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Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2007年第8期8卷 1246-1255页

作者： YAN zhi-guo wang zhi-zhong REN Xiao-mei Departmen of Biomedical Engineering Shanghai Jiao Tong University Shanghai 200030 China

This paper presents an effective and efficient combination of feature extraction and multi-class classifier for motion classification by analyzing the surface electromyografic(sEMG) signals. In contrast to the existing methods,considering the non-stationary and nonlinear characteristics of EMG signals,to get the more separable feature set,we introduce the empirical mode decomposition(EMD) to decompose the original EMG signals into several intrinsic mode functions(IMFs) and then compute the coefficients of autoregressive models of each IMF to form the feature set. Based on the least squares support vector machines(LS-SVMs) ,the multi-class classifier is designed and constructed to classify various motions. The results of contrastive experiments showed that the accuracy of motion recognition is improved with the described classification scheme. Furthermore,compared with other classifiers using different features,the excellent performance indicated the potential of the SVM techniques embedding the EMD-AR kernel in motion classification.

关键词： Electromyografic signal Empirical mode decomposition (EMD) Auto-regression model Wavelet packet transform Least squares support vector machines (LS-SVM) Neural network

Some generalized limit theorems concerning delayed sums of random sequence

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Applied Mathematics(A Journal of Chinese Universities) 2013年第1期28卷 40-48页

作者： wang zhong-zhi YANG Wei-guo SHI zhi-yan School of Mathematics & Physics AnHui University of Technology Faculty of Science Jiangsu University

For a sequence of arbitrarily dependent m-valued random variables （Xn） n∈N , the generalized strong limit theorem of the delayed average is investigated. In our proof, we improved the method proposed by Liu [6] . A... 详细信息

关键词： Limit theorem delayed average Borel-Cantelli lemma inhomogeneous Markov chain.

Multifractal analysis of surface EMG signals for assessing muscle fatigue during static contractions

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Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2007年第6期8卷 910-915页

作者： wang Gang REN Xiao-mei LI Lei wang zhi-zhong Department of Biomedical Engineering Shanghai Jiao Tong University Shanghai 200240 China

This study is aimed at assessing muscle fatigue during a static contraction using multifractal analysis and found that the surface electromyographic （SEMG） signals characterized multiffactality during a static contraction. By applying the method of direct determination ofthef（a） singularity spectrum, the area of the multifractal spectrum of the SEMG signals was computed. The results showed that the spectrum area significantly increased during muscle fatigue. Therefore the area could be used as an assessor of muscle fatigue. Compared with the median frequency （MDF）--the most popular indicator of muscle fatigue, the spectrum area presented here showed higher sensitivity during a static contraction. So the singularity spectrum area is considered to be a more effective indicator than the MDF for estimating muscle fatigue.

关键词： Muscle fatigue Surface electromyographic (SEMG) signals Multifractal Static contraction

Broadband Source Ranging in Shallow Water Using the Ω-Interference Spectrum

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Chinese Physics Letters 2010年第6期27卷 110-113页

作者： ZHAO Zhen-Dong wang Ning GAO Da-zhi wang Hao-zhong College of Information Science and Engineering Ocean University of China Qingdao 266100

The concept of the waveguide invariant is revisited and a simple relationship between the range of source and the quasi-period of the acoustic interference spectrum in the frequency domain （Ω-interference spectrum） is derived. Then a method for a broadband source ranging in shallow water using a single receiver and a broadband guide source, requiring no modeling and no knowledge about the ocean environment, is proposed. The method is validated by simulation and verified with the experimental data.

关键词： Methods Broadband Source Ranging Ω-Interference Spectrum

INDO　Studies　on　the　Electronic　Structure　of(2,4-C₇H₁₁)₂Yb（DME）

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Chemical Research in Chinese Universities 1998年第1期14卷 59-64页

作者： Feng, Jian-nan wang, zhi-zhong Zhang, So-bo Liu, Ju-zheng Jilin Univ Inst Theoret Chem Changchun 130023 Peoples R China Jilin Univ Dept Chem Changchun 130023 Peoples R China

ＩＮＤＯＳｔｕｄｉｅｓｏｎｔｈｅＥｌｅｃｔｒｏｎｉｃｓＳｔｒｕｃｔｕｒｅｏｆ（２，４－Ｃ７Ｈ１１）２Ｙｂ（ＤＭＥ）ＦＥＮＧＪｉａｎ－ｎａｎ，ＷＡＮＧＺｈｉ－ｚｈｏｎｇ，ＺＨＡＮＧＳｏ－ｂｏ，ＬＩＵＪｕ－ｚｈｅｎｇ（Ｉ... 详细信息

ＩＮＤＯＳｔｕｄｉｅｓｏｎｔｈｅＥｌｅｃｔｒｏｎｉｃｓＳｔｒｕｃｔｕｒｅｏｆ（２，４－Ｃ７Ｈ１１）２Ｙｂ（ＤＭＥ）ＦＥＮＧＪｉａｎ－ｎａｎ，ＷＡＮＧＺｈｉ－ｚｈｏｎｇ，ＺＨＡＮＧＳｏ－ｂｏ，ＬＩＵＪｕ－ｚｈｅｎｇ（ＩｎｓｔｉｔｕｔｅｏｆＴｈｅｏｒｅｔ...

