@phdthesis{Elazzazy, author = {Elazzazy, Mohamed}, title = {The Garden Suburbs of Cairo. A morphological urban analysis of Zamālik, Ma'ādī, and Heliopolis}, doi = {10.25643/bauhaus-universitaet.4149}, url = {http://nbn-resolving.de/urn:nbn:de:gbv:wim2-20200506-41491}, school = {Bauhaus-Universit{\"a}t Weimar}, pages = {222}, abstract = {During the British occupation of Egypt in the beginning of the 20th century, several suburban developments were established on the periphery of the city of Cairo. These initially attracted the small British community and later foreigners and Egyptians, mainly from the elite community. These suburban developments, including Ma'ādī, Zamālik, Heliopolis, Qubbah-Gardens, and Garden City, became the fashionable residential quarters of Cairo. Until now, some of these areas still represent the distinguishable residential settlements of the city. Ma'ādī, Zamālik, and Heliopolis specifically are nostalgically appropriated in the design of recent suburban developments around Greater Cairo. Some of the 20th century suburban developments around Cairo are labeled or described as "garden cities." During the early 20th century, two thriving British town planning movements emerged, namely, the garden city movement and the garden suburb movement. This study investigates the hypothesis that these suburban developments, are indeed "garden suburbs" like the British movement, despite that few are labeled or described as "garden cities,". Although several studies have examined the historical development of such settlements, their relation, however, to the British planning movements and their transfer process received little attention from planning historians. Few studies also analyze the urban design aspects that made these suburban developments distinguishable since their foundation and until today. To guide the validity of this study's hypothesis, a set of research questions are formulated: (1) What is the difference between the garden city and the garden suburb movements? (2) How were the British planning movements transferred to Egypt? (3) What are the urban design aspects that makes these suburban developments distinguishable as garden suburbs? To answer these research questions, a historical morphological urban analysis is conducted through case studies. The study first studies the difference between the garden city and the garden suburb movements, mainly in Britain, through the analysis of publications on the promoter of both movements: for the garden city, E. Howards' book "The Garden City of Tomorrow," published in 1902, and for the garden suburb, R. Unwin's books "Town Planning in Practice," published in 1909, and "Nothing Gained from Overcrowding," published in 1912. Then a morphological urban analysis of Letchworth Garden City and Brentham Garden Suburb, considered the first examples of each movement, is conducted. In order to analyze the transfer process, the study adopts M. Volait and J. Nasr's theory on transporting planning, through investigating the authority in power responsible for the establishment of these suburban developments. This is followed by the morphological urban analysis of three suburban developments around Cairo, namely, Zamālik, Ma'ādī, and Heliopolis. The morphological analysis focuses on the background of their establishment, authority in power responsible for the development, design principles, urban context, street typology, residential block typology, social infrastructure, and social target group. Finally, the study compares between Brentham, Letchworth, Zamālik, Ma'ādī, and Heliopolis. The comparative analysis aims to highlight the differences between the studied cases of Cairo and how they are different from or alike the British movements. This study concludes that the suburban developments around Cairo during the British occupation, are in fact garden suburbs, despite that some are being described or labeled as garden city. This movement was exported via urban land development companies with foreign European capital, rather than via colonial dominance. It finally highlights a set of urban design aspects that distinguish them as garden suburbs of Cairo. This study hopes to support future conservation plan of these areas and the design of future suburban developments.}, subject = {Kairo}, language = {en} } @phdthesis{Doering, author = {Doering, Chris}, title = {Die Informationsarchitektur der kommunalen Energiewende}, doi = {10.25643/bauhaus-universitaet.4051}, url = {http://nbn-resolving.de/urn:nbn:de:gbv:wim2-20191219-40514}, school = {Bauhaus-Universit{\"a}t Weimar}, pages = {278}, abstract = {Die kommunale Energiewende stellt die beteiligten Akteure vor große Herausforderungen: Auf Grundlage strukturierter Daten sollen Maßnahmen
 f{\"u}r eine nachhaltige Infrastruktur geplant und umgesetzt werden. Oft fehlt
 den Beteiligten jedoch das n{\"o}tige Wissen {\"u}ber die lokalen Potentiale und Rahmenbedingungen—und an geeigneten Methoden der Informationsvermittlung. Gegenstand dieser Arbeit ist die Analyse der Planungsstrukturen und der Entwurf eines visuellen Informationssystems. Mit der vorliegenden Untersuchung wird gezeigt, wie mit Hilfe von Befragungen, partizipativen Visualisierungen, fiktionalen Szenarien und der systematischen Anwendung visueller Variablen eine fundierte Grundlage geschaffen werden kann f{\"u}r eine nutzerorientierte Gestaltung.}, subject = {Design}, language = {de} } @phdthesis{Elrasoul, author = {Elrasoul, Riham}, title = {Designing Urban National Memory}, doi = {10.25643/bauhaus-universitaet.4048}, url = {http://nbn-resolving.de/urn:nbn:de:gbv:wim2-20191212-40489}, school = {Bauhaus-Universit{\"a}t Weimar}, abstract = {The study of memory, architecture, and urban space has been the interest ‎of ‎researchers ‎from the diverse fields around the world due to, the significance of dealing ‎with ‎memories ‎especially after the tragedy of the Second World War. Nations in Europe has chosen ‎not to ‎neglect ‎their past, moreover, overcoming it by strengthening the national identity. An ‎approach was clear in ‎the literature, art, further in the way of rebuilding their cities; that mainly ‎has reflected on the ‎value of urban spaces and their role in narrating the country's national ‎memory. Thanks to this ‎approach, which has supported the post-war European nations to invite ‎to an act of ‎ forgiveness rather than to forget. ‎ On the contrary, memory, in relation to architecture is a form of knowledge has been ‎neglected in Egypt, especially during the previous decades after the declaration of independence ‎from the colonial power, and since 1952 revolution. Recently, a rising debate about Egypt ‎national history and the need to renationalize the Egyptian historical consciousness has rapidly ‎grown up, due to the political transformation has occurred because of the 25th uprising, 2011, ‎which unveiled the power of public spaces in constituting the nation thoughts, especially Tahrir ‎square.‎ At the same time, this has unveiled the results of neglecting the past instead of overcoming it; unveiled a present carries the danger of conflict and repeating previous mistakes. Researchers, historians, politicians, governmental organization, have ‎worked in the purpose of revisiting the historical information, and have tried to document the ‎current transformation of the 25th uprising. There was a public demand for redesigning Tahrir square to reflect the ‎memory of the uprising as a symbol of the power of the public. However, after eight years, those ‎memories have faded as if the 25th uprising has never happened. ‎ Those circumstances are very relevant to the gap between urban design and the art of ‎memory-work, in the scientific field. Few studies in Egypt conducted the concept of memory in ‎relation to urban spaces, however, the matter requires more attention, to associate the need for renationalizing Egypt ‎memory, with viewing urban space as a mean of narrating the country's national memory and ‎reflecting the citizens' current thoughts, as a try of nearing the distances between ‎competing ‎narratives. Therefore, the research aims at developing a methodological framework that should ‎contribute to renationalizing memory through urban space. Further, benefiting from the German experience by investigating lessons to learn. That is based on the hypothesis that, although there is no fixed formula for all countries to renationalize the historical ‎consciousness of memory through urban spaces, lessons to be learned from Germany experience ‎could be a driving dimension when designing Egyptian urban spaces with a concept of memory ‎as an essential factor. To guide the validity of the study's hypothesis, a set of research questions are thus ‎formulated: Starting from why memory is an essential factor when designing urban spaces? ‎Regarding Egypt national memory, how it was constituted through history and how to read its ‎representation on urban spaces? Also, the study quests the means of nationalizing memory ‎through urban spaces? And What are the learned lessons from the German experience?‎ The study tries to answer those questions. Via an inductive ‎analytical ‎methodology ‎which ‎moves from the gap of knowledge and from a particular situation ‎in Egypt, to study the German ‎experience in renationalizing the concept of memory through urban spaces.‎ ‎ Within the scope of the study, exploring Egypt prevailing narratives and the inherited ‎concepts which influenced the national memory is essential. Moreover, the research develops ‎analytical political psychosocial model that could help reading memories in urban spaces, ‎memory's actors, and memory influences. To validate this model, case studies are analysed in ‎light of the concluded aspects. Consequently, the expected result is to infer broad general ‎learned ‎lessons for the Egyptian case. ‎ Research findings and conclusions answer the research questions, interpret literature ‎review, recommend some guide points to three target groups: first, practice field; to encourage ‎designers to value the national and collective memories when designing urban spaces. Second, to ‎ask policymakers to take the public participation into consideration, when taking decisions related to urban ‎development. Third, the thesis recommends future researches of urban memory that connect ‎theoretical information with the practice field. ‎ Finally, enhancing the memory-work in relation to the national narrative, conveying a meaningful message, when ‎designing urban spaces could encourage citizens to learn, to interact, and to dissolve boundaries ‎between the competing narratives in post-conflict societies.