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Using Neural Network to Predict the Interfacial Friction and Flow Stress of Materials via Ring Compression

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Journal of Southeast university(English Edition) 1996年第1期12卷 53-60页

作者： Xu Weiliang (department of Mechanical Engineering, Southeast university, Nanjing 210018) Kamineni P. Rao(city university of hong kong, hong kong)

In this study a neural network approach is proposed to realize an automatic numerical prediction of the interfacial friction factor and the flow stress of materials. Decrease in the inner diameter and reduction in the... 详细信息

关键词： neural networks metal forming friction prediction flow stress prediction ring compression test

Nonuniform sampling delta modulation for digital audio processing

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Chinese Journal of Acoustics 1996年第4期15卷 367-374页

作者： ZHU Yuesheng(department of Radio Engineering, South china university of Technology Guangzhou 510641)LEUNG Saiwing and WONG Chiman(department of Electronic Engineering, city university of hong kong, Kowloon, hong kong)

A new digital audio processing system based on Nonuniform Sampling Delta Mod-ulation (NSDM) technique is presented in this paper. The performance of NSDM system is analysed. Theoretical analysis and experimental results have demonstrated that the perfor-manc e of NSDM system used in digital audio is better than that of conventional Linear Delta Modulation (LDM) in terms of coding efficiency, Signal to Quantization-Noise Ratio and dy-namic range.

关键词： Nonuniform sampling Delta modulation Digital audio Signal processing

Effects of Z-Pins Reinforcement on Interlaminar Mode Ⅰ Delamination

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Effects of Z-Pins Reinforcement on Interlaminar Mode Ⅰ Dela...

Regional　and　Synoptic-scale　Features　Associated　with　Inactive　Periods　of　the　Summer　Monsoon　over　South　china

第十三届国际复合材料会议

作者： hong-Yuan Liu and Yiu-Wing MaiCentre for Advanced Materials Technology (CAMT) department of Mechanical and Mechatronic Engineering university of Sydney NSW 2006 Australia meem city university of hong kong Kowloon hong kong china

＜正＞Introduction Z-pins reinforcement is a new technique which provides through-thickness bridging forces to laminated composites against interlaminar delamination. In the z-pins preforms, the rods, which are typically composites but can also be metals, are driven through the uncured laminates by a specialized ultrasonic insertion process. Compared to traditional through-thickness reinforcements, such as stitching, this process can minimize the amount of in-plane fibre damage and misalignment. Besides its advantage in manufacture, z-pins reinforcement has also been found to provide a higher resistance to delamination than any other through-thickness

关键词： z-pin reinforcement bridging force fibre pull-out mode I delamination

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Advances in Atmospheric Sciences 1997年第2期14卷 100-107页

作者： This research is supported by the Research Grants Council of the university Grants Committee of hong kong Grant 9040074. C. H. So and Johnny C. L. Chan department of Physics and Materials Science, city university of hong kong department of Physics and Materials Science City University of Hong Kong

This paper presents an observational study of the physical processes responsible for the inactive period (break) of the summer monsoon over South china (SC). The break of the monsoon is defined by using the rainfall data over hong kong Meteorological parameters provided by the European Centre for Medium-Range Weather Forecasts (ECMWF) for the period 1985-1990 are examined. Daily values of each parameter for the six years are then composited each day for the period of 5 days before to 1 day after the break. It is found that several days before the break, changes opposite to those occurred during the onset and active periods begin to take place. This suggests that a feedback mechanism is present which tends to restore the atmosphere to a more stable state. This mechanism may be initiated by the formation of convective clouds during the onset and active periods. These clouds then reduce the solar radiation to the ground, leading to a gradual drop in the temperature. This drop, together with the cooling of the atmosphere due to the large amounts of rainfall, causes the pressure over the SC region to become higher, which in turn induces a westward extension of the subtropical ridge. The decrease in temperature over SC may also shift the location of the heat source to the west, which leads to a concomitant westward shift of the convergence of the southerlies and results in less moisture-laden air reaching the SC region. The atmosphere then becomes unfavourable for heavy convection and therefore a break starts.

