检索结果-南通市图书馆

Earthquake Engineering and Engineering Vibration 2003年第2期2卷 225-236页

作者：杜修力曾迪 Beijing University of technology Beijing 100022China Professor China Institute of Water Resources and Hydropower Research Beijing 100044China Assistant Engineer

Evolutionary computation based on the idea of biologic evolution is one type of global optimization algorithm that uses self-adaptation,self-organization and random searching to solve optimization *** evolutionary-simplex algorithm is introduced in this *** contains floating encoding which combines the evolutionary computation and the simplex algorithm to overcome the problems encountered in the genetic algorithm and evolutionary strategy methods. Numerical experiments are performed using seven typical functions to verify the *** inverse analysis method to identify structural physical parameters based on incomplete dynamic responses obtained from the analysis in the time domain is presented by using the evolutionary-simplex *** modal evolutionary-simplex algorithm converted from the time domain to the modal domain is proposed to improve the inverse *** calculations for a 50-DOF system show that when compared with other methods,the evolutionary-simplex algorithm offers advantages of high precision, efficient searching ability,strong ability to resist noise,independence of initial value,and good adaptation to incomplete information conditions.

关键词： modal paralneter physical parameter inverse analysis evolutionary-simplex algorithm

Narrowband imaging method for spatial precession cone-shaped targets

在线全文

学校读者我要写书评

暂无评论

Science China(Technological Sciences) 2010年第4期53卷 942-949页

作者： DING XiaoFeng1,FAN MeiMei1,WEI XiZhang1,LI Xiang1 & Xiao HuaiTie2 1 Institute of Space Electronics information technology,National University of Defense technology,Changsha 410073,China 2 School of Electronic Science and Engineering,National University of Defense technology,Changsha 410073,China Institute of Space Electronics information technology National University of Defense Technology Changsha China School of Electronic Science and Engineering National University of Defense Technology Changsha China

The imaging method of the mid-course missile is the key technique of the missile defense *** of the special precession character of the ballistic missile warhead,the inverse synthetic aperture radar method cannot realize phase compensation with the constant phase offset function,which leads to blurring of the *** this paper,we propose a new narrowband radar imaging method for the precession cone-shaped *** method acquires the Doppler modulation of the precession target's scattering centers with high resolution time-frequency analysis method and extracts the Doppler parameter from the result of the time-frequency analysis with the general Radon transform,then reconstructs the scattering centers positions in the parameter *** experiment results with the anechoic chamber data of the representative cone-shaped object showed the effectiveness of the method.

关键词： narrowband radar imaging time-frequency analysis general Radon transform

Focusing enhanced broadband metalens via height optimization

在线全文

学校读者我要写书评

暂无评论

Optoelectronics Letters 2022年第2期18卷 72-76页

作者： WANG Junjie CHEN Deli WANG Zhan XUE Qi SUN Xiaohong Henan Key Laboratory of Laser and Opto-electric information technology School of Information EngineeringZhengzhou UniversityZhengzhou 450001China

Metalenses are two-dimensional planar metamaterial lenses, which have the advantages of high efficiency and easy integration. Based on the method of spatial multiplexing, a metalens with a wide working waveband is designed by arranging Ti O2 nanopillars under the resonance phase regulation. In addition, choosing an assistant metalens with optimized heights is effective to enhance metalens’ s focusing, which is also illustrated in this paper. The metalens, designed with numerical aperture(NA) of 0.72 and center working wavelength of 600 nm, achieves the working waveband of 550-660 nm, the focus point’s size of below 420 nm, and the focusing efficiency of more than 30%.

关键词： Focus ens multiplexing

Drive Control of Spiral Wave and Turbulence by a Target Wave in CGLE

在线全文

学校读者我要写书评

暂无评论

Communications in Theoretical Physics 2013年第10期60卷 439-444页

作者：向秀桥施保昌何耀耀 Faculty of information Engineering China University of Geosciences School of Mathematics and Statistics Huazhong University of Science and Technology School of Management Hefei University of Technology

Suppression of spiral wave and turbulence in the complex Cinzburg-Landau equation （CCLE） plays a prominent role in nonlinear science and complex dynamical system. In this paper, the nonlinear behavior of the proposed drive-response system, which consists of two coupled OGLEs, is investigated and controlled by a state error feedback controller with the lattice Boltzmann method. First, spiral wave appropriate parameters of the response system under the no-flux and turbulence are, respectively, generated by selecting boundary and perpendicular gradient initial conditions. Then, based on the random initial condition, the target wave yielded by introducing spatially localized inhomogeneity into the drive system is applied on the above response system. The numerical simulation results show that the spiral wave and turbulence existing in the response system could be successfully eliminated by the target wave in the drive system during a short evolution time. Furthermore, it turns out that the transient time for the drive course is related to the control intensity imposed on the whole media.

