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PID Steering Control Method of Agricultural Robot Based on Fusion of Particle Swarm Optimization and Genetic Algorithm
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作者 ZHAO Longlian ZHANG Jiachuang +2 位作者 LI Mei DONG Zhicheng LI Junhui 《农业机械学报》 北大核心 2026年第1期358-367,共10页
Aiming to solve the steering instability and hysteresis of agricultural robots in the process of movement,a fusion PID control method of particle swarm optimization(PSO)and genetic algorithm(GA)was proposed.The fusion... Aiming to solve the steering instability and hysteresis of agricultural robots in the process of movement,a fusion PID control method of particle swarm optimization(PSO)and genetic algorithm(GA)was proposed.The fusion algorithm took advantage of the fast optimization ability of PSO to optimize the population screening link of GA.The Simulink simulation results showed that the convergence of the fitness function of the fusion algorithm was accelerated,the system response adjustment time was reduced,and the overshoot was almost zero.Then the algorithm was applied to the steering test of agricultural robot in various scenes.After modeling the steering system of agricultural robot,the steering test results in the unloaded suspended state showed that the PID control based on fusion algorithm reduced the rise time,response adjustment time and overshoot of the system,and improved the response speed and stability of the system,compared with the artificial trial and error PID control and the PID control based on GA.The actual road steering test results showed that the PID control response rise time based on the fusion algorithm was the shortest,about 4.43 s.When the target pulse number was set to 100,the actual mean value in the steady-state regulation stage was about 102.9,which was the closest to the target value among the three control methods,and the overshoot was reduced at the same time.The steering test results under various scene states showed that the PID control based on the proposed fusion algorithm had good anti-interference ability,it can adapt to the changes of environment and load and improve the performance of the control system.It was effective in the steering control of agricultural robot.This method can provide a reference for the precise steering control of other robots. 展开更多
关键词 agricultural robot steering PID control particle swarm optimization algorithm genetic algorithm
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Flood predictions from metrics to classes by multiple machine learning algorithms coupling with clustering-deduced membership degree
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作者 ZHAI Xiaoyan ZHANG Yongyong +5 位作者 XIA Jun ZHANG Yongqiang TANG Qiuhong SHAO Quanxi CHEN Junxu ZHANG Fan 《Journal of Geographical Sciences》 2026年第1期149-176,共28页
Accurate prediction of flood events is important for flood control and risk management.Machine learning techniques contributed greatly to advances in flood predictions,and existing studies mainly focused on predicting... Accurate prediction of flood events is important for flood control and risk management.Machine learning techniques contributed greatly to advances in flood predictions,and existing studies mainly focused on predicting flood resource variables using single or hybrid machine learning techniques.However,class-based flood predictions have rarely been investigated,which can aid in quickly diagnosing comprehensive flood characteristics and proposing targeted management strategies.This study proposed a prediction approach of flood regime metrics and event classes coupling machine learning algorithms with clustering-deduced