@phdthesis{Zhu, author = {Zhu, Pengtao}, title = {The Variability of the Void Ratio of Sand and its Effect on Settlement and Infinite Slope Stability}, doi = {10.25643/bauhaus-universitaet.3741}, url = {http://nbn-resolving.de/urn:nbn:de:gbv:wim2-20180403-37411}, school = {Bauhaus-Universit{\"a}t Weimar}, pages = {164}, abstract = {The uncertainty of a soil property can significantly affect the physical behavior of soil, so as to influence geotechnical practice. The uncertainty can be expressed by its stochastic parameters, including the mean, the standard deviation, and the spatial correlation length. These stochastic parameters are regarded as constant value in most of the former studies. The main aim of this thesis is to prove whether they are depth-dependent, and to evaluate the effect of this depth-dependent character on both the settlement and the infinite slope stability during rainwater infiltration. A stochastic one-dimensional settlement simulation is carried out using random finite element method with the von Wolffersdorff hypoplastic model, so as to evaluate the effect of stress level on the stochastic parameters of void ratio related parameters of sand. It is found that these stochastic parameters are both stress-dependent and depth-dependent. The non-stationary random field, considering the depth-dependent character of these stochastic parameters, can be generated through the distortion of the stationary random field. The one-dimensional settlement analysis is carried out to evaluation the effect of the depth-dependent character of the stochastic parameters of void ratio on the strain. It is found that the depth-dependent character has low effect on the strain. The deterministic analysis of infinite slope stability during rainwater infiltration is simulated. The transient seepage is carried out using finite difference method, while the steady state seepage is simulated using the analytical solution. The saturated hydraulic conductivity (ks) is taken as the only variable. The results show that the depth-dependent ks has a significant influence on the stability of the slope when the negative flux is high. Without considering the depth-dependent character, can overestimate the factor of safety of the slope. A slope can fail if the depth-dependent character is considered, while it is stable if the depth-dependent character is neglected. The failure time of the slope with a greater depth-dependent ks is earlier during transient infiltration. Meanwhile, the stochastic infinite slope stability analysis during infiltration, is also carried out to highlight the effect of the depth-dependent character of the stochastic parameters of ks. The results show that: the probability of failure is significantly increased if the depth-dependent character of mean is considered, while, it is moderately reduced if the depth-dependent character of the standard deviation is accounted. If the depth-dependent character of both the mean and standard deviation of ks is considered, the depth-dependent mean value plays a dominant influence on the results. Furthermore, the depth-dependent character of the spatial correlation length can slightly reduce the probability of failure.}, subject = {Bodenunruhe}, language = {en} } @article{Wolf, author = {Wolf, Christiane}, title = {Transportschein f{\"u}r eine Bronzefigur - Empfangsstation Weimar. Ein Versuch zu "Eva geh{\"o}rt zu uns"}, doi = {10.25643/bauhaus-universitaet.4206}, url = {http://nbn-resolving.de/urn:nbn:de:gbv:wim2-20200727-42061}, pages = {6}, abstract = {Vortrag {\"u}ber die Restaurierung der Bronzeplastik zur feierlichen Wiederaufstellung der von Auguste Rodin gestalteten Plastik "Eva" auf ihren angestammten Platz im Foyer des Hauptgeb{\"a}udes der Bauhaus-Universit{\"a}t Weimar am 12. Dezember 2018}, subject = {Plasik}, language = {de} } @article{WernerHaaseRenneretal., author = {Werner, Franziska and Haase, Annegret and Renner, Nona and Rink, Dieter and Rottwinkel, Malena and Schmidt, Anika}, title = {The Local Governance of Arrival in Leipzig: Housing of Asylum-Seeking Persons as a Contested Field}, series = {Urban Planning}, journal = {Urban Planning}, number = {Volume 3, Issue 4}, editor = {Eckardt, Frank}, publisher = {Cogitatio Press}, doi = {10.17645/up.v3i4.1708}, url = {http://nbn-resolving.de/urn:nbn:de:gbv:wim2-20190122-38460}, pages = {116 -- 128}, abstract = {The article examines how the German city of Leipzig governs the housing of asylum seekers. Leipzig was a frontrunner in organizing the decentralized accommodation of asylum seekers when adopting its accommodation concept in 2012. This concept aimed at integrating asylum-seeking persons in the regular housing market at an early stage of arrival. However, since then, the city of Leipzig faces more and more challenges in implementing the concept. This is particularly due to the increasingly tight situation on the housing market while the number of people seeking protection increased and partly due to discriminating and xenophobic attitudes on the side of house owners and managers. Therefore, we argue that the so-called refugee crisis of 2015-2016 has to be seen in close interaction with a growing general housing shortage in Leipzig like in many other large European cities. Furthermore, we understand the municipal governing of housing as a contested field regarding its entanglement of diverse federal levels and policy scales, the diversity of stakeholders involved, and its dynamic change over the last years. We analyze this contested field set against the current context of arrival and dynamic urban growth on a local level. Based on empirical qualitative research that was conducted by us in 2016, Leipzig's local specifics will be investigated under the umbrella of our conceptual framework of Governance of Arrival. The issues of a strained housing market and the integration of asylum seekers in it do not apply only to Leipzig, but shed light on similar developments in other European Cities.}, subject = {Stadtplanung}, language = {en} } @phdthesis{Wang, author = {Wang, Cuixia}, title = {Nanomechanical Resonators Based on Quasi-two-dimensional Materials}, doi = {10.25643/bauhaus-universitaet.3760}, url = {http://nbn-resolving.de/urn:nbn:de:gbv:wim2-20180709-37609}, school = {Bauhaus-Universit{\"a}t Weimar}, abstract = {Advances in nanotechnology lead to the development of nano-electro-mechanical systems (NEMS) such as nanomechanical resonators with ultra-high resonant frequencies. The ultra-high-frequency resonators have recently received significant attention for wide-ranging applications such as molecular separation, molecular transportation, ultra-high sensitive sensing, high-frequency signal processing, and biological imaging. It is well known that for micrometer length scale, first-principles technique, the most accurate approach, poses serious limitations for comparisons with experimental studies. For such larger size, classical molecular dynamics (MD) simulations are desirable, which require interatomic potentials. Additionally, a mesoscale method such as the coarse-grained (CG) method is another useful method to support simulations for even larger system sizes. Furthermore, quasi-two-dimensional (Q2D) materials have attracted intensive research interest due to their many novel properties over the past decades. However, the energy dissipation mechanisms of nanomechanical resonators based on several Q2D materials are still unknown. In this work, the addressed main issues include the development of the CG models for molybdenum disulphide (MoS2), investigation of the mechanism effects on black phosphorus (BP) nanoresonators and the application of graphene nanoresonators. The primary coverage and results of the dissertation are as follows: Method development. Firstly, a two-dimensional (2D) CG model for single layer MoS2 (SLMoS2) is analytically developed. The Stillinger-Weber (SW) potential for this 2D CG model is further parametrized, in which all SW geometrical parameters are determined analytically according to the equilibrium condition for each individual potential term, while the SW energy parameters are derived analytically based on the valence force field model. Next, the 2D CG model is further simplified to one-dimensional (1D) CG model, which describes the 2D SLMoS2 structure using a 1D chain model. This 1D CG model is applied to investigate the relaxed configuration and the resonant oscillation of the folded SLMoS2. Owning to the simplicity nature of the 1D CG model, the relaxed configuration of the folded SLMoS2 is determined analytically, and the resonant oscillation frequency is derived analytically. Considering the increasing interest in studying the