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SELF-RECONFIGURATION OF UNDERACTUATED REDUNDANT MANIPULATORS WITH OPTIMIZING THE FLEXIBILITY ELLIPSOID 被引量:4
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作者 HeGuangping LuZhen 《Chinese Journal of Mechanical Engineering》 SCIE EI CAS CSCD 2005年第1期92-97,共6页
The multi-modes feature, the measure of the manipulating flexibility, andself-reconfiguration control method of the underactuated redundant manipulators are investigatedbased on the optimizing technology. The relation... The multi-modes feature, the measure of the manipulating flexibility, andself-reconfiguration control method of the underactuated redundant manipulators are investigatedbased on the optimizing technology. The relationship between the configuration of the joint spaceand the manipulating flexibility of the underactuated redundant manipulator is analyzed, a newmeasure of manipulating flexibility ellipsoid for the underactuated redundant manipulator withpassive joints in locked mode is proposed, which can be used to get the optimal configuration forthe realization of the self-reconfiguration control. Furthermore, a time-varying nonlinear controlmethod based on harmonic inputs is suggested for fulfilling the self-reconfiguration. A simulationexample of a three-DOFs underactuated manipulator with one passive joint features some aspects ofthe investigations. 展开更多
关键词 Underactuated manipulators self-RECONFIGURATION optimIZATION Nonlinearcontrol
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OPTIMIZING DESIGN OF MECHANICAL SELF-CENTERING DEVICE FOR SUSPENSION HEIGHT 被引量:2
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作者 CAO Min ZHANG Yongchao YU Fan 《Chinese Journal of Mechanical Engineering》 SCIE EI CAS CSCD 2008年第6期69-75,共7页
Firstly, in view of the respective defects of existing self-centering devices for vehicle suspension height, the design scheme of the proposed mechanical self-centering device for suspension height is described. Takin... Firstly, in view of the respective defects of existing self-centering devices for vehicle suspension height, the design scheme of the proposed mechanical self-centering device for suspension height is described. Taking the rear suspension of a certain light bus as a research example, the structures and parameters of the novel device are designed and ascertained. Then, the road excitation models, the performance evaluation indexes and the half-vehicle model are built, the simulation outputs of time and frequency domain are obtained with the road excitations of random and pulse by using MATLAB/Simulink software. So the main characteristics of the self-centering suspension are presented preliminarily. Finally, a multi-objective parameter design optimization model for the self-centering device is built by weighted sum approach, and optimal solution is obtained by adopting complex approach. The relevant choosing-type parameters for self-centering device components are deduced by using discrete variable optimal method, and the optimal results are verified and analyzed. So the performance potentials of the self-centering device are exerted fully in condition of ensuring overall suspension performances. 展开更多
关键词 Suspension height self-CENTERING Vehicle height adjustment optimizing design Multi-objective optimization
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One-knob self-optimizing fuzzy control of CO_2 arc welding process
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作者 俞建荣 蒋力培 《中国有色金属学会会刊:英文版》 CSCD 2002年第6期1040-1045,共6页
A new one knob self optimizing fuzzy control system of CO 2 arc welding is established based on the synthetic performance evaluation of droplet transfer process. It includes two kinds of self optimizing fuzzy controll... A new one knob self optimizing fuzzy control system of CO 2 arc welding is established based on the synthetic performance evaluation of droplet transfer process. It includes two kinds of self optimizing fuzzy controllers: the arc voltage controller and the current waveform controller. The fuzzy control principle and the key points of the control patterns are presented. Through on line detecting, computing of characteristic parameters and one knob self optimizing adjusting, the characteristic parameters and welding variables can be adjusted to suitable ranges under the control of the arc voltage controller. Meanwhile the current waveform controller is active in the rear time stage of the short circuiting and the instant of re triggering arc. The experiment results show that the control and its algorithm can improve the synthetic performance of arc welding process apparently. 展开更多
