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Zheng L.,Logistics Command Academy | Li J.,Aisino Corporation | Liu X.-K.,Academy of Military Transportation | Wang C.-W.,Logistics Command Academy
Xitong Fangzhen Xuebao / Journal of System Simulation | Year: 2010

The ideas and method about the realization of a scene simulation platform using Visual C++ and Direct SDK were introduced. The platform adopted the overall structure of "twin platform based on the shared core", and reusable framework and mechanism for the further development were founded. Three-tier design pattern of "function entity, collection management and user interface" improved code reusing. So the complexity of the problem was reduced, and the software development efficiency was improved. In this scene simulation platform, the management mechanism of extensible visual object was established, the display optimization of medium or small scene and rapid terrain-matching were realized, the functions of particle system-based special effects about rain, snow, smog and blast, etc, and creating, editing, playing and saving key frame animation were achieved. Finally, the applied example was researched.


Wei Z.-H.,Beijing Jiaotong University | Wei Z.-H.,Logistics Command Academy | Wang M.-S.,Beijing Jiaotong University | Zhang D.-L.,Beijing Jiaotong University
Gongcheng Lixue/Engineering Mechanics | Year: 2012

The structural soil strength has always been an important issue in the soil and rock research. The soil and rock is structurally complicated, with a particle chain structure formed by the interconnection of soil particles as one of the dominant morphologies. The analysis for the formation conditions of the particle chain structure of a general type and a friction type is made through building a soil particle chain model, which is used to obtain the conditions for the friction-type particle chain to become stable. On this basis, we attempt to work out soil strength theory for a stable particle chain. It is found from the analysis that the conditions for friction-type soil particles to form a stable chain are related to the fabric relationship of particle composition and also to particle morphology; the strength of a particle chain can influence the soil macro-strength; the length, density and directional distribution of stable particle chains in the soil are important factors for soil strength and also important parameters to characterize the above-mentioned soil structure. The nature of friction-type particle materials to withstand the load is revealed from a particular perspective based on this soil strength theory for a stable particle chain.


Yuan Q.,Logistics Command Academy | Xu Y.,Logistics Command Academy | Song A.,Logistics Command Academy
Procedia Environmental Sciences | Year: 2011

This article begins with an exploratory problem of air refueling support, and by use of a heuristic modeling method, it calculates the maximum operational distance of the main fighter under three situations, which are once-takeoff and multi-takeoff for flying tanker respectively. The center of gravity of this article lies in that we strive to design the optimum program to group the flying tanker fleet and then control the air refueling opportunities. Heuristic rules and mathematical tools are mainly used to achieve our target. © 2011 Published by Elsevier Ltd.


Liu X.-L.,Logistics Command Academy | Liu X.-L.,National University of Defense Technology | Zhang K.-L.,National University of Defense Technology | Guo B.,National University of Defense Technology
Guti Huojian Jishu/Journal of Solid Rocket Technology | Year: 2010

For solving the problem of long calculation time when high accuracy simulation model was used in MDO analysis in complex systems, Gaussian Process Surrogate mode was proposed. Gaussian Process surrogate model theory was proposed, and its flow chart was analyzed in detail. Through example analysis, Gaussian Process surrogate model was proven better than anther two existing surrogate models. It shows that local surrogate models are special cases of Gaussian Process Surrogate mode, which will be the focus of investigation.


Zhang K.-L.,National University of Defense Technology | Liu X.-L.,Logistics Command Academy | Guo B.,National University of Defense Technology
Jisuanji Jicheng Zhizao Xitong/Computer Integrated Manufacturing Systems, CIMS | Year: 2011

To estimate the product design time more precisely, the modeling methodology of Gaussian process meta-model was applied to estimate the product design time. The modeling principles of Gaussian process meta-model were firstly introduced. Since there were linguistic variables among the factors effecting product design time, Hausdorff distance was applied to assist the construction of relevant matrix in Gaussian Process modeling. The example analysis illustrated that Gaussian Process meta-model was superior to the existing two fuzzy neural network models.


Yuan Q.,Logistics Command Academy | Xu Y.,Logistics Command Academy | Song A.,Logistics Command Academy
Applied Mechanics and Materials | Year: 2012

Air refueling technique, which has been developing for a century, displays much more important strategic significance and wider application prospect on operation and material transport in nowadays. This article begins with an exploratory problem, and by use of a modeling method, it calculates the maximum operational distance of the main fighter under once-takeoff situation for flying tanker. The key point of this article lies in that we strive to design the optimum program to group the flying tanker fleet and then control the air refueling opportunities. Heuristic rules and mathematical tools are mainly used to achieve our target. © (2012) Trans Tech Publications.


