@article{Abdalla2004, author = {Abdalla, Jamal}, title = {Elements of an Agent-based Mediative Communication Protocol for Design Objects}, doi = {10.25643/bauhaus-universitaet.220}, url = {http://nbn-resolving.de/urn:nbn:de:gbv:wim2-20111215-2207}, year = {2004}, abstract = {Integrated structural engineering system usually consists of large number of design objects that may be distributed across different platforms. These design objects need to communicate data and information among each other. For efficient communication among design objects a common communication protocol need to be defined. This paper presents the elements of a communication protocol that uses a mediator agent to facilitate communication among design objects. This protocol is termed the Mediative Communication Protocol (MCP). The protocol uses certain design communication performatives and the semantics of an Agent Communication language (ACL) mainly the Knowledge and Query Manipulation Language (KQML) to implement its steps. Details of a Mediator Agent, that will facilitate the communication among design objects, is presented. The Unified Modeling Language (UML) is used to present the Meditative protocol and show how the mediator agent can be use to execute the steps of the meditative communication protocol. An example from structural engineering application is presented to demonstrate and validate the protocol. It is concluded that the meditative protocol is a viable protocol to facilitate object-to-object communication and also has potential to facilitate communication among the different project participants at the higher level of integrated structural engineering systems.}, subject = {Mehragentensystem}, language = {en} } @article{AlbertFreischladPullmann2004, author = {Albert, Andrej and Freischlad, Mark and Pullmann, Torben}, title = {Acquisition of Conceptual Design Knowledge in Structural Engineering}, doi = {10.25643/bauhaus-universitaet.215}, url = {http://nbn-resolving.de/urn:nbn:de:gbv:wim2-20111215-2154}, year = {2004}, abstract = {Expert systems integrating fuzzy reasoning techniques represent a powerful tool to support practicing engineers during the early stages of structural design. In this context fuzzy models have proved themselves to be very suitable for the representation of complex design knowledge. However their definition is a laborious task. This paper introduces an approach for the design and the optimization of fuzzy systems based upon Genetic Programming. To keep the emerging fuzzy systems transparent a new framework for the definition of linguistic variables is also introduced.}, subject = {Mehragentensystem}, language = {en} } @article{AzizAnumbaMiles2004, author = {Aziz, Zeeshan and Anumba, Chimay and Miles, John}, title = {Towards a Semantic Grid Computing Platform for Disaster Management in Built Environment}, doi = {10.25643/bauhaus-universitaet.208}, url = {http://nbn-resolving.de/urn:nbn:de:gbv:wim2-20111215-2084}, year = {2004}, abstract = {Current disaster management procedures rely primarily on heuristics which result in their strategies being very cautious and sub-optimum in terms of saving life, minimising damage and returning the building to its normal function. Also effective disaster management demands decentralized, dynamic, flexible, short term and across domain resource sharing, which is not well supported by existing distributing computing infrastructres. The paper proposes a conceptual framework for emergency management in the built environment, using Semantic Grid as an integrating platform for different technologies. The framework supports a distributed network of specialists in built environment, including structural engineers, building technologists, decision analysts etc. It brings together the necessary technology threads, including the Semantic Web (to provide a framework for shared definitions of terms, resources and relationships), Web Services (to provide dynamic discovery and integration) and Grid Computing (for enhanced computational power, high speed access, collaboration and security control) to support rapid formation of virtual teams for disaster management. The proposed framework also make an extensive use of modelling and simulation (both numerical and using visualisations), data mining (to find resources in legacy data sets) and visualisation. It also include a variety of hardware instruments with access to real time data. Furthermore the whole framework is centred on collaborative working by the virtual team. Although focus of this paper is on disaster management, many aspects of the discussed Grid and Visualisation technologies will be useful for any other forms of collaboration. Conclusions are drawn about the possible future impact on the built environment.}, subject = {Mehragentensystem}, language = {en} } @article{BakurovaPerepelitsaZin'kovskaya1997, author = {Bakurova, A. V. and Perepelitsa, V. A. and Zin'kovskaya, J. S.