TY - JOUR A1 - Zhang, Yancheng A1 - Wei, Ning A1 - Zhao, Jun-Hua A1 - Gong, Yadong A1 - Rabczuk, Timon T1 - Quasi-analytical solution for the stable system of the multi-layer folded graphene wrinkles JF - Journal of Applied Physics N2 - Quasi-analytical solution for the stable system of the multi-layer folded graphene wrinkles KW - Angewandte Mathematik KW - Strukturmechanik Y1 - 2013 ER - TY - THES A1 - Zhang, Rui T1 - Staatsverständnis und Unternehmensentwicklung am Beispiel chinesischer Buchdruckunternehmen N2 - In der Arbeit wurde eine Methode für eine kulturübergreifende Vergleichsstudie zwischen China und dem Westen erarbeitet. Diese Methode ermöglicht Unternehmensentwicklung in China aus dem eignen historischen Zusammenhang zu verstehen, statt nur aus einem rein theoretischen Blickwinkel. Weil heutige wissenschaftliche Theorien meist aus der westlichen Kultur stammen und mit Wertvorstellungen sowie mit Begriffen aus dem westlichen Kulturkreis verbunden sind, müssen sie im historischen Kontext des westlichen Kulturkreises betrachtet werden. Im ersten Teil der Arbeit wird der westliche moderne Staat als Untersuchungsbegriff herangezogen, seine Entstehungsbedingungen und seine Verwendungsart und -weise, besonders wie er die ökonomische Theorie und die Praxis im Westen beeinflusst, dabei spielt das moderne Staatsprinzip eine wichtige Rolle. Die Neue Institutionenökonomik dient als theoretischer Referenzrahmen für diese Arbeit. Mittels einer theoretischen Erweiterung mit dem westlichen modernen Staatsverständnis werden wichtige westliche konstitutionelle Institutionen analysiert, da sie die Handlungsrechte und -pflichten der Bürger sowie die Bildung der kapitalistischen Unternehmung beeinflussen. Im zweiten Teil der Arbeit wird das chinesische Staatsverständnis analysiert – vom traditionellen „Tianxia“ zum „modernen“ Staat. Mithilfe abgeleiteter Kriterien wird die chinesische Unternehmensentwicklung in drei zeitlichen Querschnittsphasen betrachtet, wie sich chinesische Unternehmen vom traditionellen bis zum „modernen“ entwickelten. Als Fallbeispiel werden chinesische Buchdruckunternehmen herangezogen. Zuerst wird das Buchdrucksystem sowie seine Veränderungen in drei Zeitphase betrachtet. Dabei wird auf die Aspekte Buchdruckorganisation, staatliche Verwaltung, wie Zensur und Urheberrecht sowie Lehrmaterial fokussiert, die für die Buchdruckunternehmensentwicklung von Bedeutung sind und ein System darstellen. Aus Mikrosicht werden drei Buchdruckunternehmen in den Zeitphasen analysiert. Im Ergebnis der Arbeit werden Schlussfolgerungen abgeleitet, bspw. dass Modernisierung als Aktualisierung verstanden werden sollte, aber nicht als Zerstörung. KW - Unternehmen KW - NIÖ KW - Staat KW - China KW - Tradition KW - Moderne KW - Buchdruck KW - Wirtschaft KW - Kulturkreis Y1 - 2016 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:gbv:wim2-20161205-27215 ER - TY - JOUR A1 - Zhang, Chao A1 - Wang, Cuixia A1 - Lahmer, Tom A1 - He, Pengfei A1 - Rabczuk, Timon T1 - A dynamic XFEM formulation for crack identification JF - International Journal of Mechanics and Materials in Design N2 - A dynamic XFEM formulation for crack identification KW - Angewandte Mathematik KW - Stochastik KW - Strukturmechanik Y1 - 2016 SP - 427 EP - 448 ER - TY - JOUR A1 - Zhang, Chao A1 - Nanthakumar, S.S. A1 - Lahmer, Tom A1 - Rabczuk, Timon T1 - Multiple cracks identification for piezoelectric structures JF - International Journal of Fracture N2 - Multiple cracks identification for piezoelectric structures KW - Angewandte Mathematik KW - Stochastik KW - Strukturmechanik Y1 - 2017 SP - 1 EP - 19 ER - TY - JOUR A1 - Zhang, Chao A1 - Hao, Xiao-Li A1 - Wang, Cuixia A1 - Wei, Ning A1 - Rabczuk, Timon T1 - Thermal conductivity of graphene nanoribbons under shear deformation: A molecular dynamics simulation JF - Scientific Reports N2 - Tensile strain and compress strain can greatly affect the thermal conductivity of graphene nanoribbons (GNRs). However, the effect of GNRs under shear strain, which is also one of the main strain effect, has not been studied systematically yet. In this work, we employ reverse nonequilibrium molecular dynamics (RNEMD) to the systematical study of the thermal conductivity of GNRs (with model size of 4 nm × 15 nm) under the shear strain. Our studies show that the thermal conductivity of GNRs is not sensitive to the shear strain, and the thermal conductivity decreases only 12–16% before the pristine structure is broken. Furthermore, the phonon frequency and the change of the micro-structure of GNRs, such as band angel and bond length, are analyzed to explore the tendency of thermal conductivity. The results show that the main influence of shear strain is on the in-plane phonon density of states (PDOS), whose G band (higher frequency peaks) moved to the low frequency, thus the thermal conductivity is decreased. The unique thermal properties of GNRs under shear strains suggest their great potentials for graphene nanodevices and great potentials in the thermal managements and thermoelectric applications. KW - Wärmeleitfähigkeit KW - Graphen KW - Schubspannung Y1 - 2017 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:gbv:wim2-20170428-31718 ER - TY - THES A1 - ZHANG, CHAO T1 - Crack Identification using Dynamic Extended Finite Element Method and Thermal Conductivity Engineering for Nanomaterials N2 - Identification of flaws in structures is a critical element in the management of maintenance and quality assurance processes in engineering. Nondestructive testing (NDT) techniques based on a wide range of physical principles have been developed and are used in common practice for structural health monitoring. However, basic NDT techniques are usually limited in their ability to provide the accurate information on locations, dimensions and shapes of flaws. One alternative to extract additional information from the results of NDT is to append it with a computational model that provides detailed analysis of the physical process involved and enables the accurate identification of the flaw parameters. The aim here is to develop the strategies to uniquely identify cracks in two-dimensional 2D) structures under dynamic loadings. A local NDT technique combined eXtended Finite Element Method (XFEM) with dynamic loading in order to identify the cracks in the structures quickly and accurately is developed in this dissertation. The Newmark-b time integration method with Rayleigh damping is used for the time integration. We apply Nelder-Mead (NM)and Quasi-Newton (QN) methods for identifying the crack tip in plate. The inverse problem is solved iteratively, in which XFEM is used for solving the forward problem in each iteration. For a timeharmonic excitation with a single frequency and a short-duration signal measured along part of the external boundary, the crack is detected through the solution of an inverse time-dependent problem. Compared to the static load, we show that the dynamic loads are more effective for crack detection problems. Moreover, we tested different dynamic loads and find that NM method works more efficient under the harmonic load than the pounding load while the QN method achieves almost the same results for both load types. A global strategy, Multilevel Coordinate Search (MCS) with XFEM (XFEM-MCS) methodology under the dynamic electric load, to detect multiple cracks in 2D piezoelectric plates is proposed in this dissertation. The Newmark-b method is employed for the time integration and in each iteration the forward problem is solved by XFEM for various cracks. The objective functional is minimized by using a global search algorithm MCS. The test problems show that the XFEM-MCS algorithm under the dynamic electric load can be effectively employed for multiple cracks detection in piezoelectric materials, and it proves to be robust in identifying defects in piezoelectric structures. Fiber-reinforced composites (FRCs) are extensively applied in practical engineering since they have high stiffness and strength. Experiments reveal a so-called interphase zone, i.e. the space between the outside interface of the fiber and the inside interface of the matrix. The interphase strength between the fiber and the matrix strongly affects the mechanical properties as a result of the large ratio of interface/volume. For the purpose of understanding the mechanical properties of FRCs with functionally graded interphase (FGI), a closed-form expression of the interface strength between a fiber and a matrix is obtained in this dissertation using a continuum modeling approach according to the ver derWaals (vdW) forces. Based on the interatomic potential, we develop a new modified nonlinear cohesive law, which is applied to study the interface delamination of FRCs with FGI under different loadings. The analytical solutions show that the delamination behavior strongly depends on the interphase thickness, the fiber radius, the Young’s moduli and Poisson’s ratios of the fiber and the matrix. Thermal conductivity is the property of a material to conduct heat. With the development and deep research of 2D materials, especially graphene and molybdenum disulfide (MoS2), the thermal conductivity of 2D materials attracts wide attentions. The thermal conductivity of graphene nanoribbons (GNRs) is found to appear a tendency of decreasing under tensile strain by classical molecular dynamics (MD) simulations. Hence, the strain effects of graphene can play a key role in the continuous tunability and applicability of its thermal conductivity property at nanoscale, and the dissipation of thermal conductivity is an obstacle for the applications of thermal management. Up to now, the thermal conductivity of graphene under shear deformation has not been investigated yet. From a practical point of view, good thermal managements of GNRs have significantly potential applications of future GNR-based thermal nanodevices, which can greatly improve performances of the nanosized devices due to heat dissipations. Meanwhile, graphene is a thin membrane structure, it is also important to understand the wrinkling behavior under shear deformation. MoS2 exists in the stable semiconducting 1H phase (1H-MoS2) while the metallic 1T phase (1T-MoS2) is unstable at ambient conditions. As it’s well known that much attention has been focused on studying the nonlinear optical properties of the 1H-MoS2. In a very recent research, the 1T-type monolayer crystals of TMDCs, MX2 (MoS2, WS2 ...) was reported having an intrinsic in-plane negative Poisson’s ratio. Luckily, nearly at the same time, unprecedented long-term (>3months) air stability of the 1T-MoS2 can be achieved by using the donor lithium hydride (LiH). Therefore, it’s very important to study the thermal conductivity of 1T-MoS2. The thermal conductivity of graphene under shear strain is systematically studied in this dissertation by MD simulations. The results show that, in contrast to the dramatic decrease of thermal conductivity of graphene under uniaxial tensile, the thermal conductivity of graphene is not sensitive to the shear strain, and the thermal conductivity decreases only 12-16%. The wrinkle evolves when the shear strain is around 5%-10%, but the thermal conductivity barely changes. The thermal conductivities of single-layer 1H-MoS2(1H-SLMoS2) and single-layer 1T-MoS2 (1T-SLMoS2) with different sample sizes, temperatures and strain rates have been studied systematically in this dissertation. We find that the thermal conductivities of 1H-SLMoS2 and 1T-SLMoS2 in both the armchair and the zigzag directions increase with the increasing of the sample length, while the increase of the width of the sample has minor effect on the thermal conductions of these two structures. The thermal conductivity of 1HSLMoS2 is smaller than that of 1T-SLMoS2 under size effect. Furthermore, the temperature effect results show that the thermal conductivities of both 1H-SLMoS2 and 1T-SLMoS2 decrease with the increasing of the temperature. The thermal conductivities of 1HSLMoS2 and 1T-SLMoS2 are nearly the same (difference <6%) in both of the chiral orientations under corresponding temperatures, especially in the armchair direction (difference <2.8%). Moreover, we find that the strain effects on the thermal conductivity of 1HSLMoS2 and 1T-SLMoS2 are different. More specifically, the thermal conductivity decreases with the increasing tensile strain rate for 1T-SLMoS2, while fluctuates with the growth of the strain for 1HSLMoS2. Finally, we