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Study On Clamped-Clamped Beam in-plane Capacitive Resonators

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Study On Clamped-Clamped Beam in-plane Capacitive Resonators

2008 International Conference on Optical Instruments and technology

作者： Yingxia Jin~(a,b),Yaquan Tang~a,Xiaomei Yu~(*a) a institute of Microelectronics,Peking University,beijing china,100871 b School of Electronics engineering and computer Science,beijing institute of technology,beijing china,100081

A clamped-clamped beam(CC beam)in-plane capacitive resonator with 100nm gap has been analyzed and fabricated by silicon micromachining technique in this *** nonlinearity effects in this device and the resonant mode of the main structure are analyzed and the overall system dynamics of motion equation and general solution are given *** simulation results of resonant mode indicate that the structure size of the beam has great influence on the resonant frequency of ***,with the high aspect-ratio combined poly- and single-crystal silicon micromachining technology(HARPSS),100nm gap in-piane capacitive resonator has been fabricated.

关键词： MEMS capacitive resonator clamped-clamped beam resonant mode resonant frequency HARPSS

CA Investment Casting Process of Complex Castings

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厦门大学学报（自然科学版） 2002年第S1期41卷 17-18页

作者： WU Jian-tao, FENG Di, XIE Yun-peng, LI Jun-tao, KONG Sheng-guo (Superalloy institute of Central Iron & Steel institute, beijing 100081, china)

CA (computer aided) investment casting technique used in superalloy castings of aerospace engine parts was presented. CA investment casting integrated computer application, RP (Rapid Prototyping) process, solidification simulation and investment casting process. It broke the bottle neck of making metal die. Solid model of complex parts were produced by UGII or other software, then translated into STL(Stereolithography) file, after RP process of SLS(Selective Laser Sintering), wax pattern used in investment casting can be acquired without metal die in short time. These can reduce period and cost greatly of complex superalloy parts development of engine. The key processes of CA investment casting were discussed. The accuracy of model translation should match that of RP system. Choice of RP material, surface polishing, sintering parameter plays important role in RP process. Other processes, like solidification simulating and optimization of gate system were introduced. The conclusion was that complex parts can be produced by CA investment casting with lots of advantages. The accuracy of castings can reach CT5～7,and the smoothness can get Ra3～13 mm. These parts of engines worked well.

关键词： CA investment casting RP solidification simulation complex parts of engine

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数据仓库中CUBE大小估计算法

计算机工程与应用 2004年第4期40卷 193-194,215页

作者：刘宁宋晔北京理工大学计算机科学工程系北京100081

文章叙述了数据仓库中Cube估计的三个相关算法,提出了一种优化的估计方法。这种新的优化方法在一定程度上弥补了常用估计方法的缺陷,大大提高了估计值的准确性。Cube的大小估计对于数据仓库进行多维分析是非常重要的。原因是为了提高多... 详细信息

文章叙述了数据仓库中Cube估计的三个相关算法,提出了一种优化的估计方法。这种新的优化方法在一定程度上弥补了常用估计方法的缺陷,大大提高了估计值的准确性。Cube的大小估计对于数据仓库进行多维分析是非常重要的。原因是为了提高多维分析的查询速度,要进行一定程度的预计算,这种计算是相当复杂的,而且会占用大量数据库的存储空间,因此预先估计出所需空间大小是非常必要的。

关键词：数据仓库 CUBE 大小估计

Study on the Performance of the nonlinear Joint Transform Correlator

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Chinese Journal of Lasers 1997年第2期B6卷 122-130页

作者： QIN Yuwen GE BaozhenCHEN Ximing ZHANG Yimol JIAN Shuisheng(institute of Lightwave technology,Northern Jiaotong University, beijing 100044)(institute of Optoelectronic and Precision Engineering , Tianjin University, Tianjin 300072 china) Northern Jiaotong Univ Beijing China

We present the nonlinear joint transform correlation computer simulation results and the optical experimental results of the scale and rotation varying objects, as well as the statistical experimental results of the autocorrelation peak distribution of the object. The given experimental results show clearly that the optical experimental system is a nonlinear joint transform correlation system and the distribution of the autocorrelation peak is to some extent random. Correlation peak signal intensity of the nonlinear joint transform correlation system has no obvious variation when the scale variation of the object is less than 10% or the rotation angle variation of the object is less than 5 degrees.