properties of other 2D layered materials, and in particular those in the semiconducting transition metal dichalcogenide class like MoS2, the CG models proposed in current work provide valuable simulation approaches. Mechanism understanding. Two energy dissipation mechanisms of BP nanoresonators are focused exclusively, i.e. mechanical strain effects and defect effects (including vacancy and oxidation). Vacancy defect is intrinsic damping factor for the quality (Q)-factor, while mechanical strain and oxidation are extrinsic damping factors. Intrinsic dissipation (induced by thermal vibrations) in BP resonators (BPRs) is firstly investigated. Specifically, classical MD simulations are performed to examine the temperature dependence for the Q-factor of the single layer BPR (SLBPR) along the armchair and zigzag directions, where two-step fitting procedure is used to extract the frequency and Q-factor from the kinetic energy time history. The Q-factors of BPRs are evaluated through comparison with those of graphene and MoS2 nanoresonators. Next, effects of mechanical strain, vacancy and oxidation on BP nanoresonators are investigated in turn. Considering the increasing interest in studying the properties of BP, and in particular the lack of theoretical study for the BPRs, the results in current work provide a useful reference. Application. A novel application for graphene nanoresonators, using them to self-assemble small nanostructures such as water chains, is proposed. All of the underlying physics enabling this phenomenon is elucidated. In particular, by drawing inspiration from macroscale self-assembly using the higher order resonant modes of Chladni plates, classical MD simulations are used to investigate the self-assembly of water molecules using graphene nanoresonators. An analytic formula for the critical resonant frequency based on the interaction between water molecules and graphene is provided. Furthermore, the properties of the water chains assembled by the graphene nanoresonators are studied.}, subject = {Nanomechanik}, language = {en} } @article{VoelkerAlsaad, author = {V{\"o}lker, Conrad and Alsaad, Hayder}, title = {Simulating the human body's microclimate using automatic coupling of CFD and an advanced thermoregulation model}, series = {Indoor Air}, volume = {2018}, journal = {Indoor Air}, number = {28, Heft 3}, doi = {10.25643/bauhaus-universitaet.3851}, url = {http://nbn-resolving.de/urn:nbn:de:gbv:wim2-20190218-38517}, pages = {415 -- 425}, abstract = {This study aims to develop an approach to couple a computational fluid dynamics (CFD) solver to the University of California, Berkeley (UCB) thermal comfort model to accurately evaluate thermal comfort. The coupling was made using an iterative JavaScript to automatically transfer data for each individual segment of the human body back and forth between the CFD solver and the UCB model until reaching convergence defined by a stopping criterion. The location from which data are transferred to the UCB model was determined using a new approach based on the temperature difference between subsequent points on the temperature profile curve in the vicinity of the body surface. This approach was used because the microclimate surrounding the human body differs in thickness depending on the body segment and the surrounding environment. To accurately simulate the thermal environment, the numerical model was validated beforehand using experimental data collected in a climate chamber equipped with a thermal manikin. Furthermore, an example of the practical implementations of this coupling is reported in this paper through radiant floor cooling simulation cases, in which overall and local thermal sensation and comfort were investigated using the coupled UCB model.