检索结果-南通市图书馆

science china(Information sciences) 2011年第3期54卷 469-481页

作者： WANG Nan 1,2, ZHANG TianWu 2 & XU JieQiong 1 1 School of Aeronautic science and engineering, Beijing University of Aeronautics and Astronautics, Beijing 100191, china 2 department of computer science and engineering, henan institute of engineering, zhengzhou 451191, china School of Aeronautic science and engineering Beijing University of Aeronautics and Astronautics Beijing China department of computer science and engineering Henan Institute of Engineering Zhengzhou China

In this paper, several formation controllers are developed with constant and variable connected communication topology for six-degree-of-freedom (6-DOF) networked spacecraft flying in deep space with constant and time-varying communication delays considered. In the control algorithm, any explicit leader does not exist in the formation team and it is required that each spacecraft communicate only with its neighbors and therefore the required communication loads of the whole formation is greatly reduced. The proposed control strategies allow that each spacecraft can track its desired position and attitude and simultaneously the whole group moves to the desired formation and obtain its desired relative attitudes with its neighbors. Simulation results demonstrate the effectiveness of the proposed controllers.

关键词： deep space graph theory formation control communication topology delays

An improved approach to the efficient construction of and search operations in motion graphs

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

science china(Information sciences) 2012年第5期55卷 1042-1051页

作者： GAO Yan 1,CHEN ZhiHua 2,CHEN MinGang 3 & SHEN Yang 3 1 Software engineering institute,East china Normal University,Shanghai 200062,china 2 department of computer science and engineering,East china University of science and Technology,Shanghai 200237,china 3 department of computer science and engineering,Shanghai Jiao Tong University,Shanghai 200240,china Software engineering institute East China Normal University Shanghai China department of computer science and engineering East China University of Science and Technology Shanghai China department of computer science and engineering Shanghai Jiao Tong University Shanghai China

Motion graphs have been widely used as an effective technique in the synthesis of human *** synthesize well-formed motions,motion graphs require smooth transitions and good ***,the time and costs grow quadratically as the graph size *** this paper,we present a method to set up a hierarchical structure,called a structure *** coarse level of this graph models different motion categories and their transitions,and the fine level mainly captures different motion *** interpolation space method is used to improve the graph connectivity at the fine *** structure guides the establishment of a faster and more realistic graphical *** the building process,this structure also helps with searching the motion graph,by performing a traverse search and placing the findings into a direct look-up table or local search ***,when there is no direct link between the different motions,a navigation map is introduced to conduct an appropriate search path via a series of transition motion *** experimental results indicate that our approach could lower the computation time in construction and searching,while simultaneously providing a richer variety of motion styles.

关键词： motion graph structure table registration curve motion interpolation

Distribution of 0 and 1 in the highest level of primitivesequences over Z/(2~e) (Ⅱ)

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Chinese science Bulletin 1998年第8期43卷 633-635页

作者： QI Wenfeng and ZHOU Jinjun department of Applied Mathmatics, zhengzhou Information engineering institute, zhengzhou 450002, china department of Applied Mathmtics Zhengzhou Information Engineering Institute Zhmgzhou China

The distribution of 0 and 1 is studied in the highest level a e-1of primitive sequences over Z/(2\+e). It is proved that the proportion of 0 (or 1) in one period of a e-1is between 40% and 60% for e≥8.

关键词： linear recurring sequence primitive sequence highest levelZ sequence distribution of 0 and 1.

Image stylization with enhanced structure on GPU

在线全文

学校读者我要写书评

暂无评论

science china(Information sciences) 2012年第5期55卷 1093-1105页

作者： LI Ping 1,SUN HanQiu 1,SHENG Bin 1,2 & SHEN JianBing 3 1 department of computer science and engineering,The Chinese University of Hong Kong,Hong Kong,china 2 department of computer science and engineering,Shanghai Jiao Tong University,Shanghai 200240,china 3 School of computer science and Technology,Beijing institute of Technology,Beijing 100081,china department of computer science and engineering The Chinese University of Hong Kong Hong Kong China department of computer science and engineering Shanghai Jiao Tong University Shanghai China School of computer science and Technology Beijing Institute of Technology Beijing China

This paper presents a graphics processing unit (GPU) based stylization approach that preserves the fine structure between the original and the stylized images using gradient *** abstraction and painterly stylization methods focused on contrast manipulation only,and thus the detailed salient structures of the input images are always destroyed when performing the current stylization techniques because of limitations like unavoidable salience information loss caused by contrast *** propose an image structure map to naturally model the fine structure existing in the original ***-based structure tangent generation and tangent-guided image morphology are used to construct the structure *** image structure map,unlike an edge map,not only systematically models the boundary information within the imagery but also accentuates the underlying inner structure detail for further *** facilitate the final stylization via parallel bilateral grid and structure-aware stylizing optimization on a GPU-CUDA platform in real *** multiple experiments,the proposed method consistently demonstrates efficient and high quality image stylization performance.

