wind instruments and singing was investigated and visualized using two methods: (1) schlieren imaging with a schlieren mirror and (2) background-oriented schlieren (BOS). These methods visualize airflow by visualizing density gradients in transparent media. The playing of professional woodwind and brass instrument players, as well as professional classical trained singers were investigated to estimate the spread distances of the breathing air. For a better comparison and consistent measurement series, a single high note, a single low note, and an extract of a musical piece were investigated. Additionally, anemometry was used to determine the velocity of the spreading breathing air and the extent to which it was quantifiable. The results showed that the ejected airflow from the examined instruments and singers did not exceed a spreading range of 1.2 m into the room. However, differences in the various instruments have to be considered to assess properly the spread of the breathing air. The findings discussed below help to estimate the risk of cross-infection for wind instrument players and singers and to develop efficacious safety precautions, which is essential during critical health periods such as the current COVID-19 pandemic. KW - Covid-19 KW - Pandemie KW - Blasinstrument KW - Gesang KW - Schlierenmethode KW - airborne infection KW - background-oriented schlieren KW - schlieren imaging Y1 - 2021 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:gbv:wim2-20220209-45817 UR - https://onlinelibrary.wiley.com/doi/full/10.1111/ina.12869 VL - 2021 IS - volume 31, issue 6 SP - 1798 EP - 1814 PB - Wiley Blackwell CY - Oxford ER - TY - JOUR A1 - Baron, Nicole T1 - Verflechtungen im städtischen Gefüge. Rezension zu Barbara Heer (2019): Cities of entanglements. Social life in Johannesburg and Maputo through ethnographic comparison JF - sub\urban. Zeitschrift für Kritische Stadtforschung N2 - Dieser Artikel rezensiert die überarbeitete Version von Barbara Heers Dissertation zu städtischen Verflechtungen in Johannesburg und Maputo. Das Buch ist 2019 im Transcript Verlag erschienen und umfasst 337 Seiten. KW - Südafrika KW - Segregation KW - Diversität KW - Johannesburg KW - Segregation KW - Nachbarschaft KW - Religion KW - OA-Publikationsfonds2021 Y1 - 2021 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:gbv:wim2-20210806-44785 UR - https://zeitschrift-suburban.de/sys/index.php/suburban/article/view/664 VL - 2021 IS - Band 9, Heft 1/2 SP - 235 EP - 240 PB - sub\urban e. V. CY - Berlin ER - TY - THES A1 - Baron, Nicole T1 - Natural Urban Resilience: Understanding general urban resilience through Addis Ababa’s inner city N2 - This dissertation describes the urban actors and spatial practices that contribute to natural urban resilience in Addis Ababa’s inner city. Natural urban resilience is a non-strategical and bottom-up, everyday form of general urban resilience – an urban system’s ability to maintain its essential characteristics under any change. This study gains significance by exposing conceptual gaps in the current un-derstanding of general urban resilience and highlighting its unconvincing applicability to African cities. This study attains further relevance by highlighting the danger of the ongoing large-scale redevelopment of the inner city. The inner city has naturally formed, and its urban memory, spaces, and social cohesion contribute to its primarily low-income population’s resilience. This thesis argues that the inner city’s demolition poses an incalculable risk of maladaptation to future stresses and shocks for Addis Ababa. The city needs a balanced urban discourse that highlights the inner city’s qualities and suggests feasible urban transformation measures. “Natural Urban Resilience” contributes an empirical study to the debate by identifying those aspects of the inner city that contribute to general resilience and identifies feasible action areas. This study develops a qualitative research design for a single case study in Addis Ababa. The data is obtained through expert interviews, interviews with resi-dents, and the analysis of street scene photos, which are abstracted using Grounded Theory. That way, this thesis provides first-time knowledge about who and what generates urban resilience in the inner city of Addis Ababa and how. Furthermore, the study complements existing theories on general urban resilience. It provides a detailed understanding of the change mechanisms in resilience, of which it identifies four: adaptation, upgrading, mitigation, and resistance. It also adapts the adaptive cycle, a widely used concept in resilience thinking, conceptually for urban environments. The study concludes that the inner city’s continued redevelopment poses an incalculable threat to the entire city. Therefore, “Natural urban resilience” recommends carefully weighing any intervention in the inner city to promote Addis Ababa’s overall resilience. This dissertation proposes a pattern language for natural urban resilience to support these efforts and to translate the model of natural urban resilience into practice. KW - Stadtforschung KW - Urbanistik KW - Stadtsoziologie KW - Urban studies KW - Urban resilience KW - Built environment KW - Co-production KW - Grounded theory Y1 - 2021 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:gbv:wim2-20210428-44166 ER - TY - THES A1 - Arzmi, Azmah T1 - Reinterpreting Marzahn, Berlin & Petržalka, Bratislava: From Process of State Socialist Utopia to Utopia of State Capitalist Process N2 - Housing estates were fundamentally conceived upon state socialist utopia ideas to provide standard housing for citizens. While former state socialist housing estates have been extensively researched in the field of architecture, urban and sociology studies, there is still a gap in identifying how production processes affect morphological changes during the post-socialist era. This thesis compares the processes in the production of the largest housing estates of Marzahn in GDR and Petržalka in Czechoslovakia from 1970 to 1989 through contextual analysis of primary and secondary sources, which include visual maps, diagrams from professional architecture and planning journals, government documents and textbooks, as well as academic journals, books and newspaper articles. Then it discusses how these processes inadvertently created conducive conditions affecting their development in the market economy after 1989. It then interprets the results through application of Actor-Network Theory and Historical Institutionalism, while conceptualising them through David Harvey’s dialectical utopianism theory. Harvey (2000) delineates two types of utopia, one of spatial form and one of process. The former refers to materialised ideals in physical forms whereas the latter refers to the ongoing process of spatializing. The thesis aims to show how the production of Marzahn in GDR was more path dependent on policies established in 1950s and 1960s whereas Petržalka was a product of new Czechoslovakian policies in 1970s, changing aspects of the urban planning process, a manifestation of a more emphatic technocratic thinking on a wider scale. This ultimately influences the trajectories of development after 1989, showing more effects in Petržalka. KW - Kulturerbe KW - state socialist utopia KW - centralized planning KW - GDR KW - Czechoslovakia KW - mass housing estates Y1 - 2021 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:gbv:wim2-20210315-43927 ER - TY - JOUR A1 - Anic, Filip A1 - Penava, Davorin A1 - Sarhosis, Vasilis A1 - Abrahamczyk, Lars T1 - Development and Calibration of a 3D Micromodel for Evaluation of Masonry Infilled RC Frame Structural Vulnerability to Earthquakes JF - Geosciences N2 - Within the scope of literature, the influence of openings within the infill walls that are bounded by a reinforced concrete frame and excited by seismic drift forces in both in- and out-of-plane direction is still uncharted. Therefore, a 3D micromodel was developed and calibrated thereafter, to gain more insight in the topic. The micromodels were calibrated against their equivalent physical test specimens of in-plane, out-of-plane drift driven tests on frames with and without infill walls and openings, as well as out-of-plane bend test of masonry walls. Micromodels were rectified based on their behavior and damage states. As a result of the calibration process, it was found that micromodels were sensitive and insensitive to various parameters, regarding the model’s behavior and computational stability. It was found that, even within the same material model, some parameters had more effects when attributed to concrete rather than on masonry. Generally, the in-plane behavior of infilled frames was found to be largely governed by the interface material model. The out-of-plane masonry wall simulations were governed by the tensile strength of both the interface and masonry material model. Yet, the out-of-plane drift driven test was governed by the concrete material properties. KW - Verwundbarkeit KW - Ausfachung KW - Stahlbeton KW - RC frames KW - unreinforced masonry infill walls KW - openings KW - structural vulnerability KW - out-of-plane seismic load KW - OA-Publikationsfonds2021 Y1 - 2021 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:gbv:wim2-20211202-45370 UR - https://www.mdpi.com/2076-3263/11/11/468 VL - 2021 IS - Voume 11, issue 11, article 468 PB - MDPI CY - Basel ER - TY - JOUR A1 - Alsaad, Hayder A1 - Völker, Conrad T1 - Qualitative evaluation of the flow supplied by personalized ventilation using schlieren imaging and thermography JF - Building and Environment N2 - Personalized ventilation (PV) is a mean of delivering conditioned outdoor air into the breathing zone of the occupants. This study aims to qualitatively investigate the personalized flows using two methods of visualization: (1) schlieren imaging using a large schlieren mirror and (2) thermography using an infrared camera. While the schlieren imaging was used to render the velocity and mass transport of the supplied flow, thermography was implemented to visualize the air temperature distribution induced by the PV. Both studies were conducted using a thermal manikin to simulate an occupant facing a PV outlet. As a reference, the flow supplied by an axial fan and a cased axial fan was visualized with the schlieren system as well and compared to the flow supplied by PV. Schlieren visualization results indicate