指挥控制与仿真
指揮控製與倣真
지휘공제여방진
COMMAND CONTROL & SIMULATION
2014年
5期
117-123
,共7页
控制转移%Markov%变阶Markov链(VLMC)%软件可靠性%度量模型
控製轉移%Markov%變階Markov鏈(VLMC)%軟件可靠性%度量模型
공제전이%Markov%변계Markov련(VLMC)%연건가고성%도량모형
control transfer%Markov%Variable Length Markov Chain%software reliability%measurement model
针对现有软件可靠性模型普遍不适用于实际软件的问题，分析了软件内部模块间控制转移机理，通过分离入口模块，提取一阶控制转移概率矩阵；弱化内部模块与出口模块间差异，重构二阶以上转移概率矩阵，在改进Cheung模型的基础上建立一个更符合软件实际的可靠性度量模型。针对变阶依赖（ VLMC）控制转移导致的可靠性度量难问题，通过对导致复杂依赖的多入多出模块进行节点扩展，将VLMC控制流转化为Markov链，利用所建立的软件可靠性模型对VLMC控制流软件进行可靠性度量。研究利用演绎推理对所建立模型进行了正确性形式化证明。最后给出了方法的实例验证。
針對現有軟件可靠性模型普遍不適用于實際軟件的問題，分析瞭軟件內部模塊間控製轉移機理，通過分離入口模塊，提取一階控製轉移概率矩陣；弱化內部模塊與齣口模塊間差異，重構二階以上轉移概率矩陣，在改進Cheung模型的基礎上建立一箇更符閤軟件實際的可靠性度量模型。針對變階依賴（ VLMC）控製轉移導緻的可靠性度量難問題，通過對導緻複雜依賴的多入多齣模塊進行節點擴展，將VLMC控製流轉化為Markov鏈，利用所建立的軟件可靠性模型對VLMC控製流軟件進行可靠性度量。研究利用縯繹推理對所建立模型進行瞭正確性形式化證明。最後給齣瞭方法的實例驗證。
침대현유연건가고성모형보편불괄용우실제연건적문제，분석료연건내부모괴간공제전이궤리，통과분리입구모괴，제취일계공제전이개솔구진；약화내부모괴여출구모괴간차이，중구이계이상전이개솔구진，재개진Cheung모형적기출상건립일개경부합연건실제적가고성도량모형。침대변계의뢰（ VLMC）공제전이도치적가고성도량난문제，통과대도치복잡의뢰적다입다출모괴진행절점확전，장VLMC공제류전화위Markov련，이용소건립적연건가고성모형대VLMC공제류연건진행가고성도량。연구이용연역추리대소건립모형진행료정학성형식화증명。최후급출료방법적실례험증。
The classical software reliability model of Cheung based on architecture analysis is imperfect when applied to soft-ware which has non-uniqueness terminal node because of ideal assumptions. In order to handle this problem, an improved model is established through two improvement as follows:first, probability matrix of control transfer from start node to other inner nodes in a given software is computed independently of control transfer within inner nodes on the assumptions that the start node is inaccessible to control transfer from any inner nodes;and then, probability matrixes of control transfer within in-ner nodes are reconfigured by weaken the difference between inner nodes and ending nodes. In order to measure the reliability of software with VLMC control transfer flow, the variable length Markov control sequence chain is converted to simple Markov chain by node expansion and conditional transfer probability redistribution. By using deductive inference, a formal proof for the new model is given in this essay. In the end, effectiveness and simplicity of the proposed method is verified by a software example.