关键词： Inactive period Summer monsoon South china subtropical high

H_∞ controller synthesis of piecewise discrete time linear systems

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控制理论与应用（英文版） 2003年第1期1卷 28-34页

作者： Gang FENG(department of Manufacturing Engineering & Engineering Management, city university of hong kong, Tat Chee Ave. , Kowloon, hong kong) Deptarment of Manufacturing Engineering & Engineering Management City University of Hong Kong Tat Chee Ave. Kowloon Hong Kong

This paper presents an H∞ controller design method for piecewise discrete time linear systems based on a piecewise quadratic Lyapunov function. It is shown that the resulting closed loop system is globally stable with guaranteed H∞ performance and the controller can be obtained by solving a set of bilinear matrix inequalities. It has been shown that piecewise quadratic Lyapunov functions are less conservative than the global quadratic Lyapunov functions. A simulation example is also given to illustrate the advantage of the proposed approach.

关键词： Controller design Discrete time systems Bilinear matrix inequality Piecewise linear systems Piecewise Lya-punov functions

DESIGNING A HYBRID INTELLIGENT MINING SYSTEM FOR CREDIT RISK EVALUATION

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Journal of Systems Science & Complexity 2008年第4期21卷 527-539页

作者： Lean YU Shouyang WANG Fenghua WEN Kin Keung LAI Shaoyi HE Institute of Systems Science Academy of Mathematics and Systems Science Chinese Academy of Sciences Beijing 100190 China. School of Economy and Management Changsha University of Science ~ Technology Changsha 410076 China. department of Management Sciences City University of Hong Kong Tat Chee Avenue Kowloon Hong Kong. department of Information Systems and Operations Management College of Business Administration Cali fornia State University San Marcos San Marcos CA 92096-0001 USA.

In this study, a novel hybrid intelligent mining system integrating rough sets theory and support vector machines is developed to extract efficiently association rules from original information table for credit risk evaluation and analysis. In the proposed hybrid intelligent system, support vector machines are used as a tool to extract typical features and filter its noise, which are different from the previous studies where rough sets were only used as a preprocessor for support vector machines. Such an approach could reduce the information table and generate the final knowledge from the reduced information table by rough sets. Therefore, the proposed hybrid intelligent system overcomes the difficulty of extracting rules from a trained support vector machine classifier and possesses the robustness which is lacking for rough-set-based approaches. In addition, the effectiveness of the proposed hybrid intelligent system is illustrated with two real-world credit datasets.

关键词： Credit risk evaluation hybrid intelligent system rough sets support vector machine.

Some variants of SAT and their properties

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Progress in Natural Science:Materials International 2002年第10期 71-75页

作者： ZHAO Yunlei and ZHU hong(1. department of Computer Science, Fudan university, Shanghai 200433, china 2. department of Computer Science, city university of hong kong, Tat Chee Avenue, Kowloon, hong kong) department of Computer Science，Fudan university，Shanghai 200433，china department of Computer Science，city university of hong kong，Tat Chee Avenue，Kowloon，hong kong department of Computer Science，Fudan university，Shanghai 200433，china

A new model for the well-known problem, the satisfiability problem of boolean formula (SAT), is introduced. Based on this model, some variants of SAT and their properties are presented. Denote by NP the class of all languages which can be decided by a non-deterministic polynomial Turing machine and by P the class of all languages which can be decided by a deterministic polynomial-time Turing machine. This model also allows us to give another candidate for the natural problems in ((NP-NPC)-P), denoted as NPI, under the assumption P≠NP, where NPC represents NP-complete. It is proven that this candidate is not in NPC under P≠NP. While, it is indeed in NPI under some stronger but reasonable assumption, specifically, under the Exponential-Time Hypothesis (ETH) . Thus we can partially solve this long standing important open problem.

关键词： NP-complete Karp-reduction SAT ETH NPI SNP.

