Time filter

Source Type

Wu D.Z.,The Key Laboratory of Embedded System and Service Computing | Fang Y.,The Key Laboratory of Embedded System and Service Computing | Ma Q.S.,Shanghai Railway Telecommunication Equipment Ltd
Applied Mechanics and Materials | Year: 2014

This paper proposes a method of the fault detection and diagnosis for the railway circuit of ZPW-2000 system based on the main track voltage curve. Exact curve matching fault detection method and SVM-based fault diagnosis method are adopted. Based on envelope algorithm, exact curve matching method is used to match the detected current curve with the reference curve so as to predict whether the curve would have fault or not. Then, the SVM-based fault diagnosis method is used to make sure that the fault classification could be diagnosed intelligently. The experiment results show that the proposed method can accurately identify the track circuit fault state, and the accuracy rate in the diagnosis of the fault location is above 99%, which verify the effectiveness of the method in the fault detection and diagnosis. Introduction. © (2014) Trans Tech Publications, Switzerland.


Mo X.M.,The Key Laboratory of Embedded System and Service Computing | Fang Y.,The Key Laboratory of Embedded System and Service Computing | Yang Y.G.,Shanghai Railway Telecommunication Equipment Ltd Co.
Applied Mechanics and Materials | Year: 2013

This paper proposes a method of the fault detection and diagnosis for the railway turnout based on the current curve of switch machine. Exact curve matching fault detection method and SVM-based fault diagnosis method are adopted in the paper. Based on envelope and morpheme match algorithm, exact curve matching method is used to match the detected current curve with the reference curve so as to predict whether the curve would have fault or not. Moreover, the SVM-based fault diagnosis method is used to make sure that the fault conditions could be diagnosed intelligently. Finally, the experimental results show that the proposed method can accurately identify the turnout fault status in the conversion process, and the accuracy rate in the diagnosis of the fault location is above 98%, which verify the effectiveness of the method in the fault detection and diagnosis. © (2013) Trans Tech Publications, Switzerland.


Zhao C.,The Key Laboratory of Embedded System and Service Computing | Zhao C.,Tongji University | Miao D.,The Key Laboratory of Embedded System and Service Computing | Miao D.,Tongji University | And 5 more authors.
Neurocomputing | Year: 2013

This paper presents a novel color face recognition method called two-dimensional color uncorrelated discriminant analysis (2DCUDA), which can extract two-dimensional color uncorrelated features and simultaneously retain the face spatial structure information. The 2DCUDA method seeks to explore color uncorrelated discriminant properties of the color face images and eliminate the correlations between color-based features. The novelties of this paper are twofold. First, this paper develops a new color-based feature for face recognition, which can provide substantial mutual complementation information and improve the recognition performance. Second, theoretical analysis guarantees the uncorrelated property of the obtained color-based features. Comparative experiments on AR and FRGC-2 color face databases have been conducted to investigate the effectiveness of the proposed algorithm. Experimental results show that the proposed algorithm performs better than other color face recognition methods and the two-dimensional color uncorrelated discriminant features are more effective for low-resolution image compared with conventional gray-based features. Finally, we explain why the proposed algorithm can improve the recognition performance compared with other color face recognition methods. © 2013 Elsevier B.V.


Zhao C.,Tongji University | Zhao C.,The Key Laboratory of Embedded System and Service Computing | Lai Z.,Harbin Institute of Technology | Miao D.,Tongji University | And 5 more authors.
Neural Computing and Applications | Year: 2014

This paper develops a supervised discriminant technique, called graph embedding discriminant analysis (GEDA), for dimensionality reduction of high-dimensional data in small sample size problems. GEDA can be seen as a linear approximation of a multimanifold-based learning framework in which nonlocal property is taken into account besides the marginal property and local property. GEDA seeks to find a set of perfect projections that not only can impact the samples of intraclass and maximize the margin of interclass, but also can maximize the nonlocal scatter at the same time. This characteristic makes GEDA more intuitive and more powerful than linear discriminant analysis (LDA) and marginal fisher analysis (MFA). The proposed method is applied to face recognition and is examined on the Yale, ORL and AR face image databases. The experimental results show that GEDA consistently outperforms LDA and MFA when the training sample size per class is small. © 2013 Springer-Verlag London.


