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A Full-Newton Step Feasible Interior-Point Algorithm for the Special Weighted Linear Complementarity Problems Based on Algebraic Equivalent Transformation
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作者 Jing GE Mingwang ZHANG Panjie TIAN 《Journal of Mathematical Research with Applications》 2025年第4期555-568,共14页
In this paper,we propose a new full-Newton step feasible interior-point algorithm for the special weighted linear complementarity problems.The proposed algorithm employs the technique of algebraic equivalent transform... In this paper,we propose a new full-Newton step feasible interior-point algorithm for the special weighted linear complementarity problems.The proposed algorithm employs the technique of algebraic equivalent transformation to derive the search direction.It is shown that the proximity measure reduces quadratically at each iteration.Moreover,the iteration bound of the algorithm is as good as the best-known polynomial complexity for these types of problems.Furthermore,numerical results are presented to show the efficiency of the proposed algorithm. 展开更多
关键词 interior-point algorithm weighted linear complementarity problem algebraic equivalent transformation search direction iteration complexity
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A Full-Newton Step Feasible Interior-Point Algorithm for the Special Weighted Linear Complementarity Problems Based on a Kernel Function 被引量:2
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作者 GENG Jie ZHANG Mingwang ZHU Dechun 《Wuhan University Journal of Natural Sciences》 CAS CSCD 2024年第1期29-37,共9页
In this paper,a new full-Newton step primal-dual interior-point algorithm for solving the special weighted linear complementarity problem is designed and analyzed.The algorithm employs a kernel function with a linear ... In this paper,a new full-Newton step primal-dual interior-point algorithm for solving the special weighted linear complementarity problem is designed and analyzed.The algorithm employs a kernel function with a linear growth term to derive the search direction,and by introducing new technical results and selecting suitable parameters,we prove that the iteration bound of the algorithm is as good as best-known polynomial complexity of interior-point methods.Furthermore,numerical results illustrate the efficiency of the proposed method. 展开更多
关键词 interior-point algorithm weighted linear complementarity problem full-newton step kernel function iteration complexity
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Newton迭代优化负泊松比针织物结构设计
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作者 李小潼 岳佳宁 +1 位作者 姜茜 吴利伟 《针织工业》 北大核心 2025年第6期21-25,共5页
基于Newton迭代算法,设计并优化椭圆穿孔负泊松比结构,利用横机制作负泊松比纬编针织物。结果表明:在不同形状与分布条件下,关键几何因素椭圆穿孔弦长a、b与负泊松比v呈正相关,椭圆长短半轴夹角θ与椭圆穿孔间隙s与v呈负相关。设置参数s... 基于Newton迭代算法,设计并优化椭圆穿孔负泊松比结构,利用横机制作负泊松比纬编针织物。结果表明:在不同形状与分布条件下,关键几何因素椭圆穿孔弦长a、b与负泊松比v呈正相关,椭圆长短半轴夹角θ与椭圆穿孔间隙s与v呈负相关。设置参数s为0.50 cm,a、b均为9.00 cm,夹角20°情况下,根据Newton迭代算法得到最优负泊松比值为-0.912 9;为验证算法模拟准确性,设计关键参数s为0.80 cm,a为2.30 cm,b为1.30 cm,θ为35°,结合纬编技术制作针织物,其实际负泊松比为-0.014 0,Newton迭代算法计算负泊松比为-0.013 7,误差0.3%,证明该算法优化准确性高,同样适用设计其他负泊松比纬编针织物。 展开更多
关键词 负泊松比效应 newton迭代算法 纬编针织技术 椭圆穿孔结构
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基于Newton插值法高维代理模型的结构有限元模型修正
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作者 卢祯辉 钱嘉伟 欧阳启东 《建筑技术》 2025年第21期2665-2668,共4页
为了优化基于设计图纸建立的结构有限元模型,得到结构的基准有限元模型,提出了一种基于牛顿插值法的高维模型表示(High-dimensional Model representation based on Newton Interpolation, NEWTHDMR)的结构有限元模型修正方法。NEWT-HDM... 为了优化基于设计图纸建立的结构有限元模型,得到结构的基准有限元模型,提出了一种基于牛顿插值法的高维模型表示(High-dimensional Model representation based on Newton Interpolation, NEWTHDMR)的结构有限元模型修正方法。NEWT-HDMR可以描述结构参数与响应之间的黑箱函数关系以取代有限元软件,联合结构真实响应残差和构造目标函数;结合Jaya算法,通过迭代求解结构待修正参数的修正值,进而修正结构有限元模型。利用简支梁数值模型验证本文提出方法的有效性,并分析对比一阶NEWT–HDMR和二阶NEWT-HDMR在修正精度上的差异。结果表明,NEWT-HDMR模型修正结果可以满足工程要求且二阶NEWT-HDMR修正精度更高,验证该方法在结构有限元模型修正中应用的可行性和可靠性。 展开更多
关键词 有限元模型修正 高维模型表示 Jaya算法 牛顿插值法
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Method for Estimating the State of Health of Lithium-ion Batteries Based on Differential Thermal Voltammetry and Sparrow Search Algorithm-Elman Neural Network 被引量:1
