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Fixed-time Target-guided Coordinate Control of Unmanned Surface Vehicles Based on Dynamic Surface Control
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作者 LI Chao−yi XU Hai−xiang +2 位作者 YU Wen−zhao DU Zhe DING Ya−nan 《船舶力学》 北大核心 2025年第6期849-862,共14页
This paper presents an investigation on the target-guided coordinated control(TACC)of unmanned surface vehicles(USVs).In the scenario of tracking non-cooperative targets,the status information of the target can only b... This paper presents an investigation on the target-guided coordinated control(TACC)of unmanned surface vehicles(USVs).In the scenario of tracking non-cooperative targets,the status information of the target can only be obtained by some USVs.In order to achieve semi-encirclement tracking of noncooperative targets under maritime security conditions,a fixed-time tracking control method based on dynamic surface control(DSC)is proposed in this paper.Firstly,a novel TACC architecture with decoupled kinematic control law and decoupled kinetic control law was designed to reduce the complexity of control system design.Secondly,the proposed DSC-based target-guided kinematic control law including tracking points pre-allocation strategy and sigmoid artificial potential functions(SigAPFs)can avoid collisions during tracking process and optimize kinematic control output.Finally,a fixed-time TACC system was proposed to achieve fast convergence of kinematic and kinetics errors.The effectiveness of the proposed TACC approach in improving target tracking safety and reducing control output chattering was verified by simulation comparison results. 展开更多
关键词 unmanned surface vehicle distributed control target-guided coordinate control fixed-time convergence dynamic surface control
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Data driven prediction of fragment velocity distribution under explosive loading conditions
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作者 Donghwan Noh Piemaan Fazily +4 位作者 Songwon Seo Jaekun Lee Seungjae Seo Hoon Huh Jeong Whan Yoon 《Defence Technology(防务技术)》 2025年第1期109-119,共11页
This study presents a machine learning-based method for predicting fragment velocity distribution in warhead fragmentation under explosive loading condition.The fragment resultant velocities are correlated with key de... This study presents a machine learning-based method for predicting fragment velocity distribution in warhead fragmentation under explosive loading condition.The fragment resultant velocities are correlated with key design parameters including casing dimensions and detonation positions.The paper details the finite element analysis for fragmentation,the characterizations of the dynamic hardening and fracture models,the generation of comprehensive datasets,and the training of the ANN model.The results show the influence of casing dimensions on fragment velocity distributions,with the tendencies indicating increased resultant velocity with reduced thickness,increased length and diameter.The model's predictive capability is demonstrated through the accurate predictions for both training and testing datasets,showing its potential for the real-time prediction of fragmentation performance. 展开更多
关键词 Data driven prediction dynamic fracture model dynamic hardening model FRAGMENTATION Fragment velocity distribution High strain rate Machine learning
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A distributed dynamic mesh model of a helical gear pair with tooth profile errors 被引量:8
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作者 WANG Qi-bin MA Hong-bo +1 位作者 KONG Xian-guang ZHANG Yi-min 《Journal of Central South University》 SCIE EI CAS CSCD 2018年第2期287-303,共17页
A dynamic model of a helical gear rotor system is proposed.Firstly,a generally distributed dynamic model of a helical gear pair with tooth profile errors is developed.The gear mesh is represented by a pair of cylinder... A dynamic model of a helical gear rotor system is proposed.Firstly,a generally distributed dynamic model of a helical gear pair with tooth profile errors is developed.The gear mesh is represented by a pair of cylinders connected by a series of springs and the stiffness of each spring is equal to the effective mesh stiffness.Combining the gear dynamic model with the rotor-bearing system model,the gear-rotor-bearing dynamic model is developed.Then three cases are presented to analyze the dynamic responses of gear systems.The results reveal that the gear dynamic model is effective and advanced for general gear systems,narrow-faced gear,wide-faced gear and gear with tooth profile errors.Finally,the responses of an example helical gear system are also studied to demonstrate the influence of the lead crown reliefs and misalignments.The results show that both of the lead crown relief and misalignment soften the gear mesh stiffness and the responses of the gear system increase with the increasing lead crown reliefs and misalignments. 展开更多
关键词 gear distributed dynamic model tooth profile errors helical gear pair rotor system dynamic response
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Novel algorithm for distributed replicas management based on dynamic programming 被引量:1
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作者 Wang Tao Lu Xianliang Hou Mengshu 《Journal of Systems Engineering and Electronics》 SCIE EI CSCD 2006年第3期669-672,共4页
Replicas can improve the data reliability in distributed system. However, the traditional algorithms for replica management are based on the assumption that all replicas have the uniform reliability, which is inaccura... Replicas can improve the data reliability in distributed system. However, the traditional algorithms for replica management are based on the assumption that all replicas have the uniform reliability, which is inaccurate in some actual systems. To address such problem, a novel algorithm is proposed based on dynamic programming to manage the number and distribution of replicas in different nodes. By using Markov model, replicas management is organized as a multi-phase process, and the recursion equations are provided. In this algorithm, the heterogeneity of nodes, the expense for maintaining replicas and the engaged space have been considered. Under these restricted conditions, this algorithm realizes high data reliability in a distributed system. The results of case analysis prove the feasibility of the algorithm. 展开更多
关键词 distributED replicas MARKOV dynamic programming.
