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Local segment-shared protection based on source egress gateway selection for multi-domain optical mesh networks

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Science china(Information Sciences) 2011年第2期54卷 227-235页

作者： ZHANG ShengFeng1,3, PENG YunFeng1,2. DU Shu1, YANG XiaoLong1,2.& LONG KePing1,2.1research Center for Optical Internet and Mobile Information Networks, university of Electronic Science and Technology of {2., Chengdu 611731, {2. 2.nstitute of Advanced Network Technology and New Serives (ANTS), university of Science and Technology Beijing, Beijing 100083, {2. 3research Center for Optical Internet Networks, Chongqing university of Posts and Telecommunications, Chongqing 400065, {2. 1. research Center for Optical Internet and Mobile Information Networks University of Electronic Science and Technology of China Chengdu 611731 China3. Research Center for Optical Internet Networks Chongqing University of Posts and Telecommunications Chongqing 400065 China2. Institute of Advanced Network Technology and New Serives (ANTS) University of Science and Technology Beijing Beijing 100083 China

Survivability for multi-domain optical networks is becoming a key parameter due to expanding network. In order to provide the shared-path-protected lightpath in multi-domain optical mesh networks, we propose a protection solution, called GSLSSP. A new source egress gateway selecting mechanism is adopted in this solution. For each connection request, this mechanism can enable the source node to select a better egress gateway node to the destination domain and compute one inter-domain working path near the optimal path with the cooperating of this gateway node, under scalability and domain privacy constraint of multi-domain networks. And then one intra-domain link-disjoint local segment-backup path for each working-segment path is computed out in each single-domain passed by the working path. Simulation evaluation shows that the proposed scheme can provide 100% protection ability for multiple failures. Besides, it is effective in multi-domain path protection with more efficient resource utilization, lower blocking probabilities and less inter-domain cost than other schemes.

关键词： survivability optical mesh networks multi-domains multiple failures segment-shared protection

efficient reconstruction of non-simple curves

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Journal of Zhejiang university-Science C(Computers and Electronics) 2011年第7期12卷 523-532页

作者： Yuan-di ZHAO 1,Jun-jie CAO 1,2.Zhi-xun SU 1,Zhi-yang LI 1 (1 School of Mathematical Sciences,Dalian university of Technology,Dalian 11602.,china) (2.State Key Laboratory of Structural Analysis for Industrial Equipment,Department of {2. Mechanics,Dalian university of Technology,Dalian 11602.,china) School of Mathematical Sciences Dalian University of Technology State Key Laboratory of Structural Analysis for Industrial Equipment Department of Engineering Mechanics Dalian University of Technology

We present a novel algorithm to reconstruct curves with self-intersections and multiple parts from unorganized strip-shaped points,which may have different local shape scales and sampling *** first extract an initial curve,a graph composed of polylines,to model the different structures of the *** a least-squares optimization is used to improve the geometric *** initial curve is extracted in three steps:anisotropic farthest point sampling with an adaptable sphere,graph construction followed by non-linear region identification,and edge *** algorithm produces faithful results for points sampled from non-simple curves without pre-segmenting *** on many simulated and real data demonstrate the efficiency of our method,and more faithful curves are reconstructed compared to other existing methods.

关键词： Reverse engineering Strip-shaped points Curve reconstruction Anisotropic adaptive sampling

Development of Chinese characterization factors for land use in life cycle impact assessment

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Science china(Technological Sciences) 2010年第6期53卷 1483-1488页

作者： LIU Yu,NIE ZuoRen,SUN BoXue,WANG ZhiHong & GONG XianZheng School of Materials Science and engineering,Beijing university of Technology,Beijing 10012.,{2. 1. School of Materials Science and engineering Beijing University of Technology Beijing 100124 China

A model with Chinese characterization factors for quantifying the damages to environment by land use in terms of the change in net primary productivity (NPP) of ecosystem was developed in the framework of life cycle assessment (LCA).In this method,the forms of land utilization were divided into two aspects involving long-term use of land (e.g.,for arable farming),namely "land occupation",and the change of land properties (e.g.,from agricultural area to urban area),namely "land transformation".Furthermore,the land use elementary flows (occupation and transformation) and parameters were linked to the impact indicators,and the characterization formulas of the two forms of land utilization were derived respectively according to the ecological ***,based on this method,the characterization factors of both land occupation and land transformation were calculated using Chinese empirical information on NPP,which can be incorporated into LCA framework and applied to Chinese LCA case study to fill up the important gap in life cycle impact assessment (LCIA) of land use.