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作者 Yu Zhang Daoyu Zhang TiezhouWu 《Energy Engineering》 EI 2025年第1期203-220,共18页
Precisely estimating the state of health(SOH)of lithium-ion batteries is essential for battery management systems(BMS),as it plays a key role in ensuring the safe and reliable operation of battery systems.However,curr... Precisely estimating the state of health(SOH)of lithium-ion batteries is essential for battery management systems(BMS),as it plays a key role in ensuring the safe and reliable operation of battery systems.However,current SOH estimation methods often overlook the valuable temperature information that can effectively characterize battery aging during capacity degradation.Additionally,the Elman neural network,which is commonly employed for SOH estimation,exhibits several drawbacks,including slow training speed,a tendency to become trapped in local minima,and the initialization of weights and thresholds using pseudo-random numbers,leading to unstable model performance.To address these issues,this study addresses the challenge of precise and effective SOH detection by proposing a method for estimating the SOH of lithium-ion batteries based on differential thermal voltammetry(DTV)and an SSA-Elman neural network.Firstly,two health features(HFs)considering temperature factors and battery voltage are extracted fromthe differential thermal voltammetry curves and incremental capacity curves.Next,the Sparrow Search Algorithm(SSA)is employed to optimize the initial weights and thresholds of the Elman neural network,forming the SSA-Elman neural network model.To validate the performance,various neural networks,including the proposed SSA-Elman network,are tested using the Oxford battery aging dataset.The experimental results demonstrate that the method developed in this study achieves superior accuracy and robustness,with a mean absolute error(MAE)of less than 0.9%and a rootmean square error(RMSE)below 1.4%. 展开更多
关键词 Lithium-ion battery state of health differential thermal voltammetry Sparrow Search algorithm
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Robustness Optimization Algorithm with Multi-Granularity Integration for Scale-Free Networks Against Malicious Attacks 被引量:1
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作者 ZHANG Yiheng LI Jinhai 《昆明理工大学学报(自然科学版)》 北大核心 2025年第1期54-71,共18页
Complex network models are frequently employed for simulating and studyingdiverse real-world complex systems.Among these models,scale-free networks typically exhibit greater fragility to malicious attacks.Consequently... Complex network models are frequently employed for simulating and studyingdiverse real-world complex systems.Among these models,scale-free networks typically exhibit greater fragility to malicious attacks.Consequently,enhancing the robustness of scale-free networks has become a pressing issue.To address this problem,this paper proposes a Multi-Granularity Integration Algorithm(MGIA),which aims to improve the robustness of scale-free networks while keeping the initial degree of each node unchanged,ensuring network connectivity and avoiding the generation of multiple edges.The algorithm generates a multi-granularity structure from the initial network to be optimized,then uses different optimization strategies to optimize the networks at various granular layers in this structure,and finally realizes the information exchange between different granular layers,thereby further enhancing the optimization effect.We propose new network refresh,crossover,and mutation operators to ensure that the optimized network satisfies the given constraints.Meanwhile,we propose new network similarity and network dissimilarity evaluation metrics to improve the effectiveness of the optimization operators in the algorithm.In the experiments,the MGIA enhances the robustness of the scale-free network by 67.6%.This improvement is approximately 17.2%higher than the optimization effects achieved by eight currently existing complex network robustness optimization algorithms. 展开更多
