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china Communications 2016年第8期13卷 177-183页

作者： Zeheng Yang Yongan Guo School of Computer Science and Engineering University of Electronic Science and Technology of China(UESTC) college of telecommunications and Information Engineering Nanjing University of Posts and Telecommunications

Network virtualization is known as a promising technology to tackle the ossification of current Internet and will play an important role in the future network area. Virtual network embedding(VNE) is a key issue in network virtualization. VNE is NP-hard and former VNE algorithms are mostly heuristic in the *** exact algorithms have been developed in recent years. However, the constraints of exact VNE are only node capacity and link *** on these, this paper presents an exact VNE algorithm, ILP-LC, which is based on Integer Linear Programming(ILP), for embedding virtual network request with location constraints. This novel algorithm is aiming at mapping virtual network request(VNR) successfully as many as possible and consuming less substrate *** topology of each VNR is randomly generated by Waxman model. Simulation results show that the proposed ILP-LC algorithm outperforms the typical heuristic algorithms in terms of the VNR acceptance ratio, at least 15%.

关键词： network virtualization virtual network embedding exact VNE algorithm integer linear Programming location constraint VNR acceptance ratio

Influence of stacking fault energy on formation of long period stacking ordered structures in Mg-Zn-Y-Zr alloys

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Progress in Natural Science:Materials International 2011年第6期21卷 485-490页

作者： Fu-sheng PAN~(1,2.,Su-qin LUO~1,Ai-tao TANG~(1,2.,Jian PENG~(1,2.,Yun LU~3 1.college of Materials Science and Engineering,chongqing {2.,chongqing 400044,china 2.National Engineering Research Center for Magnesium Alloys,chongqing {2.,chongqing 400044,china 3.Faculty of Engineering,Chiba {2.,Chiba 2.3-852.,Japan [a] college of Materials Science and Engineering Chongqing University Chongqing 400044 China [b] National Engineering Research Center for Magnesium Alloys Chongqing University Chongqing 400044 China [c] Faculty of Engineering Chiba University Chiba 263-8522 Japan

The influence of alloying elements on the stacking fault energy（SFE） of Mg-Y-Zn-Zr alloys was calculated by using first-principles,and the microstructure of as-cast Mg-1.05Y-0.79Zn-0.07Zr（mole fraction,%） alloy prepared by conventional casting was investigated by SEM,TEM and *** block-like long period stacking ordered（LPSO） phase,the lamellar LPSO phase and stacking faults were observed simultaneously and the lamellar LPSO structure and stacking faults were both formed on （0001）α-Mghabit plane and grown or extended along[01 1 0]α-*** calculation results by the first-principles showed that the addition of Y can sharply decrease the stacking fault energy of the Mg-Zn-Y-Zr alloy,while Zn slightly increases the stacking fault energy of the *** influence of stacking fault energy on the formation of LPSO was *** shows that LPSO may nucleate directly through stacking faults and the lower stacking fault energy was in favor of formation of LPSO.

关键词： magnesium alloy Mg-Zn-Y-Zr long period stacking ordered(LPSO) structures stacking fault energy(SFE) firstprinciples calculation

Study on the E-commerce Ordering Platform of CKD/IKD

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武汉理工大学学报 2006年第S2期28卷 490-492页

作者： YIN Xiaoqing~1 LIU Wei~2.1.college of Mechanical Engineering,chongqing {2.,chongqing 400044,china 2.college of Economics Business Administration,chongqing {2.,chongqing 400044,china college of Mechanical Engineering Chongqing UniversityChongqing 400044China college of Economics Business Administration Chongqing UniversityChongqing 400044China

CKD/IKD is a new technology management method which should be used instead of commerce mode of *** the international trade,as to the products with fast update,complex structure,mass variety,complicated sales states and multi- mode configuration,when they are exported to enterprises without independent technology of products design from the OEM suppli- ers in the form of CKD/*** all-around intellectualized management of CKD/IKD customization,purchase and supply will be realized by transforming automatically between CKD/IKD orders and parts orders in ERP systems through KD virtual collabo- rative center,combining the e-commerce sales system,ERP,SCM,CRM,PDM and export management system.

关键词： CKD/IKD e-commerce virtual collaborative center

Secure network coding in the presence of eavesdroppers

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Science china(Information Sciences) 2010年第3期53卷 648-658页

作者： LUO MingXing1,2.3, YANG YiXian1,2.3, WANG LiCheng1,2.3 & NIU XinXin1,2.3 1Information Security Center, State Key Laboratory of Networking and Switching Technology, Beijing university of posts and {2., Beijing 100876, china 2.ey Laboratory of Network and Information Attack and Defence Technology of MOE, Beijing university of posts and {2., Beijing 100876, china 3National Engineering Laboratory for Disaster Backup and Recovery, Beijing university of posts and {2., Beijing 100876, china 1. Information Security Center State Key Laboratory of Networking and Switching Technology Beijing University of Posts and Telecommunications Beijing 100876 China2. Key Laboratory of Network and Information Attack and Defence Technology of MOE Beijing University of Posts and Telecommunications Beijing 100876 China3. National Engineering Laboratory for Disaster Backup and Recovery Beijing University of Posts and Telecommunications Beijing 100876 China

Our concern, in the paper, is to construct information-theoretic secure network coding in the presence of eavesdroppers. Based on the generalized attack model and all-or-nothing transformation, the security of network coding in the generalized combination network can be characterized by the network capacity and the min-cut bound of wiretapping set from the source. Furthermore, it can be extended to any directed acyclic networks with single source. Compared with the traditional results, we construct information-theoretic secure network coding without additional encryptions and giving up any capacity.