关键词： optical pattern recognition real-time joint transform correlation nonlinear joint transform correlation

The Performance Analysis of Traffic Channel Coding in Digital Trunking System

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Journal of Systems Engineering and Electronics 2001年第2期12卷 30-35页

作者： Tan Xuezhi, Su Min & Zhang Naitong Communication Research center of Harbin institute of technology, 150001, P R china Communication Research center of Harbin institute of technology 150001 P.R. China

The encoding and decoding processes of traffic channel in digital trunking system are studied. On the basis of computer simulation, the BER (bit error ratio) with different RCPC decoding step is analyzed. As a result, the optimal RCPC decoding step is provided, which gives essential theoretical evidences for the implementation of digital trunking system.

关键词： Bit error rate Communication channels (information theory) Quadrature phase shift keying Signal encoding Telecommunication traffic

Application of GPRS in Fault Diagnosis Instrument

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Application of GPRS in Fault Diagnosis Instrument

第一届国际测量仪器与测试自动化学术会议

作者： Xu Xiaoli Zuo Yunbo Li ying Shi Yongchao ( The beijing Key Laboratory on Measurement and Control of Mechanical & electronical System beijing 100085 china) ( School of Mechanical and Vehicular Engineering beijing institute of technology beijing 100081 china)

＜正＞There are many sensors for the fault diagnosis instrument in the field, and a lot of data can be analyzed on the computer in the laboratory or other places. GPRS（General Packet Radio Service） can realize the wireless data transmission. A new fault diagnosis instrument based on GPRS is presented in this paper. The data for fault diagnosis can be transmitted to the places far away from the real field by GPRS. Using GPRS, the remote fault diagnosis can be realized easier. It doesn’t need many signal wires in the field and the field networks can be simplified.

关键词： GPRS rotary machine fault diagnosis.

THE LIMITING CASE OF THIELE'S INTERPOLATING CONTINUED FRACTION EXPANSION

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Journal of Computational Mathematics 2001年第4期19卷 433-444页

作者： Jie-qing Tan (institute of Applied Mathematics, College of Science and CAD/CG Division College of computer & Information Hefei, University of technology, Hefei 230009, china) 中国科学技术大学安徽合肥 230009

By means of the determinantal formulae for inverse and reciprocal differences with coincident data points, the limiting case of Thiele's interpolating continued fraction expansion is studied in this paper and given numerical example shows that the limiting Thiele's continued fraction expansion can be determined once for all instead of carrying out computations for each step to obtain each convergent as done in [3].

关键词： Continued fraction Inverse difference Reciprocal difference Expansion.

Security Communication Model of Wireless Trade System

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Security Communication Model of Wireless Trade System

The 1st Chinese Conference on Trusted Computing and Information Security

作者： ZHANG Wen-kai. ZHANG Si-yu Department of computer Science and Engineering. beijing institute of technology, beijing 100081, china beijing Netting Network Technologies Co Ltd,beijing 100088, china

This paper proposes a C/S system model for K-Java and PDA named Net-Wireless. It is a discussion and proposal on information security and solutions for K-Java handsets and PDAs in wireless network. It also explains the scheme which between client security module and server securitymodule. Also, We have developed a Security Server and a K-Java encryption module for e-commerce system and other trade systems.

关键词： wireless trade data eneryption security module K-Java

Stochastic Process Model of the Multi-UAVs Collaborative System Based on State Transition

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Stochastic Process Model of the Multi-UAVs Collaborative Sys...

4th International Conference on Modelling,Identification and Control(ICMIC 2012)

作者： Bing Li is with the (1).School of Mechatronic Engineering, beijing institute of technology, beijing 100081 china (2). Department of mathematics Hunan institute of Humanities Science and technology Loudi, Hunan 417000 china RuiZhi Mao is with the School of Mechatronic Engineering, beijing institute of technology beijing 100081 china XiaoDong Yuan is with the School of Mechatronic Engineering, beijing institute of technology beijing 100081 china Jie Li is with the School of Mechatronic Engineering, beijing institute of technology beijing 100081 china TingZhao Yi is with the Hu Bei Han Dan Mechatronics Co.LtD Xiang Yang 441021 china

Because of the enhancement of micro UAV's ability of autonomous decision as well as the continuous improvement of network data link, cooperation between multiple UAVs is made possible, In order to research the Multi-UAVs' cooperative system , This article, starting with the tactical level, tries to establish a general framework about conscious cooperation of a group of UAVs, So the paper studies the status of Multi-UAVs cooperative system under the information network, and establishes a mathematical model of cooperative system using Stochastic Process and Probability Analysis, and proposes the uniqueness and Controllability theorem for system solutions existence. The example results show that the method is reasonable.

关键词： cooperative system Stochastic Process Controllability theorem