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51.
针对有线电视系统工程建设的特点,依照《招标投标法》的规定和程序,对有线电视系统工程招标的种类、招标方式、招标工程必备的条件、标底的编制及审定、开标、评标和中标的原则进行详细介绍,对招标文件的编制进行具体说明。 相似文献
52.
在讨论包装技术高级技能人才概念的基础上,从培养的途径、培养的方式等方面进行了详细的分析与探讨. 相似文献
53.
In this paper, the moving least-squares differential quadrature (MLSDQ) method is employed for free vibration of thick antisymmetric laminates based on the first-order shear deformation theory. The generalized displacements of the laminates are independently approximated with the centered moving least-squares (MLS) technique within each domain of influence. The MLS nodal shape functions and their partial derivatives are computed quickly through back-substitutions after only one LU decomposition. Subsequently, the weighting coefficients in the MLSDQ discretization are determined with the nodal partial derivatives of the MLS shape functions. The MLSDQ method combines the merits of both the differential quadrature and meshless methods which can be conveniently applied to complex domains and irregular discretizations without loss of implementation efficiency and numerical accuracy. The natural frequencies of the laminates with various edge conditions, ply angles, and shapes are calculated and compared with the existing solutions to study the numerical accuracy and stability of the MLSDQ method. Effects of support size, order of completeness of basis functions, and node irregularity on the numerical accuracy are investigated in detail. 相似文献
54.
The Two-Dimensional Clifford-Fourier Transform 总被引:1,自引:0,他引:1
Fred Brackx Nele De Schepper Frank Sommen 《Journal of Mathematical Imaging and Vision》2006,26(1-2):5-18
Recently several generalizations to higher dimension of the Fourier transform using Clifford algebra have been introduced,
including the Clifford-Fourier transform by the authors, defined as an operator exponential with a Clifford algebra-valued
kernel.
In this paper an overview is given of all these generalizations and an in depth study of the two-dimensional Clifford-Fourier
transform of the authors is presented. In this special two-dimensional case a closed form for the integral kernel may be obtained,
leading to further properties, both in the L
1 and in the L
2 context. Furthermore, based on this Clifford-Fourier transform Clifford-Gabor filters are introduced.
AMS subject classification numbers: 42B10, 30G35
Fred Brackx received a diploma degree in mathematics from Ghent University, Belgium, in 1970 and a Ph.D. degree in mathematics from the
same university in 1973. Since 1984 he is professor for mathematical analysis at Ghent University and currently he is leading
the Clifford Research Group. His main interests are function theory and functional analysis for functions with values in quaternion
and Clifford algebras. The research covers Clifford distributions, generalized Fourier, Radon and Hilbert transforms, orthogonal
polynomials and multi-dimensional wavelets.
Nele De Schepper received a diploma degree in mathematics from Ghent University, Belgium, in 2001. Since then she holds an assistantship at
the Department of Mathematical Analysis of Ghent University and is a member of the Clifford Research Group. Her main interests
are function theory and functional analysis for functions with values in Clifford algebras. The research covers generalized
Fourier transforms, orthogonal polynomials and multi-dimensional wavelets.
Frank Sommen received a diploma degree in mathematics from Ghent University, Belgium, in 1978, a Ph.D. degree in mathematics from the
same university in 1980, and a habilitation degree in mathematical analysis in 1984. From 1978 until 1999 he was at the National
Fund for Scientific Research (Flanders). Since 2000 he holds a Research professorship at Ghent University. His main interests
are function theory and functional analysis for functions with values in quaternion and Clifford algebras. The research covers
Clifford distributions, generalized Fourier, Radon and Hilbert transforms, orthogonal polynomials and multi-dimensional wavelets,
algebraic analysis, hyperfunctions and radial algebra. 相似文献
55.
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57.
The focus of this paper lies in the practical aspects of voice over IP communication. VoIP configurations in the H.323 standard will be presented briefly. Following that, the fundamental protocol procedure of H.323 communication will be briefly explained. A further part of the paper will address the subject QoS (quality of service), and present the common measurement methods used in QoS. Results gained from experiments conducted in a VoIP environment will then follow. The investigations concentrate primarily on the load behavior of voice packets in relation to important parameters of this service. The results obtained are presented and evaluated in diagrams. The paper concludes with a summary. 相似文献
58.
电力系统谐波检测的现状与发展 总被引:7,自引:0,他引:7
准确、实时地对电力系统谐波进行检测有着重要的意义。本文根据电力系统谐波测量的基本方法,对近年来电力系统谐波检测的新方法进行了分析和评述。最后对电力系统的谐波测量进行了总结并提出了看法。 相似文献
59.
基于扩展分形和CFAR特征融合的SAR图像目标识别 总被引:3,自引:0,他引:3
研究了多信息融合技术在SAR图像目标识别中的应用。将扩展分形特征(Extended Fractal)与双参数恒虚警特征(Double Parameter CFAR)形成的多信息进行融合处理。运用Dempster-Shafer证据理论,在决策层对SAR图像中的像素进行识别分类。实验结果表明通过融合对像素分类的准确性明显好于单特征的检测结果,减少了虚警概率,提高了系统的识别能力。 相似文献
60.