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Zhang S.,Luoyang University of Foreign Languages | Cheng Q.,Luoyang University of Foreign Languages | Cheng Q.,China Institute of Technology | Wang X.,Air Defense Forces Command Academy
Proceedings - 2010 WASE International Conference on Information Engineering, ICIE 2010 | Year: 2010

In 2009, Hölbl et al. proposed two new identity-based authenticated key exchange protocols and claimed that their protocols can withstand various attacks. In this paper, we will show that Hölbl et al.'s protocols cannot resist basic impersonation attack. It also means that their protocols are vulnerable to key compromise impersonation (KCI) attacks. Furthermore, we propose improvements of their protocols with impersonation attack resilience and KCI resilience. © 2010 IEEE.

Chen Y.,Zhengzhou Institute of Aeronautical Industry Management | Zhang C.,Air Defense Forces Command Academy
International Journal of Digital Content Technology and its Applications | Year: 2011

The independent component analysis (ICA) algorithm and ICA basic model were studied in detail in this paper. We mainly discussed the mathematical theory of ICA and Fast ICA algorithm of the most widely used at home and abroad. Then, we carried out simulation in blind sources process of the mixing images. Through simulation of three color images (640*480) mixed by a 3*3 random matrix, and using the Fast ICA separation algorithm, we realized the mixed blind source separation. The simulation experiment results show that the Fast ICA algorithm can gain a good approach effect, and the separation image is basical consistent with the original image.

Cheng H.-W.,Air Defense Forces Command Academy | Chen L.,Jiangsu University | Wu L.-N.,Nanjing Southeast University
Xi Tong Gong Cheng Yu Dian Zi Ji Shu/Systems Engineering and Electronics | Year: 2010

Information fusion technique is utilized for modulation classification and a weighted voting algorithm is presented. Firstly, this algorithm defines a contribution to classification results to describe performance improvement of multisystems and depends on it to assign weights for each system. And then the modulation classification of multisystems is modeled as cooperative games and the weights are decided by Shapley value of cooperative games. Finally, by using the weighted voting algorithm presented, decision fusion results of modulation classification is processed. Computer simulation demonstrates an effective improvement in recognition performance via this algorithm.

Shi W.,Nanjing Institute of Technology | Zhang Q.,Military Representative Office Stationed in the 710 Factory | Du H.,Air Defense Forces Command Academy
2010 International Conference on Microwave and Millimeter Wave Technology, ICMMT 2010 | Year: 2010

This paper studies pattern optimization of an offset parabolic reflector antenna with phased array feeds. Considering quantization requirements, to solve optimum weight vector of phased array feeds can be modeled as integer programming problem, which is optimized with the quantum particle swarm optimization (QPSO) algorithm. The optimization with QPSO to determine the quantized element weights is found to yield excellent performance of an offset parabolic reflector antenna, with limited beam electronically scanning and nulling capability. Numerical results of convergence for the QPSO algorithm and the classical particle swarm optimization (CPSO) algorithm are shown and discussed. © 2010 IEEE.

Li P.,Nanjing University of Science and Technology | Chen Q.,Nanjing University of Science and Technology | Zheng H.,Air Defense Forces Command Academy | He B.,Air Defense Forces Command Academy
Hongwai yu Jiguang Gongcheng/Infrared and Laser Engineering | Year: 2011

Small targets detection in the complex background is one of key techniques for infrared imaging system. Thus, different kinds of algorithm are needed in detection according to the difference of target's characters and environment. In order to reduce the complexity of operation and improve real-time performance of infrared surveillance system, a pretreatment method of small targets infrared image based on scanning infrared surveillance system was put forward after analyzing the characters of small targets infrared image. Using this method, the small tagrets and background in the neighborhood unions were detached based on features of seed pixel, and then the noise was suppressed and contrast of image was enhanced. The experimental result shows that the algorithm can improve the SNR of image and reduce complexity of operation, and is very useful in algorithm for small target detection.

