Based on the deficiency of time convergence and variability of Web services selection for services composition supporting cross-enterprises collaboration,an algorithm QCDSS(QoS constraints of dynamic Web services sele...Based on the deficiency of time convergence and variability of Web services selection for services composition supporting cross-enterprises collaboration,an algorithm QCDSS(QoS constraints of dynamic Web services selection)to resolve dynamic Web services selection with QoS global optimal path,was proposed.The essence of the algorithm was that the problem of dynamic Web services selection with QoS global optimal path was transformed into a multi-objective services composition optimization problem with QoS constraints.The operations of the cross and mutation in genetic algorithm were brought into PSOA(particle swarm optimization algorithm),forming an improved algorithm(IPSOA)to solve the QoS global optimal problem.Theoretical analysis and experimental results indicate that the algorithm can better satisfy the time convergence requirement for Web services composition supporting cross-enterprises collaboration than the traditional algorithms.展开更多
As a core component of the network,web applications have become one of the preferred targets for attackers because the static configuration of web applications simplifies the exploitation of vulnerabilities by attacke...As a core component of the network,web applications have become one of the preferred targets for attackers because the static configuration of web applications simplifies the exploitation of vulnerabilities by attackers.Although the moving target defense(MTD)has been proposed to increase the attack difficulty for the attackers,there is no solo approach can cope with different attacks;in addition,it is impossible to implement all these approaches simultaneously due to the resource limitation.Thus,the selection of an optimal defense strategy based on MTD has become the focus of research.In general,the confrontation of two players in the security domain is viewed as a stochastic game,and the reward matrices are known to both players.However,in a real security confrontation,this scenario represents an incomplete information game.Each player can only observe the actions performed by the opponent,and the observed actions are not completely accurate.To accurately describe the attacker’s reward function to reach the Nash equilibrium,this work simulated and updated the strategy selection distribution of the attacker by observing and investigating the strategy selection history of the attacker.Next,the possible rewards of the attacker in each confrontation via the observation matrix were corrected.On this basis,the Nash-Q learning algorithm with reward quantification was proposed to select the optimal strategy.Moreover,the performances of the Minimax-Q learning algorithm and Naive-Q learning algorithm were compared and analyzed in the MTD environment.Finally,the experimental results showed that the strategy selection algorithm can enable defenders to select a more reasonable defensive strategy and achieve the maximum possible reward.展开更多
Obtaining the location of an unknown node accurately is a key problem of a locating service under a ubiquitous computing environment.The paper proposes and proves three theorems of location reference node placement ac...Obtaining the location of an unknown node accurately is a key problem of a locating service under a ubiquitous computing environment.The paper proposes and proves three theorems of location reference node placement according to the analysis of the location error produced during location using a polygon location method and three important characteristics of chaos dynamics.Based on the three theorems,the location reference node selection(LRNS)algorithm is proposed by improving on the traditional polygon location algorithm.The simulation results indicate that the reference node placement theorems and the LRNS algo-rithm can meet the requirements of a ubiquitous terminal’s real-time location and possess a preferable precision in location.展开更多
Web服务作为一种新型的Web应用模式,近年来得到了迅速的发展.如何动态地把现存的各种Web服务整合起来以形成新的、满足不同用户需求的、增值的复杂服务已成为新的应用需求和研究热点.针对现有服务聚合中服务选择技术的不足,提出了一种...Web服务作为一种新型的Web应用模式,近年来得到了迅速的发展.如何动态地把现存的各种Web服务整合起来以形成新的、满足不同用户需求的、增值的复杂服务已成为新的应用需求和研究热点.针对现有服务聚合中服务选择技术的不足,提出了一种解决服务聚合中服务动态选择QoS全局最优化问题的实现算法GODSS(global optimal of dynamic Web services selection).算法的主要思想是把服务动态选择全局最优化问题转化为一个带QoS约束的多目标服务组合优化问题,利用多目标遗传算法的智能优化原理,通过同时优化多个目标函数,最终产生一组满足约束条件的Pareto优化服务聚合流程集.理论分析和实验结果说明了算法的可行性和有效性.展开更多
基金Project(70631004)supported by the Key Project of the National Natural Science Foundation of ChinaProject(20080440988)supported by the Postdoctoral Science Foundation of China+1 种基金Project(09JJ4030)supported by the Natural Science Foundation of Hunan Province,ChinaProject supported by the Postdoctoral Science Foundation of Central South University,China
文摘Based on the deficiency of time convergence and variability of Web services selection for services composition supporting cross-enterprises collaboration,an algorithm QCDSS(QoS constraints of dynamic Web services selection)to resolve dynamic Web services selection with QoS global optimal path,was proposed.The essence of the algorithm was that the problem of dynamic Web services selection with QoS global optimal path was transformed into a multi-objective services composition optimization problem with QoS constraints.The operations of the cross and mutation in genetic algorithm were brought into PSOA(particle swarm optimization algorithm),forming an improved algorithm(IPSOA)to solve the QoS global optimal problem.Theoretical analysis and experimental results indicate that the algorithm can better satisfy the time convergence requirement for Web services composition supporting cross-enterprises collaboration than the traditional algorithms.