‎}, subject = {Erinnerung}, language = {en} } @phdthesis{Tasch, author = {Tasch, Alexander}, title = {Reaktive Cu-Fe-Al-Mn-Oxidkeramiken f{\"u}r die Sauerstoffseparation aus der Luft}, doi = {10.25643/bauhaus-universitaet.4041}, url = {http://nbn-resolving.de/urn:nbn:de:gbv:wim2-20191209-40414}, school = {Bauhaus-Universit{\"a}t Weimar}, abstract = {Die Gase Sauerstoff und Stickstoff werden f{\"u}r eine Vielzahl an technischen, industriellen, biologischen und medizinischen Einsatzzwecken ben{\"o}tigt. So liegen Anwendungsgebiete dieser Gase neben der klassischen metallverarbeitenden und der chemischen Industrie bei Sauerstoff vor allem in der Medizin, Verbrennungs- und Kl{\"a}ranlagenoptimierung sowie der Fischzucht und bei Stickstoff als Schutz- beziehungsweise Inertgas in der Kunststoffindustrie, der Luft- und Raumfahrt sowie dem Brandschutz. Die Bereitstellung der Gase Sauerstoff und Stickstoff wird nahezu ausschließlich durch die Abtrennung aus der Umgebungsluft realisiert, welche aus ca. 78 Vol.-\% Stickstoff, 21 Vol.-\% Sauerstoff und 1 Vol.-\% Spurengasen (Ar, CO2, Ne, He, ...) besteht. Am Markt etablierte Verfahren der Luftzerlegung sind das Linde-, das PSA- (pressure swing adsorption/Druckwechseladsorption) oder verschiedene Membran-Verfahren. Hierdurch werden die ben{\"o}tigten Gase entweder direkt vor Ort beim Verbraucher erzeugt (PSA- und Polymer-Membranverfahren: geringe Reinheiten) oder zentral in großen Anlagen hergestellt (Linde-Verfahren: hohe Reinheiten) und anschließend zum Verbraucher in Form von Flaschen- oder Tankgasen geliefert (Tansportkosten). F{\"u}r kleinere Verbraucher mit hohen Anspr{\"u}chen an die Reinheit des ben{\"o}tigten Sauerstoffs beziehungsweise Stickstoffs ergibt sich nur die M{\"o}glichkeit, die Gase als kostenintensive Transportgase zentraler Gaseversorger zu beziehen und sich somit in eine Abh{\"a}ngigkeit (Liefervertr{\"a}ge, Flaschen-/Tankmieten, ...) zu diesen zu begeben sowie eine eigene Lagerhaltung f{\"u}r die ben{\"o}tigten Gase (Mehraufwand, Lagerkosten, Platzbedarf) zu betreiben. Ziel dieser Arbeit ist es, keramische Material-Systeme auf Basis chemischer Hochtemperatur-Reaktionen als Reaktive Oxidkeramiken zu entwickeln und diese hinsichtlich eines m{\"o}glichen Einsatzes f{\"u}r die Sauerstoffseparation in neuartigen Luftzerlegungsanlagen zu untersuchen. Derartige Anlagen sollen in ihrem Prinzip an die regenerative Sauerstoffseparation angelehnt sein und in ihren Reaktoren die Reaktiven Oxidkeramiken als Festbett-Material abwechselnd mit Luft be- und Vakuum oder O2-armen Atmosph{\"a}ren entladen. Die Verwendung Reaktiver Oxidkeramiken, welche im Vergleich zu den bisherigen Materialien h{\"o}here Sauerstoffaustauschmengen und -raten bei gleichzeitig hoher Lebensdauer und Korrosionsbest{\"a}ndigkeit sowie relativ einfacher Handhabe aufweisen w{\"u}rden, soll ein Schritt in Richtung einer effizienten alternativen Luftzerlegungstechnologie sein. Mit den Reaktiven Oxidkeramiken in einer Luftzerlegungsanlage sollte es im besten Fall m{\"o}glich sein, in kleinen Anlagen sehr reinen Sauerstoff und zugleich sauerstofffreies Inertgas zu erzeugen sowie eine Sauerstoffan- oder -abreicherung von Luft, Prozess- oder Abgasen zu generieren. Somit bes{\"a}ße eine solche, auf Reaktiven Oxidkeramiken basierende Technologie sehr weit gef{\"a}cherte Einsatzgebiete und demzufolge ein enormes wirtschaftliches Potential.}, subject = {Luftzerlegung}, language = {de} } @phdthesis{Hossain, author = {Hossain, Md Naim}, title = {Isogeometric analysis based on Geometry Independent Field approximaTion (GIFT) and Polynomial Splines over Hierarchical T-meshes}, doi = {10.25643/bauhaus-universitaet.4037}, url = {http://nbn-resolving.de/urn:nbn:de:gbv:wim2-20191129-40376}, school = {Bauhaus-Universit{\"a}t Weimar}, pages = {157}, abstract = {This thesis addresses an adaptive higher-order method based on a Geometry Independent Field approximatTion(GIFT) of polynomial/rationals plines over hierarchical T-meshes(PHT/RHT-splines). In isogeometric analysis, basis functions used for constructing geometric models in computer-aided design(CAD) are also employed to discretize the partial differential equations(PDEs) for numerical analysis. Non-uniform rational B-Splines(NURBS) are the most commonly used basis functions in CAD. However, they may not be ideal for numerical analysis where local refinement is required. The alternative method GIFT deploys different splines for geometry and numerical analysis. NURBS are utilized for the geometry representation, while for the field solution, PHT/RHT-splines are used. PHT-splines not only inherit the useful properties of B-splines and NURBS, but also possess the capabilities of local refinement and hierarchical structure. The smooth basis function properties of PHT-splines make them suitable for analysis purposes. While most problems considered in isogeometric analysis can be solved efficiently when the solution is smooth, many non-trivial problems have rough solutions. For example, this can be caused by the presence of re-entrant corners in the domain. For such problems, a tensor-product basis (as in the case of NURBS) is less suitable for resolving the singularities that appear since refinement propagates throughout the computational domain. Hierarchical bases and local refinement (as in the case of PHT-splines) allow for a more efficient way to resolve these singularities by adding more degrees of freedom where they are necessary. In order to drive the adaptive refinement, an efficient recovery-based error estimator is proposed in this thesis. The estimator produces a recovery solution which is a more accurate approximation than the computed numerical solution. Several two- and three-dimensional numerical investigations with PHT-splines of higher order and continuity prove that the proposed method is capable of obtaining results with higher accuracy, better convergence, fewer degrees of freedom and less computational cost than NURBS for smooth solution problems. The adaptive GIFT method utilizing PHT-splines with the recovery-based error estimator is used for solutions with discontinuities or singularities where adaptive local refinement in particular domains of interest achieves higher accuracy with fewer degrees of freedom. This method also proves that it can handle complicated multi-patch domains for two- and three-dimensional problems outperforming uniform refinement in terms of degrees of freedom and computational cost.}, subject = {Finite-Elemente-Methode}, language = {en} } @phdthesis{Chen, author = {Chen, Na}, title = {A Balance between Ideals and Reality — Establishing and Evaluating a Resilient City Indicator System for Central Chinese Cities}, doi = {10.25643/bauhaus-universitaet.4030}, url = {http://nbn-resolving.de/urn:nbn:de:gbv:wim2-20191121-40309}, school = {Bauhaus-Universit{\"a}t Weimar}, pages = {212}, abstract = {Recent years have seen a gradual shift in focus of international policies from a national and regional perspective to that of cities, a shift which is closely related to the rapid urbanization of developing countries. As revealed in the 2011 Revision of the World Urbanization Prospects published by the United Nations, 51\% of the global population (approximately 3.6 billion people) lives in cities. The report predicts that by 2050, the world's urban population will increase by 2.3 billion, making up 68\% of the population. The growth of urbanization in the next few decades is expected to primarily come from developing countries, one third of which will be in China and India. With rapid urbanization and the ongoing growth of mega cities, cities must become increasingly resilient and intelligent to cope with numerous challenges and crises like droughts and floods arising from extreme climate, destruction brought by severe natural disasters, and aggregated social contradictions resulting from economic crises. All cities face the urban development dynamics and uncertainties arising from these problems. Under such circumstances, cities are considered the critical path from crisis to prosperity, so scholars and organizations have proposed the construction of "resilient cities." On the one hand, this theory emphasizes cities' defenses and buffering capacity against disasters, crises and uncertainties, as well as recovery after destruction; on the other hand, it highlights the learning capacity of urban systems, identification of opportunities amid challenges, and maintenance of development vitality. Some scholars even believe that urban resilience is a powerful supplement to sustainable development. Hence, resilience assessment has become the latest and most important perspective for evaluating the development and crisis defense capacity of cities. Rather than a general abstract concept, urban resilience is a comprehensive measurement of a city's level of development. The dynamic development of problems is reflected through quantitative indicators and appraisal systems not only from the perspective of academic research, but also governmental policy, so as to scientifically guide development, and measure and compare cities' development levels. Although international scholars have proposed quantitative methods for urban resilience assessment, they are however insufficiently systematic and regionally adaptive for China's current urban development needs. On the basis of comparative study on European and North American resilient city theories, therefore, this paper puts forwards a theoretical framework for resilient city systems consistent with China's national conditions in light of economic development pressure, natural resource depletion, pollution, and other salient development crises in China. The key factors influencing urban resilience are taken into full consideration; expert appraisal is conducted based on the Delphi Method and the analytic hierarchy process (AHP) to design an extensible and updatable resilient city evaluation system which is sufficiently systematic, geographically adaptable, and sustainable for China's current urban development needs. Finally, Changsha is taken as the main case for empirical study on comprehensive evaluation of similar cities in Central China to improve the indicator system.}, subject = {Stadtplanung}, language = {en} } @phdthesis{Sidjimovska, author = {Sidjimovska, Ivana}, title = {Recounting Skopje. Skopje 2014: Symbolic and Citizens' Narratives}, doi = {10.25643/bauhaus-universitaet.4025}, url = {http://nbn-resolving.de/urn:nbn:de:gbv:wim2-20191119-40256}, school = {Bauhaus-Universit{\"a}t Weimar}, pages = {363}, abstract = {Focusing on the neoliberal symbolic urban reconstruction of the Macedonian capital, known as "Skopje 2014", the PhD work deals with urban space production through storytelling. Embracing the criticism put forward in the political, cultural and social debates that have spun around Skopje's reconstruction, the artistic-based research sought to relate and analyze the symbolic narratives of "Skopje 2014" and the vernacular and civic narratives of Skopje and locate overlapping, divergent, complementary or conflictual aspects of their respective narrative structures. Informed by subjective citizens' stories and experiences of the urban as well as binaural sonic observations of the city, the research findings were presented in the form of an interactive audio guided walk through the city. The thesis is organized in three chapters, preceded by an INTRODUCTION and followed by a CONCLUSION. CHAPTER ONE sets the theoretical context, presents the case study "Skopje 2014", and discusses the research design. The audio guided walk is presented in CHAPTER TWO. Its content consists of five tracks, or subchapters, conceptualized and named as five different aspects of the city: THE MODERNIST CITY, THE FEMALE CITY, THE MEMORY CITY, THE POSTCOMMUNIST CITY and THE TOURIST CITY, according to the discourses related to these tracks. CHAPTER THREE, the EPILOGUE, is the final discussion of the research project, in which several meta-conclusions are drawn.