The study proposes a combination of the function points model for software estimation with the ADISSA methodology for systems analysis and design. This combined approach, which is supported by a software tool, enables...
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This paper describes a market driven life cycle methodology for application of off-the-shelf products and provides anecdotal lessons for each of the life cycle phases. In order to form a framework for further discussi...
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This paper describes a market driven life cycle methodology for application of off-the-shelf products and provides anecdotal lessons for each of the life cycle phases. In order to form a framework for further discussion, a model of the off-the-shelf marketplace is introduced to define a range of products from low cost commodities to high-end niche or specialty items. Within this framework, strategies are recommended for defining product requirements both technical and programmatic, surveying the market to find products that meet those requirements and then acceptance testing those products to ensure they do in fact perform as advertised. Recommendations are provided in the area of product tailoring, if tailoring is deemed a cost effective alternative to unique design. The pitfalls of managing ''off-the-shelf'' vendors as subcontractors during the tailoring phase is also described. Product procurement is defined to include not only those steps required to procure product quantities for deploy ment but also steps to ensure that those products meet the same requirements as those accepted during the selection phase. Three product support strategies are next described. The strategies range from a traditional ''commercial'' approach with support provided within the vendor's infrastructure to a more traditional ''military'' approach in which vendors are subcontracted to provide longer term support. Selection of the appropriate strategy is based on a balance of cost, desired product life and desired level of stability within the system configuration.
The study proposes a combination of the function points model for software estimation with the ADISSA methodology for systems analysis and design. This combined approach, which is supported by a software tool, enables...
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The study proposes a combination of the function points model for software estimation with the ADISSA methodology for systems analysis and design. This combined approach, which is supported by a software tool, enables one to estimate various software metrics, such as size, effort, and duration, in the early stages of systems development, by basing them on the products of a thorough system analysis and design process.
作者：
Okano, KHigashino, TTaniguchi, KMemberFaculty of Engineering Science
Osaka University Toyonaka Japan 560 Teruo Hipshino received his B.E.
M.E.and Ph.D. degrees in Information and Computer Sciences from Osaka University Osaka Japan in 1R9 1981 and 1984 respectively. He joined the Faculty of Osaka University in 1984. Since 1991 he has been an Associate Professor in the Department of Information and Computer Sciences at Osaka University. In 1990 he was a Visiting Researcher of Dept. I.R.O. at University of Montreal Canada. His current research interests include design and analysis of distributed systems specification and verification of communication protocols and formal approach of program design. He is a member of IEEE-CS ACMIEICE of Japanand IPS of Japan.
In this paper, new methods for providing the correctness of refinement among abstract sequential machine style programs are described. The programs are described in algebraic language ASL using some useful notions, i....
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In this paper, new methods for providing the correctness of refinement among abstract sequential machine style programs are described. The programs are described in algebraic language ASL using some useful notions, i.e., the extended projection and the valid reachability condition for each transition function. These notions allow a designer to refine a given text (program or specification) to a concrete text more freely than the text that does not use such notions. These notions can also enhance the expressive power of the text. On the other hand, these advantages would have lost half their values, if useful methods to prove the correctness of refinement among the texts using them are not found. Thus new methods for proving the correctness of the texts are proposed, and they do not require much proof loads. First, the correctness of refinement among the ASL texts with the extended projection is defined. Second, a method is proposed for proving the correctness of refinement among such texts. Also proposed is a definition of the correctness of refinement among the texts with the valid reachability conditions and a method to prove their correctness. These methods do not require more proof loads than the usual methods for the texts that do not use such notions in the abstract sequential machine style. Therefore, these methods are useful.
This paper is a case study of how problem resolution can operate in the life cycle maintenance stage of a large tactical sonar system. Here, the system design agent is not the original designer, so the principles of o...
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This paper is a case study of how problem resolution can operate in the life cycle maintenance stage of a large tactical sonar system. Here, the system design agent is not the original designer, so the principles of operation, hardware and software architecture, and test tools need to be learned. To deal with this challenge, the system design agent evolved a team approach that integrates the talents of a program manager, a system engineer, a test engineer, and a software engineer to analyze fleet problems. This team has proven effective at localizing problems for repair. Lessons are drawn to further improve maintenance efficiency.
