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Guo G.,Luoyang Normal University | Niu W.-S.,China Aeronautics Computing Technique Research Institute
Beijing Youdian Daxue Xuebao/Journal of Beijing University of Posts and Telecommunications | Year: 2011

Based on improved Lyapunov function, a new method is proposed to analyze the problem of decentralized static output feedback control for a class of nonlinear interconnected systems composed with a number of Takagi-Sugeno fuzzy bilinear subsystems with interconnections. By constructing a new Lyapunov function, some sufficient stabilization conditions are derived for the whole close-loop fuzzy interconnected systems. The stabilization conditions got by loosing the restricted conditions in the proving have less conservativeness than the existing methods. The corresponding decentralized fuzzy controller design is converted into a convex optimization problem with linear matrix inequality constraints. Analysis and simulation show that the proposed wethod has a better stabilization property.

Guo G.,Xidian University | Guo G.,Luoyang Normal University | Zhao B.,Luoyang Normal University | Niu W.,China Aeronautics Computing Technique Research Institute | Zhu M.,Xian Communication Institute
Huazhong Keji Daxue Xuebao (Ziran Kexue Ban)/Journal of Huazhong University of Science and Technology (Natural Science Edition) | Year: 2010

A new method for the delay-dependent stability analysis for continuoustime Takagi-Sugeno(T-S) fuzzy systems with a time-varying delay is suggested, which is less conservative than other existing ones. Based on a fuzzy Lyapunov-Krasovskii functional(FLKF), a delay-dependent stability criterion was derived for the fuzzy systems. In the derivation process, somefree-weighting matrices were introduced to express the relationships among theterms of the system equations, and among the terms in the Leibniz-Newton formula, which may avoid the conservation produced by some bounding inequalities for cross products between two vectors and model transformation. Finally, a simulation example shows that the approach is effective.

Niu W.,China Aeronautics Computing Technique Research Institute
Applied Mechanics and Materials | Year: 2014

As failure of rotator in rotating machinery has a certain concealment, fault diagnosis for rotator in rotating machinery based on support vector machine with particle swarm optimization algorithm is presented in the paper. And particle swarm optimization algorithm is applied to select the suitable parameters of support vector machine. In the study, we employ three PSO-SVM classifiers to recognize the four states of rotator in rotating machinery including normal state, rotor imbalance, rotor winding and rotor misalignment. More than 70 cases are used to testify the effectiveness of the PSO and SVM model compared with other classification models. The experimental results show that diagnostic precision for rotating machinery of PSO and SVM than that of SVM and BPNN. © (2014) Trans Tech Publications, Switzerland.

Li X.,Northwestern Polytechnical University | Li Z.,Northwestern Polytechnical University | Wang P.,China Aeronautics Computing Technique Research Institute | Chen Q.,Northwestern Polytechnical University | And 2 more authors.
Lecture Notes in Computer Science (including subseries Lecture Notes in Artificial Intelligence and Lecture Notes in Bioinformatics) | Year: 2012

Keyword search has attracted a great deal of attention for retrieving XML data because it is a user-friendly mechanism. In this paper, we study the problem of effective keyword search over XML documents. The paper SLCA proposed that keyword search returns the set of smallest trees, where a tree is designated as smallest if it contains no sub-tree that also contains all keywords. The paper SLCA also provided detail description of the Indexed Lookup Eager algorithm (IL) to calculate SLCA. We analyzed and experimental studied the IL algorithm of SLCA deeply, find that there are 3 bugs which should not be disregarded. This paper investigates the problems to correct the existent 3 bugs of the algorithm IL, and proposes an optimize method called XIO-SLCA to improve keyword search quality. We have conducted an extensive experimental study and the experimental results show that our proposed approach XIO-SLCA achieves both higher recall and precise when compared with the existing proposal SLCA. © 2012 Springer-Verlag.