关键词： lattice Boltzmann method nonlinear system complex Ginzburg-Landau equation spiral wave drive control

The Instructional Design of Chinese Text Classification based on SVM 25th

在线全文

学校读者我要写书评

暂无评论

The Instructional Design of Chinese Text Classification base...

The Design of Digit Recognition Teaching Experiment Based on BP Neural Network

第25届中国控制与决策会议

作者： Sichao Wei Jianyi Guo Zhengtao Yu Peng Chen Yantuan Xian School of information Engineering and Automation Kunming University of Science and Technology Intelligent information Processing Key Laboratory Kunming University of Science and Technology

ISBN: (纸本)9781467355339

In order to resolve the comprehension difficulties of theory and implementation about Chinese text classification in " The principle and application of pattern recognition" curriculum for graduate students, this paper introduces the experiment of Chinese text classification into teaching practice. According to the text classification characteristics, we design the experiment scheme about Chinese text classification based on SVM, using word frequency statistics to extract feature and SVM classification algorithm, using vector space model to construct the feature space of text classification. So that readers can deeply understand and master the theoretical knowledge through the open the link, then expand on this basis

关键词： feature selection support vector machine algorithm text classification teaching experiment

来源： cnki会议评论

在线全文

cnki会议

学校读者我要写书评

暂无评论

The Design of Digit Recognition Teaching Experiment Based on...

Optimization of n/i and i/p buffer layers in n-i-p hydrogenated microcrystalline silicon solar cells

第25届中国控制与决策会议

作者： Haitao Yu Jianyi Guo Zhengtao Yu Yantuan Xian Peng Chen School of information Engineering and Automation Kunming University of Science and Technology Intelligent information Processing Key Laboratory Kunming University of Science and Technology

ISBN: (纸本)9781467355339

The teaching of pattern recognition course in postgraduates’ study is too theoretical to learn, and lack of teaching experiments. To solve these problems, this paper researches and explores on how to design digit recognition experiment in this *** propose an digit recognition teaching plan based on BP neural network. Firstly, we summarize the development and application of digit recognition, as well as the existing problems during the teaching activities at present;then, we use the case teaching method to explain the experimental procedures,and use the method of BP neural network to recognise digit, including the principle of digit recognition, the principle of image preprocessing and the design of neural network, and so on. With the aims of optimizing the original teaching form, stimulating students’ study interests, training their abilities of practice and scientific research , we introduce the design of experiment. Finally, help students to solve practical problems..

关键词： The practice of pattern recognition course BP neural network Digit recognition

来源： cnki会议评论

在线全文

cnki会议

学校读者我要写书评

暂无评论

Journal of Semiconductors 2009年第3期30卷 67-71页

作者：袁育杰侯国付张建军薛俊明曹丽冉赵颖耿新华 Institute of Photoelectronics Nankai University Tianjin Key Laboratory of Photoelectronic Thin Film Devices and technology Key Laboratory of Optoelectronic information Science and technology Chinese Ministry of Education

Hydrogenated microcrystalline silicon （μc-Si：H） intrinsic films and solar cells with n-i-p configuration were prepared by plasma enhanced chemical vapor deposition （PECVD）. The influence of n/i and i/p buffer layers on the μc-Si：H cell performance was studied in detail. The experimental results demonstrated that the efficiency is much improved when there is a higher crystallinity at n/i interface and an optimized a-Si：H buffer layer at i/p interface. By combining the above methods, the performance of μc-Si：H single-junction and a-Si：H/μc-Si：H tandem solar cells has been significantly improved.