关键词： all-or-nothing transformation secure network coding eavesdropping

Applying flexible molecular docking to simulate protein retention behavior in hydrophobic interaction chromatography

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Science china Chemistry 2007年第5期50卷 675-682页

作者： ZHOU Peng1, TIAN FeiFei1 & LI ZhiLiang1,2.1 college of Chemistry and Chemical Engineering, chongqing {2., chongqing 400044, china 2.State Key Laboratory of Chemo/Biosensing and Chemometrics, Changsha 410082. china college of Chemistry and Chemical Engineering Chongqing UniversityChongqing400044China State Key Laboratory of Chemo/Biosensing and Chemometrics Changsha 410082China

Interaction between proteins and stationary phase in hydrophobic interaction chromatography (HIC) is differentiated into two thermodynamic processes involving direct nonbonding/conformation interac- tion and surface hydrophobic effect of proteins, hence quantitatively giving rise to a binary linear rela- tion between HIC retention time (RT) at concentrated salting liquid and ligand-protein binding free en- ergy. Then, possible binding manners for 2. proteins of known crystal structures with hydrophobic ligands are simulated and analyzed via ICM flexible molecular docking and genetic algorithm, with re- sults greatly consistent with experimental values. By investigation, it is confirmed local hydrophobic effects of proteins and nonbinding/conformation interaction between ligand and protein both notably influence HIC chromatogram retention behaviors, mainly focusing on exposed portions on the protein surface.

关键词： hydrophobic interaction chromatography, flexible molecular docking, genetic algorithm, protein, salting-in factor

A study of interaction between surface water and groundwater using environmental isotope in Huaisha River basin

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Science china Earth Sciences 2006年第12期49卷 1299-1310页

作者： SONG Xianfang1, LIU Xiangchao1, 2. XIA Jun1, YU Jingjie1 & TANG Changyuan1, 3 1. Key Laboratory of Water Cycle and Related Land Surface Processes, Institute of Geographical Sciences and Natural Re- sources Research, Chinese Academy of Sciences, Beijing 100101, china 2. college of River and Ocean, {2. Jiaotong university, {2. 400074, china 3. Chiba university, Chiba 2.3-852., Japan 1. Key Laboratory of Water Cycle and Related Land Surface Processes Institut of Geographical Sciences and Natural Resources Research Chinese Academy of Sciences Beijing 100101 China 2. college of River and Ocean Chongqing Jiaotong University Chongqing 400074 China 3. Chiba university Chiba 263-8522 Japan

The surface water and groundwater are important components of water cycle, and the interaction between surface water and groundwater is the important part in water cycle research. As the effective tracers in water cycle research, environmental isotope and hydrochemistry can reveal the interrelationships between surface water and groundwater effectively. The study area is the Huaisha River basin, which is located in Huairou district, Beijing. The field surveying and sampling for spring, river and well water were finished in 2.02.and 2.03. The hydrogen and oxygen isotopes and water quality were measured at the laboratory. The spatial characteristics in isotope and evolution of water quality along river lines at the different area were analyzed. The altitude effect of oxygen isotope in springs was revealed, and then using this equation, theory foundation for deducing recharge source of spring was estimated. By applying the mass balance method, the annual mean groundwater recharge rate at the catchment was estimated. Based on the groundwater recharge analysis, combining the hydrogeological condition analysis, and comparing the rainfall-runoff coefficients from the 1960s to 1990s in the Huaisha River basin and those in the Chaobai River basin, part of the runoff in the Huaisha River basin is recharged outside of this basin, in other words, this basin is an un-enclosed basin. On the basis of synthetically analyses, combining the compositions of hydrogen and oxygen isotopes and hydrochemistry, geomorphology, geology, and watershed systems characteristics, the relative contributions between surface water and groundwater flow at the different areas at the catchments were evaluated, and the interaction between surface water and groundwater was re- vealed lastly.

关键词： environmental isotope,hydrochemistry,surface water,groundwater,interaction.