Liu X.,Tongji University | Liu X.,The Key Laboratory of Embedded System and Service Computing | Liu Y.,Tongji University | Liu Y.,The Key Laboratory of Embedded System and Service Computing | Zhou L.,Tongji University
Neurocomputing | Year: 2015

In this paper, the quasi-synchronization of nonlinear coupled networks in the presence of parameter mismatches with time delay via aperiodically intermittent pinning control is investigated. There are two main differences of this paper with previous works: one is that the intermittent pinning control is aperiodic while that in previous works is periodic; the other is that the model is generalized from master-slave coupled systems of only two nodes to general nonlinear coupled networks. By using the aperiodically intermittent pinning control technique, a simple controller to pin the coupled networks to achieve quasi-synchronization is designed. Some sufficient criteria are obtained to guarantee global quasi-synchronization. Moreover, an adaptive algorithm for the control strength is also proposed to realize the quasi-synchronization. Finally, numerical simulations are given to show the validity of our theoretical results. © 2015 Elsevier B.V.


Liu X.,Tongji University | Liu X.,The Key Laboratory of Embedded System and Service Computing | Li P.,Tongji University | Li P.,The Key Laboratory of Embedded System and Service Computing | Chen T.,Fudan University
Neurocomputing | Year: 2015

In this paper, we investigate the cluster synchronization for linearly coupled networks with constant time delay by pinning periodically intermittent controllers. The network topology can be directed. The time delay is assumed to be less than the control width. At first, we give some criteria for cluster synchronization under constant pinning control strategy. Furthermore, by applying the adaptive approach, we design a centralized adaptive algorithm on the intermittent control gain, and also prove its validity rigorously. Finally, numerical simulations are given to demonstrate the correctness of obtained theoretical results. © 2015 Elsevier B.V..


Liu X.,Tongji University | Liu X.,The Key Laboratory of Embedded System and Service Computing | Xu Y.,Tongji University | Xu Y.,The Key Laboratory of Embedded System and Service Computing
Neurocomputing | Year: 2015

In this paper, we investigate the cluster synchronization problem of complex networks via pinning control. Nodes in the same cluster are governed by the same dynamical function, while the functions for different clusters are different. For the coupling scheme, the effects of the coupling are assumed to be only cooperative, i.e., the coupling matrix is a Metzler matrix with zero row sums, and the connections between the same cluster can be few. For this type of coupling, the main difference of this paper with previous works is that the cluster synchronization is realized by pinning control technique. A simple pinning control strategy is proposed and some sufficient criteria to realize cluster synchronization with both static and adaptive control strength are given. Finally, numerical simulations are presented to verify our theoretical results. © 2015 Elsevier B.V.


Ma H.-Y.,Tongji University | Ma H.-Y.,The Key Laboratory of Embedded System and Service Computing | Ma H.-Y.,Nantong University | Zeng G.-S.,Tongji University | Zeng G.-S.,The Key Laboratory of Embedded System and Service Computing
Jisuanji Xuebao/Chinese Journal of Computers | Year: 2012

Attribute-based encryption (ABE) is an effective cryptographic primitive for achieving fine-grained access control of encrypted data. A well-known concern in the ABE system is that malicious users (or traitors) leak their private keys to construct pirate decryption devices and distribute them to illegal users. The existing solutions can only trace the identities of users who leaked their keys, but they can not revoke the leaked keys from the ABE system. This paper proposes an attribute-based encryption scheme for traitor tracing and revocation together (ABTR). We first introduce an ABE scheme with generalized wildcards (GWABE). Under three assumptions of the subgroup decision problem for 3 primes (3P-SDP), we prove that the GWABE scheme is fully secure by using the dual system encryption method. Then we transform the GWABE scheme into an ABTR scheme by using the complete subtree framework. The ABTR scheme is proved to be fully secure, and provides the nice feature of having constant private key size. However, the previous ABE schemes for traitor tracing were only proved secure in the selective model.


Xu J.-C.,Tongji University | Xu J.-C.,The Key Laboratory of Embedded System and Service Computing | Zeng G.-S.,Tongji University | Zeng G.-S.,The Key Laboratory of Embedded System and Service Computing
Tien Tzu Hsueh Pao/Acta Electronica Sinica | Year: 2012

The existed thread-based software watermarking algorithm can only hide a small amount of information and have low efficiency. Aimed to this status, this paper proposes a new software watermarking algorithm based on the relationship between threads. The main idea is to control the interactive relationship between threads which hides software watermarking by modifying the program's source code. This paper gives a formal definition of the concepts such as relation and relation matrix, and a detailed description of the software watermark embedding and extraction process. We also analyze the date rate and fidelity of the algorithm. Various kinds of attacks used in the experiment, results indicate this algorithm has high resistance.

Loading The Key Laboratory of Embedded System and Service Computing collaborators
Loading The Key Laboratory of Embedded System and Service Computing collaborators