摘要:

Abstract:An IVHS (Intelligent Vehicle Highway System) information management system obtains information from road sensors, city maps and event schedules, and generates information to drivers, pafie controllers and researchers. We extend the relational database to model traffic information in a relational database by abstract data types and triggers. Abstract data types are needed for eficient modeling of spatial and temporal information, which create inefficiencies in traditional databases. We use monotonic continuous functions to map the object locations to disk addresses to save disk space and computation time. Model of spatial data is created to efficiently process moving objects. We provide schema for IVHS databases with the relevant abstract data types. We also have a large sample of the relations needed to model IVHS data. Several interesting queries are presented to show the power of the model. Triggers are defined, using rule‐definition mechanisms to represent incident detection and warning systems. An eficient physical model with MoBiLe access method is provide

ISSN:1093-9687    

DOI:10.1111/j.1467-8667.1993.tb00204.x

出版商:Blackwell Publishing Ltd    

年代:1993

数据来源: WILEY

摘要:

Abstract:This paper presents an object‐oriented data management model for numerical analysis in computer‐aided engineering. A data storage structure and an index system have been developed for complex data objects encountered in numerical analysis. As an example, the model is applied to the finite element analy

ISSN:1093-9687    

DOI:10.1111/j.1467-8667.1993.tb00205.x

出版商:Blackwell Publishing Ltd    

年代:1993

数据来源: WILEY

摘要:

Abstract:Knowledge acquisition for developing design knowledge bases is difficult and time consuming. In this paper, a new approach for acquiring design knowledge is presented. The object‐oriented approach is applied to model the design objects and the design process. It is discussed that in the case of routine bridge design, synthesis of the bridge structure can be achieved through recursive top‐down refinement using selection among predefined types, and decomposition of the structure into predefined components. Having this design model, a methodology for using analogy to augment the knowledge base is proposed. Analogy can be used to retrieve and modib an available design object in order to create a similar object interactively. A prototype system that implements this methodology is presen

ISSN:1093-9687    

DOI:10.1111/j.1467-8667.1993.tb00206.x

出版商:Blackwell Publishing Ltd    

年代:1993

数据来源: WILEY

摘要:

Abstract:This paper describes an object‐oriented approach to the detailed design of structures. The objects and class relationships for the design of any structural system are identified at a high level of abstraction. It is shown that object‐oriented programming promotes modulariy, flexibiliy and extendibility, and this is illustrated through specialization of the class hierarchy identified for the general design case to a specific design example. Object‐oriented programming also allows for an eficient way of handling design heuristics, and this is illustrated by associating heuristics with the design objects of a specific example. The model is being implemented in C++ on a 386 microcom

ISSN:1093-9687    

DOI:10.1111/j.1467-8667.1993.tb00207.x

出版商:Blackwell Publishing Ltd    

年代:1993

数据来源: WILEY

摘要:

Abstract:An idealized model for analysis of multistory buildings subjected to lateral loads is presented. Using a simplified structural model composed of connecting beams and columns, along with a rapid condensation procedure, an approximated lateral stiffness matrix is obtained from which the lateral deformations can be quickly determined. The proposed model is suitable either for preliminary analysis or for quick verification of more complex computational procedures.Commonly used analytical procedures are based on one of the following two approaches: (i] rapid evaluation of story drifts based on oversimplification of structures as specified primarily by building codes (shear systemslstick models), and (ii) detailed modeling of buildings as an assemblage of structural members combined with refined analysis of each individual component (finite element analysis). While the former approach requires only a small amount of data and simple hand computations to carry out the analysis, the latter requires an abundance of information and fairly complicated and elaborate computations requiring computers. However, the first approach leads only to very approximate results often invalidated by severe assumptions and restrictions while the second method produces results which are more comprehensive and accurate.The idealization proposed in this paper is a rational combination of the two approaches leading to more accurate results with only a minimal amount of data. The simplification is obtained by assuming contraflexure points at mid spans of horizontal beams, but not extending the same simplification to vertical elements, as is typically done in simplified design and code approaches. This allows a simple representation of beams as rotational springs coupled to vertical cantilevers representing the columns. The ensuing matrix computations on a vastly reduced and diagonalized stiffness matrix can be carried out with ease on microcomputers.Using the procedure outlined herein, the internal forces in members can be reasonably obtained, and axial stresses can be roughly estimated. An application of the proposed technique is presented using two sample buildings and are compared with results of more rigorous and accurate procedures.

ISSN:1093-9687    

DOI:10.1111/j.1467-8667.1993.tb00208.x

出版商:Blackwell Publishing Ltd    

年代:1993

数据来源: WILEY

摘要:

Abstract:An iso‐response analysis is presented for the nonlinear dynamic response of blast loaded stiffened plates. This analysis is based on a new rigid‐plastic grillage modelling of stiffened plates. The analysis provides iso‐response curves in two‐dimensional peak pressure versus total impulse space for particular structures which can be used directly for design purposes. Representative results are presented for several one‐ and two‐way stiff

ISSN:1093-9687    

DOI:10.1111/j.1467-8667.1993.tb00209.x

出版商:Blackwell Publishing Ltd    

年代:1993

数据来源: WILEY