An Improved Method of the Transient Waveform Analysis in Power Systems     

Wang Jianping Mi Linshu Chen Gang 《保鲜与加工》1993,(6):32-37

The angular frequency and decaying constant of each copmonect for the transient waveform in power systems were obtained by using the discrete Fourier transform; the amplitude and phase angle were calculated in the linear curve fitting method. And all of the parameters obtained above were treated in an unified optimization by using the curve fitting optimization of the least square method of general nonlinear funcrion so as to get the results of waveform analysis. Two examples are included.  相似文献   

Analysis and FEM Simulation of the Forming Process of Front Bumper Bracket     

ZHOU Jie  ZHANG Yu-ping  WEI Guang-zhen  YANG De-sen 《保鲜与加工》2007,(7):14-17

The processing characteristics of the front bumper bracket are analyzed,and a reasonable process scheme is worked out.The three-dimensional sheet metal forming analysis software PAM-STAMP are adopted to simulate the bracket's drawing process.Then the surface of die is proved fine through analyzing the FLD diagrams and the forming results.An economical and optimized die structure is decided,and a complete set of dies of the bracket is designed.The spacing block is added in the sizing mold,which control the size precision of end products and assembling columns actively,and finally the certified products.The material utility and the labor productivity are raised,the production cost is saved,and the mold design quality and the efficiency are improved effectively.  相似文献   

AN ACCELERATION SEARCH METHOD FOR UNCONSTRAINED OPTIMIZATION AND ITS APPLICATION IN MODEL PARAMETER ESTIMATION     

Sun Dihua Yang Yongzhen 《保鲜与加工》1991,(6):62-68

In order to improve the convergence rate of the algorithms, an acceleration search method along a straight or curve is proposed,and the specific calculation steps of the algorithms are presented. The numerical results in model parameter estimation show that the convergence rate is improved and the calculation accords with the practical demands.  相似文献   

The Optimal Method of Deep Development Stretching of Multi-levels Complex Mine     

Xu Yingfu 《保鲜与加工》1994,(5):132-136

  相似文献   

Physical simulation of fluid field and structure optimization in two-strand tundish     

LI Guangqiang  FU Yong  CHEN Xianhong  ZHANG Zhan  RAO Jiangping  YANG Zhizheng 《保鲜与加工》2015,(2):64-71

The influence of the structure and location of dam and weir on fluid flow state in a two-strand tundish is studied, and a set of optimal structure, combining with the average residence time calculated from RTD curve, is obtained. The result indicates that the fluid flow state can be changed and the path of the fluid flow can be prolonged as well as the average residence time is improved after using dam and weir. But there are some dead zones after fluid passed through the dam and weir. Combination scheme of No. one dam and weir is better than the others. Its average residence time is 299 s and the volume fraction of dead zone is 31.0%. After the optimization of flowing control parameters in tundish, the best case is that the distance between dam and weir is 290 mm and the distance between weir and the long nozzle is 383 mm. The longest average residence time is 351 s and the minimum volume fraction of dead zone is 19.0% under the above situation. Compared with that of no dam and weir, the average residence time increases by 65 s and the dead zone volume fraction decreases by 15.0%. Based on Newton formula, the calculated results show that the inclusions with diameter larger than 17.5 μm can float up within 351 s under this optimization situation.  相似文献   

Analysis on Limitation of Present Urban Planning in China     

LU Feng  HE Xin 《保鲜与加工》2006,(2):11

In urban design, only by continuous and dynamic research work from design to finally putting it into practice, can we made good control on city appearance. This article analyzes nowadays defects in our urban design from two aspects as the result establishment and validated control, and tries to conceive a feasibility plan to solve the problem.  相似文献   

Influence Mechanism of Matching on Human-information System Interactive Efficiency Within Enterprise Computerization Environment     

CHEN Feng  YI Shu-ping  YANG Wen-cai  WANG Hai-xia 《保鲜与加工》2007,(10):36-41

  相似文献   

Optimization of Energy Dissipation Braces in Frame Structures     

WU Ze hou  ZHOU Fu lin 《保鲜与加工》2002,(2):47

In this paper, the complex method of the nonlinear programming is used to optimize the parameters of energy dissipation bracing in energy dissipation braced frame. This method is realized with computer program and proved to be efficient. A 6-story reinforced concrete frame is used as a demonstrative example.  相似文献   

Enterprise Information Engineering Model and Its Integrated Support Environment     

TAN Wen-an 《保鲜与加工》2004,(12):73-77

By analyzing the process of enterprise information engineering construction and intra relationship among information system requirement, business process modeling, application system constructing and project management, one of 4 meta model composed of requirement engineering, process engineering, application system engineering and support engineering is proposed for enterprise information engineering. The developments and applications of the business processes and its application systems are integrated into the same development space and application space. Basing on this, a prototype system composed of requirement modeling environment, business process modeling environment, application system modeling environment, and support engineering environment has been designed and built, which is used for supporting enterprise information engineering constructing. It is valued for the enterprise information engineering construction in our country.  相似文献   

Optimization of Curve Fitting Used in Development of Magic Formula Tire Model     

REN Guang-sheng 《保鲜与加工》2001,(3):22-25

Characteristics of a tire are the foundation of vehicle dynamics studying, especially play a vital role in vehicle handling study. It is necessary to establish a tire model in the simulation for vehicle handling because the tire characteristics got by test can not be satisfied.The optimization of fitting to the tire test data curves by Magic Formula is discussed, included the digitalization of tire test data curves, designing objective functions and optimization processes,etc. Finally the parameters in Magic Formula tire model are obtained and they lay a foundation for the development of vehicle handling aftertime.  相似文献