@phdthesis{Zierold2004, author = {Zierold, Sabine}, title = {Der mediale Raum der Architektur}, doi = {10.25643/bauhaus-universitaet.767}, url = {http://nbn-resolving.de/urn:nbn:de:gbv:wim2-20060806-8106}, school = {Bauhaus-Universit{\"a}t Weimar}, year = {2004}, abstract = {Der architektonische Raum wird als ein Medium der Kommunikation im Kontext der >neuen< Medien begriffen, aus der Erkenntnis, dass er schon immer ein Medium war und aus einer komplexen Medienstruktur in Abh{\"a}ngigkeit von anderen Medien besteht. Im Prozess von Handlung und Kommunikation ist der architektonische Raum das Medium, das r{\"a}umliche N{\"a}he von Individuen {\"u}ber alle Sinne und das Bewusstsein gleichzeitig intensiv erm{\"o}glicht. Der architektonische Raum als immersives Kommunikationsmedium erreicht im Zeitalter der >neuen< Medien eine neue Dimension, indem mehr und andere Wirklichkeitsalternativen der Kommunikation zur Verf{\"u}gung stehen. N. Luhmann folgend, wird die Architektur aus der Sicht der Form/Medium-Differenz systemtheoretisch als strukturierter M{\"o}glichkeitsraum betrachtet. Der Raum ist das Medium f{\"u}r Formen des architektonischen Raumes, in dem Architektur {\"u}berhaupt erst wirksam wird. Umgekehrt sind die Formen des architektonischen Raumes Medien f{\"u}r die Wahrnehmung einer Vielzahl von r{\"a}umlichen Wirklichkeiten. Eine Fassade aus Stein oder Glas ist gebaute Form und kann als Medium Information kommunizieren. Medien werden ihrer Bestimmung um so besser gerecht, je mehr sie sich der Aufmerksamkeit entziehen und wie transparente Fenster hinter der Oberfl{\"a}che der sinnlichen Wahrnehmung zur{\"u}cktreten. Als >unwahrnehmbares< Medium ist der architektonische Raum damit eine hintergr{\"u}ndige >Wirkungsmacht<, eine B{\"u}hne f{\"u}r die Entfaltung von Wirkung, Atmosph{\"a}re und Bewegung. Seine physische Wirklichkeit war schon immer durch virtuelle Wirklichkeiten oder Realit{\"a}ten entgrenzt, die durch Techniken und Technologien der Simulation als k{\"u}nstliche Welten wahrnehmbar und kommunizierbar werden. Dies kann an tradierten Beispielen der gotischen Kathedrale, dem Panorama, den panoptischen R{\"a}umen, dem Theater, Kino oder den kontinuierlichen R{\"a}umen von der Moderne bis heute aufgezeigt weren. Virtuelle R{\"a}ume gotischer Glasbilder oder barocker Decken- und Wandbilder im Medium des architektonischen Raumes sind uns gel{\"a}ufig. Die Immersion, das Eintauchen in diese virtuellen Wirklichkeitssp{\"a}ren l{\"o}st die Wahrnehmung der eigenen k{\"o}rperlichen Pr{\"a}senz in ihnen aus. Das Potential des virtuellen Raumes der Architektur besteht im Vergleich zu anderen virtuellen Realit{\"a}ten von Text, Bild oder digitalen Medien in seiner Gebundenheit an die physische, r{\"a}umliche Reizstruktur, der er die Eindringlichkeit und Komplexit{\"a}t seiner Wirkung verdankt. Es werden unterschiedliche Wechselwirkungen und gemeinsame Entwicklungen von zeitgen{\"o}ssischen Beispielen der Architektur mit den >neuen< Medien aufgezeigt. In der »sensitiven Wand« wird die physische Raumgrenze durch die Integration neuer Techniken und Technologien digitaler, elektronischer Medien etwas extrem Flexibles und Formbares in Interaktion mit dem Benutzer. Der H2O Pavillon (Oosterhuis und NOX, 1997) ist ein Beispiel daf{\"u}r. Der ausgepr{\"a}gt polysensorische Immersionsraum steht f{\"u}r die Einheit von digitaler und architektonischer Simulation. Die metaphorische Welt von H{\"o}hle und Quelle des Thermalbades Vals (P.Zumthor, 1996) ist die r{\"a}umliche Reflexion auf die metaphorische Struktur virtueller R{\"a}ume der >neuen< Medien. Die simulierte Wirklichkeit in den Medien Wasser, Stein und architektonischer Raum produziert sch{\"o}pferisch den polysensorischen immersiven Zugang in die virtuellen Welten >authentischer< physischer Umgebung. Das >Sichtbare< im Medium Raum der Architektur ist ohne das >Unsichtbare< nicht zu begreifen bzw. das sinnlich Wahrnehmbare nicht ohne das Unwahrnehmbare. Das Erkennen dieser Relation von Form und Medium erm{\"o}glicht die Formulierung des neuen Begriffes des medialen Raumes der Architektur, der zur Basis f{\"u}r eine Medientheorie der Architektur wird, als Sichtweise der Entgrenzung des physischen Raumes durch den virtuellen Raum f{\"u}r die subjektive Wahrnehmung, Handlung und Kommunikation.}, subject = {Architektur}, language = {de} } @inproceedings{Zaneldin2004, author = {Zaneldin, Essam}, title = {Investigate the Impact of Different Resource Allocation Strategies on the Design of Building Projects Using Simulation}, doi = {10.25643/bauhaus-universitaet.165}, url = {http://nbn-resolving.de/urn:nbn:de:gbv:wim2-20111215-1658}, year = {2004}, abstract = {The design of building projects involves several types of resources such as architects, structural engineers, mechanical engineers, electrical engineers, and draftsmen, among others. For design firms to stay in business in this very competitive market, they need to manage their resources in a way that improves productivity and cost effectiveness. This task, however, is not simple and requires thorough analysis of process-level operations, resource use, and productivity. Typically, these operational aspects are the responsibility of the design office manager who assigns available resources to the different design projects to save time and lower design expenses. It is noted that limited studies have been carried out in the literature to model overall organizational operations and behavioral aspects, particularly in firms specialized in the design of building projects. In an effort to simplify the modeling process, a simplified modeling and simulation tool is used in this research. A simulation model representing an actual design office was developed assuming that the office performs designs for small, medium, and large size building projects. The developed model was used to simulate several alternatives and examine various resource assignment strategies. The simulation was conducted over ten years and the resulting productivity and income was measured.