Domain analysis is essential to core assets development in software product line engineering. Most existing approaches, however, depend on domain experts’ experience to analyze the commonality and variability of syst...Domain analysis is essential to core assets development in software product line engineering. Most existing approaches, however, depend on domain experts’ experience to analyze the commonality and variability of systems in a domain, which remains a manual and intensive process. This paper addresses the issue by proposing a model-driven approach to automating the domain requirements derivation process. The paper focuses on the match between the use cases of existing individual products and the domain functional requirements of a product line. By introducing a set of linguistic description dimensions to differentiate the sub-variations in a use case, the use case template is extended to model variability. To this end, a transformation process is formulated to sustain and deduce the information in use cases, and to match it to domain functional requirements. This paper also presents a prototype which implements the derivation as a model transformation described in a graphical model transformation language MOLA. This approach complements existing domain analysis techniques with less manual operation cost and more efficiency by automating the domain functional requirements development.展开更多
Requirements analysis and design specification are serious issues in systems development because of the semantics involved in transformation of real world problems to computer software systems. Although unified modeli...Requirements analysis and design specification are serious issues in systems development because of the semantics involved in transformation of real world problems to computer software systems. Although unified modeling language (UML) is now accepted as a de facto standard for design and specification of object oriented systems but its structures have various disadvantages. For example, it lacks of defining semantics of the systems to be developed. Formal me-thods are proved powerful, particularly, at requirement specification and design level. To address and realize the bene-fits of UML and formal methods our project on “formalization of UML diagrams using Z notation” is under progress. This paper is continuation of the same project in which some important diagrams namely use case, class and sequence diagrams are selected for critical analysis. Merits and demerits of the diagrams are addressed after a brief introduction. Applications of the diagrams are observed reducing complexity and proposing a good design of a system. Finally, a treatment to link diagrams with appropriate approaches is suggested to enhance modeling power of UML for facilitating the systems development.展开更多
Based on the different roles played by base flow and alternative flow in the process to achieve user＇s goals, we have found that loop structure is frequently used to implement alternative flow and/or to connect diffe...Based on the different roles played by base flow and alternative flow in the process to achieve user＇s goals, we have found that loop structure is frequently used to implement alternative flow and/or to connect different use cases. This paper presents an approach to identify base flows and alternative flows of different use cases by traversing control flow graph in which back edges are eliminated. The effectiveness of the approach is verified by identification of the use case structure of an ATM system. The workload of human intervention of the approach is relatively slight, and the manner of human intervention closely follows the usual process of software comprehension.展开更多
Nonlinear solution of reinforced concrete structures, particularly complete load-deflection response, requires tracing of the equilibrium path and proper treatment of the limit and bifurcation points. In this regard, ...Nonlinear solution of reinforced concrete structures, particularly complete load-deflection response, requires tracing of the equilibrium path and proper treatment of the limit and bifurcation points. In this regard, ordinary solution techniques lead to instability near the limit points and also have problems in case of snap-through and snap-back. Thus they fail to predict the complete load-displacement response. The arc-length method serves the purpose well in principle, received wide acceptance in finite element analysis, and has been used extensively. However modifications to the basic idea are vital to meet the particular needs of the analysis. This paper reviews some of the recent developments of the method in the last two decades, with particular emphasis on nonlinear finite element analysis of reinforced concrete structures.展开更多
文摘Domain analysis is essential to core assets development in software product line engineering. Most existing approaches, however, depend on domain experts’ experience to analyze the commonality and variability of systems in a domain, which remains a manual and intensive process. This paper addresses the issue by proposing a model-driven approach to automating the domain requirements derivation process. The paper focuses on the match between the use cases of existing individual products and the domain functional requirements of a product line. By introducing a set of linguistic description dimensions to differentiate the sub-variations in a use case, the use case template is extended to model variability. To this end, a transformation process is formulated to sustain and deduce the information in use cases, and to match it to domain functional requirements. This paper also presents a prototype which implements the derivation as a model transformation described in a graphical model transformation language MOLA. This approach complements existing domain analysis techniques with less manual operation cost and more efficiency by automating the domain functional requirements development.
文摘Requirements analysis and design specification are serious issues in systems development because of the semantics involved in transformation of real world problems to computer software systems. Although unified modeling language (UML) is now accepted as a de facto standard for design and specification of object oriented systems but its structures have various disadvantages. For example, it lacks of defining semantics of the systems to be developed. Formal me-thods are proved powerful, particularly, at requirement specification and design level. To address and realize the bene-fits of UML and formal methods our project on “formalization of UML diagrams using Z notation” is under progress. This paper is continuation of the same project in which some important diagrams namely use case, class and sequence diagrams are selected for critical analysis. Merits and demerits of the diagrams are addressed after a brief introduction. Applications of the diagrams are observed reducing complexity and proposing a good design of a system. Finally, a treatment to link diagrams with appropriate approaches is suggested to enhance modeling power of UML for facilitating the systems development.
基金Supported by the Major Research Plan of the National Natural Science Foundation of China(90818027)the Key Program of the National Natural Science Foundation of China(60633010)+2 种基金the National Natural Science Foundation of China (60873050,60873049,60803008)the Natural Science Foundation of Jiangsu Province of China(BK2006094,BK2008292)the Opening Foundation of State Key Laboratory of Software Engineering in Wu-han University (SkLSE20080717)
文摘Based on the different roles played by base flow and alternative flow in the process to achieve user＇s goals, we have found that loop structure is frequently used to implement alternative flow and/or to connect different use cases. This paper presents an approach to identify base flows and alternative flows of different use cases by traversing control flow graph in which back edges are eliminated. The effectiveness of the approach is verified by identification of the use case structure of an ATM system. The workload of human intervention of the approach is relatively slight, and the manner of human intervention closely follows the usual process of software comprehension.
文摘Nonlinear solution of reinforced concrete structures, particularly complete load-deflection response, requires tracing of the equilibrium path and proper treatment of the limit and bifurcation points. In this regard, ordinary solution techniques lead to instability near the limit points and also have problems in case of snap-through and snap-back. Thus they fail to predict the complete load-displacement response. The arc-length method serves the purpose well in principle, received wide acceptance in finite element analysis, and has been used extensively. However modifications to the basic idea are vital to meet the particular needs of the analysis. This paper reviews some of the recent developments of the method in the last two decades, with particular emphasis on nonlinear finite element analysis of reinforced concrete structures.