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Distributed collaborative extremum response surface method for mechanical dynamic assembly reliability analysis 被引量:7
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作者 费成巍 白广忱 《Journal of Central South University》 SCIE EI CAS 2013年第9期2414-2422,共9页
To make the dynamic assembly reliability analysis more effective for complex machinery of multi-object multi-discipline(MOMD),distributed collaborative extremum response surface method(DCERSM)was proposed based on ext... To make the dynamic assembly reliability analysis more effective for complex machinery of multi-object multi-discipline(MOMD),distributed collaborative extremum response surface method(DCERSM)was proposed based on extremum response surface method(ERSM).Firstly,the basic theories of the ERSM and DCERSM were investigated,and the strengths of DCERSM were proved theoretically.Secondly,the mathematical model of the DCERSM was established based upon extremum response surface function(ERSF).Finally,this model was applied to the reliability analysis of blade-tip radial running clearance(BTRRC)of an aeroengine high pressure turbine(HPT)to verify its advantages.The results show that the DCERSM can not only reshape the possibility of the reliability analysis for the complex turbo machinery,but also greatly improve the computational speed,save the computational time and improve the computational efficiency while keeping the accuracy.Thus,the DCERSM is verified to be feasible and effective in the dynamic assembly reliability(DAR)analysis of complex machinery.Moreover,this method offers an useful insight for designing and optimizing the dynamic reliability of complex machinery. 展开更多
关键词 complex machinery dynamic assembly reliability (DAR) blade-tip radial running clearance (BTRRC) radial deformation reliability analysis distributed collaborative extremum response surface method (DCERSM) multi-object multidiscipline (MOMD)
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Study on the Medical Image Distributed Dynamic Processing Method
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作者 Zhang Quanhai & Shi PengfeiInstitute of Image Processing and Pattern Recognition, Shanghai Jiaotong University, Shanghai 200030, P. R. China 《Journal of Systems Engineering and Electronics》 SCIE EI CSCD 2003年第4期69-76,共8页
To meet the challenge of implementing rapidly advanced, time-consuming medical image processing algorithms, it is necessary to develop a medical image processing technology to process a 2D or 3D medical image dynamica... To meet the challenge of implementing rapidly advanced, time-consuming medical image processing algorithms, it is necessary to develop a medical image processing technology to process a 2D or 3D medical image dynamically on the web. But in a premier system, only static image processing can be provided with the limitation of web technology. The development of Java and CORBA (common object request broker architecture) overcomes the shortcoming of the web static application and makes the dynamic processing of medical images on the web available. To develop an open solution of distributed computing, we integrate the Java, and web with the CORBA and present a web-based medical image dynamic processing methed, which adopts Java technology as the language to program application and components of the web and utilies the CORBA architecture to cope with heterogeneous property of a complex distributed system. The method also provides a platform-independent, transparent processing architecture to implement the advanced image routines and enable users to access large dataset and resources according to the requirements of medical applications. The experiment in this paper shows that the medical image dynamic processing method implemented on the web by using Java and the CORBA is feasible. 展开更多
关键词 medical image dynamic processing based on web distributed computing INTEROPERATION CORBA.