Wang R.,China Aeronautics Computing Technique Research Institute
Journal of Applied Optics | Year: 2013

A design method based on the interface module of airborne flight control computers, which could realize digital control, real-time acquisition, monitoring and processing of various control signals (including discrete magnitude, analog quantity and serial data), was introduced. Focusing on the engineering application, the design idea and implementation methodology of the module were elaborated, as well as the self-tesing, with the illustration of principle block diagrams and testing process. In the application of a certain air freighter, the module performed the functions of the input and output of 32 interfaces discrete magnitude, the input and output of 16 interfaces analog quantity, the transceiving of 6 interfaces ARINC 429 serial data, and the transceiving of 4 interfaces ARINC 232 serial data, with the coverage of self-testing reaching 100%. The flexibility of the form and the number of the module interface enables the adjustment in accordance with the actual application; therefore the module is featured with evident typicality and generality, which can be used in various types of airborne flight control systems.

Zhang X.-M.,China Aeronautics Computing Technique Research Institute | Zhang Y.-D.,China Aeronautics Computing Technique Research Institute
Proceedings - Symposia and Workshops on Ubiquitous, Autonomic and Trusted Computing in Conjunction with the UIC 2010 and ATC 2010 Conferences, UIC-ATC 2010 | Year: 2010

In This paper, the networked control systems (NCSs) is modeled as a time-delay system. In terms of the given model. Two new asymptotic stability criterions for the linear time-invariant networked control systems are derived from the inequality of matrix norm and Lyapunov stability theory and a detail linear matrix inequality (LMI) algorithm is also presented to determine the bound of the network induce delay time. Two examples and the comparison with the corresponding papers are given to show the effectiveness of our method. © 2010 IEEE.

Wang H.,China Aeronautics Computing Technique Research Institute | Zhou H.,China Aeronautics Computing Technique Research Institute
Proceedings - 2011 IEEE International Conference on Computer Science and Automation Engineering, CSAE 2011 | Year: 2011

The safety analysis process of a kind of signal indicating embedded software is shown in this paper. A quantitative method is presented to model and evaluate software safety. The basic theory frame of Finite State Machine (FSM), Markovian theory and definition of gray entropy are presented. FSM safety model of the embedded software is built. 1-step transition probability matrixes are constructed referencing transition probability matrix concept of Markovian theory. After that, the safety of the software and the whole embedded system are discussed in detail. The analysis indicates that improving safety of the software and system is a complicated work. Hardware, algorithms and training of the operators etc. are the aspects that need to be carefully regarded. It also shows the way to accurately measure the safety of the software. The analyzing results of the software are extended to a general situation. The safety of software is predicted by using 1-step transition probability matrixes. Finally, numerical calculation is applied to validate the above analysis. © 2011 IEEE.

Dong X.-W.,Xidian University | Ma J.-F.,Xidian University | Niu W.-S.,China Aeronautics Computing Technique Research Institute | Mao L.-Q.,Xidian University | Xie H.,Xidian University
Ruan Jian Xue Bao/Journal of Software | Year: 2011

Based on the characteristics of ad hoc security routing protocols (SRPs), the advantages and disadvantages of the strand space theory are analyzed. An analysis model for protocol attacks, which leads to a nonexistent route that is accepted by the protocol, is designed on the basis of the strand space model. Finally, this paper demonstrates the usefulness of this model in the case of a security ad hoc routing protocol: Extended SRP. © Copyright 2011, Institute of Software, the Chinese Academy of Sciences.

Dong X.-W.,Xidian University | Niu W.-S.,China Aeronautics Computing Technique Research Institute | Ma J.-F.,Xidian University | Xie H.,Xidian University | Mao L.-Q.,Xidian University
Tongxin Xuebao/Journal on Communications | Year: 2011

In order to make the strand space model satisfy the special needs of anonymity analysis, based on equivalent bundles and view of observer, two kinds of sender anonymities as well as recipient anonymities were defined; relation anonymity were defined in two ways: emphasis on sender anonymity or recipient anonymity. Thus, an anonymity formalization framework based on strand space model was extended and completed. In addition, the difference among anonymity degrees of these anonymities were qualitatively researched and the anonymity of a zone-based k-anonymity routing protocol was analyzed to verify the correctness and efficiency.

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