}, subject = {Stadtumbau}, language = {en} } @phdthesis{Grossmann, author = {Grossmann, Albert}, title = {Sicherheitskonzept zur Ber{\"u}cksichtigung von Korrosion an Gashochdruckleitungen aus St{\"a}hlen}, doi = {10.25643/bauhaus-universitaet.4019}, url = {http://nbn-resolving.de/urn:nbn:de:gbv:wim2-20191113-40199}, school = {Bauhaus-Universit{\"a}t Weimar}, pages = {184}, abstract = {Gashochdruckleitungen aus Stahl werden mit Hilfe eines deterministischen Sicherheitskonzeptes bemessen. Im unver{\"a}nderten Bemessungszustand und im bestimmungsgem{\"a}ßem Betrieb ist die statische Tragf{\"a}higkeit der Gashochdruckleitungen gegeben. Mit den Jahren unterliegen Gashochdruckleitungen aus Stahl geometrischen Ver{\"a}nderungen, die h{\"a}ufig durch Korrosion hervorgerufen werden. Die Beurteilung der statischen Tragf{\"a}higkeit erfolgt dann unter Ber{\"u}cksichtigung dieser geometrischen {\"A}nderung. Deterministische Sicherheitsbeiwerte der Bemessung neuer Gashochdruckleitungen k{\"o}nnen f{\"u}r die Bemessung bestehender korrosionsgesch{\"a}digter Gashochdruckleitungen nicht herangezogen werden, da diese einen definierten Beanspruchungs- und Geometriezustand unterstellen, welcher durch den geometrischen Einfluss der Korrosion so nicht mehr besteht. Die Arbeit befasst sich mit der Ermittlung deterministischer Sicherheitsbeiwerte f{\"u}r die Bemessung korrosionsgesch{\"a}digter Gashochdruckleitungen auf Basis von Versagenswahrscheinlichkeiten und stellt ein Anwendungskonzept zu deren Nutzung vor.}, subject = {Gashochdruckleitungen}, language = {de} } @phdthesis{Shahraki, author = {Shahraki, Mojtaba}, title = {Numerical Analysis of Soil Behavior and Stone Columns Effects on the Railway Track}, doi = {10.25643/bauhaus-universitaet.4015}, url = {http://nbn-resolving.de/urn:nbn:de:gbv:wim2-20191111-40159}, school = {Bauhaus-Universit{\"a}t Weimar}, abstract = {Railway systems are highly competitive compared with other means of transportation because of their distinct advantages in speed, convenience and safety. Therefore, the demand for railway transportation is increasing around the world. Constructing railway tracks and related engineering structures in areas with loose or soft cohesive subgrade usually leads to problems, such as excessive settlement, deformation and instability. Several remedies have been proposed to avoid or reduce such problems, including the replacement of soft soil and the construction of piles or stone columns. This thesis aims to expand the geotechnical knowledge of how to improve subgrade ballasted railway tracks, using stone columns and numerical modeling for the railway infrastructure. Three aspects are considered: i) railway track dynamics modeling and validation by field measurements, ii) modeling and parametric studies on stone columns, and iii) studies on the linear and non-linear behavior of stone columns under the dynamic load of trains. The first step of this research was to develop a reliable numerical model of a railway track. The finite element method in a time domain was used for either a 2D plane strain or 3D analysis. Individual methods for modeling a train load in 2D and 3D were implemented and are discussed in this thesis. The developed loading method was validated with three different railway tracks using obtained vibration measurements. Later, these numerical models were used to analyze the influence of stone column length and train speed in the stress field. The performance of the treated ground depends on various parameters, such as the strength of stone columns, spacing, length and diameter of the columns. Therefore, the second step was devoted to a parameter study of stone columns as a unit cell with an axisymmetric condition. The results showed that even short stone columns were effective for settlement reduction, and area of replacement was the main influential parameter in their performance. The third part of this thesis focuses on a hypothetical railway-track response to the passage of various train speeds and the influence of stone-column length. The stress-strain response of subgrade is analyzed under either an elastic-perfectly plastic or advanced constitutive model. The non-linear soil response in the finite element method and the impact of train speed and stone column length on railway tracks are also evaluated. Moreover, the reductions of induced vibration - in both a horizontal and a vertical direction - after improvement are investigated.}, subject = {Eisenbahn}, language = {en} } @phdthesis{Krueger, author = {Kr{\"u}ger, Arvid}, title = {Neue Steuerungsmodelle der Stadterneuerung - … und daraus folgende Anforderungen an die St{\"a}dtebauf{\"o}rderung, die Kommunen und die gemeinn{\"u}tzige Wohnungswirtschaft}, doi = {10.25643/bauhaus-universitaet.3997}, url = {http://nbn-resolving.de/urn:nbn:de:gbv:wim2-20191105-39976}, school = {Bauhaus-Universit{\"a}t Weimar}, pages = {384}, abstract = {Großsiedlungen sind nicht nur ein Erbe der Moderne, sondern seit {\"u}ber drei Jahrzehnten Gegenstand der Stadterneuerung. Dieses Buch er{\"o}rtert, was eine heute „normale" Großsiedlung stadtplanerisch ben{\"o}tigt und welche stadtentwicklungs- als auch wohnungspolitisch gesteuerten Ressourcen in einer integrierten Planungssteuerung geb{\"u}ndelt werden sollten. Dabei wird das grunds{\"a}tzliche Planungsinstrument des Quartiersmanagements aktualisiert - {\"u}ber den Gegenstand Großsiedlungen hinaus.}, subject = {Stadtplanung}, language = {de} } @phdthesis{Grossmann, author = {Grossmann, Albert}, title = {Sicherheitskonzept zur Ber{\"u}cksichtigung von Korrosion an Gashochdruckleitungen aus St{\"a}hlen}, doi = {10.25643/bauhaus-universitaet.4003}, url = {http://nbn-resolving.de/urn:nbn:de:gbv:wim2-20191021-40034}, school = {Bauhaus-Universit{\"a}t Weimar}, pages = {184}, abstract = {Gashochdruckleitungen aus Stahl werden mit Hilfe eines deterministischen Sicherheitskonzeptes bemessen. Im unver{\"a}nderten Bemessungszustand und im bestimmungsgem{\"a}ßem Betrieb ist die statische Tragf{\"a}higkeit der Gashochdruckleitungen gegeben. Mit den Jahren unterliegen Gashochdruckleitungen aus Stahl geometrischen Ver{\"a}nderungen, die h{\"a}ufig durch Korrosion hervorgerufen werden. Die Beurteilung der statischen Tragf{\"a}higkeit erfolgt dann unter Ber{\"u}cksichtigung dieser geometrischen {\"A}nderung. Deterministische Sicherheitsbeiwerte der Bemessung neuer Gashochdruckleitungen k{\"o}nnen f{\"u}r die Bemessung bestehender korrosionsgesch{\"a}digter Gashochdruckleitungen nicht herangezogen werden, da diese einen definierten Beanspruchungs- und Geometriezustand unterstellen, welcher durch den geometrischen Einfluss der Korrosion so nicht mehr besteht. Die Arbeit befasst sich mit der Ermittlung deterministischer Sicherheitsbeiwerte f{\"u}r die Bemessung korrosionsgesch{\"a}digter Gashochdruckleitungen auf Basis von Versagenswahrscheinlichkeiten und stellt ein Anwendungskonzept zu deren Nutzung vor.}, subject = {Sicherheit}, language = {de} } @phdthesis{Hasche, author = {Hasche, Katja}, title = {Substanz, Struktur oder Bild? Denkmalpflegerische Erfassung von Siedlungen und Wohnanlagen der 1950er bis 1980er Jahre in Westeuropa}, doi = {10.25643/bauhaus-universitaet.3998}, url = {http://nbn-resolving.de/urn:nbn:de:gbv:wim2-20191011-39983}, school = {Bauhaus-Universit{\"a}t Weimar}, pages = {199}, abstract = {Die Dissertation umfasst eine vertiefende Untersuchung der denkmalpflegerischen Erfassung von Siedlungen und Wohnanlagen als eine der wichtigsten und umfangreichsten Bautypologien der 1950er bis 1980er Jahre in Westeuropa. Die Besch{\"a}ftigung mit Bauten der 1950er bis 1980er Jahre f{\"u}hrt bei Denkmalpflegern, Architekten, Bewohnern und Politikern immer wieder zu {\"U}berlegungen, ob diese besondere Erfassungs- und Erhaltungsstrategien erfordern. Dabei wirft die Typologie des Siedlungsbaus besondere Fragen auf, da sie neben architektonischen Aspekten auch st{\"a}dtebauliche, landschaftsplanerische und sozialwissenschaftliche Bedeutungsebenen umfasst. Nicht zuletzt sind Siedlungen der 1950er bis 1980er Jahre aus denkmalpflegerischer Sicht h{\"a}ufig stark gef{\"a}hrdet. Obwohl die meisten Siedlungen noch nicht ausreichend kunsthistorisch gew{\"u}rdigt und erfasst sind, unterliegen sie einem hohen Ver{\"a}nderungsdruck. Die teilweise enorme st{\"a}dtebauliche Dimension und Monofunktionalit{\"a}t der Anlagen, die h{\"a}ufig aufgrund von seriellen Bautypen und vorfabrizierten Elementen gleichf{\"o}rmige architektonische Gestaltung und eine Vernachl{\"a}ssigung im Bauunterhalt erschweren den Zugang zu dieser Baugattung. Gewandelte Wohnbed{\"u}rfnisse sowie bauphysikalische, energietechnische oder {\"a}sthetische Maßnahmen f{\"u}hren zur Ver{\"a}nderung der noch relativ jungen Bausubstanz. Zudem weisen Siedlungen der Nachkriegszeit aufgrund ihrer teilweise sehr großz{\"u}gigen Freiraumstruktur ein großes Potential zur Nachverdichtung auf. Die Auswahl der in dieser Arbeit untersuchten L{\"a}nder und Siedlungen ergab sich aus der Auswertung einer europaweiten Befragung von Denkmal{\"a}mtern sowie anschließend gef{\"u}hrten Gespr{\"a}chen mit Fachleuten. Die untersuchten 20 Siedlungen und Wohnanlagen repr{\"a}sentieren verschiedene L{\"a}nder (Deutschland, {\"O}sterreich, Schweiz, Frankreich, Niederlande, England) sowie Bauepochen und Siedlungstypologien, die von der Einfamilienhaussiedlung {\"u}ber Siedlungen mit gemischter Bautypologie hin zur Großsiedlung reichen. Anhand der unterschiedlichen Fallbeispiele wird aufgezeigt, inwiefern die jeweiligen L{\"a}nder, Bauepochen beziehungsweise Siedlungstypologien Einfluss auf die denkmalpflegerischen Erfassungsstrategien haben. Zusammenfassend l{\"a}sst sich res{\"u}mieren, dass die Gesetzesgrundlagen und Denkmalkriterien f{\"u}r eine denkmalpflegerische Erfassung von Bauten der 1950er bis 1980er Jahre in den meisten L{\"a}ndern konstant bleiben, w{\"a}hrend sich in den Bereichen Zeitpunkt, Auswahl und Einbindung der {\"O}ffentlichkeit eine Modifizierung oder zumindest eine Reflektion der bisherigen Strukturen abzeichnet. Sinnvoll und w{\"u}nschenswert erscheint dar{\"u}ber hinaus ein verst{\"a}rkter Austausch der Denkmalpflege {\"u}ber die nationalen Grenzen hinweg und ein gegenseitiges Lernen voneinander.