摘要:

Abstract:A CAD/CAM system that automates the design and manufacturing of rebars is described. The CAD‐based design module of the system permits a semiautomated design alongside the conventional one. The uniqueness of the system resides in its ability to extract automatically the data needed for manufacturing from the graphic design database, process these data, and transfer them to the rebar‐manufacturing machine. Thus all the manual data manipulation stages of traditional rebar design and production (detailing, documentation, data extraction, etc.) are avoided. In many cases the multistage manual data manipulation is a source of errors and is moreover labor‐intensive. Consequently, the CAD/CAM system described here leads to cost reduction together with increased quality. This paper describes the principles underlying the development of the system and the system's structure, which is based on a design module, a data extraction module, and a data processing and transfer m

ISSN:1093-9687    

DOI:10.1111/j.1467-8667.1995.tb00299.x

出版商:Blackwell Publishing Ltd    

年代:1995

数据来源: WILEY

摘要:

Abstract:The aim of this paper is to focus on special items of research and development (R&D) areas in which Taisei Corporation is active, to discuss some of the issues involved in automation research and the importance of information management in automation and robotics, and to delve into the possible future of construction robotics and automation. In the first section we break automation and robotics down into four levels: simple mechanization, robots, mechanized construction systems, and fully automated construction. Each is discussed separately and, with the exception of fully automated construction, examples of R&D in each category are described. This gives the reader a glimpse of what a general contractor in Japan is currently doing. In the second section we describe information‐integrated construction (IIC), which can be defined as the use of computer technology to collect, store, manipulate, enhance, and display construction information and expertise as a way to streamline the construction proces

ISSN:1093-9687    

DOI:10.1111/j.1467-8667.1995.tb00300.x

出版商:Blackwell Publishing Ltd    

年代:1995

数据来源: WILEY

摘要:

Abstract:In this paper, paying attention to the steps of making a master plan and evaluating configurations and views for aesthetic design of bridge structures, an attempt is made to develop a decision‐making supporting system. The present system is based on a genetic algorithm and computer graphics. Genetic algorithms are applicable to produce many design alternatives, whereas computer graphics are useful to prepare their view simulations. In order to evaluate the alternatives, the concept of a psychovector is used to quantify the aesthetic factors of bridge structures. A numerical example of choosing the type and shape of an arched bridge is presented to demonstrate the applicability of the system developed her

ISSN:1093-9687    

DOI:10.1111/j.1467-8667.1995.tb00301.x

出版商:Blackwell Publishing Ltd    

年代:1995

数据来源: WILEY

摘要:

Abstract:Advances in performance of local area networks and microprocessors are providing significant computational capability at a relatively low cost. This paper is concerned with development of a distributed algorithm for minimum weight design of large structures on a network of workstations using biologically inspired genetic algorithms. Communication constructs from the software library Parallel Virtual Machine (PVM) have been used for message passing between the workstations. The algorithm has been applied to minimum weight design of two example structures. Performance estimates are provided based on the granularity and parallelization efficiency of the distributed model. The speedup of the distributed algorithm increases with the size of the structure, making it particularly suitable for optimization of large structures. For large structures, a high average speedup of about 10 is achieved using 11 workstations. The high scalability of the distributed genetic algorithm demonstrates that a cluster of workstations provides a cost‐effective alternative for high‐performance computing for coarse‐grained applications such as the GA‐based structural optim

ISSN:1093-9687    

DOI:10.1111/j.1467-8667.1995.tb00302.x

出版商:Blackwell Publishing Ltd    

年代:1995

数据来源: WILEY

摘要:

Abstract:This paper presents an overview of the neural‐network technique as a management tool for maintenance of flexible pavement. The paper discusses the development and implementation of a neural network for the condition rating of roadway sections. The condition‐rating scheme developed by Oregon State Department of Transportation was used as the basis for the development of the network presented. A training set of 744 cases was used to train the network, and a set of 1736 cases was used to test the generalization ability of the system. The network adequately learned the training examples with an average training error of 0.019 and was able to determine the correct condition ratings with an average testing error of 0.023. The network's ability to deal with noisy data also was tested. Up to 60% noise was added to the data and introduced to the network. The results showed that the network presented could identify condition rating relationships at high levels of‐noise. Finally, an expert determination was compared with that produced by the network. The network was able to mimic the expert's condition ratings with an average error of 0

ISSN:1093-9687    

DOI:10.1111/j.1467-8667.1995.tb00303.x

出版商:Blackwell Publishing Ltd    

年代:1995

数据来源: WILEY

摘要:

Abstract:Two approaches for parallel implementation of nonlinear transient dynamic analysis algorithms have been presented in this paper. One is based on geometric decomposition, and the other one is processor‐farm approach. Both shared memory (Magnum IV) and transputer‐based message‐passing systems have been chosen for implementation of the proposed parallel algorithms for dynamic analysis. Multithread concepts have been employed on transputer networks to optimize the code by overlapping communications with computations. Numerical studies indicate that explicit transient dynamic analysis can be implemented effectively employing geometric decomposition technique both on shared and message‐passing

ISSN:1093-9687    

DOI:10.1111/j.1467-8667.1995.tb00304.x

出版商:Blackwell Publishing Ltd    

年代:1995

数据来源: WILEY