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A MIXED ELECTRIC BOUNDARY VALUE PROBLEM FOR AN ANTI-PLANE PIEZOELECTRIC CRACK

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Acta Mechanica Solida Sinica 2003年第2期16卷 110-115页

作者： Huang Zhenyu Kuang Zhenbang (department of engineering Mechanics,shanghai jiaotonguniversity,shanghai 2.02.0,china) department of engineering Mechanics Shanghai Jiaotong University Shanghai 200240 China

The analytical continuation method is adopted to solve a mixed electric boundary value problem for a piezoelectric medium under anti-plane *** crack face is partly conductive and partly *** results show that the stress intensity factor is identical with the mode Ⅲ stress intensity factor independent of the conducting *** the electric field and the electric displacement are dependent on the electric boundary conditions on the crack faces and are singular not only at the crack tips but also at the junctures between the impermeable part and conducting portions.

关键词： piezoelectric medium fracture mechanics mixed boundary value problem

Forecasting of Stock Returns by Using Manifold Wavelet Support Vector Machine

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Journal of shanghai jiaotong university(science) 2010年第1期15卷 49-53页

作者：汤凌冰盛焕烨汤凌霄 department of computer science and engineering Shanghai Jiaotong University department of computer and Electronic engineering Hunan Business College School of Economics Changsha University of Science & Technology

An admissible manifold wavelet kernel is proposed to construct manifold wavelet support vector machine(MWSVM) for stock returns *** manifold wavelet kernel is obtained by incorporating manifold theory into wavelet technique in support vector machine(SVM).Since manifold wavelet function can yield features that describe of the stock time series both at various locations and at varying time granularities,the MWSVM can approximate arbitrary nonlinear functions and forecast stock returns *** applicability and validity of MWSVM for stock returns forecasting is confirmed through experiments on real-world stock data.

关键词： stock returns forecasting kernel manifold wavelet support vector machine (MWSVM)

MODELLING AND COMPUTATION OF UNSTEADY TURBULENT CAVITATION FLOWS

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Journal of Hydrodynamics 2006年第5期18卷 559-566页

作者： CHEN Ying LU Chuan-jing WU Lei department of engineering Mechanics Shanghai Jiaotong University Shanghai 200240 China

Unsteady turbulent cavitation flows in a Venturi-type section and around a NACA0012 hydrofoil were simulated by two-dimensional computations of viscous compressible turbulent flow model. The Venturi-type section flow proved numerical precision and reliability of the physical model and the code, and further the cavitation around NACA0012 foil was investigated. These flows were calculated with a code of SIMPLE-type finite volume scheme, associated with a barotropic vapor/liquid state law which strongly links density and pressure variation. To simulate turbulent flows, modified RNG k-ε model was used. Numerical results obtained in the Venturi-type flow simulated periodic shedding of sheet cavity and was compared with experiment data, and the results of the NACA0012 foil show quasi-periodic vortex cavitation phenomenon. Results obtained concerning cavity shape and unsteady behavior, void ratio, and velocity field were found in good agreement with experiment ones.

关键词： turbulent cavitation Venturi NACA0012

ANALYSIS OF PULSATILE FLOW IN THE PARALLEL-PLATE FLOW CHAMBER WITH SPATIAL SHEAR STRESS GRADIENT

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Journal of Hydrodynamics 2007年第1期19卷 113-120页

作者： QIN Kai-rong HU Xu-qu LIU Zhao-rong department of engineering Mechanics Shanghai Jiaotong University Shanghai 200240 China Institute of Biomechanics Fudan University Shanghai 200433 China

The Parallel-Plate Flow Chamber （PPFC）, of which the height is far smaller than its own length and width, is one of the main apparatus for the in-vitro study of the mechanical behavior of cultured vascular Endothelical Cells （ECs） exposed to fluid shear stress. The steady flow in different kinds of PPFC has been extensively investigated, whereas, the pulsatile flow in the PPFC has received little attention. In consideration of the characteristics of geometrical size and pulsatile flow in the PPFC, the 3-D pulsatile flow was decomposed into a 2-D pulsatile flow in the vertical plane, and an incompressible plane potential flow in the horizontal plane. A simple method was then proposed to analyze the pulsatile flow in the PPFC with spatial shear stress gradient. On the basis of the method, the pulsatile fluid shear stresses in several reported PPFCs with spatial shear stress gradients were calculated. The results were theoretically meaningful for applying the PPFCs in-vitro, to simulate the pulsatile fluid shear stress environment, to which cultured ECs were exposed.