}, subject = {Architektur}, language = {de} } @phdthesis{Steindorf, author = {Steindorf, Johanna}, title = {Speaking from Somewhere: Der Audio-Walk als k{\"u}nstlerische Praxis und Methode}, doi = {10.25643/bauhaus-universitaet.3993}, url = {http://nbn-resolving.de/urn:nbn:de:gbv:wim2-20190924-39930}, school = {Bauhaus-Universit{\"a}t Weimar}, pages = {245}, abstract = {In der vorliegenden Arbeit „Speaking from Somewhere: Der Audio-Walk als k{\"u}nstlerische Praxis und Methode" wird der Audio-Walk auf theoretischer und praktischer Basis untersucht. Der erste Teil widmet sich dem Audio-Walk als k{\"u}nstlerisches Format. Darin wird analysiert, wie dieses aufgebaut ist und welche Komponenten wie zusammenwirken, damit sich die Darbietung - und die daf{\"u}r charakteristisch intensive Wirkung - entfalten kann. Im zweiten Teil wird der Audio-Walk als experimentelle mobile Methode f{\"u}r die k{\"u}nstlerische Forschung betrachtet. Im Zentrum steht dabei die Frage, wie sich das k{\"u}nstlerische Format nutzen l{\"a}sst, um spezifische Fragestellungen an einen ausgew{\"a}hlten Personenkreis zu adressieren, der sich w{\"a}hrenddessen in einer inszenierten Situation befindet. Der Schwerpunkt liegt dabei auf Audio-Walk-Experimenten, die mit dieser Absicht entwickelt wurden. Als Fallbeispiel f{\"u}r die Methode dient dabei die Zusammenarbeit mit einer Gruppe k{\"u}rzlich nach Deutschland migrierter Frauen.}, subject = {Auff{\"u}hrung}, language = {de} } @phdthesis{Hasche, author = {Hasche, Katja}, title = {Substanz, Struktur oder Bild? Denkmalpflegerische Erfassung von Siedlungen und Wohnanlagen der 1950er bis 1980er Jahre in Westeuropa}, doi = {10.25643/bauhaus-universitaet.3992}, url = {http://nbn-resolving.de/urn:nbn:de:gbv:wim2-20190924-39921}, school = {Bauhaus-Universit{\"a}t Weimar}, pages = {201}, abstract = {Die Dissertation umfasst eine vertiefende Untersuchung der denkmalpflegerischen Erfassung von Siedlungen und Wohnanlagen als eine der wichtigsten und umfangreichsten Bautypologien der 1950er bis 1980er Jahre in Westeuropa. Die Besch{\"a}ftigung mit Bauten der 1950er bis 1980er Jahre f{\"u}hrt bei Denkmalpflegern, Architekten, Bewohnern und Politikern immer wieder zu {\"U}berlegungen, ob diese besondere Erfassungs- und Erhaltungsstrategien erfordern. Dabei wirft die Typologie des Siedlungsbaus besondere Fragen auf, da sie neben architektonischen Aspekten auch st{\"a}dtebauliche, landschaftsplanerische und sozialwissenschaftliche Bedeutungsebenen umfasst. Nicht zuletzt sind Siedlungen der 1950er bis 1980er Jahre aus denkmalpflegerischer Sicht h{\"a}ufig stark gef{\"a}hrdet. Obwohl die meisten Siedlungen noch nicht ausreichend kunsthistorisch gew{\"u}rdigt und erfasst sind, unterliegen sie einem hohen Ver{\"a}nderungsdruck. Die teilweise enorme st{\"a}dtebauliche Dimension und Monofunktionalit{\"a}t der Anlagen, die h{\"a}ufig aufgrund von seriellen Bautypen und vorfabrizierten Elementen gleichf{\"o}rmige architektonische Gestaltung und eine Vernachl{\"a}ssigung im Bauunterhalt erschweren den Zugang zu dieser Baugattung. Gewandelte Wohnbed{\"u}rfnisse sowie bauphysikalische, energietechnische oder {\"a}sthetische Maßnahmen f{\"u}hren zur Ver{\"a}nderung der noch relativ jungen Bausubstanz. Zudem weisen Siedlungen der Nachkriegszeit aufgrund ihrer teilweise sehr großz{\"u}gigen Freiraumstruktur ein großes Potential zur Nachverdichtung auf. Die Auswahl der in dieser Arbeit untersuchten L{\"a}nder und Siedlungen ergab sich aus der Auswertung einer europaweiten Befragung von Denkmal{\"a}mtern sowie anschließend gef{\"u}hrten Gespr{\"a}chen mit Fachleuten. Die untersuchten 20 Siedlungen und Wohnanlagen repr{\"a}sentieren verschiedene L{\"a}nder (Deutschland, {\"O}sterreich, Schweiz, Frankreich, Niederlande, England) sowie Bauepochen und Siedlungstypologien, die von der Einfamilienhaussiedlung {\"u}ber Siedlungen mit gemischter Bautypologie hin zur Großsiedlung reichen. Anhand der unterschiedlichen Fallbeispiele wird aufgezeigt, inwiefern die jeweiligen L{\"a}nder, Bauepochen beziehungsweise Siedlungstypologien Einfluss auf die denkmalpflegerischen Erfassungsstrategien haben. Zusammenfassend l{\"a}sst sich res{\"u}mieren, dass die Gesetzesgrundlagen und Denkmalkriterien f{\"u}r eine denkmalpflegerische Erfassung von Bauten der 1950er bis 1980er Jahre in den meisten L{\"a}ndern konstant bleiben, w{\"a}hrend sich in den Bereichen Zeitpunkt, Auswahl und Einbindung der {\"O}ffentlichkeit eine Modifizierung oder zumindest eine Reflektion der bisherigen Strukturen abzeichnet. Sinnvoll und w{\"u}nschenswert erscheint dar{\"u}ber hinaus ein verst{\"a}rkter Austausch der Denkmalpflege {\"u}ber die nationalen Grenzen hinweg und ein gegenseitiges Lernen voneinander.}, subject = {Architektur}, language = {de} } @phdthesis{Walther, author = {Walther, Franziska}, title = {{\"U}ber den Wirkungsanspruch von Illustratoren in literarischer Buchillustration: Eine diskurskritische und praxis-basierte Studie}, doi = {10.25643/bauhaus-universitaet.3988}, url = {http://nbn-resolving.de/urn:nbn:de:gbv:wim2-20190924-39888}, school = {Bauhaus-Universit{\"a}t Weimar}, pages = {576}, abstract = {Zum Begriff Illustration scheint ein Missverh{\"a}ltnis zwischen wissenschaftlicher Rezeption und praktischem Gegenstand vorzuliegen. Traditionell bezeichnet der Begriff Illustration ein Bild, das einen textlich vorangestellten Inhalt noch einmal visuell wiederholt und auf diesem Weg in einem Abbild verdoppelt. Traditionelle Illustration benennt also ein sekund{\"a}res, explizit von einem anderen Inhalt abh{\"a}ngiges Bild, das auch weggelassen werden k{\"o}nnte, ohne das Inhalt verloren geht. Genutzt wird dieser traditionelle Illustrationsbegriff heute unter anderem in den Forschungsfeldern der Kunstgeschichte, der Bildwissenschaften und der Literatur­wissenschaften. Aus der Perpektive der Praxis birgt der traditionelle Illustrationsbegriff ein grunds{\"a}tzliches Problem in sich. Er versucht, mit einer statischen Definition ein {\"a}ußerst lebendiges visuelles Ph{\"a}nomen unserer heutigen Zeit zu beschreiben. Professionelle Berufszeichner, die sogenannten Illustratorinnen und Illustratoren, kreieren heute Werke, die mit dem traditionellen Illustrations­begriff nicht mehr beschreibbar sind. Mehr noch, der traditionelle Illustrationsbegriff macht blind f{\"u}r diese Entwicklungen, die sich deshalb außerhalb des wissenschaft­lichen Diskurses abspielen. Die vorliegende Arbeit m{\"o}chte deshalb einen Blick auf den Zustand zeitgen{\"o}ssischer literarischer Buch­illustration werfen, um den Begriff der Illustration in seiner aktuellen Unsch{\"a}rfe zu pr{\"a}zisieren, zu erweitern und somit zu aktualisieren.}, subject = {Illustration}, language = {de} } @phdthesis{Nickerson, author = {Nickerson, Seth}, title = {Thermo-Mechanical Behavior of Honeycomb, Porous, Microcracked Ceramics}, doi = {10.25643/bauhaus-universitaet.3975}, url = {http://nbn-resolving.de/urn:nbn:de:gbv:wim2-20190911-39753}, school = {Bauhaus-Universit{\"a}t Weimar}, abstract = {The underlying goal of this work is to reduce the uncertainty related to thermally induced stress prediction. This is accomplished by considering use of non-linear material behavior, notably path dependent thermal hysteresis behavior in the elastic properties. Primary novel factors of this work center on two aspects. 1. Broad material characterization and mechanistic material understanding, giving insight into why this class of material behaves in characteristic manners. 2. Development and implementation of a thermal hysteresis material model and its use to determine impact on overall macroscopic stress predictions. Results highlight microcracking evolution and behavior as the dominant mechanism for material property complexity in this class of materials. Additionally, it was found that for the cases studied, thermal hysteresis behavior impacts relevant peak stress predictions of a heavy-duty diesel particulate filter undergoing a drop-to-idle regeneration by less than ~15\% for all conditions tested. It is also found that path independent heating curves may be utilized for a linear solution assumption to simplify analysis. This work brings forth a newly conceived concept of a 3 state, 4 path, thermally induced microcrack evolution process; demonstrates experimental behavior that is consistent with the proposed mechanisms, develops a mathematical framework that describes the process and quantifies the impact in a real world application space.}, subject = {Keramik}, language = {en} } @phdthesis{Schemmann, author = {Schemmann, Christoph}, title = {Optimierung von radialen Verdichterlaufr{\"a}dern unter Ber{\"u}cksichtigung empirischer und analytischer Vorinformationen mittels eines mehrstufigen Sampling Verfahrens}, doi = {10.25643/bauhaus-universitaet.3974}, url = {http://nbn-resolving.de/urn:nbn:de:gbv:wim2-20190910-39748}, school = {Bauhaus-Universit{\"a}t Weimar}, pages = {233}, abstract = {Turbomachinery plays an important role in many cases of energy generation or conversion. Therefore, turbomachinery is a promising approaching point for optimization in order to increase the efficiency of energy use. In recent years, the use of automated optimization strategies in combination with numerical simulation has become increasingly popular in many fields of engineering. The complex interactions between fluid and solid mechanics encountered in turbomachines on the one hand and the high computational expense needed to calculate the performance on the other hand, have, however, prevented a widespread use of these techniques in this field of engineering. The objective of this work was the development of a strategy for efficient metamodel based optimization of centrifugal compressor impellers. In this context, the main focus is the reduction of the required numerical expense. The central idea followed in this research was the incorporation of preliminary information acquired from low-fidelity computation methods and empirical correlations into the sampling process to identify promising regions of the parameter space. This information was then used to concentrate the numerically expensive high-fidelity computations of the fluid dynamic and structure mechanic performance of the impeller in these regions while still maintaining a good coverage of the whole parameter space. The development of the optimization strategy can be divided into three main tasks. Firstly, the available preliminary information had to be researched and rated. This research identified loss models based on one dimensional flow physics and empirical correlations as the best suited method to predict the aerodynamic performance. The loss models were calibrated using available performance data to obtain a high prediction quality. As no sufficiently exact models for the prediction of the mechanical loading of the impellercould be identified, a metamodel based on finite element computations was chosen for this estimation. The second task was the development of a sampling method which concentrates samples in regions of the parameter space where high quality designs are predicted by the preliminary information while maintaining a good overall coverage. As available methods like rejection sampling or Markov-chain Monte-Carlo methods did not meet the requirements in terms of sample distribution and input correlation, a new multi-fidelity sampling method called "Filtered Sampling"has been developed. The last task was the development of an automated computational workflow. This workflow encompasses geometry parametrization, geometry generation, grid generation and computation of the aerodynamic performance and the structure mechanic loading. Special emphasis was put into the development of a geometry parametrization strategy based on fluid mechanic considerations to prevent the generation of physically inexpedient designs. Finally, the optimization strategy, which utilizes the previously developed tools, was successfully employed to carry out three optimization tasks. The efficiency of the method was proven by the first and second testcase where an existing compressor design was optimized by the presented method. The results were comparable to optimizations which did not take preliminary information into account, while the required computational expense cloud be halved. In the third testcase, the method was applied to generate a new impeller design. In contrast to the previous examples, this optimization featuredlargervariationsoftheimpellerdesigns. Therefore, theapplicability of the method to parameter spaces with significantly varying designs could be proven, too.