membership degrees.Five algorithms were adopted for this exploration.Results showed that the class membership degrees accurately determined event classes with class hit rates up to 100%,compared with the four classes clustered from nine regime metrics.The nonlinear algorithms(Multiple Linear Regression,Random Forest,and least squares-Support Vector Machine)outperformed the linear techniques(Multiple Linear Regression and Stepwise Regression)in predicting flood regime metrics.The proposed approach well predicted flood event classes with average class hit rates of 66.0%-85.4%and 47.2%-76.0%in calibration and validation periods,respectively,particularly for the slow and late flood events.The predictive capability of the proposed prediction approach for flood regime metrics and classes was considerably stronger than that of hydrological modeling approach. 展开更多
关键词 flood regime metrics class prediction machine learning algorithms hydrological model
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Equivalent Modeling with Passive Filter Parameter Clustering for Photovoltaic Power Stations Based on a Particle Swarm Optimization K-Means Algorithm
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作者 Binjiang Hu Yihua Zhu +3 位作者 Liang Tu Zun Ma Xian Meng Kewei Xu 《Energy Engineering》 2026年第1期431-459,共29页
This paper proposes an equivalent modeling method for photovoltaic(PV)power stations via a particle swarm optimization(PSO)K-means clustering(KMC)algorithm with passive filter parameter clustering to address the compl... This paper proposes an equivalent modeling method for photovoltaic(PV)power stations via a particle swarm optimization(PSO)K-means clustering(KMC)algorithm with passive filter parameter clustering to address the complexities,simulation time cost and convergence problems of detailed PV power station models.First,the amplitude–frequency curves of different filter parameters are analyzed.Based on the results,a grouping parameter set for characterizing the external filter characteristics is established.These parameters are further defined as clustering parameters.A single PV inverter model is then established as a prerequisite foundation.The proposed equivalent method combines the global search capability of PSO with the rapid convergence of KMC,effectively overcoming the tendency of KMC to become trapped in local optima.This approach enhances both clustering accuracy and numerical stability when determining equivalence for PV inverter units.Using the proposed clustering method,both a detailed PV power station model and an equivalent model are developed and compared.Simulation and hardwarein-loop(HIL)results based on the equivalent model verify that the equivalent method accurately represents the dynamic characteristics of PVpower stations and adapts well to different operating conditions.The proposed equivalent modeling method provides an effective analysis tool for future renewable energy integration research. 展开更多
关键词 Photovoltaic power station multi-machine equivalentmodeling particle swarmoptimization K-means clustering algorithm
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GSLDWOA: A Feature Selection Algorithm for Intrusion Detection Systems in IIoT
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作者 Wanwei Huang Huicong Yu +3 位作者 Jiawei Ren Kun Wang Yanbu Guo Lifeng Jin 《Computers, Materials & Continua》 2026年第1期2006-2029,共24页
