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基于K-shell的复杂网络簇生长维数研究 被引量:1
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作者 张耀波 张胜 +1 位作者 王雨萱 熊聪源 《复杂系统与复杂性科学》 北大核心 2025年第1期11-17,共7页
传统簇生长法时间复杂度高、对分形标度关系刻画不够精准,且关键节点在控制网络结构和功能方面具有重要作用。为选择具有代表性的节点来分析网络自相似分形问题,提出一种基于K-shell的复杂网络簇生长法,通过K-shell分解和节点信息熵选... 传统簇生长法时间复杂度高、对分形标度关系刻画不够精准,且关键节点在控制网络结构和功能方面具有重要作用。为选择具有代表性的节点来分析网络自相似分形问题,提出一种基于K-shell的复杂网络簇生长法,通过K-shell分解和节点信息熵选取核心层最具影响力节点作为簇生长法的种子节点计算网络的分形维数。实验结果表明所提方法对网络的分形性质刻画得更加细致,能够计算出更加准确的分形维数。 展开更多
关键词 复杂网络 分形 k-shell 分形维数 簇生长法
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Research on Euclidean Algorithm and Reection on Its Teaching
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作者 ZHANG Shaohua 《应用数学》 北大核心 2025年第1期308-310,共3页
In this paper,we prove that Euclid's algorithm,Bezout's equation and Divi-sion algorithm are equivalent to each other.Our result shows that Euclid has preliminarily established the theory of divisibility and t... In this paper,we prove that Euclid's algorithm,Bezout's equation and Divi-sion algorithm are equivalent to each other.Our result shows that Euclid has preliminarily established the theory of divisibility and the greatest common divisor.We further provided several suggestions for teaching. 展开更多
关键词 Euclid's algorithm Division algorithm Bezout's equation
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An Algorithm for Cloud-based Web Service Combination Optimization Through Plant Growth Simulation
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作者 Li Qiang Qin Huawei +1 位作者 Qiao Bingqin Wu Ruifang 《系统仿真学报》 北大核心 2025年第2期462-473,共12页
In order to improve the efficiency of cloud-based web services,an improved plant growth simulation algorithm scheduling model.This model first used mathematical methods to describe the relationships between cloud-base... In order to improve the efficiency of cloud-based web services,an improved plant growth simulation algorithm scheduling model.This model first used mathematical methods to describe the relationships between cloud-based web services and the constraints of system resources.Then,a light-induced plant growth simulation algorithm was established.The performance of the algorithm was compared through several plant types,and the best plant model was selected as the setting for the system.Experimental results show that when the number of test cloud-based web services reaches 2048,the model being 2.14 times faster than PSO,2.8 times faster than the ant colony algorithm,2.9 times faster than the bee colony algorithm,and a remarkable 8.38 times faster than the genetic algorithm. 展开更多
关键词 cloud-based service scheduling algorithm resource constraint load optimization cloud computing plant growth simulation algorithm
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基于改进K-shell混合度分解法的有源配电网脆弱节点评估
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作者 段宏 郭成 陈凤仙 《电力科学与技术学报》 北大核心 2025年第1期67-76,共10页
针对现有配电网节点脆弱性评估方法存在指标选取困难、指标权重片面而难以用于有源配电网脆弱节点评估的问题,提出一种基于改进K-壳(K-shell)混合度分解法(mixed degree decomposition,MDD)的有源配电网脆弱节点评估方法。首先,提出基... 针对现有配电网节点脆弱性评估方法存在指标选取困难、指标权重片面而难以用于有源配电网脆弱节点评估的问题,提出一种基于改进K-壳(K-shell)混合度分解法(mixed degree decomposition,MDD)的有源配电网脆弱节点评估方法。首先,提出基于信息熵理论改进的K-shell混合度分解法,实现配电网节点脆弱度层级划分;随后,结合分布式电源的地理位置和随机特性,建立基于核密度估计和Copula理论的分布式电源随机出力模型;最后,基于风险理论提出以节点运行风险作为权重修正因子的配电网脆弱节点评估方法。所提方法能有效评估有源配电网的脆弱节点,且面对大规模或超大规模的配电网脆弱节点评估时具有更强的计算效率。通过对IEEE 123系统的算例分析验证所提方法的可行性和优越性。 展开更多
关键词 配电网 分布式电源 脆弱节点 COPULA理论 复杂网络理论 改进的k-shell混合度分解法
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Multi-QoS routing algorithm based on reinforcement learning for LEO satellite networks 被引量:1
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作者 ZHANG Yifan DONG Tao +1 位作者 LIU Zhihui JIN Shichao 《Journal of Systems Engineering and Electronics》 2025年第1期37-47,共11页