}, subject = {Simulation}, language = {en} } @phdthesis{Lee, author = {Lee, Sunju}, title = {Die kinder- und jugendfreundliche Stadtentwicklung in Korea}, doi = {10.25643/bauhaus-universitaet.3971}, url = {http://nbn-resolving.de/urn:nbn:de:gbv:wim2-20190902-39718}, school = {Bauhaus-Universit{\"a}t Weimar}, pages = {378}, abstract = {Die vorliegende Arbeit hat die Absicht, den Bedarf der Umsetzung der Planungsidee ‚kinder- und jugendfreundliche Stadtentwicklung' in Korea zu erforschen und Vorschl{\"a}ge f{\"u}r die Umsetzung zu machen. Dar{\"u}ber hinaus will sie herausfinden, warum man sich bez{\"u}glich der Durchf{\"u}hrung der kinder- und jugendfreundlichen Stadtentwicklung zun{\"a}chst auf die Schulen und deren Umgebungen konzentrieren soll. Deshalb widmet sich die Dissertation zuerst der Literaturrecherche, sowohl was den Begriff der kinder- und jugendfreundlichen Stadtentwicklung angeht als auch der Literatur bez{\"u}glich des Beitrags der Schulen zur Realisierung der kinder- und jugendfreundlichen Stadtentwicklung. Danach wird untersucht, ob das deutsche Instrument ‚Spielleitplanung' sich als Leitfaden f{\"u}r die gesamte Konzeption der koreanischen kinder- und jugendfreundlichen Stadtentwicklung eignet. Dar{\"u}ber hinaus werden Interviews mit koreanischen Experten aus Stadtplanung und Architektur, P{\"a}dagogik und {\"o}ffentlicher Verwaltung als Forschungsmethode verwendet, um in Bezug auf die kinder- jungendfreundliche Stadtentwicklung den koreanischen Zustand zu analysieren. Zuletzt werden anhand der Untersuchungsergebnisse Handlungs-empfehlungen f{\"u}r die Durchf{\"u}hrung der koreanischen kinder- und jugend-freundlichen Stadtentwicklung formuliert. Anhand dieser Forschung kann konstatiert werden, dass die kinder- und jugendfreundliche Stadtentwicklung eine wichtige Planungsidee ist, weil dadurch Stadtplanerinnen und Stadtplaner sowohl zum k{\"o}rperlichen und geistigen gesunden Aufwachsen von Kindern und Jugendlichen als auch zur Entwicklung ihrer sozialen Kompetenzen erheblich beitragen k{\"o}nnen. Vor allem soll man die koreanische kinder- und jugendfreundliche Stadtentwicklung zun{\"a}chst auf den Schulen und den schulischen Umgebungen umsetzen. Denn dadurch lassen sich vielseitige eventuelle Hindernisse bei der Durchf{\"u}hrung der kinder- und jugendfreundlichen Stadtentwicklung vermeiden. Ein weiterer Grund ist, dass die Schulen in Korea nicht nur in der Gesellschaft eine zentrale Rolle spielen, sondern auch im Rahmen der Stadtplanung. Auff{\"a}llig ist, dass die kinder- und jugendfreundliche Stadtentwicklung sowohl auf die r{\"a}umlichen Gestaltungen als auch auf die Beteiligung von Kindern und Jugendlichen in der st{\"a}dtischen Planung fokussiert ist. Allerdings werden bei der Stadtentwicklung die Kinder und Jugendliche in Korea noch nicht als wichtige Akteure angesehen. Darum soll man die Spielleitplanung in Korea einbeziehen, weil sie als Leitbild bei einer Konzeption der koreanischen kinder- und jugendlichen Stadtentwicklung fungieren kann. Jedoch m{\"u}ssen dabei die kulturellen Unterschiede zwischen Deutschland und Korea ber{\"u}cksichtigt werden. Weiterhin wurde durch die Interviews festgestellt, dass das Interesse und der Wille von Experten aus der Stadtplanung an Kinder- und Jugendfreundlichkeit die wichtigsten Voraussetzungen sind, um die kinder- und jugendfreundliche Stadtentwicklung in Korea zu verankern und zu verbreiten.}, subject = {Stadtentwicklung}, language = {de} } @phdthesis{Tan, author = {Tan, Fengjie}, title = {Shape Optimization Design of Arch Type Dams under Uncertainties}, doi = {10.25643/bauhaus-universitaet.3960}, url = {http://nbn-resolving.de/urn:nbn:de:gbv:wim2-20190819-39608}, school = {Bauhaus-Universit{\"a}t Weimar}, abstract = {Due to an increased need for hydro-electricity, water storage, and flood protection, it is assumed that a series of new dams will be built throughout the world. Comparing existing design methodologies for arch-type dams, model-based shape optimization can effectively reduce construction costs and leverage the properties of construction materials. To apply the means of shape optimization, suitable variables need to be chosen to formulate the objective function, which is the volume of the arch dam here. In order to increase the consistency with practical conditions, a great number of geometrical and behavioral constraints are included in the mathematical model. An optimization method, namely Genetic Algorithm is adopted which allows a global search. Traditional optimization techniques are realized based on a deterministic approach, which means that the material properties and loading conditions are assumed to be fixed values. As a result, the real-world structures that are optimized by these approaches suffer from uncertainties that one needs to be aware of. Hence, in any optimization process for arch dams, it is nec- essary to find a methodology that is capable of considering the influences of uncertainties and generating a solution which is robust enough against the uncertainties. The focus of this thesis is the formulation and the numerical method for the optimization of the arch dam under the uncertainties. The two main models, the probabilistic model, and non-probabilistic models are intro- duced and discussed. Classic procedures of probabilistic approaches un- der uncertainties, such as RDO (robust design optimization) and RBDO (reliability-based design optimization), are in general computationally ex- pensive and rely on estimates of the system's response variance and fail- ure probabilities. Instead, the robust optimization (RO) method which is based on the non-probabilistic model, will not follow a full probabilistic approach but works with pre-defined confidence levels. This leads to a bi-level optimization program where the volume of the dam is optimized under the worst combination of the uncertain parameters. By this, robust and reliable designs are obtained and the result is independent of any as- sumptions on stochastic properties of the random variables in the model. The optimization of an arch-type dam is realized here by a robust optimiza- tion method under load uncertainty, where hydraulic and thermal loads are considered. The load uncertainty is modeled as an ellipsoidal expression. Comparing with any traditional deterministic optimization (DO) method, which only concerns the minimum objective value and offers a solution candidate close to limit-states, the RO method provides a robust solution against uncertainties. All the above mentioned methods are applied to the optimization of the arch dam to compare with the optimal design with DO methods. The re- sults are compared and analyzed to discuss the advantages and drawbacks of each method. In order to reduce the computational cost, a ranking strategy and an ap- proximation model are further involved to do a preliminary screening. By means of these, the robust design can generate an improved arch dam structure which ensures both safety and serviceability during its lifetime.}, subject = {Wasserbau}, language = {en} } @phdthesis{Alalade, author = {Alalade, Muyiwa}, title = {An Enhanced Full Waveform Inversion Method for the Structural Analysis of Dams}, doi = {10.25643/bauhaus-universitaet.3956}, url = {http://nbn-resolving.de/urn:nbn:de:gbv:wim2-20190813-39566}, school = {Bauhaus-Universit{\"a}t Weimar}, abstract = {Since the Industrial Revolution in the 1700s, the high emission of gaseous wastes into the atmosphere from the usage of fossil fuels has caused a general increase in temperatures globally. To combat the environmental imbalance, there is an increase in the demand for renewable energy sources. Dams play a major role in the generation of "green" energy. However, these structures require frequent and strict monitoring to ensure safe and efficient operation. To tackle the challenges faced in the application of convention dam monitoring techniques, this work proposes the inverse analysis of numerical models to identify damaged regions in the dam. Using a dynamic coupled hydro-mechanical Extended Finite Element Method (XFEM) model and a global optimization strategy, damage (crack) in the dam is identified. By employing seismic waves to probe the dam structure, a more detailed information on the distribution of heterogeneous materials and damaged regions are obtained by the application of the Full Waveform Inversion (FWI) method. The FWI is based on a local optimization strategy and thus it is highly dependent on the starting model. A variety of data acquisition setups are investigated, and an optimal setup is proposed. The effect of different starting models and noise in the measured data on the damage identification is considered. Combining the non-dependence of a starting model of the global optimization strategy based dynamic coupled hydro-mechanical XFEM method and the detailed output of the local optimization strategy based FWI method, an enhanced Full Waveform Inversion is proposed for the structural analysis of dams.