@article{MotawaAnumbaElHamalawi2004, author = {Motawa, Ibrahim and Anumba, Chimay and El-Hamalawi, A.}, title = {Development of a Fuzzy System for Change Prediction in Construction Projects}, doi = {10.25643/bauhaus-universitaet.218}, url = {http://nbn-resolving.de/urn:nbn:de:gbv:wim2-20111215-2180}, year = {2004}, abstract = {Change management has been the focus of different IT systems. These IT systems were developed to represent design information, record design rationale, facilitate design coordination and changes. They are largely based on managing reactive changes, particularly design changes, in which changes are recorded and then propagated to the relevant project members. However, proactive changes are hardly dealt with in IT systems. Proactive changes require estimating the likelihood of occurrence of a change event as well as estimating the degree of change impacts on project parameters. Changes in construction projects often result from the uncertainty associated with the imprecise and vague knowledge of much project information at the early stages of projects. This is a major outcome of the case studies carried out as part of this research. Therefore, the proposed model considers that incomplete knowledge and certain project characteristics are always behind change causes. For proactive changes, predicting a change event is the main task for modelling. The prediction model should strive to integrate these main elements: 1) project characteristics that lead to change 2) causes of change, 3) the likelihood of change occurrence, and 4) the change consequences. It should also define the dependency relationships between these elements. However, limited data (documented) are only available from previous projects for change cases and many of the above elements can only be expressed in linguistic terms. This means that the model will simulate the uncertainty and subjectivity associated with these sets of elements. Therefore, a fuzzy model is proposed in this research to capture these elements. The model analyses the impact of each set of elements on the other by assigning fuzzy values for these elements that express the uncertainty and subjectivity of their impact. The main aim is to predict change events and evaluate change effects on project parameters. The fuzzy model described above was developed in an IT system for operational purposes and was designed as a Java package of components with their supporting classes, beans, and files. This paper describes the development and the architecture of the proposed IT system to achieve these requirements. The system is intended to help project teams in dealing with change causes and then the change consequences in construction projects.}, subject = {Mehragentensystem}, language = {en} } @article{FoorgberMueller1997, author = {Foorgber, U. and M{\"u}ller, Christian}, title = {A Planning Process Model for Computer Supported Cooperative Work in Building Construction}, doi = {10.25643/bauhaus-universitaet.492}, url = {http://nbn-resolving.de/urn:nbn:de:gbv:wim2-20111215-4922}, year = {1997}, abstract = {Increasing complexity of today's buildings requires a high level of integration in the planning process. Common planning strategies, where individual project partners cooperate mainly to exchange results, are not suitable to jointly develop project goals and objectives. Integrated planning, a more holistic approach to deal with complex problems, is based on a high degree of communication amoung team members and leads to a goal oriented cooperation. Current approaches in the reasearch area of Computer Supported Cooperative Work (CSCW) poorly meet the requirements in planning. A planning process model, based on the principles of integrated planning will be introduced, aimed to provide the background for the implementation of a CSCW-platform.}, subject = {Bauwesen}, language = {en} } @article{YabukiYoshimura2004, author = {Yabuki, Nobuyoshi and Yoshimura, Yutaka}, title = {An Evaluation System for Steel Structures of Hydroelectric Power Stations based on Fault Tree Analysis and Performance Maps}, doi = {10.25643/bauhaus-universitaet.256}, url = {http://nbn-resolving.de/urn:nbn:de:gbv:wim2-20111215-2564}, year = {2004}, abstract = {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.