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Discovering admissible Web services with uncertain QoS

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Frontiers of Computer Science 2015年第2期9卷 265-279页

作者： Xiaodong fu Kun YUE Li LIU Ping ZOU yong FENG Yunnan Provincial Key Laboratory of Computer Technology Application Faculty of Information Engineering and Automation Kunming University of Science and Technology Kunming 650500 China School of Information Science and Engineering Yunnan University Kunming 650091 China Faculty of Management and Economics Kunming University of Science and Technology Kunming 650093 China

Open and dynamic environments lead to inher- ent uncertainty of Web service QoS （Quality of Service）, and the QoS-aware service selection problem can be looked upon as a decision problem under uncertainty. We use an empiri- cal distribution function to describe the uncertainty of scores obtained from historical transactions. We then propose an approach to discovering the admissible set of services in- cluding alternative services that are not dominated by any other alternatives according to the expected utility criterion. Stochastic dominance （SD） rules are used to compare two services with uncertain scores regardless of the distribution form of their uncertain scores. By using the properties of SD rules, an algorithm is developed to reduce the number of SD tests, by which the admissible services can be reported pro- gressively. We prove that the proposed algorithm can be run on partitioned or incremental alternative services. Moreover, we achieve some useful theoretical conclusions for correct pruning of unnecessary calculations and comparisons in each SD test, by which the efficiency of the SD tests can be im- proved. We make a comprehensive experimental study using real datasets to evaluate the effectiveness, efficiency, and scal- ability of the proposed algorithm.

关键词： Web services uncertain QoS partial preference,empirical distribution function stochastic dominance admis-sible set

Adaptive rate control on wireless transcoder

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Journal of Systems Engineering and Electronics 2007年第3期18卷 633-640页

作者： Chen Xudong Zhu Qingxin Liao yong fu Qingyun Xiong Guangze School of Computer Science and Engineering Univ. of Electronic Science and Technology Chengdu 610054 P. R. China

To guarantee the real-time transmission of a video stream, based on the stochastic optimal control method, a frame layer adaptive rate control algorithm for the wireless transcoder is proposed, which is capable of dynamically determining the transcoder＇s objective bit rate, according to the bandwidth variation of the wireless channel and the buffer occupancy. Then the transient performance, steady performance, and computational complexity of the algorithm are analyzed. Finally, the experiment results demonstrate that the algorithm can improve the synthetic performance of rate control through the compromise between the end-to-end delay and the playout quality.

关键词： streaming media rate control transcoder wireless local area network H.264/AVC.

Measurement of the thermal transport properties of dielectric thin films using the micro-Raman method

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Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2009年第1期10卷 7-16页

作者： Shuo HUANG Xiao-dong RUAN Xin fu Hua-yong YANG State Key Laboratory of Fluid Power Transmission and Control Zhejiang University Hangzhou 31002 7 China

The micro-Raman method is a non-contact and non-destructive method for thermal conductivity *** reduce the measurement error induced by the poor fit of the basic equation of the original micro-Raman method,we developed a new basic equation for the heat source of a Gaussian laser *** on the new basic equation,an analytical heat transfer model has been built to extend the original micro-Raman method to thin films with submicrometer-or nanometer-scale ***-periments were performed to measure the thermal conductivity of dielectric thin films with submicrometer-or nanometer-scale *** thermal resistance of the interface between dielectric thin films and their silicon substrate was also *** obtained thermal conductivity of silicon dioxide film is 1.23W/(m.K),and the interface thermal resistance between silicon dioxide film and substrate is 2.35×10-8m2.K/*** thermal conductivity and interface thermal resistance of silicon nitride film are 1.07W/(m.K)and 3.69×10-8m2.K/W,*** experimental results are consistent with reported data.

