Chinese Postman Problem is an unsettled graphic problem. It was approached seldom by evolutionary computation. Now we use genetic algorithm to solve Chinese Postman Problem in undirected graph and get good results. It...Chinese Postman Problem is an unsettled graphic problem. It was approached seldom by evolutionary computation. Now we use genetic algorithm to solve Chinese Postman Problem in undirected graph and get good results. It could be extended to solve Chinese postman problem in directed graph. We make these efforts for exploring in optimizing the mixed Chinese postman problem.展开更多
If we restrict the postman to traversing each edge at most twice in the windypostman problem (WPP), we will get a new problem: 2WPP. An approximation algorithmhas been posed by M. Guan for the WPP. In the present pape...If we restrict the postman to traversing each edge at most twice in the windypostman problem (WPP), we will get a new problem: 2WPP. An approximation algorithmhas been posed by M. Guan for the WPP. In the present paper, we improve the estimatederror given by M. Guan and show that we can estimate the error for the 2WPP by findinga minimum cost circulation. We also pose a new sufficient condition for the equivalencebetween WPP and 2WPP, which can be checked in polynomial time steps.展开更多
时间依赖网络相比传统网络模型有更广泛的应用领域,比如公交网络和通信网络都可以抽象成为时间依赖的网络模型。当模型中弧的访问代价为时间依赖的变量时,中国邮路问题的求解将变得非常困难。首先分析了传统的中国邮路问题求解算法,如...时间依赖网络相比传统网络模型有更广泛的应用领域,比如公交网络和通信网络都可以抽象成为时间依赖的网络模型。当模型中弧的访问代价为时间依赖的变量时,中国邮路问题的求解将变得非常困难。首先分析了传统的中国邮路问题求解算法,如奇偶图上作业法和Edmonds&Johnson算法,以及不能有效求解时间依赖中国邮路问题的根本原因;其次给出了一般时变无向中国邮路问题的特性,并在此基础上设计了该问题的分支限界最优化算法;然后针对FIFO(First In First Out)这一类特殊时变网络,设计了新的剪枝条件,从而得到了更有效求解FIFO网络的时变无向中国邮路问题的分支限界最优化算法;最后对算法进行了实验,算法实验结果正确。展开更多
基金Supported by the National Natural Science Foundation of China(60133010,70071042)
文摘Chinese Postman Problem is an unsettled graphic problem. It was approached seldom by evolutionary computation. Now we use genetic algorithm to solve Chinese Postman Problem in undirected graph and get good results. It could be extended to solve Chinese postman problem in directed graph. We make these efforts for exploring in optimizing the mixed Chinese postman problem.
文摘If we restrict the postman to traversing each edge at most twice in the windypostman problem (WPP), we will get a new problem: 2WPP. An approximation algorithmhas been posed by M. Guan for the WPP. In the present paper, we improve the estimatederror given by M. Guan and show that we can estimate the error for the 2WPP by findinga minimum cost circulation. We also pose a new sufficient condition for the equivalencebetween WPP and 2WPP, which can be checked in polynomial time steps.
文摘时间依赖网络相比传统网络模型有更广泛的应用领域,比如公交网络和通信网络都可以抽象成为时间依赖的网络模型。当模型中弧的访问代价为时间依赖的变量时,中国邮路问题的求解将变得非常困难。首先分析了传统的中国邮路问题求解算法,如奇偶图上作业法和Edmonds&Johnson算法,以及不能有效求解时间依赖中国邮路问题的根本原因;其次给出了一般时变无向中国邮路问题的特性,并在此基础上设计了该问题的分支限界最优化算法;然后针对FIFO(First In First Out)这一类特殊时变网络,设计了新的剪枝条件,从而得到了更有效求解FIFO网络的时变无向中国邮路问题的分支限界最优化算法;最后对算法进行了实验,算法实验结果正确。