that the steady, low-turbulence flow supplied by PV was able to penetrate the thermal convective boundary layer encasing the manikin's body, providing clean air for inhalation. Contrarily, the axial fan diffused the supplied air over a large target area with high turbulence intensity; it only disturbed the convective boundary layer rather than destroying it. The cased fan supplied a flow with a reduced target area which allowed supplying more air into the breathing zone compared to the fan. The results of thermography visualization showed that the supplied cool air from PV penetrated the corona-shaped thermal boundary layer. Furthermore, the supplied air cooled the surface temperature of the face, which indicates the large impact of PV on local thermal sensation and comfort. KW - Bildverarbeitung KW - Photothermische Methode KW - Visualisierung KW - Belüftung KW - Lüftungsanlage KW - Schlieren imaging KW - Thermography KW - Visualization KW - Personalized ventilation KW - Axial fan Y1 - 2021 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:gbv:wim2-20211008-45117 UR - https://www.sciencedirect.com/science/article/abs/pii/S0360132319306602?via%3Dihub N1 - This is the accepted manuscript of the article published by Elsevier in Building and Environment 167 (2020) 106450, which can be found at https://doi.org/10.1016/j.buildenv.2019.106450. VL - 2020 IS - Volume 167, article 106450 PB - Elsevier CY - New York ER - TY - CHAP A1 - Alsaad, Hayder A1 - Völker, Conrad T1 - Measuring and visualizing the flow supplied by personalized ventilation T2 - Proceedings Book Roomvent 2020 N2 - This study investigates the flow supplied by personalized ventilation (PV) by means of anemometer measurements and schlieren visualization. The study was conducted using a thermal manikin to simulate a seated occupant facing a PV outlet. Air velocity was measured at multiple points in the flow field; the collected velocity values were used to calculate the turbulence intensity. Results indicated that PV was supplying air with low turbulence intensity that was able to penetrate the convective boundary layer of the manikin to supply clean air for inhalation. The convective boundary layer, however, obstructed the supplied flow and reduced its velocity by a total of 0.26 m/s. The PV flow preserved its value until about 10 cm from the face where velocity started to drop. Further investigations were conducted to test a PV diffuser with a relatively large outlet diameter (18 cm). This diffuser was developed using 3d-modelling and 3d-printing. The diffuser successfully distributed the flow over the larger outlet area. However, the supplied velocity and turbulence fields were not uniform across the section. KW - Belüftung KW - Luftqualität KW - Personalized ventilation KW - Schlieren imaging KW - Air quality KW - Thermal manikin Y1 - 2021 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:gbv:wim2-20220622-46573 CY - Turin, Italy ER - TY - JOUR A1 - Alsaad, Hayder A1 - Hartmann, Maria A1 - Voelker, Conrad T1 - The effect of a living wall system designated for greywater treatment on the hygrothermal performance of the facade JF - Energy and Buildings N2 - Besides their multiple known benefits regarding urban microclimate, living walls can be used as decentralized stand-alone systems to treat greywater locally at the buildings. While this offers numerous environmental advantages, it can have a considerable impact on the hygrothermal performance of the facade as such systems involve bringing large quantities of water onto the facade. As it is difficult to represent complex entities such as plants in the typical simulation tools used for heat and moisture transport, this study suggests a new approach to tackle this challenge by coupling two tools: ENVI-Met and Delphin. ENVI-Met was used to simulate the impact of the plants to determine the local environmental parameters at the living wall. Delphin, on the other hand, was used to conduct the hygrothermal simulations using the local parameters calculated by ENVI-Met. Four wall constructions were investigated in this study: an uninsulated brick wall, a precast concrete plate, a sandy limestone wall, and a double-shell wall. The results showed that the living wall improved the U-value, the exterior surface temperature, and the heat flux through the wall. Moreover, the living wall did not increase the risk of moisture in the wall during winter and eliminated the risk of condensation. KW - Feuchteleitung KW - Diffusionswärme KW - Heat transport KW - Moisture transport KW - Living wall KW - Delphin KW - ENVI-Met Y1 - 2021 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:gbv:wim2-20240116-65299 UR - https://www.sciencedirect.com/science/article/pii/S0378778821009956 VL - 2022 IS - volume 255, article 111711 ER - TY - JOUR A1 - Alkam, Feras A1 - Lahmer, Tom T1 - A robust method of the status monitoring of catenary poles installed along high-speed electrified train tracks JF - Results in Engineering N2 - Electric trains are considered one of the most eco-friendly and safest means of transportation. Catenary poles are used worldwide to support overhead power lines for electric trains. The performance of the catenary poles has an extensive