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Chinese Journal of electronics 2014年第2期23卷 415-418页

作者： WANG Jun NING Huansheng DONG Han HONG Tao XIONG Qingxu MAO Lingfeng School of electronic and Information Engineering Beihang University institute of intelligent Structure and system Soochow University

A The resonance of the Modified dumbbellshaped defected ground structure(MD-DGS) resonator on coplanar waveguide is investigated systematically based on the phase coherence of electromagnetic *** the analysis of two presented interference modes,the resonant frequencies can be fully predicted,and the physical understanding behind these resonances is clearly *** proposed analysis is verified by the simulation and measurement results of the MD-DGS *** the electric field distribution and the Poynting vector distribution of the MD-DGS resonator at the resonant frequencies further demonstrate the validity of the theoretical analysis.

关键词： Phase coherence Resonant frequency Defected ground structure

Knowledge Representation in KDD Based on Linguistic Atoms

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Journal of Computer Science & Technology 1997年第6期12卷 481-496页

作者：李德毅 institute of China electronic system Engineering Beijing

An important issue in Knowledge Discovery in Databases is to allow the discovered knowledge to be as close as possible to natural languages to satisfy user needs with tractability on one hand, and to offer KDD systems robustness on the other hand. At this junction, this paper describes a new concept of linguistic atoms with three digital characteristics: expected value Ex, entropy En, and deviation D. The mathematical description has effectively illtegrated the fuzziness and randomness of linguistic terms in a unified way Based on this model a method of knowledge representation in KDD is developed which bridges the gap between quantitative knowledge and qualitative knowledge. Mapping between quantitatives and qualitatives becomes much easier and interchangeab1e. In order to discover genera1ized knowledge from a database, one may use virtual linguistic terms and cloud transforms for the auto-generation of concept hierarchies to attributes. Predictive data mining with the cloud model is given for implementation. This further illustrates the advantages of this linguistic model in KDD.

关键词： Qualitative representation linguistic atom compatibility cloud,concept hierarchy cloud transform

Enhancing recommender systems by incorporating social information

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Journal of Zhejiang University-Science C(Computers and electronics) 2013年第9期14卷 711-721页

作者： Li-wei HUANG Gui-sheng CHEN Yu-chao LIU De-yi LI institute of Command Information system PLA University of Science and Technology institute of electronic system Engineering

Although recommendation techniques have achieved distinct developments over the decades,the data sparseness problem of the involved user-item matrix still seriously influences the recommendation *** of the existing techniques for recommender systems cannot easily deal with users who have very few *** to combine the increasing amount of different types of social information such as user generated content and social relationships to enhance the prediction precision of the recommender systems remains a huge *** this paper,based on a factor graph model,we formalize the problem in a semi-supervised probabilistic model,which can incorporate different user information,user relationships,and user-item ratings for learning to predict the unknown *** evaluate the method in two different genres of datasets,Douban and *** indicate that our method outperforms several state-of-the-art recommendation ***,a distributed learning algorithm is developed to scale up the approach to real large datasets.

关键词： Recommender system Social information Factor graph model

Simulation design of fuze warhead system of air defense missile at very low altitude

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Journal of systems Engineering and electronics 2017年第3期28卷 572-584页

作者： Qi Zhao Guangyu Du Bin Zhang Yanbin Zhai Yuruo Shi Beijing institute of electronic system Engineering Beijing 100854China

A novel simulation method for fuze warhead system (FWS) at very low altitude flight is proposed to solve adaptability issues of the traditional one in the naval battle. Firstly, a simulation system framework is presented. Then the detailed implementation of a novel general fuze model, a novel sea echo model and a novel warhead dynamic effectiveness power field algorithm including the simulation system are presented. Finally, simulation results show good performance of the proposed method. The proposed method can simulate the echo signal when the complex fuze antennas detect target and the sea at the same time, and can truly reflect the target positions hit by the warhead fragments. The proposed method can solve the existing problems in the FWS simulation system.

关键词： fuze warhead system (FWS) simulation fuze warhead matching sea echo fragment trajectory drifting

Nonlinear flutter wind tunnel test and numerical analysis of folding fins with freeplay nonlinearities

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Chinese Journal of Aeronautics 2016年第1期29卷 144-159页

作者： Yang Ning Wang Nan Zhang Xin Liu Wei Beijing institute of electronic system Engineering Beijing 100854China

The flutter characteristics of folding control fins with freeplay are investigated by numer- ical simulation and flutter wind tunnel tests. Based on the characteristics of the structures, fins with different freeplay angles are designed. For a 0° angle of attack, wind tunnel tests of these fins are conducted, and vibration is observed by accelerometers and a high-speed camera. By the expansion of the connected relationships, the governing equations of fit for the nonlinear aeroelastic analysis are established by the free-interface component mode synthesis method. Based on the results of the wind tunnel tests, the flutter characteristics of fins with different freeplay angles are analyzed. The results show that the vibration divergent speed is increased, and the divergent speed is higher than the flutter speed of the nominal linear system. The vibration divergent speed is increased along with an increase in the freeplay angle. The developed free-interface component mode synthesis method could be used to establish governing equations and to analyze the characteristics of nonlinear aeroe- lastic systems. The results of the numerical simulations and the wind tunnel tests indicate the same trends and critical velocities.

