Packet Scheduling with QoS Differentiation

This article focuses on the Quality of Service (QoS) achieved by packet scheduling. A packet scheduling algorithm, which can differentiate the QoS among user and service classes, is presented. The algorithm can be tuned from signal to interference ratio (C/I) based scheduling to Round Robin and beyond. Thus, an operator can choose between optimizing the spectral efficiency or giving a fair QoS distribution among the users within a user and traffic class. By combining the two effects, different strategies can be used for different user and service classes. Simulation results for the downlink shared channel (DSCH) are presented and implementation issues are also discussed.     

Differentiation of discrete multidimensional signals

We describe the design of finite-size linear-phase separable kernels for differentiation of discrete multidimensional signals. The problem is formulated as an optimization of the rotation-invariance of the gradient operator, which results in a simultaneous constraint on a set of one-dimensional low-pass prefilter and differentiator filters up to the desired order. We also develop extensions of this formulation to both higher dimensions and higher order directional derivatives. We develop a numerical procedure for optimizing the constraint, and demonstrate its use in constructing a set of example filters. The resulting filters are significantly more accurate than those commonly used in the image and multidimensional signal processing literature.     

WCDMA差异化服务探讨

通过对WCDMA网络中各种业务特性和用户需求的分析,指出了如何在WCDMA中采用QoS机制降低运营成本并提高终端用户的满意度,给出了差异化QoS的实现方案。     

浮游植物荧光特征提取及识别测定技术

为了区分和识别不同门和属的浮游植物,以coiflet2小波函数(coif2)为基函数对4个门类9个属的12种浮游植物的三维荧光光谱进行分解,选取第三层尺度分量作为浮游植物识别特征谱.不同门类和属(种)的浮游植物的特征谱具有明显的特征差异.Bayes判别分析结果表明,此类特征谱对浮游植物在门类层次上的总分类正确率可达99.0%,属层次上的总分类正确率可达97.4%.以聚类分析法确立浮游植物特征谱的标准谱库,以此为基础,利用线性回归法(非负最小二乘法解析)建立浮游植物荧光识别测定技术.该技术对单种浮游植物样品在门类及属层次上的识别正确率均大于98.0%,当加入10%或20%的随机噪声时,在门类及属的层次上的识别正确率分别大于98.0%和85.0%;对浮游植物混合样品中的优势种在门及属的层次上的识别正确率均为100%.     

实现图像光学微分的方法研究

光学图像微分（边缘增强）是光学信息处理中突出信息的一种重要方法。本文介绍了全息复合光栅和光学子波变换在实现图像边缘增强中的应用,并进行了实验研究和原理分析。实验结果表明这两种方法都是实现图像边缘增强的有效方法,相比较而言,光学子波变换更为快速和实用。     

A QRS Preprocessor Based on Digital Differentiation

Digital preprocessors can ease the increasing data collection demands placed on real-time computers in patient monitoring. This paper describes a preprocessor that detects in real time an electrocardiogram QRS complex and computes the R-R interval. Detection is performed using multiple digital differentiation, which is encouraging as an ultrareliable means for locating the QRS. Inherent in the technique is a dependable control that can automatically compensate for signal-level variations. Clinical data demonstrate that detection is insensitive to low- and high-frequency noise, from baseline drift to muscle artifact and cautery bursts. The device can be connected directly to a patient, whose safety is guaranteed by optoelectronic isolation and interelectrode current limiting. Preprocessor operation has been human-engineered to a simple on/off procedure.     

Digital Low-Pass Differentiation for Biological Signal Processing

Digital low-pass differentiation is often required in processing various biological or biomechanical data. However, both the nature of biological signals and the use of micro-or minicomputers in such applications imply the need for simple, low-order, and fast differentiation methods, rather than sophisticated high-order algorithms. Responding to this need, we investigate here the low-pass first- and second-order digital differentiation from both theoretical and practical points of view, in order to achieve good and simple algorithms. In contrast with most of the research works previously done in this field, whose main aim was to achieve better accuracy even in the cost of using quite high-order algorithms, we restrict ourselves in this study only to low orders, being interested not only in the accuracy achieved, but also in the simplicity of the algorithm. After discussing the theoretical considerations concerning our optimum low-pass differentiation filters, we present our simple low-order filters and show them to be not only very convenient for use, but also almost optimum.     