Low Earth orbit(LEO)satellite networks exhibit distinct characteristics,e.g.,limited resources of individual satellite nodes and dynamic network topology,which have brought many challenges for routing algorithms.To sa... Low Earth orbit(LEO)satellite networks exhibit distinct characteristics,e.g.,limited resources of individual satellite nodes and dynamic network topology,which have brought many challenges for routing algorithms.To satisfy quality of service(QoS)requirements of various users,it is critical to research efficient routing strategies to fully utilize satellite resources.This paper proposes a multi-QoS information optimized routing algorithm based on reinforcement learning for LEO satellite networks,which guarantees high level assurance demand services to be prioritized under limited satellite resources while considering the load balancing performance of the satellite networks for low level assurance demand services to ensure the full and effective utilization of satellite resources.An auxiliary path search algorithm is proposed to accelerate the convergence of satellite routing algorithm.Simulation results show that the generated routing strategy can timely process and fully meet the QoS demands of high assurance services while effectively improving the load balancing performance of the link. 展开更多
关键词 low Earth orbit(LEO)satellite network reinforcement learning multi-quality of service(QoS) routing algorithm
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Research on three-dimensional attack area based on improved backtracking and ALPS-GP algorithms of air-to-air missile
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作者 ZHANG Haodi WANG Yuhui HE Jiale 《Journal of Systems Engineering and Electronics》 2025年第1期292-310,共19页
In the field of calculating the attack area of air-to-air missiles in modern air combat scenarios,the limitations of existing research,including real-time calculation,accuracy efficiency trade-off,and the absence of t... In the field of calculating the attack area of air-to-air missiles in modern air combat scenarios,the limitations of existing research,including real-time calculation,accuracy efficiency trade-off,and the absence of the three-dimensional attack area model,restrict their practical applications.To address these issues,an improved backtracking algorithm is proposed to improve calculation efficiency.A significant reduction in solution time and maintenance of accuracy in the three-dimensional attack area are achieved by using the proposed algorithm.Furthermore,the age-layered population structure genetic programming(ALPS-GP)algorithm is introduced to determine an analytical polynomial model of the three-dimensional attack area,considering real-time requirements.The accuracy of the polynomial model is enhanced through the coefficient correction using an improved gradient descent algorithm.The study reveals a remarkable combination of high accuracy and efficient real-time computation,with a mean error of 91.89 m using the analytical polynomial model of the three-dimensional attack area solved in just 10^(-4)s,thus meeting the requirements of real-time combat scenarios. 展开更多
关键词 air combat three-dimensional attack area improved backtracking algorithm age-layered population structure genetic programming(ALPS-GP) gradient descent algorithm
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Topological optimization of metamaterial absorber based on improved estimation of distribution algorithm
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作者 TAO Shifei LIU Beichen +2 位作者 LIU Sixing WU Fan WANG Hao 《Journal of Systems Engineering and Electronics》 2025年第3期634-641,共8页