find that the thermal conductivity of same sized 1H-SLMoS2 is similar with that of the strained 1H-SLMoS2 structure. T3 - ISM-Bericht // Institut für Strukturmechanik, Bauhaus-Universität Weimar - 2018,6 KW - crack KW - Wärmeleitfähigkeit KW - crack identification KW - thermal conductivity Y1 - 2018 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:gbv:wim2-20190119-38478 ER - TY - JOUR A1 - Zhak, S. V. A1 - Sidorenko, V. S. T1 - Optimized Models of Modes Choice for Displacement of technical Systems Objects N2 - The effectiveness of working processes accomplished by various technological machines to a large extend depends on working quality of supply, transporting and orientating mechanisms which are very often produced as positional hydro-mechanical systems. The choice of their best type and regimes of work requires construction and analysis of models of their optimum steering which are complicated by nonlinearness, multy-criterialness of problem and also by occasional outbreaks of parameters and moments of steering regime changing. It was developed the common structure of such systems allowing within common scheme to vary the complexity degree of PHMS and the methods of inhibitory efforts supplement. For some systems which are complicated in series (from two-measured linear system to nine-measured non-linear) puzzles of the most fast zero-ambit getting are solved and two-criterial problems are analyzed. (T-min-speed, Z(T)- accuracy). There are suggested the computing procedures of optimum PHMS synthesis. The effectiveness of accepted methods of solving is asserted by the analogy of the results of gradually complicated models investigation and by their good analogy with the natural experiment. It was exposed the sense of heuristic methods of improving of approximately optimum steering, their elaboration on the base of theoretical models. The basic methods of optimum PGMS construction were also nominated. KW - Modellierung KW - Optimierung Y1 - 1997 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:gbv:wim2-20111215-5347 ER - TY - JOUR A1 - Zerbst, U. A1 - Vormwald, Michael A1 - Andersch, C. A1 - Mädler, K. A1 - Pfuff, M. T1 - The development of a damage tolerance concept for railway components and its demonstration for a railway axle JF - Engineering Fracture Mechanics N2 - The development of a damage tolerance concept for railway components and its demonstration for a railway axle KW - Angewandte Mathematik KW - Strukturmechanik Y1 - 2005 SP - 209 EP - 239 ER - TY - CHAP A1 - Zentner, Frank T1 - Einsatz internetbasierter Projektplattformen im Bereich der Bauausführung - "Digitales Bautagebuch" N2 - Der Einsatz internetbasierter Projektplattformen in der Bauausführung wurde bisher kaum thematisiert. Die typischen Vorteile des Einsatzes solcher Werkzeuge, wie etwa die Unterstützung kooperativer, geographisch und zeitlich verteilter Prozesse, scheinen für diesen Einsatzbereich nicht so offensichtlich zu sein wie für den Bereich der Gebäudeplanung. Vor dem Hintergrund der anhaltend problematischen Situation der Bauwirtschaft und der Tatsache, dass im Bereich der Bauausführung oftmals die wesentlichen Ursachen für einen unplanmäßigen Ablauf von Bauprojekten oder ein Verfehlen von Kosten-, Termin- oder Qualitätszielen zu finden sind, kommt diesen Anwendungen eine große Bedeutung zu. Im Rahmen eines größeren Forschungsprojektes des BMWi (TK3 GIT Siegen / Projektträger PTJ-BEO) wurde unter dem Arbeitstitel >Digitales Bautagebuch< ein ausführungsorientiertes Modul für eine schon in den Planungsphasen des Projektes eingesetzte Projektplattform entwickelt. Dabei wurde projektbegleitend eine Umgebung implementiert, welche sowohl die Bauleitung bei ihrer täglichen Arbeit unterstützt als auch Entscheidungsträgern und anderen Projektbeteiligten einen schnellen Überblick über den Stand der Arbeiten ermöglicht. Dieser Beitrag setzt sich mit dem Einsatz internetbasierter Projektplattformen im Bereich der Bauausführung auseinander und beschreibt deren Möglichkeiten unter Einbringung der Erfahrungen aus der Anwendung im Bauprojekt TK3 GIT Siegen. KW - Digitalisierung KW - Kooperatives Informationssystem KW - Projektmanagement KW - Internet KW - Kooperatives Arbeiten KW - anforderungsorientierte Projektabwicklung KW - internetbasierte Projektplattform KW - Digitales Bautagebuch Y1 - 2003 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:gbv:wim2-20111215-3822 ER - TY - THES A1 - Zellmann, Hans-Dieter T1 - Metaphosphat – modifizierte Silikatbinder als Basis säurebeständiger Beschichtungsmaterialien T1 - Metaphosphate modified silica-binder for acid resistant coating materials N2 - Mörtel basierend auf erhärtetem Wasserglas als Binder weisen eine ausgesprochen gute Beständigkeit im Kontakt mit stark sauren Medien auf; unzureichend hingegen ist die che-mische Beständigkeit im Kontakt mit alkalischen bis schwachsauren Medien. Ziel der Un-tersuchungen ist eine Verbesserung der Wasserbeständigkeit von Natriumsilikatbindern durch gezielte chemische Modifikation mit verschiedenen Metaphosphaten. Durch eine systematische Charakterisierung der Zusammensetzung und des strukturellen Aufbaus der Binder werden dabei die Ursachen der bindertypischen Eigenschaften aufgeklärt. Eine Modifikation der Natriumsilikatlösung mit Natriumtrimetaphosphat hat eine Erhöhung des Kondensationsgrades und eine verbesserte mechanische Beständigkeit des verfestig-ten Natriumsilikatbinders zur Folge. Durch die reaktive Bindung der Basizität der Natriumsi-likatlösung beim Abbau der Metaphosphatstruktur wird die Wasserbeständigkeit mit Natri-umtrimetaphosphat modifizierter Natriumsilikatmörtel erhöht. Die gute Beständigkeit im Kontakt mit hochkonzentrierter Schwefelsäure bleibt nahezu unverändert erhalten. Eine Modifikation der Natriumsilikatlösung mit Aluminiumtetrametaphosphat führt durch Reaktion beider Komponenten miteinander zur Bildung eines alumosilikatischen Netzwer-kes. Das alumosilikatische Netzwerk des mit Aluminiumtetrametaphosphat modifizierten Natriumsilikatbinders ist auch in einer stark alkalischen Natriumhydroxidlösung beständig. Die gute Beständigkeit des Binders im Kontakt mit hochkonzentrierter Schwefelsäure bleibt trotz des Aluminates im Bindernetzwerk erhalten. N2 - Mortars based on hardened water glass as binding agent present a very good resistance in contact with strongly acid fluids. Insufficient, however, is the chemical resistance in contact with alkaline to weakly acid fluids. Aim of the investigations is an improvement of the water resistance of sodium silicate binders by specific chemical modifications through various metaphosphates. Thereby the causes of the binder specific properties are defined by a systematic characterization of the composition and of the structure of the binders. A modification of the sodium silicate solution by sodium trimetaphosphate produces an in-crease of the condensation degree and an improved mechanical resistance of the solidified sodium silicate binder. The water resistance of sodium silicate mortars modified by sodium trimetaphosphate is increased by the reactive binding of the basicity of the sodium silicate solution during the reduction of the metaphosphate structure. The good resistance in con-tact with highly concentrated sulphuric acid is kept nearly unchanged. A modification of the sodium silicate solution by aluminium tetrametaphosphate produces due to the reaction of both components the formation of an aluminosilicate network. The aluminosilicate network of the sodium silicate binder modified by aluminium tetrameta-phosphate also remains resistant in a strongly alkaline sodium hydroxide solution. The good resistance of the binder in contact with highly concentrated sulphuric acid is main-tained despite the aluminate in the binder network. KW - Wasserglas KW - Mörtel KW - Metaphosphat KW - säurefeste Beschichtungen KW - water-glass KW - metaphosphate KW - motars KW - acid resistant coating material Y1 - 2008 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:gbv:wim2-20081127-14385 ER - TY - CHAP A1 - Zeiser, Andreas A1 - Dahmen, W. A1 - Rohwedder, T. A1 - Schneider, R. ED - Gürlebeck, Klaus ED - Könke, Carsten T1 - ADAPTIVE EIGENVALUE COMPUTATION FOR ELLIPTIC OPERATORS N2 - We present recent developments of adaptive wavelet solvers for elliptic eigenvalue problems. We describe the underlying abstract iteration scheme of the preconditioned perturbed iteration. We apply the iteration to a simple model problem in order to identify the main ideas which a numerical realization of the abstract scheme is based upon. This indicates how these concepts carry over to wavelet discretizations. Finally we present numerical results for the Poisson eigenvalue problem on an L-shaped domain. KW - Angewandte Informatik KW - Angewandte Mathematik KW - Architektur KW - Computerunterstütztes Verfahren KW - Computer Science Models in Engineering; Multiscale and Multiphysical Models; Scientific Computing Y1 - 2010 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:gbv:wim2-20170314-29042 UR - http://euklid.bauing.uni-weimar.de/ikm2009/paper.html SN - 1611-4086 ER - TY - THES A1 - Zeh, Rainer T1 - Die Zugfestigkeit bindiger Böden als Kriterium der Rissgefährdung mineralischer Oberflächenabdichtungen T1 - The tensile strength of cohesive soils as cracking criteria of mineral cover linings N2 - Oberflächenabdichtungen von Deponien sind in ihrer langfristigen Funktion häufig durch eine austrocknungsbedingter Rissbildung der mineralischen Dichtungskomponente gefährdet. Als Ursachen gelten insbesondere das standortspezifische Klima mit den stark schwankenden Randbedingungen (Niederschlag, Temperatur), Pflanzen und Tiere sowie auch ein ungeeigneter Systemaufbau. Durch einen Wasserentzug treten Schrumpfungsprozesse in der mineralischen Dichtung auf welche über negative Dehnungen zu Dehnungsbrüchen und damit zu einer Rissbildung führen. Für die Beanspruchbarkeit eines Dichtungsmaterials bei Wasserentzug sind insbesondere dessen Schrumpfverhalten und dessen Zugfestigkeit von Bedeutung. Beide Eigenschaften wurden durch eigens konzipierte Laborversuche beispielhaft an zwei typischen Dichtungsböden untersucht. Die Ergebnisse zeigen eine große Abhängigkeit von der Wasserspannung sowie von der Bodenstruktur. Für die Zugfestigkeit und dem daraus abgeleiteten Dehnungsmodul gilt z. B. jeweils eine eindeutige Zunahme mit Zunahme der Wasserspannungen. Mit Hilfe der Ergebnisse aus den Laborversuchen sowie numerischen Berechnungen des Was-serhaushaltes und der vorherrschenden Spannungen kann eine erste Rissgefährdungsabschätzung für mineralische Dichtungen in Oberflächenabdichtungen abgeleitet und angewandt werden. Weitere Erläuterungen z. B. zu den Eigenschaften und der Teilsättigung bindiger Böden, analytische Zugfestigkeitsberechnungen oder Empfehlungen zum Entwurf und der Herstellung von Oberflächenabdichtungen ergänzen die Arbeit. N2 - The long-term function of cover lining systems of landfills is endangered by desiccation and cracking of the compacted clay liner. The specific climate at the landfill location with its varying conditions (precipitation, temperature), plants and animals or also an inappropriate cover lining system are the causes of these phenomena. Dewatering and desiccation of compacted clay liners produce negative strains and after that strain rupture or cracking. The shrinkage behaviour and the tensile strength of a cover lining material are very important for its capacity. Both characteristics were examined by self-designed laboratory tests which were conducted on two typical cover lining materials. The results show a strong dependency on the suction and on the soil structure. The tensile strength as well as the derived E-modulus increase with increasing suction for example. A first estimation of cracking risk in compacted clay liners of cover lining systems can be derived and used by the presented laboratory test results, numeric calculations of the water balance and the predominant stresses. Further explanations as e. g. the characteristics and unsaturation of cohesive soils, analytic calculations of the tensile strength or recommendations to the design and the production of cover lining systems complete the thesis. KW - Deponiebau KW - Zugfestigkeit KW - Rissbildung KW - Wasserhaushalt KW - Oberflächenabdichtung KW - Teilsättigung KW - landfill cover lining system KW - tensile strength KW - cracking KW - unsaturation KW - water balance Y1 - 2007 