EXTENDED HELMHOLTZ THEOREM AND ITS APPLICATION IN ELECTROMAGNETIC THEORY

It is proved that in a regular boundary system of rectangular,cylindrical or sphericalcoordinate,an arbitrary vector function can be separated into three orthogonal parameters:TEmodel field,TM model field and irrotational field.Each of these components can be determinedfully by a scalar function.On the basis of this theorem,the completeness of vector wave functionsystem{L,M,and N}is proved also.Thus it is explained that a vector function space can beprojected into three uncrossed subspaces not only in Euclidean space but also in the subspace ofvector wave function space.     

Extended complex RBF and its application to M-QAM in presence ofco-channel interference

An extended complex radial basis function (CRBF) network is proposed for the equalisation of a 4-QAM digital communication channel in the presence of additive white Gaussian noise and co-channel interference. The proposed model has complex valued regression weights in the output layer, and the hidden unit is defined by a real valued Gaussian formula with Mahalanobis distance. It is shown by simulation that the proposed structure gives reduced computational complexity without leading to a degradation in performance     

Rate-distortion theory and application

The theoretical minimum channel capacity required to transmit a given source at a given average distortion level is discussed. The limitations and applications of the theory are reviewed with particular emphasis on the use of the results for guiding practical system design and for bounding system performance. Applications are oriented toward video sources.     

Extended permutation filters and their application to edge enhancement.

Extended permutation (EP) filters are defined and analyzed. In particular, we focus on extended permutation rank selection (EPRS) filters. These filters are constrained to output an order statistic from an extended observation vector. This extended vector includes N observation samples and K statistics that are functions of the observation samples. The rank permutations from selected samples in this extended observation vector are used as the basis for selecting an order statistic output. We show that by including the sample mean in the extended observation vector, the filters exhibit excellent edge enhancement properties. We also show that several previously defined classes of rank-order-based edge enhancers (CS, LUM, and WMMR sharpeners) can be formulated as subclasses of EPRS filters. These sharpening subclasses are in addition to the smoothing subclasses, which include rank conditioned rank selection, permutation stack, and weighted order statistic filters. Thus, this novel class of filters provides a broad framework within which many rank-order-based smoothers and edge enhancers can be unified. Edge enhancement properties are developed and an L(n) norm EPRS filter optimization procedure is presented. Finally, extensive computer simulation results are presented, comparing the performance of EPRS and other sharpening filters in edge enhancement applications.     

A theory of complex open resonators in the form of cavity chain

Journal of Infrared, Millimeter, and Terahertz Waves - The previous theory ((2,6)) of microwave open resonators has been improved, which can be applicable not only to simple cavities, but also to...     

ENUM技术原理及其应用场景

基于E.164号码的用户标识是目前普遍接受的用户标识方式,如何将E.164号码转换成域名和IP地址,以便于IP网络进行寻址和路由,ENUM技术是近年来影响较大的方案之一.文章就ENUM的技术原理进行了简单的介绍,并分析了其在IMS、多媒体消息路由以及软交换等多种场景下的典型应用.     

扩散光谱的原理和应用

详细介绍了扩散光谱(DWS)技术的基本原理及其常见的实验方法.对近年来发展起来的微流变学、时间分辨扩散光谱等技术进行了简要介绍,总结了DWS在粒度分析、微流变学、医学检测、电磁流变体研究中的应用情况.     

The surface Laplacian of the potential: theory and application

The use of the surface Laplacian of the potential (L_s) in bioelectricity is discussed. Different estimates of L_s, in particular the field measured by coaxial electrodes, are compared to that of the true Laplacian. A method to compute L_s on the surface of an inhomogeneous volume conductor of arbitrary shape resulting from assumed electrical sources is introduced. In two applications the sensitivity of the body surface Laplacian is compared to that of body surface potentials. This comparison is carried out for dipolar sources within the human brain as well as for distributed sources within the heart     

粗糙集理论及其应用研究

粗糙集理论是一种处理不确定和不完全数据的强有力数学工具,其主要思想是在保持分类能力不变的前提下,通过数据约简得出问题的决策或分类规则.目前,粗糙集理论已成功地应用于机器学习、决策分析、过程控制、数据挖掘等领域,是当前人工智能领域研究热点之一.现介绍了粗糙集理论及其应用的国内外研究现状,总结了主要研究方法,最后指出了粗糙集理论及其应用所面临的主要问题.     