关键词 二氧化碳电弧焊 自优化 模糊控制 智能控制
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Improved extracellular endo-1,4-β-mannosidase activity of recombinant Pichia pastoris by optimizing signal peptide 被引量:3
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作者 王冶 郑甲 +1 位作者 林福来 周洪波 《Journal of Central South University》 SCIE EI CAS CSCD 2015年第6期2088-2095,共8页
In order to improve the extracellular endo-1,4-β-mannosidase(MAN) activity of recombinant Pichia pastoris, optimization of signal peptides was investigated. At first, five potential signal peptides(W1, MF4 I, INU1 A,... In order to improve the extracellular endo-1,4-β-mannosidase(MAN) activity of recombinant Pichia pastoris, optimization of signal peptides was investigated. At first, five potential signal peptides(W1, MF4 I, INU1 A, αpre, HFBI) were chosen to be analyzed by Signal P 4.0, among which W1 was designed. Then, the widely used signal peptide α-factor in expression vector p GAPZαA was replaced by those five signal peptides to reconstruct five new expression vectors. MAN activity was assayed after expression vectors were transformed into Pichia pastoris. The data show that the relative efficiencies of W1, MF4 I, INU1 A, αpre, and HFBI signal peptides are 23.5%, 203.5%, 0, 79.7%, and 120.3% compared with α-factor, respectively. The further gene copy number determination by the quantitative real-time PCR reveals that the MAN activities mediated by α-factor from 1 to 6 gene copy number levels are 12.95, 43.33, 126.63, 173.53, 103.23 and 88.63 U/m L, while those mediated by MF4 I are 79.22, 133.89, 260.14, 347.5, 206.15 and 181.89 U/m L, respectively. The maximum MAN activity reached 347.5 U/m L with 4 gene copies mediated by MF4 I. These results indicate that replacing the signal peptide α-factor with MF4 I and increasing MAN gene copies to a proper number can greatly improve the secretory expression of MAN. 展开更多
关键词 endo-1 4-β-mannosidase Pichia pastoris (P.pastoris) signal peptide optimization
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Real-valued multi-area self set optimization in immunity-based network intrusion detection system 被引量:1
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作者 Zhang Fengbin Xi Liang Wang Shengwen 《High Technology Letters》 EI CAS 2012年第1期1-6,共6页
The real-valued self set in immunity-based network intrusion detection system (INIDS) has some defects: multi-area and overlapping, which are ignored before. The detectors generated by this kind of self set may hav... The real-valued self set in immunity-based network intrusion detection system (INIDS) has some defects: multi-area and overlapping, which are ignored before. The detectors generated by this kind of self set may have the problem of boundary holes between self and nonself regions, and the generation efficiency is low, so that, the self set needs to be optimized before generation stage. This paper proposes a self set optimization algorithm which uses the modified clustering algorithm and Gaussian distribution theory. The clustering deals with multi-area and the Gaussian distribution deals with the overlapping. The algorithm was tested by Iris data and real network data, and the results show that the optimized self set can solve the problem of boundary holes, increase the efficiency of detector generation effectively, and improve the system's detection rate. 展开更多
关键词 immunity-based network intrusion detection system (NIDS) real-valued self set optimIZATION
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Optimal design of self-propagating high temperature one-dimensional nano-SnO_2 synthesis 被引量:4
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作者 Nian LIU Guodonq ZHANG 《Acta Metallurgica Sinica(English Letters)》 SCIE EI CAS CSCD 2011年第4期321-325,共5页
