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测定金刚石膜断裂强度及断裂韧性的力控制法研究 被引量:3
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作者 蔡增伸 蒋政 +1 位作者 王从贤 王海勇 《浙江工业大学学报》 CAS 2000年第3期216-219,共4页
人造金刚石膜是一种新材料。断裂强度及断裂韧性是其主要力学性能指标 ,目前国内、外尚无相应的强度测试方法标准 ,一般采用类比陶瓷测定断裂强度与断裂韧性的方法进行 ,即采用位移控制法进行检测。基于金刚石膜是一种硬度比陶瓷更高的... 人造金刚石膜是一种新材料。断裂强度及断裂韧性是其主要力学性能指标 ,目前国内、外尚无相应的强度测试方法标准 ,一般采用类比陶瓷测定断裂强度与断裂韧性的方法进行 ,即采用位移控制法进行检测。基于金刚石膜是一种硬度比陶瓷更高的材料 ,本文首次对金刚石膜提出用一种力控制法进行检测。在试验时采用专用的弹性压力头加载 ,加载速度可调 ,加载平稳、可靠 ,收到了很好的效果。 展开更多
关键词 金刚石膜 断裂强度 断裂韧性 力控制法 测定
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测定金刚石膜断裂强度及断裂韧性的力控制法研究 被引量:2
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作者 蔡增伸 蒋政 +1 位作者 王从贤 王海勇 《实验力学》 CSCD 北大核心 2001年第1期100-104,共5页
人造金刚石膜是一种新材料 .断裂强度及断裂韧性是其主要力学性能指标 ,目前国内、外尚无相应的强度测试方法标准 ,一般采用类比陶瓷测定断裂强度与断裂韧性的方法进行 ,即采用位移控制法进行检测 .基于金刚石膜是一种硬度比陶瓷更高的... 人造金刚石膜是一种新材料 .断裂强度及断裂韧性是其主要力学性能指标 ,目前国内、外尚无相应的强度测试方法标准 ,一般采用类比陶瓷测定断裂强度与断裂韧性的方法进行 ,即采用位移控制法进行检测 .基于金刚石膜是一种硬度比陶瓷更高的材料 ,本文首次提出对金刚石膜用一种力控制法进行检测 .在试验时采用专用的弹性压力头加载 ,加载速度可调 ,加载平稳、可靠 。 展开更多
关键词 金刚石膜 断裂强度 断裂韧性 弹性压 力控制法
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治理地下水污染——水动力控制法
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《能源与节能》 2015年第8期65-65,共1页
水动力控制法是利用井群系统,通过抽水或向含水层注水,人为地改变地下水的水力梯度,从而将受污染水体与清洁水体分隔开来。根据井群系统布置方式的不同,水力控制法可分为上游分水岭法和下游分水岭法。
关键词 地下水污染 力控制法 治理 污染水体 梯度 布置方式 分水岭 含水层
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基于法向恒力跟踪的船板打磨轨迹在线调整方法
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作者 张政 刘鑫宇 +1 位作者 关靖添 习俊通 《船舶工程》 CSCD 北大核心 2023年第9期130-134,共5页
机器人对船板零件自由边进行打磨时,初始打磨轨迹基于船板零件的三维几何模型生成。由于该三维几何模型与实际的船板零件存在一定偏差且船板刚性较大,文章设计了基于法向恒力跟踪控制的机器人打磨轨迹在线动态调整方法以保证自由边打磨... 机器人对船板零件自由边进行打磨时,初始打磨轨迹基于船板零件的三维几何模型生成。由于该三维几何模型与实际的船板零件存在一定偏差且船板刚性较大,文章设计了基于法向恒力跟踪控制的机器人打磨轨迹在线动态调整方法以保证自由边打磨质量。通过力位感知技术实时采集机器人打磨工具与待打磨船板零件之间的接触力信息;基于重力补偿与法向力分解算法,建立法向恒力跟踪下基于位置的阻抗控制模型以实时修整机器人的打磨轨迹,使其实时跟踪待打磨零件自由边。仿真结果表明:该方法可以很好地实现打磨轨迹的在线动态调整,使得调整后的打磨轨迹能够满足要求,保证船板零件自由边的打磨质量。 展开更多
关键词 自由边打磨 向恒跟踪控制 阻抗控制模型
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基于可靠度理论的混凝土桥梁安全性评估方法研究 被引量:13
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作者 李文杰 侯天宇 +1 位作者 赵君黎 冯苠 《公路交通科技》 CAS CSCD 北大核心 2017年第4期87-92,共6页
通过分析我国公路桥梁设计规范承载能力设计表达式,提出了汽车荷载效应调整系数和抗力调整系数的概念,确定了不同破坏形式下在役混凝土桥梁安全性能评估表达式和目标可靠指标,建立了相应的可靠度评估方法。在此基础上,从便于工程应用的... 通过分析我国公路桥梁设计规范承载能力设计表达式,提出了汽车荷载效应调整系数和抗力调整系数的概念,确定了不同破坏形式下在役混凝土桥梁安全性能评估表达式和目标可靠指标,建立了相应的可靠度评估方法。在此基础上,从便于工程应用的角度出发,建立了基于不同需求的在役混凝土桥梁安全性能实用评估方法——基于"双控"思想的安全性实用评估方法,即抗力控制法和汽车荷载效应控制法,并通过工程实例验证了该方法的可行性。 展开更多
关键词 桥梁工程 混凝土桥梁 可靠度理论 安全性能评估 调整系数 力控制法 汽车荷载效应控制
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A Robust Reserve Scheduling Method Considering Asymmetrical Wind Power Distribution 被引量:2
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作者 Guanzhong Wang Qiaoyan Bian 《IEEE/CAA Journal of Automatica Sinica》 SCIE EI CSCD 2018年第5期961-967,共7页
Nowadays, limited predictability and controllability of wind power are regarded as some bottlenecks to wind generation integration with the power system. This paper introduces a robust reserve scheduling method, where... Nowadays, limited predictability and controllability of wind power are regarded as some bottlenecks to wind generation integration with the power system. This paper introduces a robust reserve scheduling method, where the spinning reserve allocation among conventional units is considered as well.The method applies to asymmetrical wind power distribution,and offers control on the degree of solution's conservatism by changing the robustness budget. Meanwhile, distributional information of wind power is represented by mean value and asymmetrical bounds. Furthermore, the model is converted into a deterministic programming problem with dual theory. Case studies for asymmetrically distributed wind power illustrate its effectiveness. 展开更多
关键词 Power system reserve scheduling ROBUST wind power.
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Nonlinear control for a class of hydraulic servo system 被引量:13
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作者 余宏 冯正进 王旭永 《Journal of Zhejiang University Science》 EI CSCD 2004年第11期1413-1417,共5页
The dynamics of hydraulic systems are highly nonlinear and the system may be subjected to non-smooth and discontinuous nonlinearities due to directional change of valve opening, friction, etc. Aside from the nonlinear... The dynamics of hydraulic systems are highly nonlinear and the system may be subjected to non-smooth and discontinuous nonlinearities due to directional change of valve opening, friction, etc. Aside from the nonlinear nature of hydraulic dynamics, hydraulic servo systems also have large extent of model uncertainties. To address these challenging issues, a robust state-feedback controller is designed by employing backstepping design technique such that the system output tracks a given signal arbitrarily well, and all signals in the closed-loop system remain bounded. Moreover, a relevant disturbance attenuation inequality is satisfied by the closed-loop signals. Compared with previously proposed robust controllers, this paper's robust controller based on backstepping recursive design method is easier to design, and is more suitable for implementation. 展开更多
