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A rate based congestion control algorithm in networks with coexisting unicast and multicast sessions

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Journal of University of Science and Technology Beijing 2003年第3期10卷 66-72页

作者： Qian Dong and Jianying XieSchool of Electronics & Information Technology, shanghai Jiaotong University, shanghai 200030, China Sch. of Electron. and Info. Technol. Shanghai Jiaotong Univ. Shanghai 200030 China

The optimal rate control problem in networks with unicast and multiratemulticast sessions is investigated. A penalty function approach is used to solve a convex programformulation of this problem, and then a heuristic rate control algorithm is derived. The algorithmis distributed, and suitable both for source-driven unicast sessions and receiver-driven multicastsessions. To obtain practical viability, the computational burden on core routers as well asend-hosts is kept very low, also is the overhead of network congestion feedback. Simulation resultsshow that the algorithm guarantees TCP (Transmission Control Protocol)-based unicast sessionscoexisting with multirate multicast sessions in a fair and friendly manner. It is also shown thatvarious fairness criteria of resource allocation could be achieved by choosing appropriate utilityfunctions, and resource-utilizing efficiencies would be likewise different.

关键词： multicast unicast congestion control rate control fairness

Static Analysis of Collision Strength of Offshore Platform

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China Ocean Engineering 1996年第1期11卷 45-54页

作者： Li Runpei Chen Weigang Gu Yongning Professor, shanghai Jiao Tong University, shanghai 200030 Assistant, shanghai Jiao Tong University, shanghai 200030 shanghai Jiao Tong University Shanghai 200030

In this paper a numerical analysis method combining FEM incemental technique with limit analysis concept is proposed for the study of the static strength of offshore platform in collision. Large deformation and plasticity are accounted for and the limit yield surface expressed by generalized stress for a tubular section is derived. The modified stiffness matrix of space beam element is formulated by Plastic Node Method. The buckling behavior of beam columns can also be taken into account. It can trace the generation of plastic hinges during loading and finally the ultimate strength of offshore platform against collision is obtained.

关键词： offshore platform collision ultimate strength Plastic Node Method

One of the origins for curved edges of polyethylene singlecrystals

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Chinese Science Bulletin 1998年第7期43卷 564-568页

作者： YAN Deyue Department of Applied Chemistry, shanghai Jiaotong University, shanghai 200030, China Department of Applied Chemistry Shanghai Jiaotong University Shanghai China

A new concept of lattice strain was developed to explain the origin of the curved edges of polyethylene (PE) single crystals. In the crystallization of PE from poor solvents, the length of critical nucleus generated is rather short. The thin lamellae are thermodynamically unstable especially at high temperature. Thereby, during the growth of PE single crystals an annealing process is going on simultaneously, which results in a reduction of thickness from the center to growing faces of lamellae. It is known that the thinner the single crystals, the bigger the unit-cell dimensions. Consequently, unit-cells in the central part of single crystals formed are somewhat smaller than those in the outer part of the same crystals. In order to fit in with the gradual enlargement of unit-cell dimensions from the center to the edges of single crystals, the lattice planes of a faster growing dominant {110} deform to be a set of parallel arcs of concentric circles. Accordingly, the edge of a slower growing subordinate {200} becomes a part of an ellipse with obvious curvature while the edge of a {110} sector remains almost straight for it is a small part of a large circumference.

关键词： PE single crystals curved lateral habit lattice strain.

Martensitic Transformation in Fe-Mn-Si Based Shape Memory Alloys

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Journal of Materials Science & Technology 1999年第2期15卷 111-116页

作者： T. Y. Hsu (XU Zuyao)(shanghai Jiao Tong University, shanghai 200030, China) shanghai Jiao Tong University Shanghai 200030 China Chinese Academy of Sciences China

The critical driving force for martensitic transformation fcc ( gamma ) yields hcp ( epsilon ) in ternary Fe-Mn-Si alloys increases with the content of Mn and decreases with that of Si. Thermodynamical prediction of M//s in ternary Fe-Mn-Si alloys was established. The fcc ( gamma ) yields hcp ( epsilon ) martensitic transformation in Fe-Mn-Si is a semi-thermoelastic and the nucleation process does not strongly depend on soft mode. Nucleation occurs directly through an overlapping of stacking fault rather than pole mechanism, and it is suggested that stacking fault energy (SFE) is the main factor controlling nucleation. Based on the phenomenological theory of martensite crystallography, a shuffle on (0001)//h//c//p plane is required when d//1//1//1 does not equal d//0//0//0//2. The derived principal strain in Bain distortion is smaller, i, e., more reasonable than the values given by Christian. Alloying elements strengthening the austenite, lowering SFE of gamma phase and reducing T//N** gamma temperature may be beneficial to shape memory effect of Fe-Mn-Si based alloys. Accordingly, Fe-Mn-Si-RE and Fe-Mn-Si-Cr-N (or Fe-Mn-Si-Ni-Cr-N) are worthy to be recommended as shape memory materials with improved shape memory effect. (Edited author abstract) 48 Refs.