}, subject = {Numerische Str{\"o}mungssimulation}, language = {en} } @phdthesis{Vollmering, author = {Vollmering, Max}, title = {Damage Localization of Mechanical Structures by Subspace Identification and Krein Space Based H-infinity Estimation}, doi = {10.25643/bauhaus-universitaet.3772}, url = {http://nbn-resolving.de/urn:nbn:de:gbv:wim2-20180730-37728}, school = {Bauhaus-Universit{\"a}t Weimar}, pages = {205}, abstract = {This dissertation is devoted to the theoretical development and experimental laboratory verification of a new damage localization method: The state projection estimation error (SP2E). This method is based on the subspace identification of mechanical structures, Krein space based H-infinity estimation and oblique projections. To explain method SP2E, several theories are discussed and laboratory experiments have been conducted and analysed. A fundamental approach of structural dynamics is outlined first by explaining mechanical systems based on first principles. Following that, a fundamentally different approach, subspace identification, is comprehensively explained. While both theories, first principle and subspace identification based mechanical systems, may be seen as widespread methods, barely known and new techniques follow up. Therefore, the indefinite quadratic estimation theory is explained. Based on a Popov function approach, this leads to the Krein space based H-infinity theory. Subsequently, a new method for damage identification, namely SP2E, is proposed. Here, the introduction of a difference process, the analysis by its average process power and the application of oblique projections is discussed in depth. Finally, the new method is verified in laboratory experiments. Therefore, the identification of a laboratory structure at Leipzig University of Applied Sciences is elaborated. Then structural alterations are experimentally applied, which were localized by SP2E afterwards. In the end four experimental sensitivity studies are shown and discussed. For each measurement series the structural alteration was increased, which was successfully tracked by SP2E. The experimental results are plausible and in accordance with the developed theories. By repeating these experiments, the applicability of SP2E for damage localization is experimentally proven.}, subject = {Strukturmechanik}, language = {en} } @article{Vollmer, author = {Vollmer, Lisa}, title = {Mieter_innenproteste von den 1960er bis in die 1980er Jahre in der BRD. Von der Klassenallianz zur Aufspaltung und Einhegung ins neoliberale Projekt}, series = {sub\urban. zeitschrift f{\"u}r kritische stadtforschung}, volume = {2018}, journal = {sub\urban. zeitschrift f{\"u}r kritische stadtforschung}, number = {Band 6, Heft 2/3}, doi = {10.25643/bauhaus-universitaet.3829}, url = {http://nbn-resolving.de/urn:nbn:de:gbv:wim2-20181213-38290}, pages = {137 -- 148}, abstract = {Die sp{\"a}ten 1960er Jahre und vor allem die 1970er Jahre waren eine Hochphase der Mieter_innenproteste in der BRD. Dieser Beitrag verfolgt die These, dass die Krise der fordistischen Wohnraumversorgung in den 1960er Jahren, bzw. die von der Politik implementierten L{\"o}sungsstrategien dieser Krise, eine Klassenallianz in wohnungsbezogenen Protesten erm{\"o}glichte und, dass sich diese Klassenallianz im Laufe der 1970er und 1980er Jahre aufspaltete, was zur Einhegung des Protests in das entstehende neoliberale Projekt f{\"u}hrte. Im Folgenden beschreibe ich also zun{\"a}chst die Wohnungsfrage 1968 als Krise der fordistischen Wohnraumproduktion und damit die materielle Basis der Klassenallianz. Daran anschließend illustriere ich anhand von Protesten in den drei Bereichen Massenwohnungsbau, Sanierungsgebiete und Hausbesetzungen die Klassenallianz und vollziehe ich deren Aufspaltung nach. Und schließlich stelle ich die Frage, was heute aus dieser Geschichte gelernt werden kann.}, subject = {Soziale Bewegung}, language = {de} } @phdthesis{Vesper, author = {Vesper, Andreas}, title = {Entwicklung eines Berechnungsverfahrens zur Ermittlung der Kapazit{\"a}t in lichtsignalgeregelten Zufahrten mit zus{\"a}tzlichen Aufstellstreifen bei gleichzeitiger Freigabezeit}, doi = {10.25643/bauhaus-universitaet.3789}, url = {http://nbn-resolving.de/urn:nbn:de:gbv:wim2-20180925-37895}, school = {Bauhaus-Universit{\"a}t Weimar}, pages = {338}, abstract = {Im Rahmen der Dissertation ist ein analytisches Berechnungsverfahren zur Ermittlung der Kapazit{\"a}t in lichtsignalgeregelten Zufahrten mit zus{\"a}tzlichen Aufstellstreifen bei gleichzeitiger Freigabezeit entwickelt worden, dass sich durch folgende Eigenschaften auszeichnet: a) einfaches Berechnungsverfahren - Ansatz eines einfachen linearen Berechnungsansatzes, der auf den Grundzusammenh{\"a}ngen des Verkehrsablaufs in lichtsignalgeregelten Zufahrten aufbaut, b) breites Anwendungsgebiet - Berechnungsverfahren kann in Zufahrten mit bis zu zwei zus{\"a}tzlichen Aufstellstreifen angewendet werden, c) hohe Genauigkeit - Im Rahmen eines direkten Vergleichs konnte u. a. gezeigt werden, dass mit dem hergeleiteten analytischen Berechnungsverfahren genauere Kapazit{\"a}tswerte ermittelt werden k{\"o}nnen, als mit dem Berechnungsverfahren nach HBS 2015.