Existing feature selection methods for intrusion detection systems in the Industrial Internet of Things often suffer from local optimality and high computational complexity.These challenges hinder traditional IDS from... Existing feature selection methods for intrusion detection systems in the Industrial Internet of Things often suffer from local optimality and high computational complexity.These challenges hinder traditional IDS from effectively extracting features while maintaining detection accuracy.This paper proposes an industrial Internet ofThings intrusion detection feature selection algorithm based on an improved whale optimization algorithm(GSLDWOA).The aim is to address the problems that feature selection algorithms under high-dimensional data are prone to,such as local optimality,long detection time,and reduced accuracy.First,the initial population’s diversity is increased using the Gaussian Mutation mechanism.Then,Non-linear Shrinking Factor balances global exploration and local development,avoiding premature convergence.Lastly,Variable-step Levy Flight operator and Dynamic Differential Evolution strategy are introduced to improve the algorithm’s search efficiency and convergence accuracy in highdimensional feature space.Experiments on the NSL-KDD and WUSTL-IIoT-2021 datasets demonstrate that the feature subset selected by GSLDWOA significantly improves detection performance.Compared to the traditional WOA algorithm,the detection rate and F1-score increased by 3.68%and 4.12%.On the WUSTL-IIoT-2021 dataset,accuracy,recall,and F1-score all exceed 99.9%. 展开更多
关键词 Industrial Internet of Things intrusion detection system feature selection whale optimization algorithm Gaussian mutation
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Identification of small impact craters in Chang’e-4 landing areas using a new multi-scale fusion crater detection algorithm
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作者 FangChao Liu HuiWen Liu +7 位作者 Li Zhang Jian Chen DiJun Guo Bo Li ChangQing Liu ZongCheng Ling Ying-Bo Lu JunSheng Yao 《Earth and Planetary Physics》 2026年第1期92-104,共13页
Impact craters are important for understanding the evolution of lunar geologic and surface erosion rates,among other functions.However,the morphological characteristics of these micro impact craters are not obvious an... Impact craters are important for understanding the evolution of lunar geologic and surface erosion rates,among other functions.However,the morphological characteristics of these micro impact craters are not obvious and they are numerous,resulting in low detection accuracy by deep learning models.Therefore,we proposed a new multi-scale fusion crater detection algorithm(MSF-CDA)based on the YOLO11 to improve the accuracy of lunar impact crater detection,especially for small craters with a diameter of<1 km.Using the images taken by the LROC(Lunar Reconnaissance Orbiter Camera)at the Chang’e-4(CE-4)landing area,we constructed three separate datasets for craters with diameters of 0-70 m,70-140 m,and>140 m.We then trained three submodels separately with these three datasets.Additionally,we designed a slicing-amplifying-slicing strategy to enhance the ability to extract features from small craters.To handle redundant predictions,we proposed a new Non-Maximum Suppression with Area Filtering method to fuse the results in overlapping targets within the multi-scale submodels.Finally,our new MSF-CDA method achieved high detection performance,with the Precision,Recall,and F1 score having values of 0.991,0.987,and 0.989,respectively,perfectly addressing the problems induced by the lesser features and sample imbalance of small craters.Our MSF-CDA can provide strong data support for more in-depth study of the geological evolution of the lunar surface and finer geological age estimations.This strategy can also be used to detect other small objects with lesser features and sample imbalance problems.We detected approximately 500,000 impact craters in an area of approximately 214 km2 around the CE-4 landing area.By statistically analyzing the new data,we updated the distribution function of the number and diameter of impact craters.Finally,we identified the most suitable lighting conditions for detecting impact crater targets by analyzing the effect of different lighting conditions on the detection accuracy. 展开更多