An improved estimation of distribution algorithm(IEDA)is proposed in this paper for efficient design of metamaterial absorbers.This algorithm establishes a probability model through the selected dominant groups and sa... An improved estimation of distribution algorithm(IEDA)is proposed in this paper for efficient design of metamaterial absorbers.This algorithm establishes a probability model through the selected dominant groups and samples from the model to obtain the next generation,avoiding the problem of building-blocks destruction caused by crossover and mutation.Neighboring search from artificial bee colony algorithm(ABCA)is introduced to enhance the local optimization ability and improved to raise the speed of convergence.The probability model is modified by boundary correction and loss correction to enhance the robustness of the algorithm.The proposed IEDA is compared with other intelligent algorithms in relevant references.The results show that the proposed IEDA has faster convergence speed and stronger optimization ability,proving the feasibility and effectiveness of the algorithm. 展开更多
关键词 METAMATERIAL topological optimization estimation of distribution algorithm
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An improved genetic algorithm for causal discovery
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作者 MAO Tengjiao BU Xianjin +2 位作者 CAI Chunxiao LU Yue DU Jing 《Journal of Systems Engineering and Electronics》 2025年第3期768-777,共10页
The learning algorithms of causal discovery mainly include score-based methods and genetic algorithms(GA).The score-based algorithms are prone to searching space explosion.Classical GA is slow to converge,and prone to... The learning algorithms of causal discovery mainly include score-based methods and genetic algorithms(GA).The score-based algorithms are prone to searching space explosion.Classical GA is slow to converge,and prone to falling into local optima.To address these issues,an improved GA with domain knowledge(IGADK)is proposed.Firstly,domain knowledge is incorporated into the learning process of causality to construct a new fitness function.Secondly,a dynamical mutation operator is introduced in the algorithm to accelerate the convergence rate.Finally,an experiment is conducted on simulation data,which compares the classical GA with IGADK with domain knowledge of varying accuracy.The IGADK can greatly reduce the number of iterations,populations,and samples required for learning,which illustrates the efficiency and effectiveness of the proposed algorithm. 展开更多
关键词 genetic algorithm(GA) causal discovery convergence rate fitness function mutation operator
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Multi-platform collaborative MRC-PSO algorithm for anti-ship missile path planning
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作者 LIU Gang GUO Xinyuan +2 位作者 HUANG Dong CHEN Kezhong LI Wu 《Journal of Systems Engineering and Electronics》 2025年第2期494-509,共16页
To solve the problem of multi-platform collaborative use in anti-ship missile (ASM) path planning, this paper pro-posed multi-operator real-time constraints particle swarm opti-mization (MRC-PSO) algorithm. MRC-PSO al... To solve the problem of multi-platform collaborative use in anti-ship missile (ASM) path planning, this paper pro-posed multi-operator real-time constraints particle swarm opti-mization (MRC-PSO) algorithm. MRC-PSO algorithm utilizes a semi-rasterization environment modeling technique and inte-grates the geometric gradient law of ASMs which distinguishes itself from other collaborative path planning algorithms by fully considering the coupling between collaborative paths. Then, MRC-PSO algorithm conducts chunked stepwise recursive evo-lution of particles while incorporating circumvent, coordination, and smoothing operators which facilitates local selection opti-mization of paths, gradually reducing algorithmic space, accele-rating convergence, and enhances path cooperativity. Simula-tion experiments comparing