A novel space-borne antenna adaptive anti-jamming method based on the genetic algorithm （GA）, which is combined with gradient-like reproduction operators is presented, to search for the best weight for pattern synth...A novel space-borne antenna adaptive anti-jamming method based on the genetic algorithm （GA）, which is combined with gradient-like reproduction operators is presented, to search for the best weight for pattern synthesis in radio frequency （RF）. Combined, the GA＇s the capability of the whole searching is, but not limited by selection of the initial parameter, with the gradient algorithm＇s advantage of fast searching. The proposed method requires a smaller sized initial population and lower computational complexity. Therefore, it is flexible to implement this method in the real-time systems. By using the proposed algorithm, the designer can efficiently control both main-lobe shaping and side-lobe level. Simulation results based on the spot survey data show that the algorithm proposed is efficient and feasible.展开更多
Let C be a nonempty closed convex subset of a 2-uniformly convex and uniformly smooth Banach space E and {An}n∈N be a family of monotone and Lipschitz continuos mappings of C into E＊. In this article, we consider th...Let C be a nonempty closed convex subset of a 2-uniformly convex and uniformly smooth Banach space E and {An}n∈N be a family of monotone and Lipschitz continuos mappings of C into E＊. In this article, we consider the improved gradient method by the hybrid method in mathematical programming [i0] for solving the variational inequality problem for {AN} and prove strong convergence theorems. And we get several results which improve the well-known results in a real 2-uniformly convex and uniformly smooth Banach space and a real Hilbert space.展开更多
为了更好地设计高压直流(high voltage direct current,HVDC)交联聚乙烯(crosslinked polyethyline,XLPE)绝缘海底电缆,加快高压直流海底电缆绝缘国产化进程,结合电缆绝缘电导率试验方法测定某高压直流海底电缆XLPE绝缘材料在不同温度...为了更好地设计高压直流(high voltage direct current,HVDC)交联聚乙烯(crosslinked polyethyline,XLPE)绝缘海底电缆,加快高压直流海底电缆绝缘国产化进程,结合电缆绝缘电导率试验方法测定某高压直流海底电缆XLPE绝缘材料在不同温度及不同电场强度下的电导率;利用COMSOL多物理场仿真软件,采用分步式耦合分析方法,在相同敷设条件、不同负载电流下,对高压直流海底电缆绝缘内部的温度场、电场强度及空间电荷分布情况进行表征。仿真结果表明:采用分步式耦合分析方法可大幅减少模型求解时间,提升计算效率;在正常工作条件下,直流海底电缆绝缘内部会产生温度梯度和电场强度梯度,导致电导率发生变化,并进一步影响绝缘内部电场强度的分布;在电缆线芯的负载电流增大至一定程度时,出现场强反转现象;在绝缘内、外表面均会产生空间电荷积聚现象。文中仿真结果可为高压直流海底电缆的结构设计和国产绝缘材料开发提供理论依据和参考。展开更多
基金the National Natural Science Foundation of China (60502045).
文摘A novel space-borne antenna adaptive anti-jamming method based on the genetic algorithm （GA）, which is combined with gradient-like reproduction operators is presented, to search for the best weight for pattern synthesis in radio frequency （RF）. Combined, the GA＇s the capability of the whole searching is, but not limited by selection of the initial parameter, with the gradient algorithm＇s advantage of fast searching. The proposed method requires a smaller sized initial population and lower computational complexity. Therefore, it is flexible to implement this method in the real-time systems. By using the proposed algorithm, the designer can efficiently control both main-lobe shaping and side-lobe level. Simulation results based on the spot survey data show that the algorithm proposed is efficient and feasible.
文摘Let C be a nonempty closed convex subset of a 2-uniformly convex and uniformly smooth Banach space E and {An}n∈N be a family of monotone and Lipschitz continuos mappings of C into E＊. In this article, we consider the improved gradient method by the hybrid method in mathematical programming [i0] for solving the variational inequality problem for {AN} and prove strong convergence theorems. And we get several results which improve the well-known results in a real 2-uniformly convex and uniformly smooth Banach space and a real Hilbert space.
文摘为了更好地设计高压直流(high voltage direct current,HVDC)交联聚乙烯(crosslinked polyethyline,XLPE)绝缘海底电缆,加快高压直流海底电缆绝缘国产化进程,结合电缆绝缘电导率试验方法测定某高压直流海底电缆XLPE绝缘材料在不同温度及不同电场强度下的电导率;利用COMSOL多物理场仿真软件,采用分步式耦合分析方法,在相同敷设条件、不同负载电流下,对高压直流海底电缆绝缘内部的温度场、电场强度及空间电荷分布情况进行表征。仿真结果表明:采用分步式耦合分析方法可大幅减少模型求解时间,提升计算效率;在正常工作条件下,直流海底电缆绝缘内部会产生温度梯度和电场强度梯度,导致电导率发生变化,并进一步影响绝缘内部电场强度的分布;在电缆线芯的负载电流增大至一定程度时,出现场强反转现象;在绝缘内、外表面均会产生空间电荷积聚现象。文中仿真结果可为高压直流海底电缆的结构设计和国产绝缘材料开发提供理论依据和参考。