关键词： Pulsatile flow fluid shear stress spatialshear stress gradient parallel-plate flow chamber culturedendothelial cells cell mechanics

An integrated quantum secure communication system

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science china(Information sciences) 2011年第12期54卷 2598-2611页

作者： DAI WenChao, LU Yuan, ZHU Jun & ZENG GuiHua State Key Lab of Advanced Optical Communication Systems and Networks, department of Electronic engineering shanghai jiaotong university, shanghai 2.02.0, china 1. State Key Lab of Advanced Optical Communication Systems and Networks Department of Electronic Engineering Shanghai Jiaotong University Shanghai 200240 China

In this paper, we investigate experimentally an integrated quantum secure communication system using weak coherent state. Two modules are involved in the presented system. One is used for generating the secret key which is obtained using continuous variable quantum key distribution scheme, and the other serves to encrypt and decrypt the real-time private data using a pure quantum cryptographic algorithm. The sifted key rate with reverse reconciliation is 8.6 and 3.9 kb/s in the quantum key distribution scheme under the individual attack and the collective attack, respectively. The system uses an all-fiber dual unbalance beam Mach-Zehnder interferometer, and is implemented with a 500 kb/s modulation rate over 27.2 km of optical fiber.

关键词： quantum key distribution quantum stream encryption integrated system

Optimal power allocation for cognitive relay networks: amplify-and-forward versus selection relay

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science china(Information sciences) 2011年第4期54卷 861-872页

作者： YUE WenJing 1,2,ZHENG BaoYu 1,2,MENG QingMin 1,YUE WenJie 3 & CUI JingWu 1 1 Institute of Signal Processing and Transmission,Nanjing university of Posts and Telecommunications,Nanjing 210003,china 2 department of Electronic engineering,shanghai jiaotong university,shanghai 2.02.0,china 3 Shanxi Institute of Educational science,Taiyuan 030009,china 1. Institute of Signal Processing and Transmission Nanjing University of Posts and Telecommunications Nanjing 210003 China2. Department of Electronic Engineering Shanghai Jiaotong University Shanghai 200240 China3. Shanxi Institute of Educational Science Taiyuan 030009 China

We consider a cognitive relay network which is defined by a source,a destination,and cognitive relay nodes and primary user *** this network,a source is assisted by cognitive relay nodes which allow coexisting with primary user nodes by imposing severe constraints on the transmission power so that they operate below the noise floor of primary user *** this paper,we mainly study the power allocation strategies of this system to minimize the outage probability subject to total and individual power constraints for cognitive relay nodes and subject to interference constraints for primary user nodes.A relay transmission scheme,namely amplify-and-forward (AF),is *** first present an optimal power allocation (OPA) scheme to minimize the system outage probability,based on instantaneous channel state information among the source,destination and relay nodes and mean channel gains between primary user nodes and cognitive ***,we propose a selection AF scheme (S-AF) where the single best relay is chosen to assist in the transmission and study power allocation strategy for S-AF to minimize outage *** analytical power allocation strategies have been validated through numerical *** results indicate that the AF with OPA and S-AF with OPA have significantly better outage behavior and average throughput than AF and S-AF schemes *** also find that S-AF with OPA achieves a higher throughput,and hence lower outage probability than AF with OPA.