}, subject = {Baubetrieb}, language = {en} } @article{Volkova2004, author = {Volkova, Viktorija}, title = {The analysis of dynamic behaviour of pre-stressed systems under polyharmonic excitations}, doi = {10.25643/bauhaus-universitaet.265}, url = {http://nbn-resolving.de/urn:nbn:de:gbv:wim2-20111215-2656}, year = {2004}, abstract = {Pre-stressed structural elements are widely used in large-span structures. As a rule, they have higher stiffness characteristics. Pre-stressed rods can be applied as girders of different purpose, and as their separate parts, e.g. rods of trusses and frames. Among numerous ways of prestressing the compression of girders, trusses, and frames by tightenings from high-strength materials is under common application.}, subject = {Verkehrsplanung}, language = {en} } @article{VogelBreitMaerki2004, author = {Vogel, Manfred and Breit, Manfred and M{\"a}rki, Fabian}, title = {Optimization of 4D Process Planning using Genetic Algorithms}, doi = {10.25643/bauhaus-universitaet.236}, url = {http://nbn-resolving.de/urn:nbn:de:gbv:wim2-20111215-2360}, year = {2004}, abstract = {The presented work focuses on the presentation of a discrete event simulator which can be used for automated sequencing and optimization of building processes. The sequencing is based on the commonly used component-activity-resource relations taking structural and process constraints into account. For the optimization a genetic algorithm approach was developed, implemented and successfully applied to several real life steel constructions. In this contribution we discuss the application of the discrete event simulator including its optimization capabilities on a 4D process model of a steel structure of an automobile recycling facility.}, subject = {Produktmodell}, language = {en} } @article{vanTreeckRank2004, author = {van Treeck, Christoph and Rank, Ernst}, title = {Analysis of building structure and topology based on Graph Theory}, doi = {10.25643/bauhaus-universitaet.230}, url = {http://nbn-resolving.de/urn:nbn:de:gbv:wim2-20111215-2308}, year = {2004}, abstract = {Individual views on a building product of people involved in the design process imply different models for planning and calculation. In order to interpret these geometrical, topological and semantical data of a building model we identify a structural component graph, a graph of room faces, a room graph and a relational object graph as aids and we explain algorithms to derive these relations. The application of the technique presented is demonstrated by the analysis and discretization of a sample model in the scope of building energy simulation.}, subject = {Produktmodell}, language = {en} } @phdthesis{Unger2009, author = {Unger, J{\"o}rg F.}, title = {Neural networks in a multiscale approach for concrete}, doi = {10.25643/bauhaus-universitaet.1392}, url = {http://nbn-resolving.de/urn:nbn:de:gbv:wim2-20090626-14763}, school = {Bauhaus-Universit{\"a}t Weimar}, year = {2009}, abstract = {From a macroscopic point of view, failure within concrete structures is characterized by the initiation and propagation of cracks. In the first part of the thesis, a methodology for macroscopic crack growth simulations for concrete structures using a cohesive discrete crack approach based on the extended finite element method is introduced. Particular attention is turned to the investigation of criteria for crack initiation and crack growth. A drawback of the macroscopic simulation is that the real physical phenomena leading to the nonlinear behavior are only modeled phenomenologically. For concrete, the nonlinear behavior is characterized by the initiation of microcracks which coalesce into macroscopic cracks. In order to obtain a higher resolution of this failure zones, a mesoscale model for concrete is developed that models particles, mortar matrix and the interfacial transition zone (ITZ) explicitly. The essential features are a representation of particles using a prescribed grading curve, a material formulation based on a cohesive approach for the ITZ and a combined model with damage and plasticity for the mortar matrix. Compared to numerical simulations, the response of real structures exhibits a stochastic scatter. This is e.g. due to the intrinsic heterogeneities of the structure. For mesoscale models, these intrinsic heterogeneities are simulated by using a random distribution of particles and by a simulation of spatially variable material parameters using random