the MRC-PSO algorithm with the PSO algorithm, genetic algorithm and operational area cluster real-time restriction (OACRR)-PSO algorithm, which demon-strate that the MRC-PSO algorithm has a faster convergence speed, and the average number of iterations is reduced by approximately 75%. It also proves that it is equally effective in resolving complex scenarios involving multiple obstacles. More-over it effectively addresses the problem of path crossing and can better satisfy the requirements of multi-platform collabora-tive path planning. The experiments are conducted in three col-laborative operation modes, namely, three-to-two, three-to-three, and four-to-two, and the outcomes demonstrate that the algorithm possesses strong universality. 展开更多
关键词 anti-ship missiles multi-platform collaborative path planning particle swarm optimization(PSO)algorithm
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基于邻域K-shell分布的关键节点识别方法 被引量:14
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作者 吴亚丽 任远光 +3 位作者 董昂 周傲然 吴学金 郑帅龙 《计算机工程与应用》 CSCD 北大核心 2024年第2期87-95,共9页
复杂网络中关键节点的精准识别对于网络结构稳定和信息传播起着至关重要的作用。传统K-shell方法仅通过节点在网络中所处位置对节点的重要性进行评估,导致区分度不高。基于此,综合考虑了节点的全局信息和局部信息对节点重要性的影响,提... 复杂网络中关键节点的精准识别对于网络结构稳定和信息传播起着至关重要的作用。传统K-shell方法仅通过节点在网络中所处位置对节点的重要性进行评估,导致区分度不高。基于此,综合考虑了节点的全局信息和局部信息对节点重要性的影响,提出一种基于邻域K-shell分布的关键节点识别方法。该方法通过节点邻域Ks值定义节点的熵,从而反映邻居节点的K-shell分布特征。通过11个网络数据集上的仿真实验,验证了所提方法能够更准确地识别并区分复杂网络中的关键节点。 展开更多
关键词 复杂网络 关键节点 k-shell 易感-感染-恢复模型(SIR)
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改进K-shell算法的城市道路网关键交叉口识别
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作者 裴玉龙 刘鹤行 王子奇 《重庆理工大学学报(自然科学)》 CAS 北大核心 2024年第4期146-153,共8页
交叉口重要性不仅与自身属性相关,还受相邻路段属性的影响,针对城市道路网中关键交叉口识别方法准确率不足的问题,提出一种考虑城市道路网特性的改进K-shell算法。即在传统K-shell算法基础上,综合考虑交叉口及其相邻路段的结构特性与交... 交叉口重要性不仅与自身属性相关,还受相邻路段属性的影响,针对城市道路网中关键交叉口识别方法准确率不足的问题,提出一种考虑城市道路网特性的改进K-shell算法。即在传统K-shell算法基础上,综合考虑交叉口及其相邻路段的结构特性与交通特性,提出交叉口重要度的概念,利用CRITIC法确定交叉口重要度中相关指标的权重系数,对城市道路网中的交叉口进行重要性排序。以哈尔滨市二环内道路网为例,构建级联失效模型,分析随着失效交叉口比例的增加,不同排序方法下的网络效率、网络最大连通子图比率、故障节点比率的波动情况,结果表明,改进K-shell算法能够更加有效地识别城市道路网关键交叉口。 展开更多
关键词 城市道路网 关键交叉口 k-shell 交叉口重要度
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Underwater four-quadrant dual-beam circumferential scanning laser fuze using nonlinear adaptive backscatter filter based on pauseable SAF-LMS algorithm 被引量:3
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作者 Guangbo Xu Bingting Zha +2 位作者 Hailu Yuan Zhen Zheng He Zhang 《Defence Technology(防务技术)》 SCIE EI CAS CSCD 2024年第7期1-13,共13页
The phenomenon of a target echo peak overlapping with the backscattered echo peak significantly undermines the detection range and precision of underwater laser fuzes.To overcome this issue,we propose a four-quadrant ... The phenomenon of a target echo peak overlapping with the backscattered echo peak significantly undermines the detection range and precision of underwater laser fuzes.To overcome this issue,we propose a four-quadrant dual-beam circumferential scanning laser fuze to distinguish various interference signals and provide more real-time data for the backscatter filtering algorithm.This enhances the algorithm loading capability of the fuze.In order to address the problem of insufficient filtering capacity in existing linear backscatter filtering algorithms,we develop a nonlinear backscattering adaptive filter based on the spline adaptive filter least mean square(SAF-LMS)algorithm.We also designed an algorithm pause module to retain the original trend of the target echo peak,improving the time discrimination accuracy and anti-interference capability of the fuze.Finally,experiments are conducted with varying signal-to-noise ratios of the original underwater target echo signals.The experimental results show that the average signal-to-noise ratio before and after filtering can be improved by more than31 d B,with an increase of up to 76%in extreme detection distance. 展开更多