关键词： INDO Studies Electronic the Structure DME C7H Yb

Interaction Effects of Gene Polymorphisms and Obesity on Nonalcoholic Fatty Liver Disease

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Biomedical and Environmental Sciences 2019年第10期32卷 793-796页

作者： SUN Xiao Ya HE zhi Qiang wang Li Qun wang zhi zhong BAI Fei Hu YOU Yan Jie Department of Epidemiology and Statistic School of Public Health and ManagementNingxia Medical UniversityYinchuan 750004NingxiaChina Department of gastroenterology at Ningxia Hui Autonomous Region People's Hospital Yinchuan 750021NingxiaChina

Nonalcoholic fatty liver disease(NAFLD)is a common chronic condition that affects adults and has a global prevalence of 25%[1],with the prevalence being 31%among the general population in China[2].A meta-analysis of studies conducted over the past few years has reported that the predicting factors for NAFLD include obesity,type 2 diabetes mellitus,lifestyle,and genetic *** risk of developing NAFLD has been reported to be 3.5-fold higher in individuals with obesity than in the general[3].

关键词： NAFLD obesity prevalence

Characterization of surface EMG signals using improved approximate entropy

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Journal of Zhejiang University-Science B(Biomedicine & Biotechnology) 2006年第10期7卷 844-848页

作者： CHEN Wei-ting wang zhi-zhong REN Xiao-mei Department of Biomedical Engineering Shanghai Jiao Tong University Shanghai 200240 China

An improved approximate entropy (ApEn) is presented and applied to characterize surface electromyography (sEMG) signals. In most previous experiments using nonlinear dynamic analysis, this certain processing was often confronted with the problem of insufficient data points and noisy circumstances, which led to unsatisfactory results. Compared with fractal dimension as well as the standard ApEn, the improved ApEn can extract information underlying sEMG signals more efficiently and accu- rately. The method introduced here can also be applied to other medium-sized and noisy physiological signals.

关键词： Surface EMG (sEMG) signal Nonlinear analysis Approximate entropy (ApEn) Fractal dimension

Geometry optimization and electronic structures of molecules H_3AXAH_3

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Chinese Journal of Chemistry 1992年第1期10卷 1-4页

作者： wang,zhi-zhong SHEN,Er-zhong Institute of Theoretical Chemistry,Jilin University,Changchun 130023 Institute of Theoretical Chemistry Jilin University Changchun 130023

The geometries of molecules H_3AXAH_3(X=O,S,Se and A=C,Si)have been optimized using STO-3G ab initio calculations and gradient method and the results are in good agreement with reported experimental *** the STO-3G optimized geometries,we have also calculated the electronic structures of these molecules using 4-31G and 6-31G basis sets to obtain the MO energies. atomic net charges and dipole *** ionization potentials calculated by 6-31G basis set are in good agreement with experimental values.

关键词： STO Geometry optimization and electronic structures of molecules H3AXAH3

Electronic structure and photoelectron spectrum Assignment of allene

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Chinese Journal of Chemistry 1993年第5期11卷 406-411页

作者： wang,zhi-zhong YANG,Ming YANG,zhong-zhi Institute of Theoretical Chemistry and State Key Laboratory of Computational Theoretical Chemistry,Jilin University,Changchun,Jilin 130023 Institute of Theoretical Chemistry and State Key Laboratory of Computational Theoretical Chemistry Jilin University Changchun Jilin 130023

In this paper a series of ab initio SCF and configuration calculations were reported for the ground state and excited states X^2E, A^2E,~2B_2 and ~2A_1 of *** ground state X^2E Jahn- Teller distorsion was discussed and a twisted angle of 50° and a torsional barriers of 0.21—0.51 eV were *** on calculated results,the experimental photoelectron spectrum of allene has been assigned.

关键词： SCF Electronic structure and photoelectron spectrum Assignment of allene Cl

Oil-gas reservoir lithofacies stochastic modeling based on one- to three-dimensional Markov chains

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Journal of Central South University 2018年第6期25卷 1399-1408页

作者： wang zhi-zhong HUANG Xiang LIANGYu-ru School of Mathematics and Statistics Central South UniversityChangsha 410012China Data Center（Beijing） Agricultural Bank of ChinaBeijing 100161China Department of Railway Locomotive and Electromechanical Equipment Shandong PolytechnicJi＇nan 250104China ~ Central South University Press and Springer-Verlag GmbH Germanypart of Springer Nature 201

Stochastic modeling techniques have been widely applied to oil-gas reservoir lithofacies. Markov chain simulation~ however~ is still under development~ mainly because of the difficulties in reasonably defining conditional probabilities for multi-dimensional Markov chains and determining transition probabilities for horizontal strike and dip directions. The aim of this work is to solve these problems. Firstly~ the calculation formulae of conditional probabilities for multi-dimensional Markov chain models are proposed under the full independence and conditional independence assumptions. It is noted that multi-dimensional Markov models based on the conditional independence assumption are reasonable because these models avoid the small-class underestimation problem. Then~ the methods for determining transition probabilities are given. The vertical transition probabilities are obtained by computing the transition frequencies from drilling data~ while the horizontal transition probabilities are estimated by using well data and the elongation ratios according to Walther＇s law. Finally~ these models are used to simulate the reservoir lithofacies distribution of Tahe oilfield in China. The results show that the conditional independence method performs better than the full independence counterpart in maintaining the true percentage composition and reproducing lithofacies spatial features.

关键词： independence assumption Markov chain reservoir lithofacies small-class underestimation transitionprobability