关键词： life cycle assessment land use net primary productivity

CHEBYSHEV FINITE SPECTRAL METHOD FOR 2.D EXTENDED BOUSSINESQ EQUATIONS

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Journal of Hydrodynamics 2011年第1期23卷 1-11页

作者： LI Yok-sheung ZHAN Jie-min, SU Wei Department of Civil and Structural engineering The Hong Kong Polytechnic University Hong Kong China Department of Applied Mechanics and engineering Sun Yat-sen University Guangzhou 510275 China

In this article,an accurate Chebyshev finite spectral method for the 2.D extended Boussinesq equations is *** method combines the advantages of both the finite difference and spectral *** Adams-Bashforth predictor and the fourth-order Adams-Moulton corrector are adopted for the numerical solution of the governing differential *** efficient wave absorption strategy is also proposed to effectively absorb waves at outgoing wave boundaries and reflected waves from the interior of the computational domain due to barriers and bottom slopes at the incident wave boundary to avoid contamination of the specified incident wave *** proposed method is verified by a case where experimental data are available for comparison for both regular and irregular *** case is wave diffraction over a shoal reported by Vincent and *** results agree very well with the corresponding experimental data.

关键词： Chebyshev polynomial finite spectral method irregular waves

research on common issues for relationship between mechanism degree of freedom,driving link and executive link

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Science china(Technological Sciences) 2009年第4期52卷 966-974页

作者： WANG AiLun College of Mechanical & Electrical engineering, Central South university, Changsha 410083, {2. Key Laboratory of Modern Complex Equipment Design and Extreme Manufacturing, Ministry of Education, Changsha 410083, {2. 1. College of Mechanical & Electrical engineering Central South University Changsha 410083 China 2. Key Laboratory of Modern Complex Equipment Design and Extreme Manufacturing Ministry of Education Changsha 410083 China

During engineering practice and theoretical research, the mechanism degree of freedom is sometimes unequal to the number of the driving link, which is unable to be explained according to the classic theory of the mechanism degree of freedom. To solve this problem, the duality description for operating laws of mechanism is introduced based on the concepts of duality. The Junction-Structure Equation is established for the port descriptions of general ideal mechanism and the functional description for the mechanism degree of freedom is described by {2. of bond graph theory. The force-transfer de- gree of freedom, i.e. the antithesis concept of movement-transfer degree of freedom, is introduced and defined based on the analysis of energy transfer as well as the analysis of signal causality. By utiliza- tion of structural description, functional description and duality description for the equation of degree of freedom, the relationship between the movement-transfer degree of freedom and force-transfer de- gree of freedom is further explored and analyzed. Thus, the relationship between the mechanism de- gree of freedom upon the driving link and the executive link is described generally. Finally, some typical relationships between the mechanism degree of freedom, the driving link and the executive link are analyzed.

关键词： duality bond graph Junction-Structure Equation driving link executive link degree of freedom

A Feedback Scheme for Fountain Codes Based Transport Protocol in Space Communications

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china Communications 2015年第8期12卷 62-72页

作者： XING Yanling GE Ning Tsinghua national Laboratory for Information Science and Technology Department of Electronic engineering Tsinghua University Aerospace Communications and Terminal Application Technologies engineering Laboratory in Shenzhen

This paper proposed a practical- feedback scheme for fountain codes based transportprotocol in space communications. In the proposed scheme, the sender is signaled by two types of acknowledgment （ACK） *** decoding, packet loss probability isestimated on the receiver side and encapsulated intoa soft ACKand sent to the *** decoding,decoding results are encapsulated into hard ACKsandsent to the sender. There are two contributionsin the proposed scheme： 1. Empl layer calculation instead layer statistics to estimate oying physical of application the packet loss probability of space channel, which can improvethe accuracy and practicality. 2. A cascade overhead-failure probability relationship between the sender and the receiver has been analyzed to help determine the exact numberof packetsneeded byfountain *** show that for space communications,compared with the existing space transport protocols, fountain codes based transport protoeolwith the proposed schemecan not only ensure transmission reliability, but also greatly improvelink utilization.

