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Leshan, China

Lai J.,Leshan Normal University
Applied Mechanics and Materials | Year: 2014

Sample entropy can reflect the change of level of new information in signal sequence as well as the size of the new information. Based on the sample entropy as the features of speech classification, the paper firstly extract the sample entropy of mixed signal, mean and variance to calculate each signal sample entropy, finally uses the K mean clustering to recognize. The simulation results show that: the recognition rate can be increased to 89.2% based on sample entropy. © (2014) Trans Tech Publications, Switzerland. Source

Long S.,Leshan Normal University | Xu D.,University of Sichuan
Fuzzy Sets and Systems | Year: 2014

In this paper, we investigate the global exponential p-stability of stochastic non-autonomous Takagi-Sugeno fuzzy cellular neural networks with time-varying delays and impulses. By using the property of M-matrix, we establish a new differential inequality and a new L-operator inequality to be effective for non-autonomous Takagi-Sugeno fuzzy systems. Based on the inequalities obtained above, sufficient conditions ensuring the global exponential p-stability of the considered system are obtained. In addition, we derive sufficient conditions ensuring the global exponential stability of the corresponding autonomous systems. Our results improve some early results in the literature. One example is given to illustrate the effectiveness of our proposal. © 2013 Elsevier B.V. Source

Jing S.-Y.,Leshan Normal University
Soft Computing | Year: 2014

Rough set theory has been proven to be an effective tool to feature subset selection. Current research usually employ hill-climbing as search strategy to select feature subset. However, they are inadequate to find the optimal feature subset since no heuristic can guarantee optimality. Due to this, many researchers study stochastic methods. Since previous works of combination of genetic algorithm and rough set theory do not show competitive performance compared with some other stochastic methods, we propose a hybrid genetic algorithm for feature subset selection in this paper, called HGARSTAR. Different from previous works, HGARSTAR embeds a novel local search operation based on rough set theory to fine-tune the search. This aims to enhance GA's intensification ability. Moreover, all candidates (i.e. feature subsets) generated in evolutionary process are enforced to include core features to accelerate convergence. To verify the proposed algorithm, experiments are performed on some standard UCI datasets. Experimental results demonstrate the efficiency of our algorithm. © 2013 Springer-Verlag Berlin Heidelberg. Source

This paper discusses properties and existence conditions of minimal solutions to sup-inf fuzzy relation equations over complete Brouwerian lattices. The relationship between minimal solutions to a system of fuzzy relation equations and minimal solutions to a fuzzy relation equation in the system is illustrated by two examples. Necessary and sufficient conditions for the existence of the least solution and minimal solutions to a system of fuzzy relation equations are given. © 2012 Elsevier Inc. All rights reserved. Source

Wan H.,South China Agricultural University | Hu J.-P.,Leshan Normal University | Tian X.-H.,South China Agricultural University | Chang S.,South China Agricultural University
Physical Chemistry Chemical Physics | Year: 2013

The interaction between human complement receptor type 2 (CR2) and antigen-bound C3d can bridge the innate and adaptive immune systems. The recently determined structure of the CR2(SCR1-2):C3d complex has revealed the expected binding interface of CR2-C3d. In this article, wild type (WT) and three mutants of the new structure are studied by molecular dynamics (MD) simulations. The differently decreased structural stabilities of the mutants relative to WT are shown to be consistent with the experimental data, which can be explained by the different hydrogen bond patterns at the interfaces. It is also found that two clusters of residues (D36/E37/E39 and E160/D163/E166) in the acidic pocket of C3d are important for CR2-C3d interactions, which is in good agreement with previous mutagenesis study. In addition, functional dynamics and the conformational change of CR2 are explored by using domain cross-correlation map (DCCM), principal component analysis (PCA), and free energy landscape (FEL) methods. The conformational change mainly corresponds to the opening of a V-shaped structure of CR2, which is consistent with the previously reported high interdomain flexibility of CR2. We further suppose that the opening of a V-shaped structure of CR2 may favor the binding stability of CR2(SCR1-2):C3d. This study would provide some new insights into the understanding of the CR2-C3d interaction mechanism. © the Owner Societies 2013. Source

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