fields. There are two major problems related to numerical simulations on the mesoscale. First of all, the material parameters for the constitutive description of the materials are often difficult to measure directly. In order to estimate material parameters from macroscopic experiments, a parameter identification procedure based on Bayesian neural networks is developed which is universally applicable to any parameter identification problem in numerical simulations based on experimental results. This approach offers information about the most probable set of material parameters based on experimental data and information about the accuracy of the estimate. Consequently, this approach can be used a priori to determine a set of experiments to be carried out in order to fit the parameters of a numerical model to experimental data. The second problem is the computational effort required for mesoscale simulations of a full macroscopic structure. For this purpose, a coupling between mesoscale and macroscale model is developed. Representative mesoscale simulations are used to train a metamodel that is finally used as a constitutive model in a macroscopic simulation. Special focus is placed on the ability of appropriately simulating unloading.}, subject = {Beton}, language = {en} } @article{StaubFrench2004, author = {Staub-French, Sheryl}, title = {Feature-based Product Modeling for Building Construction}, doi = {10.25643/bauhaus-universitaet.233}, url = {http://nbn-resolving.de/urn:nbn:de:gbv:wim2-20111215-2331}, year = {2004}, abstract = {Current building product models explicitly represent components, attributes of components, and relationships between components. These designer-focused product models, however, do not represent many of the design conditions that are important for construction, such as component similarity, uniformity, and penetrations. Current design and construction tools offer limited support for detecting these construction-specific design conditions. This paper describes the ontology we developed using the manufacturing concept of features to represent the design conditions that are important for construction. The feature ontology provides the blueprint for the additions and changes needed to transform a standard product model into a constructionspecific product model. The ontology formalizes three classes of features, defines the attributes and functions of each feature type, and represents the relationships between features explicitly. The descriptive semantics of the ontology allows practitioners to represent their varied preferences for naming features, specifying features that result from component intersections and the similarity of components, and grouping features that affect a specific construction domain. A software prototype that implements the ontology enables practitioners to transform designer-focused product models into feature-based product models that represent the construction perspective.}, subject = {Produktmodell}, language = {en} } @article{ShihLee2004, author = {Shih, Naai-Jung and Lee, Wen-Pang}, title = {Particle Simulation and Evaluation of Personal Exposure to Contaminant Sources in an Elevation Space}, doi = {10.25643/bauhaus-universitaet.237}, url = {http://nbn-resolving.de/urn:nbn:de:gbv:wim2-20111215-2376}, year = {2004}, abstract = {An elevator, which figures a small volume, is normally used by everyone for a short period of time and equipped with simple ventilation system..Any contaminant released within it may cause serious problem. This research adapt a fire and smoke simulation software (FDS) into non-fire indoor airflow scario. Differently from previous research, particles are chosen as a risk evalution unit. A personal and multi-personal exposure model is proposed. The model takes the influence of the human thermal boundary, coughing, inhalation, exhalation, standing position, and the fan factor into account. The model is easy-to-use and suitable for the design of elevator system in practice.}, subject = {Produktmodell}, language = {en} } @article{SemenovAlekseevaTarlapan2004, author = {Semenov, Vitaly and Alekseeva, Elena and Tarlapan, Oleg}, title = {Virtual Construction using Map-based Approach}, doi = {10.25643/bauhaus-universitaet.244}, url = {http://nbn-resolving.de/urn:nbn:de:gbv:wim2-20111215-2447}, year = {2004}, abstract = {The paper presents a general map-based approach to prototyping of products in virtual reality environments. Virtual prototyping of products is considered as a consistent simulation and visualization process mapping the source product model into its target visual representations. The approach enables to interrelate formally the product and visual information models with each other by defining mapping rules, to specify a prototyping scenario as a composition of map instances, and then to explore particular product models in virtual reality environments by interpreting the composed scenario. Having been realized, the proposed approach provides for the strongly formalized method and the common software framework to build virtual prototyping applications. As a result, the applications gain in expressiveness, reusability and reliability, as well as take on additional runtime flexibility...