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Normal scalar curvature and a pinching theorem in S^m×R and H^m×R

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Science China mathematics 2011年第9期54卷 1977-1984页

作者： CHEN Qun 1,2.& CUI Qing 3,1,1 school of mathematics and Statistics,Wuhan {2.,Wuhan 430079,China 2.International Center for Theoretical Physics,Trieste 34100,Italy 3.school of mathematics,southwest jiaotong university,chengdu 61003.,China school of mathematics and Statistics Wuhan University Wuhan China International Center for Theoretical Physics Trieste Italy school of mathematics Southwest Jiaotong University Chengdu China

We obtain an inequality in Sm×R and Hm×R which is similar to DDVV *** an application,we show that a minimal submanifold in H m×R with nonnegative scalar curvature must be a surface of the type γ×R,where γ is a g... 详细信息

关键词： product spaces DDVV conjecture pinching theorem

Semantic theory of finite lattice-valued propositional logic

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Science China(Information Sciences) 2010年第10期53卷 2022-2031页

作者： PAN XiaoDong 1,2.& XU Yang 2.1 school of Maths, southwest jiaotong university, {2., China 2.Intelligent Control Development Center, southwest jiaotong university, {2., China 1. school of Maths Southwest Jiaotong University Chengdu 610031 China2. Intelligent Control Development Center Southwest Jiaotong University Chengdu 610031 China

Based on the methodology of Pavelka’s fuzzy propositional logic, in this paper, by combining L-fuzzy set and classical two-value propositional logic theory, a kind of graded semantic theory in lattice-valued propositional logic based on finite lattice implication algebras is established. The notions of L-tautology and L-contradiction are introduced, and several theorems about the relations among different kinds of L-tautologies are given. From the viewpoint of uncertainty reasoning, the notion of satisfiability with certain level for a set of formulas is also defined. On this basis, the semantic consequence operation concerning a set of formulas is proposed, and the properties of semantic consequence operation and the consistency of fuzzy information are discussed.

关键词： lattice-valued propositional logic semantic theory L-tautology consistency lattice implication algebra

STATISTICAL EVALUATION OF CRITICAL INCLUSION FACTOR FOR SECONDARY RECRYSTALLIZATON IN 3%Si STEEL Lecturer,Department of Materials Engineering,southwestern jiaotong {2.,chengdu 61003.,China

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Acta Metallurgica Sinica(English Letters) 1990年第5期3卷 327-331页

作者： LI Shuchen southwestern jiaotong {2.,chengdu,ChinaCHEN Mengzhe KE Jun {2. of Science and Technology Beijing,Beijing,China

On the basis of statistical data of MnS in the conventional 3% Si steel sheeets after various annealing processes,the critical inclusion factor has been evaluated to be 2. mm^(-1).The inhi- bition of MnS to grain grow... 详细信息

关键词： 3%Si steel secondary recrystallization inclusion factor

A new real-time eye tracking based on nonlinear unscented Kalman filter for monitoring driver fatigue

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控制理论与应用（英文版） 2010年第2期8卷 181-188页

作者： Zutao ZHANG 1 , 2., Jiashu ZHANG 2.(1.school of Mechanical Engineering, southwest jiaotong university, {2. Sichuan 61003., China 2.Sichuan Key Lab of Signal and Information Processing, southwest jiaotong university, {2. Sichuan 61003., China) school of Mechanical Engineering Southwest Jiaotong University Chengdu Sichuan China Sichuan Key Lab of Signal and Information Processing Southwest Jiaotong University Chengdu Sichuan China

A new scheme for driver fatigue detection is presented, which is based on the nonlinear unscented Kalman filter and eye tracking. Assuming a probability distribution than to approximate an arbitrary nonlinear function or transformation, eye nonlinear tracking can be achieved using an unscented transformation (UT), which adopts a set of deterministic sigma points to match the posterior probability density function of the eye movement. Driver fatigue can be detected using the percentage of eye closure (PERCLOS) framework in a realistic driving condition after the eye nonlinear tracking. This system was tested adequately in realistic driving environments with subjects of different genders, with/without glasses, in day/night driving, being commercial/noncommercial drivers, in continuous driving time, and under different road conditions. The last experimental results show that the proposed method not only improves the robustness for nonlinear eye tracking, but also can provide more accurate estimation than the traditional Kalman filter.

关键词： Eye tracking Unscented Kalman filter (UKF) Fatigue detection PERCLOS

CMC surfaces in the hyperbolic 3-space

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Chinese Science Bulletin 1998年第7期43卷 547-550页

作者： YU Zuhuan 1, 2.and LI Zhenqi 1, 3 1. Institute of mathematics, Fudan university, Shanghai 2.0433, China 2. Department of mathematics,Sichuan Union university, chengdu 610064, China 3. Department of mathematics, Nanchang university, Nanchang 33 nstitute of Mathemalics Fudan University Shanghai China Department of mathematics Sichuan Union University Chengdu China Department of mathematics Nanchang University Nanchang China

CMC-H surfaces satisfying H≥1 are studied. It is proved that these surfaces possess a natural representation which is a generalization of the Bryant’s result.

关键词： hyperbolic space CMC surface Weierstrass representation.

