摘要:

Suppose a real symmetric general matrix A is reduced into a real symmetric tridiagonal matrix C by either Householder's method or Givens method. Eigenvalues of the tridiagonal matrix are the eigenvalues of the original matrix since they are similar. After eigenvalues are calculated, the eigenvectors of the original matrix may be obtained by the eigenvectors of the tridiagonal matrix and the transformation matrices used in either Householder's or Givens tridiagonalization methods [1]. In these methods, however, transformation matrices usually are not stored due to memory considerations. Only critical information such as rotation angles in Givens method is saved. Generally, the recovery of all transformation matrices involves more computation than the tridiagonalization procedure. Therefore such a scheme is rarely used. In this paper, a serial eigenvector solution procedure, assuming eigenvalues are known, is first described. This procedure applies Gauss elimination with diagonal pivoting on the characteristic equations. A parallel procedure is then developed by using scattered column decomposition. The efficiency and speedup are given in terms of problem and machine parameters. The efficiency of the parallel algorithm increases as the number of scattered columns assigned to each processor increases, and decreases as communication cost between processors increases.

ISSN:1093-9687    

DOI:10.1111/j.1467-8667.1989.tb00018.x

出版商:Blackwell Publishing Ltd    

年代:1989

数据来源: WILEY

摘要:

The integrated structural design includes preliminary design, structural analysis, and the final detailed design. A knowledge‐based expert system for integrated structural design requires both symbolic processing of heuristics and experiential knowledge and numerical processing of algorithmic computations. In addition, such a coupled expert system must use existing data bases as well as a large variety of data created during a consultation with the system. Thus, considering their complex interaction, effective integration of symbolic processing, numerical processing, and data base management becomes a major concern in the development of expert systems for integrated structural design. This paper addresses this integration problem by presenting a prototype system, called FRAMEX, for design of a class of steel structures—regular multistory steel buildings. The basis of steel design is the recently developed Load and Resistance Factor Design Specificat

ISSN:1093-9687    

DOI:10.1111/j.1467-8667.1989.tb00019.x

出版商:Blackwell Publishing Ltd    

年代:1989

数据来源: WILEY

摘要:

This paper shows that object‐oriented generic application frameworks can be used to improve the design and implementation of interactive engineering software. Enhanced development time, consistency, transparency, flexibility, and quality are achieved by separating programs into generic and domain‐specific components. Advantages of object‐oriented programming over conventional procedure‐oriented approaches are highlighted for the development of basic interactive software (event‐driven architectures, user‐interface standards, etc.). A language‐independent model is used to provide the implementation details for a generic application framework called “GenApp.” Programs can be constructed on top of this framework by creating specialized object classes that selectively mix inherited generic behavior with application‐specific tasks. Customized user‐interface, object management, and support for existing procedures are some of the features offered by GenApp to simplify the development of engineering software. A finite‐element analysis program is shown as an example product of this generi

ISSN:1093-9687    

DOI:10.1111/j.1467-8667.1989.tb00020.x

出版商:Blackwell Publishing Ltd    

年代:1989

数据来源: WILEY

摘要:

A mathematical model for simulating the dispersion mechanism of the carbon monoxide concentration 300 m outside a vehicular tunnel located near a hillside is reported. This is achieved by solving a system of partial differential equations describing diffusion of the pollutants with turbulent effects. Simplified geographical profile, vehicles queue, and local wind conditions are taken into account. The model has been implemented in a Microsoftfortran4.1 program that can run on an IBM‐AT 286 or a Deskpro 386 microcompute

ISSN:1093-9687    

DOI:10.1111/j.1467-8667.1989.tb00021.x

出版商:Blackwell Publishing Ltd    

年代:1989

数据来源: WILEY

摘要:

Network‐scheduling techniques are used extensively to determine a project's duration. Two of the most popular techniques are the critical path method (CPM) and the probabilistic evaluation and review technique (PERT). Only one of these techniques, PERT, includes a capability to evaluate the risk in the duration of a project. But, PERT has some inherent limitations which affect the user's ability to effectively evaluate risk or variability of project duration. Computer simulation is a way to overcome the limitations of CPM and PERT. This paper describes a method to simulate schedule networks using an existing simulation package calledcyclone. The correspondence between a CPM network and acyclonenetwork is developed and an example of simulating a small network is presented. Computer output and recommended improvements are discusse

ISSN:1093-9687    

DOI:10.1111/j.1467-8667.1989.tb00022.x

出版商:Blackwell Publishing Ltd    

年代:1989

数据来源: WILEY

摘要:

The subspace iteration for symmetric real matrices is extended to the partial eigensolutions for Hermitian matrices. Only the lower triangle of the Hermitian matrix in variable band form is required and processed. Efficient and compactfortransubroutines are developed for computing the lowest modes in ascending order of absolute eigenvalues. The method is suitable for incore microcomputer solution of the sparse Hermitian eigenvalue problem.

ISSN:1093-9687    

DOI:10.1111/j.1467-8667.1989.tb00023.x

出版商:Blackwell Publishing Ltd    

年代:1989

数据来源: WILEY

ISSN:1093-9687    

DOI:10.1111/j.1467-8667.1989.tb00024.x

出版商:Blackwell Publishing Ltd    

年代:1989

数据来源: WILEY

ISSN:1093-9687    

DOI:10.1111/j.1467-8667.1989.tb00025.x

出版商:Blackwell Publishing Ltd    

年代:1989

数据来源: WILEY