The success in synthesizing high purity SnO2 nanobelts via self-propagating high tem- perature synthesis was achieved. According to the experimental results, a relationship between the residual heat of the reaction sy... The success in synthesizing high purity SnO2 nanobelts via self-propagating high tem- perature synthesis was achieved. According to the experimental results, a relationship between the residual heat of the reaction system at 2848 K and SnO2 nanobelts yield was identified. The most appropriate formula for this self-propagating high tempera- ture synthesis method is turned out to be composed of Sn powder and thermite with weight ratio of 1:1. 展开更多
关键词 optimal design self-propagating high temperature synthesis Nano-Sn02
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Prediction-based Manufacturing Center Self-adaptive Demand Side Energy Optimization in Cyber Physical Systems 被引量:4
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作者 SUN Xinyao WANG Xue +1 位作者 WU Jiangwei LIU Youda 《Chinese Journal of Mechanical Engineering》 SCIE EI CAS CSCD 2014年第3期488-495,共8页
Cyber physical systems(CPS) recently emerge as a new technology which can provide promising approaches to demand side management(DSM), an important capability in industrial power systems. Meanwhile, the manufactur... Cyber physical systems(CPS) recently emerge as a new technology which can provide promising approaches to demand side management(DSM), an important capability in industrial power systems. Meanwhile, the manufacturing center is a typical industrial power subsystem with dozens of high energy consumption devices which have complex physical dynamics. DSM, integrated with CPS, is an effective methodology for solving energy optimization problems in manufacturing center. This paper presents a prediction-based manufacturing center self-adaptive energy optimization method for demand side management in cyber physical systems. To gain prior knowledge of DSM operating results, a sparse Bayesian learning based componential forecasting method is introduced to predict 24-hour electric load levels for specific industrial areas in China. From this data, a pricing strategy is designed based on short-term load forecasting results. To minimize total energy costs while guaranteeing manufacturing center service quality, an adaptive demand side energy optimization algorithm is presented. The proposed scheme is tested in a machining center energy optimization experiment. An AMI sensing system is then used to measure the demand side energy consumption of the manufacturing center. Based on the data collected from the sensing system, the load prediction-based energy optimization scheme is implemented. By employing both the PSO and the CPSO method, the problem of DSM in the manufac^ring center is solved. The results of the experiment show the self-adaptive CPSO energy optimization method enhances optimization by 5% compared with the traditional PSO optimization method. 展开更多
关键词 cyber physical systems manufacturing center self-ADAPTIVE demand side management particle swarm optimization
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Enhanced self-adaptive evolutionary algorithm for numerical optimization 被引量:1
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作者 Yu Xue YiZhuang +2 位作者 Tianquan Ni Jian Ouyang ZhouWang 《Journal of Systems Engineering and Electronics》 SCIE EI CSCD 2012年第6期921-928,共8页
There are many population-based stochastic search algorithms for solving optimization problems. However, the universality and robustness of these algorithms are still unsatisfactory. This paper proposes an enhanced se... There are many population-based stochastic search algorithms for solving optimization problems. However, the universality and robustness of these algorithms are still unsatisfactory. This paper proposes an enhanced self-adaptiveevolutionary algorithm (ESEA) to overcome the demerits above. In the ESEA, four evolutionary operators are designed to enhance the evolutionary structure. Besides, the ESEA employs four effective search strategies under the framework of the self-adaptive learning. Four groups of the experiments are done to find out the most suitable parameter values for the ESEA. In order to verify the performance of the proposed algorithm, 26 state-of-the-art test functions are solved by the ESEA and its competitors. The experimental results demonstrate that the universality and robustness of the ESEA out-perform its competitors. 展开更多
