The basis graph \%G\% for a linear programming consists of all bases under pivot transformations. A degenerate optimal basis graph G * is a subgraph of \%G\% induced by all optimal bases at a degenerate optimal verte...The basis graph \%G\% for a linear programming consists of all bases under pivot transformations. A degenerate optimal basis graph G * is a subgraph of \%G\% induced by all optimal bases at a degenerate optimal vertex x 0. In this paper, several conditions for the characterization of G * are presented.展开更多
Let be an undirected graph. The maximum cycle packing problem in G then is to find a collection of edge-disjoint cycles C<sub>i</sup>in G such that s is maximum. In general, the maximum cycle packing probl...Let be an undirected graph. The maximum cycle packing problem in G then is to find a collection of edge-disjoint cycles C<sub>i</sup>in G such that s is maximum. In general, the maximum cycle packing problem is NP-hard. In this paper, it is shown for even graphs that if such a collection satisfies the condition that it minimizes the quantityon the set of all edge-disjoint cycle collections, then it is a maximum cycle packing. The paper shows that the determination of such a packing can be solved by a dynamic programming approach. For its solution, an-shortest path procedure on an appropriate acyclic networkis presented. It uses a particular monotonous node potential.展开更多
随着软件在各个领域的广泛应用,软件漏洞呈不断增长的趋势,基于深度学习的软件漏洞检测方法得到广泛应用;然而,现有的图表示学习方法通常忽略了图中边对软件漏洞检测的影响,并且对边权重的表示过于粗糙。针对该问题,提出一种基于边权重...随着软件在各个领域的广泛应用,软件漏洞呈不断增长的趋势,基于深度学习的软件漏洞检测方法得到广泛应用;然而,现有的图表示学习方法通常忽略了图中边对软件漏洞检测的影响,并且对边权重的表示过于粗糙。针对该问题,提出一种基于边权重的软件漏洞检测方法EWVD(Edge Weight for Vulnerability Detection)。首先,对源代码中的注释、自定义变量名和函数名进行清理和抽象表示;其次,经过对比分析后选择使用Sent2Vec进行嵌入表示;再次,利用连接结构、邻居节点的重要性和Jaccard相似性这3种度量方式,综合计算边权重,从而识别节点间的信息传递能力;最后,利用边权重提升模型对漏洞语句潜在关系的感知能力,从而判断图中边的重要性。实验结果表明,与7种漏洞检测基线方法中的最优基线VulCNN相比,EWVD的准确率提高了1.06个百分点,而假阳性率(FPR)降低了1.11个百分点。可见,EWVD细化了边权重的表示,并且提升了漏洞检测的综合性能。展开更多
The lack of existing solutions makes it really hard to understand formal specification languages since the application domain for representations is useful for the purpose of carrying out certain software engineering ...The lack of existing solutions makes it really hard to understand formal specification languages since the application domain for representations is useful for the purpose of carrying out certain software engineering operations such as slicing and the computation of program metrics.A Z specification dependence graph is presented in this letter. It draws on the strengths of a range of earlier works and adapts them, if necessary, to the Z language.展开更多
Program slice has many applications such as program debugging, testing, maintenance, and complexity measurement. A static slice consists of all statements in program P that may effect the value of variable v a...Program slice has many applications such as program debugging, testing, maintenance, and complexity measurement. A static slice consists of all statements in program P that may effect the value of variable v at some point p , and a dynamic slice consists only of statements that influence the value of variable occurrence for specific program inputs. In this paper, we concern the problem of dynamic slicing of object oriented programs which, to our knowledge, has not been addressed in the literatures. To solve this problem, we present the dynamic object oriented dependence graph (DODG)which is an arc classified digraph to explicitly represent various dynamic dependence between statement instances for a particular execution of an object oriented program. Based on the DODG, we present a two phase backward algorithm for computing a dynamic slice of an object oriented program.展开更多
An algorithm is proposed in this paper for solving two-dimensional bi-level linear programming problems without making a graph. Based on the classification of constraints, algorithm removes all redundant constraints, ...An algorithm is proposed in this paper for solving two-dimensional bi-level linear programming problems without making a graph. Based on the classification of constraints, algorithm removes all redundant constraints, which eliminate the possibility of cycling and the solution of the problem is reached in a finite number of steps. Example to illustrate the method is also included in the paper.展开更多
基金Project supported by the National Natural Science Foundation of China!(19771075)
文摘The basis graph \%G\% for a linear programming consists of all bases under pivot transformations. A degenerate optimal basis graph G * is a subgraph of \%G\% induced by all optimal bases at a degenerate optimal vertex x 0. In this paper, several conditions for the characterization of G * are presented.
文摘Let be an undirected graph. The maximum cycle packing problem in G then is to find a collection of edge-disjoint cycles C<sub>i</sup>in G such that s is maximum. In general, the maximum cycle packing problem is NP-hard. In this paper, it is shown for even graphs that if such a collection satisfies the condition that it minimizes the quantityon the set of all edge-disjoint cycle collections, then it is a maximum cycle packing. The paper shows that the determination of such a packing can be solved by a dynamic programming approach. For its solution, an-shortest path procedure on an appropriate acyclic networkis presented. It uses a particular monotonous node potential.
文摘随着软件在各个领域的广泛应用,软件漏洞呈不断增长的趋势,基于深度学习的软件漏洞检测方法得到广泛应用;然而,现有的图表示学习方法通常忽略了图中边对软件漏洞检测的影响,并且对边权重的表示过于粗糙。针对该问题,提出一种基于边权重的软件漏洞检测方法EWVD(Edge Weight for Vulnerability Detection)。首先,对源代码中的注释、自定义变量名和函数名进行清理和抽象表示;其次,经过对比分析后选择使用Sent2Vec进行嵌入表示;再次,利用连接结构、邻居节点的重要性和Jaccard相似性这3种度量方式,综合计算边权重,从而识别节点间的信息传递能力;最后,利用边权重提升模型对漏洞语句潜在关系的感知能力,从而判断图中边的重要性。实验结果表明,与7种漏洞检测基线方法中的最优基线VulCNN相比,EWVD的准确率提高了1.06个百分点,而假阳性率(FPR)降低了1.11个百分点。可见,EWVD细化了边权重的表示,并且提升了漏洞检测的综合性能。
文摘The lack of existing solutions makes it really hard to understand formal specification languages since the application domain for representations is useful for the purpose of carrying out certain software engineering operations such as slicing and the computation of program metrics.A Z specification dependence graph is presented in this letter. It draws on the strengths of a range of earlier works and adapts them, if necessary, to the Z language.
文摘Program slice has many applications such as program debugging, testing, maintenance, and complexity measurement. A static slice consists of all statements in program P that may effect the value of variable v at some point p , and a dynamic slice consists only of statements that influence the value of variable occurrence for specific program inputs. In this paper, we concern the problem of dynamic slicing of object oriented programs which, to our knowledge, has not been addressed in the literatures. To solve this problem, we present the dynamic object oriented dependence graph (DODG)which is an arc classified digraph to explicitly represent various dynamic dependence between statement instances for a particular execution of an object oriented program. Based on the DODG, we present a two phase backward algorithm for computing a dynamic slice of an object oriented program.
文摘An algorithm is proposed in this paper for solving two-dimensional bi-level linear programming problems without making a graph. Based on the classification of constraints, algorithm removes all redundant constraints, which eliminate the possibility of cycling and the solution of the problem is reached in a finite number of steps. Example to illustrate the method is also included in the paper.