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:gbv:wim2-20070522-8692 ER - TY - CHAP A1 - Zavadskas, Edmundas Kazimieras A1 - Peldschus, Friedel T1 - Mehrkriterielle Entscheidungen im Bauwesen N2 - Die Technische Gediminas Universität Vilnius, Lehrstuhl Technologie der Bauproduktion und die Hochschule für Technik, Wirtschaft und Kultur Leipzig, Lehrbereich Baubetrieb, haben sich seit mehreren Jahren mit den Problemen der mehrkriteriellen Entscheidung im Bauwesen befasst. Auf Grund der unterschiedlichen Herangehensweise werden für numerische Lösungen auch unterschiedliche Methoden benutzt. Das gemeinsame Ziel war immer eine optimale Variantenauswahl für baubetriebliche Produktionsprozesse. Zur Unterstützung der numerischen Lösungen wurde gemeinsam das EDV-Programm LEVI entwickelt, welches heute wahlweise als deutschsprachige oder englischsprachige Version genutzt werden kann. Die Beschreibung der zu lösenden Probleme erfolgt in Form einer Matrix. Diese enthält die Varianten (Zeilen) und die Kriterien (Spalten). Dabei sind die Varianten Ausdruck einer Menge real existierender Situationen für ein Problem. Alle betrachteten Varianten werden durch die gleichen Kriterien bewertet. Da die Kriterien gewöhnlich unterschiedliche Dimensionen besitzen, ist ihre Wirksamkeit nicht direkt miteinander vergleichbar. Eine Ausnahme bildet die Bewertung mit einem Punktsystem. Diese beinhaltet jedoch in hohem Maße subjektive Einflüsse und sollte daher nur in Ausnahmefällen benutzt werden. Um die Schwierigkeiten der unterschiedlichen Dimensionen für die verschiedenen Kriterien zu umgehen, wird das Verhältnis zum jeweiligen Optimalwert gebildet. Damit werden gleichzeitig die Diskrepanzen, die durch die unterschiedlichen Größenordnungen der Optimalwerte entstehen, beseitigt. Für das Verhältnis des Funktionswertes zum Optimalwert existieren unterschiedliche Auffassungen. Es muss an dieser Stelle bemerkt werden, dass mit der Entscheidung über die Art des Verhältnisses zum Optimalwert auch die Lösung beeinflusst werden kann. Untersuchungen über solche Auswirkungen sind noch nicht abgeschlossen, so dass im Augenblick nur vorläufige Ergebnisse genannt werden können. Von den bekannten Transformationsmethoden benutzen die Verfasser die vektorwertige Transformation, die lineare Transformation, die relative Abweichung und eine nichtlineare Transformation. Dadurch erfolgt eine Abbildung auf das Intervall [1 ; 0 ] bzw. [ 1 ; ~ 0 ]. Für die Lösungsmethoden erfolgt eine Unterscheidung in eine einseitige oder zweiseitige Fragestellungen. Während die einseitige Fragestellung auf die Bestimmung einer Rangfolge orientiert, berechnet die zweiseitige Fragestellung ein spieltheoretisches Gleichgewicht als Ausdruck eines rationalen Verhaltens von zwei entgegengesetzten Interessengruppen und Lösungen für Spiele gegen die Natur. In Anlehnung an das statische Gleichgewicht messen die Verfasser dem spieltheoretischen Gleichgewicht für die Dimensionierung baubetrieblicher Produktionsprozesse eine besondere Bedeutung zu. Bisherige Anwendungen konzentrieren sich auf die optimale Auswahl im Wohnungsbau, die Auswahl von Konstruktionsvarianten, die Auswahl von Montagevarianten, den Einsatz von Wärmedämmstoffen u.a. Für die Dimensionierung von Produktionsprozessen mit Serienproduktion wurde eine Lösung mit einer gewichteten Matrix vorgeschlagen. KW - Bauwesen KW - Entscheidung bei mehrfacher Zielsetzung Y1 - 2003 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:gbv:wim2-20111215-3812 ER - TY - JOUR A1 - Zavadskas, Edmundas Kazimieras A1 - Kaklauskas, Arturas A1 - Viteikiene, Milda T1 - Database of Best Practices and Decision Support Web-based System for Construction Innovation N2 - Many construction and facilities management Web sites can be found on the Internet. The interested parties on construction and facilities management Web sites can find databases of best practices, calculators, analyzers, software, expert and decision support systems, neural networks, etc. Technological innovation mainly through changes in the availability of information and communication technology inclusive databases of best practices, calculators, analyzers, software, neural networks, decision support and expert systems that have been provided by a variety of new services developed by the construction and facilities management sectors. Most of all calculators, analyzers, software, decision support and expert systems, neural networks and on-line systems seek to find out how to make the most economic decisions and most of all these decisions are intended only for economic objectives. Alternatives under evaluation have to be evaluated not only from the economic position, but take into consideration qualitative, technical, technological and other characteristics as well. Based on the analysis of the existing calculators, analyzers, information, expert and decision support systems, neural networks and in order to determine most efficient versions of best practices a Decision Support Web-Based System for Construction Innovation (IDSS) was developed by Vilnius Gediminas Technical University. KW - Mehragentensystem KW - Lernendes System KW - Wissensverarbeitung Y1 - 2004 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:gbv:wim2-20111215-2173 ER - TY - JOUR A1 - Zavadskas, Edmundas Kazimieras A1 - Kaklauskas, Arturas T1 - Civil Engineering Decision Support Systems in Lithuania N2 - Civil engineering decision support systems (construction, building life cycle, refurbishment, total quality management, innovation, etc.) created in Lithuania are described in this paper. The above decision support systems comprise of the following constituent parts: data (database and its management system), models (model base and its management system) and a user interface. Presentation of information in databases may be in conceptual (digital, textual, graphical, photographic, video) and quantitative forms. Quantitative information presented involves criteria systems and subsystems, units of measurement, values and initial weight fully defining the variants provided. The databases were developed providing a multiple criteria analysis of alternatives from economical, infrastructure, technical, technological, qualitative, legislative, social and other perspectives. This information is provided in a user-oriented way. Since the analysis of alternatives is usually performed by taking into account economical, infrastructure, technical, technological, qualitative and other factors, a model-base include models which enable a decision maker to carry out a comprehensive analysis of the variants available and make a proper choice. These systems, related questions and practical case study were analysed the paper. KW - Wissensmanagement KW - Bautechnik KW - Entscheidungsunterstützungssystem Y1 - 2004 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:gbv:wim2-20111215-2579 ER - TY - JOUR A1 - Zarzycki, Andrzej T1 - Formal Mutations N2 - Wissenschaftliches Kolloquium vom 19. bis 22. April 2007 in Weimar an der Bauhaus-Universität zum Thema: ‚Die Realität des Imaginären. Architektur und das digitale Bild' T3 - Schriften der Bauhaus-Universität Weimar - 120/28 KW - Architektur KW - Design KW - Raum KW - Bild KW - Digitalisierung KW - Bauhaus-Kolloquium KW - Weimar KW - 2007 Y1 - 2008 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:gbv:wim2-20080814-14016 ER - TY - CHAP A1 - Zarli, Alain A1 - Storer, Graham A1 - Kazi, Abdul Samad (Sami) T1 - Building a Better Future: Major Results from the ICCI Cluster Project N2 - To support research in the building sector and in order to help it move towards a new digital economy, the European Commission under the 5th Framework initiative, especially the IST programme, funded various RTD projects. The opportunity to bring these IST projects together was acknowledged so that stronger links can be created under a clustering umbrella and that, moreover, links of those projects with their RTD environment could be facilitated. This has been the objective of work carried out within the ICCI (IST-2001-33022) Cluster project. This paper introduces the main aims and objectives of the project, and then presents its principal outcomes. In a second part, it synthesises the underlying concepts, technology and tools that will make ICT-based Construction a reality in a near future, and gives recommended actions for the industry, the EC and the Construction ICT R&D in Europe, giving some benefit of this project experience to the three communities. KW - Forschung KW - Europa KW - Informationstechnik KW - Baubetrieb Y1 - 2004 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:gbv:wim2-20111215-1994 ER - TY - CHAP A1 - Zang, Di A1 - Sommer, G. ED - Gürlebeck, Klaus ED - Könke, Carsten T1 - ALGEBRAICALLY EXTENDED 2D IMAGE REPRESENTATION N2 - We present an algebraically extended 2D image representation in this paper. In order to obtain more degrees of freedom, a 2D image is embedded into a certain geometric algebra. Combining methods of differential geometry, tensor algebra, monogenic signal and quadrature filter, the novel 2D image representation can be derived as the monogenic extension of a curvature tensor. The 2D spherical harmonics are employed as basis functions to construct the algebraically extended 2D image representation. From this representation, the monogenic signal and the monogenic curvature signal for modeling intrinsically one and two dimensional (i1D/i2D) structures are obtained as special cases. Local features of amplitude, phase and orientation can be extracted at the same time in this unique framework. Compared with the related work, our approach has the advantage of simultaneous estimation of local phase and orientation. The main contribution is the rotationally invariant phase estimation, which enables phase-based processing in many computer vision tasks. KW - Architektur KW - CAD KW - Computerunterstütztes Verfahren Y1 - 2006 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:gbv:wim2-20170327-30396 UR - http://euklid.bauing.uni-weimar.de/ikm2006/index.php_lang=de&what=papers.html ER - TY - CHAP A1 - Zaneldin, Essam T1 - Investigate the Impact of Different Resource Allocation Strategies on the Design of Building Projects Using Simulation N2 - 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. KW - Baubetrieb KW - Computerunterstütztes Verfahren KW - Simulation KW - Bauvorhaben Y1 - 2004 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:gbv:wim2-20111215-1658 ER - TY - GEN A1 - Zanders, Theresa A1 - Bein, Laura Eleana ED - Calbet i Elias, Laura ED - Vollmer, Lisa ED - Zanders, Theresa T1 - Der anonyme Behandlungsschein – von der Idee zur Umsetzung. Ein Handlungsleitfaden N2 - Der vorliegende Handlungsleitfaden hilft zivilgesellschaftlichen Organisationen und staatlichen Einrichtungen bei der Installation eines anonymen Behandlungs- oder Krankenschein für Menschen ohne Krankenversicherung. Dabei bündelt sich hier der Erfahrungsschatz verschiedener Initiativen aus dem gesamten Bundesgebiet. T3 - KoopWohl - Working Paper - 4 KW - Gesundheitsversorgung KW - Migration KW - Anonymer Krankenschein KW - Anonymer Behandlungsschein KW - public private partnership KW - zivilgesellschaftliches Engagement Y1 - 2022 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:gbv:wim2-20220928-47161 ER - TY - RPRT A1 - Zanders, Theresa T1 - Teilhabe an Gesundheitsversorgung von aufenthaltsrechtlich illegalisierten Menschen in Deutschland N2 - Die Gesundheitsversorgung in Deutschland ist seit den Bismarckschen Sozialreformen ein zunehmend institutionalisierter Teil der staatlichen Daseinsvorsorge im wohlfahrtsstaatlichen Gefüge. Institutionalisiert ist die Gesundheitsversorgung in korporatistischer Logik, das heißt in kooperativen Beziehungen zum privatwirtschaftlichen und zivilgesellschaftlichen Sektor und mit Befugnissen der Selbstverwaltung. Zudem fußt das Gesundheitssystem auf einem Versicherungssystem mit lohnabhängigen Abgaben. Institutionalisiert ist die staatliche Daseinsvorsorge jedoch auch in seinen Ausschlüssen. So werden Menschen ohne Bürgerrechte von vielen sozialen Rechten, wie von der Gesundheitsversorgung, ausgeschlossen, obwohl dieser Ausschluss im Widerspruch zu anderen konstitutiven Elementen des Nationalstaats steht. In diesem Working Paper werden die grundlegende Strukturen des deutschen Gesundheitssystems und darin innewohnende Funktionslogiken der Produktion von Teilhabe dargestellt. Abschließend werden in Anlehnung an Kronauer die verschiedenen Dimensionen von Teilhabe