influence on the integrity of the train systems and, consequently, the connected human services. It became a must nowadays to develop SHM systems that provide the instantaneous status of catenary poles in- service, making the decision-making processes to keep or repair the damaged poles more feasible. This study develops a data-driven, model-free approach for status monitoring of cantilever structures, focusing on pre-stressed, spun-cast ultrahigh-strength concrete catenary poles installed along high-speed train tracks. The pro-posed approach evaluates multiple damage features in an unfied damage index, which leads to straightforward interpretation and comparison of the output. Besides, it distinguishes between multiple damage scenarios of the poles, either the ones caused by material degradation of the concrete or by the cracks that can be propagated during the life span of the given structure. Moreover, using a logistic function to classify the integrity of structure avoids the expensive learning step in the existing damage detection approaches, namely, using the modern machine and deep learning methods. The findings of this study look very promising when applied to other types of cantilever structures, such as the poles that support the power transmission lines, antenna masts, chimneys, and wind turbines. KW - Fahrleitung KW - Catenary poles KW - SHM KW - Model-free status monitoring KW - Sigmoid function KW - High-speed electric train KW - Schaden KW - OA-Publikationsfonds2021 Y1 - 2021 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:gbv:wim2-20211011-45212 UR - https://www.sciencedirect.com/science/article/pii/S2590123021000906?via%3Dihub VL - 2021 IS - volume 12, article 100289 SP - 1 EP - 8 PB - Elsevier CY - Amsterdam ER - TY - JOUR A1 - Alkam, Feras A1 - Lahmer, Tom T1 - Eigenfrequency-Based Bayesian Approach for Damage Identification in Catenary Poles JF - Infrastructures N2 - This study proposes an efficient Bayesian, frequency-based damage identification approach to identify damages in cantilever structures with an acceptable error rate, even at high noise levels. The catenary poles of electric high-speed train systems were selected as a realistic case study to cover the objectives of this study. Compared to other frequency-based damage detection approaches described in the literature, the proposed approach is efficiently able to detect damages in cantilever structures to higher levels of damage detection, namely identifying both the damage location and severity using a low-cost structural health monitoring (SHM) system with a limited number of sensors; for example, accelerometers. The integration of Bayesian inference, as a stochastic framework, in the proposed approach, makes it possible to utilize the benefit of data fusion in merging the informative data from multiple damage features, which increases the quality and accuracy of the results. The findings provide the decision-maker with the information required to manage the maintenance, repair, or replacement procedures. KW - Fahrleitung KW - Schaden KW - Fahrleitungsmast KW - Schadenserkennung KW - vibration-based damage identification KW - Bayesian inference Y1 - 2021 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:gbv:wim2-20210510-44256 UR - https://www.mdpi.com/2412-3811/6/4/57 VL - 2021 IS - Volume 6, issue 4, article 57 SP - 1 EP - 19 PB - MDPI CY - Basel ER - TY - THES A1 - Alkam, Feras T1 - Vibration-based Monitoring of Concrete Catenary Poles using Bayesian Inference N2 - This work presents a robust status monitoring approach for detecting damage in cantilever structures based on logistic functions. Also, a stochastic damage identification approach based on changes of eigenfrequencies is proposed. The proposed algorithms are verified using catenary poles of electrified railways track. The proposed damage features overcome the limitation of frequency-based damage identification methods available in the literature, which are valid to detect damage in structures to Level 1 only. Changes in eigenfrequencies of cantilever structures are enough to identify possible local damage at Level 3, i.e., to cover damage detection, localization, and quantification. The proposed algorithms identified the damage with relatively small errors, even at a high noise level. KW - Parameteridentifikation KW - Bayesian Inference, Uncertainty Quantification KW - Inverse Problems KW - Damage Identification KW - Concrete catenary pole KW - SHM KW - Inverse Probleme KW - Bayes’schen Inferenz KW - Unschärfequantifizierung KW - Schadenerkennung KW - Oberleitungsmasten Y1 - 2021 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:gbv:wim2-20210526-44338 UR - https://asw-verlage.de/katalog/vibration_based_monitoring_of_co-2363.html VL - 2021 PB - Bauhaus-Universitätsverlag CY - Weimar ER - TY - THES A1 - Alabassy, Mohamed Said Helmy T1 - Automated Approach for Building Information Modelling of Crack Damages via Image Segmentation and Image-based 3D Reconstruction N2 - As machine vision-based inspection methods in the field of Structural Health Monitoring (SHM) continue to advance, the need for integrating resulting inspection and maintenance data into a centralised building information model for structures