关键词： Thermal conductivity Dielectric thin films Submicrometer- or nanometer-scale Porous silicon Thermal effect micro-systems (TEMS)

Non-linear Dynamics of Inlet Film Thickness during Unsteady Rolling Process

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Chinese Journal of Mechanical Engineering 2016年第3期29卷 522-530页

作者： fu Kuo ZANG yong GAO Zhiying QIN Qin WU Diping School of Mechanical Engineering University of Science and Technology Beijing

The inlet film thickness directly affects film and stress distribution of rolling interfaces. Unsteady factors, such as unsteady back tension, may disturb the inlet film thickness. However, the current models of unsteady inlet film thickness lack unsteady disturbance factors and do not take surface topography into consideration. In this paper, based on the hydrodynamic analysis of inlet zone an unsteady rolling film model which concerns the direction of surface topography is built up. Considering the small fluctuation of inlet angle, absolute reduction, reduction ratio, inlet strip thickness and roll radius as the input variables and the fluctuation of inlet film thickness as the output variable, the non-linear relationship between the input and output is discussed. The discussion results show that there is 180° phase difference between the inlet film thickness and the input variables, such as the fluctuant absolute reduction, the fluctuant reduction ratio and non-uniform inlet strip thickness, but there is no phase difference between unsteady roll radius and the output. The inlet angle, the steady roll radius and the direction of surface topography have significant influence on the fluctuant amplitude of unsteady inlet film thickness. This study proposes an analysis method for unsteady inlet film thickness which takes surface topography and new disturbance factors into consideration.

关键词： cold rolling lubricant film inlet zone surface topography unsteady non-linear

Effect of Surface Mechanical Attrition Treatment on Tribological Behavior of the AZ31 Alloy

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Journal of Materials Science & Technology 2016年第12期32卷 1245-1252页

作者： Shuangwu Xia yong Liu Dongming fu Bin Jin Jian Lu Key Laboratory of Near Net Forming of Jiangxi Province Nanchang University Department of Mechanical and Biomedical Engineering City University of Hong Kong Centre for Advanced Structural Materials Shenzhen Research InstituteCity University of Hong Kong

By surface mechanical attrition treatment（SMAT）,a gradient nano structure（GNS） from the surface to center was generated in the AZ31 alloy *** tribological behavior of AZ31 alloy with GNS was systematically investigated by using dry sliding tests,a 3D surface profile-meter and a scanning electron microscope equipped with an energy-dispersive *** experimental results indicate that the Mg alloy with GNS exhibits better wear resistance comparing to the as-received sample,which is associated to the alteration of wear mechanism at different sliding *** Mg alloy with GNS presents the wear mechanism of the abrasive wear at 0.05 m/s and the oxidative wear at 0.5 m/s,***,the GNS can effectively promote the reaction between the oxygen and worn surface,which leads to a compact oxidation layer at 0.5 m/*** effect of oxidation layer on the wear resistance of the Mg alloy was also discussed.

关键词： Magnesium alloy Surface mechanical attrition treatment Wear mechanism Oxidation layer

Active generalized predictive control of turbine tip clearance for aero-engines

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Chinese Journal of Aeronautics 2013年第5期26卷 1147-1155页

作者： Peng Kai Fan Ding Yang Fan fu Qiang Li yong School of Power and Energy Northwestern Polytechnical University Aeronautics and Astronautics Engineering College Air Force Engineering University School of Flight Technology Civil Aviation Flight University of China

Active control of turbine blade tip clearance continues to be a concern in design and control of gas turbines. Ever increasing demands for improved efficiency and higher operating temperatures require more stringent tolerances on turbine tip clearance. In this paper, a turbine tip clearance control apparatus and a model of turbine tip clearance are proposed; an implicit active generalized predictive control （GPC）, with auto-regressive （AR） error modification and fuzzy adjustment on control horizon, is presented, as well as a quantitative analysis method of robust per- turbation radius of the system. The active clearance control （ACC） of aero-engine turbine tip clear- ance is evaluated in a lapse-rate take-off transient, along with the comparative and quantitative analysis of the stability and robustness of the active tip clearance control system. The results show that the resultant active tip clearance control system with the improved GPC has favorable steadystate and dynamic performance and benefits of increased efficiency, reduced specific fuel consump- tion, and additional service life.

关键词： Active clearance control(ACC) Aero-engine Aircraft Generalized prcdictivc control (GPC) Global convergence Robust perturbation radius Turbine tip clearance

Transcriptomic Analysis of the Highly Heterotic Maize Hybrid Zhengdan 958 and Its Parents During Spikelet and Floscule Differentiation

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Journal of Integrative Agriculture 2012年第11期11卷 1783-1793页

作者： LI Zhi-yong ZHANG Ti-fu WANG Shou-cai National Maize Improvement Center/Maize Breeding Engineering Center Ministry of Education~Key Laboratory of Crop Genomicsand Genetic Improvement Ministry of Agriculture~College of Agriculture and Biotechnology China Agricultural University Beijing100193 P.R.China