}, subject = {Verkehrssignalanlage}, language = {de} } @unpublished{SteinerBourinetLahmer, author = {Steiner, Maria and Bourinet, Jean-Marc and Lahmer, Tom}, title = {An adaptive sampling method for global sensitivity analysis based on least-squares support vector regression}, doi = {10.25643/BAUHAUS-UNIVERSITAET.3832}, url = {http://nbn-resolving.de/urn:nbn:de:gbv:wim2-20181218-38320}, pages = {1 -- 33}, abstract = {In the field of engineering, surrogate models are commonly used for approximating the behavior of a physical phenomenon in order to reduce the computational costs. Generally, a surrogate model is created based on a set of training data, where a typical method for the statistical design is the Latin hypercube sampling (LHS). Even though a space filling distribution of the training data is reached, the sampling process takes no information on the underlying behavior of the physical phenomenon into account and new data cannot be sampled in the same distribution if the approximation quality is not sufficient. Therefore, in this study we present a novel adaptive sampling method based on a specific surrogate model, the least-squares support vector regresson. The adaptive sampling method generates training data based on the uncertainty in local prognosis capabilities of the surrogate model - areas of higher uncertainty require more sample data. The approach offers a cost efficient calculation due to the properties of the least-squares support vector regression. The opportunities of the adaptive sampling method are proven in comparison with the LHS on different analytical examples. Furthermore, the adaptive sampling method is applied to the calculation of global sensitivity values according to Sobol, where it shows faster convergence than the LHS method. With the applications in this paper it is shown that the presented adaptive sampling method improves the estimation of global sensitivity values, hence reducing the overall computational costs visibly.}, subject = {Approximation}, language = {en} } @phdthesis{Skivko, author = {Skivko, Maria}, title = {Fashion in the City and The City in Fashion: Urban Representation in Fashion Magazines}, doi = {10.25643/bauhaus-universitaet.3726}, url = {http://nbn-resolving.de/urn:nbn:de:gbv:wim2-20180210-37262}, school = {Bauhaus-Universit{\"a}t Weimar}, abstract = {This dissertation concerns the changing role of fashion in the context of modern cities. In approaching this process, the research investigates the media discourse based on representations of fashion by cities and of cities by fashion. Moreover, this research focuses on fashion understood as a multidimensional phenomenon that aims to provide an explanation of urban spaces through fashion terms, actions, and garments. Additionally, cities are considered from the cultural geography approach that highlights the cultural component of urban spaces expressed in social and cultural practices in physical reality. Following this idea, it is suggested here that fashion today not only participates in the urban life as its significant component but also creates city images and representations of urban lifestyle through the fashion paradigm. In other words, fashion redefines urban spaces; at the same time, urban spaces are interpreted as a stage for fashion processes. By integrating in social research the fields of urban studies and fashion studies, this dissertation offers the discussion considering the fashion phenomenon not only as an urban phenomenon of modern reality. On the one hand, such discussion concerns the re-conceptualization of urban phenomena by the fashion influence; on the other hand, it relates the re-contextualization of fashion in a city. The empirical focus is based on the media context of fashion magazines in which variety of possibilities to represent fashion and cities lead to promising interpretations and analysis. The idea of representation specifies the ways of constructing the notion of urban space as fashionable space and the notion of fashion as placed in the urban context.}, subject = {Stadtentwicklung}, language = {en} }