关键词 impact craters Chang’e-4 landing area multi-scale automatic detection YOLO11 Fusion algorithm
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双参数MRI联合PSA密度在前列腺多发结节中精准诊断前列腺癌的效能研究
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作者 卢斌 周娇 +1 位作者 岑炳奎 李桂妹 《影像技术》 2025年第4期17-22,87,共7页
目的:探讨双参数MRI(bpMRI)联合PSA密度(PSAD)在前列腺多发结节背景下诊断前列腺癌(PCa)的临床价值。方法:回顾性分析2022年1月至2024年10月108例前列腺多发结节背景下疑似PCa患者的临床资料。所有患者均采用西门子Magnetom Skyra 3.0T ... 目的:探讨双参数MRI(bpMRI)联合PSA密度(PSAD)在前列腺多发结节背景下诊断前列腺癌(PCa)的临床价值。方法:回顾性分析2022年1月至2024年10月108例前列腺多发结节背景下疑似PCa患者的临床资料。所有患者均采用西门子Magnetom Skyra 3.0T MRI扫描仪,行T1WI、T2WI、扩散加权成像(DWI)及动态对比增强扫描(DCE),并通过酶联免疫吸附法检测血前列腺特异性抗原(PSA)、游离前列腺特异性抗原(fPSA)、fPSA与总PSA比值(f/tPSA)及PSAD水平。以病理结果为金标准,多因素Logistic回归分析筛选PCa的独立影响因素,绘制受试者工作特征(ROC)曲线评估诊断效能。结果:符合组与误诊组在fPSA、PSAD、bpMRI、mpMRI方面差异有统计学意义(P<0.05),f/tPSA差异无统计学意义。多因素Logistic回归分析显示,PSAD、bpMRI是PCa的主要影响因素(P<0.05)。ROC曲线分析显示,bpMRI的AUC值为0.721,PSAD的AUC值为0.915,两者联合的AUC值达到0.931,显著高于单独使用bpMRI、mpMRI或血清指标(P<0.05)。结论:在前列腺多发结节背景下,bpMRI与PSAD联合应用能显著提高PCa的诊断效能,为临床提供一种经济、有效的诊断策略。 展开更多
关键词 前列腺癌 psa密度 双参数MRI 多参数MRI
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MRI联合血清PSA、PSAD、f/tPSA对早期前列腺癌诊断价值
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作者 陈新国 陈蕾 +1 位作者 肖伟 高峰 《分子诊断与治疗杂志》 2025年第12期2292-2294,2298,共4页
目的分析MRI联合血清前列腺特异性抗原(PSA)、PSA密度(PSAD)、游离PSA(fPSA)与总PSA(tPSA)的比值(f/tPSA)对早期前列腺癌(PCa)诊断价值。方法回顾性选取靖江市人民医院2022年月至2025年1月收治疑似PCa的122例患者为研究对象,依据是否确... 目的分析MRI联合血清前列腺特异性抗原(PSA)、PSA密度(PSAD)、游离PSA(fPSA)与总PSA(tPSA)的比值(f/tPSA)对早期前列腺癌(PCa)诊断价值。方法回顾性选取靖江市人民医院2022年月至2025年1月收治疑似PCa的122例患者为研究对象,依据是否确诊PCa分为PCa组和非PCa组。所有研究对象入院时均接受彩色多普勒超声、MRI相关检查及血清PSA、PSAD、f/tPSA等相关实验室检查。比较两组研究对象MRI参数及血清PSA、PSAD、f/tPSA,分析上述指标在PCa早期诊断中的价值。结果PCa组前列腺体积、表观弥散系数(ADC)、相对ADC(rADC)值均大于非PCa组,差异有统计学意义(P<0.05);PCa组PSA、PSAD均高于非PCa组,f/tPSA低于非PCa组,差异有统计学意义(P<0.05);多因素Logistic回归分析,结果显示,rADC、PSA、PSAD及f/tPSA为PCa发生的独立相关因素(P<0.05);受试者工作特征曲线(ROC)分析显示,rADC、PSA、PSAD及f/tPSA联合诊断的AUC值为0.941(0.884~0.976),显著高于单独诊断(P<0.05)。结论MRI参数联合血清PSA、PSAD、f/tPSA对PCa早期的诊断具有显著的临床价值,值得临床推广。 展开更多
关键词 前列腺癌 MRI 前列腺特异性抗原 早期诊断
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Quantum-inspired ant algorithm for knapsack problems 被引量:3
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作者 Wang Honggang Ma Liang +1 位作者 Zhang Huizhen Li Gaoya 《Journal of Systems Engineering and Electronics》 SCIE EI CSCD 2009年第5期1012-1016,共5页
The knapsack problem is a well-known combinatorial optimization problem which has been proved to be NP-hard.This paper proposes a new algorithm called quantum-inspired ant algorithm(QAA)to solve the knapsack problem.Q... The knapsack problem is a well-known combinatorial optimization problem which has been proved to be NP-hard.This paper proposes a new algorithm called quantum-inspired ant algorithm(QAA)to solve the knapsack problem.QAA takes the advantage of the principles in quantum computing,such as qubit,quantum gate,and quantum superposition of states,to get more probabilistic-based status with small colonies.By updating the pheromone in the ant algorithm and rotating the quantum gate,the algorithm can finally reach the optimal solution.The detailed steps to use QAA are presented,and by solving series of test cases of classical knapsack problems,the effectiveness and generality of the new algorithm are validated. 展开更多
关键词 knapsack problem quantum computing ant algorithm quantum-inspired ant algorithm.