关键词 self-ADAPTIVE numerical optimization evolutionary al-gorithm stochastic search algorithm.
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Self-adaptive strategy for one-dimensional finite element method based on EEP method with optimal super-convergence order 被引量:4
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作者 袁驷 邢沁妍 +1 位作者 王旭 叶康生 《Applied Mathematics and Mechanics(English Edition)》 SCIE EI 2008年第5期591-602,共12页
Based on the newly-developed element energy projection (EEP) method with optimal super-convergence order for computation of super-convergent results, an improved self-adaptive strategy for one-dimensional finite ele... Based on the newly-developed element energy projection (EEP) method with optimal super-convergence order for computation of super-convergent results, an improved self-adaptive strategy for one-dimensional finite element method (FEM) is proposed. In the strategy, a posteriori errors are estimated by comparing FEM solutions to EEP super-convergent solutions with optimal order of super-convergence, meshes are refined by using the error-averaging method. Quasi-FEM solutions are used to replace the true FEM solutions in the adaptive process. This strategy has been found to be simple, clear, efficient and reliable. For most problems, only one adaptive step is needed to produce the required FEM solutions which pointwise satisfy the user specified error tolerances in the max-norm. Taking the elliptical ordinary differential equation of the second order as the model problem, this paper describes the fundamental idea, implementation strategy and computational algorithm and representative numerical examples are given to show the effectiveness and reliability of the proposed approach. 展开更多
关键词 finite element method (FEM) self-adaptive solution super-convergence optimal convergence order element energy projection condensed shape functions
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Comprehensive Optimal Control on Seismic Response of a Single-Tower Self-Anchored Suspension Bridge 被引量:1
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作者 WANG Hao LI Aiqun JIAO Changke 《Wuhan University Journal of Natural Sciences》 CAS 2011年第1期55-63,共9页
Earthquake may cause severe damage to all kinds of bridge such as the falling down of the girder; therefore,effective measures should be employed to control the seismic displacement. In this paper,the method of compre... Earthquake may cause severe damage to all kinds of bridge such as the falling down of the girder; therefore,effective measures should be employed to control the seismic displacement. In this paper,the method of comprehensive optimal control,com-bined with analytic hierarchy process,is employed to investigate the seismic response control of the Nanjing Jiangxinzhou Bridge,which is a single-tower self-anchored suspension bridge (SSSB). Also,3-dimensional nonlinear seismic response analyses are con-ducted. Three types of practical connection measures for seismic response control of SSSB are investigated,and the optimal pa-rameters of the connection devices are achieved by this method. Results show that both the elastic connection devices and the damp-ers with rational parameters can reduce the seismic displacement of the bridge effectively,but the elastic connection devices will in-crease the seismic force of the tower. When all factors are consid-ered,the optimal measure is by using the elastic connection devices and the dampers together. These results can provide references for seismic response control of SSSBs. 展开更多
关键词 self-anchored suspension bridge (SSSB) seismic response comprehensive optimal control single tower analytic hierarchy process (AHP) method
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基于改进HHO-LSTM-Self-Attention的质子交换膜燃料电池剩余使用寿命预测 被引量:1
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作者 蒋剑 杜董生 苏林 《综合智慧能源》 2025年第6期47-56,共10页
