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Beijing, China

Li T.,Beijing Simulation Center | Li B.-H.,Beihang University | Chai X.-D.,Beijing Simulation Center
Jisuanji Jicheng Zhizao Xitong/Computer Integrated Manufacturing Systems, CIMS | Year: 2012

According to the characteristics of multi-granularity resources sharing and simulation services establishment as well as its new demand on Simulation Service Description Framework(SSDF) in cloud simulation, a layered SSDF oriented to cloud simulation was proposed. The semantics of each layer in the framework were defined and formalized in OWL-S, and the researches were applied to the description of simulation services in certain cloud simulation system prototype. The proposed layered SSDF was verified by typical example. The result showed that the layered SSDF oriented cloud simulation was suitable for various multi-granularity simulation resources of cloud simulation system, and could described cloud simulation services in both attribute-semantic and model-semantic. Thus the intelligent discovery and automatic combination of simulation services were supported, and the construction of cloud simulation mode was realized.

Xie X.,Beihang University | Li B.,Beihang University | Chai X.,Beijing Simulation Center
Journal of Information Hiding and Multimedia Signal Processing | Year: 2016

Sensory data classification is a crucial task in many information processing. The vector data or matrix data are the most common data format, especially matrix data, for example, image data. We propose Gaussian kernel constructing method adaptive to the distribution of the input data for classification. In the current matrix based feature extraction, the matrix image is transformed to the vector, and the procedure of transforming will increase the ability of a large saving space and computing. And secondly the different geometrical structures under the different kernel function will bring the different class discrimination of the input data in the feature space. The performance of kernel will be increased under the adaptive choosing the parameters of kernel. We present the matrix Gaussian kernel, Quasiconformal matrix Gaussian kernel, and Quasiconformal matrix multikernels, and we implement the three kinds of kernels on different classifiers on ORL and Yale image databases. The experimental results show that the proposed kernels perform better than the traditional kernel functions. © 2016.

Xie X.,Beihang University | Li B.,Beihang University | Chai X.,Beijing Simulation Center
Journal of Information Hiding and Multimedia Signal Processing | Year: 2015

Hyperspectral Imagery Sensing (HIS) is widely gained tremendous popularity in many research areas such as remotely sensed satellite imaging and aerial reconnaissance. HIS is an important technique with the measurement, analysis, and interpretation of spectra acquired sensing scene an airborne or satellite sensor. The development of sensor technology brought the developing of collecting image data using hyperspectral instruments with hundreds of contiguous spectral channels. The preprocessing of hyperspectral sensing data is a feasible way through machine learning technology. Among these machine learning methods, kernel learning is a feasible nonlinear feature extraction on hyperspectral sensing data. The nonlinear problems are solved with kernel function, and system performances such as recognition accuracy, prediction accuracy are largely increased. In this paper, we present a novel Kernel-Based Nonparametric Fisher Classifier (KNFC) for hyperspectral remote sensing imagery. Firstly, we have a comprehensive theoretical analysis on Nonparametric Discriminant Analysis. And NDA has its limitations on extracting the nonlinear features owing to the high nonlinear and complex distribution of the hyperspectral imagery data. In order to improve the limitation of NDA on hyperspectral remote sensing imagery, we introduce the kernel trick to NDA to develop Kernel-Based Nonparametric Fisher Classifier to enhance its ability on hyperspectral Imagery Sensing data. The feasibility of the KNFC is testified on the ORL and YALE databases, and then some experiments are implemented on two real data sets including Indian Pines and Washington, D.C. Mall, with various spectral and spatial resolutions reflecting different environments of remote sensing. © 2015 ISSN.

Xiao S.,Beihang University | Xudong C.,Beijing Simulation Center | Li Z.,Yunnan University | Guanghong G.,Beihang University
Simulation Modelling Practice and Theory | Year: 2010

This paper presents a modeling framework for product lifecycle information. Although being widely used in enterprises' virtual product data management, Product Lifecycle Management (PLM) systems are unable to manage the modeling and simulation aspects of virtual products. To reinforce the sharing and management of the product lifecycle information, especially the simulation data, a product's four-dimensional (4D) view model (PLIM) is established, which includes geometry view, task view, virtual prototype system view and lifecycle view. To provide efficient and effective simulation information, the prototype system view is then studied in detail. Finally, to validate the feasibility of the modeling framework, a prototype system is developed based on an application example, with the demonstration of 4D product lifecycle information model (PLIM). © 2010 Elsevier B.V. All rights reserved.

Zhao M.-Y.,Beijing Institute of Electronic System Engineering | Wei M.-Y.,Beijing Institute of Electronic System Engineering | He Q.-R.,Beijing Simulation Center
Yuhang Xuebao/Journal of Astronautics | Year: 2010

For the missile controlled by the combination of lateral jet thrusters and aerodynamic fins, the control system is designed. The lateral jet thrusters can improve the response speed, but the structure of control system becomes more complex. Therefore, how to design control strategy properly is a urgent problem. For the aerodynamic fins controlled loop, a missile object with good performance is obtained by solving a minimum time control problem based on the concept of finite time stability. Furthermore, the lateral jet control law based on the backstepping approach is studied, and the control system with faster response can be achieved. In the whole process of design, the response property of the system is improved by adding an 'implicit angle-of-attack' feedback. Finally, the effectiveness of the proposed approach is validated by numerical simulation.

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