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Dynamic threshold for SPWVD parameter estimation based on Otsu algorithm 被引量:11
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作者 Ning Ma Jianxin Wang 《Journal of Systems Engineering and Electronics》 SCIE EI CSCD 2013年第6期919-924,共6页
Time-frequency-based methods are proven to be effective for parameter estimation of linear frequency modulation (LFM) signals. The smoothed pseudo Winger-Ville distribution (SPWVD) is used for the parameter estima... Time-frequency-based methods are proven to be effective for parameter estimation of linear frequency modulation (LFM) signals. The smoothed pseudo Winger-Ville distribution (SPWVD) is used for the parameter estimation of multi-LFM signals, and a method of the SPWVD binarization by a dynamic threshold based on the Otsu algorithm is proposed. The proposed method is effective in the demand for the estimation of different parameters and the unknown signal-to-noise ratio (SNR) circumstance. The performance of this method is confirmed by numerical simulation. 展开更多
关键词 parameter estimation smoothed pseudo Winger-Ville distribution (SPWVD) dynamic threshold Otsu algorithm
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Assessment and sequencing of air target threat based on intuitionistic fuzzy entropy and dynamic VIKOR 被引量:33
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作者 ZHANG Kun KONG Weiren +3 位作者 LIU Peipei SHI Jiao LEI Yu ZOU Jie 《Journal of Systems Engineering and Electronics》 SCIE EI CSCD 2018年第2期305-310,共6页
In view of the fact that traditional air target threat assessment methods are difficult to reflect the combat characteristics of uncertain, dynamic and hybrid formation, an algorithm is proposed to solve the multi-tar... In view of the fact that traditional air target threat assessment methods are difficult to reflect the combat characteristics of uncertain, dynamic and hybrid formation, an algorithm is proposed to solve the multi-target threat assessment problems. The target attribute weight is calculated by the intuitionistic fuzzy entropy(IFE) algorithm and the time series weight is gained by the Poisson distribution method based on multi-times data. Finally,assessment and sequencing of the air multi-target threat model based on IFE and dynamic Vlse Kriterijumska Optimizacija I Kompromisno Resenje(VIKOR) is established with an example which indicates that the method is reasonable and effective. 展开更多
关键词 threat assessment intuitionistic fuzzy entropy(IFE) dynamic Vlse Kriterijumska Optimizacija I Kompromisno Resenje(VIKOR) poisson distribution time series weight
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Dynamic assessment method of air target threat based on improved GIFSS 被引量:11
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作者 FENG Jinfu ZHANG Qiang +1 位作者 HU Junhua LIU An 《Journal of Systems Engineering and Electronics》 SCIE EI CSCD 2019年第3期525-534,共10页
As the air combat environment becomes more complicated and changeable, accurate threat assessment of air target has a significant impact on air defense operations. This paper proposes an improved generalized intuition... As the air combat environment becomes more complicated and changeable, accurate threat assessment of air target has a significant impact on air defense operations. This paper proposes an improved generalized intuitionistic fuzzy soft set (GIFSS) method for dynamic assessment of air target threat. Firstly, the threat assessment index is reasonably determined by analyzing the typical characteristics of air targets. Secondly, after the GIFSS at different time is obtained, the index weight is determined by the intuitionistic fuzzy set entropy and the relative entropy theory. Then, the inverse Poisson distribution method is used to determine the weight of time series, and then the time-weighted GIFSS is obtained. Finally, threat assessment of five air targets is carried out by using the improved GIFSS (I-GIFSS) and comparison methods. The validity and superiority of the proposed method are verified by calculation and comparison. 展开更多
关键词 THREAT dynamic assessment generalized intuitionistic FUZZY soft set (GIFSS) intuitionistic FUZZY ENTROPY relative ENTROPY INVERSE POISSON distribution method
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Multi-population and diffusion UMDA for dynamic multimodal problems 被引量:3
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作者 Yan Wu Yuping Wang +1 位作者 Xiaoxiong Liu Jimin Ye 《Journal of Systems Engineering and Electronics》 SCIE EI CSCD 2010年第5期777-783,共7页
In dynamic environments,it is important to track changing optimal solutions over time.Univariate marginal distribution algorithm(UMDA) which is a class algorithm of estimation of distribution algorithms attracts mor... In dynamic environments,it is important to track changing optimal solutions over time.Univariate marginal distribution algorithm(UMDA) which is a class algorithm of estimation of distribution algorithms attracts more and more attention in recent years.In this paper a new multi-population and diffusion UMDA(MDUMDA) is proposed for dynamic multimodal problems.The multi-population approach is used to locate multiple local optima which are useful to find the global optimal solution quickly to dynamic multimodal problems.The diffusion model is used to increase the diversity in a guided fashion,which makes the neighbor individuals of previous optimal solutions move gradually from the previous optimal solutions and enlarge the search space.This approach uses both the information of current population and the part history information of the optimal solutions.Finally experimental studies on the moving peaks benchmark are carried out to evaluate the proposed algorithm and compare the performance of MDUMDA and multi-population quantum swarm optimization(MQSO) from the literature.The experimental results show that the MDUMDA is effective for the function with moving optimum and can adapt to the dynamic environments rapidly. 展开更多
关键词 univariate marginal distribution algorithm(UMDA) dynamic multimodal problems dynamic optimization multipopulation scheme.
