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Displacement residual based DDM matching algorithm

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Science china(Information Sciences) 2012年第9期55卷 2090-2101页

作者： ZHANG Lin 1,2,ZHOU Zhong 1,2,LIU Lin 1,2 & WU Wei 1,2 1 state key laboratory of Virtual Reality technology and systems,Beihang University,beijing 100191,china 2 School of Computer Science and Engineering,Beihang University,beijing 100191,china state key laboratory of Virtual Reality technology and systems Beihang University Beijing China School of Computer Science and Engineering Beihang University Beijing China

High level architecture(HLA) is the prevailing standard for modeling and *** data distribution management(DDM) service of HLA is defined for reducing the delivery of irrelevant *** key in DDM implementation is the region overlap computation,*** matching between update and subscription *** algorithms usually make a compromise between region fidelity and network *** paper takes both the matching algorithm efficiency and bandwidth cost into *** main contributions are:1) illustrating the relationship between region changes and overlap changes,as helps reduce the number of region matching and then improves the total matching efficiency;2) classifying region updates into two types of data expression,snapshot and *** network traffic will be reduced by transmitting only residual data instead of full region representations ***,a region matching algorithm called displacement residual-based DDM matching(DRBM) is proposed in the *** analysis,algorithm implementation and experiment evaluation are *** results show that DRBM provides better matching performance and significant network payload reductions especially when there is a large number of changing regions.

关键词： distributed simulation high level architecture data distribution management region snapshot region residual

A study on compressive shock wave propagation in metallic foams

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Science china(Physics,Mechanics & Astronomy) 2010年第2期53卷 279-287页

作者： WANG ZhiHua1,2,ZHANG YiFen2,REN HuiLan1 & ZHAO LongMao2 1 state key laboratory of Explosion Science and technology,beijing Institute of technology,beijing 100081,china 2 Institute of Applied Mechanics and Biomedical Engineering,Taiyuan University of technology,Taiyuan 030024,china state key laboratory of Explosion Science and technology Beijing Institute of Technology Beijing China Institute of Applied Mechanics and Biomedical Engineering Taiyuan University of Technology Taiyuan China

Metallic foam can dissipate a large amount of energy due to its relatively long stress plateau,which makes it widely applicable in the design of structural crashworthiness. However,in some experimental studies,stress enhancement has been observed when the specimens are subjected to intense impact loads,leading to severe damage to the objects being protected. This paper studies this phenomenon on a 2D mass-spring-bar model. With the model,a constitutive relationship of metal foam and corresponding loading and unloading criteria are presented; a nonlinear kinematics equilibrium equation is derived,where an explicit integra-tion algorithm is used to calculate the characteristic of the compressive shock wave propagation within the metallic foam; the effect of heterogeneous distribution of foam microstructures on the shock wave features is also included. The results reveal that under low impact pulses,considerable energy is dissipated during the progressive collapse of foam cells,which then reduces the crush of objects. When the pulse is sufficiently high,on the other hand,stress enhancement may take place,especially in the heterogeneous foams,where high peak stresses usually occur. The characteristics of compressive shock wave propagation in the foam and the magnitude and location of the peak stress produced are strongly dependent on the mechanical properties of the foam material,amplitude and period of the pulse,as well as the homogeneity of the microstructures. This research provides valuable insight into the reliability of the metallic foams used as a protective structure.

关键词： aluminum foam heterogeneous intensive pulse loading stress enhancement

Modified chaotic ant swarm to function optimization

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The Journal of china Universities of Posts and Telecommunications 2009年第1期16卷 58-63页

作者： LI Yu-ying , WEN Qiao-yan, LI Li-xiang state key laboratory of Networking and Switching technology, beijing University of Posts and Telecommunications, beijing 100876, china state key laboratory of Networking and Switching technology Beijing University of Posts and Telecommunications Beijing 100876 China

The chaotic ant swarm algorithm （CAS） is an optimization algorithm based on swarm intelligence theory, and it is inspired by the chaotic and self-organizing behavior of the ants in nature. Based on the analysis of the properties of the CAS, this article proposes a variation on the CAS called the modified chaotic ant swarm （MCAS）, which employs two novel strategies to significantly improve the performance of the original algorithm. This is achieved by restricting the variables to search ranges and making the global best ant to learn from different ants＇ best information in the end. The simulation of the MCAS on five benchmark functions shows that the MCAS improves the precision of the solution.