关键词 complex network model MULTI-GRANULARITY scale-free networks ROBUSTNESS algorithm integration
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Short-TermWind Power Forecast Based on STL-IAOA-iTransformer Algorithm:A Case Study in Northwest China 被引量:2
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作者 Zhaowei Yang Bo Yang +5 位作者 Wenqi Liu Miwei Li Jiarong Wang Lin Jiang Yiyan Sang Zhenning Pan 《Energy Engineering》 2025年第2期405-430,共26页
Accurate short-term wind power forecast technique plays a crucial role in maintaining the safety and economic efficiency of smart grids.Although numerous studies have employed various methods to forecast wind power,th... Accurate short-term wind power forecast technique plays a crucial role in maintaining the safety and economic efficiency of smart grids.Although numerous studies have employed various methods to forecast wind power,there remains a research gap in leveraging swarm intelligence algorithms to optimize the hyperparameters of the Transformer model for wind power prediction.To improve the accuracy of short-term wind power forecast,this paper proposes a hybrid short-term wind power forecast approach named STL-IAOA-iTransformer,which is based on seasonal and trend decomposition using LOESS(STL)and iTransformer model optimized by improved arithmetic optimization algorithm(IAOA).First,to fully extract the power data features,STL is used to decompose the original data into components with less redundant information.The extracted components as well as the weather data are then input into iTransformer for short-term wind power forecast.The final predicted short-term wind power curve is obtained by combining the predicted components.To improve the model accuracy,IAOA is employed to optimize the hyperparameters of iTransformer.The proposed approach is validated using real-generation data from different seasons and different power stations inNorthwest China,and ablation experiments have been conducted.Furthermore,to validate the superiority of the proposed approach under different wind characteristics,real power generation data fromsouthwestChina are utilized for experiments.Thecomparative results with the other six state-of-the-art prediction models in experiments show that the proposed model well fits the true value of generation series and achieves high prediction accuracy. 展开更多
关键词 Short-termwind power forecast improved arithmetic optimization algorithm iTransformer algorithm SimuNPS
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Newton-Krylov全隐式时间推进方法及其在叶轮机械内流分析中的应用
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作者 李怡 张倩 +3 位作者 赵家资 徐慎忍 乔磊 王丁喜 《推进技术》 北大核心 2025年第10期58-75,共18页
为将Newton-Krylov全隐式时间推进方法应用于基于雷诺平均纳维斯托克斯(RANS)方程的叶轮机械内流分析中,以此提高叶轮机械内流分析的收敛效率及鲁棒性,本文针对叶轮机械内流分析相比飞机外流分析在方法上需要的补充,发展了考虑旋转周期... 为将Newton-Krylov全隐式时间推进方法应用于基于雷诺平均纳维斯托克斯(RANS)方程的叶轮机械内流分析中,以此提高叶轮机械内流分析的收敛效率及鲁棒性,本文针对叶轮机械内流分析相比飞机外流分析在方法上需要的补充,发展了考虑旋转周期边界、转静交界面及离心力源项的精确雅可比计算方法。后将现有面向飞机外流CFD分析的Newton-Krylov全隐式时间推进方法拓展至多排叶轮机械定常流场分析,并基于此方法开发了适用于飞机外流和叶轮机械内流分析的全隐式时间推进求解器。最后,在一系列典型叶轮机械内流分析算例上验证了所开发的流场求解器的计算精度、收敛效率与鲁棒性。 展开更多
关键词 newton-Krylov方法 叶轮机械 动静交界面 鲁棒性 自适应库朗数
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A LODBO algorithm for multi-UAV search and rescue path planning in disaster areas 被引量:1
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作者 Liman Yang Xiangyu Zhang +2 位作者 Zhiping Li Lei Li Yan Shi 《Chinese Journal of Aeronautics》 2025年第2期200-213,共14页
In disaster relief operations,multiple UAVs can be used to search for trapped people.In recent years,many researchers have proposed machine le arning-based algorithms,sampling-based algorithms,and heuristic algorithms... In disaster relief operations,multiple UAVs can be used to search for trapped people.In recent years,many researchers have proposed machine le arning-based algorithms,sampling-based algorithms,and heuristic algorithms to solve the problem of multi-UAV path planning.The Dung Beetle Optimization(DBO)algorithm has been widely applied due to its diverse search patterns in the above algorithms.However,the