关键词 Nonlinear system Electro hydraulic servo system Robust control BACKSTEPPING Lyapunov function
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Research on Dynamic Model's Building of Active Magnetic Suspension Systems 被引量:4
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作者 施建 颜国正 +1 位作者 李黎川 王坤东 《Journal of Donghua University(English Edition)》 EI CAS 2006年第3期131-135,共5页
An experimental method is introduced in this paper to build the dynamics of AMSS (the active magnetic suspension system), which doesn’t depend on system’s physical parameters. The rotor can be reliably suspended und... An experimental method is introduced in this paper to build the dynamics of AMSS (the active magnetic suspension system), which doesn’t depend on system’s physical parameters. The rotor can be reliably suspended under the unit feedback control system designed with the primary dynamic model obtained. Online identification in frequency domain is processed to give the precise model. Comparisons show that the experimental method is much closer to the precise model than the theoretic method based on magnetic circuit law. So this experimental method is a good choice to build the primary dynamic model of AMSS. 展开更多
关键词 active magnetic suspension feedback control dynamic model building experimental method
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Dynamic modelling of 2-DOF luffing mechanism with serial closed kinematic chains 被引量:2
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作者 ZHU Zhen-xin ZHU Jian-xin +1 位作者 KANG Hui-mei QIAN Huan-yun 《Journal of Central South University》 SCIE EI CAS CSCD 2021年第1期168-178,共11页
Luffing mechanism is a key component of the construction machinery.This paper proposes a two degree of freedom(2-DOF)luffing mechanism,which has one more pair of driving cylinders than the single DOF luffing mechanism... Luffing mechanism is a key component of the construction machinery.This paper proposes a two degree of freedom(2-DOF)luffing mechanism,which has one more pair of driving cylinders than the single DOF luffing mechanism,to improve the performance of the machinery.To establish the dynamic model of the 2-DOF luffing mechanism,firstly,we develop a hierarchical method to deduce the Jacobian matrix and Hessian matrix for obtaining the kinematics equations.Subsequently,we divide the luffing mechanism into six bodies considering actuators,and deduce the kinetic equations of each body by the Newton-Euler method.Based on the dynamic model,we simulate the luffing process.Finally,a prototype is built on a pile driver to validate the model.Simulations and experiments show that the dynamic model can reflect the dynamic properties of the proposed luffing mechanism.And the control strategy that the front cylinders retract first shows better mechanical behavior than the other two control strategies.This research provides a reference for the design and application of 2-DOF luffing mechanism on construction machinery.The modeling approach can also be applied to similar mechanism with serial closed kinematic chains,which allows to calculate the dynamic parameters easily and exactly. 展开更多
关键词 luffing mechanism dynamic model hierarchical method control strategy PROTOTYPE
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Adaptive terminal sliding mode control for high-order nonlinear dynamic systems 被引量:11
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作者 庄开宇 苏宏业 +1 位作者 张克勤 褚健 《Journal of Zhejiang University Science》 EI CSCD 2003年第1期58-63,共6页
An adaptive terminal sliding mode control (SMC) technique is proposed to deal with the tracking problem for a class of high-order nonlinear dynamic systems. It is shown that a function augmented sliding hyperplane can... An adaptive terminal sliding mode control (SMC) technique is proposed to deal with the tracking problem for a class of high-order nonlinear dynamic systems. It is shown that a function augmented sliding hyperplane can be used to develop a new terminal sliding mode for high-order nonlinear systems. A terminal SMC controller based on Lyapunov theory is designed to force the state variables of the closed-loop system to reach and remain on the terminal sliding mode, so that the output tracking error then converges to zero in finite time which can be set arbitrarily. An adaptive mechanism is introduced to estimate the unknown parameters of the upper bounds of system uncertainties. The estimates are then used as controller parameters so that the effects of uncertain dynamics can be eliminated. It is also shown that the stability of the closed-loop system can be guaranteed with the proposed control strategy. The simulation of a numerical example is provided to show the effectiveness of the new method. 展开更多
