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A circular zone partition method for identifying Duffing oscillator state transition and its application to BPSK signal demodulation

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Science China(Information Sciences) 2011年第6期54卷 1274-1282页

作者： FU YongQing 1 , WU DongMei 1 , ZHANG Lin 2 & LI XingYuan 1 1 college of Information and Communication engineering, Harbin engineering University, Harbin 150001, China 2 college of Underwater Acoustic engineering, Harbin engineering University, Harbin 150001, China 1. college of Information and Communication engineering Harbin Engineering University Harbin 150001 China2. College of Underwater Acoustic Engineering Harbin Engineering University Harbin 150001 China

When a Duffing oscillator is applied to signal detection, identifying its state transition is indispensable. Due to lack of an effective method for automatically distinguishing the state transition, phase analysis is extensively used. However, it needs ocular estimation to identify phase pattern corresponding to transition of Duffing oscillator. Hence it is not fit for communication signal demodulation. To solve the problem, this paper proposes a method, called circular zone partition (CZP), for partitioning trajectory on the phase plane of Duffing oscillator. First, a computing model for Duffing oscillator is described. Then, the fundamental principle and algorithm for the CZP method are discussed. Meanwhile the equation of a circular zone divider and its realization are presented. Thus, by way of the divider, the two-dimensional phase trajectory pattern of Duffing oscillator driven by an external signal can be transformed into the one-dimensional time signal, whose envelop after being filtered is able to indicate the state transition, i.e. the presence or the absence of external signal. Finally, to verify the effect of the CZP method on binary phase shifted keying (BPSK) signal demodulation, two examples are presented and simulation results show that this CZP method is accurate and valid for BPSK signal demodulation.

关键词： chaos nonlinear oscillators signal detection digital communication receivers

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Training, simulation, restoration expert system for power grid

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Journal of Central South University of Technology 2001年第1期8卷 69-73页

作者： LUO An,CHEN Qian (college of Information engineering, Central South University, Changsha 410083, China) 1. college of Information engineering Central South University 410083 Changsha China

The paper introduces some technology for training, simulation, restoration expert system of power grid, the structure of the system including function composition, hardware and software composition are discussed, knowledge representation and the method to establish device graphical library for expert system are given, the fault setting and diagnosis for training and simulation as well as restoration technology with deep first searching arithmetic and heuristic inference are presented. The research provides a good base for developing the training, simulation, restoration system of power companies.

关键词： training simulation restoration expert system power grid

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Coupling analysis of unsteady seepage and stress fields in discrete fractures network of rock mass in dam foundation

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Science China(Technological Sciences) 2011年第S1期54卷 133-139页

作者： CHAI JunRui 1,2 & XU WeiSheng 2 1 college of Hydraulic and Environmental engineering,China Three Gorges University,Yichang 443002,China 2 college of Hydropower engineering,Xi’an University of Technology,Xi’an 710048,China 1. college of Hydraulic and Environmental engineering China Three Gorges University Yichang 443002 China2. College of Hydropower Engineering Xi’an University of Technology Xi’an 710048 China

The drag force of water flow through single fracture and the coupling characteristics of seepage and stress in single fracture surface are analyzed,and a three dimensional model of coupled unsteady seepage and stress fields is *** model is used to the analysis of foundation rock mass of a high *** the coupling effects are considered,the changes of boundary heads have less influence on the inner head of rock mass,and the strong permeability of main fractures *** the coupling effects are not considered,the fractures distribution affects the inner head more *** the upstream water head declines,the inner head of dam foundation slightly declines and the hydraulic gradient distribution becomes smoother.A bigger upstream water level declining velocity has a stronger lag effect,meanwhile the values of stress components change more *** the upstream water level declining velocity directly affects the stability of rock mass in dam foundation and we should take into account the above factors to make sure the safety of the dam during reservoir level fluctuation period.