关键词： chaotic ant swarm benchmark functions modified chaotic ant swarm swarm intelligence

Automatic composition of information-providing web services based on query rewriting

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Science china(Information Sciences) 2012年第11期55卷 2428-2444页

作者： ZHAO WenFeng,LIU ChuanChang & CHEN JunLiang state key laboratory of Networking and Switching technology,beijing University of Posts and Telecommunications,beijing 100876,china state key laboratory of Networking and Switching technology Beijing University of Posts and Telecommunications Beijing China

Compared with normal web services,information-providing services have unique features that have seldom been considered in existing research on the automatic composition of web *** this paper,we present a simple,yet well-formed,semantic-based capability model for information-providing web services,which can express such features as not modifying the world state and not requiring all input/output parameters to be supplemented with class information as *** then present a corresponding automatic composition method derived from a query rewriting algorithm,MiniCon,used in the data integration *** method adequately utilizes previous features,enables primitive semantic reasoning,and can generate executable BPEL scripts *** of the method is complementary to traditional search-based *** on a typical type of problem show that the method is usable in practice.

关键词： web services automatic composition query rewriting data integration ontology semantic web

Competent predicate abstraction in model checking

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Science china(Information Sciences) 2011年第2期54卷 258-267页

作者： LI Li1,2,3, SONG XiaoYu4, GU Ming2,3 & LUO XiangYu2,3 1Department of Computer Science & technology, Tsinghua University, beijing 100084, china 2key laboratory for Information System Security, Ministry of Education of china, beijing 100084, china 3School of Software, Tsinghua University, beijing 100084, china 4Department of ECE, Portland state University, Portland, Oregon 97207, USA Department of Computer Science & technology Tsinghua University Beijing China key laboratory for Information System Security Ministry of Education of China Beijing China School of Software Tsinghua University Beijing China Department of ECE Portland State University Portland USA

The paper presents a new approach to computing the abstract state and a maximum weight heuristic method for finding the shortest counter-example in verification of imperative programs. The strategy is incorporated in a verification system based on the counterexample-guided abstraction refinement method. The proposed method slashes both the size of the abstract state space and the number of invokes of a decision procedure. A number of benchmarks are employed to evaluate the effectiveness of the approach.

关键词： program model checking predicate abstraction weight heuristic

The correspondence between the concepts in description logics for contexts and formal concept analysis

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Science china(Information Sciences) 2012年第5期55卷 1106-1122页

作者： MA Yue 1,2,SUI YueFei 1 & CAO CunGen 1 1 key laboratory of intelligent Information Processing,Institute of Computing technology,Chinese Academy of Sciences,beijing 100190,china 2 Graduate University of Chinese Academy of Sciences,beijing,china key laboratory of intelligent Information Processing Institute of Computing Technology Chinese Academy of Sciences Beijing China Graduate University of Chinese Academy of Sciences Beijing China

Formal concept analysis (FCA) and description logic (DL) are meant to be formalizations of concepts.A formal concept in the former consists of its intent and extent,where the intent is the set of all the attributes shared by each object in the extent of the concept,and the extent is the set of all the objects sharing each property in the intent of the concept.A concept in the latter formalization is simply a concept name,the interpretation of which is a subset of a *** consider the correspondence between concepts in both formalizations,a multi-valued formal context must be represented both as a knowledge base and as a model of the DL for contexts,where concepts are decomposed into tuple concepts C,interpreted as a set of tuples and value concepts V,interpreted as a set of attribute-value *** show that there is a difference between the interpretation of concepts R.V /R.C and the Galois connection between the extent/intent of formal concepts in *** to the Galois connection,there should be concepts of the form + R.V and + R.C inter-preted in FCA,and hence the logical language L for DL is extended to be L + together with + as a constructor so that + R.V and + R.C are well-defined ***,according to the interpretation in DL there should be pseudo concepts in FCA so that the interpretation of concepts R.V /R.C is the extent/intent of pseudo *** correspondence between formal concepts and concepts in L +,and between pseudo concepts and concepts in L are presented in this paper.

