摘要:

Abstract:We demonstrate the feasibility of applying image processing techniques to the analysis of pavement distress due to cracking. Pavement image samples were obtained using a custom‐designed data acquisition system called the Automatic Crack Monitor (ACM). The image samples conteining pavement cracks are parameters, are extracted using techniquesw described in this paper. The crack parameters are necessary measures used in calculations of the Pavement Serviceability Index (PSI), which is used by highway maintenance engineers to decide whether a certain pavement section needs to be repaired. Experimental results are shown and the potential harware implementation of the developed techniques is also discusse

ISSN:1093-9687    

DOI:10.1111/j.1467-8667.1991.tb00393.x

出版商:Blackwell Publishing Ltd    

年代:1991

数据来源: WILEY

摘要:

Abstract:The combined configuration of the various pipe systems in hospitals, laboratories and plants can be very complicated. They are designed by different professionals and presented on separate drawings, generally by single lines. Location of Pipe systems has to satisfy constraints on clear distances between different kinds of pipes, negative spaces for installation and maintenance, and, in some cases, minimum and maximum slopes. The single lines presentations may pose unexpected interference problems during construction, impairing the quality, cost and schedule of the project. To cope with the difficulty, allowing more flexible space is usually considered, but this approach neglects the economic factor, and interference problems may still occur.This paper presents a methodology for a three‐dimensional (3‐D) configuration of pipe systems which satisfies given constraints and which avoids interference problems during construction. The data on the building and the initial single‐line piping layout can be fed into the process either directly from the blueprints or by using AutoCAD™. The process presented in this paper then calculates the existence of any interference problems, using analytic geometry and computer graphics. If any interferences are found, a computer simulation process incrementally modifies the initial layout until all of the constraints are satisfied. The modified data are then transferred to AutoCAD™ which configures a 3‐D presentation of the pipe system. An example application, using the proposed methodology, is presented in this paper.In addition to time and cost savings during construction, the work presented in this paper has the potential of: reducing storey heights, reducing underground excavations, ensuring reasonable space for maintenance personnel, better scheduling of piping activities, and the economic benefit of considering the possibilities of the penetration of pipes through structural beams closed to the na

ISSN:1093-9687    

DOI:10.1111/j.1467-8667.1991.tb00394.x

出版商:Blackwell Publishing Ltd    

年代:1991

数据来源: WILEY

摘要:

Abstract:Computer simulation can be a powerful analytical tool. Often, however, practitioners who know most about the problem domain may have limited knowledge of the simulation software. Recent research has concentrated on bridging the gap between the practitioner and the simulatin software by designing interfaces to make computer simulation more accessible for the infrequent or inexperienced user. Emerging artificial intelligence techniques sch as knowledge‐based expert systems offer some promise for an interface. This paper describes a prototype interface which converts information on a process to be simulated into computer input for an existing computer simulation system. The elements of the interface include a domain knowledge processor using a small knowledge‐based system to establish types of activities and resources based on minimal user input, a model logic builder to identify moves between activities and to establish network logic, and a computer code translator to convert the network into CYCLONE computer source code. Recommendations for future research are inclu

ISSN:1093-9687    

DOI:10.1111/j.1467-8667.1991.tb00395.x

出版商:Blackwell Publishing Ltd    

年代:1991

数据来源: WILEY

摘要:

Abstract:Multiple techniques for modeling the air‐void system in hydrated cement paste are proposed based on uniformly dispersed spheres following a given diameter distribution. The model is developed for the analysis of air voids intersecting a random plane passed through the volume. the model is then modified for the calculation of the protected paste volume, which is the fraction of the volume contained within a given distribution of overlapping spheres. Applications of this model to other fields of study are suggeste

ISSN:1093-9687    

DOI:10.1111/j.1467-8667.1991.tb00396.x

出版商:Blackwell Publishing Ltd    

年代:1991

数据来源: WILEY

摘要:

Abstract:Effecient use of multiprocessor computers requires some consideration for formal processor shcheguling. The evolution of formal sheduling, as if relates to multiprocessor computing, is reviewd. The focus is placed on techniques which which are appropriate for numerically intensive computions, such as structural mechanics applications. Both static and dynamic scheduling tech techniques are reviewed and compared. As machine‐indepennde development environments mature, it is likely that the additional computational efficiencies available with formal scheduling will be exploite

ISSN:1093-9687    

DOI:10.1111/j.1467-8667.1991.tb00397.x

出版商:Blackwell Publishing Ltd    

年代:1991

数据来源: WILEY

摘要:

Abstract:For a microcomputer user in civil engineering, the. major factor of concern is not necessarily the computing time but the incore memory. It is particularly important for dynamic and nonlinear analyses. Solution techniques employing secondary memory to extend the capacity of a microcomputer in solving engineering problems are active research topics. There are many engineering problems which have regular data structures, e.g. tall buildings, long bridges, etc. Band matrix solution techniques are suitable for regular data structures. A partitioned matrix method is introduced for the engineering eigenvalue problem here. Static solutions are included as particular cases. FORTRAN listings are given.

ISSN:1093-9687    

DOI:10.1111/j.1467-8667.1991.tb00398.x

出版商:Blackwell Publishing Ltd    

年代:1991

数据来源: WILEY

摘要:

Abstract:The popular CAD package AutoCAD has many features making it a useful tool for finite element model generation and output postprocessing. A true ‘WYSIWYG’ interface is developed and used in and environment familiar to many Civil Engineers. The format of the interface is presented. Specific considerations for AutoLISP programming within AutoCAD and compiled language programming are discussed. A 2‐D truss structure is presented to demonstrate use of the inte

ISSN:1093-9687    

DOI:10.1111/j.1467-8667.1991.tb00399.x

出版商:Blackwell Publishing Ltd    

年代:1991

数据来源: WILEY

摘要:

Abstract:This article describes the use of ‘hypertext’ as a means to document engineering software online. An extensive hypertext document can be built with relative ease using an authoring tool. Hypertext documents enhance the learning process through the association of facts. The user has the freedom to arrange his/her own study sequence in a particular session. The article provides a brief introduction to the hypertext technology and authoring tools, and describes a Mohr's Circle program, which has been developed to explore the use of hypertext for online users' manuals. The strengths and weaknesses of the software tool, KnowledgePro, as well as the development techniques, are discus

ISSN:1093-9687    

DOI:10.1111/j.1467-8667.1991.tb00400.x

出版商:Blackwell Publishing Ltd    

年代:1991

数据来源: WILEY

ISSN:1093-9687    

DOI:10.1111/j.1467-8667.1991.tb00401.x

出版商:Blackwell Publishing Ltd    

年代:1991

数据来源: WILEY