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A general communication performance evaluation model based on routing path decomposition

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Journal of Zhejiang university-science C(computers and Electronics) 2011年第7期12卷 561-573页

作者： Ai-lian CHENG 1,Yun PAN 1,2,Xiao-lang YAN 2,Ruo-hong HUAN 3.(1 department of information science and Electronic Engineering,Zhejiang {3.,Hangzhou 3.0027,china) (2 Institute of VLSI Design,Zhejiang {3.,Hangzhou 3.0027,china) (3.college of computer science and technology,Zhejiang {3. of technology,Hangzhou 3.0023.china) department of information science and Electronic Engineering Zhejiang University Institute of VLSI Design Zhejiang University

The network-on-chip (NoC) architecture is a main factor affecting the system performance of complicated multi-processor systems-on-chips (MPSoCs).To evaluate the effects of the NoC architectures on communication efficiency,several kinds of techniques have been developed,including various simulators and analytical *** simulators are accurate but time consuming,especially in large space explorations of diverse network configurations;in contrast,the analytical models are fast and flexible,providing alternative methods for performance *** this paper,we propose a general analytical model to esti-mate the communication performance for arbitrary NoCs with wormhole routing and virtual channel flow *** resolve the inherent dependency of successive links occupied by one packet in wormhole routing,we propose the routing path decomposition approach to generating a series of ordered link *** we use the traditional queuing system to derive the fine-grained transmission latency for each network *** to our experiments,the proposed analytical model provides a good approximation of the average packet latency to the simulation results,and estimates the network throughput precisely under various NoC configurations and ***,the analytical model runs about 10 5 times faster than the cycle-accurate NoC *** applications of the model including bottleneck detection and virtual channel allocation are also presented.

关键词： Analytical model Communication performance Network-on-chip (NoC) Queuing system Routing path decom-position Virtual channel

SYNTHESIS AND CHARACTERIZATION OF FOUR-ARMED BLOCK POLY(STYRENE-b-p-NITROPHENYL METHACRYLATE)PREPARED BY THE ATRP METHOD

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Chinese Journal of Polymer science 2002年第4期20卷 353-360页

作者： Cai-yuan Pan Lei Tao Ye Liu department of Polymer science and Engineering university of science and technology of china, Hefei 23.026 china department of Polymer science and Engineering University of Science and Technology of China Hefei 230026

A novel tetrafunctional initiator, C [CH_2O (CH_2)_3.OOCCH(Br)CH_3._4 (1), was synthesized through the reaction oftetraol with α-bromopropionyl chloride, and then was used as initiator of atom transfer radical polymerization (ATRP) in thepreparation of 4-armed polystyrene (PSt) with narrow polydispersity. The structure, molecular weight and molecular weightdistribution (MWD) of each arm were studied by ~1H-NMR and GPC data of hydrolyzed products of the 4-armed PSt. TheATRP of St using 1/CuBr/bpy as initiator system is of 'living' character based on the following evidence: narrow MWD,constant concentration of chain radical during the polymerization, control of molecular weight by the molar ratio of monomerconsumed to 1. The 4-armed poly(St-b-p-nitrophenyl methacrylate) [poly(St-b-NPMA)] was prepared by the ATRP ofNPMA using 4-armed PSt with terminal bromine as the initiator, and characterized by FT-IR, ~1H-NMR spectra and GPCcurves. The micelles with PSt as core, and PNPMA as shell were formed by dropping DMSO into a solution of 4-armedpoly(St-b-NPMA) in DMF, as proved by laser light scatter (LLS) method.