}, subject = {Produktmodell}, language = {en} } @phdthesis{Schneider, author = {Schneider, Jens}, title = {Untersuchungen zum Alterungsverhalten und zur Langzeitstabilit{\"a}t von Y-TZP/Al2O3-Dispersionskeramiken (ATZ) f{\"u}r die Anwendung in der H{\"u}ft-Endoprothetik}, doi = {10.25643/bauhaus-universitaet.1776}, url = {http://nbn-resolving.de/urn:nbn:de:gbv:wim2-20121130-17761}, school = {Bauhaus-Universit{\"a}t Weimar}, pages = {151}, abstract = {6 Zusammenfassung und Ausblick Die hydrothermal induzierte Phasentransformation konnte f{\"u}r ATZ-Keramik mit tiefenge-mittelten und tiefenaufgel{\"o}sten Methoden charkterisiert und quantifiziert werden. Die zeit- und temperaturabh{\"a}ngige Alterungskinetik von ATZ wurde durch neun Tempera-turstufen in einem Temperaturbereich von 50 °C bis 134 °C untersucht und die kinetischen Parameter nummerisch bestimmt. F{\"u}r 3Y-TZP wurde diese Prozedur bei drei Temperaturen im Temperaturbereich von 70 °C bis 134 °C angewendet. Aufgrund des ARRHENIUS-Verhaltens der Umwandlungskinetik konnte der zeitliche Verlauf der isotherm stattfinden-den hydrothermal induzierten Phasentransformation bei K{\"o}rpertemperatur simuliert wer-den. Die Simulation dient zur Bewertung der Langzeitstabilit{\"a}t von medizinischen Implanta-ten aus ATZ bzw. 3Y-TZP. Die Untersuchungen wurden in Wasser und in Wasserdampf bzw. wasserdampfges{\"a}ttigter Luft durchgef{\"u}hrt. Die Langzeitsimulation f{\"u}r 3Y-TZP wurde an-hand von Explantat-Untersuchungen verifiziert. ATZ zeigt gegen{\"u}ber 3Y-TZP eine h{\"o}here Alterungsstabilit{\"a}t bezogen auf die zeitliche Ent-wicklung der monoklinen Phase. Im Hinblick auf die Oberfl{\"a}chenh{\"a}rte, die durch die Pha-senumwandlung stark beeinflusst wird, erweist sich ATZ {\"u}ber einen langen Alterungszeit-raum stabiler als 3Y-TZP. Bis zu einem monoklinen Gehalt von 40 \% beweist ATZ einen deutlichen H{\"a}rtevorteil gegen{\"u}ber 3Y TZP, dieser entspricht in der Langzeitsimulation f{\"u}r die Wasserlagerung ca. 35 Jahre. Das wirkt sich insbesondere bei Verschleißpaarungen wie beim k{\"u}nstlichen H{\"u}ftgelenk positiv aus. Verschleißuntersuchungen an einer neu entwickelten Kugel-auf-Scheibe-Geometrie mit li-nearer Kinematik, die dem H{\"u}ftgelenk nachempfunden wurde, belegen die vorteilhaften Verschleißeigenschaften von ATZ in Form von sehr geringen Abtragsraten und einer intak-ten Oberfl{\"a}che nach 720 000 absolvierten Zyklen. Dabei wurde sogar eine Aufh{\"a}rtung der Oberfl{\"a}che durch die Verschleißbeanspruchung um bis zu 8 \% nachgewiesen. Bei der tiefengemittelten Charakterisierung der hydrothermalen Alterung wurde in beiden Materialtypen festgestellt, dass die Geschwindigkeit der Phasentransformation neben der Temperatur merklich von der {\"A}nderung der H2O-Stoffmengenkonzentrantion an der Ober-fl{\"a}che der Keramik abh{\"a}ngig ist, was sich mit den unterschiedlichen Aktivierungsenergien f{\"u}r Wasser- bzw. Wasserdampflagerung belegen l{\"a}sst. Die Aktivierungsenergie Ea der hyd-rothermalen Phasentransformation wurde mit Hilfe der ARRHENIUS-Beziehung ermittelt und betr{\"a}gt f{\"u}r ATZ bei Wasserdampflagerung 102 kJ/mol und bei Wasserlagerung 92 kJ/mol. F{\"u}r Y-TZP betr{\"a}gt die Aktivierungsenergie 114 kJ/mol bei Wasserdampflagerung und 102 kJ/mol bei Wasserlagerung. Der resultierende pr{\"a}exponentielle Faktor k0 unterscheidet sich f{\"u}r Wasserlagerung und Wasserdampflagerung um eine Gr{\"o}ßenordnung, was auf einen leicht andersartigen thermisch aktivierten Gesamtprozess hinweist. Der Avrami-Exponent n, der einen Hinweis auf den Mechanismus der Keimbildung sowie deren geometrische Ordnung geben kann, zeigte keine signifikante Abh{\"a}ngigkeit von der Temperatur und vom Umgebungsmedium. Er ist dagegen zeitabh{\"a}ngig und f{\"a}llt mit zuneh-mender Alterungszeit, d.h. mit zunehmendem monoklinem Gehalt von ca. 4 auf 0,5 ab, was auf eine abnehmende Keimbildungsrate hindeutet. In Verbindung mit weiteren Untersu-chungen durch unabh{\"a}ngige und zum Teil tiefenaufl{\"o}sende Methoden wie GIXRD, NRA und Knoop-Mikroh{\"a}rte-Messungen l{\"a}sst sich der Alterungsmechanismus, bzw. sein zeitlicher und {\"o}rtlicher Ablauf, durch die drei Stadien A, B und C beschreiben: A 0-5 ma. \% m-ZrO2 Quasi-homogene Keimbildung an bevorzugten Orten wie Kornkan-ten und Kornecken (n≈4), Wassertransport wahrscheinlich via Korngrenzendiffusion, Aufh{\"a}rtung der Oberfl{\"a}che B 5-40 ma. \% m-ZrO2 Keimbildung an den Korngrenzfl{\"a}chen bis zur Keims{\"a}ttigung (n≈2), monokline Randschicht w{\"a}chst zeitlich linear, Wassertransport konvektiv {\"u}ber Mikrorisse, deutlicher H{\"a}rteverlust der Oberfl{\"a}che C ≥ 40 ma. \% m-ZrO2 Wachstum der monoklinen Kristallite von den Korngrenzfl{\"a}chen in die tetragonalen Kristallite unter starker Verzwillingung (n≈0,5), Abnahme der tetragonalen Kristallitgr{\"o}ße, starke Mikrorissbildung, dramatischer R{\"u}ckgang der Oberfl{\"a}chenh{\"a}rte Die Kristallitgr{\"o}ße der monoklinen Phase verbleibt im ATZ {\"u}ber alle drei Abschnitte bei 30 ±5 nm. Ein Anwachsen der Kristallite ist mechanische behindert. Kleinere monokline Kristallite sind im ATZ thermodynamisch instabil. Die Kristallitgr{\"o}ße der tetragonalen Phase f{\"a}llt in den Abschnitten A und B sehr langsam und in C sehr