质子交换膜燃料电池(PEMFC)在诸多领域有着广泛应用,但其性能衰退会降低功率输出和能源转换效率、缩短使用寿命,准确预测剩余使用寿命对维护系统、降低成本及保障供电稳定极为关键。基于PEMFC功率随时间的变化趋势,提出了一种结合改进... 质子交换膜燃料电池(PEMFC)在诸多领域有着广泛应用,但其性能衰退会降低功率输出和能源转换效率、缩短使用寿命,准确预测剩余使用寿命对维护系统、降低成本及保障供电稳定极为关键。基于PEMFC功率随时间的变化趋势,提出了一种结合改进的哈里斯鹰优化(HHO)算法、长短期记忆(LSTM)网络和自注意力(Self-Attention)机制的PEMFC剩余使用寿命预测模型。基于电流和电压数据关系得出时间-功率变化曲线,采用小波自适应去噪和指数平滑相结合的方法对时间-功率数据进行分解去噪和重构;针对LSTM训练参数过多、计算量大等不足,提出了一种Logistics混沌映射与HHO算法相结合来优化LSTM的方法,以提高模型的训练速度和预测精度;基于Self-Attention具有聚焦关键信息和提高模型训练准确率的优点,构建了HHO-LSTM-Self-Attention预测模型。试验结果表明,与HHO-LSTM,LSTM,麻雀搜索算法(SSA)-LSTM,粒子群优化(PSO)-LSTM等预测模型相比,该模型具有更高的预测精度。 展开更多
关键词 质子交换膜燃料电池 剩余使用寿命预测 哈里斯鹰优化算法 长短期记忆神经网络 自注意力机制
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Optimal design of RTCs in digital circuit fault self-repair based on global signal optimization
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作者 Zhang Junbin Cai Jinyan Meng Yafeng 《Chinese Journal of Aeronautics》 SCIE EI CAS CSCD 2016年第6期1774-1787,共14页
Since digital circuits have been widely and thoroughly applied in various fields, electronic systems are increasingly more complicated and require greater reliability. Faults may occur in electronic systems in complic... Since digital circuits have been widely and thoroughly applied in various fields, electronic systems are increasingly more complicated and require greater reliability. Faults may occur in electronic systems in complicated environments. If immediate field repairs are not made on the faults, electronic systems will not run normally, and this will lead to serious losses. The traditional method for improving system reliability based on redundant fault-tolerant technique has been unable to meet the requirements. Therefore, on the basis of(evolvable hardware)-based and(reparation balance technology)-based electronic circuit fault self-repair strategy proposed in our preliminary work, the optimal design of rectification circuits(RTCs) in electronic circuit fault self-repair based on global signal optimization is deeply researched in this paper. First of all, the basic theory of RTC optimal design based on global signal optimization is proposed. Secondly, relevant considerations and suitable ranges are analyzed. Then, the basic flow of RTC optimal design is researched. Eventually, a typical circuit is selected for simulation verification, and detailed simulated analysis is made on five circumstances that occur during RTC evolution. The simulation results prove that compared with the conventional design method based RTC, the global signal optimization design method based RTC is lower in hardware cost, faster in circuit evolution, higher in convergent precision, and higher in circuit evolution success rate. Therefore, the global signal optimization based RTC optimal design method applied in the electronic circuit fault self-repair technology is proven to be feasible, effective, and advantageous. 展开更多
关键词 Evolutionary algorithm Evolvable hardware Fault self-repair optimal design Reparation balance technology
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Particle Swarm Optimization Algorithm Based on Chaotic Sequences and Dynamic Self-Adaptive Strategy
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作者 Mengshan Li Liang Liu +4 位作者 Genqin Sun Keming Su Huaijin Zhang Bingsheng Chen Yan Wu 《Journal of Computer and Communications》 2017年第12期13-23,共11页
To deal with the problems of premature convergence and tending to jump into the local optimum in the traditional particle swarm optimization, a novel improved particle swarm optimization algorithm was proposed. The se... To deal with the problems of premature convergence and tending to jump into the local optimum in the traditional particle swarm optimization, a novel improved particle swarm optimization algorithm was proposed. The self-adaptive inertia weight factor was used to accelerate the converging speed, and chaotic sequences were used to tune the acceleration coefficients for the balance between exploration and exploitation. The performance of the proposed algorithm was tested on four classical multi-objective optimization functions by comparing with the non-dominated sorting genetic algorithm and multi-objective particle swarm optimization algorithm. The results verified the effectiveness of the algorithm, which improved the premature convergence problem with faster convergence rate and strong ability to jump out of local optimum. 展开更多