关键词： image stylization non-photorealistic rendering real-time processing GPU image abstraction

Efficient video cutout based on adaptive multilevel banded method

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

science china(Information sciences) 2012年第5期55卷 1082-1092页

作者： CHEN MinGang 1,SUI BoCong 1,GAO Yan 2 & MA LiZhuang 1 1 department of computer science and engineering,Shanghai Jiao Tong University,Shanghai 200240,china 2 Software engineering institute,East china Normal University,Shanghai 200062,china department of computer science and engineering Shanghai Jiao Tong University Shanghai China Software engineering institute East China Normal University Shanghai China

Although many efficient image cutout approaches have been proposed,it is still a challenge to cut out foreground objects from a video clip because of the costs of time and memory consumption and the difficulty in maintaining temporal coherence for the cutout *** this paper,we propose a novel and efficient video cutout approach by extending a multilevel banded image segmentation method to video *** our method,the segmentation results are propagated frame by frame at the lowest resolution level based on optical flow,and are refined in image pyramids level by level through banded graph *** construct an adaptive narrow band to ensure that the segmentation result falls exactly into the narrow band during *** results show that the video cutout approach based on adaptive multilevel bands dramatically reduces time and memory costs,and achieves ideal segmentation results.

关键词： video object cutout multilevel band graph cuts video segmentation

Study on the key technology of the mobile video display system in the client

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Study on the key technology of the mobile video display syst...

Hybrid particle swarm cooperative optimization algorithm and its application to MBC in alumina production

2011 3rd IEEE International Conference on Information Management and engineering(ICIME 2011)

作者： Xiaoyu Ma department of computer science And engineering henan institute of engineering zhengzhou china Jixun Gao department of computer science And engineering henan institute of engineering zhengzhou china

This paper first describes the characteristics of mobile devices and the popular operating system of Windows CE, Then according to the problems about the resources of mobile devices, improve the key technology of mobile video display system in the client which include the improvement of multi-thread technology, display efficiency of the video image and the transform algorithm of the image resolution. The application of improved technology, not only can make the modules of receiving, decoding and displaying run in parallel, improve the utilization of CPU resources, but also can expedite the processing speed of video, improve the display efficiency of the video image.

关键词： mobile video transform display efficiency algorithm

来源： cnki会议评论

在线全文

cnki会议

学校读者我要写书评

暂无评论

Progress in Natural science:Materials International 2008年第11期18卷 1423-1428页

作者： Shengli Song~(a,b) Li Kong~a Yong Gan~b Rijian Su~(a,b) a department of Control Scienee and engineering,Huazhong University oF science and Technology,Wuhan 430074,china b College of computer and Communication engineering,zhengzhou University of Light Industry,zhengzhou 450002,china department of Control science and engineering Huazhong University of Science and Technology Wuhan 430074 China College of computer and Communication engineering Zhengzhou University of Light Industry Zhengzhou 450002 China

An effective hybrid particle swarm cooperative optimization(HPSCO)algorithm combining simulated annealing method and sim- plex method is *** main idea is to divide particle swarm into several sub-groups and achieve optimization through coop- erativeness of different sub-groups among the *** proposed algorithm is tested by benchmark functions and applied to material balance computation(MBC)in alumina *** show that HPSCO,with both a better stability and a steady convergence,has faster convergence speed and higher global convergence ability than the single method and the improved particle swarm optimization *** importantly,results demonstrate that HPSCO is more feasible and efficient than other algorithms in MBC.