schnell bis auf 25 nm ab. Bei dieser Kristallitgr{\"o}ße ist die tetragonale Phase gegen{\"u}ber der monoklinen Phase thermody-namisch stabil. Diese residualen tetragonalen Kristallite weisen nach vollst{\"a}ndigem Reakti-onsablauf einem Anteil von 7 ma. \% auf. Der S{\"a}ttigungsgehalt der monoklinen Phase betrug in beiden Materialen unabh{\"a}ngig von der Temperatur bzw. dem Umgebungsmedium 75 \% der ZrO2-Phase. In Abschnitt C besitzt die residuale tetragonale Phase eine starke Orientierung. Dadurch wird die geometrische Bedingtheit der hydrothermal induzierten Phasenumwandlung ver-deutlicht. Die monokline Phase ist {\"u}ber den gesamten Alterungsprozess stark nach m(1 1  1) orientiert, was mit einer bevorzugten Umklapprichtung der c-Achse zur freien Oberfl{\"a}che hin verbunden ist. Mit Hilfe der tiefenaufgel{\"o}sten Phasenanalyse konnte die Wachstumsgeschwindigkeit der monoklinen Randschicht von der Oberfl{\"a}che in das Volumen untersucht werden. Die Ge-schwindigkeit des Schichtwachstums ist in Abschnitt B nicht zeit- und tiefenabh{\"a}ngig, son-dern konstant mit ausgepr{\"a}gtem ARRHENIUS-Verhalten (Temperaturabh{\"a}ngigkeit). Die Akti-vierungsenergie der Schichtwachstumsgeschwindigkeit km liegt in der gleichen Gr{\"o}ßenord-nung wie die der Transformationskonstante k. Die Umwandlungszone schreitet also mit konstanter Geschwindigkeit in das Volumen fort und hinterl{\"a}sst ein verzweigtes Mikro- und Nanoriss-System. FESEM-Aufnahmen best{\"a}tigen das Vorhandensein einer por{\"o}sen Randschicht, durch die das Wasser nahezu ungehindert eindringen kann. NRA Untersuchungen deuten in Stadium A auf Korngrenzendiffusion hin und best{\"a}tigen in Stadium B einen konvektiven Transport des Wassers an die Transformationszone. Eine Dif-fusion {\"u}ber Sauerstoffleerstellen im Gitter konnte anhand von Proben aus 8YSZ nicht nach-gewiesen werden. Dagegen kommt es in dem verzweigten Riss- und Porensystem in der gealterten Randschicht zum R{\"u}cktransport des Wassers an die Oberfl{\"a}che, sobald die Pro-ben aus der hydrothermalen Atmosph{\"a}re genommen, an Luft gelagert oder in die Hochva-kuumkammer der NRA-Messapparatur eingeschleust werden. Mikrostrukturelle Untersuchungen an eigens entwickelten Verschleißpaarungen zeigten nach 720000 Zyklen {\"a}hnliche Oberfl{\"a}cheneigenschaften wie im Alterungsstadium A. Man kann daher davon ausgehen, dass die Stadien B und C aus Stabilit{\"a}tsgr{\"u}nden in der tribolo-gischen Kontaktzone nicht existieren k{\"o}nnen und es dass sich im Falle einer gleichzeitigen, hydrothermalen und tribologischen Beanspruchung um einen station{\"a}ren Alterungs- und Verschleißprozess handelt. Durch quasiplastische Deformation der monoklinen und tetra-gonalen Kristallite wird die Verschleißrate und die Abriebpartikel bei einer hart /hart Paa-rung aus ATZ deutlich minimiert, so dass ATZ f{\"u}r die H{\"u}ftendoprothetik ein durchaus geeig-neten Werkstoff darstellt, der sich auf der Grundlage der in dieser Arbeit gewonnenen Daten {\"u}ber eine Imlantationsdauer von .mehr als 15 Jahre stabil verhalten kann.}, subject = {Dispersionskeramik}, language = {de} } @phdthesis{Schemmann, author = {Schemmann, Christoph}, title = {Optimierung von radialen Verdichterlaufr{\"a}dern unter Ber{\"u}cksichtigung empirischer und analytischer Vorinformationen mittels eines mehrstufigen Sampling Verfahrens}, doi = {10.25643/bauhaus-universitaet.3974}, url = {http://nbn-resolving.de/urn:nbn:de:gbv:wim2-20190910-39748}, school = {Bauhaus-Universit{\"a}t Weimar}, pages = {233}, abstract = {Turbomachinery plays an important role in many cases of energy generation or conversion. Therefore, turbomachinery is a promising approaching point for optimization in order to increase the efficiency of energy use. In recent years, the use of automated optimization strategies in combination with numerical simulation has become increasingly popular in many fields of engineering. The complex interactions between fluid and solid mechanics encountered in turbomachines on the one hand and the high computational expense needed to calculate the performance on the other hand, have, however, prevented a widespread use of these techniques in this field of engineering. The objective of this work was the development of a strategy for efficient metamodel based optimization of centrifugal compressor impellers. In this context, the main focus is the reduction of the required numerical expense. The central idea followed in this research was the incorporation of preliminary information acquired from low-fidelity computation methods and empirical correlations into the sampling process to identify promising regions of the parameter space. This information was then used to concentrate the numerically expensive high-fidelity computations of the fluid dynamic and structure mechanic performance of the impeller in these regions while still maintaining a good coverage of the whole parameter space. The development of the optimization strategy can be divided into three main tasks. Firstly, the available preliminary information had to be researched and rated. This research identified loss models based on one dimensional flow physics and empirical correlations as the best suited method to predict the aerodynamic performance. The