关键词： fountain code feedback spacecommunication packet loss probabilityestimation transport protocol

Phase equilibrium calculation of multi-component gas separation of supersonic separator

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Science china(Technological Sciences) 2010年第3期53卷 435-443页

作者： BAO LingLing1, LIU ZhongLiang1, LIU HengWei1, JIANG WenMing1, ZHANG Ming1 & ZHANG Jian2.1 Education Ministry Key Lab of Enhanced Heat Transfer & Energy Conversation, College of Environmental and Energy engineering, Beijing university of Technology, Beijing 10012., {2. 2.Shengli engineering & research Institute, Shengli Oil Field Ltd, SINOPEC, Dongying 2.702., {2. 1. Education Ministry Key Lab of Enhanced Heat Transfer & Energy Conversation College of Environmental and Energy Engineering Beijing University of Technology Beijing 100124 China2. Shengli Engineering & Research Institute Shengli Oil Field Ltd SINOPEC Dongying 257026 China

A mathematical model for phase equilibrium prediction of multi-component gas separation process inside a supersonic separator is established and an efficient numerical solution method is designed. The model and the numerical method are then used to predict the phase equilibrium characteristics and the separation performance of a field test natural gas supersonic purification separator. The predicted results are generally in good agreement with the field test measurements, which proves that the phase equilibrium model and the solution method are both reliable and accurate, and can be used for the prediction of the vapor and liquid phase equilibrium and the separation performance and the configuration optimization of supersonic separator.

关键词： supersonic separator BWRS equation vapor-liquid separation phase equilibrium

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Cellulose conversion to polyols on supported Ru catalysts in aqueous basic solution

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Science china Chemistry 2010年第7期53卷 1476-1480页

作者： DENG TianYin,SUN JiYing & LIU HaiChao Beijing national Laboratory for Molecular Sciences,State Key Laboratory for Structural Chemistry of Stable and Unstable Species Green Chemistry Center,College of Chemistry and Molecular engineering,Peking {2.,Beijing 100871,china 1. Beijing national Laboratory for Molecular Sciences State Key Laboratory for Structural Chemistry of Stable and Unstable Species Peking University Beijing 100871 China2. Green Chemistry Center College of Chemistry and Molecular Engineering Peking University Beijing 100871 China

It is of great significance and challenge to achieve direct conversion of cellulose to specific polyols,e.g.,ethylene glycol and propylene *** such selective conversion,a novel one-pot approach was studied by combination of alkaline hydrolysis and hydrogenation on supported Ru catalysts.A wide range of bases including solid bases,e.g.,Ca(OH)2.and La2.3,and phosphate buffers were examined in the cellulose reaction in water,and the cellulose conversions and polyol products depended largely on the basicity or pH values in the aqueous *** glycol,1,2.propanediol,and especially 1,2.5-pentanetriol were obtained with selectivities of 15%,14% and 2.%,respectively,at 38% cellulose conversion at pH 8 in phosphate buffer *** preliminary results provide potentials for efficient conversion of cellulose to targeted polyols by using the advantages of bases.

关键词： cellulose polyols Ru catalysts solid bases aqueous basic solutions

EXPERIMENT ON THE CHARACTERISTICS OF 3-D VORTEX RING BEHIND A FLEXIBLE OSCILLATING CAUDAL FIN

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Journal of Hydrodynamics 2010年第3期22卷 393-401页

作者： WANG Zhi-dong LAO Yi-jia LI Li-jun CONG Wen-chao School of Naval Architecture and Ocean engineering Jiangsu University of Science and Technology Zhenjiang 212003 China Technology research Economy Development Institute B eijing 10081 China School of Naval Architecture and Ocean engineering Jiangsu University of Science and Technology Zhenjiang 212003 China

A test for the wake vortex of a flexible oscillating caudal fin is carried out with Digital Particle Image Velocimetry （DPIV）, and the variation of vortex distance and the vorticity in the range of oscillating frequency from 0.704 Hz to 1.17 Hz are analyzed. It is found that with the increase of the oscillating frequency, the vortex distance decreases and the peak of the vorticity increases, When the Strouhal number is smaller than 0.49, a larger thrust component is obtained. The distribution of the velocity circulation and the vortex distance in the different spanwise section of the caudal fin are given, and then the dimension of the vortex ring is determined. The radius of the vortex ring is 79.3 mm and the average velocity circulation is 2.152.9 mm2.s at the oscillating frequency of 0.835 Hz. The model of 3-D vortex ring chain of flexible oscillating caudal fin is constructed based on the information of wake vortex field. Finally, an effective analysis method is provided for establishing the relationship of oscillating parameters for the caudal fin and the wake structure and the intrinsic mechanism of efficient fish swimming is investigated.

关键词： Digital Particle Image Velocimetry (DPIV) flexible caudal fin flow field vortex ring