关键词 Terminal sliding mode control Finite time convergence Adaptive laws
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Numerical Analysis of Finite Deformation of Overbroken Rock Mass in Gob Area Based on Euler Model of Control Volume 被引量:10
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作者 LIU Wei-qun MIAO Xie-xing 《Journal of China University of Mining and Technology》 EI 2006年第3期245-248,共4页
The overbroken rock mass of gob areas is made up of broken and accumulated rock blocks compressed to some extent by the overlying strata. The beating pressure of the gob can directly affect the safety of mining fields... The overbroken rock mass of gob areas is made up of broken and accumulated rock blocks compressed to some extent by the overlying strata. The beating pressure of the gob can directly affect the safety of mining fields, formarion of road retained along the next goaf and seepage of water and methane through the gob. In this paper, the software RFPA'2000 is used to construct numerical models. Especially the Euler method of control volume is proposed to solve the simulation difficulty arising from plastically finite deformations. The results show that three characteristic regions occurred in the gob area: (1) a naturally accumulated region, 0-10 m away from unbroken surrounding rock walls, where the beating pressure is nearly zero; (2) an overcompacted region, 10-20 m away from unbroken walls, where the beating pressure results in the maximum value of the gob area; (3) a stable compaction region, more than 20 m away from unbroken walls and occupying absolutely most of the gob area, where the beating pressures show basically no differences. Such a characteristic can exolain the easy-seeoaged “O”-ring phenomena around mining fields very well. 展开更多
关键词 overbroken rock mass plastically finite deformation method of control volume bearing pressure
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Parameter identification and pressure control of dynamic system in shield tunneling using least squares method 被引量:10
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作者 LI Shou-ju CAO Li-juan +1 位作者 SHANGGUAN Zi-chang LIU Bo 《Journal of Coal Science & Engineering(China)》 2010年第3期256-261,共6页
An estimation approach using least squares method was presented for identificationof model parameters of pressure control in shield tunneling.The state equation ofthe pressure control system for shield tunneling was a... An estimation approach using least squares method was presented for identificationof model parameters of pressure control in shield tunneling.The state equation ofthe pressure control system for shield tunneling was analytically derived based on themass equilibrium principle that the entry mass of the pressure chamber from cutting headwas equal to excluding mass from the screw conveyor.The randomly observed noise wasnumerically simulated and mixed to simulated observation values of system responses.The numerical simulation shows that the state equation of the pressure control system forshield tunneling is reasonable and the proposed estimation approach is effective even ifthe random observation noise exists.The robustness of the controlling procedure is validatedby numerical simulation results. 展开更多
关键词 parameter identification least squares method state equation shield tunneling
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Evaluation of Tourism Environmental Carrying Capacity of Pai Town-Medog County Hiking Route
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作者 WANG Zhongbin 《Journal of Landscape Research》 2018年第2期69-70,74,共3页
Based on the actual situation of Pai-Medog hiking route, the tourism environmental carrying capacity of this route was calculated in this study. According to the analysis and calculation results and referring to the c... Based on the actual situation of Pai-Medog hiking route, the tourism environmental carrying capacity of this route was calculated in this study. According to the analysis and calculation results and referring to the common control measures of tourism environmental carrying capacity, corresponding control measures were put forward for the Pai-Medog hiking route. 展开更多
关键词 Pai-Medog Tourist destination Environmental carrying capacity EVALUATION
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Closure technique for the hybrid girder cable stayed bridge of Edong Bridge