loss models were calibrated using available performance data to obtain a high prediction quality. As no sufficiently exact models for the prediction of the mechanical loading of the impellercould be identified, a metamodel based on finite element computations was chosen for this estimation. The second task was the development of a sampling method which concentrates samples in regions of the parameter space where high quality designs are predicted by the preliminary information while maintaining a good overall coverage. As available methods like rejection sampling or Markov-chain Monte-Carlo methods did not meet the requirements in terms of sample distribution and input correlation, a new multi-fidelity sampling method called "Filtered Sampling"has been developed. The last task was the development of an automated computational workflow. This workflow encompasses geometry parametrization, geometry generation, grid generation and computation of the aerodynamic performance and the structure mechanic loading. Special emphasis was put into the development of a geometry parametrization strategy based on fluid mechanic considerations to prevent the generation of physically inexpedient designs. Finally, the optimization strategy, which utilizes the previously developed tools, was successfully employed to carry out three optimization tasks. The efficiency of the method was proven by the first and second testcase where an existing compressor design was optimized by the presented method. The results were comparable to optimizations which did not take preliminary information into account, while the required computational expense cloud be halved. In the third testcase, the method was applied to generate a new impeller design. In contrast to the previous examples, this optimization featuredlargervariationsoftheimpellerdesigns. Therefore, theapplicability of the method to parameter spaces with significantly varying designs could be proven, too.}, subject = {Simulation}, language = {en} } @phdthesis{Salzmann2010, author = {Salzmann, Holger}, title = {Collaboration in Co-located Automotive Applications}, doi = {10.25643/bauhaus-universitaet.1422}, url = {http://nbn-resolving.de/urn:nbn:de:gbv:wim2-20100712-15102}, school = {Bauhaus-Universit{\"a}t Weimar}, year = {2010}, abstract = {Virtual reality systems offer substantial potential in supporting decision processes based purely on computer-based representations and simulations. The automotive industry is a prime application domain for such technology, since almost all product parts are available as three-dimensional models. The consideration of ergonomic aspects during assembly tasks, the evaluation of humanmachine interfaces in the car interior, design decision meetings as well as customer presentations serve as but a few examples, wherein the benefit of virtual reality technology is obvious. All these tasks require the involvement of a group of people with different expertises. However, current stereoscopic display systems only provide correct 3D-images for a single user, while other users see a more or less distorted virtual model. This is a major reason why these systems still face limited acceptance in the automotive industry. They need to be operated by experts, who have an advanced understanding of the particular interaction techniques and are aware of the limitations and shortcomings of virtual reality technology. The central idea of this thesis is to investigate the utility of stereoscopic multi-user systems for various stages of the car development process. Such systems provide multiple users with individual and perspectively correct stereoscopic images, which are key features and serve as the premise for the appropriate support of collaborative group processes. The focus of the research is on questions related to various aspects of collaboration in multi-viewer systems such as verbal communication, deictic reference, embodiments and collaborative interaction techniques. The results of this endeavor provide scientific evidence that multi-viewer systems improve the usability of VR-applications for various automotive scenarios, wherein co-located group discussions are necessary. The thesis identifies and discusses the requirements for these scenarios as well as the limitations of applying multi-viewer technology in this context. A particularly important gesture in real-world group discussions is referencing an object by pointing with the hand and the accuracy which can be expected in VR is made evident. A novel two-user seating buck is introduced for the evaluation of ergonomics in a car interior and the requirements on avatar representations for users sitting in a car are identified. Collaborative assembly tasks require high precision. The novel concept of a two-user prop significantly increases the quality of such a simulation in a virtual environment and allows ergonomists to study the strain on workers during an assembly sequence. These findings contribute toward an increased acceptance of VR-technology for collaborative development meetings in the automotive industry and other domains.