关键词： hydraulic engineering unsteady seepage stress coupling fractures network rock mass

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EXTRAPOLATING METHOD IN PLOT FOR FATIGUE LIFE PREDICTION OF COMPONENTS

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中国有色金属学会会刊：英文版 1996年第3期6卷 153-156页

作者： Liu Yilun Wang Ailun(college of Mechanical and Electrical engineering,Central South University of Technology, Changsha 410083) CENT S UNIV TECHNOL COLL MECH & ELECT ENGNCHANGSHA 410083PEOPLES R CHINA

ＥＸＴＲＡＰＯＬＡＴＩＮＧＭＥＴＨＯＤＩＮＰＬＯＴＦＯＲＦＡＴＩＧＵＥＬＩＦＥＰＲＥＤＩＣＴＩＯＮＯＦＣＯＭＰＯＮＥＮＴＳ￥ＬｉｕＹｉｌｕｎ；ＷａｎｇＡｉｌｕｎ（ＣｏｌｌｅｇｅｏｆＭｅｃｈａｎｉｃａｌａｎｄＥｌｅｃｔ... 详细信息

ＥＸＴＲＡＰＯＬＡＴＩＮＧＭＥＴＨＯＤＩＮＰＬＯＴＦＯＲＦＡＴＩＧＵＥＬＩＦＥＰＲＥＤＩＣＴＩＯＮＯＦＣＯＭＰＯＮＥＮＴＳ￥ＬｉｕＹｉｌｕｎ；ＷａｎｇＡｉｌｕｎ（ＣｏｌｌｅｇｅｏｆＭｅｃｈａｎｉｃａｌａｎｄＥｌｅｃｔｒｉｃａｌＥｎｇｉｎｅｅｒｉｎｇ，...

关键词： extrapolation plot fatigue life

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Series-based approximate approach of optimal tracking control for nonlinear systems with time-delay

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Progress in Natural Science:Materials International 2008年第12期18卷 1571-1576页

作者： Gongyou Tang~a Mingqu Fan~(a,b) a college of Information Science and engineering,Ocean University of China,Qingdao 266100,China b college of Information and engineering,Shandong University of Science and Technology,Jinan 250031,China [a]college of Information Science and engineering Ocean University of China Qingdao 266100 China [b]college of Information and engineering Shandong University of Science and Technology Jinan 250031 China

The optimal output tracking control (OTC) problem for nonlinear systems with time-delay is *** a series-based approx- imate approach,the original OTC problem is transformed into iteration solving linear two-point boundary value problems without time- *** OTC law obtained consists of analytical linear feedback and feedforward terms and a nonlinear compensation term with an infinite series of the adjoint *** truncating a finite sum of the adjoint vector series,an approximate optimal tracking control law is obtained.A reduced-order reference input observer is constructed to make the feedforward term physically *** exam- ples are used to test the validity of the series-based approximate approach.

关键词： Nonlinear systems Time-delay Tracking control Optimal control Observer

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Theoretical analysis of alloy multiplying factor by the empirical electron theory of solids and molecules

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Science China(Technological Sciences) 2007年第6期50卷 807-814页

作者： SONG YuePeng1,2, LIU GuoQuan2, LI ZhiLin3, FENG ChengMing1 1 Mechanical and Electronic engineering college, Shandong Agricultural University, Tai’an 271018, China 2 college of Materials Science and engineering, University of Science and Technology, Beijing 100083, China 3 college of Material Science and engineering, Beijing University of Chemical Technology, Beijing 100029, China Mechanical Electronic engineering college Shandong Agricultural University Tai’an 271018 China college of Materials Science engineering University of Science Technology Beijing 100083 China college of Material Science engineering Beijing University of Chemical Technology Beijing 100029 China

By introducing the distribution probability of structural units in austenite contain- ing alloying elements and considering its effects on phase transformation, this paper establishes a calculation model of distribution probability of structural units. A new valence electron structure (VES) parameter-transformation effect coefficient of alloying elements (HL), is defined and then studied both theoretically and ex- perimentally. The relationship between the parameter HL and the multiplying factor (the quenching capability factor) of alloying elements is studied. The results indi- cate that the two parameters (HL and the quenching capability factor) have the same variation characteristic and substance feature. Therefore, the multiplying factor virtually expresses the relative quantity of structural units in the alloying elements-containing austenite.

