@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} } @article{MorgenthalEickRauetal., author = {Morgenthal, Guido and Eick, Jan Frederick and Rau, Sebastian and Taraben, Jakob}, title = {Wireless Sensor Networks Composed of Standard Microcomputers and Smartphones for Applications in Structural Health Monitoring}, series = {Sensors - Special Issue Selected Papers from 7th Asia-Pacific Workshop on Structural Health Monitoring}, volume = {2019}, journal = {Sensors - Special Issue Selected Papers from 7th Asia-Pacific Workshop on Structural Health Monitoring}, number = {Volume 19, Issue 9, 2070}, publisher = {MDPI}, doi = {10.3390/s19092070}, url = {http://nbn-resolving.de/urn:nbn:de:gbv:wim2-20190514-39123}, pages = {22}, abstract = {Wireless sensor networks have attracted great attention for applications in structural health monitoring due to their ease of use, flexibility of deployment, and cost-effectiveness. This paper presents a software framework for WiFi-based wireless sensor networks composed of low-cost mass market single-board computers. A number of specific system-level software components were developed to enable robust data acquisition, data processing, sensor network communication, and timing with a focus on structural health monitoring (SHM) applications. The framework was validated on Raspberry Pi computers, and its performance was studied in detail. The paper presents several characteristics of the measurement quality such as sampling accuracy and time synchronization and discusses the specific limitations of the system. The implementation includes a complementary smartphone application that is utilized for data acquisition, visualization, and analysis. A prototypical implementation further demonstrates the feasibility of integrating smartphones as data acquisition nodes into the network, utilizing their internal sensors. The measurement system was employed in several monitoring campaigns, three of which are documented in detail. The suitability of the system is evaluated based on comparisons of target quantities with reference measurements. The results indicate that the presented system can robustly achieve a measurement performance commensurate with that required in many typical SHM tasks such as modal identification. As such, it represents a cost-effective alternative to more traditional monitoring solutions.}, subject = {Structural Health Monitoring}, language = {en} } @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} } @inproceedings{DokhanchiArnoldVogeletal., author = {Dokhanchi, Najmeh Sadat and Arnold, J{\"o}rg and Vogel, Albert and V{\"o}lker, Conrad}, title = {Acoustic Travel-Time Tomography: Optimal Positioning of Transceiver and Maximal Sound-Ray Coverage of the Room}, series = {Fortschritte der Akustik - DAGA 2019}, booktitle = {Fortschritte der Akustik - DAGA 2019}, doi = {10.25643/bauhaus-universitaet.3877}, url = {http://nbn-resolving.de/urn:nbn:de:gbv:wim2-20190408-38778}, pages = {4}, abstract = {Acoustic travel-time tomography (ATOM) determines the distribution of the temperature in a propagation medium by measuring the travel-time of acoustic signals between transmitters and receivers. To employ ATOM for indoor climate measurements, the impulse responses have been measured in the climate chamber lab of the Bauhaus-University Weimar and compared with the theoretical results of its image source model (ISM). A challenging task is distinguishing the reflections of interest in the reflectogram when the sound rays have similar travel-times. This paper presents a numerical method to address this problem by finding optimal positions of transmitter and receiver, since they have a direct impact on the distribution of travel times. These optimal positions have the minimum number of simultaneous arrival time within a threshold level. Moreover, for the tomographic reconstruction, when some of the voxels remain empty of sound-rays, it leads to inaccurate determination of the air temperature within those voxels. Based on the presented numerical method, the number of empty tomographic voxels are minimized to ensure the best sound-ray coverage of the room. Subsequently, a spatial temperature distribution is estimated by simultaneous iterative reconstruction technique (SIRT). The experimental set-up in the climate chamber verifies the simulation results.