This research paper represents a numerical approximation to non-linear two-dimensional reaction diffusion equation from population genetics. Since various initial and boundary value problems exist in two-dimensional r...This research paper represents a numerical approximation to non-linear two-dimensional reaction diffusion equation from population genetics. Since various initial and boundary value problems exist in two-dimensional reaction-diffusion, phenomena are studied numerically by different numerical methods, here we use finite difference schemes to approximate the solution. Accuracy is studied in term of L2, L∞ and relative error norms by random selected grids along time levels for comparison with exact results. The test example demonstrates the accuracy, efficiency and versatility of the proposed schemes. It is shown that the numerical schemes give better solutions. Moreover, the schemes can be easily applied to a wide class of higher dimension nonlinear reaction diffusion equations with a little modification.展开更多
考虑配电网不同区域之间的差异性与耦合性,提出一种基于区域解耦的时空双尺度电动汽车优化调度方法。首先,综合考虑分区的电气特性、生产生活特性以及电动汽车出行特性,提出一种新的基于图论法的配电网络分区方法;接着,提出一种时空双...考虑配电网不同区域之间的差异性与耦合性,提出一种基于区域解耦的时空双尺度电动汽车优化调度方法。首先,综合考虑分区的电气特性、生产生活特性以及电动汽车出行特性,提出一种新的基于图论法的配电网络分区方法;接着,提出一种时空双尺度的电动汽车分层调度方法。上层为时间尺度的调度,以最小化系统峰谷差和负荷方差为目标,通过优化调度得到配电网各时段的电动汽车最优充放电数目;下层为空间尺度的调度,结合上层优化结果,针对不同区域间电动汽车负荷的差异性,分别在商业区构建考虑充电站拥挤度的动态电价调度模型,在居民区和办公区构建考虑用户意愿指数的动态电价调度模型。最后,针对区域间复杂耦合性造成优化模型难以求解的问题,建立基于信赖域的改进乘子交替方向–序列二次规划(alternating direction method of multipliers-successive quadratic programming,ADMM-SQP)算法,并对各个区域的子模型解耦后并行求解。为验证所提方法的有效性,基于IEEE33节点构建仿真模型,结果表明,所提优化方法能够实现多个区域电动汽车的协调优化调度。展开更多
To achieve robust communication in high mobility scenarios,an iterative equalization algorithm based on alternating minimization(AM)is proposed for the orthogonal time frequency space(OTFS)system.The algorithm approxi...To achieve robust communication in high mobility scenarios,an iterative equalization algorithm based on alternating minimization(AM)is proposed for the orthogonal time frequency space(OTFS)system.The algorithm approximates the equalization problem to a convex function optimization problem in the real-valued domain and solves the problem iteratively using the AM algorithm.In the iterative process,the complexity of the proposed algorithm is reduced further based on the study of the cyclic structure and sparse property of the OTFS channel matrix in the delay-Doppler(DD)domain.The new method for OTFS is simulated and verified in a high-speed mobile scenario and the results show that the proposed equalization algorithm has excellent bit error rate performance with low complexity.展开更多
文摘This research paper represents a numerical approximation to non-linear two-dimensional reaction diffusion equation from population genetics. Since various initial and boundary value problems exist in two-dimensional reaction-diffusion, phenomena are studied numerically by different numerical methods, here we use finite difference schemes to approximate the solution. Accuracy is studied in term of L2, L∞ and relative error norms by random selected grids along time levels for comparison with exact results. The test example demonstrates the accuracy, efficiency and versatility of the proposed schemes. It is shown that the numerical schemes give better solutions. Moreover, the schemes can be easily applied to a wide class of higher dimension nonlinear reaction diffusion equations with a little modification.
文摘考虑配电网不同区域之间的差异性与耦合性,提出一种基于区域解耦的时空双尺度电动汽车优化调度方法。首先,综合考虑分区的电气特性、生产生活特性以及电动汽车出行特性,提出一种新的基于图论法的配电网络分区方法;接着,提出一种时空双尺度的电动汽车分层调度方法。上层为时间尺度的调度,以最小化系统峰谷差和负荷方差为目标,通过优化调度得到配电网各时段的电动汽车最优充放电数目;下层为空间尺度的调度,结合上层优化结果,针对不同区域间电动汽车负荷的差异性,分别在商业区构建考虑充电站拥挤度的动态电价调度模型,在居民区和办公区构建考虑用户意愿指数的动态电价调度模型。最后,针对区域间复杂耦合性造成优化模型难以求解的问题,建立基于信赖域的改进乘子交替方向–序列二次规划(alternating direction method of multipliers-successive quadratic programming,ADMM-SQP)算法,并对各个区域的子模型解耦后并行求解。为验证所提方法的有效性,基于IEEE33节点构建仿真模型,结果表明,所提优化方法能够实现多个区域电动汽车的协调优化调度。
基金supported by the 54th Research Institute of China E lectronics Technology Group Corporation(SKX212010007)。
文摘To achieve robust communication in high mobility scenarios,an iterative equalization algorithm based on alternating minimization(AM)is proposed for the orthogonal time frequency space(OTFS)system.The algorithm approximates the equalization problem to a convex function optimization problem in the real-valued domain and solves the problem iteratively using the AM algorithm.In the iterative process,the complexity of the proposed algorithm is reduced further based on the study of the cyclic structure and sparse property of the OTFS channel matrix in the delay-Doppler(DD)domain.The new method for OTFS is simulated and verified in a high-speed mobile scenario and the results show that the proposed equalization algorithm has excellent bit error rate performance with low complexity.