关键词： Mn Martensitic Transformation in Fe-Mn-Si Based Shape Memory Alloys Fe Si

CAPACITATED LOT SIZING AND SCHEDULING PROBLEMS USING HYBRID GA/TS APPROACHES

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Chinese Journal of Mechanical Engineering 2003年第1期16卷 21-24页

作者： Yang Honghong Wu ZhimingDepartment of Automation,shanghai Jiaotong University,shanghai 200030, China Department of Automation Shanghai Jiaotong University 上海 200030

The capacitated lot sizing and scheduling problem that involves indetermining the production amounts and release dates for several items over a given planning horizonare given to meet dynamic order demand without incurring backloggings. The problem consideringovertime capacity is studied. The mathematical model is presented, and a genetic algorithm (GA)approach is developed to solve the problem. The initial solutions are generated after usingheuristic method. Capacity balancing procedure is employed to stipulate the feasibility of thesolutions. In addition, a technique based on Tabu search (TS) is inserted into the genetic algorithmdeal with the scheduled overtime and help the convergence of algorithm. Computational simulation isconducted to test the efficiency of the proposed hybrid approach, which turns out to improve boththe solution quality and execution speed.

关键词： Production planning Capacitated lot sizing Genetic algorithm Tabusearch Capacity balancing

NONLINEAR DATA RECONCILIATION METHOD BASED ON KERNEL PRINCIPAL COMPONENT ANALYSIS

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Chinese Journal of Mechanical Engineering 2003年第2期16卷 117-119页

作者： Yan Weiwu Shao HuiheDepartment of Automation,shanghai Jiaotong University,shanghai 200030, China Department of Automation Shanghai Jiaotong University Shanghai 200030 China

In the industrial process situation, principal component analysis (PCA) is ageneral method in data reconciliation. However, PCA sometime is unfeasible to nonlinear featureanalysis and limited in application to nonlinear industrial process. Kernel PCA (KPCA) is extensionof PCA and can be used for nonlinear feature analysis. A nonlinear data reconciliation method basedon KPCA is proposed. The basic idea of this method is that firstly original data are mapped to highdimensional feature space by nonlinear function, and PCA is implemented in the feature space. Thennonlinear feature analysis is implemented and data are reconstructed by using the kernel. The datareconciliation method based on KPCA is applied to ternary distillation column. Simulation resultsshow that this method can filter the noise in measurements of nonlinear process and reconciliateddata can represent the true information of nonlinear process.

关键词： principal component analysis kernel data reconciliation nonlinear

MODELLING OF P/M FORMING PROCESSES BY FEM

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中国有色金属学会会刊：英文版 1995年第3期5卷 66-70页

作者： Wei, Yuanping Ruan, Xueyu(Department of Plasticity Technology,shanghai Jiao Tong University, shanghai 200030) shanghai Jiao Tong Univ Shanghai China

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关键词： modelling P/M forming FEM yield criteria constitutive

DEADLOCK-FREE SCHEDULING METHOD BASED ON PETRI NET AND GA

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Chinese Journal of Mechanical Engineering 2003年第4期16卷 371-375页

作者： Xu Gang Wu ZhimingSchool of Automation,shanghai Jiaotong University,shanghai 200030, China School of Automation Shanghai Jiaotong University Shanghai 200030 China

An efficient algorithm for finding an optimal deadlock-free schedule in amanufacturing system with very limited buffer is presented. This algorithm is based on the effectivegenetic algorithm (GA) search method, and a formal Petri net structure is introduced to detect thetoken player assuring deadlock-free. In order to make the scheduling strategy generated by GA meetthe required constraint of deadlock-free, Petri net is involved to make the implementation of thejob scheduling in an FMS deadlock-free. The effectiveness and efficiency of the proposed approach isillustrated by using an example.

关键词： GA Petri net Deadlock-free scheduling

DETERMINATION　OF　MECHANICAL　PROPERTIES　INMICROZONE　OF　METAL　MATRIX　COMPOSTITES　BY　ULTRAMICROHARDNESS

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中国有色金属学会会刊：英文版 1996年第4期6卷 122-126页

作者： Chen Yu Zhang Guoding(State Key Lab of MMCs,shanghai Jiao Tong University,shanghai 200030) State Key Lab. of MMCs Shanghai Jiao Tong University Shanghai 200030 China

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关键词： ultramicrohardness interface metal matrix composites residual stress