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An Approach to RCS Computation for Complex Targets

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Journal of Systems Engineering and Electronics 1997年第4期8卷 56-60页

作者： Zhao Weijiang & Wang Maoguang xidian University, xi’an 710071, P. R. China xidian University Xi'an 710071 P. R. China

A practical approach for calculating the RCS (Radar Cross Section) of complex targets modeled with wire-grid-frame is presented. A way for generating a polyhedron model (facet-wedge model) with the wire-grid-frame dat... 详细信息

关键词： Radar cross section Geometry modeling Complex target.

Narrow-band radar imaging of spinning targets

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Science China(Information Sciences) 2011年第4期54卷 873-883页

作者： BAI XueRu,SUN GuangCai,WU QiSong,xiNG MengDao & BAO Zheng Key Laboratory for Radar Signal Processing,xidian University,xi’an 710071,China Key Laboratory for Radar Signal Processing Xidian University Xi’an China

According to the characteristics of narrow-band radar echoes from spinning targets,this paper applies the complex-valued back-projection method to image *** it accumulates the sinusoidal phase of spinning scatterers effectively,this method can obtain high resolution *** resolution and required radar pulse repetition frequency (PRF) of this method are *** imaging of fast spinning targets,however,spurious peaks appear due to azimuth down sampling with a low ***,a signal model of azimuth down-sampled echoes is created according to the compressed sensing (CS) *** an imaging method based on orthogonal matching pursuit (OMP) is proposed according to the sparsity nature of ISAR ***,the effectiveness of the proposed methods is demonstrated using simulated data.

关键词： radar imaging spinning targets complex-valued back-projection compressed sensing orthogonal matching pursuit

Immune secondary response and clonal selection inspired optimizers

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Progress in Natural Science:Materials International 2009年第2期19卷 237-253页

作者： Maoguo Gong a,Licheng Jiao a,Lining Zhang a,Haifeng Du b a Key Laboratory of Intelligent Perception and Image Understanding of Ministry of Education of China,Institute of Intelligent Information Processing,xidian University,xi’an 710071,China b School of Public Policy and Administration,xi’an Jiaotong University,xi’an 710049,China Key Laboratory of Intelligent Perception and Image Understanding of Ministry of Education of China Institute of Intelligent Information Processing Xidian University Xi’an 710071 China School of Public Policy and Administration Xi’an Jiaotong University Xi’an 710049 China

The immune system’s ability to adapt its B cells to new types of antigen is powered by processes known as clonal selection and affinity maturation. When the body is exposed to the same antigen,immune system usually calls for a more rapid and larger response to the antigen,where B cells have the function of negative adjustment. Based on the clonal selection theory and the dynamic process of immune response,two novel artificial immune system algorithms,secondary response clonal programming algorithm (SRCPA) and secondary response clonal multi-objective algorithm (SRCMOA),are presented for solving single and multi-objective optimization problems,respectively. Clonal selection operator (CSO) and secondary response operator (SRO) are the main operators of SRCPA and SRCMOA. Inspired by the clonal selection theory,CSO reproduces individuals and selects their improved maturated progenies after the affinity mat-uration process. SRO copies certain antibodies to a secondary pool,whose members do not participate in CSO,but these antibodies could be activated by some external stimulations. The update of the secondary pool pays more attention to maintain the population diversity. On the one hand,decimal-string representation makes SRCPA more suitable for solving high-dimensional function optimiza-tion problems. Special mutation and recombination methods are adopted in SRCPA to simulate the somatic mutation and receptor edit-ing process. Compared with some existing evolutionary algorithms,such as OGA/Q,IEA,IMCPA,BGA and AEA,SRCPA is shown to be able to solve complex optimization problems,such as high-dimensional function optimizations,with better performance. On the other hand,SRCMOA combines the Pareto-strength based fitness assignment strategy,CSO and SRO to solve multi-objective optimization problems. The performance comparison between SRCMOA,NSGA-Ⅱ,SPEA,and PAES based on eight well-known test problems shows that SRCMOA has better performance in converging to approximate Pareto

关键词： Clonal selection Secondary response Artificial immune systems Evolutionary algorithms

Time-frequency characteristics based motion estimation and imaging for high speed spinning targets via narrowband waveforms

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Science China(Information Sciences) 2010年第8期53卷 1628-1640页

作者： ZHANG Lei , LI YaChao, LIU Yan, xiNG MengDao & BAO Zheng National Lab for Radar Signal Processing, xidian University, xi’an 710071, China National Lab for Radar Signal Processing Xidian University Xi’an China

This paper focuses on the motion parameters estimation and inversed synthetic aperture radar (ISAR) imaging for the high-speed spinning targets via the time-frequency characteristics. Assuming that the translational motion is compensated with the available motion compensation techniques, then the residual part of translational motion and the spinning motion are estimated with high precision based on the timefrequency characteristics. Combining with the procedure of the motion estimation, a novel coherent timefrequency spectrum intensity redistribution method, coherent single range Doppler interferometry (CSRDI), is proposed, which provides higher resolution and sustain lower signal to noise rate (SNR) than the current approach. Numerical simulation confirms the validity and high precision of the proposed approaches.