关键词 Particle SWARM Algorithm CHAOTIC SEQUENCES self-ADAPTIVE STRATEGY MULTI-OBJECTIVE optimization
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Edge-Federated Self-Supervised Communication Optimization Framework Based on Sparsification and Quantization Compression
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作者 Yifei Ding 《Journal of Computer and Communications》 2024年第5期140-150,共11页
The federated self-supervised framework is a distributed machine learning method that combines federated learning and self-supervised learning, which can effectively solve the problem of traditional federated learning... The federated self-supervised framework is a distributed machine learning method that combines federated learning and self-supervised learning, which can effectively solve the problem of traditional federated learning being difficult to process large-scale unlabeled data. The existing federated self-supervision framework has problems with low communication efficiency and high communication delay between clients and central servers. Therefore, we added edge servers to the federated self-supervision framework to reduce the pressure on the central server caused by frequent communication between both ends. A communication compression scheme using gradient quantization and sparsification was proposed to optimize the communication of the entire framework, and the algorithm of the sparse communication compression module was improved. Experiments have proved that the learning rate changes of the improved sparse communication compression module are smoother and more stable. Our communication compression scheme effectively reduced the overall communication overhead. 展开更多
关键词 Communication optimization Federated self-Supervision Sparsification Gradient Compression Edge Computing
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Optimal Deployment with Self-Healing Movement Algo-rithm for Particular Region in Wireless Sensor Network
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作者 Fan ZHU Hongli LIU +1 位作者 Shugang LIU Jie ZHAN 《Wireless Sensor Network》 2009年第3期212-221,共10页
Optimizing deployment of sensors with self-healing ability is an efficient way to solve the problems of cov-erage, connectivity and the dead nodes in WSNs. This work discusses the particular relationship between the m... Optimizing deployment of sensors with self-healing ability is an efficient way to solve the problems of cov-erage, connectivity and the dead nodes in WSNs. This work discusses the particular relationship between the monitoring range and the communication range, and proposes an optimal deployment with self-healing movement algorithm for closed or semi-closed area with irregular shape, which can not only satisfy both coverage and connectivity by using as few nodes as possible, but also compensate the failure of nodes by mobility in WSNs. We compute the maximum efficient range of several neighbor sensors based on the dif-ferent relationships between monitoring range and communication range with consideration of the complex boundary or obstacles in the region, and combine it with the Euclidean Minimum Spanning Tree (EMST) algorithm to ensure the coverage and communication of Region of Interest (ROI). Besides, we calculate the location of dead nodes by Geometry Algorithm, and move the higher priority nodes to replace them by an-other Improved Virtual Force Algorithm (IVFA). Eventually, simulation results based-on MATLAB are presented, which do show that this optimal deployment with self-healing movement algorithm can ensure the coverage and communication of an entire region by requiring the least number of nodes and effectively compensate the loss of the networks. 展开更多
关键词 optimal DEPLOYMENT self-HEALING MOVEMENT PARTICULAR REGION Euclidean Minimum SPANNING Tree (EMST) Improved Virtual Force Algorithm (IVFA)
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Mixed Self-adapting GA Optimal Scheduling Algorithm for a Multiple Resource Job-shop
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作者 LI Shu-juan LI Yan LIU Zhi-gang 《International Journal of Plant Engineering and Management》 2007年第3期160-170,共11页