update strategies for the rolling and thieving dung beetles of the DBO algorithm are overly simplistic,potentially leading to an inability to fully explore the search space and a tendency to converge to local optima,thereby not guaranteeing the discovery of the optimal path.To address these issues,we propose an improved DBO algorithm guided by the Landmark Operator(LODBO).Specifically,we first use tent mapping to update the population strategy,which enables the algorithm to generate initial solutions with enhanced diversity within the search space.Second,we expand the search range of the rolling ball dung beetle by using the landmark factor.Finally,by using the adaptive factor that changes with the number of iterations.,we improve the global search ability of the stealing dung beetle,making it more likely to escape from local optima.To verify the effectiveness of the proposed method,extensive simulation experiments are conducted,and the result shows that the LODBO algorithm can obtain the optimal path using the shortest time compared with the Genetic Algorithm(GA),the Gray Wolf Optimizer(GWO),the Whale Optimization Algorithm(WOA)and the original DBO algorithm in the disaster search and rescue task set. 展开更多
关键词 Unmanned aerial vehicle Path planning Meta heuristic algorithm DBO algorithm NP-hard problems
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高温气冷堆多组分流动换热耦合系统的Newton-Krylov求解方法研究
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作者 唐焕燃 张汉 +4 位作者 刘礼勋 彭心茹 邬颖杰 郭炯 李富 《原子能科学技术》 北大核心 2025年第2期348-359,共12页
高温气冷堆的进水事故和进气事故是需要特殊考虑的事故,这两类事故中空气或水蒸气会与堆芯石墨发生化学反应生成多种气体并腐蚀石墨。研究化学腐蚀现象的前提是对堆芯中多种气体的流动扩散现象进行研究,相比于单组分问题,这是一个更为... 高温气冷堆的进水事故和进气事故是需要特殊考虑的事故,这两类事故中空气或水蒸气会与堆芯石墨发生化学反应生成多种气体并腐蚀石墨。研究化学腐蚀现象的前提是对堆芯中多种气体的流动扩散现象进行研究,相比于单组分问题,这是一个更为复杂的非线性耦合系统,需要稳定、准确、高效求解。本文以计算性能优异的Newton-Krylov(NK)方法为耦合框架,针对高温气冷堆特点,开发了多组分气体流动耦合计算模块,提出了基于物理特性的NK修正算法,避免非物理解的中间迭代值。通过与高温气冷堆分析程序TINTE的对比验证了新程序的正确性。测试结果表明,在计算效率上NK算法的计算性能约为Picard算法的6~7倍。 展开更多
关键词 高温气冷堆 多物理场 多组分气体 newton-Krylov算法
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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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DDoS Attack Autonomous Detection Model Based on Multi-Strategy Integrate Zebra Optimization Algorithm
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作者 Chunhui Li Xiaoying Wang +2 位作者 Qingjie Zhang Jiaye Liang Aijing Zhang 《Computers, Materials & Continua》 SCIE EI 2025年第1期645-674,共30页
Previous studies have shown that deep learning is very effective in detecting known attacks.However,when facing unknown attacks,models such as Deep Neural Networks(DNN)combined with Long Short-Term Memory(LSTM),Convol... Previous studies have shown that deep learning is very effective in detecting known attacks.However,when facing unknown attacks,models such as Deep Neural Networks(DNN)combined with Long Short-Term Memory(LSTM),Convolutional Neural Networks(CNN)combined with LSTM,and so on are built by simple stacking,which has the problems of feature loss,low efficiency,and low accuracy.Therefore,this paper proposes an autonomous detectionmodel for Distributed Denial of Service attacks,Multi-Scale Convolutional Neural Network-Bidirectional Gated Recurrent Units-Single Headed Attention(MSCNN-BiGRU-SHA),which is based on a Multistrategy Integrated Zebra Optimization Algorithm(MI-ZOA).The model undergoes training and testing with the CICDDoS2019 dataset,and its performance is evaluated on a new GINKS2023 dataset.The hyperparameters for Conv_filter and GRU_unit are optimized using the Multi-strategy Integrated Zebra Optimization Algorithm(MIZOA).The experimental results show that the test accuracy of the MSCNN-BiGRU-SHA model based on the MIZOA proposed in this paper is as high as 0.9971 in the CICDDoS 2019 dataset.The evaluation accuracy of the new dataset GINKS2023 created in this paper is 0.9386.Compared to the MSCNN-BiGRU-SHA model based on the Zebra Optimization Algorithm(ZOA),the detection accuracy on the GINKS2023 dataset has improved by 5.81%,precisionhas increasedby 1.35%,the recallhas improvedby 9%,and theF1scorehas increasedby 5.55%.Compared to the MSCNN-BiGRU-SHA models developed using Grid Search,Random Search,and Bayesian Optimization,the MSCNN-BiGRU-SHA model optimized with the MI-ZOA exhibits better performance in terms of accuracy,precision,recall,and F1 score. 展开更多