关键词： ISAR time-frequency characteristics CSRDI motion estimation high speed spinning targets

Study on the beam shaping of high-power laser diode bars

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Chinese Optics Letters 2003年第8期1卷 475-476页

作者：黄伟曾晓东安毓英 School of Technical Physics Xidian University Xi'an 710071

Based on the Collins form, the intensity distribution of the resulting beam is derived when Gaussian beams of a high-power laser diode bar pass through a paraxial optical system. Then flattop beam profiles are obtained by a concave cylindrical lens, and the propagation properties are discussed in detail, such as the peak-intensity axis inclined at an angle i In addition, an expression to calculate beam angular width is presented.

关键词： Laser beams Lenses Optical systems

Virtual Organization Information Systems and its Reengineering for Agile Manufacturing

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厦门大学学报（自然科学版） 2002年第S1期41卷 223-224页

作者： ZHAO Peng-wei, DOU Yong-xiang (School of Economy and Management, xidian University, xi’ an 710071, C hina)

It is now possible to organize globally while worki ng locally: Information technologies like e-mail, the Internet, and video confere ncing to the desktop permit tight coordination of geographically dispersed worke rs across time zones and cultures. Companies are not limited to physical locatio ns for providing products and services. Networked information systems are allowi ng companies to coordinate their geographically distributed capabilities as virt ual organizations. In order for organizations to succeed, they must be able to r espond with agility in a geographically dispersed environment. The core for a vi rtual organization to increase the utilization rate of resources to the maxi mum and to make full use of the transient market opportunities lies in how to br ing the potential of information technology into play. Based on the philosophy o f agile manufacturing, this paper analyses the basic concepts and connotation of Virtual Organization Information systems(VOIS). VOIS is an information system composed of some independent information subsystems that are autonomous, collab orative and belong to umpty organizations respectively. VOIS support the operati on of virtual organization, and automate the information flow across organizatio nal boundaries. Such systems have capabilities as rapid construction, quick oper ation, and agile reengineering and swift adaptability. Differences between VOIS and traditional enterprise information systems are analyzed. On the basis of ana lyzing the structure of VOIS, an abstract hierarchical structure of VOIS is prop osed using object-oriented method. Reengineering ideology and methods of VOIS a re also explored in light of the three layers structure.

关键词： virtual organization information systems abstra ct hierarchical structure object- oriented method

AN INFEASIBLE-INTERIOR-POINT PREDICTOR-CORRECTOR ALGORITHM FOR THE SECOND-ORDER CONE PROGRAM

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Acta Mathematica Scientia 2008年第3期28卷 551-559页

作者：迟晓妮刘三阳 Department of Mathematical Sciences Xidian University

A globally convergent infeasible-interior-point predictor-corrector algorithm is presented for the second-order cone programming （SOCP） by using the Alizadeh- Haeberly-Overton （AHO） search direction. This algorithm does not require the feasibility of the initial points and iteration points. Under suitable assumptions, it is shown that the algorithm can find an -approximate solution of an SOCP in at most O（√n ln（ε0/ε）） iterations. The iteration-complexity bound of our algorithm is almost the same as the best known bound of feasible interior point algorithms for the SOCP.

关键词： Second-order cone programming, infeasible-interior-point algorithm, predictor-corrector algorithm global convergence

Strain coefficient measurement for the (100) uniaxial strain silicon by Raman spectroscopy

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Science China(Information Sciences) 2011年第8期54卷 1762-1768页

作者： DUAN Baoxing & YANG YinTang Key Laboratory of the Ministry of Education for Wide Band-Gap Semiconductor Materials and Devices,School of Microelectronics,xidian University,xi’an 710071,China Key Laboratory of the Ministry of Education for Wide Band-Gap Semiconductor Materials and Devices School of Microelectronics Xidian University Xi’an China

The lattice vibration model is established to express the crystalline silicon strain,based on which the strain coefficient b of -336.6 cm -1 is obtained for the uniaxial strain silicon with (100) crystalline *** Raman spectroscopy to measure single-axis crystalline silicon,the relationship between the screw rotation amount and the strain is advanced. By using a laser with a 648 nm wavelength,the Raman spectra frequency shift of 0.47 cm -1 is measured when the screw rotation amount is 1.5 *** strain coefficient b of -335.7 cm -1,obtained for the (100) uniaxial strain silicon,agrees with the result of the lattice vibration model.

关键词： Raman spectroscopy strain silicon lattice vibration

CLUSTERING PROPERTIES OF FUZZY KOHONEN'S SELF-ORGANIZING FEATURE MAPS

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Journal of Electronics(China) 1995年第2期12卷 124-133页

作者：彭磊胡征 Department of Information Engineering Xidian University Xi'an 710071

A new clustering algorithm called fuzzy self-organizing feature maps is introduced. It can process not only the exact digital inputs, but also the inexact or fuzzy non-digital inputs, such as natural language inputs. Simulation results show that the new algorithm is superior to original Kohonen’s algorithm in clustering performance and learning rate.

关键词： Self-organizing feature maps Fuzzy sets Membership measure Fuzziness mea-sure