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血清PSA水平与MRI相关参数对老年前列腺良恶性病变的诊断价值 被引量:2
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作者 安宁 何宏艳 +3 位作者 程佳琪 程晓露 赵增喜 张瑞 《河北北方学院学报(自然科学版)》 2025年第2期31-34,38,共5页
目的探讨血清PSA水平与MRI相关参数对老年前列腺良恶性病变的诊断价值。方法选取90例老年前列腺癌患者为观察组,同期90例老年前列腺良性增生患者为对照组。均给予MR扩散加权成像检查,测量其相应的表观扩散系数(apparent diffusion coeff... 目的探讨血清PSA水平与MRI相关参数对老年前列腺良恶性病变的诊断价值。方法选取90例老年前列腺癌患者为观察组,同期90例老年前列腺良性增生患者为对照组。均给予MR扩散加权成像检查,测量其相应的表观扩散系数(apparent diffusion coefficient,ADC),计算ADCmean及相对平均ADC值(relative ADC_(mean),rADCmean)。应用酶联免疫吸附法检测血清PSA水平。收集患者人口学资料、体格检查资料、家族史、个人史及临床资料等,采用单因素及多因素Logistic回归模型分析影响前列腺病变良恶性诊断的独立影响因素;采用受试者工作特征曲线评估不同的预测模型对前列腺癌的诊断效能。结果2组患者血清PSA水平、ADCmean及rADCmean组间差异有统计学意义(P<0.05)。血清PSA水平、ADCmean及rADCmean是老年前列腺恶性肿瘤的独立影响因素;血清PSA的AUC为0.848(0.786~0.910),ADCmean的AUC为0.747(0.676~0.817),rADCmean的AUC为0.788(0.721~0.854),血清PSA联合ADCmean及rADCmean的AUC为0.929(0.893~0.966)。结论血清PSA联合MRI相关参数可显著提高对老年前列腺良恶性病变的诊断效能,对临床上早期区分前列腺良恶性肿瘤具有重要的参考价值。 展开更多
关键词 血清psa 表观扩散系数 相对平均表观扩散系数 前列腺良恶性病变 老年
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A Weight-Coded Evolutionary Algorithm for the Multidimensional Knapsack Problem 被引量:2
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作者 Quan Yuan Zhixin Yang 《Advances in Pure Mathematics》 2016年第10期659-675,共17页
A revised weight-coded evolutionary algorithm (RWCEA) is proposed for solving multidimensional knapsack problems. This RWCEA uses a new decoding method and incorporates a heuristic method in initialization. Computatio... A revised weight-coded evolutionary algorithm (RWCEA) is proposed for solving multidimensional knapsack problems. This RWCEA uses a new decoding method and incorporates a heuristic method in initialization. Computational results show that the RWCEA performs better than a weight-coded evolutionary algorithm pro-posed by Raidl (1999) and to some existing benchmarks, it can yield better results than the ones reported in the OR-library. 展开更多
关键词 Weight-Coding Evolutionary algorithm Multidimensional Knapsack Problem (MKP)
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DWI和DCE联合PSA检测对前列腺癌诊断价值研究 被引量:9
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作者 鲁果果 王轩轩 马爱珍 《罕少疾病杂志》 2025年第1期113-115,共3页
目的分析、探究DWI、DCE联合PSA检测在前列腺癌临床诊断中的应用价值。方法选取我院20216至20232月期间收治的80例前列腺癌患者为研究对象并设置为观察组,同时选取同期来我院接受诊疗的85例前列腺增生(BHP)患者为对照组,对患者临床资料... 目的分析、探究DWI、DCE联合PSA检测在前列腺癌临床诊断中的应用价值。方法选取我院20216至20232月期间收治的80例前列腺癌患者为研究对象并设置为观察组,同时选取同期来我院接受诊疗的85例前列腺增生(BHP)患者为对照组,对患者临床资料进行回顾性分析。两组患者均以病理诊断结果为“金标准”,为两组患者实施常规MRI检查、DCE-MRI检查、DWI检查及血清PSA检测,对比分析不同检测方法在临床诊疗工作的作用与价值。结.果80例前列腺癌患者中,34例患者属于是中央区癌、46例患者属于外周带癌。对照组与观察组在时间信.号强度.曲线类型的分布上存在统计学差异(P<005);根据DWI影像结果提示,前列腺癌病灶信号普遍都为明显高信号,且ADC.数值偏.低,平均ADC值为(069±012)×10^(-3)mm^(2)/s;前列腺增.生增生结节则以稍高信号为主,少部分则提示为高信号,ADC值有所降低,平均ADC值为(104±020)×10^(-3)mm^(2)/s,两组在ADC值上存在统计学差异(P<005)。以DWI+D CE.+PSA联合诊断方式诊断前列腺癌的准确度、灵敏度、特异度、阳性预测值、阴性预测值最高,与其他各项诊断方式比较,差异均有统计学意义(P<005)。结论DWI、DCE在鉴别前列腺癌与前列腺增生症时具备了一定的临床价值的,联合PSA对前列腺癌的诊断效果显著,有助于指导临床治疗方案的合理选择。 展开更多