}, title = {Research of Stability of Vector Problem of spanning Tree with topological Criteria}, doi = {10.25643/bauhaus-universitaet.515}, url = {http://nbn-resolving.de/urn:nbn:de:gbv:wim2-20111215-5159}, year = {1997}, abstract = {A multicriterial statement of the above mentioned problem is presented. It differes from the classical statement of Spanning Tree problem. The quality of solution is estimated by vector objective function which contains weight criteria as well as topological criteria (degree and diameter of tree). Many real processes are not determined yet. And that is why the investigation of the stability is very important. Many errors are connected with calculations. The stability analysis of vector combinatorial problems allows to discover the value of changes in the initial data for which the optimal solution is not changed. Furthermore, the investigation of the stability allows to construct the class of the problems on base of the one problem by means of the parameter variations. Analysis of the problems with belong to this class allows to obtaine axact and adecuate discription of model}, subject = {Spannender Baum}, language = {en} } @article{BeerFirmenichRichter2004, author = {Beer, Daniel G. and Firmenich, Berthold and Richter, Torsten}, title = {A Concept for CAD Systems with Persistent Versioned Data Models}, doi = {10.25643/bauhaus-universitaet.204}, url = {http://nbn-resolving.de/urn:nbn:de:gbv:wim2-20111215-2046}, year = {2004}, abstract = {The synchronous distributed processing of common source code in the software development process is supported by well proven methods. The planning process has similarities with the software development process. However, there are no consistent and similarly successful methods for applications in construction projects. A new approach is proposed in this contribution.}, subject = {Produktmodell}, language = {en} } @article{BerkowskiBoron1997, author = {Berkowski, P. and Boron, Jacek}, title = {An Algorithm of compromise structural Optimisation of Bar Structures}, doi = {10.25643/bauhaus-universitaet.526}, url = {http://nbn-resolving.de/urn:nbn:de:gbv:wim2-20111215-5264}, year = {1997}, abstract = {Authors' own research in applied unicriterial and multicriterial optimisation of bar structures, and also an analysis of accessible bibliography on structural synthesis allows to present herein an attempt to define a general algorithm for proceeding in formulation of a structural optimisation problem. A practical aspect of such an algorithm consists, in author's opinion, in enabling a designer a correct creation of a mathematical model of synthesis problems, independently of known mathematical methods employed to looking for an unconditional extremum of function of several variables. A proposed algorithm is not a ready-for-use tool for solving all the optimisation problems, but it constitutes an easy-to-expand theoretical basis. This basis should allow a designer to create a proper set of compromises on the way to construct a mathematical model of a specific optimisation problem. The algorithm, presented in the paper, is constructed as a sequence of the one-after-another problem questions, on which the designer answers: yes or no, and a set of selections from the knowledge base consisting of the elements of an optimisation problem components. The order of making questions adopted by the authors in the algorithm is subjective, however it is supported by their experience, both in applied optimisation and in designing of structures like trusses or frames.}, subject = {Stabwerk}, language = {en} } @article{BucherSchorling1997, author = {Bucher, Christian and Schorling, York}, title = {SLang - the Structural Language : Solving Nonlinear and Stochastic Problems in Structural Mechanics}, doi = {10.25643/bauhaus-universitaet.495}, url = {http://nbn-resolving.de/urn:nbn:de:gbv:wim2-20111215-4957}, year = {1997}, abstract = {Recent developments in structural mechanics indicate an increasing need of numerical methods to deal with stochasticity. This process started with the modeling of loading uncertainties. More recently, also system uncertainty, such as physical or geometrical imperfections are modeled in probabilistic terms. Clearly, this task requires close connenction of structural modeling with probabilistic modeling. Nonlinear effects are essential for a realistic description of the structural behavior. Since modern structural analysis relies quite heavily on the Finite Element Method, it seems to be quite reasonable to base stochastic structural analysis on this method. Commercially available software packages can cover deterministic structural analysis in a very wide range. However, the applicability of these packages to stochastic problems is rather limited. On the other hand, there is a number of highly specialized programs for probabilistic or reliability problems which can be used only in connection with rather simplistic structural models. In principle, there is the possibility to combine both kinds of software in order to achieve the