}, subject = {Wissensmanagement}, language = {en} } @article{KicingerArciszewskiDeJong2004, author = {Kicinger, Rafal and Arciszewski, Tomasz and De Jong, Kenneth}, title = {Distributed Evolutionary Design: Island-Model-based Optimization of Steel Skeleton Structures in Tall Buildings}, doi = {10.25643/bauhaus-universitaet.219}, url = {http://nbn-resolving.de/urn:nbn:de:gbv:wim2-20111215-2195}, year = {2004}, abstract = {This paper presents results of a study on distributed, or parallel, evolutionary computation in the topological design of steel structural systems in tall buildings. It describes results of extensive experimental research on various parallel evolutionary architectures applied to a complex structural design problem. The experiments were conducted using Inventor 2003, a networkbased evolutionary design support tool developed at George Mason University. First, a general introduction to evolutionary computation is provided with an emphasis on recent developments in parallel evolutionary architectures. Next, a discussion of conceptual design of steel structural systems in tall buildings is presented. Further, Inventor 2003 is briefly introduced as well as its design representation and evolutionary computation characteristics. Next, the results obtained from systematic design experiments conducted with Inventor 2003 are discussed. The objective of these experiments was to qualitatively and quantitatively investigate evolution of steel structural systems in tall buildings during a distributed evolutionary design process as well as to compare efficiency and effectiveness of various parallel evolutionary architectures with the traditional evolutionary design approaches. Two connectivity topologies (ring topology and fully-connected topology) have been investigated for four populations of structural designs evolving in parallel and using various migration strategies. Also, results of the initial sensitivity studies are reported in which two ways of initializing distributed evolutionary design processes were investigated, using either arbitrarily selected designs as initial parents or randomly generated ones. Finally, initial research conclusions are presented.}, subject = {Mehragentensystem}, language = {en} } @article{MilbradtSchierbaumSchwoeppe2004, author = {Milbradt, Peter and Schierbaum, Jochen and Schw{\"o}ppe, Axel}, title = {Finite Cell-Elements of Higher Order}, doi = {10.25643/bauhaus-universitaet.252}, url = {http://nbn-resolving.de/urn:nbn:de:gbv:wim2-20111215-2524}, year = {2004}, abstract = {The method of the finite elements is an adaptable numerical procedure for interpolation as well as for the numerical approximation of solutions of partial differential equations. The basis of these procedure is the formulation of suitable finite elements and element decompositions of the solution space. Classical finite elements are based on triangles or quadrangles in the two-dimensional space and tetrahedron or hexahedron in the threedimensional space. The use of arbitrary-dimensional convex and non-convex polyhedrons as the geometrical basis of finite elements increases the flexibility of generating finite element decompositions substantially and is sometimes the only way to get a clear decomposition...}, subject = {Finite-Elemente-Methode}, language = {en} } @article{ElRayesHyari2004, author = {El-Rayes, Khaled and Hyari, Khalied}, title = {A Multi-objective Model for Optimizing Construction Planning of Repetitive Infrastructure Projects}, doi = {10.25643/bauhaus-universitaet.213}, url = {http://nbn-resolving.de/urn:nbn:de:gbv:wim2-20111215-2135}, year = {2004}, abstract = {This paper presents the development of a model for optimizing resource utilization in repetitive infrastructure projects. The model provides the capability of simultaneous minimization of both project duration and work interruptions for construction crews. The model provides in a single run, a set of nondominated solutions that represent the tradeoff between these two objectives. The model incorporates a multiobjective genetic algorithm and scheduling algorithm. The model initially generates a randomly selected set of solutions that evolves to a near optimal set of tradeoff solutions in subsequent generations. Each solution represents a unique scheduling solution that is associated with certain project duration and a number of interruption days for utilized construction crews. As such, the model provides project planners with alternative schedules along with their expected duration and resource utilization efficiency.}, subject = {Mehragentensystem}, language = {en} } @article{Rueppel1997, author = {R{\"u}ppel, Uwe}, title = {Multimediale Gestaltung von Bestandsverwaltungsprozessen im Bauwesen}, doi = {10.25643/bauhaus-universitaet.483}, url = {http://nbn-resolving.de/urn:nbn:de:gbv:wim2-20111215-4839}, year = {1997}, abstract = {Die Kosten f{\"u}r die Unterhaltung von Bauwerken {\"u}ber den Lebenszyklus sind im Vergleich zu den Planungs- und Herstellungskosten erheblich gr{\"o}ßer. Insbesondere setzt eine Reduzierung des Instandhaltungsaufwandes als Teilprozeß der Bestandsverwaltung das rechtzeitige Erkennen von Bausch{\"a}den und das vorausschauende Ergreifen von Gegenmaßnahmen voraus. Das planm{\"a}ßige Vorgehen beim Erkennen von Bausch{\"a}den, d.h. die regelm{\"a}ßige {\"U}berwachung baulicher Anlagen, dient nicht nur dem sparsamen Umgang mit vorhandenen Mitteln, sondern verringert auch die Gefahr des pl{\"o}tzlichen