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作者 Liu Minghu Tan Hao +1 位作者 Xu GuoPing Zhao Canhui 《Engineering Sciences》 EI 2012年第4期51-56,共6页
Based on Edong Yangtze River Bridge, which is the second longest hybrid girder cable stayed bridge with 926 m long main span, the influencing factors and crucial techniques of the main span closure method for long spa... Based on Edong Yangtze River Bridge, which is the second longest hybrid girder cable stayed bridge with 926 m long main span, the influencing factors and crucial techniques of the main span closure method for long span hybrid girder cable stayed bridge are studied. After theoretical analysis, numerical evaluation and practical test, the loading assistant closure method is employed in Edong Yangtze River Bridge. The loading assistant closure method, with better thermal adaptability and less influence on bridge line and the forced status, can meet the requirements of the unstressed state control method. Based on the mentioned advantages, the loading assistant closure method is applicable to long span hybrid girder cable stayed bridges. The conclusion can provide a reference for the further design of the similar brid^es. 展开更多
关键词 Edong Bridge hybrid girder cable stayed bridge closure technique loading assistant closure method unstressed state control method
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High Precision Motion Control of Hybrid Five-Bar Mechanism with an Intelligent Control
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作者 张珂 王生泽 《Journal of Donghua University(English Edition)》 EI CAS 2009年第3期275-278,共4页
Hybrid mecihanism is a new type of planar controllable mechanism. Position control acouracy of system determines the output aconracy of the mechanism. In order to achieve the desired high acowacy, nonlinear factors as... Hybrid mecihanism is a new type of planar controllable mechanism. Position control acouracy of system determines the output aconracy of the mechanism. In order to achieve the desired high acowacy, nonlinear factors as friction nmst be accurately compensated in the real-time servo control algoritinn. In this paper, the model of a hybrid five-bar mechanism is introduced. In terms of the characteristics of the hybrid mechanism, a hybrid intelligent control algorithm based on proportional-integral-derivative (PID) control and cerebellar model articulation control techniques was presented and used to perform control of hybrid five-bar mechanism for the lust time. The sinmulation results show that the hybrid control method can improve the control effect remarkably, compared with the traditional PID control strategy. 展开更多
关键词 intelligent control systems h yybrid mechanism neural network proportional-integral-derivative (PID) control
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Control method for semi-active suspension based on virtual prototype
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作者 梁宇 《Journal of Chongqing University》 CAS 2005年第1期6-8,共3页
The simple dynamic model is often adopted to deal with control questions in research on semi-active suspension. The model has more theoretic meanings than authentic ones because of difference between practical and phy... The simple dynamic model is often adopted to deal with control questions in research on semi-active suspension. The model has more theoretic meanings than authentic ones because of difference between practical and physical models. The virtual prototype has remarkable advantages in its application simulation processes. It is not only faster and more veracious, but also of better visualization of the simulation results. 展开更多
关键词 semi-active suspension virtual prototype linear-quadratic regulator (LQR) control
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Modeling and analysis of moving-mass actuated stratospheric airship 被引量:1
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作者 周革 Chen Li Dong Qi 《High Technology Letters》 EI CAS 2013年第2期145-149,共5页
A moving-mass control method is introduced to stratospheric airship for its special working condition of low atmospheric density and low speed.The dynamic equation of airship is derived by using the Newton-Euler metho... A moving-mass control method is introduced to stratospheric airship for its special working condition of low atmospheric density and low speed.The dynamic equation of airship is derived by using the Newton-Euler method and the mechanism of attitude control by moving masses is studied.Then the passive gliding of airship by the moving masses is given based on the theory of glider,and attitude control capability between moving mass and elevator is compared at different airspeed.Analysis results show that the motion of masses changes the gravity center of the airship system,which makes the inertia tensor and the gravity moment vary.Meanwhile,the aerodynamic angles are generated,which results in the change of aerodynamic moment.Control efficiency of moving masses is independent of airspeed.Thus the moving-mass control has the advantage over the aerodynamic surfaces at low airspeed. 展开更多