关键词： PSO Simulated annealing Simplex Cooperative optimization

The Young's moduli prediction of random distributed short-fiber-reinforced polypropylene foams using finite element method

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

science china(Technological sciences) 2009年第1期52卷 72-78页

作者： WANG Bo1, WANG RongXiu2 & WU Yong1 1 School of Mathematic science, Chongqing institute of Technology, Chongqing 400050, china 2 department of computer science and Information engineering, Chongqing Technology and Business University, Chongqing 400067, china School of Mathematic science Chongqing Institute of Technology Chongqing China department of computer science and Information engineering Chongqing Technology and Business University Chongqing China

The elastic moduli of short-fiber-reinforced foams depend critically on the fiber content and fiber length, as well as on the fiber orientation distribution. Based on periodic tetrakaidecahedrons, the finite element models with short-fiber reinforcement were proposed in this paper to examine the effects of the fiber content and fiber length on Young's modulus. The fiber length distribution and fiber orientation distribution were also considered. The proposed models featured in a three-dimensional diorama with random short-fiber distribution within or on the surfaces of the walls and edges of the closed-cells of polypropylene (PP) foams. The fiber length/orientation distributions were modeled by Gaussian prob-ability density functions. Different fiber volume fractions, different lengths, and different distributions were investigated. The predicted Young's moduli of the PP foams with short-glass-fiber or short-carbon-fiber reinforcement were compared with other theoretic and experimental results, and the agreement was found to be satisfactory. The proposed finite element models were proved to be acceptable to predict the Young's moduli of the grafted closed-cell PP foams with short-fiber reinforcement.

关键词： short-fiber reinforcement Young’s modulus finite element Gaussian distribution

Electrochemical performance of LiFePO_4 cathode material for Li-ion battery

在线全文

学校读者我要写书评

暂无评论

Rare Metals 2006年第Z1期25卷 62-66页

作者： LI Shuzhong LI Chao FAN Yanliang XU Jiaqiang WANG Tao YANG Shuting engineering Research Centre for New Power Source Materials of henan Province Xinxiang 453002 China Engineering Research Centre for New Power Source Materials of Henan Province Xinxiang 453002 China department of Applied Chemistry College of Material Science and Chemical Engineering Zhengzhou Institute of Light Industry Zhengzhou 450002 China Department of Applied Chemistry College of Material Science and Chemical Engineering Zhengzhou Institute of Light Industry Zhengzhou 450002 China Department of Applied Chemistry College of Material Science and Chemical Engineering Zhengzhou Institute of Light Industry Zhengzhou 450002 China Engineering Research Centre for New Power Source Materials of Henan Province Xinxiang 453002 China Department of Chemical Engineering College of Chemistry and Environmental Science Henan Normal University Xinxiang 453007 China

In the search for improved materials for rechargeable lithium batteries, LiFePO4 offers interesting possibilities because of its low raw materials cost, environmental friendliness and safety. The main drawback with using the material is its poor electronic conductivity and this limitation has to be overcome. Here Al-doped LiFePO4/C composite cathode materials were prepared by a polymer-network synthesis technique. Testing of X-ray diffraction, charge-discharge, and cyclic voltammetry were carried out for its performance. Results show that Al-doped LiFePO4/C composite cathode materials have a high initial capacity, good cycle stability and excellent low temperature performance. The electrical conductivity of LiFePO4 material can be obviously improved by doping Al. The better electrochemical performances of Al-doped LiFePO4/C composite cathode materials have a connection with its conductivity.

关键词： lithium ion batteries LiFePO4 doping electrochemical performance

THE STABILITY OF THE θ-METHODS FOR DELAYDIFFERENTIAL EQUATIONS

在线全文

学校读者我要写书评

暂无评论

Journal of Computational Mathematics 1999年第4期17卷 441-448页

作者： Jing-jun Zhao Ming-zhu Liu(department of mathematics, Harbin institute of Technology, Harbin 150001, china)Shen-shan Qiu(department of computer science and engineering, Harbin institute of Technology, Harbin 150001, china) 哈尔滨工业大学数学系黑龙江哈尔滨 150001 哈尔滨工业大学数学系黑龙江哈尔滨哈尔滨工业大学计算机系黑龙江哈尔滨

This paper deals with the stability analysis of numerical methods for the solution of delay differential equations. We focus on the behaviour of three θ-methodsin the solution of the linear test equation u'(t)-A(t)u(t)+B(t)u( (t)) with (t)and A(t),B(t) continuous matrix functions. The stability regions for the threeθ-methods are determined.

关键词： Delay differential equations Numerical solution Stabilityl θ-methods.