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Application　of　a　Double－Wollaston－prism　Laser　Differential　Interferometer　in　Plasma　Focus

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Chinese Journal of Lasers 1996年第5期B5卷 461-466页

作者： LU Mingfang YANG Tsinchi HAN Min (tsinghua university, beijing 100084, china) tsinghua Univ Beijing China

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关键词： laser differential interferometry plasma focus

On fixed-points and singular values of transcendental meromorphic functions

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Science china Mathematics 2010年第3期53卷 887-894页

作者： ZHENG JianHua Department of Mathematical Sciences, tsinghua university, beijing 100084, china Department of Mathematical Sciences Tsinghua University

In this paper we make a further discussion of a relationship between the number of fixed-points and distribution of singular values along the round annuli centered at the origin of a transcendental meromorphic function. To attain our purpose we first establish a fundamental inequality for the modulus of derivative of a holomorphic covering mapping whose image is an annulus by virtue of the hyperbolic metric. The inequality is of independent significance. We make a simple survey on some domain constants for hyperbolic domains.

关键词： meromorphic functions fixed points singular points hyperbolic metric covering mapping

Real-time reliability prediction for dynamic systems with both deteriorating and unreliable components

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Science in china(Series F) 2009年第11期52卷 2234-2246页

作者： XU ZhengGuo1,2, JI YinDong2,3 & ZHOU DongHua1,2? 1 Department of Automation, tsinghua university, beijing 100084, china 2 tsinghua National Laboratory for Information Science and Technology, tsinghua university, beijing 100084, china 3 Research Institute of Information Technology (RIIT), tsinghua university, beijing 100084, china Department of Automation Tsinghua University Beijing China tsinghua National Laboratory for Information Science and Technology Tsinghua University Beijing China Research Institute of Information Technology (RIIT) Tsinghua University Beijing China

As an important technology for predictive maintenance, failure prognosis has attracted more and more attentions in recent years. Real-time reliability prediction is one effective solution to failure prognosis. Considering a dynamic system that is composed of normal, deteriorating and unreliable components, this paper proposes an integrated approach to perform real-time reliability prediction for such a class of systems. For a deteriorating component, the degradation is modeled by a time-varying fault process which is a linear or approximately linear function of time. The behavior of an unreliable component is described by a random variable which has two possible values corresponding to the operating and malfunction conditions of this component. The whole proposed approach contains three algorithms. A modified interacting multiple model particle filter is adopted to estimate the dynamic system＇s state variables and the unmeasurable time-varying fault. An exponential smoothing algorithm named the Holt＇s method is used to predict the fault process. In the end, the system＇s reliability is predicted in real time by use of the Monte Carlo strategy. The proposed approach can effectively predict the impending failure of a dynamic system, which is verified by computer simulations based on a three-vessel water tank system.

关键词： reliability failure prognostics dynamic systems fault prediction particle filtering interacting multiple model exponential smoothing,predictive maintenance

Buffer planning for application-specific networks-on-chip design

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Science in china(Series F) 2009年第4期52卷 547-558页

作者： YIN ShouYi1,2,LIU LeiBo1,2 & WEI ShaoJun1,2 1 Institute of Microelectronics,tsinghua university,beijing 100084,china 2 National Laboratory for Information Science and Technology,tsinghua university,beijing 100084,china Institute of Microelectronics Tsinghua University National Laboratory for Information Science and Technology Tsinghua University

Networks-on-chip （NoC） is a promising communication architecture for next generation SoC. The size of buffer used in on-chip routers impacts the silicon area and power consumption of NoC dominantly. It is important to plan the total buffer-size and each router buffer-allocation carefully for an efficient NoC design. In this paper, we propose two buffer planning algorithms for application-specific NoC design. More precisely, given the traffic parameters and performance constraints of target application, the proposed algorithms automatically determine minimal buffer budget and assign the buffer depth for each input channel in different routers. The experimental results show that the proposed algorithms can significantly reduce total buffer usage and guarantee the performance requirements.

关键词： buffer planning networks-on-chip (NoC) design automation optimization

Fabrication of Grain-oriented (Bi,Pb)_2Sr_2Ca_2Cu_3O_x Superconducting Tapes Using Magnetic Field and Vibration Technique

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Journal of Materials Science & Technology 1998年第1期14卷 86-88页

作者： Yanwei MA and Xianjin WANG (Dept. of Metal Forming, university of Science and Technology beijing, beijing 100083, china)Zutang WANG (tsinghua university, beijing 100084, china) Dept. of Metal Forming University of Science and Technology Beijing Beijing 100083 China tsinghua university Beijing 100084 China

Highly textured (Bi,Pb)2Sr2Ca2Cu3Ox superconducting tapes have been fabricated by means of magnetic-field and vibration technique. This method is an effective way of improving the degree of grain alignment and density of oxide core in tapes after heat treatment and pressing *** of above 20% was increased than that without treatment.

