Providing buyer feedback on digital switch field performance

Argues that buyers of digital switching equipment can and should play a more active role in providing feedback on deployed equipment's field performance. Such feedback is even more important for making continuous reliability gains in the divested environment and as new technologies and functionality are rapidly deployed. To understand what role a buyer might play, the authors review various factors leading to field performance problems and their short- and long-term consequences. A reliability review forum process for providing timely and accurate performance feedback is then described. This type of process has been successful in assuring both rapid corrective actions and long-term reliability gains     

Carbon Nanotube Field-Effect Transistors for High-Performance Digital Circuits—Transient Analysis, Parasitics, and Scalability

Silicon-based CMOS is the dominant technology choice for high-performance digital circuits. While silicon technology continues to scale, researchers are investigating other novel materials, structures, and devices to introduce into future technology generations, if necessary, to extend Moore's law. Carbon nanotubes (CNTs) have been explored as a possibility due to their excellent carrier mobility. The authors studied and compared different carbon-nanotube-based field-effect transistors (CNFETs) including Schottky-barrier (SB) CNFETs, MOS CNFETs, and state-of-the-art Si MOSFETs systematically from a circuit/system design perspective. Parasitics play a major role in the performance of CNT-based circuits. The data in this paper show that CNFET design's performance is limited by the gate overlap capacitance and the quality of nanocontacts to these promising transistors. Transient analysis of high-performing single-tube SB CNFET transistors and circuits revealed that 1-1.5 nm is the optimum CNT diameter resulting in best power-performance tradeoff for high-speed digital applications. The authors determined optimal spacing and layout of CNT arrays, an architecture that is most likely required for driving capacitive loads and interconnects in digital applications. CNTs have an intrinsic capability to improve performance, but many serious technological and experimental challenges remain that require more research to harvest their potential     

速率陀螺稳定电视导引头平台数字控制器设计

采用连续校正网络的等效数字控制器设计方法设计数字校正网络,并选用高速数字信号处理器（DSP）构成稳定回路的数字控制系统。用MATLAB软件对系统进行计算机仿真,仿真结果表明,所设计的数字控制系统能够满足指标要求,从而证明这种设计方法的可行性。     

淮阴区城区三网融合设计改造技术方案

根据国务院关于三网融合的精神要求,结合淮阴区网络的实际情况,重点介绍了为满足三网融合要求而建设改造的新一代数字综合网组网技术方案,设计全区统一的数字网络平台,为最终顺利过渡到下一代广播电视网(NGB)奠定坚实的基础。     

Mixed-signal design of a fully parallel fuzzy processor

The authors present a novel architecture for implementing general-purpose fuzzy chips which allows fully-parallel rule processing employing a reduced number of mixed-signal computing blocks and minimum-sized digital memories. The resulting fuzzy processor can interact directly with continuous sensors and actuators and the subsequent digital processing system     

A 27-MHz digital-to-analog video processor

The authors describe a circuit intended for the restitution of a digital video signal into its analog red, green, and blue components. Sampling parameters according to CCIR recommendation 601 have been adopted for the digital interface. The circuit consists mainly of a complex digital processing part and three digital-to-analog converters. All of these functions have been implemented in a 38-mm² CMOS chip. The design goal was achieved by the development of an efficient 2-μm CMOS technology dedicated to analog and digital applications     

Data compression systems for home-use digital video recording

The authors focus on image data compression techniques for digital recording. Image coding for storage equipment covers a large variety of systems because the applications differ considerably in nature. Video coding systems suitable for digital TV and HDTV recording and digital electronic still picture storage are considered. In addition, attention is paid to picture coding for interactive systems, such as the compact-disc interactive system. The relation between the recording system boundary conditions and the applied coding techniques is outlined. The main emphasis is on picture coding techniques for digital consumer recording     

Microwave photonic vector modulator for high-speed wireless digitalcommunications

The authors present the design, realization, and experimental results of a microwave/photonic circuit suitable for high-speed direct digital modulation of microwave signals. The modulator employs a combination of microwave, photonic, and digital techniques to produce a discrete phase and amplitude (i.e., vector) modulated carrier signal. The proof-of-concept demonstration presented in this paper was performed using a carrier frequency of 1 GHz and supports BPSK, QPSK, and 16-QAM. The authors also discuss ways to modify the modulator to simultaneously achieve data rates on the order of several hundreds of Mbs and wideband frequency hopping     

LSIs for digital signal processing

The authors describe high-performance CMOS LSIs for digital signal-processing (DSP) technology, such as digital filter, fast Fourier transform (FFT), discrete Fourier transform (DFT), and digital phase-locked loop (DPLL), for communication use. Device design for high-speed and low-power CMOS is described and its feasibility is shown as characteristics of propagation delay time and power delay product.     