关键词 Distributed denial of service attack intrusion detection deep learning zebra optimization algorithm multi-strategy integrated zebra optimization algorithm
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Bearing capacity prediction of open caissons in two-layered clays using five tree-based machine learning algorithms 被引量:1
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作者 Rungroad Suppakul Kongtawan Sangjinda +3 位作者 Wittaya Jitchaijaroen Natakorn Phuksuksakul Suraparb Keawsawasvong Peem Nuaklong 《Intelligent Geoengineering》 2025年第2期55-65,共11页
Open caissons are widely used in foundation engineering because of their load-bearing efficiency and adaptability in diverse soil conditions.However,accurately predicting their undrained bearing capacity in layered so... Open caissons are widely used in foundation engineering because of their load-bearing efficiency and adaptability in diverse soil conditions.However,accurately predicting their undrained bearing capacity in layered soils remains a complex challenge.This study presents a novel application of five ensemble machine(ML)algorithms-random forest(RF),gradient boosting machine(GBM),extreme gradient boosting(XGBoost),adaptive boosting(AdaBoost),and categorical boosting(CatBoost)-to predict the undrained bearing capacity factor(Nc)of circular open caissons embedded in two-layered clay on the basis of results from finite element limit analysis(FELA).The input dataset consists of 1188 numerical simulations using the Tresca failure criterion,varying in geometrical and soil parameters.The FELA was performed via OptumG2 software with adaptive meshing techniques and verified against existing benchmark studies.The ML models were trained on 70% of the dataset and tested on the remaining 30%.Their performance was evaluated using six statistical metrics:coefficient of determination(R²),mean absolute error(MAE),root mean squared error(RMSE),index of scatter(IOS),RMSE-to-standard deviation ratio(RSR),and variance explained factor(VAF).The results indicate that all the models achieved high accuracy,with R²values exceeding 97.6%and RMSE values below 0.02.Among them,AdaBoost and CatBoost consistently outperformed the other methods across both the training and testing datasets,demonstrating superior generalizability and robustness.The proposed ML framework offers an efficient,accurate,and data-driven alternative to traditional methods for estimating caisson capacity in stratified soils.This approach can aid in reducing computational costs while improving reliability in the early stages of foundation design. 展开更多
关键词 Two-layered clay Open caisson Tree-based algorithms FELA Machine learning
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Path Planning for Thermal Power Plant Fan Inspection Robot Based on Improved A^(*)Algorithm 被引量:1
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作者 Wei Zhang Tingfeng Zhang 《Journal of Electronic Research and Application》 2025年第1期233-239,共7页
To improve the efficiency and accuracy of path planning for fan inspection tasks in thermal power plants,this paper proposes an intelligent inspection robot path planning scheme based on an improved A^(*)algorithm.The... To improve the efficiency and accuracy of path planning for fan inspection tasks in thermal power plants,this paper proposes an intelligent inspection robot path planning scheme based on an improved A^(*)algorithm.The inspection robot utilizes multiple sensors to monitor key parameters of the fans,such as vibration,noise,and bearing temperature,and upload the data to the monitoring center.The robot’s inspection path employs the improved A^(*)algorithm,incorporating obstacle penalty terms,path reconstruction,and smoothing optimization techniques,thereby achieving optimal path planning for the inspection robot in complex environments.Simulation results demonstrate that the improved A^(*)algorithm significantly outperforms the traditional A^(*)algorithm in terms of total path distance,smoothness,and detour rate,effectively improving the execution efficiency of inspection tasks. 展开更多