关键词 Laser fuze Underwater laser detection Backscatter adaptive filter Spline least mean square algorithm Nonlinear filtering algorithm
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基于K-shell的城际轨道网络关键节点识别研究 被引量:3
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作者 刘星雨 刘杰 +1 位作者 王喆 黎浩东 《北京交通大学学报》 CAS CSCD 北大核心 2024年第4期181-190,共10页
针对城际轨道交通网络中关键节点较难识别的问题,对网络节点分析方法进行研究.基于K-shell分层法,结合邻居节点的影响以及动静态网络指标,建立了关键节点识别的Ks^(+)法.该模型综合考虑节点度、节点最短路径等静态物理指标与枢纽客流量... 针对城际轨道交通网络中关键节点较难识别的问题,对网络节点分析方法进行研究.基于K-shell分层法,结合邻居节点的影响以及动静态网络指标,建立了关键节点识别的Ks^(+)法.该模型综合考虑节点度、节点最短路径等静态物理指标与枢纽客流量、运营强度等动态运营指标,计算节点的综合评价值.通过K-shell分层算法评估节点的全局核心位置,结合邻居节点的影响力评估节点的局部重要性,最终计算节点k_(s)^(+)值以衡量其在网络中的影响力.利用传染病(Susceptible-Infectious-Recvered,SIR)模型与长三角轨道网络数据为实例,检测了算法的有效性.研究结果表明:识别出的关键节点与城市影响力基本一致,如前4个节点均是长三角地区的直辖市节点和省会城市节点;准确识别了网络中的核心节点与非核心节点,并将线路更重要、客流更多的核心节点排在前列;Ks^(+)识别出的关键节点在SIR仿真中传播速率较其他算法快1~3次迭代,客流损失峰值增加7%. 展开更多
关键词 铁路运输 关键节点 Ks^(+)算法 复杂轨道网络 梯度提升机算法
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Product quality prediction based on RBF optimized by firefly algorithm 被引量:3
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作者 HAN Huihui WANG Jian +1 位作者 CHEN Sen YAN Manting 《Journal of Systems Engineering and Electronics》 SCIE EI CSCD 2024年第1期105-117,共13页
With the development of information technology,a large number of product quality data in the entire manufacturing process is accumulated,but it is not explored and used effectively.The traditional product quality pred... With the development of information technology,a large number of product quality data in the entire manufacturing process is accumulated,but it is not explored and used effectively.The traditional product quality prediction models have many disadvantages,such as high complexity and low accuracy.To overcome the above problems,we propose an optimized data equalization method to pre-process dataset and design a simple but effective product quality prediction model:radial basis function model optimized by the firefly algorithm with Levy flight mechanism(RBFFALM).First,the new data equalization method is introduced to pre-process the dataset,which reduces the dimension of the data,removes redundant features,and improves the data distribution.Then the RBFFALFM is used to predict product quality.Comprehensive expe riments conducted on real-world product quality datasets validate that the new model RBFFALFM combining with the new data pre-processing method outperforms other previous me thods on predicting product quality. 展开更多
关键词 product quality prediction data pre-processing radial basis function swarm intelligence optimization algorithm
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Optimization of jamming formation of USV offboard active decoy clusters based on an improved PSO algorithm 被引量:1
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作者 Zhaodong Wu Yasong Luo Shengliang Hu 《Defence Technology(防务技术)》 SCIE EI CAS CSCD 2024年第2期529-540,共12页
Offboard active decoys(OADs)can effectively jam monopulse radars.However,for missiles approaching from a particular direction and distance,the OAD should be placed at a specific location,posing high requirements for t... Offboard active decoys(OADs)can effectively jam monopulse radars.However,for missiles approaching from a particular direction and distance,the OAD should be placed at a specific location,posing high requirements for timing and deployment.To improve the response speed and jamming effect,a cluster of OADs based on an unmanned surface vehicle(USV)is proposed.The formation of the cluster determines the effectiveness of jamming.First,based on the mechanism of OAD jamming,critical conditions are identified,and a method for assessing the jamming effect is proposed.Then,for the optimization of the cluster formation,a