}, subject = {Talsperre}, language = {en} } @phdthesis{Jahreis, author = {Jahreis, Markus}, title = {Zur Entwicklung von Polymerverguss-Kopplungselementen f{\"u}r den Holzbau}, doi = {10.25643/bauhaus-universitaet.3945}, url = {http://nbn-resolving.de/urn:nbn:de:gbv:wim2-20190731-39458}, school = {Bauhaus-Universit{\"a}t Weimar}, pages = {229}, abstract = {Den Schwerpunkt der vorliegenden Arbeit bilden die konstruktive Entwicklung und die wissenschaftliche Untersuchung des Tragverhaltens von Kopplungselementen f{\"u}r den Ingenieur¬holzbau. Die neu entwickelten Verbindungen bestehen bevorzugt aus Stahlteilen mit Gewindeanschluss und werden mit einem Polymerverguss im Holz verankert. Die Kopplungselemente gestatten die einfache montagegerechte Verbindung von Holzbauteilen untereinander oder zu anderen Bauweisen. Sie nehmen die Zug- oder Drucklast axial auf und gew{\"a}hrleisten eine leistungsf{\"a}hige und schlupf¬freie Verbindung zum Holz. F{\"u}r den Verguss wird ein mineralisch gef{\"u}lltes Epoxidharz mit sehr guten Klebeeigenschaften gegen{\"u}ber Holz und den meisten {\"u}blichen Baustoffen verwendet. Im Holz werden f{\"u}r die Verankerung der Kopplungselemente Bohrungen vorgesehen, die sich sowohl aus technologischen Gr{\"u}nden als auch f{\"u}r eine gleichm{\"a}ßige Spannungsverteilung vorteilhaft erweisen. Der Durchmesser der Bohrung ist gegen{\"u}ber dem Verbindungselement deutlich gr{\"o}ßer, wodurch die Verbindungsfl{\"a}che zum Holz bei konstanter L{\"a}nge ansteigt. Die Vergr{\"o}ßerung der Fugen zwischen dem Verbindungselement und der Holzwandung von 7 mm auf 17 mm f{\"u}hrt bei konstanter Einbindetiefe und gleichem Durchmesser des Verbin¬dungsmittels zu einer Laststeigerung von {\"u}ber 20 \%. Die gr{\"o}ßere Vergussfuge gew{\"a}hrleistet dar{\"u}ber hinaus eine Vergleichm{\"a}ßigung der Spannungen innerhalb der Verbindung, den Ein¬satz von frei geformten Verbindungselementen und eine Vereinfachung der Herstellung. Die Kopplungselemente sind f{\"u}r den Einsatz in Zug- oder Druckst{\"o}ßen ebenso geeignet wie f{\"u}r biegesteife Anschl{\"u}sse axial verbundener Biegetr{\"a}ger oder Rahmenecken. Sie k{\"o}nnen werkseitig im Holzbauteil vorgesehen oder als direkte Verbindung auf der Baustelle vergossen werden. F{\"u}r die Baupraxis wird durch den Einsatz des schwindarmen Verguss-materials mit hoher Klebewirkung eine Bandbreite an Anwendungen vom Toleranzausgleich {\"u}ber Schubbewehrung bis zum Druck-, Zug- oder Biegeanschluss geboten.}, subject = {Holzbau}, language = {de} } @phdthesis{Everts, author = {Everts, Lotte}, title = {"Hey! I'm an Angel!" Zum Verh{\"a}ltnis von Medium, Subjekt und Wirklichkeit in Eija-Liisa Ahtilas Videoinstallationen}, doi = {10.25643/bauhaus-universitaet.3947}, url = {http://nbn-resolving.de/urn:nbn:de:gbv:wim2-20190730-39471}, school = {Bauhaus-Universit{\"a}t Weimar}, pages = {229}, abstract = {Die Dissertation „Hey! I'm an Angel! Zum Verh{\"a}ltnis von Medium, Subjekt und Wirklichkeit in Eija-Liisa Ahtilas Videoinstallationen" untersucht in der Hauptsache vier zentrale Videoinstallationen Ahtilas aus den Jahren 1995 bis 2014. Grundlegend ist die These, dass Ahtilas Arbeiten nicht, wie bisher angenommen, in den Kontext einer medien-, erkenntnis- und subjektkritischen Videokunst einzuordnen sind. Stattdessen werden sie als mediale Vehikel intersubjektiv gepr{\"a}gter Wirklichkeitserfahrungen f{\"u}r das Subjekt bereitgestellt: Entgegen dem aktuellen Forschungsstand arbeitet sich Ahtila nicht an der Kritik des Mediums Film/Video ab, das einen wirklichkeitsverf{\"a}lschenden oder -ersetzenden Einfluss auf das manipulierte Subjekt nimmt. Vielmehr nutzt die K{\"u}nstlerin das Potenzial des Mediums Film/Video aus, um einem relativ stabilen Subjekt die Wirklichkeitserfahrungen Anderer zu {\"o}ffnen und auf diese Weise seinen Erfahrungshorizont zu erweitern. Der systematische Schwerpunkt der Arbeit liegt erstens darauf, ein sich durch Ahtilas bisheriges Schaffen ziehendes ‚Ziel' der Integration der Betrachterin in eine intersubjektive Erfahrungssph{\"a}re nachvollziehbar zu machen. Hierf{\"u}r wird insbesondere eine Perspektive auf die fr{\"u}hen Arbeiten entwickelt, in der die Br{\"u}che in Ahtila Arbeiten integrative statt distanzierende Wirkung haben. Zweitens wird in eingehenden Analysen der Wandel verst{\"a}ndlich, der sich zwischen Ahtilas fr{\"u}her Schaffensphase (1995 - 2002) und der aktuellen Schaffensphase (seit 2010) hinsichtlich der Art und Weise vollzieht, wie diese Integration gelingt. Es zeigt sich, dass der Einstieg in die intersubjektiv gepr{\"a}gten Erfahrungssph{\"a}ren in der fr{\"u}hen Phase {\"a}sthetisch konstituiert ist. Mit der aktuellen Schaffensphase werden hingegen allt{\"a}gliche Formen der Empathie und Mimesis zentral, sowie deren leibliche Konsequenzen f{\"u}r die Betrachterin. Drittens wird eine zunehmende pragmatische Tendenz darin deutlich, die Integration der Betrachterin in die Erfahrungen Anderer zu erm{\"o}glichen. Dies wird vor dem Hintergrund eines allgemeinen pragmatischen Zuges aktueller zeitgeistiger Bewegungen erl{\"a}utert. Viertens wird gezeigt, dass Ahtilas Arbeiten auf der Annahme einer Kontinuit{\"a}t in gewisser Hinsicht von der außerfilmischen Wirklichkeit in die filmische Fiktion hinein basieren, sowie auf dem Verst{\"a}ndnis filmischer Fiktionen als virtuelle Weltfassungen. Ahtila fragt auf der Grundlage dieses Verst{\"a}ndnisses filmischer Fiktion nicht nach der Wahrheit dieser Fiktion als These {\"u}ber die Wirklichkeit, wie es dem Forschungskanon {\"u}ber die K{\"u}nstlerin zu entnehmen ist. Sondern nach der Wirksamkeit der filmischen Fiktion f{\"u}r die Wirklichkeit.}, subject = {Videokunst}, language = {de} } @phdthesis{Voelske, author = {V{\"o}lske, Michael}, title = {Retrieval Enhancements for Task-Based Web Search}, doi = {10.25643/bauhaus-universitaet.3942}, url = {http://nbn-resolving.de/urn:nbn:de:gbv:wim2-20190709-39422}, school = {Bauhaus-Universit{\"a}t Weimar}, abstract = {The task-based view of web search implies that retrieval should take the user perspective into account. Going beyond merely retrieving the most relevant result set for the current query, the retrieval system should aim to surface results that are actually useful to the task that motivated the query. This dissertation explores how retrieval systems can better understand and support their users' tasks from three main angles: First, we study and quantify search engine user behavior during complex writing tasks, and how task success and behavior are associated in such settings. Second, we investigate search engine queries formulated as questions, and explore patterns in a large query log that may help search engines to better support this increasingly prevalent interaction pattern. Third, we propose a novel approach to reranking the search result lists produced by web search engines, taking into account retrieval axioms that formally specify properties of a good ranking.}, subject = {Information Retrieval}, language = {en} } @phdthesis{PuentesRivera, author = {Puentes-Rivera, Yomayra}, title = {WHISPERS OF MEMORY, MURMURS OF HISTORY ACOUSTIC MONU-MEMORIALS IN PUBLIC SPACES. Exploratory research of strategies used to create acoustic experiences of commemoration, remembrance, mourning and memory}, doi = {10.25643/bauhaus-universitaet.3932}, url = {http://nbn-resolving.de/urn:nbn:de:gbv:wim2-20190603-39323}, school = {Bauhaus-Universit{\"a}t Weimar}, pages = {265}, abstract = {This research seeks to make an exploratory study of the strategies used by the creators of monuments, memorials, and commemorative places located in the public spaces that use sound as one of the primary raw material in their design. The term acoustic monu-memorials was coined in this research to encircle these structures and places. In order to achieve the goal of this research, it was necessary to compile a number of samples, primarily after the digital recording era of captured sound around 1971 to the present. The compilation was relevant because such a compendium was not found in the literature, and to the author's knowledge, a comprehensive investigation of the strategies used in planning acoustic monu-memorials in the urban spaces does not exist. The method used to create such compendium was to send a question to people with different background identities, such as visual and sound artists, musicians, art curators, and heritage scholars among others. This question produced a selection of 51 examples of acoustic monu-memorials located in public spaces. Subsequently, the examples were classified into four major categories according to their form and nature. Additionally, two examples from the main categories were chosen as case studies: The Sinti and Roma Memorial in Berlin, Germany and the Niche monument in Cali, Colombia. These study cases were presented, described, and analysed in detail as they represent the type of what could be defined as an acoustic monu-memorial in general. Lynch's (1960) five elements that help individuals build the image of the city were transferred and used as a tool to help to build this image into acoustic terms. A thorough analysis of the acquired data yielded found the strategies used by the designers to shape, modify, transform, and structure public space. These strategies are entitled Sound Spaces. Moreover, a list entitled Urban Acoustic Commemoration Code was compiled. This list of suggestions addresses urban planners, architects, artists, designers, and general public interested in the aspects involved when creating acoustic commemoration phenomena in public spaces.}, subject = {Stadtentwicklung}, language = {en} } @phdthesis{Steiner, author = {Steiner, Marion}, title = {Die chilenische Steckdose. Kleine Weltgeschichte der deutschen Elektrifizierung von Valpara{\´i}so und Santiago, 1880-1920}, doi = {10.25643/bauhaus-universitaet.3925}, url = {http://nbn-resolving.de/urn:nbn:de:gbv:wim2-20190517-39257}, school = {Bauhaus-Universit{\"a}t Weimar}, pages = {507, 155}, abstract = {Am Beispiel der Elektrifizierung zweier Großst{\"a}dte an der Westk{\"u}ste S{\"u}damerikas zeigt die Arbeit den globalen Einfluss deutscher Industrie- und Finanzakteure auf technische, st{\"a}dtebauliche und gesellschaftlich-kulturelle Entwicklungen zur Bl{\"u}tezeit des europ{\"a}ischen Imperialismus auf. Damit werden die Regionalgeschichten der chilenischen Hauptstadtregion und der Elektropolis Berlin zu einer Globalgeschichte miteinander verkn{\"u}pft. Ein Hauptaugenmerk der Analyse liegt dabei auf den weltweiten Akteursnetzwerken und Machtverh{\"a}ltnissen sowie dem kulturellen Erbe und seiner gegenw{\"a}rtigen Interpretation.