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A hybrid method for inverse cavity scattering problem for shape

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Applied mathematics(A Journal of Chinese Universities) 2010年第2期25卷 127-136页

作者： LIU Juan MA Fu-ming School of mathematics, {2. University, changchun 130012. china. School of mathematics Jilin University Changchun China

In this paper, we give a hybrid method to numerically solve the inverse open cavity scattering problem for cavity shape, given the scattered solution on the opening of the cavity. This method is a hybrid between an iterative method and an integral equations method for solving the Cauchy problem. The idea of this hybrid method is simple, the operation is easy, and the computation cost is small. Numerical experiments show the feasibility of this method, even for cases with noise.

关键词： Open cavity Cauchy problem Helmholtz equation integral equations system method iterativehybrid method.

Simulating the Folding Pathway of RNA Secondary Structure Using the Modified Ant Colony Algorithm

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Journal of Bionic Engineering 2010年第4期7卷 382-389页

作者： Jun Yu~(1,2.,Changhai Zhang~(1,2.,Yuanning Liu~(1,2.,Xin Li~(1,2. 1.College of Computer Science and Technology,jilin University,changchun {2.P.R.china 2.Key Laboratory of Symbolic Computation and Knowledge Engineering (Ministry of Education,china) jilin University,changchun {2.P.R.china [a] College of Computer Science Technology Jilin University Changchun 130012 P. R. China [b] Key Laboratory of Symbolic Computation Knowledge Engineering (Ministry of Education China) Jilin University Changchun 130012 P. R. China

A new method for simulating the folding pathway of RNA secondary structure using the modified ant colony algorithmis *** a given RNA sequence,the set of all possible stems is obtained and the energy of each stem iscalculated and stored at the initial ***,a more realistic formula is used to compute the energy ofmulti-branch loop in the following *** a folding pathway is simulated,including such processes as constructionof the heuristic information,the rule of initializing the pheromone,the mechanism of choosing the initial andnext stem and the strategy of updating the pheromone between two different *** by testing RNA sequences withknown secondary structures from the public databases,we analyze the experimental data to select appropriate values *** measure indexes show that our procedure is more consistent with phylogenetically proven structures thansoftware RNAstructure sometimes and more effective than the standard Genetic Algorithm.

关键词： RNA secondary structure folding pathway ant colony algorithm

A software cascading faults model

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Science china(Information Sciences) 2011年第11期54卷 2454-2458页

作者： LIU YanHeng 1,2.LIU XueLian 3 & WANG Jian 1,2.1 Key Laboratory of Symbolic Computation and Knowledge Engineering of Ministry of Education,jilin University,changchun {2.china 2.College of Computer Science and Technology,jilin University,changchun {2.china 3 College of Software,jilin University,changchun {2.china 1. Key Laboratory of Symbolic Computation and Knowledge Engineering of Ministry of Education Jilin University Changchun 130012 China2. College of Computer Science and Technology Jilin University Changchun 130012 China3. College of Software Jilin University Changchun 130012 China

Functions and call relations are extracted into nodes and edges,respectively,by which a novel topological model is *** directional edges and the corresponding weight values express the call relations and tightness *** introducing two concepts of function fault-tolerant capability and software fault intensity and by designing a allocation rule on fault-tolerant capability,a cascading fault model is built to explore fault propagation *** on practical software networks show that a weak fault intensity,a small number of initial faults,and a strong fault-tolerant capability can slow down the spreading *** functions with more call relations and more closer tightness contribute more to the stability of the whole system.

关键词： software fault tolerant cascading faults fault-tolerant capability fault intensity

The restricted EM algorithm under linear inequalities in a linear model with missing data

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Science china mathematics 2005年第6期48卷 819-828页

作者： ZHENG Shurong, SHI Ningzhong & GUO Jianhua School of mathematics and Statistics, Northeast Normal University, {2. 13002., china Institute of mathematics, jilin University, changchun 130012. china 1. School of mathematics and Statistics Northeast Normal University 130024 Changchun China 2. Institute of mathematics Jilin University 130012 Changchun China

This paper discusses the maximum likelihood estimate of β under linear inequalities A0β≥ a in a linear model with missing data, proposes the restricted EM algo rithm and proves the convergence.

关键词： EM algorithm, linear model, maximum likelihood estimate, missing data.

Experimental Study on Thermal Conventional Spinning of Ti-6Al-4V Alloy Complex Shape Shell

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稀有金属材料与工程 2011年第S3期40卷 78-81页

作者： Xu Hengqiu1,2. Li Mingzhe1, Zhang Rui2. Wang Dali2. Hou Fengyan2. Li Linlin2. Fan Guisen2. Shen Yujing2.1 jilin University, changchun 13002., {2. 2.changchun Institute of Equipment Technology, changchun 130012. china jilin Univ Roll Forging Res Inst Changchun 130025 Peoples R China changchun Inst Equipment Technol Changchun 130012 Peoples R China

