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Neural Network Based Scheduling for Variable-Length Packets in Gigabit Router with Crossbar Switch Fabric and Input Queuing

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Wuhan university Journal of Natural Sciences 2002年第3期7卷 313-318页

作者： Li Sheng\|hong, Xue Zhi, Li Jian\|hua, Zhu Hong\|wen department of Electronic engineering, {2. Jiaotong university, {2. 2.0030, china shanghai Jiaotong university Department of Electronic Engineering Shanghai China (GRID:grid.16821.3c) (ISNI:***)

A high-speed and effective packet scheduling method is crucial to the performance of Gigabit routers. The paper studies the variable-length packet scheduling problem in Gigabit router with crossbar switch fabric and input queuing, and a scheduling method based on neural network is proposed. For the proposed method, a scheduling system structure fit for the variable-length packet case is presented first, then some rules for scheduling are given. At last, an optimal scheduling method using Hopfield neural network is proposed based on the rules. Furthermore, the paper discusses that the proposed method can be realized by hardware circuit. The simulation result shows the effectiveness of the proposed method.

关键词： Key words scheduling neural networks input queuing gigabit router

SYNERGY OF WALL SHEAR STRESS AND CIRCUMFERENTIAL STRESS IN STRAIGHT ARTERIES

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Journal of Hydrodynamics 2005年第6期17卷 752-757页

作者： QIN Kai-rong XU Zhe WU Hao JIANG Zong-lai LIU Zhao-rong Institute of Mechanobiology and Medical engineering Shanghai Jiaotong University Shanghai 200240 China department of Mechanics and engineering Science Fudan University Shanghai 200433 China Institute of Mechanobioiogy and Medical engineering Shanghai Jiaotong University Shanghai 200240China

The Wall Shear Stress （WSS） generated by blood flow and Circumferential Stress （CS） driven by blood pressure have been thought to play an important role in blood flow-dependent phenomena such as angiogenesis, vascular remodeling, and atherosgenesis. The WSS and CS in straight arteries were calculated by measuring the blood pressure, center-line velocity, wall thickness, and radius of vessels. The WSS and CS in the time domain were then decomposed into the amplitude and phase in the frequency domain. The CS amplitude to the WSS amplitude ratio （referred as stress ampli tude ratio, Zs ） and the phase difference between the CS and the WSS （referred as stress phase difference, SPA） in the fre quency domain were calculated to characterize the synergy of the CS and WSS. Numerical results demonstrated that the CS is not in phase with the WSS, a time delay in the time domain or a stress phase difference in the frequency domain between the WSS and the CS exists. Theoretical analysis demonstrated that the Zs and SPA are primarily determined by the local fac tors （blood viscosity, local inertial effects, local geometry, loeal elasticity） and the input impedance of whole downstream arterial beds. Because the arterial input impedance has been shown to reflect the physiological and pathological states of whole downstream arterial beds, the stress amplitude ratio Zs and stress phase difference SPA would be thought to be the appropriate indices to reflect the effects of states of whole downstream arterial beds on the local blood flow dependent phenomena such as angiogenesis, vascular remodeling, and atherosgenesis.

关键词： Wall Shear Stress (WSS) Circumferential Stress (CS) wall shear stress-circumferential stress synergy,angiogenesis vascular remodeling atherosgenesis

EXPERIMENTAL INVESTIGATION ON VORTEX BREAKDOWN IN SPIN-UP AND SPIN-DOWN PROCESSES VIA PIV

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Journal of Hydrodynamics 2003年第2期15卷 58-63页

作者： LiuYing-zheng KoyamaHideS. ChenHan-ping departmentofPowerMachineryengineering ShanghaiJiaotongUniversityShanghai200030China departmentofMechanicalengineering TokyoDenkiUniversityTokyo101-8457Japan

The whole field measurements of swirling flow in spin-up and spin-downprocesses via PIV are presented in the paper. Investigation of the flow patterns at H/R = 1. 50 wasexperimentally carried out for the first time in both processes. By means of symmetry analysis, itis found that the overall flow structure in the spin-up process still keep axi-symmetric to a greatextent, but deteriorated very fast in the spin-down process. The time to settle to the state of restin the spin-down process is found to be greatly shorter than the time to achieve the steady statein the spin-up process. Temporarily oscillatory vortex breakdown was discovered during the spin-upprocess, although no breakdown in the steady state at the same Reynolds number is found in preciousresearches.

