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A PCA-based method for ancestral informative markers selection in structured populations

Science china(Life Sciences) 2009年第10期52卷 972-976页

作者： ZHANG Feng1,3, ZHANG Lei1,3 & DENG Hong-Wen1,2.3 1 Key Laboratory of Biomedical Information Engineering of Ministry of Education, institute of Molecular Genetics, School of Life Science and Technology, Xi’an jiaotong {2., Xi’an 710049, china 2.institute of Bioscience and Biotechnology, School of Science, beijing jiaotong university, beijing 100044, china 3 Departments of Orthopedic Surgery and Basic Medical Science, School of Medicine, {2. of Missouri-Kansas City, Kansas City, MO 64108, USA 1. Key Laboratory of Biomedical Information Engineering of Ministry of Education Institute of Molecular Genetics School of Life Science and Technology Xi’an Jiaotong University Xi’an 710049 China 3. Departments of Orthopedic Surgery and Basic Medical Science School of Medicine University of Missouri-Kansas City Kansas City MO 64108 USA 2. institute of Bioscience and Biotechnology School of Science Beijing Jiaotong University Beijing 100044 China

Identification of population structure can help trace population histories and identify disease genes. Structured association (SA) is a commonly used approach for population structure identification and association mapping. A major issue with SA is that its performance greatly depends on the informa-tiveness and the numbers of ancestral informative markers (AIMs). Present major AIM selection meth-ods mostly require prior individual ancestry information, which is usually not available or uncertain in practice. To address this potential weakness, we herein develop a novel approach for AIM selection based on principle component analysis (PCA), which does not require prior ancestry information of study subjects. Our simulation and real genetic data analysis results suggest that, with equivalent AIMs, PCA-based selected AIMs can significantly increase the accuracy of inferred individual ancestries compared with traditionally randomly selected AIMs. Our method can easily be applied to whole genome data to select a set of highly informative AIMs in population structure, which can then be used to identify potential population structure and correct possible statistical biases caused by population stratification.

关键词： population structure principle component analysis ancestral informative markers

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Optimal motion planning of an underactuated spacecraft using wavelet approximate method

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Progress in Natural Science:Materials International 2006年第8期16卷 868-873页

作者： GE Xinsheng, CHEN Liqun and LIU Yanzhu (beijing institute of Machinery, beijing 100085, china Department of Mechanics, Shanghai university, Shanghai 2.0072. china Department of Engineering Mechanics, Shanghai jiaotong university, Shanghai 2.0030, china) [a]beijing institute of Machiner Beijing China [b]Department of Mechanics Shanghai University Shanghai China [c]Department of Engineering Mechanics Shanghai Jiaotong University Shanghai China

An optimal motion planning scheme using wavelet approximation is proposed for an underactuated spacecraft. The motion planning of an underactuated spacecraft can be formulated as an optimal control of a drift-free system. A cost functional is used to incorporate the control energy and the final state errors. The motion planning is to determine control inputs to minimize the cost functional. Using the method of wavelet, one can transform an infinite-dimensional optimal control problem to a finite-dimensional one and use Gauss-Newton algorithm to solve it for a feasible trajectory which satisfies nonholonomic constraints. The proposed scheme has been applied to a rigid spacecraft with two momentum wheels. The numerical simulation results indicate that optimal control with wavelet approximation is an effective approach to steering an underactuated spacecraft system from the initial configuration to the final configuration.

关键词： underactuated spacecraft motion planning optimal control nonholonomic constraint wavelet analysis.

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MIXED EXCITATION IN ELECTROLUMINESENCE

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Chinese Journal of Polymer Science 2001年第6期19卷 579-583页

作者： Xu-rong Xu Xiu-lai Xu Xiao-feng Wang Xiao-hui Yang Zheng Xu Yan-bing Hou institute of Optoelectronics Technology Northern jiaotong {2. beijing 100044 china No jiaotong Univ Inst Optoelect Technol Beijing 100044 Peoples R China

Among the present three types of electric field-induced luminescence we noticed similarities between the inorganic and organic materials in electric field intensity. In this high electric field range SiO2.has three functions: acceleration, excitation and multiplication of electrons. Based on the acceleration effect, cathodoluminescence-like emission of organic molecules and polymers was found. By using the three functions of SiO2.or II-VI compounds and the heterojunction of inorganic and organic material we realized different variants of mixed excitation in electroluminescence.