goal. The major difficulty which then arises in practical computation is to define the most suitable way of transferring data between the programs. In order to circumvent these problems, the software package SLang (Structural Language) has been developed. SLang is a command interpreter which acts on a set of relatively complex commands. Each command takes input from and gives output to simple data structures (data objects), such as vectors and matrices. All commands communicate via these data objects which are stored in memory or on disk. The paper will show applications to structural engineering problems, in particular failure analysis of frames and shell structures with random loads and random imperfections. Both geometrical and physical nonlinearities are taken into account.}, subject = {Baustatik}, language = {en} } @article{Caetano1997, author = {Caetano, A. M.}, title = {Eigenvalue Distribution for the Stokes Operator}, doi = {10.25643/bauhaus-universitaet.500}, url = {http://nbn-resolving.de/urn:nbn:de:gbv:wim2-20111215-5005}, year = {1997}, abstract = {The aim of this talk is to show that the methods used by M{\´e}tivier and Lapidus to study the eigenvalue distribution of elliptic operators (e.g., of the Dirichlet Laplacian) can be adapted to the study of the similar problem for the Stokes operator. In this way we get asymptotic formulae for the eigenvalues of the latter operator even in the case when the underlying domain has an extremely irregular (fractal) boundary. In the case the boundary is not that irregular (e.g., when it is Lipschitz) the estimates we obtain are much better than the ones we can find in the current literature.}, subject = {Stokes-Problem}, language = {en} } @article{CerovsekTurk2004, author = {Cerovsek, Tomo and Turk, Ziga}, title = {Working Together: ICT Infrastructures to Support Collaboration}, doi = {10.25643/bauhaus-universitaet.205}, url = {http://nbn-resolving.de/urn:nbn:de:gbv:wim2-20111215-2055}, year = {2004}, abstract = {The paper summarizes a part of research carried out in ICCI project and provides a current review of ICT infrastructures supporting collaboration. It covers taxonomies, protocols, standards, components, typical subsystems as well as future trends and recommendation for two most important technologies with applications in AEC: (1) EIP (Enterprise information portal) - a single gateway to a company's information, knowledge base, and applications for all actors; (2) RTC (Real-Time Communication and Collaboration technologies) that provide means for asynchronous communication between geographically dislocated people using ICT. Proposed future developments are: orientation towards web services - with building information models, business intelligence, personalization, AEC information retrieval, p2p workspaces and grids.}, subject = {Informationstechnik}, language = {en} } @article{ChangChangHuang2004, author = {Chang, Chihyuan and Chang, Yuanchu and Huang, Shyhmeng}, title = {Application of a Agent Mechanism to the Small-scale Maintenance of School Buildings}, doi = {10.25643/bauhaus-universitaet.216}, url = {http://nbn-resolving.de/urn:nbn:de:gbv:wim2-20111215-2165}, year = {2004}, abstract = {This paper presents an agent-based software, Virtual Administrator System (VAS) for the smallscale maintenance of school buildings. VAS is capable of handling a heavy load of routine, lowtech maintenance jobs. It assigns a different priority to each job application according to its significance and urgency, and automatically adjusts schedules for maintenance engineers when on-site supervision is needed. The system can help ease off the burden of routine small-scale maintenance work, making it more cost-effective and efficient in the overall management of school building maintenance. VAS posts jobs on the Web in a multi-media format and classified all applications into four categories: the on-call maintenance contract, the term maintenance contract, the guaranty maintenance contract, and the regular maintenance contract. It then estimates their urgency level and passes the information to maintenance engineers who will decide whether on-site inspection is needed. Based on the engineers' feedback, VAS automatically implements the scheduling for inspection as well as sends out real-time or batch notifications to contractors. All these activities are recorded in a database to allow continuous research and data mining and the analysis and diagnosis of specific jobs for followup maintenance plans.