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research ON PRODUCT INNOVATION DESIGN IN VIRTUAL PRODUCT DEVELOPMENT

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Chinese Journal of Mechanical Engineering 2002年第4期15卷 353-359页

作者： Wu Qunbo Zhang Linxuan Xiao Tianyuan Long Xinghai State CIMS Engineering research center, tsinghua university, beijing 100084, china State CIMS Engineering research center Tsinghua University Beijing 100084 China

An integrated template of virtual product development alters primarilysequential tradition mode of product life cycle. The template integrates all processes of productdevelopment using digital modem. An environment of virtual product development provides productdevelopment environment of integration, communion, network, concurrent and collaboration. Combiningdevelopment of new rapier loom, an innovated design process is researched in virtual productdevelopment, which consists three portions: constructing an integration development environment,innovation design and manufacturing simulation. The innovated design process realizes reversedesign, mechanism concept design, structural design and analysis, performance analysis andmanufacturing process simulation of virtual product, which can enhance greatly product performanceand reduce cost and development cycle of new product.

关键词： virtual product development innovation design product data management

A measurement error model for microarray data analysis

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Progress in Natural Science:Materials International 2005年第7期15卷 614-620页

作者： ZHOU Yiming and CHENG Jing ( Department of Biological Sciences and Biotechnology, tsinghua university, beijing 100084, china State Key Laboratory of Biomembrane and Membrane Biotechnology, tsinghua university, beijing 100084, china National Engineering research center for beijing Biochip Technology, 18 Life Science Parkway, beijing 102206, china) Department of Biological Sciences and Biotechnology Tsinghua University Beijing 100084 China. State Key Laboratory of Biomembrane and Membrane Biotechnology Tsinghua University Beijing 100084 China. National Engineering research center for beijing Biochip Technology 18 Life Science Parkway Beijing 102206 China

Microarray technology has been widely used to analyze the gene expression levels by detecting fluorescence intensity in a high throughput fashion. However, since the measurement error produced from various sources in microarray experiments is heterogeneous and too large to be ignored, we propose here a measurement error model for microarray data processing, by which the standard deviation of the measurement error is demonstrated to be linearly increased with fluorescence intensity. A robust algorithm, which estimates the parameters of the measurement error model from a single microarray without replicated spots, is provided. The model and algorithm for estimating of the parameters from a given data set are tested on both the real data set and the simulated data set, and the result has been proven satisfactory. And, combining the measurement error model with traditional Z-test method, a full statistical model has been developed It can significantly improve the statistical inference for identifying differentially expressed genes.

关键词： microarray measurement error model parameter estimation differentially expressed genes.

research ON CAPP/SCHEDULING INTEGRATION MULTI-AGENT SYSTEM MODEL AND IMPLEMENTATION

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Chinese Journal of Mechanical Engineering 2003年第4期16卷 348-351页

作者： Wang YunliXiao TianyuanDuan GuanghongWang XiankuiNational CIMS Engineeringresearch center,tsinghua university,beijing 100084, china National CIMS Engineering research center Tsinghua University Beijing 100084 China

A design methodology for multi-agent systems is proposed. The systemicframework of CAPP and scheduling integrated multi-agent system according to design methodology isresearched. Agent model, composition model and cooperation model are discussed respectively in themulti-agent system. Static composition model and dynamic running model of CAPP and schedulingintegrated system are presented in composition model. Communication model, language model andprotocol model are discussed in corporation model. CSIMAS, CAPP and scheduling integratedmulti-agent prototype system, is developed to illuminate system model. Multiple non-rotational partsare tested in distributed process planning and scheduling environment of CSIMAS.

关键词： Multi-agent systems Design methodology CAPP Scheduling Integration

New evidence for lack of CMB power on large scales

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Science china(Physics,Mechanics & Astronomy) 2010年第3期53卷 567-570页

作者： LIU Hao1 & LI TiPei1,2,3 1 Key Laboratory of Particle Astrophysics, Institute of High Energy Physics, Chinese Academy of Sciences, beijing 100049, china 2 Department of Physics & center for Astrophysics, tsinghua university, beijing 100084, china 3 Department of Engineering Physics & center for Astrophysics, tsinghua university, beijing 100084, china 1. Key Laboratory of Particle Astrophysics Institute of High Energy Physics Chinese Academy of Sciences Beijing 100049 China2. Department of Physics & Center for Astrophysics Tsinghua University Beijing 100084 China3. Department of Engineering Physics & Center for Astrophysics Tsinghua University Beijing 100084 China

A digitalized temperature map is recovered from the first light sky survey image published by the Planck team, from which an angular power spectrum of the cosmic microwave background (CMB) is derived. The amplitudes of the low multipoles (low-l) measured from the preliminary Planck power spectrum are significantly lower than those reported by the WMAP team. Possible systematical effects are far from enough to explain the observed low-l differences.