an Gesundheitsversorgung in ihrer Produktions- und Ausschlusslogik im Wohlfahrtsregime dargelegt dabei auf die Gruppe der aufenthaltsrechtlich Illegalisierten fokussiert, denen gesellschaftliche Teilhabe in vielen Lebensbereichen, wie auch stark im Gesundheitsbereich, untersagt wird. Gleichzeitig soll dargestellt werden, wie zivilgesellschaftliche Akteur*innen auch gegen staatliche Vorgaben oder Anreize, Teilhabe (wieder-)herstellen. T3 - KoopWohl - Working Paper - 3 KW - Gesundheit KW - Migration KW - Anonymer Krankenschein Y1 - 2022 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:gbv:wim2-20230530-63968 ER - TY - JOUR A1 - Zander, Steffi A1 - Wetzel, Stefanie A1 - Kühl, Tim A1 - Bertel, Sven T1 - Underlying Processes of an Inverted Personalization Effect in Multimedia Learning – An Eye-Tracking Study JF - Frontiers in Psychology N2 - One of the frequently examined design principles recommendations in multimedia learning is the personalization principle. Based on empirical evidence this principle states that using personalised messages in multimedia learning is more beneficial than using formal language (e.g. using ‘you’ instead of ‘the’). Although there is evidence that these slight changes in regard to the language style affect learning, motivation and the perceived cognitive load, it remains unclear, (1) whether the positive effects of personalised language can be transferred to all kinds of content of learning materials (e.g. specific potentially aversive health issues) and (2) which are the underlying processes (e.g. attention allocation) of the personalization effect. German university students (N= 37) learned symptoms and causes of cerebral haemorrhages either with a formal or a personalised version of the learning material. Analysis revealed comparable results to the few existing previous studies, indicating an inverted personalization effect for potentially aversive learning material. This effect was specifically revealed in regard to decreased average fixation duration and the number of fixations exclusively on the images in the personalised compared to the formal version. This result can be seen as indicators for an inverted effect of personalization on the level of visual attention. KW - Lernen KW - multimedia learning KW - Computerunterstütztes Lernen KW - Multimedia KW - personalization effect KW - eye-tracking KW - cognitive load KW - multimedia design principles KW - OA-Publikationsfonds2017 Y1 - 2017 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:gbv:wim2-20180312-37342 UR - https://www.frontiersin.org/articles/10.3389/fpsyg.2017.02202/full VL - 2017 IS - Volume 8, Article 2202 SP - 1 EP - 16 ER - TY - CHAP A1 - Zahm, Petra T1 - Der Ausschuss für Sicherheit und Gesundheitsschutz auf Baustellen – Praxiserfahrungen bei der Überwachung der Baustellenverordnung aus der Sicht der sächsischen Arbeitsschutzverwaltung N2 - Der Ausschuss für Sicherheit und Gesundheitsschutz auf Baustellen; Praxiserfahrungen bei der Überwachung der Baustellenverordnung aus der Sicht der sächsischen Arbeitsschutzverwaltung KW - Arbeitsschutz KW - Baustelle KW - Deutschland / Baustellenverordnung Y1 - 2003 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:gbv:wim2-20111215-4689 ER - TY - GEN A1 - Zahlten, Andreas T1 - Strategien zur optimalen Baugrunderkundung auf der Basis geostatistischer Baugrundmodelle N2 - Der Baugrund ist durch seine geologische Entstehung und verschiedener anthropogener Einflüsse geprägt. Dadurch ist er in seinen physikalischen und geometrischen Eigenschaften inhomogen. Aufgrund des oftmals geringen Erkundungsumfangs durch wenige punktförmige Aufschlüsse unterliegen die Baugrunddaten einer zufälligen und systematischen räumlichen Streuung. Die Unsicherheit der Messergebnisse ist u.a durch Fehlerquellen in den Messverfahren, in den empirischen Beziehungen zur Bestimmung der Baugrundparameter und bei der Datenbearbeitung sowie in der Heterogenität des Mediums Boden begründet. In der Praxis werden aus den Erkundungsergebnissen des Baugrundes Schichtenverzeichnisse erstellt, in denen Homogenbereiche definiert werden können. Mittels definierter Schichtmächtigkeiten oder festgelegter Schichtgrenzen lässt sich ein dreidimensionales geologisches Schichtenmodell aufbauen, das aus mehreren miteinander verbundenen zweidimensionalen Datensätzen besteht. Für Interpolationen innerhalb eines Untersuchungsraumes im geologischen Modell haben sich geostatistische Methoden als geeignet erwiesen. Die Modellierung des Baugrundes mit Hilfe von geostatistischen Verfahren in der Praxis geschieht bisher in der Regel auf der Annahme deterministischer Eingangsgrößen. Die Untersuchung des Einflusses streuender und unsicherer Ausgangskennwerte auf die Ergebnisse der einzelnen Stufen der geostatistischen Modellbildung erlaubt eine bessere Beurteilung der Berechnungsergebnisse. In der Geotechnik wird deshalb versucht, die Vorteile geostatistischer Verfahren in bodenmechanische Nachweise einzubeziehen. Bodenkenngrößen können damit qualifizierter und mit verbesserter Aussagesicherheit in die Gründungsberechnungen und Nachweise eingehen. Baugrunderkundungen sind ein Kostenfaktor bei der Entwicklung und Durchführung eines Bauprojektes. Der Baugrund kann deswegen unter dem Gesichtspunkt der Wirtschaftlichkeit nur an wenigen Stellen untersucht werden. Großflächige Areale, die z.B. für eine Ansiedlung von Industrie und Gewerbe vorgesehen sind, werden im Rahmen einer Vorerkundung punktuell beprobt. Sind dann innerhalb von Lokalbereichen konkrete Projekte geplant, werden diese Flächen in einer Nacherkundung detailliert und spezifisch untersucht. Ziel dieser Arbeit ist die Entwicklung von Strategien, die es erlauben, unter Einbeziehung von Ergebnissen aus Vorerkundungsuntersuchungen und anderen zusätzlichen Informationsquellen eine optimale Anordnung der Punkte für eine Nacherkundung eines Lokalbereiches mit möglichst geringen zusätzlichen Kosten zu finden. Mit Hilfe einer optimierten Messnetzkonstellation und einer verbesserten Aussagekraft der Messwerte soll die Aussagesicherheit der räumlichen Schätzung der Baugrundkenngrößen an unbeprobten Orten verbessert und gesteigert werden. Hierzu gilt es die Unsicherheiten aus dem Messnetz und aus den Baugrundkenngrößen zu analysieren, miteinander zu verknüpfen und Strategien zur Reduktion der Unsicherheiten zu entwickeln. KW - Baugrund KW - Kriging KW - Messstellennetz KW - Geometrische Optimierung KW - Messnetzplanung KW - Messnetzoptimierung KW - Optimierung Krigingvarianz KW - Optimierung Kenngrößenvarianz KW - Unsicherheitplot Y1 - 2005 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:gbv:wim2-20111215-7283 ER - TY - THES A1 - Zafar, Usman T1 - Probabilistic Reliability Analysis of Wind Turbines N2 - Renewable energy use is on the rise and these alternative resources of energy can help combat with the climate change. Around 80% of the world's electricity comes from coal and petroleum however, the renewables are the fastest growing source of energy in the world. Solar, wind, hydro, geothermal and biogas are the most common forms of renewable energy. Among them, wind energy is emerging as a reliable and large-scaled source of power production. The recent research and confidence in the performance has led to the construction of more and bigger wind turbines around the world. As wind turbines are getting bigger, a concern regarding their safety is also in discussion. Wind turbines are expensive machinery to construct and the enormous capital investment is one of the main reasons, why many countries are unable to adopt to the wind energy. Generally, a reliable wind turbine will result in better performance and assist in minimizing the cost of operation. If a wind turbine fails, it's a loss of investment and can be harmful for the surrounding habitat. This thesis aims towards estimating the reliability of an offshore wind turbine. A model of Jacket type offshore wind turbine is prepared by using finite element software package ABAQUS and is compared with the structural failure criteria of the wind turbine tower. UQLab, which is a general uncertainty quantification framework developed at ETH Zürich, is used for the reliability analysis. Several probabilistic methods are included in the framework of UQLab, which include Monte Carlo, First Order Reliability Analysis and Adaptive Kriging Monte Carlo simulation. This reliability study is performed only for the structural failure of the wind turbine but it can be extended to many other forms of failures e.g. reliability for power production, or reliability for different component failures etc. It's a useful tool that can be utilized to estimate the reliability of future wind turbines, that could result in more safer and better performance of wind turbines. KW - Windturbine KW - Windenergie KW - Wind Turbines KW - Wind Energy KW - Reliability Analysis KW - Zuverlässigkeitsanalyse Y1 - 2019 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:gbv:wim2-20240507-39773 ER - TY - THES A1 - Zacharias, Christin T1 - Numerical Simulation Models for Thermoelastic Damping Effects N2 - Finite Element Simulations of dynamically excited structures are mainly influenced by the mass, stiffness, and damping properties of the system, as well as external loads. The prediction quality of dynamic simulations of vibration-sensitive components depends significantly on the use of appropriate damping models. Damping phenomena have a decisive influence on the vibration amplitude and the frequencies of the vibrating structure. However, developing realistic damping models is challenging due to the multiple sources that cause energy dissipation, such as material damping, different types of friction, or various interactions with the environment. This thesis focuses on thermoelastic damping, which is the main cause of material damping in homogeneous materials. The effect is caused by temperature changes due to mechanical strains. In vibrating structures, temperature gradients arise in adjacent tension and compression areas. Depending on the vibration frequency, they result in heat flows, leading to increased entropy and the irreversible transformation of mechanical energy into thermal energy. The central objective of this thesis is the development of efficient simulation methods to incorporate thermoelastic damping in finite element analyses based on modal superposition. The thermoelastic loss factor is derived from the structure's mechanical mode shapes and eigenfrequencies. In subsequent analyses that are performed in the time and frequency domain, it is applied as modal damping. Two approaches are developed to determine the thermoelastic loss in thin-walled plate structures, as well as three-dimensional solid structures. The realistic representation of the dissipation effects is verified by comparing the simulation results with experimentally determined data. Therefore, an experimental setup is developed to measure material damping, excluding other sources of energy dissipation. The three-dimensional solid approach is based on the determination of the generated entropy and therefore the generated heat per vibration cycle, which is a measure for thermoelastic loss in relation to the total strain energy. For thin plate structures, the amount of bending energy in a modal deformation is calculated and summarized in the so-called Modal Bending Factor (MBF). The highest amount of thermoelastic loss occurs in the state of pure bending. Therefore, the MBF enables a quantitative classification of the mode shapes concerning the thermoelastic damping potential. The results of the developed simulations are in good agreement with the experimental results and are appropriate to predict thermoelastic loss factors. Both approaches are based on modal superposition with the advantage of a high computational efficiency. Overall, the modeling of thermoelastic damping represents an important component in a comprehensive damping model, which is necessary to perform realistic simulations of vibration processes. N2 - Die Finite-Elemente Simulation von dynamisch angeregten Strukturen wird im Wesentlich durch die Steifigkeits-, Massen- und Dämpfungseigenschaften des Systems sowie durch die äußere Belastung bestimmt. Die Vorhersagequalität von dynamischen Simulationen schwingungsanfälliger Bauteile hängt wesentlich von der Verwendung geeigneter Dämpfungsmodelle ab. Dämpfungsphänomene haben einen wesentlichen Einfluss auf die Schwingungsamplitude, die Frequenz und teilweise