关键词 stratospheric airship moving masses attitude control GLIDING control efficiency
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Data⁃Based Feedback Relearning Algorithm for Robust Control of SGCMG Gimbal Servo System with Multi⁃source Disturbance 被引量:3
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作者 ZHANG Yong MU Chaoxu LU Ming 《Transactions of Nanjing University of Aeronautics and Astronautics》 EI CSCD 2021年第2期225-236,共12页
Single gimbal control moment gyroscope(SGCMG)with high precision and fast response is an important attitude control system for high precision docking,rapid maneuvering navigation and guidance system in the aerospace f... Single gimbal control moment gyroscope(SGCMG)with high precision and fast response is an important attitude control system for high precision docking,rapid maneuvering navigation and guidance system in the aerospace field.In this paper,considering the influence of multi-source disturbance,a data-based feedback relearning(FR)algorithm is designed for the robust control of SGCMG gimbal servo system.Based on adaptive dynamic programming and least-square principle,the FR algorithm is used to obtain the servo control strategy by collecting the online operation data of SGCMG system.This is a model-free learning strategy in which no prior knowledge of the SGCMG model is required.Then,combining the reinforcement learning mechanism,the servo control strategy is interacted with system dynamic of SGCMG.The adaptive evaluation and improvement of servo control strategy against the multi-source disturbance are realized.Meanwhile,a data redistribution method based on experience replay is designed to reduce data correlation to improve algorithm stability and data utilization efficiency.Finally,by comparing with other methods on the simulation model of SGCMG,the effectiveness of the proposed servo control strategy is verified. 展开更多
关键词 control moment gyroscope feedback relearning algorithm servo control reinforcement learning multisource disturbance adaptive dynamic programming
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Optimization and Control of Extractive Distillation with Heat Integration for Separating Benzene/Cyclohexane Mixtures 被引量:3
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作者 Li Lumin Tu Yangqin +2 位作者 Guo Lianjie Sun Lanyi Tian Yuanyu 《China Petroleum Processing & Petrochemical Technology》 SCIE CAS 2016年第4期117-127,共11页
In this work, the extractive distillation with heat integration process is extended to separate the pressure-insensitive benzene-cyclohexane azeotrope by using furfural as the entrainer. The optimal design of extracti... In this work, the extractive distillation with heat integration process is extended to separate the pressure-insensitive benzene-cyclohexane azeotrope by using furfural as the entrainer. The optimal design of extractive distillation process is established to achieve minimum energy requirement using the multi-objective genetic algorithm, and the results show that energy saving for this heat integration process is 15.7%. Finally, the control design is performed to investigate the system's dynamic performance, and three control structures are studied. The pressure-compensated temperature control scheme is proposed based on the first two control structures, and the dynamic responses reveal that the feed disturbances in both flow rate and benzene composition can be mitigated well. 展开更多
关键词 extractive distillation heat integration optimization genetic algorithm dynamic simulation
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THE APPLICATION OF WALSHFUNCTIONS IN SYSTEM ANALYSIS
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作者 郝继飞 许世范 《Journal of China University of Mining and Technology》 1992年第1期56-65,共10页
In this paper,Waish functions are applied to dynamical system analysis. An operational matrix for differential is developed first and compared with M. S. Corrington's method vis a simple example. Then this operati... In this paper,Waish functions are applied to dynamical system analysis. An operational matrix for differential is developed first and compared with M. S. Corrington's method vis a simple example. Then this operational matrix is used to analyze both time-invariant and time-variant systems ,and examples are presented respectively. 展开更多
关键词 Walsh functions system analysis control theory
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