Heterosis plays an important role in crop production and plant evolution. Although heterosis has been widely exploited by plant breeders, the underlying molecular mechanisms are not well understood. We analyzed gene expression of the highly heterotic maize hybrid Zhengdan 958 and its parents, Zheng 58 and Chang 7-2 during spikelet and floscule differentiation using the GeneChip Maize Genome Array. Pairwise comparison among Zhengdan 958 and its parents at the two stages of immature ear development identfied 1 089 and 1 352 differentially expressed genes. Gene ontology （GO） functional analysis showed that these genes participate in many functional categories, and those encoding response to stress and transcription factor may play important roles in heterosis. Pathway analysis showed that the differentially expressed genes are involved in various metabolic processes, and those participating in lipid metabolism, signal transduction, transport, and catabolism may contribute to heterosis. A non-additive expression pattern was prevalent in genes that were differentially expressed between the hybrid and its parents during both spikelet and floscule differentiation. Because genes that are differentially expressed in a hybrid and its parents could underlie heterosis, nonadditive expression patterns might contribute to the manifestation of heterosis.

关键词： maize heterosis microarray gene expression Zhengdan 958 spikelet floscule

Impacts of climate change on the potential forest productivity based on a climate-driven biophysical model in northeastern China

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Journal of Forestry Research 2020年第6期31卷 2273-2286页

作者： Wen-Qiang Gao Xiang-Dong Lei Li-yong fu Institute of Forest Resource Information Techniques Chinese Academy of ForestryKey Laboratory of Forest Management and Growth ModellingState Forestry and Grassland AdministrationBeijing 100091People’s Republic of China

Climate warming is expected to influence forest growth,composition and ***,accurately estimating and predicting forest biomass,potential productivity or forest growth is still a challenge for forest managers dealing with land-use at the stand to regional *** the present study,we predicted the potential productivity(PP)of forest under current and future climate scenarios(RCP2.6,RCP4.5,RCP6.0 and RCP8.5)in Jilin province,northeastern China by using Paterson’s Climate Vegetation and Productivity(CVP)index *** PP was validated by comparing it with the mean and maximum net primary production calculated from light energy utilization(GLM_PEM).Our results indicated that using the CVP index model is partially valid for predicting the potential forest productivity in northeastern *** exhibited obvious spatial heterogeneity varying from 4.6 to 8.9 m3 ha-1 year-1 with an increasing tendency from northwest to southeast driven by the precipitation across the *** number of vegetation-active months,precipitation and insolation coefficient were identified as the primary factors affecting PP,but no significant relationship was found for warmest temperature or temperature *** future climate scenarios,PP across the Jilin Province is expected to increase from 1.38%(RCP2.6 in 2050)to 15.30%(RCP8.5 in 2070),especially in the eastern Songnen Plain(SE)for the RCP8.5 scenarios.

关键词： Climate vegetation and productivity index Potential productivity Climate change

Solvent‑aided phase separation in hydrogel towards significantly enhanced mechanoresponsive strength

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Acta Mechanica Sinica 2021年第5期37卷 757-766,I0001页

作者： Haibao Lu Ziyu Xing Mingji Chen Kai Yu yong Qing fu National Key Laboratory of Science and Technology on Advanced Composites in Special Environments Harbin Institute of TechnologyHarbin 150080China Institute of Advanced Structure Technology Beijing Institute of TechnologyBeijing 100081China Department of Mechanical Engineering University of Colorado DenverDenverCO 80217USA Faculty of Engineering and Environment University of NorthumbriaNewcastle upon Tyne NE18STUK

Understanding working principles and thermodynamics behind phase separations,which have significant influences on condensed molecular structures and their performances,can inspire to design and fabricate anomalously and desirably mechanoresponsive ***,a combination of techniques from physicochemistry and mechanics has yet been established for the phase separation in *** this study,a thermodynamic model is firstly formulated to describe solvent-aided phase and microphase separations in the hydrogels,which present significantly improved mechanoresponsive ***-Huggins theory and interfacial energy equation have further been applied to model the thermodynamics of concentration-dependent and temperature-dependent phase *** intricately detailed phase map has finally been formulated to explore the working *** thermodynamic methodology of phase separations,combined with the constitutive stress-strain relationships,has a great potential to explore the working mechanisms in mechanoresponsive hydrogels.

关键词： Hydrogel Mechanoresponsive Phase separation Microphase separation