关键词： microcrystalline silicon interface buffer layer n-i-p solar cells

User Modeling for Personalized Recommender Systems

在线全文

学校读者我要写书评

暂无评论

Tsinghua Science and technology 2005年第Z1期10卷 772-777页

作者： LIU Lu WU Lihua School of Economics and Management Beihang University Beijing 100083 China Department of Information Systems Beijing Information Science and Technology UniversityBeijing 100101 China

This paper models a user's interest and value related characteristics based on the extension by using neural networks and econometric techniques to the concept of user model in recommender systems. A two-dimensional taxonomy of user model was proposed in terms of the content and persistence of user characteristics. A user interest model and a customer lifetime value model were developed for the proposed taxonomy framework, to capture the time-dependent evolving nature of user's interests and his/her long-term profitability. The proposed models were empirically validated by using real customer data from a bee product company in health care industry. The experimental results show that these models provide effective assistant tools for the company to target its most valuable customers and implement one-to-one personalized services.

关键词： user interest model customer lifetime value (CLV) recommender systems customer relationship management (CRM) e-commerce

A Novel Fast Terminal Sliding Mode Control Method Based on Immersion and Invariance for course Control of USV

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

A Novel Fast Terminal Sliding Mode Control Method Based on I...

Secure Localization Based Authentication (SLA) Strategy for Data Integrity in WNS

第36届中国控制会议

作者： XUE Wentao ZHANG Chen LI Jianzhen WANG Yulong School of Electronics and information Jiangsu University of Science and Technology

ISBN: (纸本)9781538629185

The course control of an unmanned surface vehicle（USV） with water-jet-propelled is addressed using a novel fast terminal sliding mode control approach based on system immersion and manifold invariant（FTSMC-I＆I）.The control scheme can ensure all error signals globally exponentially converge to origin in finite-time by the novel fast terminal sliding mode *** addition,I＆I method is applied to design an adaptive disturbance estimator in order to improve estimation accuracy and convergence speed with respect to parametric uncertainties and disturbances that are encountered in sailing ***,an additional compensation item is introduced into the adaptive law to keep the estimation error manifold invariant and *** a result,the estimation error of disturbances tends to zero and its dynamic process can be *** is shown that the proposed method can guarantee the asymptotical stability and the finite time convergence of the system from Lyapunov stability *** with the backstepping adaptive sliding mode control,the proposed control method can achieve higher precision and better robustness in the presence of practical input limits.

关键词： Unmanned surface vehicle Terminal sliding mode Immersion and invariant theory Adaptive law

来源： cnki会议评论

在线全文

cnki会议

学校读者我要写书评

暂无评论

Computers, Materials & Continua 2021年第6期67卷 4005-4018页

作者： V.Manikandan M.Sivaram Amin Salih Mohammed V.Porkodi K.Shankar assistant Professor Research Research CenterLebanese French UniversityErbil44001Iraq Vice President Lebanese French UniversityErbil44001Iraq Department of information technology College of Engineering and Computer ScienceLebanese French UniversityErbil44001Iraq Department of Computer Applications Alagappa UniversityKaraikudi630003India

Wireless Sensor Networks(WSN)has been extensively utilized as a communication model in Internet of Things(IoT).As well,to offer service,numerous IoT based applications need effective transmission over unstable *** ensure reliability,prevailing investigations exploit multiple candidate forwarders over geographic opportunistic routing in ***,these models are affected by crucial denial of service(DoS)attacks,where huge amount of invalid data are delivered intentionally to the receivers to disturb the functionality of ***,secure localization based authentication(SLA)is presented to fight against DoS attack,and to fulfil the need of reliability and *** examining state information,SLA projects a trust model to enhance efficacy of data ***,of the prevailing opportunistic protocols,SLA guarantees data integrity by modelling a trust based authentication,providing protection against DoS attackers and diminishing computational ***,this model acts as a verification strategy to accelerate?attackers and to handle *** strategy helps SLA in eliminating duplicate transmission and by continuous verification that results from conventional opportunistic *** is performed in a MATLAB environment that offers authentic and reliable delivery by consuming approximately 50%of the cost in contrast to other *** anticipated model shows better trade off in comparison to the prevailing ones.

关键词： Wireless sensor networks opportunistic routing secure localization based authentication denial of service computational cost