Wei Z.-H.,Beijing Jiaotong University | Wei Z.-H.,Logistics Command Academy | Wang M.-S.,Beijing Jiaotong University | Zhang D.-L.,Beijing Jiaotong University
Yantu Lixue/Rock and Soil Mechanics | Year: 2012

The fractal structure is a common phenomenon of soil. Through analyzing influence domain(Voronoi domain) of the fractal structure connection point, the bearing capacity of particle connection is converted to stress intensity. Some beneficial results are obtained. Values of fractal dimension of particle system structure influence soil strength obviously. The particle of basic unit is more, the ring from the particle is longer, the space for the ring is larger; it is more instable in mechanical property, the strength is lower. The stage number of fractal structure determines the size of the maximum pore. The stage number of fractal structure is more, the size of the maximum pore is larger, the equivalent stress intensity is lower. The couple stress intensity is inversely proportional to the area of basic structure unit (two-dimensional). That is to say, the basic structure unit is larger, the couple stress intensity is lower. Therefore, it can be concluded that the particle is larger, the couple stress intensity is lower when other conditions are same.


Wei Z.-H.,Logistics Command Academy | Wei Z.-H.,Beijing Jiaotong University | Wang M.-S.,Beijing Jiaotong University | Zhang D.-L.,Beijing Jiaotong University
Gongcheng Lixue/Engineering Mechanics | Year: 2015

Strength and stability of soil mass, far more complex than those of metals, are two major and heatedly discussed issues in soil mechanics. Various strength models have been published in literature. However, most models are associated with assumptions or rely on experimental analysis with limitations, with fundamental theories insufficiently explored. In this study, a hat model which is similar to the Cambridge strength model is proposed based on the studies of soil mass with random uniform mesh particle chain structure. Various strength curves on the π plane have been derived subjected to different assumptions. The most conservative case can be represented by a hat model with a strength curve being regular hexagon on the π plane and parabolic in the longitudinal direction. When the particle chain is damaged and the length of the chain is becoming shorter, vertices of the strength curve move towards infinity, and form a curve with an opening. That is, the Cambridge hat model is transformed into the conical Mohr-Coulomb model. The long particle chain model essentially unifies the Cambridge strength model and the Mohr-Coulomb model. ©, 2015, Tsinghua University. All right reserved.


Wei Z.-H.,Beijing Jiaotong University | Wei Z.-H.,Logistics Command Academy | Wang M.-S.,Beijing Jiaotong University | Zhang D.-L.,Beijing Jiaotong University
Yantu Lixue/Rock and Soil Mechanics | Year: 2013

Many scholars have performed a large amount of researches on soil strength with considerable achievements. But the influence of soil structure on its strength has always been the difficult point. A soil structure strength model is established based on soil particle connection. From the analysis of this soil structure model established, it is found that the strength of soil mass is directly associated with the connection strength among particles and the distribution pattern of connections. When the stress-strength curve family in statistical domains is used to macroscopically analyze the soil mass properties, the yield surface composed of several curved surfaces can be gained. The analysis of examples of simplified soil structure morphology indicates that an isotropic stress-strength model can be obtained when the connection in each direction is evenly distributed. In addition, when the spatial characteristics of statistical domains are considered, for different local coordinates of macroscopic stress in the statistical domain, the stress gradient may influence the soil strength. This is exactly what the classical theories can not explain. Therefore, the strength model of soil structure being established is a kind of new and effective analysis method for structural soil.


Zhao H.,Logistics Command Academy | Yang L.,Logistics Command Academy
Proceedings - 2010 IEEE 2nd Symposium on Web Society, SWS 2010 | Year: 2010

"Web 2.0" refers to a second generation of web-based communities and online services, such as social-networking sites, wikis, and social indexing sites, which enable creativity, collaboration and sharing between users .With the rapid development of "Web 2.0", network education is changing a lot. In contrast to traditional LMS-driven VLE solutions, PLE based on web2.0 takes a more natural and learner-centric approach and is characterized by the freeform use of a set of lightweight services and tools that belong to and are controlled by individual learners. PLEs based on Web2.0 tools consist of three parts. They are knowledge digging, knowledge coding and knowledge shifting. So PLEs are not an application but rather a new approach to the use of new technologies for learning. © 2010 IEEE.

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