UML (Unified Modeling Language) is a visual modeling language used for specifying, visualizing, constructing,and documenting the artifacts of software systems by various diagrams. It has been widely accepted as a stan...
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UML (Unified Modeling Language) is a visual modeling language used for specifying, visualizing, constructing,and documenting the artifacts of software systems by various diagrams. It has been widely accepted as a standard modeling language in both academic and industrial areas. UML sequence diagrams are mostly used in specifying system requirements. By representing interactions, which are arranged in time sequence,between the objects in a system,sequence diagrams can construct scenarios indicating the system's functions. A UML statechart diagram is a graph shows the sequences of states that an object or an interaction goes through during its life in response to received stimuli,together with its responses and actions. It's useful in the design stage of system development. This essay discusses the computer-aided transformation from sequence diagrams to statechart diagrams,which can offer strong support for the transfering from requirement analysis to system design in the software development process. With OCL (Object Control Language) semantic constrain,a transform algorithm is provided in the paper. And the differences with the related works are also mentioned.
Recently, the phenomenon of "software aging", one in which the state of a software system gradually de-grades with time and eventually leads to performance degradation or crash/hang failure, has been reporte...
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Recently, the phenomenon of "software aging", one in which the state of a software system gradually de-grades with time and eventually leads to performance degradation or crash/hang failure, has been reported. The agingphenomenon is ubiquitous in all kinds of software systems and hard to eliminate thoroughly. A proactive techniquecalled "software rejuvenation" has been proposed[13] to counter the aging problem and increase the software availabili-ty. In this paper, we systematically investigate the basic motivation, concept and development of software rejuvena-tion, and then, detailedly analyze the main research work on it. At last, a prospect about the future research direc-tions is outlined.
The multicast of Streaming Media over the Internet is an important component of many current and future Internet applications. The heterogeneity and lacking of QoS guarantee make the application of this technique a ch...
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The multicast of Streaming Media over the Internet is an important component of many current and future Internet applications. The heterogeneity and lacking of QoS guarantee make the application of this technique a challenge. In this paper, we analyze the difficulties in streaming media multicast design, survey technologies that have been proposed for it. We also discuss several congestion control and error control mechanisms. Finally we present some remained issues for further research.
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