Time filter

Source Type

Wang M.,Shandong Computer Science Center National Supercomputer Center in Jinan | Wang M.,Shandong Provincial Key Laboratory of Computer Networks | Zhang Z.,Qufu Normal University
Journal of the Franklin Institute | Year: 2015

In this paper, the problem of globally stable adaptive fuzzy tracking control is addressed for a class of uncertain nonlinear systems in the canonical form. Instead of linearly parameterized fuzzy logic system (FLS), nonlinearly parameterized FLS is used to approximate the unknown nonlinear function. By combining the new parametrization of Gaussian membership function and the signal replacement approach, a novel adaptive fuzzy controller is designed. It is shown that all signals in the closed-loop system are globally bounded and that the tracking error converges to zero asymptotically. A simulation example is included to illustrate the effectiveness of the proposed approach. © 2015 The Franklin Institute. Published by Elsevier Ltd. All rights reserved. Source

Fan M.-Q.,Southwest Jiaotong University | Liu P.-P.,Chengdu University of Technology | Wang H.-X.,Southwest Jiaotong University | Li H.-J.,Shandong Provincial Key Laboratory of Computer Networks
International Journal of Computer Mathematics | Year: 2013

In this paper, a novel semi-fragile watermarking scheme for authenticating an audio signal based on dual-tree complex wavelet transform (DT-CWT) and discrete cosine transform (DCT) is proposed. Specifically, the watermark data are efficiently inserted into the coefficients of the low-frequency sub-band of DT-CWT taking advantages of both DCT and quantization index modulation (QIM). First, the original digital audio signal is segmented and then performed with DT-CWT. Second, based on the energy compression property, the low-frequency sub-band coefficients of the DT-CWT domain are performed with DCT, and the DC component is utilized to embed one distorted watermark bit by the QIM technique. Finally, inverse DCT and DT-CWT are orderly implemented on the watermarked coefficients of each audio segment to get a watermarked audio signal. Simulation results show that the hybrid embedding domain constructed by DT-CWT and DCT is effective, and the proposed watermarking scheme is not only inaudible, but also robust against content persistent non-malicious audio signal processing operations, such as MP3 compression, noise addition, re-sampling, re-quantization, etc. Furthermore, the proposed scheme can effectively authenticate the veracity and integrity of audio content and greatly expands the applicability of the audio watermarking scheme. © 2013 Taylor & Francis. Source

Du T.,University of Jinan | Qu Z.,Shandong Computer Science Center | Qu Z.,Shandong Provincial Key Laboratory of Computer Networks | Guo Q.,University of Jinan | Qu S.,University of Jinan
International Journal of Distributed Sensor Networks | Year: 2015

Data aggregation is an important method of improving transmitting efficiency of WSNs, but existing researches have some disadvantages as follows: several periods delay will be generated when filtering messages; the reduplicated messages filtering ratio is low; complex calculations need to be executed; and extra hardware should be added to obtain high performance. To resolve these problems, this paper proposes a real time and high efficient data aggregation scheme (dynamical message list based data aggregation, DMLDA) based on clustering routing algorithm. DMLDA includes three procedures: activating nodes, clustering nodes, and filtering messages. In filtering procedure, a special data structure named dynamic list will be established in every filtering node; it is designed to store messages transmitted by filtering node, and, comparing current message with list's items, the message's redundancy can be judged without any delay. To improve the filtering efficiency, the message list can be adjusted dynamically. The three procedures of data aggregation are all introduced, and the filtering method is designed in detail in this paper. At last, a series of experiments are simulated to prove our scheme's performance, and the advantages are analyzed in theory. © 2015 Tao Du et al. Source

Li X.-F.,Chinese Academy of Sciences | Zhang X.-C.,Shandong Academy of Sciences | Zhang X.-C.,Shandong Provincial Key Laboratory of Computer Networks | Yang M.-H.,Shandong Academy of Sciences | And 2 more authors.
Dianzi Yu Xinxi Xuebao/Journal of Electronics and Information Technology | Year: 2011

To address the state explosion problem in the procedure of model checking, this paper proposes a SPIN-based modularized model checking method. The proposed method divides the original abstraction model into some modules, and verifies all the divided modules, instead of verifying the original model. In the dividing process, the semantic of original model can be completely included in the modules, and no semantic is added in the process. Consequently, the original model passes the verification of model checking if and only if all the modules pass the verification. The theoretical and experimental results show that the proposed method is valid. Source

Chen C.,Shandong Computer Science Center National Supercomputer Center in Jinan | Chen C.,Beihang University | Jia Y.,Beihang University | Shu M.,Shandong Computer Science Center National Supercomputer Center in Jinan | And 3 more authors.
IEEE Transactions on Intelligent Transportation Systems | Year: 2015

This paper presents a hierarchical controller for an autonomous vehicle to track a reference path in the presence of uncertainties in both tire-road condition and external disturbance. The hierarchical control architecture consists of three layers: high, low, and intermediate levels. The upper-layer module deals with the vehicle motion control objective, which generates the desired longitudinal/lateral forces and yaw moment. The low-level module handles the braking control for each wheel based on the wheel slip dynamics. The intermediate-level controller generates the longitudinal slip reference for the low-level brake control module and the front-wheel steering angles. To cope with the unknown and nonuniform road condition parameters appearing in the actuator models, an adaptive law is designed for each wheel, and the convergence of the adaptive parameters is guaranteed under a certain persistency-of-excitation condition. The stability of the integrated control system is analyzed by utilizing a Lyapunov function approach. Simulation results are included to illustrate the proposed control scheme. © 2000-2011 IEEE. Source

Discover hidden collaborations