He T.,Central University of Finance and Economics |
Chen H.,Equipment Research Institute of PLAs Second Artillery
Proceedings - 2010 International Conference on Computational and Information Sciences, ICCIS 2010 | Year: 2010
According to the affective model based on rough fuzzy sets, this paper presents a new method to mine and analyze affective dynamic transition law. This method combines Markov chain with rough fuzzy sets, and mines affective dynamic transition law in stable environment. The definition of affective entropy enables us to analyze affective dynamic transition law conveniently. Simulation shows that the new method is reasonable. © 2010 IEEE.
Cheng L.-R.,Tsinghua University |
Cheng L.-R.,Equipment Research Institute of PLAs Second Artillery |
Shi H.-J.,Tsinghua University
Hanneng Cailiao/Chinese Journal of Energetic Materials | Year: 2015
In order to characterize the dynamic mechanical behavior of polymer bonded explosives (PBX), a macroscopic elastic-viscoplastic constitutive relation has been developed, coupled by the micromechanical damage mechanism based on the macro crack statistical method. Dynamic compressive and fracture test of the PBX(64%RDX and 20%Al and 16%HTPB) have been carried out, and the material contants and algorithm for the model have been presented. By comparing with the dynamic compressive test data and simulation results of PBX, this model can predict the mechanical deformation process under different loading conditions, so that it can be spread for the deformation analysis of heterogeneous explosives. ©, 2015, Editorial Board of Chinese Chinese Journal of Energetic Materials. All right reserved.
Li L.,China Aerospace Science and Technology Corporation |
Li L.,National University of Defense Technology |
Yu Q.,National University of Defense Technology |
Shang Y.,National University of Defense Technology |
And 3 more authors.
Science China Technological Sciences | Year: 2010
This article presents a passive navigation method of terrain contour matching by reconstructing the 3-D terrain from the image sequence (acquired by the onboard camera). To achieve automation and simultaneity of the image sequence processing for navigation, a correspondence registration method based on control points tracking is proposed which tracks the sparse control points through the whole image sequence and uses them as correspondence in the relation geometry solution. Besides, a key frame selection method based on the images overlapping ratio and intersecting angles is explored, thereafter the requirement for the camera system configuration is provided. The proposed method also includes an optimal local homography estimating algorithm according to the control points, which helps correctly predict points to be matched and their speed corresponding. Consequently, the real-time 3-D terrain of the trajectory thus reconstructed is matched with the referenced terrain map, and the result of which provides navigating information. The digital simulation experiment and the real image based experiment have verified the proposed method. © 2010 Science China Press and Springer-Verlag Berlin Heidelberg.
Zheng Z.-G.,Equipment Research Institute of PLAs Second Artillery |
Xu H.,Beijing Institute of Technology
Dandao Xuebao/Journal of Ballistics | Year: 2014
Aiming at hypersonic vehicles, a terminal guidance law satisfying the final position, dynamic pressure, normal overload constraints as well as the terminal attack direction and terminal velocity constraints, was studied. The optimal feedback control was obtained by solving the nonlinear optimal control problem using Gauss pseudospectral method. An initial guess strategy was imposed into the Gauss pseudospectral solving-process to accelerate the convergence speed. In the last guidance cycle, no feedback information was available. Therefore, the proportional navigation guidance was applied to ensure the impact accuracy. Monte-Carlo shooting experiment of three-degree-of-freedom model was conducted under the conditions of dispersion. The simulation result verifies that the onboard Gauss pseudospectral guidance law is stable and robust even in the highly dispersed cases.
Zhao C.,CAS Research Center for Eco Environmental Sciences |
Wang X.,Equipment Research Institute of PLAs Second Artillery |
He J.,CAS Research Center for Eco Environmental Sciences |
Luan Z.,CAS Research Center for Eco Environmental Sciences |
And 2 more authors.
Chinese Journal of Chemical Engineering | Year: 2010
In this paper a polyaluminum chloride solution with high Al13 content was prepared and used as raw material for preparation of γ-Al 2O3. The texture and crystalline phase of the prepared alumina samples were characterized by energy dispersive X-ray spectroscopy (EDX), X-ray diffraction, transmission electron microscope (TEM) and nuclear magnetic resonance (NMR) analyses. The effects of alkaline solution and calcination temperature were investigated. The results showed that alkaline solution including NH3·H2O and NaOH had little effect on the alumina sample formation. The impurities of NH4Cl and NaCl in solution can be removed through repeated washing by EDX analysis. Calcination temperature had a significant effect on alumina crystal phase. The alumina sample can transform completely to γ-Al2O3 in the subsequent heating from 600 °C to 800 °C. It is very interesting that Al13 can be existed in γ-Al2O3 phase even after calcinations. The results indicate that polyaluminum chloride with high Al13 content is an effective material to prepare γ-Al 2O3. © 2010 Chemical Industry and Engineering Society of China (CIESC) and Chemical Industry Press (CIP).