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 - 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 - 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 - 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 - 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 - 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 - 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 - 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 - 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 - 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 - 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 - 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 - 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 - 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 - 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 - 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 - 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 -