sogar die Existenz von Vibrationen. Allerdings ist die Entwicklung von realitätsnahen Dämpfungsmodellen oft schwierig, da eine Vielzahl von physikalischen Effekten zur Energiedissipation während eines Schwingungsvorgangs führt. Beispiele hierfür sind die Materialdämpfung, verschiedene Formen der Reibung sowie vielfältige Wechselwirkungen mit dem umgebenden Medium. Diese Dissertation befasst sich mit thermoelastischer Dämpfung, die in homogenen Materialien die dominante Ursache der Materialdämpfung darstellt. Der thermoelastische Effekt wird ausgelöst durch eine Temperaturänderung aufgrund mechanischer Spannungen. In der schwingenden Struktur entstehen während der Deformation Temperaturgradienten zwischen benachbarten Regionen unter Zug- und Druckbelastung. In Abhängigkeit von der Vibrationsfrequenz führen diese zu Wärmeströmen und irreversibler Umwandlung mechanischer in thermische Energie. Die Zielstellung dieser Arbeit besteht in der Entwicklung recheneffizienter Simulationsmethoden, um thermoelastische Dämpfung in zeitabhängigen Finite-Elemente Analysen, die auf modaler Superposition beruhen, zu integrieren. Der thermoelastische Verlustfaktor wird auf der Grundlage der mechanischen Eigenformen und -frequenzen bestimmt. In nachfolgenden Analysen im Zeit- und Frequenzbereich wird er als modaler Dämpfungsgrad verwendet. Zwei Ansätze werden entwickelt, um den thermoelastischen Verlustfaktor in dünn-wandigen Plattenstrukturen, sowie in dreidimensionalen Volumenbauteilen zu simulieren. Die realitätsnahe Vorhersage der Energiedissipation wird durch die Verifizierung an experimentellen Daten bestätigt. Dafür wird ein Versuchsaufbau entwickelt, der eine Messung von Materialdämpfung unter Ausschluss anderer Dissipationsquellen ermöglicht. Für den Fall der Volumenbauteile wird ein Ansatz verwendet, der auf der Berechnung der Entropieänderung und damit der erzeugte Wärmeenergie während eines Schwingungszyklus beruht. Im Verhältnis zur Formänderungsenergie ist dies ein Maß für die thermoelastische Dämpfung. Für dünne Plattenstrukturen wird der Anteil an Biegeenergie in der Eigenform bestimmt und im sogenannten modalen Biegefaktor (MBF) zusammengefasst. Der maximale Grad an thermoelastischer Dämpfung kann im Zustand reiner Biegung auftreten, sodass der MBF eine quantitative Klassifikation der Eigenformen hinsichtlich ihres thermoelastischen Dämpfungspotentials zulässt. Die Ergebnisse der entwickelten Simulationsmethoden stimmen sehr gut mit den experimentellen Daten überein und sind geeignet, um thermoelastische Dämpfungsgrade vorherzusagen. Beide Ansätze basieren auf modaler Superposition und ermöglichen damit zeitabhängige Simulationen mit einer hohen Recheneffizienz. Insgesamt stellt die Modellierung der thermoelastischen Dämpfung einen Baustein in einem umfassenden Dämpfungsmodell dar, welches zur realitätsnahen Simulation von Schwingungsvorgängen notwendig ist. T3 - ISM-Bericht // Institut für Strukturmechanik, Bauhaus-Universität Weimar - 2022,8 KW - Werkstoffdämpfung KW - Finite-Elemente-Methode KW - Strukturdynamik KW - Thermoelastic damping KW - modal damping KW - decay experiments KW - energy dissipation Y1 - 2022 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:gbv:wim2-20221116-47352 ER - TY - JOUR A1 - Zabel, Volkmar A1 - Brehm, Maik T1 - Das dynamische Verhalten von Eisenbahnbrücken mit kurzer Spannweite - numerische und experimentelle Untersuchungen JF - Bauingenieur, D-A-CH-Mitteilungsblatt N2 - Das dynamische Verhalten von Eisenbahnbrücken mit kurzer Spannweite - numerische und experimentelle Untersuchungen KW - Angewandte Mathematik KW - Strukturmechanik Y1 - 2008 ER - TY - THES A1 - Zabel, Volkmar T1 - Anwendungen der Wavelet-Transformation in der Systemidentifikation T1 - Applications of Wavelet Analysis in System Identification N2 - Die meisten traditionellen Methoden der Systemidentifikation beruhen auf der Abbildung der Meßwerte entweder im Zeit- oder im Frequenzbereich. In jüngerer Zeit wurden im Zusammenhang mit der Systemidentifikation Verfahren entwicklet, die auf der Anwendung der Wavelet-Transformation beruhen. Das Ziel dieser Arbeit war, einen Algorithmus zu entwickeln, der die Identifikation von Parametern eines Finite-Elemente-Modells, das ein experimentell untersuchtes mechanisches System beschreibt, ermöglicht. Es wurde eine Methode erarbeitet, mit deren Hilfe die gesuchten Parameter durch Lösen eines Systems von Bewegungsgleichungen im Zeit-Skalen-Bereich ermittelt werden. Durch die Anwendung dieser Darstellung können Probleme, die durch Rauschanteile in den Meßdaten entstehen, reduziert werden. Die Ergebnisse numerischer Simulation und einer experimentellen Studie bestätigen die Vorteile einer Anwendung der Wavelet-Transformation in der vorgeschlagenen Weise. ... N2 - Most traditional methods in system identification are based on the analysis of measured data in either the time or frequency domain. In recent years some procedures were developed that apply wavelet analysis in the context of system identification. The purpose of this study was to develop an algorithm that allows for identifying the parameters of a finite element model that describes a tested mechanical system. A method has been derived that determines the desired parameters by solving a system of equations of motion in the time-scale domain. ... KW - Wavelet KW - Systemidentifikation KW - Verbindungskoeffizienten KW - Schädigungsindikator KW - Dynamik KW - Strukturdynamik KW - wavelet KW - system identification KW - connection coefficients KW - damage indicator KW - dynamics Y1 - 2003 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:gbv:wim2-20040202-66 ER - TY - JOUR A1 - Zabel, Volkmar T1 - An application of discrete wavelet analysis and connection coefficients to parametric system identification JF - Structural Health Monitoring N2 - An application of discrete wavelet analysis and connection coefficients to parametric system identification KW - Angewandte Mathematik KW - Strukturmechanik Y1 - 2005 SP - 5 EP - 18 ER - TY - THES A1 - Zabel, Volkmar ED - Könke, Carsten ED - Lahmer, Tom ED - Rabczuk, Timon T1 - Operational modal analysis - Theory and aspects of application in civil engineering N2 - In recent years the demand on dynamic analyses of existing structures in civil engineering has remarkably increased. These analyses are mainly based on numerical models. Accordingly, the generated results depend on the quality of the used models. Therefore it is very important that the models describe the considered systems such that the behaviour of the physical structure is realistically represented. As any model is based on assumptions, there is always a certain degree of uncertainty present in the results of a simulation based on the respective numerical model. To minimise these uncertainties in the prediction of the response of a structure to a certain loading, it has become common practice to update or calibrate the parameters of a numerical model based on observations of the structural behaviour of the respective existing system. The determination of the behaviour of an existing structure requires experimental investigations. If the numerical analyses concern the dynamic response of a structure it is sensible to direct the experimental investigations towards the identification of the dynamic structural behaviour which is determined by the modal parameters of the system. In consequence, several methods for the experimental identification of modal parameters have been developed since the 1980ies. Due to various technical restraints in civil engineering which limit the possibilities to excitate a structure with economically reasonable effort, several methods have been developed that allow a modal identification form tests with an ambient excitation. The approach of identifying modal parameters only from measurements of the structural response without precise knowledge of the excitation is known as output-only or operational modal analysis. Since operational modal analysis (OMA) can be considered as a link between numerical modelling and simulation on the one hand and the dynamic behaviour of an existing structure on the other hand, the respective algorithms connect both the concepts of structural dynamics and mathematical tools applied within the processing of experimental data. Accordingly, the related theoretical topics are revised after an introduction into the topic. Several OMA methods have been developed over the last decades. The most established algorithms are presented here and their application is illustrated by means of both a small numerical and an experimental example. Since experimentally obtained results always underly manifold influences, an appropriate postprocessing of the results is necessary for a respective quality assessment. This quality assessment does not only require respective indicators but should also include the quantification of uncertainties. One special feature in modal testing is that it is common to instrument the structure in different sensor setups to improve the spacial resolution of identified mode shapes. The modal information identified from tests in several setups needs to be merged a posteriori. Algorithms to cope with this problem are also presented. Due to the fact that the amount of data generated in modal tests can become very large, manual processing can become extremely expensive or even impossible, for example in the case of a long-term continuous structural monitoring. In these situations an automated analysis and postprocessing are essential. Descriptions of respective methodologies are therefore also included in this work. Every structural system in civil engineering is unique and so also every identification of modal parameters has its specific challenges. Some aspects that can be faced in practical applications of operational modal analysis are presented and discussed in a chapter that is dedicated specific problems that an analyst may have to overcome. Case studies of systems with very close modes, with limited accessibility as well as the application of different OMA methods are described and discussed. In this context the focus is put on several types of uncertainty that may occur in the multiple stages of an operational modal analysis. In literature only very specific uncertainties at certain stages of the analysis are addressed. Here, the topic of uncertainties has been considered in a broader sense and approaches for treating respective problems are suggested. Eventually, it is concluded that the methodologies of operatinal modal analysis and related technical solutions have been well-engineered already. However, as in any discipline that includes experiments, a certain degree of uncertainty always remains in the results. From these conclusions has been derived a demand for further research and development that should be directed towards the minimisation of these uncertainties and to a respective optimisation of the steps and corresponding parameters included in an operational modal analysis. T3 - ISM-Bericht // Institut für Strukturmechanik, Bauhaus-Universität Weimar - 2019,5 KW - Modalanalyse KW - Strukturdynamik KW - Operational modal analysis KW - modal analysis KW - structural dynamics Y1 - 2019 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:gbv:wim2-20191030-40061 ER - TY - THES A1 - Yuli, Nensi Golda T1 - The Spatial Concept at Moslem Settlements in Current Context of Modern Indonesia Using Phenomenology Method . Case Study: Pathok Negoro Area in Yogyakarta, Indonesia N2 - Settlement is human place to live and do various activities (Finch, 1980). Concept of settlement layout is closely associated with human and a set of thoughts and behaviors. In this case, idea of pattern of activities in a society that is core of a culture becomes main factor in process of formation of houses and environment in a settlement. Factors which affecting form (physical) of architecture in a settlement environment are socio-cultural, economic, and religious determinant factor that manifested architectural realization (Rapoport, 1969). Yogyakarta as the continuation of kingdom city in the Java Island finally exists as an Islamic kingdom that still remain to survive up to now. Impacts of this issue is appearance of various Moslem settlements to support typical character of an Islamic Kingdom. Mlangi is an area of oldest Moslem settlements in Yogyakarta has not been explored in details for progress especially in physical glasses recently. Everything