Ants of artificial colony are able to generate good solutions to the famous traveling salesman problem (TSP). We propose an artificial ants algorithm for solving the minimum ratio TSP, which is more general than the s...Ants of artificial colony are able to generate good solutions to the famous traveling salesman problem (TSP). We propose an artificial ants algorithm for solving the minimum ratio TSP, which is more general than the standard TSP in combinatorial optimization area. In the minimum ratio TSP, another criterion concerning each edge is added, that is, the traveling salesman can have a benefit if he travels from one city to another. The objective is to minimize the ratio between total costs or distances and total benefits. The idea of this type of optimization is in some sense quite similar to that of traditional cost-benefit analysis in management science. Computational results substantiate the solution quality and efficiency of the algorithm.展开更多
Explaining the causes of infeasibility of Boolean formulas has many practical applications in electronic design automation and formal verification of hardware.Furthermore,a minimum explanation of infeasibility that ex...Explaining the causes of infeasibility of Boolean formulas has many practical applications in electronic design automation and formal verification of hardware.Furthermore,a minimum explanation of infeasibility that excludes all irrelevant information is generally of interest.A smallest-cardinality unsatisfiable subset called a minimum unsatisfiable core can provide a succinct explanation of infea-sibility and is valuable for applications.However,little attention has been concentrated on extraction of minimum unsatisfiable core.In this paper,the relationship between maximal satisfiability and mini-mum unsatisfiability is presented and proved,then an efficient ant colony algorithm is proposed to derive an exact or nearly exact minimum unsatisfiable core based on the relationship.Finally,ex-perimental results on practical benchmarks compared with the best known approach are reported,and the results show that the ant colony algorithm strongly outperforms the best previous algorithm.展开更多
该文研究了基于正交时频空间(orthogonal time frequency space, OTFS)调制的去蜂窝大规模多输入多输出(massive multiple-input multiple-output, mMIMO)系统上行链路通信中的和速率优化问题,提出一种蚁群递归搜索机制。该机制首先采...该文研究了基于正交时频空间(orthogonal time frequency space, OTFS)调制的去蜂窝大规模多输入多输出(massive multiple-input multiple-output, mMIMO)系统上行链路通信中的和速率优化问题,提出一种蚁群递归搜索机制。该机制首先采用最小割分组算法实现用户分组,然后使用蚁群算法进行递归优化求解。仿真结果表明,通过运用该机制进行功率控制,其性能相比于未分组的m MIMO-OTFS系统和m MIMO-正交频分复用(orthogonal frequency division multiplexing, OFDM)系统更好。此外,移动速度对系统用户上行可达速率性能的影响研究结果表明,mMIMO-OTFS系统与mMIMO-OFDM系统的和速率性能差距随移动速度增长呈递增状态。展开更多
Based on the ant system methodology,this paper offers an algorithm for the degree constrained minimum spanning tree problem.Compared with some other algorithms, numerical examples are tested which give promising resul...Based on the ant system methodology,this paper offers an algorithm for the degree constrained minimum spanning tree problem.Compared with some other algorithms, numerical examples are tested which give promising results and useful conclusions.展开更多
为获得发电机励磁系统准确的模型参数,对BPA(bonneville power administration)软件中励磁系统典型仿真模型进行深入分析,得到模型参数与励磁系统大、小阶跃响应特性的关联关系。结合实际情况,对需辨识参数进行筛选,对参数取值范围进行...为获得发电机励磁系统准确的模型参数,对BPA(bonneville power administration)软件中励磁系统典型仿真模型进行深入分析,得到模型参数与励磁系统大、小阶跃响应特性的关联关系。结合实际情况,对需辨识参数进行筛选,对参数取值范围进行限制。采用最大-最小蚁群算法对参数进行辨识,先求得影响发电机空载电压小干扰阶跃响应特性的主要参数,再得到影响发电机空载电压大干扰阶跃响应特性的主要参数。BPA计算得到的辨识模型仿真曲线与实测数据吻合良好,仿真结果表明了辨识方法的有效性。展开更多
基金This project was supported by the Shanghai Education Development Foundation (No.2000SG30).
文摘Ants of artificial colony are able to generate good solutions to the famous traveling salesman problem (TSP). We propose an artificial ants algorithm for solving the minimum ratio TSP, which is more general than the standard TSP in combinatorial optimization area. In the minimum ratio TSP, another criterion concerning each edge is added, that is, the traveling salesman can have a benefit if he travels from one city to another. The objective is to minimize the ratio between total costs or distances and total benefits. The idea of this type of optimization is in some sense quite similar to that of traditional cost-benefit analysis in management science. Computational results substantiate the solution quality and efficiency of the algorithm.
基金the National Natural Science Foundation of China (No.60603088)
文摘Explaining the causes of infeasibility of Boolean formulas has many practical applications in electronic design automation and formal verification of hardware.Furthermore,a minimum explanation of infeasibility that excludes all irrelevant information is generally of interest.A smallest-cardinality unsatisfiable subset called a minimum unsatisfiable core can provide a succinct explanation of infea-sibility and is valuable for applications.However,little attention has been concentrated on extraction of minimum unsatisfiable core.In this paper,the relationship between maximal satisfiability and mini-mum unsatisfiability is presented and proved,then an efficient ant colony algorithm is proposed to derive an exact or nearly exact minimum unsatisfiable core based on the relationship.Finally,ex-perimental results on practical benchmarks compared with the best known approach are reported,and the results show that the ant colony algorithm strongly outperforms the best previous algorithm.
文摘该文研究了基于正交时频空间(orthogonal time frequency space, OTFS)调制的去蜂窝大规模多输入多输出(massive multiple-input multiple-output, mMIMO)系统上行链路通信中的和速率优化问题,提出一种蚁群递归搜索机制。该机制首先采用最小割分组算法实现用户分组,然后使用蚁群算法进行递归优化求解。仿真结果表明,通过运用该机制进行功率控制,其性能相比于未分组的m MIMO-OTFS系统和m MIMO-正交频分复用(orthogonal frequency division multiplexing, OFDM)系统更好。此外,移动速度对系统用户上行可达速率性能的影响研究结果表明,mMIMO-OTFS系统与mMIMO-OFDM系统的和速率性能差距随移动速度增长呈递增状态。
文摘Based on the ant system methodology,this paper offers an algorithm for the degree constrained minimum spanning tree problem.Compared with some other algorithms, numerical examples are tested which give promising results and useful conclusions.
文摘为获得发电机励磁系统准确的模型参数,对BPA(bonneville power administration)软件中励磁系统典型仿真模型进行深入分析,得到模型参数与励磁系统大、小阶跃响应特性的关联关系。结合实际情况,对需辨识参数进行筛选,对参数取值范围进行限制。采用最大-最小蚁群算法对参数进行辨识,先求得影响发电机空载电压小干扰阶跃响应特性的主要参数,再得到影响发电机空载电压大干扰阶跃响应特性的主要参数。BPA计算得到的辨识模型仿真曲线与实测数据吻合良好,仿真结果表明了辨识方法的有效性。