With an aim at the job-shop scheduling problem of multiple resource constraints, this paper presents mixed self-adapting Genetic Algorithm ( GA ) , and establishes a job-shop optimal scheduling model of multiple res... With an aim at the job-shop scheduling problem of multiple resource constraints, this paper presents mixed self-adapting Genetic Algorithm ( GA ) , and establishes a job-shop optimal scheduling model of multiple resource constraints based on the effect of priority scheduling rules in the heuristic algorithm upon the scheduling target. New coding regulations or rules are designed. The sinusoidal function is adopted as the self-adapting factor, thus making cross probability and variable probability automatically change with group adaptability in such a way as to overcome the shortcoming in the heuristic algorithm and common GA, so that the operation efficiency is improved. The results from real example simulation and comparison with other algorithms indicate that the mixed self-adapting GA algorithm can well solve the job-shop optimal scheduling problem under the constraints of various kinds of production resources such as machine-tools and cutting tools. 展开更多
关键词 heuristic rule mixed self-adapting GA multiple resource constraint optimal scheduling
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基于PSO-BP的自平衡法试桩技术平衡点位置研究 被引量:2
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作者 欧孝夺 梁枫 江杰 《广西大学学报(自然科学版)》 北大核心 2025年第2期231-241,共11页
针对自平衡法静载试验在灰岩地区应用较少,且工程中常用规范经验公式来确定平衡点位置存在较大误差的问题,提出以桩长、桩径、土层弹性模量为输入参数,构建PSO-BP神经网络平衡点位置的预测模型。通过将仿真预测值与真实值进行对比,并结... 针对自平衡法静载试验在灰岩地区应用较少,且工程中常用规范经验公式来确定平衡点位置存在较大误差的问题,提出以桩长、桩径、土层弹性模量为输入参数,构建PSO-BP神经网络平衡点位置的预测模型。通过将仿真预测值与真实值进行对比,并结合工程实例来验证本模型的适用性。结果表明,结合粒子群算法优化的PSO-BP神经网络模型,其平衡点位置预测值与真实值的平均相对误差控制在1.93%以内,而BP神经网络的平衡点位置预测值平均相对误差最高可达14.83%;依托来宾市当地以灰岩为持力层的工程试桩数据构建的PSO-BP神经网络平衡点位置预测模型,其仿真预测结果的均方根误差(R_(MSE))为0.294,决定系数R^(2)为0.988,预测值与真实值的相对误差在3.0%以内;在工程实例的对比验证中,PSO-BP神经网络模型在平衡点位置预测上的精度高于规范经验公式法,更接近实际位置,可作为灰岩地区基桩自平衡试桩测试的平衡点位置确定的有效手段。 展开更多
关键词 自平衡法 平衡点 粒子群优化-反向传播神经网络 粒子群算法 灰岩
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优选论理论下英语“X-self”和汉语“自己”的对比研究
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作者 丁冉 《长春大学学报》 2009年第9期34-36,共3页
英语"X-self"和汉语"自己"都可以出现在宾语语域,但二者在充当宾语时所表现出来的约束性不同。在优选论指导下,制定了二者在句型"NP1+V1P1(PP1)+NP2+V2P2+R"中的约束等级,并考察了影响二者约束性的各种... 英语"X-self"和汉语"自己"都可以出现在宾语语域,但二者在充当宾语时所表现出来的约束性不同。在优选论指导下,制定了二者在句型"NP1+V1P1(PP1)+NP2+V2P2+R"中的约束等级,并考察了影响二者约束性的各种因素之间的关系。结果表明:英语"X-self"的约束等级和汉语"自己"的约束等级既含有不同的原则也含有相同的原则;正是由于不同的原则,造成了在英语和汉语中句法结构完全相同的句子而二者约束性的不同。 展开更多
关键词 X-self 自己 优选论 约束
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基于IMLZC和SOA-ELM的轴承损伤识别方法 被引量:1
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作者 龙有强 姜峰 《机电工程》 北大核心 2025年第4期726-734,共9页
现有故障诊断方法大多是仅针对轴承故障类型进行分析,而缺少对故障程度进行相应的判断。为此,提出了一种基于改进多尺度Lempel-Ziv复杂度(IMLZC)和海鸥优化算法优化极限学习机(SOA-ELM)的滚动轴承损伤识别方法。首先,利用IMLZC复杂度测... 现有故障诊断方法大多是仅针对轴承故障类型进行分析,而缺少对故障程度进行相应的判断。为此,提出了一种基于改进多尺度Lempel-Ziv复杂度(IMLZC)和海鸥优化算法优化极限学习机(SOA-ELM)的滚动轴承损伤识别方法。首先,利用IMLZC复杂度测量指标对信号复杂度变化敏感的特点,将其用于提取滚动轴承振动信号的故障特征以构造特征矩阵;然后,利用海鸥优化算法对极限学习机(ELM)的关键参数进行了优化,建立了参数自适应优化的ELM分类模型;最后,将故障特征输入至SOA-ELM分类模型中进行了训练和测试,完成了滚动轴承不同故障状态的智能诊断和故障程度评估,利用滚动轴承和自吸式离心泵损伤振动信号对IMLZC-SOA-ELM模型的实用性和泛化性开展了研究,并将其与其他特征提取模型开展了对比。研究结果表明:基于IMLZC-SOA-ELM的故障诊断方法不仅能够准确识别滚动轴承的故障,而且能判断故障的严重程度,该故障诊断模型在诊断滚动轴承的故障时分别取得了100%和98.4%的识别准确率,平均识别准确率达到了99.9%,能够有效识别滚动轴承的故障类型和故障程度。与其他特征提取方法相比,IMLZC-SOA-ELM模型具有更高的识别准确率,更适合于滚动轴承的故障识别。 展开更多
关键词 滚动轴承 自吸式离心泵 故障诊断 故障程度和损伤程度 改进多尺度Lempel-Ziv复杂度 海鸥优化算法 参数最优极限学习机
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基于局部self-concordant障碍函数的全牛顿步多项式时间算法(英文) 被引量:1
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作者 金正静 白延琴 韩伯顺 《运筹学学报》 CSCD 北大核心 2008年第1期1-15,共15页
由Nesterov和Nemirovski^([4])创立的self-concordant障碍函数理论为解线性和凸优化问题提供了多项式时间内点算法.根据self-concordant障碍函数的参数,就可以分析内点算法的复杂性.在这篇文章中,我们介绍了基于核函数的局部self-concor... 由Nesterov和Nemirovski^([4])创立的self-concordant障碍函数理论为解线性和凸优化问题提供了多项式时间内点算法.根据self-concordant障碍函数的参数,就可以分析内点算法的复杂性.在这篇文章中,我们介绍了基于核函数的局部self-concordant障碍函数,它在线性优化问题的中心路径及其邻域内满足self-concordant性质.通过求解此障碍函数的局部参数值,我们得到了求解线性规划问题的基于此局部Self-concordant障碍函数的纯牛顿步内点算法的理论迭代界.此迭代界与目前已知的最好的理论迭代界是一致的. 展开更多
关键词 运筹学 线性规划 障碍函数 self-concordant函数 内点算法 多项式时间算法
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