关键词 DWI DCE psa 前列腺癌
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浮动式核电厂PSA外部事件筛选方法研究
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作者 王小吉 杜政瑀 +4 位作者 蒋孝蔚 张丹 刘余 余述文 彭常宏 《核动力工程》 北大核心 2025年第S2期116-121,共6页
浮动式核电厂(FNPP)因其海上运行环境而面临独特的外部灾害挑战。本文基于陆基核电厂概率安全分析(PSA)的外部事件筛选框架,提出了适用于浮动式核电厂的外部事件筛选方法。通过整合核电厂和船舶的外部事件清单,构建了涵盖水文、气象和... 浮动式核电厂(FNPP)因其海上运行环境而面临独特的外部灾害挑战。本文基于陆基核电厂概率安全分析(PSA)的外部事件筛选框架,提出了适用于浮动式核电厂的外部事件筛选方法。通过整合核电厂和船舶的外部事件清单,构建了涵盖水文、气象和人为灾害的浮动式核电厂外部事件清单,并参考国际标准制定了定性和定量筛选准则及分析流程。经定性筛选、定量筛选进行评估,结果表明,极端风(强风)、热带气旋、风浪流、极端雪、龙卷风和船舶碰撞等事件需重点分析,而极端水温、海冰和飞机坠毁等可被筛除。本研究建立的筛选方法为浮动式核电厂外部事件PSA提供了技术参考。 展开更多
关键词 概率安全分析(psa) 外部事件 浮动式核电厂(FNPP)
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A Hybrid Parallel Multi-Objective Genetic Algorithm for 0/1 Knapsack Problem 被引量:3
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作者 Sudhir B. Jagtap Subhendu Kumar Pani Ganeshchandra Shinde 《Journal of Software Engineering and Applications》 2011年第5期316-319,共4页
In this paper a hybrid parallel multi-objective genetic algorithm is proposed for solving 0/1 knapsack problem. Multi-objective problems with non-convex and discrete Pareto front can take enormous computation time to ... In this paper a hybrid parallel multi-objective genetic algorithm is proposed for solving 0/1 knapsack problem. Multi-objective problems with non-convex and discrete Pareto front can take enormous computation time to converge to the true Pareto front. Hence, the classical multi-objective genetic algorithms (MOGAs) (i.e., non- Parallel MOGAs) may fail to solve such intractable problem in a reasonable amount of time. The proposed hybrid model will combine the best attribute of island and Jakobovic master slave models. We conduct an extensive experimental study in a multi-core system by varying the different size of processors and the result is compared with basic parallel model i.e., master-slave model which is used to parallelize NSGA-II. The experimental results confirm that the hybrid model is showing a clear edge over master-slave model in terms of processing time and approximation to the true Pareto front. 展开更多
关键词 Multi-Objective Genetic algorithm PARALLEL Processing Techniques NSGA-II 0/1 KNApsaCK Problem TRIGGER MODEL CONE Separation MODEL Island MODEL
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基于PSAF-LMS算法的多象限周视激光引信抗云雾干扰方法
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作者 查冰婷 徐光博 +1 位作者 秦建新 张合 《兵工学报》 北大核心 2025年第2期275-286,共12页
叠加在目标回波上的云雾后向散射信号是影响空空导弹周视激光引信测距精度的重要因素。针对目前抗云雾干扰方法适应性差、处理时效低等问题,提出一种基于可暂停样条自适应滤波的最小均方(Pauseable Spline Adaptive Filter-Least Mean S... 叠加在目标回波上的云雾后向散射信号是影响空空导弹周视激光引信测距精度的重要因素。针对目前抗云雾干扰方法适应性差、处理时效低等问题,提出一种基于可暂停样条自适应滤波的最小均方(Pauseable Spline Adaptive Filter-Least Mean Square,PSAF-LMS)算法,并设计了算法在现场可编程门阵列(Field-Programmable Gate Array,FPGA)与ARM的联合实现方案。PSAF-LMS算法可有效减少滤波器的稳态误差,并提高激光引信的时刻鉴别精度和抗干扰能力。此外,利用不同信噪比的目标回波信号进行仿真,并开展了云雾环境滤波效果模拟验证试验。研究结果表明:所提算法能够在34.85μs内有效滤除后向散射,并保留目标波峰原始变化趋势,滤波前后信噪比平均可提高25.15 dB以上。 展开更多