作者：
POND, LCLI, VOKCommunication Sciences
Electrical Engineering Systems University of Southern California Los Angeles CA 90089-2565 U.S.A. Lawrence C. Pond received the M.Sc. and Ph.D. degrees in electrical engineering from the University of Southern California in 1983 and 1990
respectively. Dr. Pond is currently a scientist at Hughes Space and Communications Company having joined in 1980. He has worked in the fields of communication system design mobile communication network and spacecraft payload design. He is currently working on the development of satellite-based ATM transport and switching architectures for BISDN and Defense Information System Network amlications. Dr. Pond is a member of IEEE. Victor O. K. Li was born in Hong Kong in 1954. He received his SB
SM and Sc.D. degrees in Electrical Engineering and Computer Science from the Massachusetts Institute of Technology Cambridge Massachusetts in 1977 1979 and 1981 respectively. Since February 1981 he has been with the University of Southern California (USC) LOS Angeles California where he is Professor of Electrical Engineering and Director of the USC Communication Sciences Institute. He has published 150 technical papers and has lectured and consulted extensively around the world. His research interests include high-speed communication networks personal communication networks intelligent networks distributed databases queueing theory graph theory and applied probability. Dr. Li is very active in the Institute of Electrical and Electronic Engineers (IEEE) having been a member of the Computer Communications Technical Committee since 1983 and having served as Chairman from 1987–1989. He served as Chairman of the Los Angeles Chapter of the IEEE Information Theory Group from 1983–1985. He is the Steering Committee Chair of the International Conference on Computer Communications and Networks (IC3 N) General Chair of the 1st Annual IC3N held in San Diego California in June 1992 General Chair and Technical Program Chair of the 4th IEEE Workshop on Comp
In this, the second part of a two-part paper, the required time for establishing a mobile packet radio network using the virtual circuit and time division multiple access protocol developed in Part 1 is analysed. Tool...
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In this, the second part of a two-part paper, the required time for establishing a mobile packet radio network using the virtual circuit and time division multiple access protocol developed in Part 1 is analysed. Tools are developed to determine the virtual circuit and network set-up times in terms of the channel bandwidth allocated to establish and maintain the network. The tools are then extended to include the effects of user mobility. Then these results are combined with the network capacity results of Part 1 to analyse the trade-off between the data rate and set-up time of the network. Next a hierarchical architecture is proposed and the network data rate versus set-up time trade-off of this architecture is analysed using these tools. This architecture is shown to both provide a higher data rate and establish faster than flat networks of the same number of nodes.
The subband adaptive system, where the idea of the filter bank is applied to the adaptive filter, has a feature that a higher-order adaptation can be reduced to lower-order adaptations. The reduction of the order of t...
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The subband adaptive system, where the idea of the filter bank is applied to the adaptive filter, has a feature that a higher-order adaptation can be reduced to lower-order adaptations. The reduction of the order of the adaptive filter is related closely to the number of channels and the decimation ratio. The order of adaptive digital filter (ADF) is decreased greatly when the number of subbands is increased, and the decimation ratio is increased up to the maximum value. Then, however, the number of coefficient-updates per unit time is decreased, which results in the deterioration of the convergence Speed. From such a viewpoint, this paper discusses a method to improve the convergence speed, which is deteriorated in the subband adaptive system, due to the decimation. The idea of the proposed method is to utilize effectively the data which have been discarded in the decimation process and to improve the convergence speed. It is called the multirate repeating method. As the first step, the multirate repeating method is applied to the conventional subband adaptive system and the convergence speed is improved. Then a subband adaptive system is introduced in which the multirate repeating method can be utilized more effectively. As a result, a faster convergence is realized while retaining the ADF order-reduction effect, which is an advantage of the subband adaptive system.
This paper describes the implementation of transmission-line matrix (TLM) method algorithms on a massively parallel computer (DECmpp 12000), the technique of distributed computing in the UNIX environment, and the comb...
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This paper describes the implementation of transmission-line matrix (TLM) method algorithms on a massively parallel computer (DECmpp 12000), the technique of distributed computing in the UNIX environment, and the combination of TLM analysis with Prony's method as well as with autoregressive moving average (ARMA) digital signal processing for electromagnetic field modelling. By combining these advanced computation techniques, typical electromagnetic field modelling of microwave structures by TLM analysis can be accelerated by a few orders of magnitude.
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