滤波多音调制技术的应用

文章详细介绍了滤波多音调制(FMT)这种基于滤波器组调制的新兴多载波调制技术,并将其与现有的其他多载波传输技术(如OFDM)作了对比,指出了有待研究的有关课题,最后对FMT在宽带无线数据传输中的应用作了初步展望。     

复射线理论应用于天线一体化设计

分析自由空间天线辐射特性的方法已十分成熟,如口径场积分法、平面波谱积分法等,它们大都是行之有效的,但要求对天线及天线罩进行一体化分析时,现有的经典方法往往不能迅速而准确地给出解答,如果用复射线理论这一新方法则可以对某些问题圆满地给出结果.根据复射线理论,利用复源点远场具有的高斯波束特性,无论是在远区或是近轴区域内,复源点场和高斯函数有很接近的相同分布,理论上论证了对于具有高斯波束分布的口径场可以用复源点场来近似模拟.     

论气相色谱法在环境监测中的应用

在四十余年中,由于气相色谱技术在高效分离与检测方式等多方面不断发展,使其应用领域更加广泛,当前已经成为石油化工、自然环境保护、临床等领域中进行分析、分离的一种必要的方式。本文概述了气相色谱法发展、原理与系统组成以及在环境监测中测定土壤中残留农药和有毒、有害气体方面的使用状况与进展,并进行深入探索。     

复杂网络社团结构理论在电力调度网中的应用

随着电力调度网规模的不断扩大,电力分级调度网络的划分日益成为复杂难解的问题。本文以复杂网络理论为基础,构建电力调度网的复杂网络模型,通过计算网络节点介数,挖掘网络社团结构,进行电力分级调度拓扑结构构建,并采用了一个模拟的电力调度网进行实验验证,划分准确率达到100％,实验结果说明该方法是有效、可行的。     

Vector control for induction machine on the application of optimalcontrol theory

An approach for constructing a field-oriented control system using the state-space method is proposed. The field-oriented control system can be realized by coinciding the synchronously rotating reference frame with the axes of the secondary flux linkage reference frame and by simultaneously but independently adjusting the three control inputs. A control-system synthesis method that achieves speed control, field-oriented control, and constant flux control simultaneously is presented. The control system has a full-state feedback structure and is synthesized by applying a multi-input and multi-output optimal regulator theory. The excellent robustness of the constructed system results in zero steady-state errors for changes in parameters such as rotor resistance. The validity of the control scheme is verified by simulation studies. Results are presented for a field-oriented induction motor driven by a PWM (pulse-width modulation) inverter     

Towards a theory of application in systems science

The actual utilization of systems science, especially social systems engineering, has not measured up to the plethora of theories and examples of potential applications in the literature. To begin developing a theory of application in systems science, one may consider modeling the systems scientist as a system or consider nonsystems approaches that would include the political influence, feelings, aesthetic, and religious dimensions of both the analyst and the user. The essential ideas of this process are presented in summary form.     

An application of coding theory to document retrieval

In this paper, methods for document retrieval are derived from algebraic coding theory. It is shown that these methods are efficient in information representation and that the amount of computation required in implementation is quite reasonable.     

粗糙集理论及其在管理决策中的应用浅析

在管理决策过程中，人们经常接受到这样的信息，这些信息不能用精确的集合表示，从它们的特征上看，这类信息是粗糙的，不完备的。粗糙集理论是分析和处理不完备信息的有效工具，现就粗糙集理论本身的发展和其在管理学领域的最新应用进行分析和介绍，并提出在应用过程中存在的问题。