Versagens von tragenden Bauteilen. Dadurch werden Gefahren f{\"u}r die Nutzer der Bauwerke fr{\"u}hzeitig abgewendet. Die Notwendigkeit der systematischen Instandhaltung mit modernen Methoden wird auch in den Schlußfolgerungen des dritten Bauschadensberichts des Bundesministeriums f{\"u}r Raumordnung, Bauwesen und St{\"a}dtebau unterstrichen. Um den Zustand eines Bauteils festzustellen, werden ausreichende Informationen {\"u}ber Struktur, Material, Alter, Belastungen, Umweltbedingungen etc. ben{\"o}tigt. Zur Verarbeitung dieser F{\"u}lle von Informationen unterschiedlichen Typs (z.B. technische Dokumente, CAD-Zeichnungen, Photos etc.) bei der {\"U}berwachung und Dokumentation baulicher Anlagen ist eine geeignete DV-Unterst{\"u}tzung notwendig. Zur Verwaltung der komplexen Baustrukturinformationen werden objektorientierte Bauwerksmodelle ben{\"o}tigt. Zur bedarfsgerechten Aufbereitung der unterschiedlichen Informationsarten und -qualit{\"a}ten ist zus{\"a}tzlich eine multimediale Informationsverarbeitung sowohl intern als auch in der Benutzungsschnittstelle erforderlich. Im Beitrag werden die Grundlagen objektorientierter Methoden zur Bauwerksmodellierung sowie von Multimedia mit den Bereichen Text, Graphik (Vektor- und Pixelgraphik), Audio, Photo und Video einschließlich deren Verkn{\"u}pfungsm{\"o}glichkeiten im Sinne von Hypermedia an Beispielen erl{\"a}utert. Zus{\"a}tzlich werden aktuelle Entwicklungstendenzen im Bereich der Telekommunikation mit den M{\"o}glichkeiten des Computernetzes INTERNET zur Bestandsverwaltung in verteilten Systemen aufgezeigt. Abschließend werden Anwendungen der objektorientierten und multimedialen Informationsverarbeitung in der t{\"a}glichen Ingenieurpraxis am Beispiel des DV-Systems BestandManager zur {\"U}berwachung und Dokumentation baulicher Anlagen vorgestellt.}, subject = {Bauwerk}, language = {de} } @article{KaklauskasCervenkaCervenka2004, author = {Kaklauskas, Gintaris and Cervenka, Vladimir and Cervenka, Jan}, title = {Deflection Calculation of RC Beams: Finite Element Software versus Design Code Methods}, doi = {10.25643/bauhaus-universitaet.249}, url = {http://nbn-resolving.de/urn:nbn:de:gbv:wim2-20111215-2498}, year = {2004}, abstract = {The paper investigates accuracy of deflection predictions made by the finite element package ATENA and design code methods ACI and EC2. Deflections have been calculated for a large number of experimental reinforced concrete beams reported by three investigators. Statistical parameters have been established for each of the technique at different load levels, separately for the beams with small and moderate reinforcement ratio.}, subject = {Finite-Elemente-Methode}, language = {en} } @article{MinchTrochanowski1997, author = {Minch, M. J. and Trochanowski, A.}, title = {The numerical Modelling and Analysis of RC cracked Structures}, doi = {10.25643/bauhaus-universitaet.527}, url = {http://nbn-resolving.de/urn:nbn:de:gbv:wim2-20111215-5278}, year = {1997}, abstract = {The purpose of this paper is to review model for finite element techniques for non-linear crack analysis of reinforced concrete beams and slabs. The non-linear behaviour of concrete and steel were described. Some calculations of >self-stress< for concrete and reinforced concrete beam was made. Current computational aspects are discussed. Several remarks for future studies are also given. The numerical model of the concrete and reinforced concrete was described. The paper shows the results of calculations on a reinforced concrete plane stress panel with cracks. The non-linear, numerical model of calculations of reinforced concrete was assumed. Using finite elements method some calculations were made. The results of calculations like displacements, stresses and cracking are shown on diagrams. They were compared with experimental results and other finding. Some conclusions about the described model and results of calculation are shown.}, subject = {Tragwerk}, language = {en} } @article{Dudek1997, author = {Dudek, Mariusz}, title = {Zur Bewertung der Struktur von Verkehrsnetzen}, doi = {10.25643/bauhaus-universitaet.463}, url = {http://nbn-resolving.de/urn:nbn:de:gbv:wim2-20111215-4634}, year = {1997}, abstract = {In diese Ver{\"o}ffentlichung werden die Kennziffern dargestellt, die zur Beurteilung der Struktur von Verkehrsnetzen behilflich sein k{\"o}nnen. Zu diesem Zweck wurde die Graphentheorie angewendet. Eine erste Gruppe von Bewertungen st{\"u}tzt sich auf die Anzahl der Knoten und B{\"o}gen des Netzes. Detailliertere Informationen {\"u}ber Engp{\"a}sse oder Schwachstellen im Verkehrsnetz erh{\"a}lt man durch die Analyse der Kantenzusammenhangs. Die Unabh{\"a}ngigkeit der einzelnen Verkehrsarten , ihre Bewertung und Maßnahmen, sie zu verbessern werden vorgeschlagen und diskutiert. Weiteren Untersuchungen werden angeregt.}, subject = {Verkehrsnetz}, language = {de} }