basic group and individual who arrange houses and residences, starts from how it has spatial concept alone. Although concept is a very abstract thing to explain in details, but its existence can be detected by how they created their physical environment. This research conducted by these research questions: (1) What are spatial concepts owned by people in Mlangi and (2) How do spatial concepts owned by the people affect the settlements pattern? Process to search spatial concept owned by the people in Moslem residence, making Mlangi as study area, was approached by using phenomenological research method. The researcher have to self-involved directly in unstructured interviews, but remained in guideline framework of in interviews to make research process effective. Fistly, the researcher interviewed the key person, they are the head of Mlangi administration (pak Dukuh) in Mlangi and Sawahan. They were then give advices to who was capable person that could draw the spatial concept and had many story and knew the history of the settlements. Step by step of interview guided from one informant to next informant when the information had been told repeatedly. The next informant based on the last informant advice or who had close relationship with the last theme appeared. To complete the narration and draw the result of interview, researcher have to add additional information with photograph and descriptive picture that can be draw the settlement empirically. In process, 17 information units which found in field were consistent with sequence of interview events and flowing of theme to theme associated with Moslem residence of residence. Finally the interviews succeeded in abstracting 16 themes that may be classified into historic, socio-cultural, and spatial-concept dimensions in Mlangi. Process of analysis to find spatial concept owned by the people in Moslem settlements was carried out by dialogue of themes to find available substantive relationship. Four concepts successfully analyzed consist of concepts of personage, concept of religious implementation, concept of Jero-Jaba and concept of Interest. The four concepts are really associated with one and others in understanding how spatial concept owned by the people affects residence they occupy. Yet, concept of Jero-Jaba bases all concepts of people in Mlangi . This concept can be used to draw red yarn on how they utilize communal spaces in residence and layout rooms of their individual houses. This concept also eternalize residence patterns existing in Mlangi now where residence does not experience many changes from starting of this residence existence (from detection of generation currently still living), namely residence patterns concentrate on orientation to Masjid Pathok Negoro of Mlangi. This research was opening the potential research area, at least for the sociology, anthropology and demography research interest. So many unique character in Mlangi if looked at from how they maintain their spatial concept and manifested in their daily activities. How the people will concern only for the religious activities and the economic concern only for survival aspect in live. Keywords: spatial concept, moslem settlements, phenomenology method, Indonesia, KW - Siedlung KW - spatial concept KW - Muslim KW - moslem settlements KW - phenomenology method KW - Indonesia Y1 - 2017 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:gbv:wim2-20170419-31257 ER - TY - THES A1 - Yousefi, Hassan T1 - Discontinuous propagating fronts: linear and nonlinear systems N2 - The aim of this study is controlling of spurious oscillations developing around discontinuous solutions of both linear and non-linear wave equations or hyperbolic partial differential equations (PDEs). The equations include both first-order and second-order (wave) hyperbolic systems. In these systems even smooth initial conditions, or smoothly varying source (load) terms could lead to discontinuous propagating solutions (fronts). For the first order hyperbolic PDEs, the concept of central high resolution schemes is integrated with the multiresolution-based adaptation to capture properly both discontinuous propagating fronts and effects of fine-scale responses on those of larger scales in the multiscale manner. This integration leads to using central high resolution schemes on non-uniform grids; however, such simulation is unstable, as the central schemes are originally developed to work properly on uniform cells/grids. Hence, the main concern is stable collaboration of central schemes and multiresoltion-based cell adapters. Regarding central schemes, the considered approaches are: 1) Second order central and central-upwind schemes; 2) Third order central schemes; 3) Third and fourth order central weighted non-oscillatory schemes (central-WENO or CWENO); 4) Piece-wise parabolic methods (PPMs) obtained with two different local stencils. For these methods, corresponding (nonlinear) stability conditions are studied and modified, as well. Based on these stability conditions several limiters are modified/developed as follows: 1) Several second-order limiters with total variation diminishing (TVD) feature, 2) Second-order uniformly high order accurate non-oscillatory (UNO) limiters, 3) Two third-order nonlinear scaling limiters, 4) Two new limiters for PPMs. Numerical results show that adaptive solvers lead to cost-effective computations (e.g., in some 1-D problems, number of adapted grid points are less than 200 points during simulations, while in the uniform-grid case, to have the same accuracy, using of 2049 points is essential). Also, in some cases, it is confirmed that fine scale responses have considerable effects on higher scales. In numerical simulation of nonlinear first order hyperbolic systems, the two main concerns are: convergence and uniqueness. The former is important due to developing of the spurious oscillations, the numerical dispersion and the numerical dissipation. Convergence in a numerical solution does not guarantee that it is the physical/real one (the uniqueness feature). Indeed, a nonlinear systems can converge to several numerical results (which mathematically all of them are true). In this work, the convergence and uniqueness are directly studied on non-uniform grids/cells by the concepts of local numerical truncation error and numerical entropy production, respectively. Also, both of these concepts have been used for cell/grid adaptations. So, the performance of these concepts is also compared by the multiresolution-based method. Several 1-D and 2-D numerical examples are examined to confirm the efficiency of the adaptive solver. Examples involve problems with convex and non-convex fluxes. In the latter case, due to developing of complex waves, proper capturing of real answers needs more attention. For this purpose, using of method-adaptation seems to be essential (in parallel to the cell/grid adaptation). This new type of adaptation is also performed in the framework of the multiresolution analysis. Regarding second order hyperbolic PDEs (mechanical waves), the regularization concept is used to cure artificial (numerical) oscillation effects, especially for high-gradient or discontinuous solutions. There, oscillations are removed by the regularization concept acting as a post-processor. Simulations will be performed directly on the second-order form of wave equations. It should be mentioned that it is possible to rewrite second order wave equations as a system of first-order waves, and then simulated the new system by high resolution schemes. However, this approach ends to increasing of variable numbers (especially for 3D problems). The numerical discretization is performed by the compact finite difference (FD) formulation with desire feature; e.g., methods with spectral-like or optimized-error properties. These FD methods are developed to handle high frequency waves (such as waves near earthquake sources). The performance of several regularization approaches is studied (both theoretically and numerically); at last, a proper regularization approach controlling the Gibbs phenomenon is recommended. At the end, some numerical results are provided to confirm efficiency of numerical solvers enhanced by the regularization concept. In this part, shock-like responses due to local and abrupt changing of physical properties, and also stress wave propagation in stochastic-like domains are studied. KW - Partielle Differentialgleichung KW - Adaptives System KW - Wavelet KW - Tichonov-Regularisierung KW - Hyperbolic PDEs KW - Adaptive central high resolution schemes KW - Wavelet based adaptation KW - Tikhonov regularization Y1 - 2022 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:gbv:wim2-20220922-47178 ER - TY - CHAP A1 - Yatsuka, Hajime T1 - Global standard? N2 - Wissenschaftliches Kolloquium vom 14. bis 16. Oktober 1999 in Weimar an der Bauhaus-Universität zum Thema: ‚global village - Perspektiven der Architektur' T3 - Thesis // Bauhaus-Universität - 46.2000,4-5/131-134 KW - Architektur KW - Landschaftsgebundenes Bauen KW - Globalisierung KW - Bauhaus-Kolloquium KW - Weimar KW - 1999 Y1 - 2000 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:gbv:wim2-20111215-12071 ER - TY - CHAP A1 - Yansong, Ma ED - Faschingeder, Kristian ED - Jormakka, Kari ED - Korrek, Norbert ED - Pfeifer, Olaf ED - Zimmermann, Gerd T1 - DESIGNING THE REALIZABLE UTOPIA N2 - MAD is a Beijing-based architectural design studio. In their work, they are examining and developing a unique concept of futurism through current theoretical practice in architectural design, landscape design, and urban planning. In 2006, MAD was awarded the Architectural League Young Architects Forum Award. In the same year, MAD was shown at the ‘MAD in China’ exhibition in Venice during the Architecture Bienniale, and the ‘MAD Under Construction’ exhibition at the Tokyo Gallery in Beijing. MAD’s conceptual proposal, Super Star – A mobile China Town was exhibited in the Uneternal City of the 11th Architecture Biennale in Venice. Ma Yansong received his Master of Architecture from the Yale University School of Architecture in 2002. Prior to founding MAD in 2004, Mr. Ma worked as a project designer with Zaha Hadid Architects and Eisenman Architects. He also taught architecture at the Central Academy of Fine Arts in Beijing. In 2008, one of his built works, Hongluo Clubhouse, was nominated as one of the 100 designs by the London Design Museum. He was also nominated as one of the 20 most influential young architects today by ICON. KW - Architekturtheorie KW - Bauhaus KW - Architekturentwicklung Y1 - 2011 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:gbv:wim2-20170329-30598 UR - https://www.uni-weimar.de/de/architektur-und-urbanistik/professuren/theorie-und-geschichte-der-modernen-architektur/bauhaus-kolloquium/ SN - 978-3-86068-417-7 PB - Verlag der Bauhaus-Universität CY - Weimar ER - TY - JOUR A1 - Yang, Shih-Wei A1 - Budarapu, Pattabhi Ramaiah A1 - Mahapatra, D.R. A1 - Bordas, Stéphane Pierre Alain A1 - Zi, Goangseup A1 - Rabczuk, Timon T1 - A Meshless Adaptive Multiscale Method for Fracture JF - Computational Materials Science N2 - A Meshless Adaptive Multiscale Method for Fracture KW - Angewandte Mathematik KW - Strukturmechanik Y1 - 2015 SP - 382 EP - 395 ER - TY - JOUR A1 - Yaneva, Albena T1 - Obsolete ways of designing : scale models at the time of digital media technologies N2 - Wissenschaftliches Kolloquium vom 19. bis 22. April 2007 in Weimar an der Bauhaus-Universität zum Thema: ‚Die Realität des Imaginären. Architektur und das digitale Bild' T3 - Schriften der Bauhaus-Universität Weimar - 120/11 KW - Architektur KW - Design KW - Raum KW - Bild KW - Digitalisierung KW - Bauhaus-Kolloquium KW - Weimar KW - 2007 Y1 - 2008 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:gbv:wim2-20080729-13827 ER - TY - CHAP A1 - Yamabe, Yuichiro A1 - Kawamura, Hiroshi A1 - Tani, Akinori T1 - Optimal Design for Recurrent Architecture Network Harmonized with Circulation-type Societies by Applying Genetic Algorithms to Multiagent Model N2 - In this paper, a circulation-type society is expressed by recurrent architecture network described with multi-agent model which consists of the following agents: user, builder, reuse maker, fabricator, waste disposer, material maker and earth bank (see Fig.1). Structural members, materials, resources and monies move among these agents. Each agent has its own rules and aims, regarding structural