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浏览/检索结果: 共6条，第1-6条 帮助 限定条件 发表日期：2009    内容类型：会议论文     已选(0)清除 条数/页：5101520253035404550556065707580859095100   排序方式：请选择作者升序作者降序题名升序题名降序发表日期升序发表日期降序提交时间升序提交时间降序 System identification of tracking error and evaluation of tracking performance using BP neural network (EI CONFERENCE) 会议论文 International Symposium on Photoelectronic Detection and Imaging 2009: Advances in Infrared Imaging and Applications, June 17, 2009 - June 19, 2009, Beijing, China Zhang N.; Shen X.-H. 收藏  |  浏览/下载：13/0  |  提交时间：2013/03/25 A novel approach for evaluating the tracking performance of optoelectronic theodolite is proposed. First  an equivalent mathematic model of tracking error is established. Then  the equivalent sine signal is inputted to the equivalent model  and the outputs are sampled. The results of evaluating the tracking performance are obtained based on the statistical calculation of output produced by equivalent model. Equivalent model using the BP (Backprogration) neural network structure is identified. The training method of BP neural network adopts the LM (Levenberg-Marquardt) algorithm for the sake of speeding up training process. The BP neural network is trained and tested by using the training and testing samples gotten from the simulation model of optoelectronic theodolite tracking system under MATLAB/SIMULINK. The estimate errors of equivalent model including average error  maximum error and standard error are 2.5872e-0060  2.8 and 1.9. The results show that the equivalent model identified based on BP neural network meets the needs of evaluating the tracking performance of optoelectronic theodolite. The accurate evaluation of tracking performance is achieved. 2009 SPIE.   Orientation error analysis of alt-alt photoelectric telescope (EI CONFERENCE) 会议论文 4th International Symposium on Advanced Optical Manufacturing and Testing Technologies: Large Mirrors and Telescopes, November 19, 2008 - November 21, 2008, Chengdu, China Han X.-B.; Zhang J.-X.; Zhao J.-Y.; Zhao Y.-Z.; Wu X.-X.; Wang Z.-C. 收藏  |  浏览/下载：22/0  |  提交时间：2013/03/25 In order to ascertain the effects of main errors of alt-alt photoelectric telescope on measurement accuracy  orientation error is analyzed.For analyzing optical  mechanical and electrical errors from measured target to telescope picture  we construct 7 coordinates such as:the earth's core coordinate  alt-alt coordinate  etc.  carry through 21 times coordinate transformation  form measuring equation with 26 variables. and we utilize Monte Carlo method to calculate the orientation error  analyze the effects of errors upon pointing. The result indicates that the measuring error standard deviation of alt-alt telescope is minimum value about 10? at the zenith zone. and the deviation increases with the rotation angles of longitude and latitude axes. The model and the method not only can analyze and synthesize the main errors  but also provide a reference to the whole design. 2009 SPIE.   Prediction of melt-crystal interface shape and melt convection in a large-scale CZ-Si growth system using RANS and LES methods in global simulation 会议论文 作者:  Liu, Xin;  Liu, Lijun;  Li, Zaoyang;  Wang, Yuan;  Kakimoto, Koichi 收藏  |  浏览/下载：7/0  |  提交时间：2019/12/18 Global simulation  Growth systems  K-epsilon turbulence model  Melt convection  Melt-crystal interface shape  Solid boundaries  Standard k epsilons  Turbulent melt flows   A Two-stage Approach for Estimating Jump-diffusion Model with Application to Daily Returns of USD/CNY Exchange Rates 会议论文 2nd International Symposium on Electronic Commerce and Security, Nanchang, PEOPLES R CHINA, 2009-05-22 作者:  Yang, Ruicheng;  Zhou, Yingying 收藏  |  浏览/下载：4/0  |  提交时间：2019/12/24 USD/CNY Exchange Rates  two-stage approach  jump-diffusion model  standard Brownian motion  Poisson process   Numerical Simulation of Wind Environment around the Building with CFD Method 会议论文 International Forum on Porous Flow and Applications, Wuhan City, PEOPLES R CHINA, APR 24-26, 2009 作者:  Duan Xiang*;  He Xiang 收藏  |  浏览/下载：3/0  |  提交时间：2019/12/27 CFD method  standard K- epsilon turbulent flow model  wind environment  asymmetrical building   A dynamic description logic for UML 会议论文 Hainan Island, China, April 25, 2009 - April 26, 2009 作者:  Li, Ming;  Zang, Fengkui 收藏  |  浏览/下载：0/0  |  提交时间：2020/11/15 Artificial intelligence  Computability and decidability  Data description  Formal languages  Modeling languages  Semantics  Description logic  Dynamic actions  Dynamic description logic  Dynamic extension  Reasoning tasks  Satisfiability checking  Sound and complete  Standard model