Heterophase junction engineering-induced Co spin-state modulation of CoSe_(2) for large-current hydrogen evolution reaction

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Rare Metals 2024年第6期43卷 2660-2670页

作者： Bao-Chai Xu Ya-Ping Miao Min-Qin Mao Dong-Lian Li Song Xie Wei-hong Jin Shu Xiao Jing Wen Zaenab Abd-Allah Zhi-Tian Liu Xiang Peng Paul K.Chu Hubei Key Laboratory of Plasma Chemistry and Advanced Materials School of Materials Science and EngineeringWuhan Institute of TechnologyWuhan 430205China School of Textile Science and Engineering Xi'an Polytechnic UniversityXi'an 710048China Institute of Advanced Wear and Corrosion Resistant and Functional Materials Jinan UniversityGuangzhou 510632China Institute of Safety Science and Engineering South China University of TechnologyGuangzhou 510641China department of Engineering Manchester Metropolitan UniversityManchester M156BHUK department of Physics Department of Materials Science and Engineeringand Department of Biomedical EngineeringCity University of Hong KongHong Kong 999077China

Efficient electrocatalysts are vital to large-current hydrogen production in commercial water splitting for green energy ***,a novel heterophase engineering strategy is described to produce polymorphic CoSe_(2)*** composition of the electrocatalysts consisting of both cubic CoSe_(2)(c-CoSe_(2))and orthorhombic CoSe_(2)(o-CoSe_(2))phases can be controlled *** results demonstrate that junction-induced spin-state modulation of Co atoms enhances the adsorption of intermediates and accelerates charge transfer resulting in superior large-current hydrogen evolution reaction(HER)***,the CoSe_(2)based heterophase catalyst with the optimal c-CoSe_(2)content requires an overpotential of merely 240 mV to achieve 1,000 mA·cm^(-2)as well as a Tafel slope of 50.4 mV·dec^(-1).Furthermore,the electrocatalyst can maintain a large current density of 1,500 mA·cm^(-2)for over 320 h without *** results reveal the advantages and potential of heterophase junction engineering pertaining to design and fabrication of low-cost transition metal catalysts for large-current water splitting.

关键词： Heterophase junction Spin-state Hydrogen evolution reaction Large current electrochemical hydrogen production Water splitting

Study of MMLV RT-Binding with DNA using Surface Plasmon Resonance Biosensor

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Acta Biochimica et Biophysica Sinica 2005年第9期37卷 634-642页

作者： Lei WU~1 Ming-Hui HUANG~2 Jian-Long ZHAO~(1*) Meng-Su YANG~~(1,2*) 1 Shanghai Institute of Microsystem and Information Technology,Chinese Academy of Sciences,Shanghai 200050,china 2 department of Bioloy and Chemistry,city university of hong kong,hong kong,china ShanghaiInstituteofMicrosystemandInformationTechnology ChineseAcademyofSciencesShanghai200050China

Surface plasmon resonance biosensor technique was used to study the binding of Moloneymurine leukemia virus reverse transcriptase without RNase H domain （MMLV RT-） with DNA in the ab-sence and in the presence of *** DNA substrates,including single-stranded DNA （ssDNA）,DNA template-primer （T-P） duplex and gapped DNA,were immobilized on the biosensor chip surface usingstreptavidin-biotin,and MMLV RT--DNA binding kinetics were analyzed by different *** RT-could bind with ssDNA and the binding was involved in conformation *** RT- binding DNA T-Pduplex and gapped DNA could be analyzed using the simple 1:1 Langmuir *** lack of RNase Hdomain reduced the affinity between MMLV RT- and T-P *** effects of RT inhibitors,includingefavirenz,nevirapine and quercetin,on the interaction between MMLV RT- and gapped DNA were analyzedaccording to recovered kinetics *** slightly interfered with the binding between RT andDNA and the affinity constant in the presence of the inhibitor (KA=1.21×106 M-1) was lower than in theabsence of the inhibitor (KA=4.61×106 M-1).Nevirapine induced relatively tight binding between RT andDNA and the affinity constant in the presence of the inhibitor (KA=1.47×107 M-1) was approximately threefolds higher than without nevirapine,mainly due to rapid association and slow ***,aflavonoid originating from plant which has previously shown strong inhibition of the activity of *** to have minimal effect on the RT-DNA binding.

关键词： surface plasmon resonance biosensor reverse transcriptase kinetics inhibitor