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Statistical Multiscale Analysis of Transient Conduction and Radiation Heat Transfer problem in Random Inhomogeneous Porous Materials

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Computer Modeling in Engineering & Sciences 2018年第4期115卷 1-24页

作者： Yiqiang Li Liang Ma Zhiqiang Yang Xiaofei Guan Yufeng Nie Zihao Yang Department of Applied Mathematics Northwestern Polytechnical UniversityXi’an 710072China State Key Laboratory of Solidification Processing Northwestern Polytechnical UniversityXi’an 710072China School of Astronautics Harbin Institute of TechnologyHarbin 150001China School of Mathematics Sciences Tongji UniversityShanghai 200092China

This paper is devoted to the homogenization and statistical multiscale analysis of a transient heat conduction problem in random porous materials with a nonlinear radiation boundary condition.A novel statistical multiscale analysis method based on the two-scale asymptotic expansion is *** the statistical multiscale formulations,a unified linear homogenization procedure is established and the second-order correctors are introduced for modeling the nonlinear radiative heat transfer in random perforations,which are our main ***,a numerical algorithm based on the statistical multiscale method is given in *** results prove the accuracy and efficiency of our method for multiscale simulation of transient nonlinear conduction and radiation heat transfer problem in random porous materials.

关键词： Statistical multiscale analysis method transient heat conduction problem nonlinear radiation boundary condition random porous materials

Optimized design of collector topology for offshore wind farm based on ant colony optimization with multiple travelling salesman problem

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Journal of Modern Power Systems and Clean Energy 2018年第6期6卷 1181-1192页

作者： Ramu SRIKAKULAPU Vinatha U Department of Electrical and Electronics Engineering National Institute of Technology Karnataka

A layout of the offshore wind farm(OSWF)plays a vital role in its capital cost of installation. One of the major contributions in the installation cost is electrical collector system(ECS). ECS includes: submarine cables,number of wind turbines(WTs), offshore platforms etc. By considering the above mentioned problem having an optimized design of OSWF provides the better feasibility in terms of economic considerations. This paper explains the methodology for optimized designing of ECS. The proposed methodology is based on combined elitist ant colony optimization and multiple travelling salesman *** objective is to minimize the length of submarine cable connected between WTs and to minimize the wake loss in the wind farm in order to reduce the cost of cable and cable power loss. The methodology is applied on North Hoyle and Horns Rev OSWFs connected with 30 and 80 WTs respectively and the results are presented.

关键词： Ant colony optimization Offshore wind farm Multiple travelling salesman problem Wake effect Wake loss

SICE benchmark problem:starting speed control of SI engines

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Control Theory and Technology 2019年第2期17卷 138-147页

作者： Junichi KAKO Advanced Powertrain Planning&Management Div.Toyota Motor Corporation ShizuokaJapan

Starting the engine and quickly adjusting the engine speed to the target value after that will always be a challenge for vehicles with an internal combustion engines at development sites in the automotive *** SICE Research Committee on Advanced Powertrain Control Theory provided this task as a benchmark problem with the engine *** as control developers in the industry are provided actual engines,many of the academic experts have acquired engine models,analyzed behavior and constructed controls,and solved control *** summarize this activity by explaining the methods by many challengers that achieved the target performance.

关键词： Engine start control benchmark problem engine model

Characteristic Finite Difference Methods for Moving Boundary Value problem of Numerical Simulation of Oil Deposit

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Science China Mathematics 1994年第12期37卷 1442-1453页

作者：袁益让 Institute of Mathematics Shandong University Jinan 250100 PRC

The software for oil-gas transport and accumulation is to describe the history of oil-gas transport and accumulation in basin evolution. It is of great value in rational evaluation of prospecting and exploiting oil-gas resources. The mathematical model can be described as a coupled system of nonlinear partial differential equations with moving boundary value problem. This paper puts forward a kind of characteristic finite difference schemes, and derives from them optimal order estimates in l^2 norm for the error in the approximate solutions. The research is important both theoretically and practically for the model analysis in the field, for model numerical method and for software development.

关键词： numerical simulation of oil deposit moving boundary value problem characteristic finite difference method l2 error estimates

Two personification strategies for solving circles packing problem

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Science China(Technological Sciences) 1999年第6期42卷 595-602页

作者：黄文奇许如初 College of Computer Science Huazhong University of Science and Technology Laboratory of Computer Science Institute of Software Chinese Academy of Sciences Beijing 100080 China

Two personification strategies are presented, which yield a highly efficient and practical algorithm for solving one of the NP hard problems——circles packing problem on the basis of the quasi-physical algorithm. A very clever polynomial time complexity degree approximate algorithm for solving this problem has been reported by Dorit *** and Wolfgang Maass in J. ACM. Their algorithm is extremely thorough-going and of great theoretical significance. But, just as they pointed out, their algorithm is feasible only in conception and even for examples frequently encountered in everyday life and of small scale, it is the case more often than not that up to a million years would be needed to perform calculations with this algorithm. It is suggested toward the end of their paper that a heuristic algorithm of higher practical effectiveness should be sought out. A direct response to their suggestion is intented to provide.

