Network virtualization is known as a promising technology to tackle the ossification of current Internet and will play an important role in the future network area. Virtual network embedding(VNE) is a key issue in net...Network virtualization is known as a promising technology to tackle the ossification of current Internet and will play an important role in the future network area. Virtual network embedding(VNE) is a key issue in network virtualization. VNE is NP-hard and former VNE algorithms are mostly heuristic in the literature.VNE exact algorithms have been developed in recent years. However, the constraints of exact VNE are only node capacity and link bandwidth.Based on these, this paper presents an exact VNE algorithm, ILP-LC, which is based on Integer Linear Programming(ILP), for embedding virtual network request with location constraints. This novel algorithm is aiming at mapping virtual network request(VNR) successfully as many as possible and consuming less substrate resources.The topology of each VNR is randomly generated by Waxman model. Simulation results show that the proposed ILP-LC algorithm outperforms the typical heuristic algorithms in terms of the VNR acceptance ratio, at least 15%.展开更多
A new heuristic algorithm is proposed for solving general integer linear programming problems. In the algorithm, the objective function hyperplane is used as a cutting plane, and then by introducing a special set of a...A new heuristic algorithm is proposed for solving general integer linear programming problems. In the algorithm, the objective function hyperplane is used as a cutting plane, and then by introducing a special set of assistant sets, an efficient heuristic search for the solution to the integer linear program is carried out in the sets on the objective function hyperplane. A simple numerical example shows that the algorithm is efficient for some problems, and therefore, of practical interest.展开更多
一方面,为提高主动配电网供电恢复过程中的孤岛运行模式的供电可靠性,另一方面,为充分协调调压设备和网络重构以提高电能质量,本文综合考虑调压设备、微电网、网络重构等作用,建立基于混合整数线性规划(mixed integer linear programmin...一方面,为提高主动配电网供电恢复过程中的孤岛运行模式的供电可靠性,另一方面,为充分协调调压设备和网络重构以提高电能质量,本文综合考虑调压设备、微电网、网络重构等作用,建立基于混合整数线性规划(mixed integer linear programming,MILP)模型的主动配电网供电恢复模型。该模型以开关操作的动作成本、电压调节设备的调节成本、失负荷成本组成的总成本为目标,以线性化潮流约束、DG模型、ZIP负荷模型、电压调节设备模型等为约束条件,建立了主动配电网供电恢复优化的MILP模型。在53节点配电系统的仿真结果验证了电压调节设备控制和微电网对配电网供电恢复的改善作用。展开更多
基金supported by the National Basic Research Program of China(973 Program)under Grant 2013CB329005
文摘Network virtualization is known as a promising technology to tackle the ossification of current Internet and will play an important role in the future network area. Virtual network embedding(VNE) is a key issue in network virtualization. VNE is NP-hard and former VNE algorithms are mostly heuristic in the literature.VNE exact algorithms have been developed in recent years. However, the constraints of exact VNE are only node capacity and link bandwidth.Based on these, this paper presents an exact VNE algorithm, ILP-LC, which is based on Integer Linear Programming(ILP), for embedding virtual network request with location constraints. This novel algorithm is aiming at mapping virtual network request(VNR) successfully as many as possible and consuming less substrate resources.The topology of each VNR is randomly generated by Waxman model. Simulation results show that the proposed ILP-LC algorithm outperforms the typical heuristic algorithms in terms of the VNR acceptance ratio, at least 15%.
文摘A new heuristic algorithm is proposed for solving general integer linear programming problems. In the algorithm, the objective function hyperplane is used as a cutting plane, and then by introducing a special set of assistant sets, an efficient heuristic search for the solution to the integer linear program is carried out in the sets on the objective function hyperplane. A simple numerical example shows that the algorithm is efficient for some problems, and therefore, of practical interest.
文摘一方面,为提高主动配电网供电恢复过程中的孤岛运行模式的供电可靠性,另一方面,为充分协调调压设备和网络重构以提高电能质量,本文综合考虑调压设备、微电网、网络重构等作用,建立基于混合整数线性规划(mixed integer linear programming,MILP)模型的主动配电网供电恢复模型。该模型以开关操作的动作成本、电压调节设备的调节成本、失负荷成本组成的总成本为目标,以线性化潮流约束、DG模型、ZIP负荷模型、电压调节设备模型等为约束条件,建立了主动配电网供电恢复优化的MILP模型。在53节点配电系统的仿真结果验证了电压调节设备控制和微电网对配电网供电恢复的改善作用。