damages, lifetime, cost reduction, numbers of structural members and structural systems. Reasonable prices of members (fresh, reused, recycled and disposed) can be optimized by GAs in this system considering equal distribution of monies among agents. KW - Mehragentensystem KW - Lernendes System KW - Genetischer Algorithmus Y1 - 2004 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:gbv:wim2-20111215-1892 ER - TY - CHAP A1 - Yahiaoui, Azzedine A1 - Hensen, Jan A1 - Soethout, Luc T1 - Developing CORBA-based distributed control and building performance environments by run-time coupling N2 - Communication software and distributed applications for control and building performance simulation software must be reliable, efficient, flexible, and reusable. This paper reports on progress of a project, which aims to achieve better integrated building and systems control modeling in building performance simulation by run-time coupling of distributed computer programs. These requirements motivate the use of the Common Object Request Broker Architecture (CORBA), which offers sufficient advantage than communication within simple abstraction. However, set up highly available applications with CORBA is hard. Neither control modeling software nor building performance environments have simple interface with CORBA objects. Therefore, this paper describes an architectural solution to distributed control and building performance software tools with CORBA objects. Then, it explains how much the developement of CORBA based distributed building control simulation applications is difficult. The paper finishes by giving some recommendations. KW - Ingenieurbau KW - Verteiltes System KW - Planungsprozess KW - Modellierung KW - CORBA Y1 - 2004 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:gbv:wim2-20111215-1347 ER - TY - JOUR A1 - Yabuki, Nobuyoshi A1 - Yoshimura, Yutaka T1 - An Evaluation System for Steel Structures of Hydroelectric Power Stations based on Fault Tree Analysis and Performance Maps N2 - This paper presents an evaluation system for steel structures of hydroelectric power stations, including hydraulic gates and penstocks, based on Fault Tree Analyasis (FTA) and performance maps. This system consists of fault tree diagrams of FTA, performance maps, design and analysis systems, and engineerin databases. These four modules are integrated by appropriate hyperlinks so that the user of this system can use it easily and seamlessly. A well developed system was applied to some illustrative example cases, and they showed that the developed methodology and system worked well and the users found the system useful and effective for their maintenance tasks at powerstations. KW - Wissensmanagement KW - Stahlbau KW - Wasserkraftwerk Y1 - 2004 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:gbv:wim2-20111215-2564 ER - TY - JOUR A1 - Yabuki, Nobuyoshi A1 - Kotani, Jun A1 - Shitani, Tomoaki T1 - A Steel Bridge Design System Architecture using VR-CAD and Web Service-based Multi-Agents N2 - This paper presents a new design environment based on Multi-Agents and Virtual Reality (VR). In this research, a design system with a virtual reality function was developed. The virtual world was realized by using GL4Java, liquid crystal shutter glasses, sensor systems, etc. And the Multi-Agent CAD system with product models, which had been developed before, was integrated with the VR design system. A prototype system was developed for highway steel plate girder bridges, and was applied to a design problem. The application verified the effectiveness of the developed system. KW - Mehragentensystem KW - Lernendes System KW - Stahlbrücke KW - Virtuelle Realität Y1 - 2004 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:gbv:wim2-20111215-2146 ER - TY - JOUR A1 - Xu, G. A1 - Mourrain, B. A1 - Galligo, A. A1 - Rabczuk, Timon T1 - High-quality construction of analysis-suitable trivariate NURBS solids by reparameterization methods JF - Computational Mechanics N2 - High-quality construction of analysis-suitable trivariate NURBS solids by reparameterization methods KW - Angewandte Mathematik KW - Strukturmechanik Y1 - 2014 ER - TY - JOUR A1 - Xin, Li A1 - Hijazi, Ihab Hamzi A1 - König, Reinhard A1 - Lv, Zhihan A1 - Zhong, Chen A1 - Schmitt, Gerhard T1 - Assessing Essential Qualities of Urban Space with Emotional and Visual Data Based on GIS Technique JF - ISPRS INTERNATIONAL JOURNAL OF GEO-INFORMATION N2 - Finding a method to evaluate people’s emotional responses to urban spaces in a valid and objective way is fundamentally important for urban design practices and related policy making. Analysis of the essential qualities of urban space could be made both more effective and more accurate using innovative information techniques that have become available in the era of big data. This study introduces an integrated method based on geographical information systems (GIS) and an emotion-tracking technique to quantify the relationship between people’s emotional responses and urban space. This method can evaluate the degree to which people’s emotional responses are influenced by multiple urban characteristics such as building shapes and textures, isovist parameters, visual entropy, and visual fractals. The results indicate that urban spaces may influence people’s emotional responses through both spatial sequence arrangements and shifting scenario sequences. Emotional data were collected with body sensors and GPS devices. Spatial clustering was detected to target effective sampling locations; then, isovists were generated to extract building textures. Logistic regression and a receiver operating characteristic analysis were used to determine the key isovist parameters and the probabilities that they influenced people’s emotion. Finally, based on the results, we make some suggestions for design professionals in the field of urban space optimization. KW - Stadt KW - Gefühl KW - Geoinformationssystem KW - urban form; Geographical Information System;walking experience; isovists; logistic regression Y1 - 2016 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:gbv:wim2-20170401-30995 ER - TY - CHAP A1 - Xie, Haiyan A1 - Issa, Raja A1 - O'Brien, William T1 - Structure of a Formal User Model for Construction Information Retrieval N2 - Information science researchers and developers have spent many years addressing the problem of retrieving the exact information needed and using it for analysis purposes. In informationseeking dialogues, the user, i.e. construction project manager or supplier, often asks questions about specific aspects of the tasks they want to perform. But most of the time it is difficult for the software systems to unambiguously understand their overall intentions. The existence of information tunnels (Tannenbaum 2002) aggravates this phenomenon. This study includes a detailed case study of the material management process in the construction industry. Based on this case study, the structure of a formal user model for information retrieval in construction management is proposed. This prototype user model will be incorporated into the system design for construction information management and retrieval. This information retrieval system is a user-centered product based on the development of a user configurable visitor mechanism for managing and retrieving project information without worrying too much about the underlying data structure of the database system. An executable UML model combined with OODB is used to reduce the ambiguity in the user's intentions and to achieve user satisfaction. KW - Bauwerk KW - Datenmanagement KW - Benutzeroberfläche Y1 - 2004 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:gbv:wim2-20111215-1296 ER - TY - THES A1 - Wündsch, Charlene T1 - Entrepreneurial Branding: Eine praxistheoretische Analyse markenbildender Strategiepraktiken bei Startups N2 - Gründungsunternehmen stehen vor der Herausforderung, eine unternehmerische Leistung zu entwickeln und gleichzeitig eine Markenidentität aufzubauen. Dabei sind sie mit finanziellen, personellen und strukturellen Besonderheiten konfrontiert, aber auch mit Unbekanntheit und Kundenunsicherheit. Die Dissertation zielt darauf ab, durch die Analyse markenbildender Strategiepraktiken einen Beitrag zur wissenschaftlichen Auseinandersetzung mit der Markenbildung bei Gründungsunternehmen zu leisten und praktische Implikationen für angehende Gründer:innen sowie akademische Startup-Inkubatoren abzuleiten. Der Fokus liegt dabei auf Gründungsvorhaben und Startups in der Vorgründungs- oder frühen Gründungsphase aus dem Hochschulumfeld. Zur Analyse markenbildender Strategiepraktiken wird der Strategy-as-Practice Ansatz (SAP) angewendet. Die qualitative Forschungsmethodik wird genutzt, um Handlungsmuster bestimmter Akteursgruppen in diesem spezifischen Kontext zu rekonstruieren. Beobachtungen, Interviews und Dokumente im Feld dienen als Grundlage für die Forschung. Die Ergebnisse dieser Arbeit liefern umfassende Einblicke in die markenbildende Praxis bei Gründungsunternehmen. Auf Basis dieser Erkenntnisse wurde ein Modell entwickelt, das Komponenten beschreibt, die zusammen einen Handlungsrahmen für die Markenbildung in emergenten Strategiekontexten wie der Unternehmensgründung bilden. Dieses Modell bietet die Möglichkeit, sich vor dem Hintergrund der gründungsspezifischen Rahmenbedingungen mit der Markenentwicklung in der frühen Gründungsphase auseinanderzusetzen und sie systematisch in das Gründungsvorhaben zu implementieren. KW - Entrepreneurship KW - Marke Y1 - 2023 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:gbv:wim2-20231016-64680 ER - TY - THES A1 - Wöhlecke, Guido T1 - Numerische Auswertung des Einflusses von Baugrundkenngrößen auf die Erstellung von Baugrundmodellen für ein Linienbauwerk T1 - Numeric analysis of influence from subsoilparameters to build subsoilmodels of an linear structure N2 - Die Entstehung des Baugrundes ist geprägt durch die Genese und von anthropogenen Einflüssen. In der Arbeit werden auf der Grundlage isotroper Betrachtungen im Halbraum Prognosen für unbeprobte Bereiche eines linienförmigen Bauwerkes erstellt. Aufbauend auf dem bekannten Algorithmus der Geostatistik werden Berechnungen mit deterministischen Eingangsgrößen durchgeführt. Diese sind in einem Datensatz zusammengefasst und gehen ohne Unterteilung bzw. Bildung von (Homogen)Bereichen in die Schätzungen ein. Zur Anwendung kam dabei die an der Professur Grundbau der Bauhaus-Universität Weimar entwickelte Software GeoStat. Nach der Variogrammanalyse folgten geostatistische Berechnungen mit dem Ordinary und dem Universal Kriging. Der genutzte Datensatz unterlag dabei mehrfachen Modifikationen, um Unterschiede in der Ergebnisbildung beobachten zu können. Die Krigingschätzungen wurden für subjektiv ausgewählte Beprobungspunkte erstellt, die mit Referenzprofilen verglichen werden konnten. Im Ergebnis traten für alle durchgeführten Simulationen erhebliche Abweichungen der berechneten Werte zu den Referenzprofilen auf. Die Verwendung von Datensätzen ohne eine vorherige Bearbeitung und Unterteilung in Homogenbereiche erweist sich als nicht ratsam. Vielmehr ist es notwendig kompliziertere Krigingvarianten einzusetzen bzw. die benutzten Methoden mit anderen Verfahren zu kombinieren. KW - Geostatistik KW - Baugrunduntersuchung KW - Baugrunduntersuchung KW - Geostatistische Interpolation KW - Isotropie KW - Ordinary Kriging KW - Universal Kriging Y1 - 2004 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:gbv:wim2-20111215-6732 ER - TY - JOUR A1 - Wyss, Beat T1 - News from Eurotopia : a message in a bottle between Manifesto and history by Moholy-Nagy N2 - Wissenschaftliches Kolloquium vom 24. bis 27. April 2003 in Weimar an der Bauhaus-Universität zum Thema: ‚MediumArchitektur - Zur Krise der Vermittlung' T3 - Thesis // Bauhaus-Universität - 49.2003,3/178-189 KW - Moholy-Nagy KW - L´aszló KW - Bauhaus-Kolloquium KW - Weimar KW - 2003 Y1 - 2003 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:gbv:wim2-20080228-13096 ER - TY - THES A1 - Wuttke, Frank T1 - Beitrag zur Standortidentifizierung mit Oberflächenwellen T1 - Site identification using surface waves N2 - In der Dissertation wurden unterschiedliche Methoden zur Standortidentifizierung mit Oberflächenwellen analysiert. Es wurden neue Methoden zur Parameteridentifikation unter Nutzung von Oberflächenwellen vorgeschlagen. Die Ziele der Arbeit können wie folgt definiert werden: a) Die Entwicklung eines geeigneten theoretischen Modells