TY - JOUR A1 - Likhitruangsilp, Veerasak A1 - Ioannou, Photios T1 - Risk-sensitive Markov Decision Process for Underground Construction Planning and Estimating N2 - This paper presents an application of dynamic decision making under uncertainty in planning and estimating underground construction. The application of the proposed methodology is illustrated by its application to an actual tunneling project—The Hanging Lake Tunnel Project in Colorado, USA. To encompass the typical risks in underground construction, tunneling decisions are structured as a risk-sensitive Markov decision process that reflects the decision process faced by a contractor in each tunneling round. This decision process consists of five basic components: (1) decision stages (locations), (2) system states (ground classes and tunneling methods), (3) alternatives (tunneling methods), (4) ground class transition probabilities, and (5) tunneling cost structure. The paper also presents concepts related to risk preference that are necessary to model the contractor’s risk attitude, including the lottery concept, utility theory, and the delta property. The optimality equation is formulated, the model components are defined, and the model is solved by stochastic dynamic programming. The main results are the optimal construction plans and risk-adjusted project costs, both of which reflect the dynamics of subsurface construction, the uncertainty about geologic variability as a function of available information, and the contractor’s risk preference. KW - Mehragentensystem KW - Lernendes System KW - Tunnel KW - Markowschke KW - Kette Y1 - 2004 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:gbv:wim2-20111215-2247 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 - van Treeck, Christoph A1 - Rank, Ernst T1 - Analysis of building structure and topology based on Graph Theory N2 - Individual views on a building product of people involved in the design process imply different models for planning and calculation. In order to interpret these geometrical, topological and semantical data of a building model we identify a structural component graph, a graph of room faces, a room graph and a relational object graph as aids and we explain algorithms to derive these relations. The application of the technique presented is demonstrated by the analysis and discretization of a sample model in the scope of building energy simulation. KW - Produktmodell KW - Simulation KW - Bautechnik KW - Graphentheorie KW - Ingenieurbau Y1 - 2004 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:gbv:wim2-20111215-2308 ER - TY - JOUR A1 - Weise, Matthias A1 - Katranuschkov, Peter A1 - Scherer, Raimar J. T1 - Generic Services for the Support of Evolving Building Model Data N2 - Many problems related to data integration in AEC can be better tackled by an approach that takes into account the heterogeneity of tasks, models and applications but does not require continuous consistency of the evolving design data, at each data management operation. Such an approach must incorporate adequate services that can facilitate reintegration of concurrently modified data at reasonably selected coordination points. In this paper we present a set of methods which, used in combination, can achieve that goal. After a description of the principal envisaged cooperative work scenario each of these methods is discussed in detail and current observations drawn from their software realisation are given. Whilst the suggested approach is valid for any EXPRESS-based data model, the practical focus of work has been on facilitating IFC-driven integration. KW - Produktmodell KW - Bautechnik KW - Forschungskooperation KW - EXPRESS Y1 - 2004 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:gbv:wim2-20111215-2077 ER - TY - JOUR A1 - Abdalla, Jamal T1 - Elements of an Agent-based Mediative Communication Protocol for Design Objects N2 - 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. KW - Mehragentensystem KW - Lernendes System KW - Kommunikationsprotokoll Y1 - 2004 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:gbv:wim2-20111215-2207 ER - TY - JOUR A1 - Gao, Zuoren A1 - Wu, Weiyu A1 - Ren, Aizhu T1 - Physically Based Modeling and Multi-Physical Simulation System for Wood Structure Fire Performance N2 - This research is devoted to promoting the performance-based engineering in wood structure fire. It looks into the characteristic of the material, structural composing and collapse detecting to find out the main factors in the wood structure collapse in fire. The aim of the research is to provide an automatic simulation platform for the complicated circulation. A physically based model for slim member for beams and columns and a frame of multi-physical simulation are provided to implement the system. The physically based model contains material model, structural mechanics model, material mechanics model, as well as geometry model for the compositive simulation. The multi-physical simulation is built on the model and has the capacity to carry out a simulation combining structural, fire (thermal, CFD) and material degradation simulation. The structural and fire simulation rely on two sophisticated software respectively, ANSYS (an FEA software) and FDS (with a core of CFD). Researchers of the paper develop system by themselves to combine the two existing ones. The system has the capability to calculate the wood char to find out the loss of cross-section and to detect the collapse caused in different ways. The paper gives a sample of Chinese traditional house to show how this simulation system works. KW - Produktmodell KW - Simulation KW - Bautechnik KW - Holzbau KW - Brandschutz Y1 - 2004 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:gbv:wim2-20111215-2381 ER - TY - JOUR A1 - Takagi, Kousuke A1 - Tani, Akinori A1 - Kawamura, Hiroshi T1 - Research on Intelligent Fuzzy Optimal Active and Hybrid Control Systems of Building Structures - Verification of Optimization Method on Switching Rules of Control Forces N2 - Recently, many reseraches on active control systems of building structures are preformed based on modern control theory and are installed real buildings. The authors have already proposed intelligent fuzzy optimal active control (IFOAC) systems. IFOAC systems imitate intelligent activities of human brains such as prediction, adaptation, decision-kaking and so on. In IFOAC systems, objective and subjective judgements on the active control can be taken into account. However, IFOAC systems are considered to be suitable for far-field erathquake and control effect becomes small in case of near-field earthqaukes which include a few velosity pules with large amplitudes. To improve control effect in case of near-souece earthquakes, the authors have also proposed hybrid control (HC) systems, in which IFOAC systems and fuzzy control system are combined. In HC systems, the fuzzy control systems are introduced as a reflective fuzzy active control (RFAC) system and imitates spinal reflection of human. In HC systems, active control forces are activated to buildings in accordance with switching rules on active control forces. In this paper, optimizations on fuzzy control rules in RFAC system and switching rules of active control forces in HC system are performed by Parameter-Free Genetic Algorithms (PfGAs). Here, the optimization is performed by using different earthquake inputs. The results of digital simulations show that the HC system can reduce maximal response displacements under restrictions on strokes of the actuator effectively in case of a near-source earthquake and the effectiveness of the proposed HC system is discussed and clarified. KW - Mehragentensystem KW - Lernendes System KW - Fuzzy-Logik KW - Optimierung Y1 - 2004 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:gbv:wim2-20111215-2238 ER - TY - JOUR A1 - Willenbacher, Heiko A1 - Hübler, Reinhard T1 - Intelligent Link-Management for the Support of Integration in Building Life Cycle N2 - The processes in the life cycle of buildings are characterised by highly distinct teamwork. The integration of all the distributed working participants, by providing an environment, which especially supports the communication and collaboration between the actors, is a fundamental step to improve the efficiency of the involved processes and to reduce the total costs. In this article, a link based modelling approach and its “intelligent” link management is introduced (1). This approach realises an integration environment based on a special building model that acts as a decision support system. The link-based modelling is characterised by the definition and specialisation of links between partial models. These intelligent managed links enable a very flexible and task specific data access and exchange between all the different views and partial models of the participants. KW - Mehragentensystem KW - Lernendes System KW - Bauwerk KW - Lebenszyklus Y1 - 2004 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:gbv:wim2-20111215-2223 ER - TY - JOUR A1 - Motawa, Ibrahim A1 - Anumba, Chimay A1 - El-Hamalawi, A. T1 - Development of a Fuzzy System for Change Prediction in Construction Projects N2 - 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. KW - Mehragentensystem KW - Lernendes System KW - Fuzzy-Logik Y1 - 2004 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:gbv:wim2-20111215-2180 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 -