关键词： Tetrafunctional initiator Atom transfer radical polymerization 4-Armed polystyrene 4-Armed poly(styrene-b-pnitrophenyl methacrylate) Unimolecular micelles

Self-healing routing: failure,modeling and analysis

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science china(information sciences) 2011年第3期54卷 609-622页

作者： XU MingWei 1,2 , LI Qi 1,2 , YANG Yuan 1,2 , HOU MeiJia 1,2 & PAN LingTao 1,2 1 department of computer science,{3., Beijing 100084, china 2 tsinghua National Laboratory for information science and technology (TNList), Beijing 100084, china 1. department of computer science Tsinghua University Beijing 100084 China2. Tsinghua National Laboratory for Information Science and Technology (TNList) Beijing 100084 China

Network failures occur frequently, and self-healing ability of existing routing protocols cannot guarantee fast route convergence under these failures without impacting packet forwarding. During routing convergence, network routes may be incorrect and even routing black holes and loops occur, which will result in extensive packet loss and thus influence network performance. To solve this problem, several improved routing solutions have been proposed. In this paper, we propose the concept and model of self-healing routing and analyze the key problems in current intra-domain and inter-domain self-healing routing protocols after briefly reviewing the characteristics of network failures. We classify the different self-healing solutions into two categories based on their design principles: routing restoration and routing protection, and systematically analyze these different typical solutions. Finally, we discuss several key issues in self-healing routing and propose a hybrid protection and restoration based routing scheme.

关键词： failure intra-domain routing inter-domain routing self-healing routing

An architecture for mobile database management system

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Journal of university of science and technology Beijing 2002年第2期9卷 156-160页

作者： Dong Li and Yucai Feng computer School, Huazhong university of science and {3., Wuhan 43.074, china computer School Huazhong University of Science and Technology Wuhan 430074 China

In order to design a new kind of mobile database management system (DBMS)more suitable for mobile computing than the existent DBMS, the essence of database systems in mobilecomputing is analyzed. An opinion is introduced that the mobile database is a kind of dynamicdistributed database, and the concept of virtual servers to translate the clients' mobility to theservers' mobility is proposed. Based on these opinions, a kind of architecture of mobile DBMS, whichis of versatility, is presented. The architecture is composed of a virtual server and a local DBMS,the virtual server is the kernel of the architecture and its functions are described. Eventually,the server kernel of a mobile DBMS prototype is illustrated.

关键词： mobile database dynamic distributed database DBMS architecture virtual server data region

Three-Dimensional and Cross-sectional Characteristics of Normal Grain Growth Based on Monte Carlo Simulation

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International Journal of Minerals,Metallurgy and Materials 1998年第3期12卷 129-133,139页

作者： Xiaoyan Song Guoquan Liu(Material science and Engineering School, university of science and {3. Beijing, Beijing 100083. china)(department of Materials science and Engineering, Hebei university of {3., Tianjin 3.013., china) Material science and Engineering School University of Science and Technology Beijing Beijing 100083 China departments of Materials science and Engineering Hebei University of Technology Tianjin 300130 China

An appropriate Monte Carlo method was developed to simulate the three-dimensional normal grain growth more completely. Comparative investigation on the three-dimensional and the cross-sectional characteristics of normal grain growth was done. It was found that the time exponent of grain growth determined from cross-section exhibits the same rule of increasing slowly with time and approaching the theoretical value n = 0.5 of steadygrain growth as the three-dimensional (3.D) system. From change of the number of grains per unit area with timemeasured in cross-section, the state of 3.D normal grain growth may be predicted. The gtain size distribution incross-section is different from that in 3.D system and can not express the evolution characteristic of the 3.D distribution. Furthermore, there exists statistical connection between the topological parameters in cross-section and thosein three-dimensions.

关键词： Monte Carlo simulation normal grain growth three-dimension cross-section characteristics

Suppression of Phase and Amplitude Damping Decoherence in a Three-Level Atom in A-Configuration Using Bang-Bang Controls

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Communications in Theoretical Physics 2007年第7期48卷 71-74页

作者： WANG Yan-Hui LIU Xiao-Shu LONG Gui-Lu1 Key Laboratory for Atomic and Molecular Nanosciences and department of Physics,tsinghua {3.,Beijing 100084,china2 tsinghua National Laboratory for information science and technology,tsinghua {3.,Beijing 100084,china Key Laboratory for Atomic and Molecular Nanosciences and department of Physics Tsinghua University Beijing 100084 China tsinghua National Laboratory for information science and {3. Tsinghua University Beijing 100084 China