Effect of Ca addition on the as-cast microstructure and creep properties of Mg-5Zn-5Sn magnesium alloy

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Rare Metals 2009年第6期28卷 576-581页

作者： YANG Mingbo CHENG Liang SHEN Jia PAN Fusheng Materials Science and Engineering college Chongqing University of Technology Chongqing 400050 China Materials Science and Engineering college Chongqing University Chongqing 400030 China

The effect of Ca addition on the as-cast micmstructure and creep properties of Mg-5Zn-5Sn magnesium alloy was investigated. The results indicate that adding 1.0 wt.% Ca to Mg-5Zn-5Sn alloy can effectively refine the as-cast microstructure of the alloy, and the CaMgSn phase with high thermal stability is formed in the alloy. In addition, adding 1.0 wt.% Ca to Mg-5Zn-5Sn alloy can also improve the creep properties of the alloy. After adding 1.0 wt.% Ca to Mg-5Zn-5Sn alloy, the second creep rate of the alloy at 150℃ and 50 MPa for 100 h decreases from 4.67 ×10^-8 to 1.43 × 10^-8 s^-1. The strengthening mechanism is mainly attributed to the microstructural refinement and the formation of CaMgSn phase.

关键词： magnesium alloys Ca addition creep properties microstructure

A novel multi-relay cross-layer cooperative communication strategy based on Jackson queuing model

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Science china(Information Sciences) 2010年第4期53卷 842-853页

作者： XU XiaoRong1,2. & ZHENG BaoYu1 1Institute of Signal Processing and Transmission, Nanjing university of posts and {2., Nanjing 2.0003, china 2.4} of Telecommunication Engineering, Hangzhou Dianzi university, Hangzhou 310018, china Institute of Signal Processing and Transmission Nanjing University of Posts and Telecommunications Nanjing China college of Telecommunication Engineering Hangzhou Dianzi University Hangzhou China

A novel multi-relay cooperative communication strategy based on Jackson queuing model is pro-posed, which is implemented via a cross-layer design between the physical (PHY) layer and the medium access control (MAC) layer. In the PHY layer, we focus mainly on system outage performance by analyzing in detail the relationship between the SNR threshold and the outage probabilities. While in the MAC layer, system model is treated as a Jackson queuing network, and the queue discipline for each node is assumed to be GI/M/1 model. System throughput and delay performance for the proposed strategy are also illustrated. Simulation results of the proposed cross-layer scheme are presented to validate our theoretical derivations. It is revealed that, the number of cooperative nodes influences system outage performance at high spectral efficiency regimes in the PHY layer while the proposed strategy provides a better throughput and delay performance than conventional schemes in the MAC layer.

关键词： multi-relay cooperative communication cross-layer design Jackson queuing model outage prob- abilities GI/M/1 model system throughput delay performance

An Initiative Learning Algorithm Based on System Uncertainty

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The Journal of china Universities of posts and {2. 2005年第1期12卷 53-59页

作者： ZHAO Jun~(1,2.1.Institute of Computer Science & Technology, chongqing university of {2. & telecommunications, chongqing 400065,P.R.china 2.Faculty of Engineering, Science & Built Environment, London South Bank university, SE1 0AA, London, United Kingdom Institute of Computer Science & Technology Chongqing University of Posts & Telecommunications 重庆 400065

Initiative-learning algorithms are characterized by and hence advantageousfor their independence of prior domain knowledge. Usually, their induced results could moreobjectively express the potential characteristics and patterns of information ***-learning processes can be effectively conducted by system uncertainty, becauseuncertainty is an intrinsic common feature of and also an essential link between information systemsand their induced results. Obviously, the effectiveness of such initiative-learning framework isheavily dependent on the accuracy of system uncertainty measurements. Herein, a more reasonablemethod for measuring system uncertainty is developed based on rough set theory and the conception ofinformation entropy; then a new algorithm is developed on the bases of the new system uncertaintymeasurement and the Skowron's algorithm for mining prepositional default decision rules. Theproposed algorithm is typically initiative-learning. It is well adaptable to system uncertainty. Asshown by simulation experiments, its comprehensive performances are much better than those ofcongeneric algorithms.

关键词： initiative-learning rough set system uncertainty factor system certaintyfactor system uncertainty degree

AN APPROACH TO IMPROVING THE TEACHING OF LISTENING

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Chinese Journal of Applied Linguistics 1999年第4期22卷 36-40页

作者： Lei Fang posts and telecommunications of {2. university

With more and more importance being attached to communicative competence,both teachers andlearners have become aware of how essential listening as a language skill is for ***,traditional listening classroom seems to have failed to help learners become effectiveand successful listeners both in and out of the *** learners have associated listeningcourses with pain and boredom and often complain that they benefit little from listening *** explains to some extent why many learners’ listening ability stagnates and remains at ele-mentary level although their other skills like reading,writing even speaking are advancing *** article aims to have a close look at the problems confronted by teachers in the traditionallistening classroom and,in the meantime,tries to give a brief introduction to an approach to im-proving the teaching of listening by incorporating pre-listening,while-listening and post-listeninginto an integrated listening class.

关键词： AN APPROACH TO IMPROVING THE TEACHING OF LISTENING