关键词： packing problem NP hard heuristic algorithm personification method quasi-physical method.

Waring's problem for Pyramidal Numbers

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Science China Mathematics 1994年第3期37卷 277-283页

作者：邓越凡杨振宁 Department of Applied Mathematics The University at Stony BrookStony BrookNY 11794USA Institute of Theoretical Physics The University at Stony BrookStony BrookNY CAP 11794USAt has been proved that every positive integer is expressible as a sum of no more than eight pyramidal numbers P(m)=(m-1)m(m+1)/6.This paper reports on a computer calculation of the partition of integers from n=1 to 109 into pyramidal numbers.We find that no integer≤10°needs more than five pyramidal numbers for its partitionand only 241 of them do need five.We define J(n) as the least number of pyramidal numbers to partition nand Nk(n) as the number of positive integers l less than or equal to n for which J(l)=k.Based on our numerical results we make conjectures about the asymptotic form of Nk(n) for n→∞

It has been proved that every positive integer is expressible as a sum of no more than eight pyramidal numbers P(m)=(m-1)m(m+1)/*** paper reports on a computer calculation of the partition of integers from n=1 to 109 into pyramidal *** find that no integer≤10°needs more than five pyramidal numbers for its partition,and only 241 of them do need *** define J(n) as the least number of pyramidal numbers to partition n,and Nk(n) as the number of positive integers l less than or equal to n for which J(l)=*** on our numerical results we make conjectures about the asymptotic form of Nk(n) for

关键词： Waring’s problem parallel computing asymptotic form

Spectral analysis of nonselfadjoint Schrdinger problem with eigenparameter in the boundary condition

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Science China Mathematics 2007年第2期50卷 217-230页

作者： M.Yakit ONGUN Department of Mathematics Suleyman Demirel UniversityCunur Campus32260IspartaTurkey

In this paper we consider the nonselfadjoint (dissipative) Schrodinger boundary value problem in the limit-circle case with an eigenparameter in the boundary condition. Since the boundary conditions are nonselfadjoint, the approach is based on the use of the maximal dissipative operator, and the spectral analysis of this operator is adequate for the boundary value problem. We construct a selfadjoint dilation of the maximal dissipative operator and its incoming and outgoing spectral representations, which make it possible to determine the scattering matrix of the dilation. We construct a functional model of the maximal dissipative operator and define its characteristic function in terms of solutions of the corresponding Schrodinger equation. Theorems on the completeness of the system of eigenvectors and the associated vectors of the maximal dissipative operator and the Schrodinger boundary value problem are given.

关键词： nonselfadjoint Schrodinger problem eigenparameter in boundary condition maximal dissipative operator selfadjoint dilation functional model characteristic function completeness of the system of eigenvectors and associated vector.

Explicit construction of measure solutions of Cauchy problem for transportation equations

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Science China Mathematics 1997年第12期40卷 1287-1299页

作者：陈绍仲李杰权张同 Department of Mathematics Ningbo UniversityNingbo 315211China Institute of Applied Mathematics Chinese Academy of SciencesBeijing 100080China Institute of Mathematics Chinese Academy of SciencesBeijing 100080China

The transportation equations are a mathematical model of zero-pressure flow in gas dynamics and the adhesion particle dynamics system to explain the formation of large scale structures in the *** the help of convex hull of a potential function,the solution is explicitly constructed *** is straightforward to prove that the solution is a global measure *** Dirac delta-shocks explained as the concentration of particles may develop in the solution.

关键词： transportation equations Cauchy problem measure solution convex hull Dirac delta-shocks.

Stability of Rarefaction Wave to the 1-D Piston problem for the Pressure-Gradient Equations

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Chinese Annals of Mathematics,Series B 2019年第2期40卷 161-186页

作者： Min DING Department of Mathematics School of Science Wuhan University of Technology

The 1-D piston problem for the pressure gradient equations arising from the flux-splitting of the compressible Euler equations is considered. When the total variations of the initial data and the velocity of the piston are both sufficiently small, the author establishes the global existence of entropy solutions including a strong rarefaction wave without restriction on the strength by employing a modified wave front tracking method.

关键词： Piston problem Pressure gradient equations Rarefaction wave Wave front tracking method Interaction of waves