}, subject = {Virtuelle Realit{\"a}t}, language = {en} } @article{Rose2004, author = {Rose, Martin}, title = {Modeling of Freeway Traffic}, doi = {10.25643/bauhaus-universitaet.263}, url = {http://nbn-resolving.de/urn:nbn:de:gbv:wim2-20111215-2639}, year = {2004}, abstract = {An integrated modeling of freeway traffic is developed, whose implementation in an uniform computer -aided simulation model facilitate comparative evaluation and systematic coupling of several traffic simulations, traffic controls, traffic measurements and traffic scenarios. The integrated modeling of freeway traffic is a basic mapping of freeway networks, control methods, measurements and different simulations of traffic flow...}, subject = {Verkehrsplanung}, language = {en} } @article{RombergNigglvanTreeck2004, author = {Romberg, Richard and Niggl, Andreas and van Treeck, Christoph}, title = {Structural Analysis based on the Product Model Standard IFC}, doi = {10.25643/bauhaus-universitaet.243}, url = {http://nbn-resolving.de/urn:nbn:de:gbv:wim2-20111215-2433}, year = {2004}, abstract = {In this paper we present a computer aided method supporting co-operation between different project partners, such as architects and engineers, on the basis of strictly three-dimensional models. The center of our software architecture is a product model, described by the Industry Foundation Classes (IFC) of the International Alliance for Interoperability (IAI). From this a geometrical model is extracted and automatically transferred to a computational model serving as a basis for various simulation tasks. In this paper the focus is set on the advantage of the fully three-dimensional structural analysis performed by p-version of the finite element analysis. Other simulation methods are discussed in a separate contribution of this Volume (Treeck 2004). The validity of this approach will be shown in a complex example.}, subject = {Produktmodell}, language = {en} } @unpublished{RezakazemiMosaviShirazian, author = {Rezakazemi, Mashallah and Mosavi, Amir and Shirazian, Saeed}, title = {ANFIS pattern for molecular membranes separation optimization}, volume = {2018}, doi = {10.25643/BAUHAUS-UNIVERSITAET.3821}, url = {http://nbn-resolving.de/urn:nbn:de:gbv:wim2-20181122-38212}, pages = {1 -- 20}, abstract = {In this work, molecular separation of aqueous-organic was simulated by using combined soft computing-mechanistic approaches. The considered separation system was a microporous membrane contactor for separation of benzoic acid from water by contacting with an organic phase containing extractor molecules. Indeed, extractive separation is carried out using membrane technology where complex of solute-organic is formed at the interface. The main focus was to develop a simulation methodology for prediction of concentration distribution of solute (benzoic acid) in the feed side of the membrane system, as the removal efficiency of the system is determined by concentration distribution of the solute in the feed channel. The pattern of Adaptive Neuro-Fuzzy Inference System (ANFIS) was optimized by finding the optimum membership function, learning percentage, and a number of rules. The ANFIS was trained using the extracted data from the CFD simulation of the membrane system. The comparisons between the predicted concentration distribution by ANFIS and CFD data revealed that the optimized ANFIS pattern can be used as a predictive tool for simulation of the process. The R2 of higher than 0.99 was obtained for the optimized ANFIS model. The main privilege of the developed methodology is its very low computational time for simulation of the system and can be used as a rigorous simulation tool for understanding and design of membrane-based systems. Highlights are, Molecular separation using microporous membranes. Developing hybrid model based on ANFIS-CFD for the separation process, Optimization of ANFIS structure for prediction of separation process}, subject = {Fluid}, language = {en} } @misc{Rauch2008, type = {Master Thesis}, author = {Rauch, Kristin}, title = {Simulation - Termincontrolling beim Bau einer Br{\"u}ckenkappe}, doi = {10.25643/bauhaus-universitaet.1362}, url = {http://nbn-resolving.de/urn:nbn:de:gbv:wim2-20081111-14414}, school = {Bauhaus-Universit{\"a}t Weimar}, year = {2008}, abstract = {Die Simulation ist vor allem in der Forschung und Wissenschaft ein bekanntes Ver-fahren zur Untersuchung von dynamischen Prozessen. Fachgebiete wie u.a. die Medizin und Biologie, das Verkehrswesen, die Automobilindustrie, die Meteorologie und die Fertigungstechnik gewinnen neue Erkenntnisse aus dem Einsatz derartiger Analyseverfahren. Gr{\"u}nde f{\"u}r die Anwendung von Computersimulationen erstrecken sich von finanziellen und zeitlichen Aspekten {\"u}ber eine Risikoverringerung bis hin zu einer vereinfachten Vorgehensweise. Nicht in allen Bereichen aber werden die viel-seitigen Vorteile von Simulationsmethoden genutzt. In der Baubranche wird Simulation derzeit nur ansatzweise eingesetzt. Doch vor al-lem Baustellen bieten durch den zunehmenden Kosten- und Termindruck sowie viel-seitige andere Einfl{\"u}sse eine gute Basis f{\"u}r die Anwendung von Simulationsmetho-den. Der Bauablauf kann dadurch besser kontrolliert und gesteuert werden. In der Planungsphase von Bauprojekten wird Simulation bereits in Grundz{\"u}gen f{\"u}r die Op-timierung von Bauablauf- und Logistikprozessen