双曲余弦-高斯光束的分数傅里叶变换特性研究

基于分数傅里叶变换(FRFT)与维格纳分布函数(WDF)旋转等效的性质．推导出了双曲余弦-高斯(ChG)光束在分数傅里叶变换面上光强分布和束宽的解析公式，研究了双曲余弦-高斯光束光强和束宽随分数傅里叶变换阶数的变化规律，分析了偏心参量对双曲余弦-高斯光束分数傅里叶变换特性的影响，并对数值计算结果进行了分析和讨论。结果表明，对给定偏心参量的双曲余弦-高斯光束，可以使其经过一定阶数的分数傅里叶变换来获得平顶光束。     

基于态函数的离散分数余弦倒谱变换在取证话音信息隐藏中的应用

 随着军事、安全等方面要求的日益增长,语音取证技术成为了语音信号处理和信息安全领域的热点和难点.本文提出了一种基于态函数的分数余弦倒谱变换,并将其应用到取证语音信息隐藏中,通过分析得到分数余弦倒谱变换的第3参数呈现一种独特的高频特性,从而提出了一种基于分数余弦倒谱变换的嵌入方法和过零率检测方法.实验仿真结果表明该方法具有一定的抗干扰能力,为分数余弦倒谱变换应用于取证语音信息隐藏提供了一种新的思路.     

分数阶傅立叶变换的多种定义形式及其光学实现系统分析

分数阶傅立叶变换是经典傅立叶变换的广义形式，它同时从时间域和频率域(或空间域)揭示信号特征．本文系统地分析了分数阶傅立叶变换三种定义形式及其所对应的光学实现系统的组成和原理，说明了光学信息处理系统实现分数阶傅立叶变换的有效性．     

利用Mobius求逆公式计算离散余弦变换

近年出现了一种利用数论中的Mobiue函数进行数字信号处理的傅里叶分析技术（通常称为算术博里叶变换）。这种方法在计算离散傅里叶变换时所需乘法次数仅为O(N)且非常适于VLSI处理．本文注意到利用这种技术计算离散余弦变换，只需计算两个博里叶系数中更为简单的偶分量an，从而使得计算N点离散余弦变换的乘法次数仅为N，计算结构相当简单．此外，计算机模拟表明，这种方法的误差与直接计算DCT缃比并不大，可以容忍。     

分数阶傅立叶变换的多种定义形式及其光学实现系统分析

分数阶傅立叶变换是经典傅立叶变换的广义形式,它同时从时间域和频率域(或空间域)揭示信号特征。本文系统地分析了分数阶傅立叶变换三种定义形式及其所对应的光学实现系统的组成和原理,说明了光学信息处理系统实现分数阶傅立叶变换的有效性.     

分数阶希尔伯特变换的复包络分析

分数Hilbert变换,也即传统的Hilbert变换由整数阶向分数阶的推广,由此其应用领域也得到了扩展,譬如在通信中的单边带调制解调系统,图像的边缘提取等领域中得到广泛的应用。首先,文中回顾了利用经典希尔伯特变换的正交性把经典的Hilbert变换的定义形式进行广义化后得到的分数阶Hilbert变换,并讨论了由分数阶Hilbert变换构造的两类复信号,最后讨论了这两类复信号的包络提取并且给出了具体的实例。     

图像处理中的正交变换探讨

正交变换是一类非常重要的变换,其具有使变换前后图像能量保持不变的特性.图像的正交变换是图像处理技术的重要工具,被广泛地运用于图像特征提取、图像增强、图像复原、图像压缩和图像识别等领域.首先,论述了正交变换的定义及编码原理;其次,对正交变换中的傅立时变换和离散余弦变换的基本概念、性质、算法以及在图像处理中的应用等进行了详细的叙述;最后,利用Madab和C++编程,实现了快速离散傅立叶变换和离散余弦变换,并对两种变换结果的优劣作了全面的比较.     

基于余弦调制滤波器组的一种高效实现

本文给出了基于余弦调制的ＦＩＲ分析／综合滤波器组的一种高铲实现结构，其分析节和综合节分别由多相结构和离散正余弦变换网络组成；去除了由ＤＦＴ网络的计算冗余，与文献」３「相比，有效减少了总的计算量，进一步提高计算效率，具有较大的理论意义和实用价值。计算机仿真结果证明了本实现结构。     

基于基本光学单元的分数傅里叶变换算法

提出两种分数傅里叶变换数值计算新方法。本文用分数傅里叶变换描述信息在光学系统中的传输过程 ,分别基于分数傅里叶变换与菲涅尔变换之间联系和基于基本光学单元 (薄透镜及其组合 )实现分数傅里叶变换。该算法与光传输物理过程有着直观的联系 ,计算时光学系统的焦距、距离等参数可调。避免了传统算法中“变换核”等复杂计算 ,便于计算复杂光路和缩短计算时间。以三种飞机 (及字符 )光学模式识别实验为例 ,给出了空域 -频域变换混合光路的计算流程与结果     

基于离散分数阶角变换与关联混沌映射的双图像加密算法

为了实现对两个明文进行同步安全加密,提出了联合离散多参数分数阶角变换与低维映射的双图像加密算法.基于离散余弦变换(DCT)与Zigzag扫描建立了复合系数矩阵模型,通过反离散余弦变换(IDCT)将两个明文融合成一幅图像;通过耦合Logistic映射,利用明文像素均值与外部密钥计算其初始条件值,并迭代该耦合映射,输出2个随机序列;分别对这2个随机序列进行排序,设计位置数组扰乱机制对复合明文进行置乱;将置乱密文分解为2个新分量,利用Logistic映射与初始明文分别生成混沌随机与调制相位掩码,将2个新分量融合成临时密文;基于离散分数角变换构建了新的2D多参数分数阶角变换,设计加密模型并完成图像加密.结果表明,与已有双图像加密机制相比所提算法的保密性更佳,有更好的抗明文攻击特性.     