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Experimental investigation on dynamic response and damage models of circular RC columns subjected to underwater explosions 被引量:8
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作者 Tie-shuan Zhuang Ming-yang Wang +3 位作者 Jun Wu Cheng-yu Yang Tao Zhang Chao Gao 《Defence Technology(防务技术)》 SCIE EI CAS CSCD 2020年第4期856-875,共20页
Reinforced concrete(RC) columns are widely used as supporting structures for high-piled wharfs.The study of damage model of a RC column due to underwater explosion is a critical issue to assess the wharfs antiknock se... Reinforced concrete(RC) columns are widely used as supporting structures for high-piled wharfs.The study of damage model of a RC column due to underwater explosion is a critical issue to assess the wharfs antiknock security.In this study,the dynamic response and damage model of circular RC columns subjected to underwater explosions were investigated by means of scaled-down experiment models.Experiments were carried out in a 10.0 m diameter tank with the water depth of 2.25 m,under different explosive quantities(0.025 kg-1.6 kg),stand-off distances(0.0 m-7.0 m),and detonation depths(0.25 m-2.0 m).The shock wave load and dynamic response of experiment models were measured by configuring sensors of pressure,acceleration,strain,and displacement.Then,the load distribution characteristics,time history of test data,and damage models related to present conditions were obtained and discussed.Three damage models,including bending failure,bending-shear failure and punching failure,were identified.In addition,the experie nce model of shock wave loads on the surface of a RC column was proposed for engineering application. 展开更多
关键词 Underwater explosion Reinforced concrete(RC)columns Load distribution characteristics dynamic response Damage models
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Test and numerical investigations on static and dynamic characteristics of extra-wide concrete self-anchored suspension bridge under vehicle loads 被引量:8
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作者 ZHOU Guang-pan LI Ai-qun +1 位作者 LI Jian-hui DUAN Mao-jun 《Journal of Central South University》 SCIE EI CAS CSCD 2017年第10期2382-2395,共14页
The present work is aimed at studying the mechanic properties of the extra-wide concrete self-anchored suspension bridge under static and dynamic vehicle loads. Based on the field test using 12 heavy trucks and finite... The present work is aimed at studying the mechanic properties of the extra-wide concrete self-anchored suspension bridge under static and dynamic vehicle loads. Based on the field test using 12 heavy trucks and finite element simulations, the static deformations of different