关键词： vortex breakdown PIV swirling flow

A Probability Approach to Anomaly Detection with Twin Support Vector Machines

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Journal of shanghai Jiaotong university(Science) 2010年第4期15卷 385-391页

作者：聂巍何迪 department of Electronic engineering Shanghai Jiaotong University

Classification of intrusion attacks and normal network flow is a critical and challenging issue in network security study. Many intelligent intrusion detection models are proposed, but their performances and efficiencies are not satisfied to real computer networks. This paper presents a novel effective intrusion detection system based on statistic reference model and twin support vector machines （TWSVMs）. Moreover, a network flow feature selection procedure has been studied and implemented with TWSVMs. The performances of proposed system are evaluated through using the fifth international conference on knowledge discovery and data mining in 1999 （KDD＇99） data set collected at MIT＇s Lincoln Labs and the results indicate that the proposed system is more efficient and effective than conventional support vector machines （SVMs） and TWSVMs.

关键词： intrusion detection system (IDS) twin support vector machines (TWSVMs) probability

Grey Markov chain and its application in drift prediction model of FOGs

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Journal of Systems engineering and Electronics 2005年第2期16卷 388-393页

作者： Fan Chunling 1,2., Jin Zhihua1, Tian Weifeng1 & Qian Feng11. department of Information Measurement Technology and Instrument, shanghai Jiaotong {2.,shanghai 2.0030, P. R. china 2. College of Automation and Electric engineering, Qingdao {2. of Science and Technology,Qingdao 2.6042. P. R. china department of Information Measurement Technology and Instrument Shanghai Jiaotong University Shanghai 200030 P. R. China College of Automation and Electric engineering Qingdao University of Science and Technology Qingdao 266042 P. R. China

A novel grey Markov chain predictive model is discussed to reduce drift influence on the output of fiber optical gyroscopes (FOGs) and to improve FOGs' measurement precision. The proposed method possesses advantages of grey model and Markov chain. It makes good use of dynamic modeling idea of the grey model to predict general trend of original data. Then according to the trend, states are divided so that it can overcome the disadvantage of high computational cost of state transition probability matrix in Markov chain. Moreover, the presented approach expands the applied scope of the grey model and makes it be fit for prediction of random data with bigger fluctuation. The numerical results of real drift data from a certain type FOG verify the effectiveness of the proposed grey Markov chain model powerfully. The Markov chain is also investigated to provide a comparison with the grey Markov chain model. It is shown that the hybrid grey Markov chain prediction model has higher modeling precision than Markov chain itself, which prove this proposed method is very applicable and effective.

关键词： grey model Markov chain FOG drift.

Pseudo-Random Sequences Generator Based on Discrete Hyperchaotic Systems

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Journal of Systems engineering and Electronics 2003年第4期14卷 84-89页

作者： Li Changgang & Han Zhengzhi department of Automation, shanghai Jiaotong {2., shanghai 2.0030, P. R. china department of Automation Shanghai Jiaotong University Shanghai 200030 P. R. China

We first design a discrete hyperchaotic system via piece-wise linear state feedback. The states of the closed loop system are locally expanding in two directions but absolutely bounded on the whole, which implies hyperchaos. Then, we use three suchlike hyperchaotic systems with different feedback gain matrices to design a pseudo-random sequence generator (PRSG). Through a threshold function, three sub-sequences generated from the output of piecewise linear functions are changed into 0-1 sequences. Then, followed by XOR operation, an unpredictable pseudo-random sequence (PRS) is ultimately obtained. The analysis and simulation results indicate that the PRS, generated with hyperchaotic systems, has desirable statistical features.

关键词： discrete hyperchaotic system piecewise linear state feedback pseudo-random sequences.

NUMERICAL STUDY ON THE MIXING OF UNSORTED SEDIMENT PARTICLES DISCHARGED INTO A CROSS-FLOW BY MULTIPHASE PARTICLE-IN-CELL (MP-PIC) METHOD

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International Journal of Sediment Research 2007年第2期22卷 150-159页