}, subject = {Bauphysik}, language = {en} } @article{BielikSchneiderKuligaetal., author = {Bielik, Martin and Schneider, Sven and Kuliga, Saskia and Griego, Danielle and Ojha, Varun and K{\"o}nig, Reinhard and Schmitt, Gerhard and Donath, Dirk}, title = {Examining Trade-Offs between Social, Psychological, and Energy Potential of Urban Form}, series = {ISPRS International Journal of Geo-Information}, volume = {2019}, journal = {ISPRS International Journal of Geo-Information}, editor = {Resch, Bernd and Szell, Michael}, doi = {10.3390/ijgi8020052}, url = {http://nbn-resolving.de/urn:nbn:de:gbv:wim2-20190408-38695}, abstract = {Urban planners are often challenged with the task of developing design solutions which must meet multiple, and often contradictory, criteria. In this paper, we investigated the trade-offs between social, psychological, and energy potential of the fundamental elements of urban form: the street network and the building massing. Since formal mehods to evaluate urban form from the psychological and social point of view are not readily available, we developed a methodological framework to quantify these criteria as the first contribution in this paper. To evaluate the psychological potential, we conducted a three-tiered empirical study starting from real world environments and then abstracting them to virtual environments. In each context, the implicit (physiological) response and explicit (subjective) response of pedestrians were measured. To quantify the social potential, we developed a street network centrality-based measure of social accessibility. For the energy potential, we created an energy model to analyze the impact of pure geometric form on the energy demand of the building stock. The second contribution of this work is a method to identify distinct clusters of urban form and, for each, explore the trade-offs between the select design criteria. We applied this method to two case studies identifying nine types of urban form and their respective potential trade-offs, which are directly applicable for the assessment of strategic decisions regarding urban form during the early planning stages.}, subject = {Planung}, language = {en} } @article{KavrakovLegatiukGuerlebecketal., author = {Kavrakov, Igor and Legatiuk, Dmitrii and G{\"u}rlebeck, Klaus and Morgenthal, Guido}, title = {A categorical perspective towards aerodynamic models for aeroelastic analyses of bridge decks}, series = {Royal Society Open Science}, journal = {Royal Society Open Science}, number = {Volume 6, Issue 3}, doi = {/10.1098/rsos.181848}, url = {http://nbn-resolving.de/urn:nbn:de:gbv:wim2-20190314-38656}, pages = {20}, abstract = {Reliable modelling in structural engineering is crucial for the serviceability and safety of structures. A huge variety of aerodynamic models for aeroelastic analyses of bridges poses natural questions on their complexity and thus, quality. Moreover, a direct comparison of aerodynamic models is typically either not possible or senseless, as the models can be based on very different physical assumptions. Therefore, to address the question of principal comparability and complexity of models, a more abstract approach, accounting for the effect of basic physical assumptions, is necessary. This paper presents an application of a recently introduced category theory-based modelling approach to a diverse set of models from bridge aerodynamics. Initially, the categorical approach is extended to allow an adequate description of aerodynamic models. Complexity of the selected aerodynamic models is evaluated, based on which model comparability is established. Finally, the utility of the approach for model comparison and characterisation is demonstrated on an illustrative example from bridge aeroelasticity. The outcome of this study is intended to serve as an alternative framework for model comparison and impact future model assessment studies of mathematical models for engineering applications.}, subject = {Br{\"u}cke}, language = {en} } @unpublished{RadmardRahmaniKoenke, author = {Radmard Rahmani, Hamid and K{\"o}nke, Carsten}, title = {Passive Control of Tall Buildings Using Distributed Multiple Tuned Mass Dampers}, doi = {10.25643/bauhaus-universitaet.3859}, url = {http://nbn-resolving.de/urn:nbn:de:gbv:wim2-20190311-38597}, pages = {43}, abstract = {The vibration control of the tall building during earthquake excitations is a challenging task due to their complex seismic behavior. This paper investigates the optimum placement and properties of the Tuned Mass Dampers (TMDs) in tall buildings, which are employed to control the vibrations during earthquakes. An algorithm was developed to spend a limited mass either in a single TMD or in multiple TMDs and distribute them optimally over the height of the building. The Non-dominated Sorting Genetic Algorithm (NSGA - II) method was improved by adding multi-variant genetic operators and utilized to simultaneously study the optimum design parameters of the TMDs and the optimum placement. The results showed that under earthquake excitations with noticeable amplitude in higher modes, distributing TMDs over the height of the building is more effective in mitigating the vibrations compared to the use of a single TMD system. From the optimization, it was observed that the locations of the TMDs were related to the stories corresponding to the maximum modal displacements in the lower modes and the stories corresponding to the maximum modal displacements in the modes which were highly activated by the earthquake excitations. It was also noted that the frequency content of the earthquake has significant influence on the optimum location of the TMDs.}, subject = {Schwingungsd{\"a}mpfer}, 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} }