}, subject = {Mehragentensystem}, language = {en} } @article{DonathPetzold1997, author = {Donath, Dirk and Petzold, Frank}, title = {Zuk{\"u}nftige Techniken f{\"u}r eine computergest{\"u}tzte Planungspraxis - applikative Tools f{\"u}r die architektonische Bestandserfassung}, doi = {10.25643/bauhaus-universitaet.496}, url = {http://nbn-resolving.de/urn:nbn:de:gbv:wim2-20111215-4962}, year = {1997}, abstract = {Der Beitrag beschreibt die Entwicklung eines Softwaresystems zur strukturierten Erfassung und Verwaltung bestehender Geb{\"a}ude in der Architektur. Die Erfassung erfolgt durch die Aufnahme von geometrischen Daten und Sachdaten in unterschiedlichen Abstraktionsstufen unter Einbeziehung einer vorangehenden Dekomposition. Basis f{\"u}r die Entwicklung eines solchen Systems ist die Analyse und Systematik der Erfassungstechniken, -abl{\"a}ufe und der Gegenstand der architektonischen Bestandsaufnahme. Parallel hierzu erfolgt die Bewertung und Nutzung aktueller Techniken und Werkzeuge der applikativen Informatik. Schwerpunkte der Forschungsarbeit sind die Ableitung einer allgemeinen Geb{\"a}ude- und Bauteilstruktur, die Einbeziehung aktueller informationstechnischer Verfahren und Werkzeuge und die Entwicklung eines entsprechenden Experimentalsystems. Auf eine Auswahl softwaretechnischer Entwicklungen wird n{\"a}her eingegangen (objektspezifische Eigenschaften, flexible Geometrieerfassung und Benutzeroberfl{\"a}chen).}, subject = {Bauaufnahme}, language = {de} } @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} } @article{Dudek1997, author = {Dudek, Mariusz}, title = {Modellierung der Verkehrsmittelwahl}, doi = {10.25643/bauhaus-universitaet.481}, url = {http://nbn-resolving.de/urn:nbn:de:gbv:wim2-20111215-4817}, year = {1997}, abstract = {Die Zielstellung der Modal­Split­Betrachtungen l{\"a}uft darauf hinaus, Entscheidungs-kriterien zu erarbeiten, nach denen die einzelnen Personen ihre Verkehrsmittel ausw{\"a}hlen. In dieser Ver{\"o}ffentlichung wurden alle drei Gruppen der Modelle (klassische, verhaltensorientierte und der Analyse) der Verkehrsaufteilung kurz charakterisiert. Dann wurden vier ausgew{\"a}hlte Modelle genauer beschrieben. Zum Schluß wird das Modell der Verkehrsmittelwahl dargestellt , das f{\"u}r die Untersuchung der Verkehrsaufteilung in Krakau verwendet wurde .}, subject = {Verkehrsmittelwahl}, language = {de} } @article{Dzwigon1997, author = {Dzwigon, Wieslaw}, title = {Sch{\"a}tzung der Verkehrs-Verteilung (O-D Matrix) bei der Anwendung der Verkehrsst{\"a}rkemessung in den Straßenquerschnitten}, doi = {10.25643/bauhaus-universitaet.464}, url = {http://nbn-resolving.de/urn:nbn:de:gbv:wim2-20111215-4647}, year = {1997}, abstract = {O-D Matrix sind die wichtigste Informationsquelle, die den Bedarf an Transport in der Stadt betrifft. Sie dienen den richtigen Bildung von Straßennetz und {\"O}ffentlichen Personen Verkehrslinien. Anhand diesen Grundlagen gerechnet man Verkehrsst{\"a}rken, die zur Dimensionierung der Verkehrsinfrastruktur benutzt werden. Im Verkehrsplannung zur Rechnung O-D Matrix wird Vier - Stufen - Methode angewendet. In dieser Methode verwendet man die Angaben aus den Haushaltsumfragen und aus den Kordonumfragen. Diese Methode fordert einen großen Arbeitsaufwand und Kosten. Hier wird die andere Methode dargestellt. Bei Sch{\"a}tzung der O-D Matrix verwendet man die Verkehrsst{\"a}rken, die in den Straßenquerschnitten gemessen werden. Wir brauchen gemessene Verkehrsst{\"a}rken auch f{\"u}r andere Ziele (z. B. f{\"u}r Signalsteuerung, f{\"u}r Beobachtung des Motorisierungstrendes). Darum ist diese Methode billiger als das traditionelle Verfahren. In diesen Methode haben wir zwei M{\"o}glichkeiten. Die erste - von Verkehrsst{\"a}rkemessungen kann man O-D Matrix direkt sch{\"a}tzen. Und zweite M{\"o}glichkeit - zuerst rechnen wir die Verkehrserzeugungen und sp{\"a}ter O-D Matrix. Das zweite Verfahren hat einen wesentlichen Vorteil und zwar, anhand der Verkehrserzeugungen ist es m{\"o}glich alle Elemente O-D Matrix zu rechnen. Bei der Sch{\"a}tzung der O-D Matrix unmittelbar von den Messungen (das erste Verfahren) bekommt man nur diese Elemente, die in den beobachtenen Straßenquerschnitten auftreten.}, subject = {Stadtverkehr}, language = {de} } @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{EmelichevGirlichPodkopaev1997, author = {Emelichev, V. A. and Girlich, E. and Podkopaev, D. P.}, title = {Several kinds of Stability of efficient Solutions in Vector Trajectorial discrete Optimization Problem}, doi = {10.25643/bauhaus-universitaet.503}, url = {http://nbn-resolving.de/urn:nbn:de:gbv:wim2-20111215-5030}, year = {1997}, abstract = {This work was partially supported by DAAD, Fundamental Researches Foundation of Belarus and International Soros Science Education Program We consider a vector discrete optimization problem on a system of non- empty subsets (trajectories) of a finite set. The vector criterion of the pro- blem consists partial criterias of the kinds MINSUM, MINMAX and MIN- MIN. The stability of eficient (Pareto optimal, Slater optimal and Smale op- timal) trajectories to perturbations of vector criterion parameters has been investigated. Suficient and necessary conditions of eficient trajectories local stability have been obtained. Lower evaluations of eficient trajectories sta- bility radii, and formulas in several cases, have been found for the case when l(inf) -norm is defined in the space of vector criterion parameters.