components, stress increments and distributions of the girder, as well as the vibration characteristics and damping ratio of the Hunan Road Bridge were analyzed, which is the widest self-anchored suspension bridge in China at present. The dynamic responses were calculated using the Newmark-β integration method assisted by the simulation models of bridge and vehicles, the influences on the dynamic impact coefficient(DIC) brought by the vehicle parameters, girder width, eccentricity travel and deck flatness were also researched. The spatial effect of the girder is obvious due to the extra width, which performs as the stress increments distribute unevenly along the transverse direction, and the girder deflections and stress increments of the upper plate change as a "V" and "M" shape respectively under the symmetrical vehicle loads affected by the shear lag effect, cross slope and local effect of the wheels, the maximum of stress increments are located in the junctions with the inner webs. The obvious girder torsional deformation and the apparent unevenness of the hanger forces between the two cable planes under the eccentric vehicle loads, together with the mode shapes such as the girder transverse bending and torsion which appear relatively earlier, all reflect the weakened torsional rigidity of the extra-wide girder. The transverse displacements of towers are more obvious than the longitudinal ones. As for the influences on the DIC, the static effect of the heavier vehicles plays a major role when pass through with a higher speed and the changes of vehicle suspension stiffness generate greater impacts than the suspension damp. The values of DIC in the vehicle-running side during the eccentric travel, affected by the restricts from the static effects of the eccentric moving trucks, are significantly smaller than the vehicle-free side, the increase in the road roughness is the most sensitive one among the above influential factors. The results could provide references for the design, static and dynamic response analysis of the similar extra-wide suspension bridges. 展开更多
关键词 self-anchored suspension bridge extra-wide girder field test simulation vehicle loads increments distribution damping ratio mode shape dynamic impact coefficient
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Experimental and numerical simulation of air distribution and microorganism pollutant dispersion in gymnasium
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作者 马飞 霍廖然 +1 位作者 谢慧 范慧芳 《Journal of Central South University》 SCIE EI CAS 2009年第S1期38-42,共5页