关键词： cosmology cosmic microwave background data analysis

Moran sets and Moran classes

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Chinese Science Bulletin 2001年第22期46卷 1849-1856页

作者： WEN ZhiyingDepartment of Mathematics, tsinghua university, beijing 100084, china Department of Mathematics Tsinghua University Beijing China

The purpose of this survey is to present Moran sets and Moran classes which generalize the classical self-similar sets from the following points: (i) The placements of the basic sets at each step of the constructions can be arbitrary; (ii) the contraction ratios may be different at each step; and (iii) the lower limit of the contraction ratios permits zero. In this discussion we will present geometrical properties and results of dimensions of these sets and classes, and discuss conformal Moran sets and random Moran sets as well.

关键词： Moran set Moran classes dimension.

Extremal eigenvalues of measure differential equations with fixed variation

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Science china Mathematics 2010年第10期53卷 2573-2588页

作者： ZHANG MeiRong 1,2 1 Department of Mathematical Sciences,tsinghua university,beijing 100084,china 2 Zhou Pei-Yuan center for Applied Mathematics,tsinghua university,beijing 100084,china 1. Department of Mathematical Sciences Tsinghua University Beijing 100084 China2. Zhou Pei-Yuan Center for Applied Mathematics Tsinghua University Beijing 100084 China

In this paper we will study eigenvalues of measure differential equations which are motivated by physical problems when physical quantities are not absolutely *** taking Neumann eigenvalues of measure differential equations as an example,we will show how the extremal problems can be completely solved by exploiting the continuity results of eigenvalues in weak* topology of measures and the Lagrange multiplier rule for nonsmooth *** results can give another explanation for extremal eigenvalues of SturmLiouville operators with integrable potentials.

关键词： measure differential equation eigenvalue extremal value weak* topology Frechét derivative sub-differential

Development of SOM combustion model for Reynolds-averaged and large-eddy simulation of turbulent combustion and its validation by DNS

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Science china(Technological Sciences) 2008年第8期51卷 1073-1086页

作者： ZHOU LiXing Department of Engineering Mechanics, tsinghua university, beijing 100084, china Department of Engineering Mechanics Tsinghua University Beijing 100084 China

The derivation and closure methods of the second-order moment (SOM) combus- tion model are proposed. The application of this model to Reynolds averaged (RANS) and large-eddy simulation (LES) of turbulent swirling diffusion combustion, jet diffusion combustion, and bluff-body stabilized premixed combustion is sum- marized. It is indicated that the SOM model is much better than the eddy-beak-up (EBU) and presumed PDF models widely used in commercial software and engi- neering. The SOM modeling results are close to those obtained using the most accurate but much more complex PDF equation model. Moreover, it can save much more computation time than the PDF equation model. Finally, the SOM model is validated by the direct numerical simulation (DNS) of turbulent reacting channel flows.

关键词： turbulent combustion second-order moment model Reynolds averaged simulation large-eddy simulation

EXACT NONREFLECTING BOUNDARY CONDITIONS FOR AN ACOUSTIC PROBLEM IN THREE DIMENSIONS

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Journal of Computational Mathematics 2003年第1期21卷 15-24页

作者： Houde Han Chunxiong Zheng (Department of Mathematical Sciences, tsinghua university, beijing 100084, china) Department of Mathematical Sciences Tsinghua University 北京 100084

In this paper, nonreflecting artificial boundary conditions are considered for an acoustic problem in three dimensions. With the technique of Fourier decomposition under the orthogonal basis of spherical harmonics, three kinds of equivalent exact artificial boundary conditions are obtained on a spherical artificial boundary. A numerical test is presented to show the performance of the method.

关键词： Exterior problem Nonreflecting artificial boundary condition Acoustic equa-tion Three-dimensions.

THE GLOBAL ARTIFICIAL BOUNDARY CONDITIONS FOR NUMERICAL SIMULATIONS OF THE 3D FLOW AROUND A SUBMERGED BODY

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Journal of Computational Mathematics 2003年第4期21卷 435-450页

作者： Hou-de Han Xin Wen (Department of Mathematical Sciences, tsinghua university, beijing 100084, china) Department of Mathematical Sciences Tsinghua University Beijing 100084 China

We consider the numerical approximations of the three-dimensional steady potential flow around a body moving in a liquid of finite constant depth at constant speed and distance below a free surface in a channel. One vertical side is introduced as the upstream artificial boundary and two vertical sides are introduced as the downstream artificial boundaries. On the artificial boundaries, a sequence of high-order global artificial boundary conditions are given. Then the original problem is reduced to a problem defined on a finite computational domain, which is equivalent to a variational problem. After solving the variational problem by the finite element method, we obtain the numerical approximation of the original problem. The numerical examples show that the artificial boundary conditions given in this paper are very effective.

关键词： Ship wave Potential flow Global artificial boundary condition Finite element method.