mathematical model is built,and a multi-tribe adaptive particle swarm optimization algorithm based on mutation strategy and Metropolis criterion(3M-APSO)is designed.Finally,the formation optimization problem is solved and analyzed using the 3M-APSO algorithm under specific scenarios.The results show that the improved algorithm has a faster convergence rate and superior performance as compared to the standard Adaptive-PSO algorithm.Compared with a single OAD,the optimal formation of USV-OAD cluster effectively fills the blind area and maximizes the use of jamming resources. 展开更多
关键词 Electronic countermeasure Offboard active decoy USV cluster Jamming formation optimization Improved PSO algorithm
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结构洞理论视角下的复杂工程支配网络综合项目排序方法 被引量:2
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作者 张可 刘思敏 +1 位作者 张政 马敏 《系统管理学报》 北大核心 2025年第2期389-399,共11页
复杂工程包含的项目众多,对项目的重要性进行综合排序,是工程实际决策亟须解决的问题。然而,现有方法忽略了项目之间的联系且分析视角单一,导致排序结果区分度不高。为此,基于复杂工程支配网络,提出结构洞理论视角下的综合项目排序方法... 复杂工程包含的项目众多,对项目的重要性进行综合排序,是工程实际决策亟须解决的问题。然而,现有方法忽略了项目之间的联系且分析视角单一,导致排序结果区分度不高。为此,基于复杂工程支配网络,提出结构洞理论视角下的综合项目排序方法。首先,引入结构洞理论,构建项目影响广泛性的度量模型。其次,利用k-shell算法对项目中心度进行重要性评价及层级划分,构建项目的全局重要度评价模型。在此基础上,融合结构洞理论与k-shell算法,提出项目重要性综合排序方法。最后,将该方法应用于算例网络和实际工程,并与其他方法进行了对比分析。结果显示,提出的项目排序方法具有更高的区分度,能够适应项目评价的多维度要求,为复杂工程的决策提供了参考。 展开更多
关键词 工程支配网络 结构洞理论 k-shell算法 项目排序
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Novel method for extraction of ship target with overlaps in SAR image via EM algorithm 被引量:1
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作者 CAO Rui WANG Yong 《Journal of Systems Engineering and Electronics》 SCIE CSCD 2024年第4期874-887,共14页
The quality of synthetic aperture radar(SAR)image degrades in the case of multiple imaging projection planes(IPPs)and multiple overlapping ship targets,and then the performance of target classification and recognition... The quality of synthetic aperture radar(SAR)image degrades in the case of multiple imaging projection planes(IPPs)and multiple overlapping ship targets,and then the performance of target classification and recognition can be influenced.For addressing this issue,a method for extracting ship targets with overlaps via the expectation maximization(EM)algorithm is pro-posed.First,the scatterers of ship targets are obtained via the target detection technique.Then,the EM algorithm is applied to extract the scatterers of a single ship target with a single IPP.Afterwards,a novel image amplitude estimation approach is pro-posed,with which the radar image of a single target with a sin-gle IPP can be generated.The proposed method can accom-plish IPP selection and targets separation in the image domain,which can improve the image quality and reserve the target information most possibly.Results of simulated and real mea-sured data demonstrate the effectiveness of the proposed method. 展开更多
关键词 expectation maximization(EM)algorithm image processing imaging projection plane(IPP) overlapping ship tar-get synthetic aperture radar(SAR)
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Topological optimization of ballistic protective structures through genetic algorithms in a vulnerability-driven environment
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作者 Salvatore Annunziata Luca Lomazzi +1 位作者 Marco Giglio Andrea Manes 《Defence Technology(防务技术)》 SCIE EI CAS CSCD 2024年第10期125-137,共13页