关键词： cathodoluminescence-like emission mixed excitation inorganic-organic heterogeneous junction

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Analysis of Microstructure and Orientation in X80 Line Pipe Steels

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Journal of Iron and Steel Research International 2011年第S1期18卷 664-668页

作者： JI Ling-kang 1,2.LI Yang 2.3,MENG Li 3,LI He-lin 2.(1.School of Material Science and Engineering,Xi’an jiaotong university,Xi’an 710049,Shaanxi,{2. 2.CNPC Tubular Goods Research institute,Xi’an 710065,Shaanxi,{2. 3.School of Material Science and Engineering,university of Science and Technology beijing,beijing 100083,{2.) Xi An Jiao Tong Univ Sch Mat Sci & Engn Xian 710049 Shaanxi Peoples R China CNPC Tubular Goods Res Inst Xian 710065 Shaanxi Peoples R China Univ Sci & Technol beijing Sch Mat Sci & Engn Beijing 100083 Peoples R China

Microstructures in X80 line pipe were classified by SEM *** experimental results showed that the microstructures in X 80 line pipe steels were complicated consisting of polygonal ferrite,bainite and acicular *** relation within acicular ferrite was investigated systematically by means of *** sub-structures were observed maximum in acicular ferrite which gives high strength and high toughness to line pipe *** K-S orientation relation was generally observed between acicular ferrite and austenite during phase *** low energy CSL boundary characterized by Σ3 orientation relation according to Brandon criterion appeared with higher probability,which was benefit to improve the mechanical properties of line pipe *** orientations or texture of initial austenite grains could be deduced based on the Σ3 orientation relationship of acicular ferrite variants.

关键词： acicular ferrite EBSD K-S orientation relation TMCP

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KINETICS OF AUSTENITIC ISOTHERMAL DECOMPOSITION AND Mn PARTITION IN Fe-C-Mn-B ALLOYS

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Acta Metallurgica Sinica(English Letters) 1992年第4期5卷 240-244页

作者： YANG Liu Southwestern jiaotong university,Chengdu,{2.FANG Hongsheng Tsinghua university,beijing,{2.MENG Zhihe Luoyang institute of Technology,{2. Southwestern jiaotong Univ Chengdu China

A proper addition of Mn to Fe-C alloys could delay the isothermal transformation and change remarkably the TTT-curves to bay-like *** concentration of Mn at the α/γ interphase boundary and thir partition between α- and γ- phase were measured by STEM/*** results show that the partition of Mn diminishes gradually as the reaction temperature *** exists a certain temperature range with the strong- est Mn concentration spike at the interphase although no Mn partition is found between austenite and ferrite,and this temperature range is correspondent with the bay-temperature on TTT curves of the *** is thus suggests that the change of TTT-curve configuration is due to the partition of alloy *** bay-like shape is attributed to the solute drag ef- fect and the solute drag-like effect caused by the enrichment of Mn at the α/γ interphase.

关键词： TTT curve partition Mn Fe-C-Mn-B alloy solute drag

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Fuzzy Scheduling of Coupled Customers toa Queueing Network with Parallel Servers

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Systems Science and Systems Engineering 1998年第4期8卷 482-487页

作者： ZHU Xiaomin(Department of Economics College of Economics and AdministratinNorthern jiaotong university{2., china)ZHANG Runtong(institute of Information Systems College of Economics and AdministrationNorthern jiaotong university{2.,

In this paper we consider a queueing network consisting of two parallel servers and threearrival streams generated by independent Poisson sources. Each server has its own queue and receivescustomers from its own arrival stream. A third arrival stream consists of customers which place resourcedemands on both servers, which are handled separately by each server once the request is made. Eachservice time is independent and exponentially distributed. Each customer in the system pays a holdingcost per unit time. The objective is to dynamically determine the optimal scheduling policy to the thirdstream of conupled customers. based on the state of the system, so as to minimize the average cost. Thismodel is new, and has Policy implications for computer or communication networks. A fuzzy approachis presented to solve this problem. Simulation shows that the approach is efficient and promising.

关键词： Fuzzy Scheduling of Coupled Customers toa Queueing Network with Parallel Servers

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A　SUPERLINEAR　CONVERGENT　FEASIBLE　METHOD　FOR　NONLINEAR　PROGRAMMING　WITH　NONLINEAR　CONSTRAINTS

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Systems Science and Mathematical Sciences 1995年第3期8卷 193-199,201-202页

作者： GAO Ziyou HE Guoping(institute of Applied Mathematics, Academia Sinica, beijing 100080,{2.)LIU Rengkui(Northern jiaotong university, beijing 100044, china) 中科院应用数学所北京北方交通大学北京 100044

ＡＳＵＰＥＲＬＩＮＥＡＲＣＯＮＶＥＲＧＥＮＴＦＥＡＳＩＢＬＥＭＥＴＨＯＤＦＯＲＮＯＮＬＩＮＥＡＲＰＲＯＧＲＡＭＭＩＮＧＷＩＴＨＮＯＮＬＩＮＥＡＲＣＯＮＳＴＲＡＩＮＴＳ￥ＧＡＯＺｉｙｏｕ；ＨＥＧｕｏｐｉｎｇ（Ｉｎｓｔｉ... 详细信息

ＡＳＵＰＥＲＬＩＮＥＡＲＣＯＮＶＥＲＧＥＮＴＦＥＡＳＩＢＬＥＭＥＴＨＯＤＦＯＲＮＯＮＬＩＮＥＡＲＰＲＯＧＲＡＭＭＩＮＧＷＩＴＨＮＯＮＬＩＮＥＡＲＣＯＮＳＴＲＡＩＮＴＳ￥ＧＡＯＺｉｙｏｕ；ＨＥＧｕｏｐｉｎｇ（ＩｎｓｔｉｔｕｔｅｏｆＡｐｐｌｉｅｄＭａｔｈ...