}, subject = {Diskrete Optimierung}, language = {en} } @article{Erlemann2004, author = {Erlemann, Kai}, title = {BABSIM - An object-oriented software framework for microscopic simulation of freeway traffic}, doi = {10.25643/bauhaus-universitaet.260}, url = {http://nbn-resolving.de/urn:nbn:de:gbv:wim2-20111215-2601}, year = {2004}, abstract = {A wide variety of behavioural models exist in microscopic traffic simulation. Commercial programms often use closed-source policies and are confined to their respective simulation platforms. Open-source approaches mainly focus on distinctive, highly specialized traffic situations. In the scope of this paper, an open-source framework for developing modular, objectoriented simulation systems is presented, capable of simultaneously accommodating different driving models and enabling the user to modify and extend the catalogue of driving behaviours. The existing driving behaviours and the computational implementation of the simulation are being described.}, subject = {Framework }, language = {en} } @article{Fink2004, author = {Fink, Thomas}, title = {Structural analysis, design and detailing using standard CAD software and standard building information model}, doi = {10.25643/bauhaus-universitaet.270}, url = {http://nbn-resolving.de/urn:nbn:de:gbv:wim2-20111215-2702}, year = {2004}, abstract = {This paper describes the concept of a german commercial software package developed for the needs of structural engineers. Using a standard CAD software as user interface for all geometrical data and to save all important input data, there is a natural link to upcoming building information models.}, subject = {Bauindustrie}, language = {en} } @article{Firmenich2004, author = {Firmenich, Berthold}, title = {Product Models in Network Based Co-operation in Structural Engineering}, doi = {10.25643/bauhaus-universitaet.211}, url = {http://nbn-resolving.de/urn:nbn:de:gbv:wim2-20111215-2119}, year = {2004}, abstract = {The Priority Programme 'Network Based Co-operation in Structural Engineering' of the 'German Research Foundation' (DFG) has been established in the year 2000. This paper describes and discusses the main research directions and first results of the workgroup 'Distributed Product Models'. The five projects of the workgroup have developed completely different solutions for specific application domains. Each solution concept deals with a consistent product modeling and knowledge processing in a distributed environment in the planning process. The individual solution approaches of the projects are described and the underlying basic assumptions are discussed. A unified system architecture is described for all projects of the workgroup. Two different approaches (object-oriented and graph-based models) have been introduced for product and knowledge modeling. The common structure of these models will be explained to fully understand the differences of these modeling approaches. Finally the concepts for co-operative work and conflict management in a distributed environment are described: The solution approaches will be distinguished by classifying the supported co-operation according to time. A final scientific summary describes the state-of-the-art in network based co-operation in structural engineering: The role of research directions like knowledge modeling, standard product modeling and versioning in the distributed planning process will be explained.}, subject = {Produktmodell}, language = {en} } @article{FischerSteinhage1997, author = {Fischer, A. and Steinhage, V.}, title = {Ein modellbasiertes Konzept zur st{\"a}dteplanerischen Kartierung durch digitale Bildanalyse}, doi = {10.25643/bauhaus-universitaet.487}, url = {http://nbn-resolving.de/urn:nbn:de:gbv:wim2-20111215-4870}, year = {1997}, abstract = {There is an increasing need for 3D building extraction from aerial images for various applications such astown planning, environmental- and property-related studies. Aerial images usually reveal on one hand a certain amount of information not relevant for the given task of building extraction like vegetation, cars etc. On the other hand there is a loss of relevant information due to occlusions, low contrasts or disadvantageous perspectives. Therefore a promising concept for automated building reconstruction must incorporate a suffciantly complete model of the objects of interest. We propose a model-based approach to 3D building extraction from aerial images which reveals a tight coupling between a generic 3D object model and an explicit 2D image model. The generic object model employes domain specific volumetric primitives (i. e. building part models) and combination schemes. To cover the gap between 3D object models and 2D image data the image model is employed to predict the projective building appearences in aerial images. We present a strategy for a model-based building extraction based on the recognition-by-components principle and show first experimental results derived from international test sets}, subject = {Stadtplanung}, language = {de} }