The problem of solving a linear programming is converted into that of solving an uncon-strained maximization problem in which the objective function is concave. Two algorithms areproposed. These two algorithms have ve...The problem of solving a linear programming is converted into that of solving an uncon-strained maximization problem in which the objective function is concave. Two algorithms areproposed. These two algorithms have very simple structure and can be implemented easily. Forany given precision, the algorithms will terminate in a finite number of steps.展开更多
Background equalization technique has been extensively studied in the field of fre quency spectrum analysis. It has been proved an effective method to improve line spectrum extraction. In a multi-beam digital sonar ...Background equalization technique has been extensively studied in the field of fre quency spectrum analysis. It has been proved an effective method to improve line spectrum extraction. In a multi-beam digital sonar system, the time/bearing display is the most im portant interface between signal processing module and console module. It has been proved that the system gain is often lost in the illterface between these two modules. Background equalization technique can improv the overall performance of the time/bearing display win dow. The result of post processing of multi-beam data is filtered each time before displayed in screen. It is shown that the algorithm of median value filtering combined with OTA (Order Truncate Average) method is an efficient technique to equalize the non-uniform, non-stationary background data. A variable length of window is adopted to match the different width of main lobe of beam patterns. The results of system simulation show that the algorithm described in this paper is efficient in the case that the background of multi-beam data is not uniform展开更多
For the question that fuzzy c-means(FCM)clustering algorithm has the disadvantages of being too sensitive to the initial cluster centers and easily trapped in local optima,this paper introduces a new metric norm in FC...For the question that fuzzy c-means(FCM)clustering algorithm has the disadvantages of being too sensitive to the initial cluster centers and easily trapped in local optima,this paper introduces a new metric norm in FCM and particle swarm optimization(PSO)clustering algorithm,and proposes a parallel optimization algorithm using an improved fuzzy c-means method combined with particle swarm optimization(AF-APSO).The experiment shows that the AF-APSO can avoid local optima,and get the best fitness and clustering performance significantly.展开更多
In order to improve the attack efficiency of the New FORK-256 function, an algorithm based on Grover's quantum search algorithm and birthday attack is proposed. In this algorithm, finding a collision for arbitrary...In order to improve the attack efficiency of the New FORK-256 function, an algorithm based on Grover's quantum search algorithm and birthday attack is proposed. In this algorithm, finding a collision for arbitrary hash function only needs O(2m/3) expected evaluations, where m is the size of hash space value. It is proved that the algorithm can obviously improve the attack efficiency for only needing O(2 74.7) expected evaluations, and this is more efficient than any known classical algorithm, and the consumed space of the algorithm equals the evaluation.展开更多
新型电力系统下,大量新能源电源及电力电子设备接入交流电网。发生母线区内故障时,受控制策略影响,故障电流幅值受控,角度受控,谐波含量高,母线比率差动保护的动作性能下降,因此文中提出一种适用于新型电力系统的母线比率差动保护改进...新型电力系统下,大量新能源电源及电力电子设备接入交流电网。发生母线区内故障时,受控制策略影响,故障电流幅值受控,角度受控,谐波含量高,母线比率差动保护的动作性能下降,因此文中提出一种适用于新型电力系统的母线比率差动保护改进算法。首先,介绍传统比率差动算法的基本原理,并分析新型电力系统下该算法存在的问题;然后,提出不受故障电流角差及谐波影响的母线比率差动保护改进算法,将相位存在差异的各支路电流相量映射到同一坐标系下,并进行差流和制动电流计算,分析母线比率差动保护改进算法在母线区内外故障及区外故障电流互感器(current transformer,CT)饱和时的动作性能,提出母线比率差动保护改进逻辑;最后,基于实时数字仿真(real time digital simulation,RTDS),对比传统比率差动保护和改进比率差动保护的动作性能,证明改进比率差动保护能够在不降低保护动作可靠性的前提下提高动作灵敏性。展开更多
文摘The problem of solving a linear programming is converted into that of solving an uncon-strained maximization problem in which the objective function is concave. Two algorithms areproposed. These two algorithms have very simple structure and can be implemented easily. Forany given precision, the algorithms will terminate in a finite number of steps.
文摘Background equalization technique has been extensively studied in the field of fre quency spectrum analysis. It has been proved an effective method to improve line spectrum extraction. In a multi-beam digital sonar system, the time/bearing display is the most im portant interface between signal processing module and console module. It has been proved that the system gain is often lost in the illterface between these two modules. Background equalization technique can improv the overall performance of the time/bearing display win dow. The result of post processing of multi-beam data is filtered each time before displayed in screen. It is shown that the algorithm of median value filtering combined with OTA (Order Truncate Average) method is an efficient technique to equalize the non-uniform, non-stationary background data. A variable length of window is adopted to match the different width of main lobe of beam patterns. The results of system simulation show that the algorithm described in this paper is efficient in the case that the background of multi-beam data is not uniform
基金the China Agriculture Research System(No.CARS-49)Jiangsu College of Humanities and Social Sciences Outside Campus Research Base & Chinese Development of Strategic Research Base for Internet of Things
文摘For the question that fuzzy c-means(FCM)clustering algorithm has the disadvantages of being too sensitive to the initial cluster centers and easily trapped in local optima,this paper introduces a new metric norm in FCM and particle swarm optimization(PSO)clustering algorithm,and proposes a parallel optimization algorithm using an improved fuzzy c-means method combined with particle swarm optimization(AF-APSO).The experiment shows that the AF-APSO can avoid local optima,and get the best fitness and clustering performance significantly.
基金Supported by the National High Technology Research and Development Program(No.2011AA010803)the National Natural Science Foundation of China(No.U1204602)
文摘In order to improve the attack efficiency of the New FORK-256 function, an algorithm based on Grover's quantum search algorithm and birthday attack is proposed. In this algorithm, finding a collision for arbitrary hash function only needs O(2m/3) expected evaluations, where m is the size of hash space value. It is proved that the algorithm can obviously improve the attack efficiency for only needing O(2 74.7) expected evaluations, and this is more efficient than any known classical algorithm, and the consumed space of the algorithm equals the evaluation.
文摘新型电力系统下,大量新能源电源及电力电子设备接入交流电网。发生母线区内故障时,受控制策略影响,故障电流幅值受控,角度受控,谐波含量高,母线比率差动保护的动作性能下降,因此文中提出一种适用于新型电力系统的母线比率差动保护改进算法。首先,介绍传统比率差动算法的基本原理,并分析新型电力系统下该算法存在的问题;然后,提出不受故障电流角差及谐波影响的母线比率差动保护改进算法,将相位存在差异的各支路电流相量映射到同一坐标系下,并进行差流和制动电流计算,分析母线比率差动保护改进算法在母线区内外故障及区外故障电流互感器(current transformer,CT)饱和时的动作性能,提出母线比率差动保护改进逻辑;最后,基于实时数字仿真(real time digital simulation,RTDS),对比传统比率差动保护和改进比率差动保护的动作性能,证明改进比率差动保护能够在不降低保护动作可靠性的前提下提高动作灵敏性。