关键词 Power plant fans Inspection robot Path planning Improved A^(*)algorithm
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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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Improved algorithm of multi-mainlobe interference suppression under uncorrelated and coherent conditions 被引量:1
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作者 CAI Miaohong CHENG Qiang +1 位作者 MENG Jinli ZHAO Dehua 《Journal of Southeast University(English Edition)》 2025年第1期84-90,共7页
A new method based on the iterative adaptive algorithm(IAA)and blocking matrix preprocessing(BMP)is proposed to study the suppression of multi-mainlobe interference.The algorithm is applied to precisely estimate the s... A new method based on the iterative adaptive algorithm(IAA)and blocking matrix preprocessing(BMP)is proposed to study the suppression of multi-mainlobe interference.The algorithm is applied to precisely estimate the spatial spectrum and the directions of arrival(DOA)of interferences to overcome the drawbacks associated with conventional adaptive beamforming(ABF)methods.The mainlobe interferences are identified by calculating the correlation coefficients between direction steering vectors(SVs)and rejected by the BMP pretreatment.Then,IAA is subsequently employed to reconstruct a sidelobe interference-plus-noise covariance matrix for the preferable ABF and residual interference suppression.Simulation results demonstrate the excellence of the proposed method over normal methods based on BMP and eigen-projection matrix perprocessing(EMP)under both uncorrelated and coherent circumstances. 展开更多
关键词 mainlobe interference suppression adaptive beamforming spatial spectral estimation iterative adaptive algorithm blocking matrix preprocessing
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Gravitational Collapse and Expansion in the Newton Theory and General Relativity
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作者 Valery V. Vasiliev Leonid V. Fedorov 《Journal of Modern Physics》 2025年第2期294-309,共16页
The paper is devoted to the study of the gravitational collapse within the framework of the spherically symmetric problem in the Newton theory and general relativity on the basis of the pressure-free model of the cont... The paper is devoted to the study of the gravitational collapse within the framework of the spherically symmetric problem in the Newton theory and general relativity on the basis of the pressure-free model of the continuum. In application to the Newton gravitation theory, the analysis consists of three stages. First, we assume that the gravitational force is determined by the initial sphere radius and constant density and does not change in the process of the sphere collapse. The obtained analytical solution allows us to find the collapse time in the first approximation. Second, we construct the step-by-step process in which the gravitational force at a given time moment depends on the current sphere radius and density. The obtained numerical solution specifies the collapse time depending on the number of steps. Third, we find the exact value of the collapse time which is the limit of the step-by-step solutions and study the collapse and the expansion processes in the Newton theory. In application to general relativity, we use the space model corresponding to the special four-dimensional space which is Euclidean with respect to space coordinates and Riemannian with respect to the time coordinate only. The obtained solution specifies two possible scenarios. First, sphere contraction results in the infinitely high density with the finite collapse time, which does not coincide with the conventional result corresponding to the Schwarzschild geometry. Second, sphere expansion with the velocity which increases with a distance from the sphere center and decreases with time. 展开更多
