The 10 most recently published documents
Auguste Rodins Weimarer Eva
(2018)
The purpose of this study is to develop self-contained methods for obtaining smooth meshes which are compatible with isogeometric analysis (IGA). The study contains three main parts. We start by developing a better understanding of shapes and splines through the study of an image-related problem. Then we proceed towards obtaining smooth volumetric meshes of the given voxel-based images. Finally, we treat the smoothness issue on the multi-patch domains with C1 coupling. Following are the highlights of each part.
First, we present a B-spline convolution method for boundary representation of voxel-based images. We adopt the filtering technique to compute the B-spline coefficients and gradients of the images effectively. We then implement the B-spline convolution for developing a non-rigid images registration method. The proposed method is in some sense of “isoparametric”, for which all the computation is done within the B-splines framework. Particularly, updating the images by using B-spline composition promote smooth transformation map between the images. We show the possible medical applications of our method by applying it for registration of brain images.
Secondly, we develop a self-contained volumetric parametrization method based on the B-splines boundary representation. We aim to convert a given voxel-based data to a matching C1 representation with hierarchical cubic splines. The concept of the osculating circle is employed to enhance the geometric approximation, where it is done by a single template and linear transformations (scaling, translations, and rotations) without the need for solving an optimization problem. Moreover, we use the Laplacian smoothing and refinement techniques to avoid irregular meshes and to improve mesh quality. We show with several examples that the method is capable of handling complex 2D and 3D configurations. In particular, we parametrize the 3D Stanford bunny which contains irregular shapes and voids.
Finally, we propose the B´ezier ordinates approach and splines approach for C1 coupling. In the first approach, the new basis functions are defined in terms of the B´ezier Bernstein polynomials. For the second approach, the new basis is defined as a linear combination of C0 basis functions. The methods are not limited to planar or bilinear mappings. They allow the modeling of solutions to fourth order partial differential equations (PDEs) on complex geometric domains, provided that the given patches are G1
continuous. Both methods have their advantages. In particular, the B´ezier approach offer more degree of freedoms, while the spline approach is more computationally efficient. In addition, we proposed partial degree elevation to overcome the C1-locking issue caused by the over constraining of the solution space. We demonstrate the potential of the resulting C1 basis functions for application in IGA which involve fourth order PDEs such as those appearing in Kirchhoff-Love shell models, Cahn-Hilliard phase field application, and biharmonic problems.
In this research, an attempt was made to reduce the dimension of wavelet-ANFIS/ANN (artificial neural network/adaptive neuro-fuzzy inference system) models toward reliable forecasts as well as to decrease computational cost. In this regard, the principal component analysis was performed on the input time series decomposed by a discrete wavelet transform to feed the ANN/ANFIS models. The models were applied for dissolved oxygen (DO) forecasting in rivers which is an important variable affecting aquatic life and water quality. The current values of DO, water surface temperature, salinity, and turbidity have been considered as the input variable to forecast DO in a three-time step further. The results of the study revealed that PCA can be employed as a powerful tool for dimension reduction of input variables and also to detect inter-correlation of input variables. Results of the PCA-wavelet-ANN models are compared with those obtained from wavelet-ANN models while the earlier one has the advantage of less computational time than the later models. Dealing with ANFIS models, PCA is more beneficial to avoid wavelet-ANFIS models creating too many rules which deteriorate the efficiency of the ANFIS models. Moreover, manipulating the wavelet-ANFIS models utilizing PCA leads to a significant decreasing in computational time. Finally, it was found that the PCA-wavelet-ANN/ANFIS models can provide reliable forecasts of dissolved oxygen as an important water quality indicator in rivers.
This study investigates the performance of two systems: personalized ventilation (PV) and ductless personalized ventilation (DPV). Even though the literature indicates a compelling performance of PV, it is not often used in practice due to its impracticality. Therefore, the present study assesses the possibility of replacing the inflexible PV with DPV in office rooms equipped with displacement ventilation (DV) in the summer season. Numerical simulations were utilized to evaluate the inhaled concentration of pollutants when PV and DPV are used. The systems were compared in a simulated office with two occupants: a susceptible occupant and a source occupant. Three types of pollution were simulated: exhaled infectious air, dermally emitted contamination, and room contamination from a passive source. Results indicated that PV improved the inhaled air quality regardless of the location of the pollution source; a higher PV supply flow rate positively impacted the inhaled air quality. Contrarily, the performance of DPV was highly sensitive to the source location and the personalized flow rate. A higher DPV flow rate tends to decrease the inhaled air quality due to increased mixing of pollutants in the room. Moreover, both systems achieved better results when the personalized system of the source occupant was switched off.