}, subject = {Weltgeschichte}, language = {de} } @phdthesis{AlYasiri2017, author = {Al-Yasiri, Zainab Riyadh Shaker}, title = {Function Theoretic Methods for the Analytical and Numerical Solution of Some Non-linear Boundary Value Problems with Singularities}, doi = {10.25643/bauhaus-universitaet.3898}, url = {http://nbn-resolving.de/urn:nbn:de:gbv:wim2-20190506-38987}, school = {Bauhaus-Universit{\"a}t Weimar}, pages = {164}, year = {2017}, abstract = {The p-Laplace equation is a nonlinear generalization of the well-known Laplace equation. It is often used as a model problem for special types of nonlinearities, and therefore it can be seen as a bridge between very general nonlinear equations and the linear Laplace equation, too. It appears in many problems for instance in the theory of non-Newtonian fluids and fluid dynamics or in rockfill dam problems, as well as in special problems of image restoration and image processing. The aim of this thesis is to solve the p-Laplace equation for 1 < p < 2, as well as for 2 < p < 3 and to find strong solutions in the framework of Clifford analysis. The idea is to apply a hypercomplex integral operator and special function theoretic methods to transform the p-Laplace equation into a p-Dirac equation. We consider boundary value problems for the p-Laplace equation and transfer them to boundary value problems for a p-Dirac equation. These equations will be solved iteratively by applying Banach's fixed-point principle. Applying operator-theoretical methods for the p-Dirac equation, the existence and uniqueness of solutions in certain Sobolev spaces will be proved. In addition, using a finite difference approach on a uniform lattice in the plane, the fundamental solution of the Cauchy-Riemann operator and its adjoint based on the fundamental solution of the Laplacian will be calculated. Besides, we define gener- alized discrete Teodorescu transform operators, which are right-inverse to the discrete Cauchy-Riemann operator and its adjoint in the plane. Furthermore, a new formula for generalized discrete boundary operators (analogues of the Cauchy integral operator) will be considered. Based on these operators a new version of discrete Borel-Pompeiu formula is formulated and proved. This is the basis for an operator calculus that will be applied to the numerical solution of the p-Dirac equation. Finally, numerical results will be presented showing advantages and problems of this approach.}, subject = {Finite-Differenzen-Methode}, language = {en} } @phdthesis{Nogueira2018, author = {Nogueira, Priscilla}, title = {Brazilian battlers' housing. Histories of self-production - histories of social rise}, doi = {10.25643/bauhaus-universitaet.3895}, url = {http://nbn-resolving.de/urn:nbn:de:gbv:wim2-20190506-38953}, school = {Bauhaus-Universit{\"a}t Weimar}, pages = {357}, year = {2018}, abstract = {Brazilian battlers' housing discusses the self-production of dwellings in the circumstances of the socioeconomic rise of the so-called Brazilian new middle class, occurred on the first decade of the years 2000. Battlers are a precarious working class of about 100 million people, who have used their recently increased purchase power to informally solve their private housing demands, planning, building and renovating their homes themselves, with limited technical knowledge and almost no access to formal technicians as for example architects. The result is a mode of housing production, which spreads over the territory in micro-local self-initiatives and informal social practices of construction and management. With the support of a controversial manpower, this practice presents all sorts of technical complications, but at the same time expedient ways of affordability and creative spatial solutions for ordinary constructive problems. Such initiatives have consolidated Brazilian informal settlements and peripheral subdivisions, attending a demand poorly responded by the government. This research recognises the benefits of the self-production, but questions the conditions under which it happens and asks if it really collaborates for a true social rise of those who are engaged in it. With an empirical and qualitative approach and taking dwelling construction processes leaded by battlers as main information sources, the academic work responds if and how the socioeconomic rise of the Brazilian battlers has exactly affected the self-production of dwellings. For that, battlers' self-production of dwellings is analysed and discussed in five main aspects: 1) acquisition of land and real state, 2) building overtime, 3) space and creative power, 4) technical complications and building materials and 5) manpower and know-how.}, subject = {Sozialwohnung}, language = {en} } @phdthesis{Beck, author = {Beck, Stephan}, title = {Immersive Telepresence Systems and Technologies}, doi = {10.25643/bauhaus-universitaet.3856}, url = {http://nbn-resolving.de/urn:nbn:de:gbv:wim2-20190218-38569}, school = {Bauhaus-Universit{\"a}t Weimar}, pages = {149}, abstract = {Modern immersive telepresence systems enable people at different locations to meet in virtual environments using realistic three-dimensional representations of their bodies. For the realization of such a three-dimensional version of a video conferencing system, each user is continuously recorded in 3D. These 3D recordings are exchanged over the network between remote sites. At each site, the remote recordings of the users, referred to as 3D video avatars, are seamlessly integrated into a shared virtual scenery and displayed in stereoscopic 3D for each user from his or her perspective. This thesis reports on algorithmic and technical contributions to modern immersive telepresence systems and presents the design, implementation and evaluation of the first immersive group-to-group telepresence system in which each user is represented as realistic life-size 3D video avatar. The system enabled two remote user groups to meet and collaborate in a consistent shared virtual environment. The system relied on novel methods for the precise calibration and registration of color- and depth- sensors (RGBD) into the coordinate system of the application as well as an advanced distributed processing pipeline that reconstructs realistic 3D video avatars in real-time. During the course of this thesis, the calibration of 3D capturing systems was greatly improved. While the first development focused on precisely calibrating individual RGBD-sensors, the second stage presents a new method for calibrating and registering multiple color and depth sensors at a very high precision throughout a large 3D capturing volume. This method was further refined by a novel automatic optimization process that significantly speeds up the manual operation and yields similarly high accuracy. A core benefit of the new calibration method is its high runtime efficiency by directly mapping from raw depth sensor measurements into an application coordinate system and to the coordinates of its associated color sensor. As a result, the calibration method is an efficient solution in terms of precision and applicability in virtual reality and immersive telepresence applications. In addition to the core contributions, the results of two case studies which address 3D reconstruction and data streaming lead to the final conclusion of this thesis and to directions of future work in the rapidly advancing field of immersive telepresence research.}, subject = {Virtuelle Realit{\"a}t}, language = {en} } @phdthesis{Weitze, author = {Weitze, Laura Katharina}, title = {Erweiterte Prozessbewertung von Biogasanlagen unter Ber{\"u}cksichtigung organoleptischer Parameter und Erfahrungswissen}, doi = {10.25643/bauhaus-universitaet.3849}, url = {http://nbn-resolving.de/urn:nbn:de:gbv:wim2-20190129-38499}, school = {Bauhaus-Universit{\"a}t Weimar}, pages = {308}, abstract = {Landwirtschaftliche Biogasanlagen leisten mit ca. 9.300 Anlagen und einem Anteil von 5,3\% an der Stromerzeugung, einen Beitrag zur Erzeugung Erneuer-barer Energien in Deutschland. Die Optimierung dieser Anlagen f{\"o}rdert die nachhaltige Bereitstellung von Strom, W{\"a}rme und BioErdgas. Das Ergebnis dieser Forschungsarbeit ist die Entwicklung eines mehrmethodi-schen Bewertungsansatzes zur Beschreibung der Qualit{\"a}t der Eingangs-substrate als Teil einer ganzheitlichen Prozessoptimierung. Dies gelingt durch die kombinierte Nutzung klassischer Analyses{\"a}tze, der Nutzung organolepti-scher Parameter - der humansensorischen Sinnenpr{\"u}fung - und der Integration von prozess- und substratspezifischem Erfahrungswissen. Anhand von halbtechnischen Versuchen werden Korrelationen und Kausalit{\"a}ten zwi-schen chemisch-physikalischen, biologischen, organoleptischen und erfahrungsbezogenen Parametern erforscht. Die Entwicklung einer Fallbasis mit Hilfe des Fallbasierten Schließens, einer Form K{\"u}nstlicher Intelligenz, zeigt das Entwicklungs- und Integrationspotenzial der Automatisierung auf, insbesondere auch im Hinblick auf neue Ans{\"a}tze z.B. Industrie 4.0. Erste L{\"o}sungen zur Bew{\"a}ltigung der identifizierten Herausforderungen der mehrmethodischen Prozessbewertung werden vorgestellt. Abschließend wird ein Ausblick auf den weiteren Forschungsbedarf gegeben und die {\"U}bertragbarkeit des mehrmethodischen Bewertungsansatzes auf andere Anwendungsfelder z.B. Bioabfallbehandlung, Kl{\"a}ranlagen angeregt.}, subject = {Biogasanlage}, language = {de} } @phdthesis{ZHANG2018, author = {ZHANG, CHAO}, title = {Crack Identification using Dynamic Extended Finite Element Method and Thermal Conductivity Engineering for Nanomaterials}, doi = {10.25643/bauhaus-universitaet.3847}, url = {http://nbn-resolving.de/urn:nbn:de:gbv:wim2-20190119-38478}, school = {Bauhaus-Universit{\"a}t Weimar}, year = {2018}, abstract = {Identification of flaws in structures is a critical element in the management of maintenance and quality assurance processes in engineering. Nondestructive testing (NDT) techniques based on a wide range of physical principles have been developed and are used in common practice for structural health monitoring. However, basic NDT techniques are usually limited in their ability to provide the accurate information on locations, dimensions and shapes of flaws. One alternative to extract additional information from the results of NDT is to append it with a computational model that provides detailed analysis of the physical process involved and enables the accurate identification of the flaw parameters. The aim here is to develop the strategies to uniquely identify cracks in two-dimensional 2D) structures under dynamic loadings. A local NDT technique combined eXtended Finite Element Method (XFEM) with dynamic loading in order to identify the cracks in the structures quickly and accurately is developed in this dissertation. The Newmark-b time integration method with Rayleigh damping is used for the time integration. We apply Nelder-Mead (NM)and Quasi-Newton (QN) methods for identifying the crack tip in plate. The inverse problem is solved iteratively, in which XFEM is used for solving the forward problem in each iteration. For a timeharmonic excitation with a single frequency and a short-duration signal measured along part of the external boundary, the crack is detected through the solution of an inverse time-dependent problem. Compared to the static load, we show that the dynamic loads are more effective for crack detection problems. Moreover, we tested different dynamic loads and find that NM method works more efficient under the harmonic load than the pounding load while the QN method achieves almost the same results for both load types. A global strategy, Multilevel