By conducting experimental measurements and numerical simulations of air distribution and microorganism pollutant distribution in the auditorium and game area in a gymnasium,pollutant dispersion control and indoor air... By conducting experimental measurements and numerical simulations of air distribution and microorganism pollutant distribution in the auditorium and game area in a gymnasium,pollutant dispersion control and indoor air quality improvement methods were put forward. The results show that the fungi and bacteria concentration levels are less than the magnitude of 103 CFU (colony-forming units) which meets the requirements of indoor air quality standard. The numerical simulation results quantitatively agree with the experimental data while some differences between theoretical data and experimental data exist in air distributions. People number in gymnasium plays an important role in affecting indoor air quality and the environmental parameters attained the standard. 展开更多
关键词 air distribution MICROORGANISM POLLUTANT COMPUTATIONAL FLUID dynamics (CFD) EXPERIMENTAL
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面向动态混合数据的多粒度增量特征选择算法 被引量:1
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作者 王锋 姚珍 梁吉业 《软件学报》 北大核心 2025年第3期1186-1201,共16页
在大数据时代,样本规模以及维数的动态更新和变化极大地增加了计算负担,在这些动态数据中,大多的数据样本并不以单一的数据取值形式存在,而是同时包含符号型数据和数值型数据的混合型数据.为此,学者们提出了许多关于混合数据的特征选择... 在大数据时代,样本规模以及维数的动态更新和变化极大地增加了计算负担,在这些动态数据中,大多的数据样本并不以单一的数据取值形式存在,而是同时包含符号型数据和数值型数据的混合型数据.为此,学者们提出了许多关于混合数据的特征选择算法,但现有的算法大多只适用静态数据或者小规模的增量数据,无法处理大规模动态变化的数据,尤其是数据分布不断变化的大规模增量数据集.针对这一局限性,通过分析动态数据中粒空间以及粒结构的变化和更新,基于信息融合机制,提出了一种面向动态混合数据的多粒度增量特征选择算法.该算法重点讨论了动态混合数据中的粒空间构建机制、多数据粒结构的动态更新机制以及面向数据分布变化信息融合机制.最后,通过与其他算法在UCI数据集上的实验结果进行对比,进一步验证了所提算法的可行性和高效性. 展开更多
关键词 动态混合数据 数据分布变化 多粒度计算 信息融合
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面向啮合接触的斜齿轮修形多目标优化研究 被引量:1
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作者 周微 张全民 《机械设计与制造》 北大核心 2025年第1期374-379,384,共7页
以齿轮啮合接触分析为研究对象,提出了一种既能减振降噪又能使齿面载荷均匀分布的多目标优化设计方法。通过传输误差幅值的对比实验与理论计算,验证了载荷齿面接触分析模型的正确性。在此基础上,给出了齿面载荷分布的计算方法,并进一步... 以齿轮啮合接触分析为研究对象,提出了一种既能减振降噪又能使齿面载荷均匀分布的多目标优化设计方法。通过传输误差幅值的对比实验与理论计算,验证了载荷齿面接触分析模型的正确性。在此基础上,给出了齿面载荷分布的计算方法,并进一步提出了齿面载荷均匀分布的判断方法。以扭转方向相对速度最小和齿面载荷均匀分布为优化目标,构造多目标优化函数,得到最优修形参数。在此基础上给出了实例来说明所提出的方法,结果表明优化后沿扭转方向相对速度和左右齿面载荷差得到了大幅降低,验证了优化后的修形效果。 展开更多
关键词 载荷分配 修形 斜齿轮 动力特性 多目标优化
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新疆棉田花蓟马消长规律及空间分布
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作者 王伟 张仁福 +2 位作者 刘海洋 李晓维 姚举 《新疆农业科学》 北大核心 2025年第1期202-209,共8页
【目的】研究棉田花蓟马种群消长动态及空间分布型。【方法】采用五点取样法进行田间取样;利用广义线性混合模型分析棉株叶片、花和棉铃上花蓟马种群动态;应用5种聚集度指标和Taylor幂法则分析棉田花蓟马的空间分布型。【结果】棉田花... 【目的】研究棉田花蓟马种群消长动态及空间分布型。【方法】采用五点取样法进行田间取样;利用广义线性混合模型分析棉株叶片、花和棉铃上花蓟马种群动态;应用5种聚集度指标和Taylor幂法则分析棉田花蓟马的空间分布型。【结果】棉田花蓟马种群数量从6月中旬至7月上中旬逐渐上升,7月中下旬至8月中旬达到高峰,8月下旬后至9月初逐渐下降直至消失。花蓟马种群数量在棉花的叶片、花和棉铃上存在显著性差异,种群随着调查时间的变化而波动,且种群随时间变化而波动在不同器官之间也存在显著性差异。在花蓟马种群的初始增长期、爆发高峰期、下降期及全时期中,花上具有最高的花蓟马种群数量。花蓟马在棉田的空间分布型为聚集分布,且聚集度具有密度依赖性。【结论】7月中下旬至8月中旬是棉田花蓟马种群爆发期,其种群在棉田成聚集分布,且主要聚集于棉株花中。 展开更多