Die Ruine der Barfüßerkirche in Erfurt stellt eine der letzten Erinnerungen an die Zerstörungen der Stadt im Zweiten Weltkrieg dar. Sie wird bis heute temporär und saisonal kulturell genutzt. Im Rahmen eines Studienprojektes im Sommersemester 2019 wurden an der Bauhaus-Universität Weimar, betreut durch die Professur Denkmalpflege und Baugeschichte und unterstützt vom Initiativkreis Barfüßerkirche, Nutzungskonzepte für ein Museum für Mittelalterkunst und für einen Tagungsort untersucht. Der vorliegende Band dokumentiert die 14 studentischen Entwürfe, die für ein Weiterbauen an der Barfüßerkirche entstanden sind.
The thesis concerns a work of urban history intended not to describe the city but rather to interpret it. By doing so, I have interpreted the city by means of the role played by the so-called ‘great property’ in the European city-making process during the last three decades of the 20th century, specifically focused on the concrete case of military properties in Italy. I have also considered the role played by other kinds of great properties, i.e. industries and railway, which previously acted in the production of the built environment in a different way respect to the military one. As all of them have as common denominator the fact of being ‘capital in land’, I analysed great industrial and railway properties in order to extrapolate a methodology which helped me to interpret the relationship between military properties and city-making process in Europe in the late 20th century.
I have analysed the relationship between the capital in land and the city-making process on the ground of the understanding the interrelation between the great property, the urban development, and the agents involved in the urban and territorial planning. Here I have showed that urban planning is not the decisive factor influencing the citymaking process, but instead the power held by the capital in land. I have found that is the great property the trigger of the creation of new ‘areas of centrality’ intended as large areas for consumerism. As far as the role played by great property is concerned, I have also discovered that it has evolved over time. Originally, industrial and railway properties have been regenerated into a wide range of new profit-driven spaces; successively, I have found out that most of the regeneration of military premises aimed to materialise areas of centrality. The way of interpreting this factor has been based on focusing my attention on the military premises in Italy: I have classified their typology when they have been built and, most importantly, when they have been regenerated into new areas of centrality.
Welfare‐state transformation and entrepreneurial urban politics in Western welfare states since the late 1970s have yielded converging trends in the transformation of the dominant Fordist paradigm of social housing in terms of its societal function and institutional and spatial form. In this article I draw from a comparative case study on two cities in Germany to show that the resulting new paradigm is simultaneously shaped by the idiosyncrasies of the country's national housing regime and local housing policies. While German governments have successively limited the societal function of social housing as a legitimate instrument only for addressing exceptional housing crises, local policies on providing and organizing social housing within this framework display significant variation. However, planning and design principles dominating the spatial forms of social housing have been congruent. They may be interpreted as both an expression of the marginalization of social housing within the restructured welfare housing regime and a tool of its implementation according to the logics of entrepreneurial urban politics.
A new large‐field, high‐sensitivity, single‐mirror coincident schlieren optical instrument has been installed at the Bauhaus‐Universität Weimar for the purpose of indoor air research. Its performance is assessed by the non‐intrusive measurement of the thermal plume of a heated manikin. The schlieren system produces excellent qualitative images of the manikin's thermal plume and also quantitative data, especially schlieren velocimetry of the plume's velocity field that is derived from the digital cross‐correlation analysis of a large time sequence of schlieren images. The quantitative results are compared with thermistor and hot‐wire anemometer data obtained at discrete points in the plume. Good agreement is obtained, once the differences between path‐averaged schlieren data and planar anemometry data are reconciled.
The economic losses from earthquakes tend to hit the national economy considerably; therefore, models that are capable of estimating the vulnerability and losses of future earthquakes are highly consequential for emergency planners with the purpose of risk mitigation. This demands a mass prioritization filtering of structures to identify vulnerable buildings for retrofitting purposes. The application of advanced structural analysis on each building to study the earthquake response is impractical due to complex calculations, long computational time, and exorbitant cost. This exhibits the need for a fast, reliable, and rapid method, commonly known as Rapid Visual Screening (RVS). The method serves as a preliminary screening platform, using an optimum number of seismic parameters of the structure and predefined output damage states. In this study, the efficacy of the Machine Learning (ML) application in damage prediction through a Support Vector Machine (SVM) model as the damage classification technique has been investigated. The developed model was trained and examined based on damage data from the 1999 Düzce Earthquake in Turkey, where the building’s data consists of 22 performance modifiers that have been implemented with supervised machine learning.