关键词 激光引信 后向散射 自适应滤波 样条最小均方算法
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膜分离耦合PSA提氢工艺在焦炉煤气制合成氨中的应用研究
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作者 李振东 张贵雄 +3 位作者 白雪 刘哲语 宋伟 张贵堂 《现代化工》 北大核心 2025年第S1期392-395,400,共5页
某焦化厂建有年产20万t甲醇装置,配套建有年产7万t合成氨装置。由于近年来甲醇市场低迷,企业计划停运甲醇装置,将合成氨提氢原料气由甲醇驰放气改为焦炉煤气,提氢产生的高热值煤气用于发电,对焦炉煤气实现高效利用;由于原料气组分和温... 某焦化厂建有年产20万t甲醇装置,配套建有年产7万t合成氨装置。由于近年来甲醇市场低迷,企业计划停运甲醇装置,将合成氨提氢原料气由甲醇驰放气改为焦炉煤气,提氢产生的高热值煤气用于发电,对焦炉煤气实现高效利用;由于原料气组分和温度发生改变,导致无法匹配原有PSA提氢工艺。根据实际工况,采用膜分离耦合PSA提氢工艺完成项目改造。改造完成后,得到纯度≥99.7%的产品H_(2),膜非渗透气满足燃气发电系统的压力要求;此项目不仅提高了经济效益,而且为焦化企业提氢工艺改造提供了理论依据和技术支持。 展开更多
关键词 焦炉煤气 膜分离 psa 提氢 合成氨
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重水堆安全壳过滤排气性能改进PSA研究
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作者 任诚 赵明 +2 位作者 许以全 詹文辉 谭坤 《机电产品开发与创新》 2025年第2期29-31,共3页
日本福岛事故后,国际上很多重水堆机组均增设了专设安全壳过滤卸压系统(FCVS),将不可避免的放射性物质不可控释放转变为可控释放。然而,重水堆已经在严重事故管理导则中给出了过滤排气安全壳降压策略,增设FCVS的必要性值得探讨。采用PS... 日本福岛事故后,国际上很多重水堆机组均增设了专设安全壳过滤卸压系统(FCVS),将不可避免的放射性物质不可控释放转变为可控释放。然而,重水堆已经在严重事故管理导则中给出了过滤排气安全壳降压策略,增设FCVS的必要性值得探讨。采用PSA方法,量化对比增设FCVS前后电厂风险的变化情况。通过结果分析,发现现有过滤排气途径的薄弱环节,通过改进加强和增设FCVS分析,均可显著提高不可控释放转变为可控释放的性能。本文为重水堆确定提高安全壳过滤排气性能的改进方案提供支持。 展开更多
关键词 重水堆 过滤排气 psa
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SEMI-DEFINITE RELAXATION ALGORITHM OF MULTIPLE KNAPSACK PROBLEM
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作者 Chen Feng Yao EnyuDept.ofMath.,ZhejiangUniv.,Hangzhou310027,China 《Applied Mathematics(A Journal of Chinese Universities)》 SCIE CSCD 2002年第2期241-250,共10页
The multiple knapsack problem denoted by MKP (B,S,m,n) can be defined as fol- lows.A set B of n items and a set Sof m knapsacks are given such thateach item j has a profit pjand weightwj,and each knapsack i has a ca... The multiple knapsack problem denoted by MKP (B,S,m,n) can be defined as fol- lows.A set B of n items and a set Sof m knapsacks are given such thateach item j has a profit pjand weightwj,and each knapsack i has a capacity Ci.The goal is to find a subset of items of maximum profit such that they have a feasible packing in the knapsacks.MKP(B,S,m,n) is strongly NP- Complete and no polynomial- time approximation algorithm can have an approxima- tion ratio better than0 .5 .In the last ten years,semi- definite programming has been empolyed to solve some combinatorial problems successfully.This paper firstly presents a semi- definite re- laxation algorithm (MKPS) for MKP (B,S,m,n) .It is proved that MKPS have a approxima- tion ratio better than 0 .5 for a subclass of MKP (B,S,m,n) with n≤ 1 0 0 ,m≤ 5 and maxnj=1{ wj} minmi=1{ Ci} ≤ 2 3 . 展开更多
关键词 multiple knapsack problem semi- definite relaxation approximation algorithm combina- torial optimization.