关键词： description logic formal concept analysis concept attribute/role

Third-order point contact approach for five-axis sculptured surface machining using non-ball-end tools (Ⅰ): Third-order approximation of tool envelope surface

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Science china(Technological Sciences) 2010年第8期53卷 1904-1912页

作者： ZHU LiMin1, DING Han2 & XIONG YouLun2 1 state key laboratory of Mechanical System and Vibration, Shanghai Jiao Tong University, Shanghai 200240, china 2 state key laboratory of Digital Manufacturing Equipment and technology, Huazhong University of Science and technology, Wuhan 430074, china state key laboratory of Mechanical System and Vibration Shanghai Jiao Tong University Shanghai China state key laboratory of Digital Manufacturing Equipment and technology Huazhong University of Science and Technology Wuhan China

In this paper, the geometric properties of a pair of line contact surfaces are investigated. Then, based on the observation that the cutter envelope surface contacts with the cutter surface and design surface along the characteristic curve and cutter contact (CC) path, respectively, a mathematical model describing the third-order approximation of the cutter envelope surface according to just one given cutter location (CL) is developed. It is shown that at the CC point both the normal curvature of the normal section of the cutter envelope surface and its derivative with respect to the arc length of the normal section can be determined by those of the cutter surface and design surface. This model characterizes the intrinsic relationship among the cutter surface, cutter envelope surface and design surface in the neighborhood of the CC point, and yields the mathematical foundation for optimally approximating the cutter envelope surface to the design surface by adjusting the cutter location.

关键词： five-axis NC machining rotary cutter cutter envelope surface normal curvature third-order point contact

Experimental study on fire smoke movement in a multi-floor and multi-room building

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Science china(Technological Sciences) 2005年第3期48卷 292-304页

作者： ZHONG Maohua 1, 2 , LI Peide 2 , LIU Tiemin 1 , WEI Xing 1, 2 & LIAO Guangxuan 2 1. National Center of Safety Science and technology, state Administration of Work Safety, beijing 100029, china 2. state key laboratory of Fire Science, University of Science and technology of china, Hefei 230026, china National Center of Safety Science and technology State Administration of Work Safety Beijing China state key laboratory of Fire Science University of Science and Technology of China Hefei China

Fire smoke movement of multi-floor and multi-room (MFMR) fire was studied at the model test building in state key laboratory of Fire Science (SKLFS). The ingredient, temperature, air pressure difference and air velocity of smoke were measured and analyzed. Meanwhile, the hazard of smoke ingredient to exposed occupants was analyzed based on the national standard, Occupational Exposure Limit for Hazardous Agents in the Workplace (GBZ2-2002). The experimental results showed that the maximum temperature difference in MFMR fire was located along the vertical height from the fire source. With the spreading and diffusion of smoke, the temperature of smoke layer would tend to be no difference. In the fire of woodpile and kerosene, the main smoke ingredients such as SO 2 , CO and CO 2 would first exceed human’s average physiological limit, while smoke ingredients such as NO and NO 2 would come behind. Because of the higher fluctuation range and frequency of air pressure difference of smoke in multi-layer building fire, the fire smoke would spread around everywhere of the passageway and made the human evacuation more difficult.

关键词： multi-floor and multi-room,fire experiment,smoke spread,smoke toxicity.

Wide/narrow azimuth acquisition footprints and their effects on seismic imaging

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Petroleum Science 2008年第4期5卷 308-313页

作者： Di Bangrang Xu Xiucang Wei Jianxin key laboratory of CNPC Geophysical Exploration China University of Petroleum Beijing 102249 China state key laboratory of Petroleum Resource and Prospecting China University of Petroleum Beijing 102249 China key laboratory of Earth Prospecting and Information technology China University of Petroleum Beijing 102249 China

Acquisition footprint is a new concept to describe the seismic noise in three-dimensional seismic exploration and it is closely related to geometry and observation shuttering. At present, the study on acquisition footprints has become a hot spot. In partnership with the Dagang Oilfield, we used the channel sand body seismic physical model to study the characteristics of wide/narrow azimuth acquisition footprints and analyzed and compared the two types of footprints and their effects on target imaging. In addition, the footprints caused by data processing of the normal moveout offset （NMO） stretching aberration were discussed. These footprints are located only in the shallow or middle layer in the time slice, and possibly affect the imaging of shallow target layers, and have no influence on deep target imaging. Seismic physical modeling has its advantages in the study of acquisition footprints.

关键词： Wide/narrow azimuth geometry acquisition footprint stretching aberration time slice seismic imaging