notably grows. Consequently, the modelling of found damages based on those images in a streamlined automated manner becomes increasingly important, not just for saving time and money spent on updating the model to include the latest information gathered through each inspection, but also to easily visualise them, provide all stakeholders involved with a comprehensive digital representation containing all the necessary information to fully understand the structure’s current condition, keep track of any progressing deterioration, estimate the reduced load bearing capacity of the damaged element in the model or simulate the propagation of cracks to make well-informed decisions interactively and facilitate maintenance actions that optimally extend the service life of the structure. Though significant progress has been recently made in information modelling of damages, the current devised methods for the geometrical modelling approach are cumbersome and time consuming to implement in a full-scale model. For crack damages, an approach for a feasible automated image-based modelling is proposed utilising neural networks, classical computer vision and computational geometry techniques with the aim of creating valid shapes to be introduced into the information model, including related semantic properties and attributes from inspection data (e.g., width, depth, length, date, etc.). The creation of such models opens the door for further possible uses ranging from more accurate structural analysis possibilities to simulation of damage propagation in model elements, estimating deterioration rates and allows for better documentation, data sharing, and realistic visualisation of damages in a 3D model. KW - Building Information Modeling KW - BIM KW - IFC KW - Damage Information Modelling KW - Cracks Segmentation KW - Cracks 3D Modelling KW - Netscape Internet Foundation Classes Y1 - 2021 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:gbv:wim2-20230818-64162 ER - TY - THES A1 - Al Khatib, Khalid T1 - Computational Analysis of Argumentation Strategies N2 - The computational analysis of argumentation strategies is substantial for many downstream applications. It is required for nearly all kinds of text synthesis, writing assistance, and dialogue-management tools. While various tasks have been tackled in the area of computational argumentation, such as argumentation mining and quality assessment, the task of the computational analysis of argumentation strategies in texts has so far been overlooked. This thesis principally approaches the analysis of the strategies manifested in the persuasive argumentative discourses that aim for persuasion as well as in the deliberative argumentative discourses that aim for consensus. To this end, the thesis presents a novel view of argumentation strategies for the above two goals. Based on this view, new models for pragmatic and stylistic argument attributes are proposed, new methods for the identification of the modelled attributes have been developed, and a new set of strategy principles in texts according to the identified attributes is presented and explored. Overall, the thesis contributes to the theory, data, method, and evaluation aspects of the analysis of argumentation strategies. The models, methods, and principles developed and explored in this thesis can be regarded as essential for promoting the applications mentioned above, among others. KW - Argumentation KW - Natürliche Sprache KW - Argumentation Strategies KW - Sprachverarbeitung KW - Natural Language Processing KW - Computational Argumentation Y1 - 2021 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:gbv:wim2-20210719-44612 ER - TY - THES A1 - Adler, Maria T1 - Energiedissipation durch Fügestellendämpfung in Leichtbauanwendungen N2 - In vielen Leichtbauanwendungen ist der begrenzende Faktor die Schwingungsanfälligkeit der Bauteile. Eine Möglichkeit der Begrenzung von Schwingungsamplituden ist der gezielte Einsatz von Reibungsdämpfung in Leichtbaustrukturen. In dieser Arbeit wird der Einfluss dieser Art von Energiedissipation auf Leichtmetallstrukturen sowie topologieoptimierte Bauteil untersucht. Betrachtet werden dabei die Positionierung, Dimensionierung sowie die Reibeigenschaften dissipativer Elemente. KW - Leichtbau KW - Reibung KW - Dämpfung KW - Topologieoptimierung KW - Fügestellendämpfung Y1 - 2021 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:gbv:wim2-20210316-43949 ER - TY - BOOK ED - Czolbe, Fabian ED - Pfleiderer, Martin T1 - Klangwelten gestalten. Zur Aktualität des Bauhauses in Sound Design und auditiver Stadtplanung N2 - Die Gestaltung von Klangwelten ist in den letzten Jahrzehnten in den Fokus von Stadtplanern und Architekten, Produkt-Designern und Musikproduzenten, aber auch der historischen und kulturwissenschaftlichen Forschung gerückt. Der Tagungsband versteht sich als ein Beitrag zu diesem neuen Praxis- und Forschungsfeld. Er will zugleich Bezugspunkte zu Konzepten des Bauhauses als einem historischen Vorläufer aufzeigen. KW - Sound Design KW - Musik KW - Bauhaus Y1 - 2021 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:gbv:wim2-20210219-42808 SN - 978-3-96729-089-9 VL - 2021 PB - Mensch und Buch Verlag CY - Berlin ER -