关键词 Gravitational Collapse newton Gravitation Theory General Relativity
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Intelligent sequential multi-impulse collision avoidance method for non-cooperative spacecraft based on an improved search tree algorithm 被引量:1
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作者 Xuyang CAO Xin NING +4 位作者 Zheng WANG Suyi LIU Fei CHENG Wenlong LI Xiaobin LIAN 《Chinese Journal of Aeronautics》 2025年第4期378-393,共16页
The problem of collision avoidance for non-cooperative targets has received significant attention from researchers in recent years.Non-cooperative targets exhibit uncertain states and unpredictable behaviors,making co... The problem of collision avoidance for non-cooperative targets has received significant attention from researchers in recent years.Non-cooperative targets exhibit uncertain states and unpredictable behaviors,making collision avoidance significantly more challenging than that for space debris.Much existing research focuses on the continuous thrust model,whereas the impulsive maneuver model is more appropriate for long-duration and long-distance avoidance missions.Additionally,it is important to minimize the impact on the original mission while avoiding noncooperative targets.On the other hand,the existing avoidance algorithms are computationally complex and time-consuming especially with the limited computing capability of the on-board computer,posing challenges for practical engineering applications.To conquer these difficulties,this paper makes the following key contributions:(A)a turn-based(sequential decision-making)limited-area impulsive collision avoidance model considering the time delay of precision orbit determination is established for the first time;(B)a novel Selection Probability Learning Adaptive Search-depth Search Tree(SPL-ASST)algorithm is proposed for non-cooperative target avoidance,which improves the decision-making efficiency by introducing an adaptive-search-depth mechanism and a neural network into the traditional Monte Carlo Tree Search(MCTS).Numerical simulations confirm the effectiveness and efficiency of the proposed method. 展开更多
关键词 Non-cooperative target Collision avoidance Limited motion area Impulsive maneuver model Search tree algorithm Neural networks
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A Class of Parallel Algorithm for Solving Low-rank Tensor Completion
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作者 LIU Tingyan WEN Ruiping 《应用数学》 北大核心 2025年第4期1134-1144,共11页
In this paper,we established a class of parallel algorithm for solving low-rank tensor completion problem.The main idea is that N singular value decompositions are implemented in N different processors for each slice ... In this paper,we established a class of parallel algorithm for solving low-rank tensor completion problem.The main idea is that N singular value decompositions are implemented in N different processors for each slice matrix under unfold operator,and then the fold operator is used to form the next iteration tensor such that the computing time can be decreased.In theory,we analyze the global convergence of the algorithm.In numerical experiment,the simulation data and real image inpainting are carried out.Experiment results show the parallel algorithm outperform its original algorithm in CPU times under the same precision. 展开更多
关键词 Tensor completion Low-rank CONVERGENCE Parallel algorithm
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基于Newton迭代法的水压试验机充水泵变流量控制
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作者 苗鹏军 李洪臣 +4 位作者 宋东涛 田小江 焦炜 姜大瑛 朱炜 《焊管》 2025年第10期28-33,46,共7页
为了解决直缝埋弧焊管水压试验机在充水泵持续运转时充水泵电机空耗较大的问题,提出了基于Newton迭代法的充水泵变流量控制方法。通过定义充水泵功能零件相应的方程式,推导建立充水泵的力学平衡方程。设定指标量化评估水压试验机的运行... 为了解决直缝埋弧焊管水压试验机在充水泵持续运转时充水泵电机空耗较大的问题,提出了基于Newton迭代法的充水泵变流量控制方法。通过定义充水泵功能零件相应的方程式,推导建立充水泵的力学平衡方程。设定指标量化评估水压试验机的运行状态参数,结合目标流量参数,引入Newton迭代法分析参数平衡关系。在此基础上,计算充水泵比例减压阀开度控制参数,实现变流量控制过程。经过试验可知,该方法对于充水泵的变流量控制效果较好,水力失调度更接近于1,提升了充水泵的稳定性和使用寿命。 展开更多
关键词 水压试验机 充水泵 变流量控制 newton迭代法
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