In this paper, the process of thermal conventional spinning of Ti-6Al-4V alloy complex shape shell is studied by experiment. Billet for Ti-6Al-4V alloy board is headed in the spinning process for multi-pass conventional spinning forming. With two spinning mandrel, the first is conventional spinning pre-forming and the second is conventional end forming, vacuum heat treatment after each spinning forming. As results, the mandrel preheating temperature impacts the spinning and the appropriate temperature range plays an important role in the process of spinning. With supplemental heating means and infrared thermometer measurement ensure a stable temperature. Multi-passing thermal spinning Ti-6Al-4V alloy thins the billet thickness, using the feature obtaining the wanting complex shape shell of thick bottom and thin mouth. The spinning track, the number of spinning pass, feed rate affect the billet thinning. During thermal spinning process Ti-6Al-4V alloy rebound severe. The size reduction and feed have impact on the rebound. By modifying the spinning parameters and the mandrel repair to ensure the dimensional accuracy of workpiece. Spinning workpiece has fine grain and high strength.

关键词： Ti-6Al-4V alloy thermal spinning conventional spinning spinning temperature experimental study

The rate of convergence of the Lax-Oleinik semigroup-degenerate fixed point case

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Science china mathematics 2011年第3期54卷 545-554页

作者： WANG KaiZhi1,2.& YAN Jun1 1School of Mathematical Sciences and Key Lab of mathematics for Nonlinear Science, Fudan University, Shanghai 2.0433, {2. 2.chool of mathematics, jilin University, changchun 130012. china 1. School of Mathematical Sciences and Key Lab of mathematics for Nonlinear Science Fudan University Shanghai 200433 China2. School of Mathematics Jilin University Changchun 130012 China

For the standard Lagrangian in classical mechanics, which is defined as the kinetic energy of the system minus its potential energy, we study the rate of convergence of the corresponding Lax-Oleinik semigroup. Under the assumption that the unique global minimum point of the Lagrangian is a degenerate fixed point, we provide an upper bound estimate of the rate of convergence of the semigroup.

关键词： Hamiltonian system weak KAM theorem Lax-Oleinik semigroup

Mitochondrial DNA analysis of ancient Sampula population in Xinjiang

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Progress in Natural Science:Materials International 2007年第8期17卷 927-933页

作者： Xie Chengzhi~(1,2. Li Chunxiang~2.Cui Yinqiu~(1,2. Cai Dawei~(1,2. Wang Haijing~2.Zhu Hong~1 Zhou Hui~(1,2.*) (1.Research Center for Chinese Frontier Archaeology,jilin University,changchun {2.china 2.College of Life Science,jilin University,changchun 13002.,china) [a]Research Center for Chinese Frontier Archaeology Jilin University Changchun China [b]College of Life Science Jilin University Changchun China

The archaeological site of Sampula cemetery was located about 14 km to the southwest of the Luo County in Xinjiang Khotan,china,belonging to the ancient Yutian kingdom.14C analysis showed that this cemetery was used from 2.7 *** 2.3 A.D. Ancient DNA was analyzed by 364 bp of the mitochondrial DNA hypervariable region I （mtDNA HVR-I）,and by six restriction fragment length polymorphism （RFLP） sites of mtDNA coding *** successfully extracted and sequenced intact stretches of maternally inher- ited mtDNA from 13 out of 16 ancient Sampula *** analysis of mtDNA haplogroup distribution showed that the ancient Sampula was a complex population with both European and Asian *** joining network of U3 sub-haplogroup and multi-dimen- sional scaling analysis all showed that the ancient Sampula had maternal relationship with Ossetian and Iranian.

关键词： ancient DNA mitochondrial DNA Sampula ancient populations

LARGE TIME BEHAVIOR OF SOLUTIONS TO NEWTONIAN FILTRATION EQUATIONS WITH SOURCES

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Acta Mathematica Scientia 2010年第3期30卷 968-974页

作者：王路生尹景学王泽佳 Department of mathematics Jilin University Department of mathematics South China Normal University

This article is concerned with large time behavior of solutions to the Neumann or Dirichlet problem for a class of Newtonian filtration equations ｜x｜λ＋Эt^-Эu=div（｜x｜^k∨u^m）＋｜x｜λ＋ku^p with 0 〈 m 〈 1,p 〉 1,λ≥0, k ∈ R. An interesting phenomenon is that there exist two thresholds k∞ and kl for the exponent k, such that the critical Fujita exponent pc for p exists and is finite if k E （k∞, k1）, otherwise, pc is infinite or does not exist.

关键词： Newtonian filtration equation critical exponent exterior problem Thresh -old

A scheme for the RCP pattern of the nano-structure

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Communications in Nonlinear Science and Numerical Simulation 2001年第4期6卷 201-204页

作者： Guangwu YAN, Hongxue QU and Bing YAN Department of mathematics, jilin University,{2. Institute of Atomic and Molecular Physics, jilin University. changchun 13002., china Department of mathematics Juin University Changchun 130012 China Inst. of Atom. and Molecular Physics Jilin University Changchun 130023 China

A new scheme for the Random-Continuous-Pile (RCP) pattern is proposed to simulate a two-dimensional structure The RCP pattern is plotted.

关键词： RCP pattern. Maxwell distribution balls-filling