关键词 花蓟马 棉花 消长规律 空间分布
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计入冲击与摩擦的齿轮副传动特性研究 被引量:1
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作者 何泽银 裴世丰 +2 位作者 杨金 伍宏健 易锋 《机床与液压》 北大核心 2025年第1期1-8,共8页
为揭示啮合冲击与摩擦对齿轮副传动特性的影响规律,基于啮入冲击理论提出一种受载齿轮副转速计算方法,准确求解齿轮副时变转速变化情况。构建齿轮副啮入冲击数学模型,结合势能法得到线外啮合刚度,进而确定啮合齿对的齿面载荷。根据齿面... 为揭示啮合冲击与摩擦对齿轮副传动特性的影响规律,基于啮入冲击理论提出一种受载齿轮副转速计算方法,准确求解齿轮副时变转速变化情况。构建齿轮副啮入冲击数学模型,结合势能法得到线外啮合刚度,进而确定啮合齿对的齿面载荷。根据齿面油膜润滑状态,计算时变摩擦因数和摩擦力。最后,建立时变转速解析计算模型,阐明受载齿轮副转速周期性变化机制,并对齿轮副进行动态接触有限元分析。结果表明:线外啮合阶段主动轮转速呈先增大后减小的变化规律,从动轮转速突增,之后非线性减小;线内啮合阶段,主从动轮转速在理论值附近波动且波动幅值较小。数值分析与解析计算结果良好吻合,验证了解析算法的合理性。 展开更多
关键词 传动特性 啮入冲击 齿面摩擦 载荷分配 动态接触
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动态需求情形下多行程多交货期的成品油配送优化
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作者 谢勇 高海龙 +1 位作者 陈于涛 王焕江 《系统仿真学报》 北大核心 2025年第8期2016-2029,共14页
在动态需求情形下,综合考虑订单交货期、车辆运输时间窗等因素,以最大化配送收益为目标,建立了多行程多交货期的成品油周期性配送优化模型,并设计了基于强化学习的大邻域搜索算法进行求解。基于前向插入启发式算法构造初始解;设计了面... 在动态需求情形下,综合考虑订单交货期、车辆运输时间窗等因素,以最大化配送收益为目标,建立了多行程多交货期的成品油周期性配送优化模型,并设计了基于强化学习的大邻域搜索算法进行求解。基于前向插入启发式算法构造初始解;设计了面向邻域算子选择的深度强化学习模型,通过双深度Q网络拟合动作价值函数,以选择最优的邻域操作算子,获得最优配送方案。实验结果表明:基于强化学习的大邻域搜索算法能够在保证求解质量的同时有效提升求解速度。 展开更多
关键词 成品油配送 动态需求 多行程 多交货期 强化学习
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面向负荷灵活转供的雪花型配电网动态重构模型与方法
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作者 王哲 段佳莉 +1 位作者 罗凤章 吴璇 《电力系统及其自动化学报》 北大核心 2025年第5期121-130,共10页
针对城市电网负荷时空分布不均衡、负载波动大等问题,提出一种应用于雪花型配电网旨在实现负荷灵活转供的多阶段动态重构模型。首先,构建雪花型配电网的拓扑模型与潮流模型;然后,以负载均衡度和有功功率损耗最小为目标,建立考虑分布式... 针对城市电网负荷时空分布不均衡、负载波动大等问题,提出一种应用于雪花型配电网旨在实现负荷灵活转供的多阶段动态重构模型。首先,构建雪花型配电网的拓扑模型与潮流模型;然后,以负载均衡度和有功功率损耗最小为目标,建立考虑分布式电源和电储能的雪花型配电网多时段动态重构模型;接着,基于凸松弛理论将动态重构的非凸模型转化为混合整数二阶锥规划模型并求解;最后,通过实际电网验证所提模型和方法的有效性。结果表明,基于雪花型网架的配电网动态网络重构可有效利用馈线组的负荷转移能力,均衡轻重载主变和线路负荷,提高电网运行的安全性和经济性。 展开更多
关键词 雪花配电网 负荷转供 动态重构 二阶锥
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不平整积水道面条件下飞机着陆性能
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作者 蔡靖 刘知昊 +2 位作者 毛鹏飞 李岳 戴轩 《科学技术与工程》 北大核心 2025年第20期8725-8736,共12页
为解决飞机在积水道面着陆滑跑时遇到的安全问题,通过建立不同平整度等级的三维随机不平整半幅道面,利用积水分布特征矩阵的方法研究了跑道不平整影响下的着陆带积水分布。并且建立积水跑道飞机着陆滑跑理论模型,使用Simulink工具进行... 为解决飞机在积水道面着陆滑跑时遇到的安全问题,通过建立不同平整度等级的三维随机不平整半幅道面,利用积水分布特征矩阵的方法研究了跑道不平整影响下的着陆带积水分布。并且建立积水跑道飞机着陆滑跑理论模型,使用Simulink工具进行动力学仿真,分析在不同积水分布条件下跑道对飞机着陆性能影响。结果表明:平整度评级“差”(国际平整度指数international roughness index,IRI=5)相比平整度评级“好”(IRI=1)的跑道着陆滑跑距离增加约29 m,相比理想平整道面着陆距离增加了3.7%,且道面平整度降低会导致轮胎滑水风险加剧;若飞机接地速度从62 m/s提升到82 m/s,着陆距离将直接增加约520 m,增加了约87%;降雨强度1 mm/min相较干燥跑道的着陆滑跑距离增加了约20%,降雨强度从1 mm/min提升至3 mm/min的情况下,降雨强度每增加1 mm/min着陆距离增加6.5 m和7.4 m。可见道面不平整位置处,接地速度越大,则到达同一位置时的速度也越大,该位置附着系数降低幅度也越大,最大可达11.3%。随着降雨强度的增大,附着系数逐渐降低,降雨强度达到3 mm/min时,附着系数较干燥道面降低约20%。 展开更多
关键词 积水分布 动力学模型 接地速度 着陆距离 附着系数
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