Digital optical phase control in ridge-waveguide phase modulators

The authors report a digital optical phase modulation concept based on depletion-edge-translation p-n junction GaAs/AlGaAs ridge-waveguide modulators. Digital modulation is achieved by integrating in series several discrete waveguide modulators with lengths related by successive factors of two. To illustrate the concept, the authors fabricated and demonstrated a three-bit digital phase modulator with 45° resolution. This structure represents the first photonic integrated circuit that performs direct digital-electronic to analog-optical conversion     

Description of FIR digital filters in the form of parallelconnection of linear phase FIRs

The authors aim to show that FIR digital filters can be described in the form of parallel connection of linear phase FIR digital filters. This representation method may be applicable to FIR digital filter design problems, reducing it to linear phase FIR digital filter design problems     

文字数字信息的噪声处理

本文针对手写文字转换成二值字符图形后出现的噪声现象和识别方法对二值字符图形的要求,提出了一种处理字符噪声的算法。文中介绍了算法的软硬件实现,给出了实验结果。文中提出的算法不限于手写文字场合,凡属文中类型的噪声,都可用本算法处理。     

Authenticated encryption schemes with low communication costs

A possible application of the Nyberg-Rueppel digital signature scheme is for authenticated encryption. The authors present schemes in which the communication costs are low in comparison to the basic scheme and which can be constructed from the Nyberg-Rueppel digital signature scheme     

数字电影文件如何在Authorware中正常播放

将不同格式的数字电影文件插入到用Authorware制作的程序中并完成播放。通过对数字电影格式的了解及对Authorware本身功能的分析,提出两种新的且操作简单的方法：一种是对有关文件进行格式转化后直接通过“数字电影”图标引入;另一种是通过Authorware菜单栏中的“插入”／TabuleiroXtras／DirectMediaXtra。不同格式的数字电影文件在Authoreware中正常的播放。数字电影文件的应用,提高了作品内容的丰富性。     

A condition for digital points removal

Removal operations play a crucial role in most algorithms which transform digital figures into stick-like ones. In this note, digital points that are candidates to deletion are examined and a necessary and sufficient condition for their removal is given.     

浅谈网络电视对数字电视的影响

阐述了我国网络电视和数字电视的发展现状、遭遇的困难等问题,从政策、市场等角度进行了分析,指出网络电视与数字电视是互相依存互相促进的发展关系,二者并存将是一个长期的发展过程。对我国三网融合政策下的数字电视发展指明方向,具有积极的现实意义。     

唐山有线数字电视平台的组成及应用

以唐山有线数字电视网络体系结构设计为例,从数字电视前端播控平台、市区传输网络、机顶盒接收三方面入手,阐述了数字电视系统的传输工作流程以及部分网络设备的工作原理。     

三网融合背景下数字图书馆信息服务

三网融合背景下，手机、数字电视等新媒体的发展，拓展了数字图书馆的服务空间，给图书馆发展带来新的机遇，数字图书馆利用数字电视与移动通信作为平台开展服务已经高校图书馆服务重要手段，结合案例分析“三网融合”在我国数字图书馆界的引用。     

Decorrelation in interferometric radar echoes

A radar interferometric technique for topographic mapping of surfaces, implemented utilizing a single synthetic aperture radar (SAR) system in a nearly repeating orbit, is discussed. The authors characterize the various sources contributing to the echo correlation statistics, and isolate the term which most closely describes surficial change. They then examine the application of this approach to topographic mapping of vegetated surfaces which may be expected to possess varying backscatter over time. It is found that there is decorrelation increasing with time but that digital terrain model generation remains feasible. The authors present such a map of a forested area in Oregon which also includes some nearly unvegetated lava flows. Such a technique could provide a global digital terrain map     

Biorthogonal partners and applications

Two digital filters H(z) and F(z) are said to be biorthogonal partners of each other if their cascade H(z)F(z) satisfies the Nyquist or zero-crossing property. Biorthogonal partners arise in many different contexts such as filterbank theory, exact and least squares digital interpolation, and multiresolution theory. They also play a central role in the theory of equalization, especially, fractionally spaced equalizers in digital communications. We first develop several theoretical properties of biorthogonal partners. We also develop conditions for the existence of biorthogonal partners and FIR biorthogonal pairs and establish the connections to the Riesz basis property. We then explain how these results play a role in many of the above-mentioned applications