genutzt. Allerdings ist besonders die Ausf{\"u}hrungsphase durch St{\"o}rungen und {\"A}nderungen gepr{\"a}gt, sodass hier Simu-lationsmethoden noch effektiver eingesetzt werden k{\"o}nnen. Im Rahmen dieser Arbeit sollen die Einsatzm{\"o}glichkeiten von Simulationsmethoden f{\"u}r die Optimierung des Termincontrollings untersucht werden. Durch das Aufzeigen verschiedener Methoden sowie einem Vergleich {\"u}ber ihre Vor- und Nachteile wird herausgefiltert, welches Simulationswerkzeug am effektivsten im Termincontrolling eingesetzt werden kann. Ein weiteres Ziel dieser Arbeit ist die Modellierung eines Beispielprozesses anhand eines ausgew{\"a}hlten Simulationsverfahrens. Die Herstellung einer Br{\"u}ckenkappe wird in diesem Zusammenhang umfangreich dargestellt und analysiert. Eventuelle Zwangspunkte bei der Umsetzung und verschiedene L{\"o}sungsm{\"o}glichkeiten werden aufgezeigt.}, subject = {Simulation}, language = {de} } @misc{Rahm2011, type = {Master Thesis}, author = {Rahm, Tobias}, title = {Simulation von Kernprozessen eines Erddruckschildes}, doi = {10.25643/bauhaus-universitaet.1461}, url = {http://nbn-resolving.de/urn:nbn:de:gbv:wim2-20110909-15599}, school = {Bauhaus-Universit{\"a}t Weimar}, year = {2011}, abstract = {In dieser Arbeit wird der Vortriebsprozess einer Erddruckschildmaschine in einem Simulationsmodell mit Hilfe der System Dynamics modelliert. Nach einer Einf{\"u}hrung in den maschinellen Tunnelbau werden die Besonderheiten der Erddruckschildmaschine herausgestellt. Anschließend wird das betrachtete System mit dem Simulationskonzept der System Dynamics modelliert und in einem geeigneten Simulationstool implementiert.}, subject = {Simulation}, language = {de} } @article{OsadaKoikeMorimoto2004, author = {Osada, Teppei and Koike, Hirotaka and Morimoto, Akinori}, title = {Research on Establishment of a Standard of Traffic Impact Assessment with Integrated Database System}, doi = {10.25643/bauhaus-universitaet.264}, url = {http://nbn-resolving.de/urn:nbn:de:gbv:wim2-20111215-2647}, year = {2004}, abstract = {Planning support systems, such as geographical information system (GIS) and traffic flow simulation models, are widely in use in recent urban planning research. In this paper we propose a method to apply traffic impact assessment (TIA) to large-scale, commercial developments. In TIA research we often encounter the problem of increasing amount of data that is necessary for detailed investigation and analysis, as the scale of commercial developments become larger and more complex. As a result, TIA presents two problems. The first problem is the difficulty of data acquisition. The second problem is the reliability of data. As a solution, we developed an integrated database system.}, subject = {Verkehrsplanung}, language = {en} } @article{NeubergFankEkkerlein2004, author = {Neuberg, Frank and Fank, Ernst and Ekkerlein, Christian}, title = {Integrated Life Cycle Simulation and Assessment of Buildings}, doi = {10.25643/bauhaus-universitaet.235}, url = {http://nbn-resolving.de/urn:nbn:de:gbv:wim2-20111215-2351}, year = {2004}, abstract = {Buildings require both for construction and, due to their comparatively long life cycle for maintenance, significant raw material and energy resources. So far available knowledge about resource consumption during an entire life cycle of a building is still quite rare, because various criteria affect each other and/or overlay mutually. In this contribution a model based software concept is presented using an integrated approach for life cycle simulation and assessment of buildings. The essential point of the development consists of connecting an IFC compliant product model of a building via the Internet with data bases for the resource and energy requirement of building materials. Furthermore, numerical simulations allow calculating and minimizing the energy consumption, the resource requirement, the waste streams and also the noxious emissions. In the context of this paper we present the first release of software programs for architects and engineers, which help them to evaluate their design decisions objectively in early planning steps. Additionally the usage of the software is demonstrated by a test case study for a real world building. By applying this software in practice a substantial contribution for saving energy and natural resources can be provided in the sense of sustainable and ecological building design.}, subject = {Produktmodell}, language = {en} } @article{Makanae2004, author = {Makanae, Koji}, title = {Highway Sequence Editor based on the Length-based Highway Product Model}, doi = {10.25643/bauhaus-universitaet.234}, url = {http://nbn-resolving.de/urn:nbn:de:gbv:wim2-20111215-2347}, year = {2004}, abstract = {The highway product model based on the length information of the centerline, and the application system is developed. This paper shows the schema and the modeling process of the product model, which includes geometric elements such as an alignment, lanes, sidewalks, shoulders and sprits, and accessories such as guard fences, plantings and signs. Furthermore, The Highway Sequence Editor (HSE) is developed as an application system to verify the model.}, subject = {Produktmodell}, language = {en} }