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An Optimal Parallel Algorithm for the Knapsack Problem Based on EREW
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作者 李肯立 蒋盛益 +1 位作者 王卉 李庆华 《Journal of Southwest Jiaotong University(English Edition)》 2003年第2期131-137,共7页
A new parallel algorithm is proposed for the knapsack problem where the method of divide and conquer is adopted. Based on an EREW-SIMD machine with shared memory, the proposed algorithm utilizes O(2 n/4 ) 1-ε ... A new parallel algorithm is proposed for the knapsack problem where the method of divide and conquer is adopted. Based on an EREW-SIMD machine with shared memory, the proposed algorithm utilizes O(2 n/4 ) 1-ε processors, 0≤ ε ≤1, and O(2 n/2 ) memory to find a solution for the n -element knapsack problem in time O(2 n/4 (2 n/4 ) ε) . The cost of the proposed parallel algorithm is O(2 n/2 ) , which is an optimal method for solving the knapsack problem without memory conflicts and an improved result over the past researches. 展开更多
关键词 knapsack problem NP-COMPLETE parallel algorithm divide and conquer
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Improved Parallel Three-List Algorithm for the Knapsack Problem without Memory Conflicts
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作者 潘军 李肯立 李庆华 《Journal of Southwest Jiaotong University(English Edition)》 2006年第1期7-14,共8页
Based on the two-list algorithm and the parallel three-list algorithm, an improved parallel three-list algorithm for knapsack problem is proposed, in which the method of divide and conquer, and parallel merging withou... Based on the two-list algorithm and the parallel three-list algorithm, an improved parallel three-list algorithm for knapsack problem is proposed, in which the method of divide and conquer, and parallel merging without memory conflicts are adopted. To find a solution for the n-element knapsack problem, the proposed algorithm needs O(2^3n/8) time when O(2^3n/8) shared memory units and O(2^n/4) processors are available. The comparisons between the proposed algorithm and 10 existing algorithms show that the improved parallel three-fist algorithm is the first exclusive-read exclusive-write (EREW) parallel algorithm that can solve the knapsack instances in less than O(2^n/2) time when the available hardware resource is smaller than O(2^n/2) , and hence is an improved result over the past researches. 展开更多
关键词 Knapsack problem NP-HARD Parallel algorithm Memory conflicts Hardware-time tradeoff
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An Algorithm of 0-1 Knapsack Problem Based on Economic Model
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作者 Yingying Tian Jianhui Lv Liang Zheng 《Journal of Applied Mathematics and Physics》 2013年第4期31-35,共5页
In order to optimize the knapsack problem further, this paper proposes an innovative model based on dynamic expectation efficiency, and establishes a new optimization algorithm of 0-1 knapsack problem after analysis a... In order to optimize the knapsack problem further, this paper proposes an innovative model based on dynamic expectation efficiency, and establishes a new optimization algorithm of 0-1 knapsack problem after analysis and research. Through analyzing the study of 30 groups of 0-1 knapsack problem from discrete coefficient of the data, we can find that dynamic expectation model can solve the following two types of knapsack problem. Compared to artificial glowworm swam algorithm, the convergence speed of this algorithm is ten times as fast as that of artificial glowworm swam algorithm, and the storage space of this algorithm is one quarter that of artificial glowworm swam algorithm. To sum up, it can be widely used in practical problems. 展开更多
关键词 0-1 KNApsaCK ECONOMIC Model Optimization algorithm STORAGE SPACE
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