Reducing the vulnerability of a platform,i.e.,the risk of being affected by hostile objects,is of paramount importance in the design process of vehicles,especially aircraft.A simple and effective way to decrease vulne... Reducing the vulnerability of a platform,i.e.,the risk of being affected by hostile objects,is of paramount importance in the design process of vehicles,especially aircraft.A simple and effective way to decrease vulnerability is to introduce protective structures to intercept and possibly stop threats.However,this type of solution can lead to a significant increase in weight,affecting the performance of the aircraft.For this reason,it is crucial to study possible solutions that allow reducing the vulnerability of the aircraft while containing the increase in structural weight.One possible strategy is to optimize the topology of protective solutions to find the optimal balance between vulnerability and the weight of the added structures.Among the many optimization techniques available in the literature for this purpose,multiobjective genetic algorithms stand out as promising tools.In this context,this work proposes the use of a in-house software for vulnerability calculation to guide the process of topology optimization through multi-objective genetic algorithms,aiming to simultaneously minimize the weight of protective structures and vulnerability.In addition to the use of the in-house software,which itself represents a novelty in the field of topology optimization of structures,the method incorporates a custom mutation function within the genetic algorithm,specifically developed using a graph-based approach to ensure the continuity of the generated structures.The tool developed for this work is capable of generating protections with optimized layouts considering two different types of impacting objects,namely bullets and fragments from detonating objects.The software outputs a set of non-dominated solutions describing different topologies that the user can choose from. 展开更多
关键词 Topological optimization Protective structure Genetic algorithm SURVIVABILITY VULNERABILITY
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Research on User Profile Construction Method Based on Improved TF-IDF Algorithm
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作者 SHAO Ze-ming LI Yu-ang +4 位作者 YANG Ke WANG Guo-peng LIU Xing-guo CHEN Han-ning SI Zhan-jun 《印刷与数字媒体技术研究》 CAS 北大核心 2024年第6期110-116,共7页
In the data-driven era of the internet and business environments,constructing accurate user profiles is paramount for personalized user understanding and classification.The traditional TF-IDF algorithm has some limita... In the data-driven era of the internet and business environments,constructing accurate user profiles is paramount for personalized user understanding and classification.The traditional TF-IDF algorithm has some limitations when evaluating the impact of words on classification results.Consequently,an improved TF-IDF-K algorithm was introduced in this study,which included an equalization factor,aimed at constructing user profiles by processing and analyzing user search records.Through the training and prediction capabilities of a Support Vector Machine(SVM),it enabled the prediction of user demographic attributes.The experimental results demonstrated that the TF-IDF-K algorithm has achieved a significant improvement in classification accuracy and reliability. 展开更多
关键词 TF-IDF-K algorithm User profiling Equalization factor SVM
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基于Petri网和Banker’s algorithm的数字孪生车间死锁判断方法 被引量:1
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作者 杨逸风 陈亚洲 +2 位作者 陈一明 林晓川 王鸿星 《图学学报》 CSCD 北大核心 2024年第3期585-593,共9页
车间生产流程中资源分配或工序安排不合理会使生产流程出现死锁现象,导致无法继续生产,大大降低车间生产效率。为解决上述问题,综合Petri网和Banker’s algorithm理论将车间死锁的形成条件分为互斥等待、占有等待、循环等待和不可剥夺4... 车间生产流程中资源分配或工序安排不合理会使生产流程出现死锁现象,导致无法继续生产,大大降低车间生产效率。为解决上述问题,综合Petri网和Banker’s algorithm理论将车间死锁的形成条件分为互斥等待、占有等待、循环等待和不可剥夺4种,并以这4种条件为基础,将死锁分为资源分配死锁、进程顺序死锁、协作对象死锁和动态资源死锁的4种不同表现形式。基于Banker’s algorithm判断死锁存在、基于改进时间可达性分析法确定车间死锁发生的具体位置,建立不同死锁表现形式下的死锁恢复策略,采用Tina和Unity 3D等软件将该方法集成到车间数字孪生系统中,实现车间流程死锁监测和预测功能。最后以某精密冲压车间零件生产过程为例进行了验证,结果表明该方法能有效实现生产流程实时监控和高效预测。 展开更多
关键词 生产车间 PETRI网 银行家算法 死锁 监控 死锁恢复
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