Design of a 400 N and 12.mm Mechanical Air Gap High Temperature Superconducting Linear Synchronous Motor

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稀有金属材料与工程 2011年第S3期40卷 319-321页

作者： Yen Fei1,2.3, Li Jing1,2.3, Zheng Shijun1,2.3, Jiang Donghui1,2.3, Liu Lu1,2.3, Liu Wei1,2.3, Ma Guangtong1,2.3, Wang Jiasu1,3, Wang Suyu1,3 1 Applied Superconductivity Laboratory, southwest jiaotong university, chengdu 61003., China 2.State Key Laboratory of Traction Power, southwest jiaotong university, chengdu 61003., China 3 National Laboratory for Rail Transit, chengdu 61003., China SW jiaotong Univ Appl Superconduct Lab Chengdu 610031 Peoples R China SW jiaotong Univ State Key Lab Tract Power Chengdu 610031 Peoples R China Natl Lab Rail Transit Chengdu 610031 Peoples R China

The static thrust output on a superconducting coated conductor coil at different excitation and alternating current suspended above a three phase alternating current long-stator comprised of copper coils is presented. Excitation current up to 45 A was applied through the superconducting coil acting as the excitation system of the superconducting linear synchronous motor (SLSM), alternating current up to 9 A was applied to the armature and magnetic air gaps of 10 and 15 mm were investigated for four different cases; coreless, with an iron core or yoke and both a core and yoke. By scaling up and converting the studied superconducting single pancake racetrack coil into a double pancake coil and connecting four of such coils in series, an SLSM prototype capable of generating 400 N of thrust output and 1 kW of power output with a 12.mm mechanical air gap operating at 77 K is proposed.

关键词： high temperature superconductivity linear synchronous motor long stator motor superconducting coil force measurements

Analysis of the Effects of Slope Geometry on the Dynamic Response of a Near-field Mountain from the Wenchuan Earthquake

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Journal of Mountain Science 2010年第4期7卷 353-360页

作者： XIAO Shiguo FENG Wenkai ZHANG Jianjing Department of Geoteehnical Engineering Southwest Jiaotong University Chengdu 610031 China State Key Laboratory of Geohazard Prevention and Geoenvironment Protection Chengdu University of Technology Chengdu 610059 China Department of C-eoteehnical Engineering Southwest Jiaotong University Chengdu 610031 China

Fourier spectra and acceleration response spectra of near-field acceleration records of the 2.08 Wenchuan Earthquake have been *** fundamental frequencies(or predominant periods) were ***,the natural frequencies of a range of slopes with different geometric characteristics,such as height,slope ratio,and pattern,were *** seismic responses of the slopes were compared,and the variability of seismic response with the above geometric elements was *** show that if slope height increases,and provided that other conditions are unchanged,the natural frequency of the first mode of a doublesurface slope will change as a power ***,natural frequencies will diminish(based on a parabolic function) as the slope angle becomes *** the surface pattern and the number of surfaces on a slope can have a great impact on the seismic response of the ***,within a certain range of slope heights or angles,either height or angle will also greatly influence the variability of the seismic *** results of this research will be helpful to understanding seismic dynamic response features and explaining the ways that slope stability can be affected by earthquakes.

关键词： Wenchuan Earthquake Slope Geometric features Dynamic response Naturalfrequency

Relaxed delay-dependent exponential stability condition for a class of neural networks with polytopic uncertainties and distributed delays

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控制理论与应用（英文版） 2011年第2期9卷 302-306页

作者： Jianwei XIA 1,2.Hongbin ZHANG 3 1.school of Automation,Southeast university,Nanjing Jiangsu 2.0096,China 2.school of mathematics Science,Liaocheng university,Liaocheng Shandong 2.2.00,China 3.school of Electronic Engineering,university of Electronic Science and Technology,chengdu Sichuan 610054,China school of Automation Southeast University Nanjing Jiangsu China school of mathematics Science Liaocheng University Liaocheng Shandong China school of Electronic Engineering University of Electronic Science and Technology Chengdu Sichuan China

The global robust exponential stability of a class of neural networks with polytopic uncertainties and distributed delays is investigated in this ***-dependent Lypaunov-Krasovskii functionals and free-weighting matrices are employed to obtain sufficient condition that guarantee the robust global exponential stability of the equilibrium point of the considered neural *** derived sufficient condition is proposed in terms of a set of relaxed linear matrix inequalities (LMIs),which can be checked easily by recently developed algorithms solving LMIs.A numerical example is given to demonstrate the effectiveness of the proposed criteria.

关键词： Neural networks Polytopic uncertainties Distributed delays Delay-dependent Global robust exponential stability

Experimental study of CT test on the failure of acrylate spray-applied waterproof layer in the groundwater environment

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Science China(Technological Sciences) 2010年第2期53卷 512-518页

作者： YANG QiXin, XU Peng & ZHENG ShangFeng 1 school of Civil Engineering, southwest jiaotong university, {2., China 1. school of Civil Engineering Southwest Jiaotong University Chengdu 610031 China

In this study the computerized tomography (CT) was first used to quantitatively analyze the failure of acrylate spray-applied waterproof membrane in the groundwater environment. The results of the CT tests show that it is feasible to use the CT to quantitatively analyze the failure of the waterproof membrane and the CT method has the advantages of speediness and accuracy that can eliminate the fussy operation process in routine tests. The main conclusions summarized from the study are as follows. First, there are two combined-indexes that can be used to decide the failure of the spray-on waterproof layer: one is that the reduced percentage of the CT number of the spray-on waterproof layer is less than 40.0% and the other is that the variance of the CT number decreases first and then increases. Second, the applicability for the spray-on waterproof layer in the groundwater environment is the SO 2.-concentration ≤ 1%, the Cl-concentration ≤ 7.5% and the pH value ≤ 12.0 of the groundwater, respectively.

关键词： spray-on waterproof layer scan CT number failure groundwater environment