als Grundlage zur Untersuchung des Standortes hinsichtlich vorhandener Bodensteifigkeiten. b) Die Entwicklung einer neuen Inversionsmethodik unter Berücksichtigung aller auftretenden Moden im Oberflächenwellenfeld. Die Erstellung eines Modells des vertikal heterogenen Untergrundes erfolgte im Frequenz-bereichs für beliebig geschichtete Böden, aufbereitet durch weitestgehend analytische Formulierungen. Durch Nutzung beliebiger horizontaler, elastisch-isotroper Schichten konnte die vertikale Heterogenität approximiert werden. Die Definition der Green'schen Funktionen wurde in Form der Reflexions- und Transmissionskoeffizienten durchgeführt. Die Lösung des formulierten Halbraumproblems erfolgte unter Verwendung der Konturintegration. Dazu wurde die Vorgehensweise der bestehenden Lösung des homogenen Halbraums auf das Problem des geschichteten Mediums übertragen. Die daraus sich ergebende Lösung ist in ein Körperwellen- und ein Oberflächenwellenfeld separiert. Der Vorteil dieser analytischen Betrachtungsweise liegt in der eindeutigen Zuordnungsmöglichkeit der erhaltenen Lösungen zu Wellentypen und in der klaren Dispersionscharakteristik der berechneten Modelle. Im Gegensatz dazu liefern numerische Lösungen, wie FEM, immer ein Wellenfeld, in dem die Wellentypen zugeordnet bzw. interpretiert werden müssen. Mit Hilfe der synthetischen Bodenmodellierung wird das Verhalten von geschichteten Böden bei durchlaufenden Oberflächenwellenfeldern simuliert und untersucht. Für die Untersuchung der Profile wurde hauptsächlich die Modale Superposition von Oberflächenwellen und die Wellenzahl-Integration verwendet. Bei der Analyse von Oberflächenwellenfeldern in vorhandenen Medien sind abweichend von den üblichen seismischen Methoden spezielle Untersuchungsmethoden zur Ermittlung der vorhandenen Dispersion notwendig. Zur Durchführung der Dispersionsanalyse wird in geotechnischen Untersuchungen in der Regel das Phasen-Differenzen-Verfahren (SASW) genutzt. Aufgrund der beschränkten Aussagefähigkeit dieses Verfahrens zu auftretenden höheren Moden werden verbesserte Analysemethoden zur experimentellen Auswertung hinzugezogen. Diese Methoden nutzen zur Informationsgewinnung das räumlich ausgedehnte Wellenfeld. Ausgehend von dem Dispersionsverhalten kann die Bodenstruktur mittels inverser Methoden bestimmt werden. Für die gemeinsame Inversion der in den Messungen vorhandenen Moden wurde ein entsprechendes Inversionsverfahren abgeleitet. Als Grundlage der Inversion wurde ein Verfahren des kleinsten Fehlerquadrates gewählt. Der Vorteil hinsichtlich einer effizienten und stabilen Inversion unter Nutzung dieser Methodik überwiegt den Nachteil der lokalen Suche nach dem Fehlerminimum. Zum Erreichen der stabilen und zielgerichteten Inversion wird der Levenberg-Marquardt Algorithmus, zusammen mit der Wichtung der Dispersionsäste entsprechend ihres Anregungsverhaltens in den Dispersionsspektren, eingesetzt. Von Vorteil hat sich innerhalb der Arbeit die gleichzeitige Behandlung von theoretischen und experimentellen Parameterstudien erwiesen, da sich Ergebnisse und Erkenntnisse beider Seiten ergänzten. Eine Interpretation von Felddaten kann damit weitaus sicherer durchgeführt werden. Zusätzlich konnten die erarbeiteten experimentellen und theoretischen Verfahren gegenseitig überprüft werden. N2 - In this thesis various available methods for the site identification with surface waves were analyzed. Some new methods are proposed for the site identification using surface wave characteristics. The objectives of the thesis are as follows: a) To develop an appropriate theoretical model that can work in conjunction with the results obtained from the site inverstigations to precisely identify the actual in situ stiffness profiles. b) To develop a new inversion procedure that enables to inverse all the appearing modes in a wave field. An appropriate model should be able to define the vertical heterogeniety of the subsoil. In this study, the existing solution for the homogeneous half space was extended to the stratified medium. An analytical formulation in the frequency domain was used for this purpose by considering arbitrary horizontal, elastic isotropic layers. The Green’s functions were defined in the matrix formulation in the form of reflection- and transmission coefficients. In this way the analytical considerations could be carried out in a strong mathematical procedure. The solution for the forced excited layered half space was obtained following the contour integration. The solution could be separated in to the body wave and the surface wave fields. The advantage of such an analytical approach lies in the definite allocation of the preserved solutions for wave types and the straight dispersion characteristic of the calculated models. The difference between the analytical and the numerical solutions, such as using FEM, is that the interpretation of the calculated wave field is not required in the former, whereas it is necessary in the latter case. With the help of an analytic wave field calculation the behavior of the propagate surface wave fields in the stratified media could be better simulated and examined. For the investigation of the stiffness profiles primarily the modal superposition by surface waves and the wave number-integration were used. Special surface wave field investigation methods were necessary for the determination of the available dispersion characterisic. For the realization of the dispersion analysis in geoengineering investigations the phase difference method (SASW) is a widely used tool. Since the information on the higher modes are limited, an improved method is proposed to separate the different modes from the experimental data. The proposed method used the spatially spread wave field for the dispersion information. The soil structure can be determined by using various inverse methods. For the joint inversion of all the available modes in the measurements, a suitable inversion procedure was derived. For the stabilization of the inversion procedure, a least square method was chosen. The disadvantage of this efficient method is a local minimum search of the objective function. To achieve a stable and focused inversion procedure the Levenberg-Marquardt algorithm was used. The different dispersion branches multiplied by weighting factors corresponds to the excitation behavior in the dispersion spectra. One particularly advantage in the work is the concurrent treatment of theoretical and experimental parameter studies. According this treatment, the results and cognitions of both sides were complementary. An interpretation of field data could be carried out reliably. In addition, the compiled experimental and theoretical procedures could be checked mutually. KW - Inversionsalgorithmus KW - Inversionstheorie KW - Wellenausbreitung KW - Anomale Dispersion KW - Dispersion KW - Energieübertragung KW - wave propagation KW - inversion procedure KW - inversion theorie KW - wave field dispersion Y1 - 2004 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:gbv:wim2-20050708-6874 ER - TY - CHAP A1 - Wudtke, Idna A1 - Werner, Frank ED - Gürlebeck, Klaus ED - Könke, Carsten T1 - MODELLING OF MATERIAL PHENOMENA OF STEEL IN CONSTITUTIVE RELATIONS IN CONTEXT OF WELDING N2 - The application of partly decoupled approach by means of continuum mechanics facilitates the calculation of structural responses due to welding. The numerical results demonstrate the ability of a qualitative prediction of welded connections. As it is intended to integrate the local effects of a joint in structural analysis of steel constructions, it is necessary to meet higher approaches towards quality. The wide array of material parameters are presented, which are affecting the thermal, metallurgical and mechanical behavior, and which have to be identified. For that purpose further investigations are necessary to analyze the sensitivity of the models towards different material properties. The experimental determination of every material parameter is not possible due to the extraordinary laborious efforts needed. Besides that, experimentally identified parameters can be applied only for the tested steel quality for measured temperature-time regimes. For that reason alternative approaches for identification of material parameters, such as optimization strategies, have to be applied. After a definition of material parameters a quantitative prediction of welded connections will also be possible. Numerical results show the effect of phase transformation, activated by welding process, on residual stress state. As these phenomena occur in local areas in the range of crystal and grain sizes, the description of microscopic phenomena and their propagation on a macroscopic level due to approaches of homogenization might be expedient. Nevertheless, one should bear in mind, the increasing number of material parameters as well as the complexity of their experimental determination. Thus the microscopic approach should always be investigated under the scope of ability and efficiency of a required prediction. Under certain circumstances a step backwards, adopting a phenomenological approach, also can be beneficial. KW - Angewandte Informatik KW - Angewandte Mathematik KW - Architektur KW - Computerunterstütztes Verfahren KW - Computer Science Models in Engineering; Multiscale and Multiphysical Models; Scientific Computing Y1 - 2010 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:gbv:wim2-20170314-29032 UR - http://euklid.bauing.uni-weimar.de/ikm2009/paper.html SN - 1611-4086 ER - TY - CHAP A1 - Wudtke, Idna ED - Gürlebeck, Klaus ED - Lahmer, Tom ED - Werner, Frank T1 - CONSTITUTIVE MODELING OF CRYSTALLINE MATERIALS WITH TEXTURE CHARACTERISTICS T2 - Digital Proceedings, International Conference on the Applications of Computer Science and Mathematics in Architecture and Civil Engineering : July 04 - 06 2012, Bauhaus-University Weimar N2 - The analysis of the response of complex structural systems requires the description of the material constitutive relations by means of an appropriate material model. The level of abstraction of such model may strongly affect the quality of the prognosis of the whole structure. In context to this fact, it is necessary to describe the material in a convenient sense as exact but as simple as possible. All material phenomena of crystalline materials e.g. steel, affecting the behavior of the structure, rely on physical effects which are interacting over spatial scales from subatomic to macroscopic range. Nevertheless, if the material is microscopically heterogenic, it might be appropriate to use phenomenological models for the purpose of civil engineering. Although constantly applied, these models are insufficient for steel materials with microscopic characteristics such as texture, typically occurring in hot rolled steel members or heat affected zones of welded joints. Hence, texture is manifested in crystalline materials as a regular crystallographic structure and crystallite orientation, influencing macroscopic material properties. The analysis of structural response of material with texture (e.g. rolled steel or heat affected zone of a welded joint) obliges the extension of the phenomenological material description of macroscopic scale by means of microscopic information. This paper introduces an enrichment approach for material models based on a hierarchical multiscale methodology. This has been done by describing the grain texture on a mesoscopic scale and coupling it with macroscopic constitutive relations by means of homogenization. Due to a variety of available homogenization methods, the question of an assessment of coupling quality arises. The applicability of the method and the effect of the coupling method on the reliability of the response are presented on an example. KW - Angewandte Informatik KW - Angewandte Mathematik KW - Computerunterstütztes Verfahren Y1 - 2012 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:gbv:wim2-20170314-27910 UR - http://euklid.bauing.uni-weimar.de/ikm2012 SN - 1611-4086 ER - TY - JOUR A1 - Wray, Tim T1 - The queer gaze N2 - Wissenschaftliches Kolloquium vom 24. bis 27. April 2003 in Weimar an der Bauhaus-Universität zum Thema: ‚MediumArchitektur - Zur Krise der Vermittlung' T3 - Thesis // Bauhaus-Universität - 49.2003,4/69-73 KW - Stadt KW - Homosexualität KW - Bauhaus-Kolloquium KW - Weimar KW - 2003 Y1 - 2003 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:gbv:wim2-20080304-13356 ER -