Coordinate Search (MCS) with XFEM (XFEM-MCS) methodology under the dynamic electric load, to detect multiple cracks in 2D piezoelectric plates is proposed in this dissertation. The Newmark-b method is employed for the time integration and in each iteration the forward problem is solved by XFEM for various cracks. The objective functional is minimized by using a global search algorithm MCS. The test problems show that the XFEM-MCS algorithm under the dynamic electric load can be effectively employed for multiple cracks detection in piezoelectric materials, and it proves to be robust in identifying defects in piezoelectric structures. Fiber-reinforced composites (FRCs) are extensively applied in practical engineering since they have high stiffness and strength. Experiments reveal a so-called interphase zone, i.e. the space between the outside interface of the fiber and the inside interface of the matrix. The interphase strength between the fiber and the matrix strongly affects the mechanical properties as a result of the large ratio of interface/volume. For the purpose of understanding the mechanical properties of FRCs with functionally graded interphase (FGI), a closed-form expression of the interface strength between a fiber and a matrix is obtained in this dissertation using a continuum modeling approach according to the ver derWaals (vdW) forces. Based on the interatomic potential, we develop a new modified nonlinear cohesive law, which is applied to study the interface delamination of FRCs with FGI under different loadings. The analytical solutions show that the delamination behavior strongly depends on the interphase thickness, the fiber radius, the Young's moduli and Poisson's ratios of the fiber and the matrix. Thermal conductivity is the property of a material to conduct heat. With the development and deep research of 2D materials, especially graphene and molybdenum disulfide (MoS2), the thermal conductivity of 2D materials attracts wide attentions. The thermal conductivity of graphene nanoribbons (GNRs) is found to appear a tendency of decreasing under tensile strain by classical molecular dynamics (MD) simulations. Hence, the strain effects of graphene can play a key role in the continuous tunability and applicability of its thermal conductivity property at nanoscale, and the dissipation of thermal conductivity is an obstacle for the applications of thermal management. Up to now, the thermal conductivity of graphene under shear deformation has not been investigated yet. From a practical point of view, good thermal managements of GNRs have significantly potential applications of future GNR-based thermal nanodevices, which can greatly improve performances of the nanosized devices due to heat dissipations. Meanwhile, graphene is a thin membrane structure, it is also important to understand the wrinkling behavior under shear deformation. MoS2 exists in the stable semiconducting 1H phase (1H-MoS2) while the metallic 1T phase (1T-MoS2) is unstable at ambient conditions. As it's well known that much attention has been focused on studying the nonlinear optical properties of the 1H-MoS2. In a very recent research, the 1T-type monolayer crystals of TMDCs, MX2 (MoS2, WS2 ...) was reported having an intrinsic in-plane negative Poisson's ratio. Luckily, nearly at the same time, unprecedented long-term (>3months) air stability of the 1T-MoS2 can be achieved by using the donor lithium hydride (LiH). Therefore, it's very important to study the thermal conductivity of 1T-MoS2. The thermal conductivity of graphene under shear strain is systematically studied in this dissertation by MD simulations. The results show that, in contrast to the dramatic decrease of thermal conductivity of graphene under uniaxial tensile, the thermal conductivity of graphene is not sensitive to the shear strain, and the thermal conductivity decreases only 12-16\%. The wrinkle evolves when the shear strain is around 5\%-10\%, but the thermal conductivity barely changes. The thermal conductivities of single-layer 1H-MoS2(1H-SLMoS2) and single-layer 1T-MoS2 (1T-SLMoS2) with different sample sizes, temperatures and strain rates have been studied systematically in this dissertation. We find that the thermal conductivities of 1H-SLMoS2 and 1T-SLMoS2 in both the armchair and the zigzag directions increase with the increasing of the sample length, while the increase of the width of the sample has minor effect on the thermal conductions of these two structures. The thermal conductivity of 1HSLMoS2 is smaller than that of 1T-SLMoS2 under size effect. Furthermore, the temperature effect results show that the thermal conductivities of both 1H-SLMoS2 and 1T-SLMoS2 decrease with the increasing of the temperature. The thermal conductivities of 1HSLMoS2 and 1T-SLMoS2 are nearly the same (difference <6\%) in both of the chiral orientations under corresponding temperatures, especially in the armchair direction (difference <2.8\%). Moreover, we find that the strain effects on the thermal conductivity of 1HSLMoS2 and 1T-SLMoS2 are different. More specifically, the thermal conductivity decreases with the increasing tensile strain rate for 1T-SLMoS2, while fluctuates with the growth of the strain for 1HSLMoS2. Finally, we find that the thermal conductivity of same sized 1H-SLMoS2 is similar with that of the strained 1H-SLMoS2 structure.}, subject = {crack}, language = {en} } @phdthesis{Kessler2018, author = {Keßler, Andrea}, title = {Matrix-free voxel-based finite element method for materials with heterogeneous microstructures}, doi = {10.25643/bauhaus-universitaet.3844}, url = {http://nbn-resolving.de/urn:nbn:de:gbv:wim2-20190116-38448}, school = {Bauhaus-Universit{\"a}t Weimar}, pages = {113}, year = {2018}, abstract = {Modern image detection techniques such as micro computer tomography (μCT), magnetic resonance imaging (MRI) and scanning electron microscopy (SEM) provide us with high resolution images of the microstructure of materials in a non-invasive and convenient way. They form the basis for the geometrical models of high-resolution analysis, so called image-based analysis. However especially in 3D, discretizations of these models reach easily the size of 100 Mill. degrees of freedoms and require extensive hardware resources in terms of main memory and computing power to solve the numerical model. Consequently, the focus of this work is to combine and adapt numerical solution methods to reduce the memory demand first and then the computation time and therewith enable an execution of the image-based analysis on modern computer desktops. Hence, the numerical model is a straightforward grid discretization of the voxel-based (pixels with a third dimension) geometry which omits the boundary detection algorithms and allows reduced storage of the finite element data structure and a matrix-free solution algorithm. This in turn reduce the effort of almost all applied grid-based solution techniques and results in memory efficient and numerically stable algorithms for the microstructural models. Two variants of the matrix-free algorithm are presented. The efficient iterative solution method of conjugate gradients is used with matrix-free applicable preconditioners such as the Jacobi and the especially suited multigrid method. The jagged material boundaries of the voxel-based mesh are smoothed through embedded boundary elements which contain different material information at the integration point and are integrated sub-cell wise though without additional boundary detection. The efficiency of the matrix-free methods can be retained.}, subject = {Dissertation}, language = {en} } @phdthesis{MizrakBilen, author = {Mizrak Bilen, Burcin}, title = {A Power-Centered Approach to the Capitalization of Climate Change in Property Sector and Strategic Limitation}, doi = {10.25643/BAUHAUS-UNIVERSITAET.3840}, url = {http://nbn-resolving.de/urn:nbn:de:gbv:wim2-20190107-38406}, school = {Bauhaus-Universit{\"a}t Weimar}, pages = {256}, abstract = {The capitalization of 'certified' sustainable building sector will be investigated over the power theory of value approach of Jonathan Nitzan and Shimshon Bichler. The study will be initiated by questioning why the environment problems are one of the first items on the agenda and by sharing the ideas of scholars who approaches the subject skeptically, because the predominant literature underlying the necessity and prominence of the topic is already well-known and adapted by the majority. Over the theory developed by Nitzan and Bichler, the concepts of capitalization, strategic sabotage, power, legitimacy, and obedience will be discussed. The hypothesis of "the absentee owners of the construction sector, holding the whip hand and capitalizing the ecology, control the growth and the creativity of green building production and make it carbon-dependent, in order to increase their profit margin" will be questioned. To strengthen the arguments in the hypothesis, the factors, the institutional arrangements, value measurement methods, which affect directly the net present value, will be investigated both in corporation and in building scale in detail, because net present value/ capitalization is asserted as the most important criteria by Nitzan and Bichler to make the investment decisions in the capitalist economic system. To trace the implications of power and the strategic sabotage that power caused, as the empirical dimension of this dissertation, an interface exploring the correlational ties between the climate responsive architecture and the ever changing political, economical, and social contexts and building economics praxis by decades will be developed and the expert interviews will be conducted with the design teams and the appraisers.}, subject = {Klima{\"a}nderung}, language = {en} } @phdthesis{Strassmann, author = {Straßmann, Sarah}, title = {Expanded Pictures: Das Handlungsgef{\"u}ge des fotografischen Bildes im Kontext von Internet und Social Media}, doi = {10.25643/bauhaus-universitaet.3838}, url = {http://nbn-resolving.de/urn:nbn:de:gbv:wim2-20190102-38388}, school = {Bauhaus-Universit{\"a}t Weimar}, pages = {164}, abstract = {In der vorliegenden Arbeit wird die Bedeutung und Funktion des fotografischen Bildes und im Besonderen der Handyfotografie im Kontext von Internet und sozialen Onlinenetzwerken beschrieben, untersucht und diskutiert. Im Spannungsfeld zwischen sozialwissenschaftlichen Theorien, foto- und medientheoretischem Diskurs sowie {\"a}sthetisch k{\"u}nstlerischen Perspektiven wird ausgelotet, welche konkreten visuellen und sozialen Formen die gegenw{\"a}rtige mobile digitale Bildpraxis angenommen hat, wie sich ihre Gebrauchsweise innerhalb des globalen gesellschaftlichen Alltags darstellt, und in welcher Weise ihr spezielles Zusammenspiel aus „shooting", „uploading", „sharing" zu neuen menschlichen Handlungsmustern und zur Schaffung neuer kultureller Realit{\"a}ten beitr{\"a}gt.}, subject = {Digitale Fotografie}, language = {de} }