作者： Jie GU1, Chiwai LI2. Hong YANG1 and Yong ZHAN31 department of Environmental engineering, College of Marine Science and Technology, {2. Fisheries university, 334 Jungong Road, {2. 2.0090, china2.department of civil and Structural engineering, The Hong Kong Polytechnic university, Hunghom, Kowloon, Hong Kong, china3 department of Environmental engineering, College of Urban Construction and Environment, university of {2. for Science and Technology, 516 Jungong Road, {2. 2.0093, china shanghai Fisheries Univ Coll Marine Sci & Technol Dept Environm Engn Shanghai 200090 Peoples R China Hong Kong Polytech Univ Dept Civil & Struct Engn Kowloon Hong Kong Peoples R China shanghai Univ Sci & Technol Coll Urban Construct & Environm Dept Environm Engn Shanghai 200093 Peoples R China

The mixing characteristics of dredged sediments of variable size discharged into cross-flow are studied by an Eulerian-Lagrangian method. A three-dimensional (3D) numerical model has been developed by using the modified k-ε parameterization for the turbulence in fluid phase/water and a Lagrangian method for the solid phase/sediments. In the model the wake turbulence induced by sediments has been included as additional source and sink terms in the k-ε model; and the trajectories of the sediments are tracked by the Lagrangian method in which the sediment drift velocities in cross-flow are computed by a multiphase particle-in-cell (MP-PIC) method and the diffusion process is approximated by a random walk model. The hydrodynamic behavior of dumped sediment cloud is governed by the total buoyancy on the cloud, the drag force on each particle and velocity of cross-flow. The cross-flow destroys more or less the double vortices occurred in stagnant ambience and dominates the longitudinal movement of sediment cloud. The computed results suggest satisfactory agreement by comparison with the experimental results of laboratory.

关键词： 3D numerical model Two-phase flow Eulerian-Lagrangian method Sediment particle cloud Cross-flow Multiphase particle-in-cell (MP-PIC) method

The seasonal and daily CO_2.concentration variance in karst meadow soil profile with depth in Central Guizhou, china

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Chinese Science Bulletin 1999年第S2期44卷 93-94页

作者： ZHENG Leping~(1,2., LI Tingyu~2. WAN Guojiang~2. WANG Shijie~2.and OUYANG Ziyuan~2.1. department of Environmental Science and engineering,{2., shanghai 200072, china 2. State Key Laboratory of Environmental Geochemistry, Institute of Geochemistry, Chinese Academy of Sciences, Guiyang 550002. china department of Environmental Science and engineering Shanghai University Shanghai 200072 China State Key Laboratory of Environmental Geochemistry Institute of Geochemistry Chinese Academy of Sciences Guiyang 550002 China

THE seasonal variance of soil CO2.concentration with depth in soil profile was widely studied. Few similarresearches on this topic have been done in karst area which comprises 15% global terrestrial area. In thisnote,... 详细信息

THE seasonal variance of soil CO2./sub> concentration with depth in soil profile was widely studied. Few similarresearches on this topic have been done in karst area which comprises 15% global terrestrial area. In thisnote, the research results about the seasonal and daily soil CO2./sub> concentration variance in karst area arereported. The soil gases were collected respectively by the sampling device at 2.0, 5,0, -5, -10,-15, -2., -35 and -45 cm from the land surface in meadow soil profile described by Zheng andlocated in the Hongfeng lake area in the central Guizhou Plateau which lies in the central East-Asia karstarea. Sampling time is in the morning, midday and at night in April, August and November, 1998 aswell as in January, 1999, respectively. Concentrations （volume percent） of CO2./sub> in soil gas samples

关键词： soil CO2 concentration karst area Guizhou Province.

Stable carbon isotopic composition of soil organic carbon in karst area in Central Guizhou, china

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Chinese Science Bulletin 1999年第S2期44卷 87-88页

THE stable carbon isotopic composition of soil organic carbon is a powerful tool for discussing the source ofsoil CO2.and the relationship of CO2.source and sink between soil CO2.and atmosphere CO2.and has beenwidely ... 详细信息

THE stable carbon isotopic composition of soil organic carbon is a powerful tool for discussing the source ofsoil CO2./sub> and the relationship of CO2./sub> source and sink between soil CO2./sub> and atmosphere CO2./sub> and has beenwidely studied. However, few similar researches have been done in karst area which comprises 15%global terrestrial area. Preliminary research results about the stable carbon isotopic composition of soil organic carbon in karst area are reported here. In April and August 1998, the samples were collected continuously at 5-cm intervals from 0 to -45cm depth in meadow soil profile described by Zheng and located in the Hongfong Lake area in the central Guizhou Plateau which lies in the central East-Asia karst area. CO2./sub> for δ13 C analysis was prepared

关键词： δ13C of soil organic carbon karst area Guizhou Province.