关键词： multiplying factor (the quenching capability factor), empirical electron theory of solids and molecules, transformation effect coefficient of alloying elements, structural units in austenite containing alloying elements

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Synthesis and Crystal Structure of 4,6Di-tert-butyl-2-hydroxy-3-(N-1-phenylethyliminomethyl) phenyl bis(triphenylphosphine)palladium bromide

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Chinese Journal of Structural Chemistry 1999年第4期18卷 54-59页

作者： XU JiaXi\ ZHANG ZeYing\= (college of Chemistry and Molecular engineering, Peking University, Beijing 100871, China) Coll. of Chem. and Molec. Eng. Peking University Beijing 100871 China

１ＩＮＴＲＯＤＵＣＴＩＯＮＰａｌａｄｉｕｍｃｏｍｐｌｅｘｅｓｓｕｃｈａｓｔｅｔｒａｋｉｓ（ｔｒｉｐｈｅｎｙｌｐｈｏｓｐｈｉｎｅ）ｐａｌａｄｉｕｍａｒｅａｋｉｎｄｏｆｉｍｐｏｒｔａｎｔｃａｔａｌｙｓｔｓｉｎｔｈｅｒｅａ... 详细信息

１ＩＮＴＲＯＤＵＣＴＩＯＮＰａｌａｄｉｕｍｃｏｍｐｌｅｘｅｓｓｕｃｈａｓｔｅｔｒａｋｉｓ（ｔｒｉｐｈｅｎｙｌｐｈｏｓｐｈｉｎｅ）ｐａｌａｄｉｕｍａｒｅａｋｉｎｄｏｆｉｍｐｏｒｔａｎｔｃａｔａｌｙｓｔｓｉｎｔｈｅｒｅａｃｔｉｏｎｏｆｃａｒｂｏｎｃａｒ...

关键词： palladium complex synthesis molecular structure crystal structure

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AN ORDINARY DIFFERENTIAL EQUATION FOR THE 2D TRANSIENT FREE-SURFACE GREEN FUNCTIONS

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Journal of Hydrodynamics 2002年第2期14卷 24-28页

作者： Duan Wen-yang college of Shipbuilding engineering, Harbin engineering University, Harbin 150001, ChinaPrice W.G. School of engineering Sciences, Ship Science, University of Southampton, UK Coll. of Shipbuilding Eng. Harbin Eng. Univ. Harbin 150001 China Sch. of Eng. Sci. Ship Sci. Univ. of Southampton Southampton United Kingdom

Based on the Laplace transform an ordinary differential equation for the two-dimensional time-domain free-surface Green function in ship hydrodynamics is presented. The results for 2D Green function and its horizontal derivative are fifth-order ODEs and the vertical derivative satisfies a fourth-order ODE. All of these results may be used to accelerate the numerical computations for the time-domain BEM in marine hydrodynamics.

关键词： ship hydrodynamics time-domain Green function Laplace transform

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A new generation of plastic optical fibers and its functional exploiting

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Science China(Technological Sciences) 2008年第12期51卷 2197-2207页

作者： YU RongJin & ZHANG Bing college of Information Science and engineering,Yanshan University,Qinhuangdao 066004,China college of Information Science and engineering Yanshan University Qinhuangdao 066004 China

A major problem of plastic optical fibers(POFs) is large transmission loss in comparison with silica *** adopting a new optical fiber structure,hollow-core Bragg fiber with cobweb-structured cladding,which can suppress the absorption losses of constituent materials by a factor of about 104―106,the problem of POFs with large losses is solved *** the advantage of flexibility and easy bending,the POFs with this structure can guide light with low transmission loss for information and energy in the wavelength range of visible light to terahertz(THz) wave(0.4―1000 μm).This new generation of POFs will find many applications.

关键词： plastic optical fiber hollow-core Bragg fiber cobweb-structured cladding visible light infrared light terahertz wave circular-polarization single-mode

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STUDY ON NEW METHOD OF IDENTIFYING GEOMETRIC ERROR PARAMETERS FOR NC MACHINE TOOLS

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Chinese Journal of Mechanical engineering 2001年第3期14卷 198-202,206页

作者： Yun Jintian,Wang Shuxin,Liu Libing,Liu Youwu (college of Mechanical engineering, Tianjin University) 天津大学机械学院天津

The methods of identifying geometric error parameters for NC machine tools are introduced. According to analyzing and comparing the different methods, a new method-displacement method with 9 lines is developed based on the theories of the movement errors of multibody system (MBS). A lot of experiments are also made to obtain 21 terms geometric error parameters by using the error identification software based on the new method.

关键词： NC machine tools Geometric error Parameter identification Multibody system

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