基金This paper is supported by the National Key R&D Program of China(2017YFB0802703)the National Nature Science Foundation of China(61602052).
文摘As a core component of the network,web applications have become one of the preferred targets for attackers because the static configuration of web applications simplifies the exploitation of vulnerabilities by attackers.Although the moving target defense(MTD)has been proposed to increase the attack difficulty for the attackers,there is no solo approach can cope with different attacks;in addition,it is impossible to implement all these approaches simultaneously due to the resource limitation.Thus,the selection of an optimal defense strategy based on MTD has become the focus of research.In general,the confrontation of two players in the security domain is viewed as a stochastic game,and the reward matrices are known to both players.However,in a real security confrontation,this scenario represents an incomplete information game.Each player can only observe the actions performed by the opponent,and the observed actions are not completely accurate.To accurately describe the attacker’s reward function to reach the Nash equilibrium,this work simulated and updated the strategy selection distribution of the attacker by observing and investigating the strategy selection history of the attacker.Next,the possible rewards of the attacker in each confrontation via the observation matrix were corrected.On this basis,the Nash-Q learning algorithm with reward quantification was proposed to select the optimal strategy.Moreover,the performances of the Minimax-Q learning algorithm and Naive-Q learning algorithm were compared and analyzed in the MTD environment.Finally,the experimental results showed that the strategy selection algorithm can enable defenders to select a more reasonable defensive strategy and achieve the maximum possible reward.
基金supported by the National Natural Science Foundation of China(Grant No.69873007)the Hi-Tech Research and Development Program of China(No.2001AA415320).
文摘Obtaining the location of an unknown node accurately is a key problem of a locating service under a ubiquitous computing environment.The paper proposes and proves three theorems of location reference node placement according to the analysis of the location error produced during location using a polygon location method and three important characteristics of chaos dynamics.Based on the three theorems,the location reference node selection(LRNS)algorithm is proposed by improving on the traditional polygon location algorithm.The simulation results indicate that the reference node placement theorems and the LRNS algo-rithm can meet the requirements of a ubiquitous terminal’s real-time location and possess a preferable precision in location.
基金Supported by the National HighTech Research and Development Plan of China under Grant Nos.2002AA1340102002AA1340202003AA135110(国家高技术研究发展计划(863))
文摘Web服务作为一种新型的Web应用模式,近年来得到了迅速的发展.如何动态地把现存的各种Web服务整合起来以形成新的、满足不同用户需求的、增值的复杂服务已成为新的应用需求和研究热点.针对现有服务聚合中服务选择技术的不足,提出了一种解决服务聚合中服务动态选择QoS全局最优化问题的实现算法GODSS(global optimal of dynamic Web services selection).算法的主要思想是把服务动态选择全局最优化问题转化为一个带QoS约束的多目标服务组合优化问题,利用多目标遗传算法的智能优化原理,通过同时优化多个目标函数,最终产生一组满足约束条件的Pareto优化服务聚合流程集.理论分析和实验结果说明了算法的可行性和有效性.
