摘要:

Abstract:In the past there has been a great amount of effort directed toward improving the performance of finite‐element analysis (FEA) software through improvements in equation‐solving techniques. In contrast, little attention has been given to the area of improving the input/output (I/O) transfer rate between program core and disk storage. This paper presents a method for improving the performance of FEA software by reducing the quantity of data that must be transferred between program core and disk. This is accomplished by using data‐compression techniques to compress the data during program execution, resulting in substantial decreases in program execution time and disk space usage. The paper presents a compressed I/O library written in C and the installation of the library into two FEA programs written in C and in Fortran. Results are given for personal computer, workstation, and supercomputer plat

ISSN:1093-9687    

DOI:10.1111/j.1467-8667.1994.tb00370.x

出版商:Blackwell Publishing Ltd    

年代:1994

数据来源: WILEY

摘要:

Abstract:Despite the great deal of attention given to project‐level management tools (e.g., CPM, PERT, etc.) in recent years, the analysis of construction operations (processes) using computer simulation techniques has generated considerable attention commencing with the introduction of the CYCLONE methodology. Recently, the application of visual simulation (VS) techniques to assist in the planning and analysis of construction operations has directed further attention at the need to better understand the interaction of resources at the process level. Visual simulation takes advantage of advanced modern computer graphics techniques and facilitates the development and application of simulation experiments. Benefits of applying VS have been reported in several publications. Nevertheless, the effort required to design and construct an “appropriate” VS display for the system to be analyzed is usually time and data demanding. The magnitude of model definition is often increased due to certain characteristics of construction operations, such as their complexity and the distribution of work over large areas. An alternative approach, DISCO (Dynamic Interface Simulation for Construction Operations), which employs a schematic modeling format demonstrating the system dynamics on the computer screen during simulation run, is presented in this

ISSN:1093-9687    

DOI:10.1111/j.1467-8667.1994.tb00371.x

出版商:Blackwell Publishing Ltd    

年代:1994

数据来源: WILEY

摘要:

Abstract:The design process often proceeds through iterative stages of design configuration, analysis, evaluation, and redesign with the ultimate goal of optimization. Numerical methods for structural design optimization of only one attribute such as weight, strength, or cost are well known. However, these methods do not reflect the fact that designs are evaluated by the user in terms of their performance in several attributes. It has been extremely difficult to incorporate multiple attributes into design optimization algorithms because the acceptable tradeoffs between these attributes vary significantly between users.This paper presents a new method for learning user‐specific preferences and integrating them into the design evaluation, analysis, and optimization process in a meaningful way. The approach is a synthesis of formal decision theoretic methods with conventional design analysis techniques. The overall design objective is optimization of multiattribute utility from the viewpoint of the user.A user‐interactive computer‐aided Multiattribute Structural Design Evaluation and Optimization System (MSDEOS) is presented. It enables machine learning of the user's willingness to make tradeoffs between performance attributes. With this system, it is feasible to integrate site‐specific consideration of multiple attributes directly into computer aids for structural design optimization. Two examples are presented: seismic design, where tradeoffs are made between cost and damage index, and design of a three‐story steel frame structure, where attributes are cost and drift index. The system learns the preferences of different users and reflects those preferences through the identification of a different optimal solution for

ISSN:1093-9687    

DOI:10.1111/j.1467-8667.1994.tb00372.x

出版商:Blackwell Publishing Ltd    

年代:1994

数据来源: WILEY

摘要:

Abstract:Many structural engineers only rarely need to be concerned with seismic design. It is a relatively difficult process that can involve advanced analytical techniques and concepts such as ductility which are not normally encountered except in this context. A prototype Seismic Design Assistant (SDA) has been developed specifically to assist, advise, and guide design engineers engaged in the preliminary seismic design of reinforced concrete buildings (with coupled shear walls). Available seismic design methods are reviewed, and a particular method is outlined that incorporates sophisticated analytical procedures to enable ductility requirements to be satisfied. This method provides the basis of the knowledge base employed within the SDA. The prototype design tool has been implemented on a Sun workstation using Quintec‐Prolog, Quintec‐Flex, and Fortran 77. Details are presented of the architecture of the SDA, of the knowledge representation that has been employed, and of the integration of traditional procedural software within a knowledge‐based app

ISSN:1093-9687    

DOI:10.1111/j.1467-8667.1994.tb00373.x

出版商:Blackwell Publishing Ltd    

年代:1994

数据来源: WILEY

摘要:

Abstract:Diverse problems in engineering may be solved accurately with computers. In structural engineering, many solution techniques exist. Over the past few years, neural networks have evolved as a new computing paradigm, and many engineering applications have been studied. This paper describes configuring and training of a neural network for a truss design application and explores the possible roles for neural networks in structural design problems. The specific problem considered is a simple truss design where, given a geometry and a loading, economical cross‐sectional areas of all the members are to be selected. For this problem, a two‐layer neural network is trained using the back‐propagation algorithm with patterns representing optimal designs for diverse loading conditions. The performance of the trained neural network is evaluated with a sample pr

ISSN:1093-9687    

DOI:10.1111/j.1467-8667.1994.tb00374.x

出版商:Blackwell Publishing Ltd    

年代:1994

数据来源: WILEY

摘要:

Abstract:A graphic interactive input system developed for use in computer‐aided design (CAD) of high‐rise building structures is presented. In this system, the primitive information is input to computer through graphic display. The input object appears on the screen as an image and is directly visible. With the interactive operation, the designer can carry out the input rapidly and efficiently by moving the cursor on the screen, and the graph that represents the information about the structure can be modified easily.Using multicolor graphics, animated cartoons, multiple windows, and multiple‐level menus, autogeneration and autonumbering of the members are performed, and the geometric and loading information can be input conveniently.In this paper, some basic conceptions and algorithms of graphic input and screen data collection are desc

ISSN:1093-9687    

DOI:10.1111/j.1467-8667.1994.tb00375.x

出版商:Blackwell Publishing Ltd    

年代:1994

数据来源: WILEY