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Yisheng R.,Engineering University of the Armed Police Force
Acta Astronautica | Year: 2013

A CFD study on drag reduction in supersonic flow with opposing jet has been conducted. Flowfield parameters, reattachment point position and surface pressure distributions are obtained and validated with experiments. From the analysis on the physical mechanism of drag reduction, it shows the phenomenon that, when the opposing jet blows, the high pressure region is located between the bow shock wave and the Mach disk, which makes the nose region much lower pressure. As the pressure ratio increases, the high pressure region is gradually pushed away from the surface. Larger the total pressure ratio is, the lower of the drag coefficient is. To study the effect of the intensity of opposing jet more reasonably, a new parameter RPA has been introduced by combining the flux and the total pressure ratio. The study shows that the same shock wave position and drag coefficient can be obtained with the same RPA with different fluxes and the total pressures, which means the new parameter could stand for the intensity of opposing jet and could be used to analyze the influence of opposing jet on flow field and aerodynamic force. © 2013 IAA. Source

Kong W.W.,Engineering University of the Armed Police Force
Electronics Letters | Year: 2013

Presented is a novel technique to fuse multi-sensor images using nonsubsampled shearlet transform (NSST) domain I2CM. First, multiscale and multi-directional decompositions of source images can be performed by NSST. The classic ICM is improved to be I2CM which is then exploited to capture and extract the characteristics of each of the sub-band images. Finally, the fused image is reconstructed from the fused sub-images by adopting the inverse NSST. Experimental results demonstrate that the proposed image fusion scheme is very competitive compared with other conventional ones in both visual effect and objective evaluation criteria. © 2013 The Institution of Engineering and Technology. Source

Hu Y.-J.,Xidian University | Hu Y.-J.,Engineering University of the Armed Police Force | Pei Q.-Q.,Xidian University | Pang L.-J.,Xidian University
Tongxin Xuebao/Journal on Communications | Year: 2015

Pay close attention to the protocol's abnormal behavior, and takes the message raw data and the protocol binary code both as the analysis objects. The proposed method uses dynamic taint analysis combined with static analysis, firstly monitor and analyze the process of protocol program parses the message in our developed virtual platform Abnormal Disc prototype system, and record the protocol's public behavior; then based on the proposed abnormal behavior perception and mining algorithm, static analyze the protocol's abnormal behavior trigger conditions and abnormal behavior instruction sequences. Finally, generate the new protocol messages with the sensitive information according to the abnormal behavior trigger conditions, and dynamic trigger the abnormal behaviors execute. Abnormal Disc prototype system can perceive, trigger and analyze the protocol's abnormal behaviors. According to the statistical analysis results, the evaluation method of protocol execution security was proposed. The experimental results show that the method can accurately mine the protocol's abnormal behavior, and evaluate the protocol's execution security. © 2015, Editorial Board of Journal on Communications. All right reserved. Source

Zhu S.,Engineering University of the Armed Police Force | Yang X.,Engineering University of the Armed Police Force
Journal of Computers (Finland) | Year: 2013

In PKC 2012, a public key encryption based on new multivariate quadratic assumptions is proposed. The compactness and security of the algorithm illumined us in applying it in proxy re-encryption scheme. In this paper, a novel unidirectional PRE scheme (NMQ-PRE) is constructed based on new multivariate quadratic assumptions. The new scheme is a formal PRE scheme and compact in cryptographic protocols. By applying the nature property of multivariate quadratic assumptions, NMQ-PRE is proved chosen ciphertext attack in standard model. Compared with the traditional PRE scheme based on RSA or pairings, NMQ-PRE is computationally efficient and simpler. Finally, a NMQ-PRE scheme for message block is built for application convenience, such as file sharing or mail forwarding. © 2013 ACADEMY PUBLISHER. Source

Gong Q.G.,Xian University of Technology | Wang D.Q.,Engineering University of the Armed Police Force | Yang K.,Engineering University of the Armed Police Force
Applied Mechanics and Materials | Year: 2014

The mass event happens frequently, and once dealt not well, the event will lose control and the result is unimaginable. This paper, based on the analysis of the theory of the emotional contagion, proposes leveled emotional model based on the importance of leaders. By improving the interaction algorithm of the participants, introducing the factors of followers, emotional decline, emotional un-adaption, moving around, we also build an emotional affection model of the mass event. Finally we explore the general rule of the mass event through simulation in the AnyLogic software, which can provide policy when facing mass event. © (2014) Trans Tech Publications, Switzerland. Source

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