关键词： Bi,Pb Pb Sr Fabrication of Grain-oriented x Superconducting Tapes Using Magnetic Field and Vibration Technique Ca Cu

Diagnostics for the structure of AGNs'broad line regions with reverberation mapping data:confirmation of the two-component broad line region model

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Science china(Physics,Mechanics & Astronomy) 2010年第S1期53卷 196-201页

作者： ZHU Ling1 & ZHANG ShuangNan2 1 Department of Physics and tsinghua Center for astrophysics,tsinghua university,beijing 100084,china 2 Key Laboratory of Particle astrophysics,Institute of High Energy Physics,Chinese Academy of Sciences,beijing 100049,china Department of Physics and tsinghua Center for astrophysics Tsinghua University Beijing China Key Laboratory of Particle astrophysics Institute of High Energy Physics Chinese Academy of Sciences Beijing China

We re-examine the ten Reverberation Mapping(RM) sources with public data based on the two-component model of the Broad Line Region(BLR).In fitting their broad Hβ Mlines,six of them only need one Gaussian component,one of them has a double-peak profile,one has an irregular profile,and only two of them need two components,i.e.,a Very Broad Gaussian Component(VBGC) and an Inter-Mediate Gaussian Component(IMGC).The Gaussian components are assumed to come from two distinct regions in the two-component model;they are the Very Broad Line Region(VBLR) and the Inter-Mediate Line region(IMLR).The two sources with a two-component profile are Mrk 509 and NGC *** time lags of the two components of both sources satisfy tIMLR/tVBLR=V 2VBLR/V 2IMLR,where tIMLR and tVBLR are the lags of the two components while VIMLR and VVBLR represent the mean gas velocities of the two regions,supporting the two-component model of the BLR of Active Galactic Nuclei(AGNs).The fact that most of these ten sources only have the VBGC confirms the assumption that RM mainly measures the radius of the VBLR;consequently,the radius obtained from the R-L relationship mainly represents the radius of ***,NGC 4051,with a lag of about 5 days in the one component model,is an outlier on the R-L relationship as shown in Kaspi et al.(2005);however this problem disappears in our two-component model with lags of about 2 and 6 days for the VBGC and IMGC,respectively.

关键词： broad line region AGN Reverberation Mapping cross correlation

HIGH TEMPERATURE OXIDATION AND STRUCTURE OF SCALE AND WHISKERS FOR Fe-Ni-Cr SEALING ALLOYS

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Acta Metallurgica Sinica(English Letters) 1993年第8期6卷 147-150页

作者： DONG Zhili MA Jusheng TANG Xiangyun YOU Liang tsinghua university,beijing,china lecturer Department of Materials Science and Engineering,tsinghua university,beijing 100084,china tsinghua Univ Beijing China

The oxidation rate,the growth,morphology and structure of oxide scale and whiskers for Fe-Ni-Cr sealing alloys in H_2-H_2O atmosphere at high temperatures have been studied. The growth rate of scale is controlled by *... 详细信息

关键词： oxidation oxide scale oxide whisker Fe-Ni-Cr sealing alloy

A formal method to real-time protocol interoperability testing

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Science in china(Series F) 2008年第11期51卷 1723-1744页

作者： WANG ZhiLiang1,3,YIN Xia2,3 & JING ChuanMing2,3 1 Network Research Center,tsinghua university,beijing 100084,china 2 Department of Computer Science and Technology,tsinghua university,beijing 100084,china 3 tsinghua National Laboratory for Information Science and Technology(TNList) ,beijing 100084,china Network Research Center Tsinghua University Department of Computer Science and Technology Tsinghua University tsinghua National Laboratory for Information Science and Technology (TNList)

Interoperability testing is an important technique to ensure the quality of implementations of network communication protocol. In the next generation Internet protocol, real-time applications should be supported effectively. However, time constraints were not considered in the related studies of protocol interoperability testing, so existing interoperability testing methods are difficult to be applied in real-time protocol interoperability testing. In this paper, a formal method to real-time protocol interoperability testing is proposed. Firstly, a formal model CMpTIOA （communicating multi-port timed input output automata） is defined to specify the system under test （SUT） in real-time protocol interoperability testing; based on this model, timed interoperability relation is then defined. In order to check this relation, a test generation method is presented to generate a parameterized test behavior tree from SUT model; a mechanism of executability pre-determination is also integrated in the test generation method to alleviate state space explosion problem to some extent. The proposed theory and method are then applied in interoperability testing of IPv6 neighbor discovery protocol to show the feasibility of this method.

关键词： protocol testing interoperability testing real-time testing test generation timed input output automata(TIOA)

The General Machining Process Simulator GMPS

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Journal of Systems Engineering and Electronics 1994年第3期5卷 73-79页

作者： Xiao Tianyuan, Yang Gang & Li Xin (Department of Automation, tsinghua university, beijing, china, 100084) Department of Automation Tsinghua University Beijing China 100084

Automated manufacturing system is characterized by flexibility. It aims at producing a variety of products with virtually no time loses to change over from one part to the next. In this paper, the Machining Process Simulator GMPS is introduced, which can be used as a supported environment for machining process. It can be executed off-line or on-line in manufacturing systems in order to predict the collisions of tool with machined workpieces, fixtures or pallets. First, the functional model of GMPS is described, then adopted critical techniques in the simulator are introduced. Finally, an application of GMPS in CIMS ERC of china is presented.

关键词： Machining process simulator Modeling Front End DNC NC code translator 3D animation detecting collision.