Technology innovation and process integrations for sub-100nm gate patterning

This paper presents a brief overview of the Applied Centura(R)DPS(R)system,configured with silicon etch DPS Ⅱ chamber, with emphasis on discussing tuning capability for CD uniformity control. It also presents the studies of etch process chemistry and film integration impact for an overall successful gate patterning development. Discussions will focus on resolutions to key issues, such as CD uniformity, line-edge roughness, and multilayer film etching integration.     

White organic light-emitting devices based on fac tris（2- phenylpyridine） iridium sensitized 5,6,11,12-tetraphenylnap -hthacene

We have fabricated the white organic light-emitting devices （WOLEDs） based on 4,4＇ -bis（2,2 -diphenyl vinyl）-1,1＇ - biphenyl （DPVBi） and phosphorescence sensitized 5,6,11,12,-tetraphenylnaphthacene （rubrene）. The device structure is ITO/2T-NATA （20 nm）/NPBX （20 nm）/CBP： x%Ir（ppy）3：0.5% rubrene （8 nm）/NPBX （5 nm）/DPVBi （30 nm）/Alq（30 nm）/LiF（0.5 nm）/A1. In the devices, DPVBi acts as a blue light-emitting layer, the rubrene is sensitized by a phosphorescent material, fac tris （2-phenylpyridine） iridium [Ir（ppy）3], acts as a yellow light-emitting layer, and N,N＇ -bis- （1-naphthyl）- N,N＇ -diphenyl -1, 1＇ -biphenyl-4,4＇ -diamine （NPBX） acts as a hole transporting and exciton blocker layer, respectively. When the concentration of Ir （PPY）3 is 6wt%, the maximum luminance is 24960 cd/m^2 at an applied voltage of 15 V, and the maximum luminous efficiency is 5.17 cd/A at an applied voltage of 8 V.     

Complete approach to automatic identification and subpixel center location for ellipse feature

To meet the need of automatic image features extraction with high precision in visual inspection, a complete approach to automatic identification and sub-pixel center location for similar-ellipse feature is proposed. In the method, the feature area is identified automatically based on the edge attribute, and the sub-pixel center location is accomplished with the leastsquare algorithm. It shows that the method is valid, practical, and has high precision by experiment. Meanwhile this method can meet the need of instrumentation of visual inspection because of easy realization and without man-machine interaction.     

小角度扩展相关性近似算法分析

本论文提出一种在多天线MIMO信道相关性建模中小角度扩展近似理论算法,并应用于分析MIMO系统性能。分析中分别对三种不同角能量分布情况下的空间相关性研发快速近似计算法,并同时提出双模(Bi-Modal)角能量分布情况下的近似运算。通过分析这些新方法的近似效率,可以得到计算简单、复杂度低、而且符合实际的MIMO相关信道矩阵,对系统级的快速高效计算法的研究和系统级的评估以及误差分析具有重要的意义。     

A Versatile Mixed-Signal Pin Approach for Cost-Effective Test of Automotive ICs

Integrated circuits (ICs) intended for increasingly sophisticated automotive applications bring unique test demands. Advanced ICs for applications such as highly integrated automatic braking system (ABS) and airbag controllers combine high voltage digital channels, significant VI demands and precise timing capability. Along with continued missioncritical reliability concerns, the trend toward higher voltage operation and increased device integration requires specialized test capabilities able to extend across the wide operating ranges found in automotive applications. Among these capabilities, automotive test requirements increasingly dictate a need for a cost-effective versatile mixed-signal pin electronics with very high data rates reaching up to 50MHz with a voltage swing of-2 V to +28 V.     

Optical vibration and deviation measurement of rotating machine parts

It is of interest to get appropriate information about the dynamic behaviour of rotating machinery parts in service. This paper presents an approach of optical vibration and deviation measurement of such parts. Essential of this method is an image derotator combined with a high speed camera or a laser doppler vibrometer （LDV）.     

INTEGRATION OF OPTICAL AND WIRELESS NETWORKS

正For a long time,optical and wireless systems/net-works are developed in separate communities witha few attempts for in-depth convergence.In fact,it prom-ises many advantages to combine the optical and wire-less technologies in the levels of systems and networks.Recently,both academia and industry have made manyefforts to enter a new phase of development to take op-tical and wireless systems as fully integrated networks.To provide high bandwidth and reliable service for bothfixed and mobile users,a well-designed network must     

社长序言（英文）

正Happy New Year!As we step into a new year,we take a look back at the key feature topics covered in China Communications over the past 12 months and set out our expecta-     

云计算专题（英文）

正Cloud computing is a novel computing paradigm that utilizes remote cloud resources to achieve a high-performance computation.Cloud provides infrastructure,platform and software as different on-demand services.China has made remarkable progress in cloudbased products and operating system technology.The government,enterprises and research institutions are all active in the development of cloud computing-related projects.Despite the progress,many important problems     

Call for Papers—Feature Topic,Vol.12,No.3,2015

正Smart Grid Communications The electric power industry is undergoing profound changes as the industry aims to capture the promise of a smart grid for a sustainable energy future.Enabled by the advanced sensing devices such as Phasor Measurement Units(PMUs),increasingly powerful