关键词： cognitive radio (CR) relay networks power allocation outage probability

Design of multiple anti-windup loops for multiple activations

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science china(Information sciences) 2012年第9期55卷 1925-1934页

作者： WU XiongJun 1,2 & LIN Zongli 3,1 1 department of Automation,shanghai Jiao Tong university,and Key Laboratory of System Control and Information Processing,Ministry of Education of china,shanghai 2.02.0,china 2 No.802 Institute of shanghai Academy of Space Flight Technology,the Eighth Academy of china Aerospace science and Technology Corporation,shanghai 200090,china 3 Charles L.Brown department of Electrical and computer engineering,university of Virginia,P.O.Box 400743,Charlottesville,VA 22904-4743,USA 1. department of Automation Shanghai Jiao Tong University and Key Laboratory of System Control and Information Processing Ministry of Education of China Shanghai 200240 China2. No. 802 Institute of Shanghai Academy of Space Flight Technology the Eighth Academy of China Aerospace Science and Technology Corporation Shanghai 200090 China3. Charles L. Brown Department of Electrical and Computer Engineering University of Virginia P.O. Box 400743 Charlottesville VA 22904-4743 USA

This paper considers anti-windup design for linear systems subject to actuator *** anti-windup gains are designed for activations immediately at the occurrence actuator saturation,after the saturation has reached a certain level and in anticipation of the occurrence of saturation,*** design is based on the minimization of L 2 gain from the disturbance to the controlled output of the resulting closed-loop *** anti-windup scheme involves a single anti-windup loop for immediate activation.A recent innovation is to design a single anti-windup loop for delayed or anticipatory activation,as well as to design two anti-windup gains,one for immediate activation and one for delayed *** design of three anti-windup gains for three different activations is shown through simulation to lead to significant further performance improvement over the previous activation schemes.

关键词： actuator saturation anti-windup anticipatory activation delayed activation L 2 gain nonlinear control

Computational neuroscience in china

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science china(Life sciences) 2010年第3期53卷 385-397页

作者： WU Si1 & LIANG PeiJi2 1Institute of Neuroscience,shanghai Institutes for Biological sciences,State Key Laboratory of Neurobiology,Chinese Academy of sciences,shanghai 200031,china 2department of Biomedical engineering,shanghai jiaotong university,shanghai 2.02.0,china 1. Institute of Neuroscience Shanghai Institutes for Biological Sciences State Key Laboratory of Neurobiology Chinese Academy of Sciences Shanghai 200031 China2. Department of Biomedical Engineering Shanghai Jiaotong University Shanghai 200240 China

The ultimate goal of Computational Neuroscience(CNS) is to use and develop mathematical models and approaches to elucidate brain *** is a young and highly multidisciplinary *** heavily interacts with experimental neuroscience and such other research areas as artificial intelligence,robotics,computer vision,information science and machine *** paper reviews the history of CNS in china,its current status and the prospects for its future *** of CNS research in china are also presented.

关键词： computational neuroscience experimental neuroscience artificial intelligence

Wholly smoothing cutter orientations for five-axis NC machining based on cutter contact point mesh

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science china(Technological sciences) 2010年第5期53卷 1294-1303页

作者： BI QingZhen,WANG YuHan,ZHU LiMin & DING Han State Key Laboratory of Mechanical System and Vibration,School of Mechanical engineering,shanghai jiaotong university,shanghai 2.02.0,china 1. State Key Laboratory of Mechanical System and Vibration School of Mechanical Engineering Shanghai Jiaotong University Shanghai 200240 China

Cutting forces with respect to different cutter orientations are analyzed for five-axis NC machining of a ball-end cutter.A measure is then defined to quantify the effects of cutter orientation *** to the measure,a novel model and algorithm are proposed to wholly optimize cutter orientations based on a cutter contact(CC) point *** method has two *** is that the cutter orientation smoothnesses along the feed direction and pick-feed direction are both wholly *** other is that only the accessibility cones of mesh points are required to compute and the computation efficiency is *** advantages are shown by simulating the machining efficiency,the stability of feed velocities and the smoothness of cutting force.A computational example and a cutting experiment are finally given to illustrate the validity of the proposed method.

关键词： five-axis machining tool path accessibility cone cutter orientation