关键词： Constrained optimization successive quadratic programming feasibility superlinear convergence.

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Influence of Yb^(3+) concentration on the upconversion luminescence of oxyfluoride material doped with Er^(3+)

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Science china(Physics,Mechanics & Astronomy) 2010年第2期53卷 310-314页

作者： ZHAO SuLing1,XU Zheng1,WANG LiHui2.& S. Wageh3 1 institute of Optoelectronic Technology,Key Laboratory of Luminescence and Optical Information (beijing {2. university),Ministry of Education,beijing 100044,china 2.Department of Physics,Chinese People’s Public Security university,beijing 100038,china 3 Physics & Engineering Mathematics Department Faculty of Electronic Engineering Menufiya university,Menouf 32.52.Egypt 1. institute of Optoelectronic Technology Key Laboratory of Luminescence and Optical Information (Beijing Jiaotong University) Ministry of Education Beijing 100044 China2. Department of Physics Chinese People’s Public Security University Beijing 100038 China3. Physics & Engineering Mathematics Department Faculty of Electronic Engineering Menufiya University Menouf 32952 Egypt

In this paper,a new upconversion luminescent material co-doped with Erbium and Ytterbium is reported. The upconversion luminescence transition routes and related properties are studied. The results show that the absorption and emission intensities under excitation of 980 nm laser increase with the increase of the Yb3+ concentration. The red emission is stronger than the green emission. The energy transfer process plays an important role in the upconversion mechanism.

关键词： upconversion luminescence Er3+ Yb3+

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A constitutive model of frozen soil with damage and numerical simulation for the coupled problem

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Science china(Physics,Mechanics & Astronomy) 2010年第4期53卷 699-711页

作者： ZHU ZhiWu, NING JianGuo& MA Wei 1 School of Mechanics and Engineering, Southwest jiaotong university, Chengdu 610031,{2. 2.State Key Laboratory of Explosion Science and Technology, beijing institute of Technology, beijing 100081,{2. 3 Key Laboratory of Frozen Soil Engineering, CAREERI, CAS, Lanzhou 730000,{2. 1. School of Mechanics and Engineering Southwest Jiaotong University Chengdu 610031 China2. State Key Laboratory of Explosion Science and Technology Beijing Institute of Technology Beijing 100081 China3. Key Laboratory of Frozen Soil Engineering CAREERI CAS Lanzhou 730000 China

Based on the microcosmic mechanics of composite materials, an elastic constitutive model for frozen soil with damage is presented. For frozen sandy soil with a range of ice contents and under a range of temperature conditions, quantitative results determined by this constitutive model agree with practically measured stress-strain curves. After numerically simulating the coupled water, temperature and stress fields of channel frozen and frozen roadbed using a self-developed finite-element routine, more accurate and practical calculation results for the temperature field coupled with stress, displacement and strain fields are obtained; the results match predictions and tests undertaken by earlier researchers. Our results support the reliability of our routine for calculating interdependent physical quantities of frozen soil and for describing the relationships between them. Our program can offer necessary constraints for engineering design and construction in permafrost regions.

关键词： frozen soil microcosmic mechanics roadbed coupling stress field

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Erosion-Corrosion Behaviors of High Velocity Arc Sprayed Fe-AlCr_3C_2.Coating

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Journal of Wuhan university of Technology(Materials Science) 2006年第3期21卷 29-31页

作者：徐维普 Welding institute of Materials Science and Engineering Shanghai Jiaotong University Shanghai 200030ChinaNational Key Laboratory for Remanufacturing Beijing 100072China

Iron aluminide intermetallic coatings were prepared from Fe-Al/Cr3C2.cored wires using High Velocity Are Spraying （ HVAS ） technology. Erosion and corrosion properties of HVAS sprayed Fe-Al/Cr3C2.coatings were investigated. Results show that the erosion at impingement angle of 30°is more than that of 90°. The erosion resistance of coatings was enhanced uith the inereaase of temperature. Coatings had a better erosion resislance than substrwles. The erosion changed from ductile behariors to brittle behaviors above 450℃ . At high temperature, the erosion resistances were superior to those at low temperwlure and roonl temperwlure. Cowlings had much higher corrosion properties than substrates. The temperature had a little effect on the corrosion resistance of coatings ; The corrosion losing of cowlings increased slowly with the increase of corrosion time. The HVAS-sprayed Fe-Al/Cr3C2.coatings exhibited a high bond strength and hardness.

关键词： Fe-Al/Cr3C2.cowlings high velocity arc spraying erosion corrosion

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