Wang Q.,Shenzhen University | Huang J.,Shenzhen University | Huang J.,Air Defense Forces Command Academy
Journal of Intelligent and Fuzzy Systems | Year: 2015

A fuzzy logic-based multi-factor aided multiple-model filter (FLMAMMF) for General aviation (GA) maneuvering target tracking (MTT) is presented. The target category and meteorological information are introduced into the interacting multiple model (IMM) filter to perform GA target tracking. Fuzzy logic inference is employed in the proposed algorithm to reflect the complicated relationship between these two factors and the transition probability matrix (TPM). Both the number of models in model set and the transition probabilities between models are adjusted through fuzzy inference. Simulation results show that the proposed method is efficient and effective. © 2015 - IOS Press and the authors. All rights reserved.

Su Y.,Air Defense Forces Command Academy | Liu X.,Air Defense Forces Command Academy | Li D.,Air Defense Forces Command Academy | Wang X.,Air Defense Forces Command Academy | Zhang Y.,Air Defense Forces Command Academy
Advanced Materials Research | Year: 2011

Impact localization is one of the major concerns in maintenance of aircraft structures built from composites. A lot of different techniques like acoustic emission, optimization technique based on system are nowadays investigated to identify impact location. But the method to identify impact position in complex composite structure with high accuracy in real time has not been completely established. In the present work, a new efficient method is proposed for identifying impact location in real and complex composite structure based on array signal processing and Lamb waves. There are two steps in the proposed method. The first step is to estimate the directionof- arrival (DOA) of impact source using continuous wavelet transform (CWT) and array signal processing; the second step is to estimate the distance between impact source and the coordinate origin based on propagation characteristic of Lamb wave and CWT. The composite panel with stepped thickness of a real and complex aeronautical tank is used to verify the present methodology. The result shows that the present method may identify impact location fast and accurately. © (2011) Trans Tech Publications.

Wan M.,Air Defense Forces Command Academy | Li P.,Shenzhen University | Li T.,Air Defense Forces Command Academy
2010 WRI International Conference on Communications and Mobile Computing, CMC 2010 | Year: 2010

The interacting multiple model (IMM) algorithm is specially designed to track accurately targets whose state and measurement models changes during motion transition. However, when these models are nonlinear, the IMM algorithm must be modified in order to guarantee an accurate track. Recently, the cubature Kalman filter (CKF) has been proposed to estimate the nonlinear system, and could perform better than unscented Kalman filter (UKF). In this paper, the IMM algorithm CKF based (IMM-CKF) is presented to track the maneuvering target using angular measurements. The simulation results demonstrate the improved performance of IMM-CKF over IMM-UKF, and the execution time of the former algorithm is shorter than the latter. © 2010 IEEE.

Wang X.,Air Defense Forces Command Academy | He J.,Air Defense Forces Command Academy
World Automation Congress Proceedings | Year: 2012

In the FLIR automatic infrared object tracing system, the gradient histogram of the FLIR image is unimodality based on tremendous statistics of the gradient histogram of FLIR image. Moreover the gradient histogram of both objects and background can be fitted by χ2 distribution density function with different degree of freedom. According to the above statistical characteristics of the gradient histogram and the least error-classified probability, an automatic estimation method of gradient histogram segmentation threshold is presented and validated in this paper. And the average gradient is the approximation of the optimal segmentation threshold through theoretical analysis. Finally this method is proved to be effective and practical by the segmentation experiments of the FLIR image in the real conditions. © 2012 TSI Press.

Wang P.,Shenzhen University | Xie W.-X.,Shenzhen University | Liu Z.-X.,Shenzhen University | Li P.-F.,Air Defense Forces Command Academy
Tien Tzu Hsueh Pao/Acta Electronica Sinica | Year: 2012

To solve the problem of multi-target tracking model with the time-varying number of targets, a novel Gaussian mixture PHD filter is proposed for the nonlinear Gaussian system. A third-degree Spherical-Radial rule is applied to calculate the prediction and update distributions of target states for nonlinear multi-target models. The pruning method is optimized by using a fuzzy threshold to avoid the exponential increasing of the Gaussian components. The measurements are used to generate the density of new targets that appear randomly anywhere in the observation space. The performance of the four nonlinear Gaussian Mixture PHD filters is compared. The simulation results demonstrated the efficiency of the proposed algorithm.

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