In this paper,we present decoupling bang-bang operations for the suppression of general decoherence,bothamplitude and phase damping,in a three-level system in *** give a program to design a sequence ofperiodic twinbor... 详细信息

关键词： bang-bang operation general decoherence three-level system

EFFECT OF BIAS STRESS ON NON-LINEAR INTERNAL FRICTION OF Al-Mg ALLOY

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Acta Metallurgica Sinica(English Letters) 1992年第3期5卷 166-171页

作者： TAN Qi university of science and technology of{3.,Hefei,china Univ of science and technology of China Hefei China

The influence of longitudinal and torsional bias stresses on anomalous amplitude-dependent internal friction was *** longitudinal bias stress may always weaken the anomalous amplitude-dependent effect,while the torsional one may induce different effects from differ- ent directions *** stress effect exhibits only in properly heat treated and cold worked ahoy *** anomalous amplitude-dependent internal friction peaks,P_3.P_2 and P_1, are found to be related closely to slant dislocation kink ***,the application of bias stress to internal friction would be contributed to the study on dislocation structure.

关键词： internal friction bias stress anomalous amplitude effect dislocation kink

Research into a theoretical mode of coherent structures in the wall region of a turbulent boundary layer induced by a wall local disturbance

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Progress in Natural science:Materials International 2009年第9期19卷 1119-1124页

作者： Changgen Lua,*, Qinjuan Qi b a college of Atmospheric sciences, Nanjing university of {3. science & technology, Nanjing 210044, china b college of Public Management, Nanjing university of {3. science & technology, Nanjing 210044, china [a]college of Atmospheric sciences Nanjing University of Information Science & Technology Nanjing 210044 China [b]College of Public Management Nanjing University of Information Science & Technology Nanjing 210044 China

The idea of applying direct numerical simulation (DNS), a theoretical mode of coherent structures in the wall region of a turbulent boundary layer, has been discussed in the literature. The various aspects of the formation mechanism of the coherent structures agree well with both DNS and experimental results. In addition, a close relationship has been found between the evolutional characteristics and factors such as the magnitude and structural distribution of the wall local impulse disturbance, and the amount of energy a local disturbance introduces into the wall region. Moreover, these parameters play key roles in the formation of coherent structures near the wall region of a turbulent boundary layer. Therefore, the wall local impulse disturbance provides a theoretical model for triggering the formation of coherent structures in the wall region of a turbulent boundary layer.

关键词： Turbulent boundary layer Wall region Coherent structure Local disturbance

Effect of rare earths on phase transformation in as-cast ZA27 alloy dur-ing compressive creep

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Rare Metals 2003年第4期22卷 259-264页

作者： WEIXiaowei SHENBaoluo DepamnentofAppliedPhysics UniversityofElectronicScienceandTechnologyofChinaChengdu610045China DeparlanentofMetalscience SichuanUniversityChengdu610065China

The effect of the mixed rare earths of Ce on the phase transformation in ascast ZA 27 alloy during compressive was investigated under 3. MPa and at 160 deg C by X-raydiffraction technique and SEM. The results showed that the as cast microstructure of ZA 27-RE alloyconsisted of a dendritic Al-rich alpha' surrounded by Zn-rich beta' phase, interdendritic epsilonphase and Zn-rich eta phase together with a complex Z phase which was a complex constitute compound,(RE,Cu)Al_5Zn_(16), dispersed in crystal interfaces or branch crystal interfaces and stable duringcompressive creep test at 160 deg C. The phase transformations of ZA 27-RE alloy, decomposition ofbeta' phase arid four transformation, were delayed by the addition of rare earths, also the lamellarstructure and the spheroidized structure in ZA 27-RE alloy were finer than in ZA 27 alloy duringcompressive creep test at 160 deg C at the same creep time, and the compressive creep resistance ofZA 27-RE alloy was higher than that of ZA 27 alloy.

关键词： microstructure change compressive creep rare earths ZA 27 alloy