关键词： Folding wing Freeplay nonlinearity Nonlinear aeroelasticity Free-interfa componentmode synthesis method Wind tunnel test

Radar Sea Clutter Suppression and Target Indication with a Spatial Tracking Filter

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Tsinghua Science and Technology 2010年第2期15卷 228-234页

作者：刘婧瑶孟华东张颢王希勤 intelligent Transportation Information system Laboratory Department of Electronic Engineering Tsinghua University

It is an important issue to study sea clutter suppression because it could interfere with the detection of targets above the sea surface severely. Spatial spectrum analyses show that the majority of sea clutter has low-frequency characteristics, compared to the high-frequency characteristics of the targets. This paper proposes a frequency-based spatial tracking filter to suppress sea clutter to facilitate targets identification. Experimental results show that the signal-to-clutter ratio can increase by more than 10 dB after filtering and the algorithm is feasible for practical use. In addition, the filtering equation can be optimized to maximize the signal-to-clutter ratio improvement. The equation parameters can also be adjusted to give a proper cut-off frequency for different targets and clutter.

关键词： spatial spectrum spatial tracking filter sea clutter suppression target indication

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A Fuzzy Proof Theory

Journal of Computer Science & Technology 1990年第1期5卷 92-96页

作者：刘东波李德毅 The institute of China electronic system Engineering Company

Based on the first order predicate logic, in this paper, we present a new approach to generalizing the syn- tax of ordinary Horn clause rules to establish a fuzzy proof theory. First of all, each Horn clause rule is associ- ated with a numerical implication strength f. Therefore we obtain f-Horn clause rules. Secondly, Herbrand in- terpretations can be generalized to fuzzy subsets of the Herbrand base in the sense of Zadeh. As a result the proof theory for Horn clause rules can be developed in much the same way for f-Horm clause rules.

关键词： node A Fuzzy Proof Theory tree

Modeling and analysis of car-following behavior considering backward-looking effect

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Chinese Physics B 2021年第3期30卷 326-334页

作者： Dongfang Ma Yueyi Han Fengzhong Qu Sheng Jin Ocean College Institute of Marine Information Science and TechnologyZhejiang UniversityHangzhou 310058China College of Civil Engineering and Architecture Institute of Intelligent Transportation SystemZhejiang UniversityHangzhou 310058China

The car-following behavior can be influenced by its driver’s backward-looking *** in traffic congestion,if vehicles adjust the headway by considering backward-looking effect,the stability of traffic flow can be enhanced.A model of car-following behavior considering backward-looking effect was built using visual information as a *** critical stability conditions were derived by linear and nonlinear stability *** results of parameter sensitivity analysis indicate that the stability of traffic flow was enhanced by considering the backward-looking *** spatiotemporal evolution of traffic flow of different truck ratios and varying degrees of backward-looking effect was determined by numerical *** study lays a foundation for exploring the complex feature of car-following behavior and making the intelligent network vehicles control rules more consistent with human driver habits.

关键词： traffic flow car-following model visual angle backward-looking effect

A Lightweight Deep Learning-Based Algorithm for Array Imperfection Correction and DOA Estimation

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Journal of Communications and Information Networks 2022年第3期7卷 296-308页

作者： Wenwei Fang Zhihui Cao Dingke Yu Xin Wang Zixian Ma Bing Lan Chunyi Song Zhiwei Xu institute of marine electronic and intelligent system Ocean CollegeZhejiang UniversityZhoushan 316021China Engineering Research Center of Oceanic Sensing Technology and Equipment Ministry of EducationZhoushan 316021China Donghai Lab Zhoushan 316021China

Array imperfections will lead to serious performance degradation of the deep neural network(DNN)based direction of arrival(DOA)estimation in the low earth orbit(LEO)satellite communication by producing a mismatch between inference data and training *** this paper,we propose a lightweight deep learning-based algorithm for array imperfection correction and DOA *** preprocessing the covariance matrix of the array antenna outputs to the image,the array imperfection correction and DOA estimation problems are correspondingly converted into the image-to-image transformation task and image recognition ***,for the deployment of real-time DNN-based DOA estimation on the resource-constrained edge system,generative adversarial network(GAN)model compression is applied to obtain a lightweight student generator of Pix2Pix for array imperfection *** Mobilenet-V2 is then used to extract the DOA information from the covariance matrix *** results demonstrate that the DOA estimation performance is significantly improved through the array imperfection *** proposed algorithm also better satisfies the real-time demand with decreased inference time on the resource-constrained edge system.

关键词： deep learning array imperfection DOA estimation model compression edge-AI

Histogram of the Oriented Gradient for Face Recognition

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Tsinghua Science and Technology 2011年第2期16卷 216-224页

作者：舒畅丁晓青方驰 State Key Laboratory of intelligent Technology and system Department of Electronic EngineeringTsinghua University

The histogram of oriented gradient has been successfully applied in many research fields with excellent performance especially in pedestrian detection. However, the method has rarely been applied to face recognition. Aimed to develop a fast and efficient new feature for face recognition, the original HOG and its variations were applied to evaluate the effects of different factors. An information theory-based criterion was also developed to evaluate the potential classification power of different features. Comparative experiments show that even with a relatively simple feature descriptor, the proposed HOG feature achieves almost the same recognition rate with much lower computational time than the widely used Gabor feature on the FRGC and CAS-PEAL databases.

关键词： face recognition feature histogram of oriented gradient