中国IC设计公司的机会:创新和差异化

编者按:最近中国IC设计产业受到"汉芯事件"的影响,可能总体受到一定冲击,使本已经比较艰难的IC设计有些雪上加霜的味道.但由于巨大的消费市场拉动,中国IC设计产业的成长将是不可阻挡的趋势.Synopsys公司董事长兼首席执行官Aart de Geus博士访华,这里把他对产业发展的趋势和中国本地设计公司应该做的取舍等见解与大家分享.     

地空红外探测距离推算方法探讨

由红外探测系统理想作用距离方程出发,详细分析了红外目标辐射强度、天空背景辐射强度、大气透过率等因素对地空红外探测距离的影响,给出了探测距离的推算公式.     

一种LUT型胚胎电子阵列的功能分化方法

针对LUT型胚胎电子阵列功能分化方法的不足,提出了一种新型的LUT型胚胎电子阵列功能分化方法,根据目标电路的功能描述,通过前端综合、逻辑优化、逻辑映射、打包等操作,将目标电路转换为电子细胞为基本节点的电路形式,通过物理映射、基因库生成,将电路映射到阵列上,确定阵列中每个细胞的功能、连接,最终生成目标电路的基因库并确定每个细胞的表达基因,完成胚胎电子阵列的功能分化.该方法无需对计算过程中每一代电路进行功能评估,运算量小,计算速度快,为基于LUT型胚胎电子阵列的自修复电路应用提供了设计方法.最后,使用一个算例阐述了功能分化过程,并通过多个电路验证了该方法的分化速度.     

发送端自感知的概率粒度的数据包丢失原因甄别机制

We start this paper by answering the questions: What requirements should a good Loss Differentiation Mechanism (LD) for 802.11 networks in IoT meet? Do the existing LDs work well in 802.11 networks when moving towards IoT? Then we present the four properties that a LD used in IoT should own and the two-folded factors that we should consider when designing such a LD. Thereby, a novel LD is proposed utilizing the back-off frozen event to reveal collision probability. Our mechanism works efficiently with standard 802.11; only practical statistics information is needed. In addition, our mechanism can be done solely by the sender without introducing extra signaling overhead. Extensive simulations show that our mechanism can be applicable to different scenarios in 802.11 WLANs.     

电子元器件质量等级辨析

分析了电子元器件质量保证等级和可靠性预计质量等级,对其概念、规范、标识等内容进行辨析,并对易混淆的部分举例进行说明,为产品研制中规范使用质量等级应用和管理元器件提供帮助。     

Non-Cooperative Games for Service Differentiation in CDMA Systems

In this paper, we address the problem of user-class based service differentiation in CDMA networks. Users are categorized into three classes who get differentiated services based on their expected quality of service (QoS) from the service provider and the price they are willing to pay. We adopt a game theoretic approach for allocating resources through a two-step process. During a service admission, resource distribution is determined for each class. Then, the resource allocated to each class is distributed among the active users in that class. We devise a utility function for the providers which considers the expected revenue and the probability of users leaving their service provider if they are not satisfied with the service. Our model demonstrates how power can be controlled in a CDMA network to differentiate the service quality. Also, we show the impact of admitting high paying users on other users. Mainak Chatterjee received his Ph.D. from the department of Computer Science and Engineering at The University of Texas at Arlington in 2002. Prior to that, he completed his B.Sc. with Physics (Hons) from the University of Calcutta in 1994 and M.E. in Electrical Communication Engineering from the Indian Institute of Science, Bangalore, in 1998. He is currently an Assistant Professor in the department of Electrical and Computer Engineering at the University of Central Florida. His research interests include economic issues in wireless networks, applied game theory, resource management and quality-of-service provisioning, ad hoc and sensor networks, CDMA data networking, and link layer protocols. He serves on the executive and technical program committee of several international conferences. Haitao Lin received the BE degree in radio engineering from Southeast University, Nanjing, China, in 1996, the MS degree in computer applications from the Beijing University of Posts and Telecommunications, Beijing, China, in 2000, and Ph.D. in Computer Science and Engineering from The University of Texas at Arlington in 2004. He is currently with Converged Multimedia Services System Engineering at Nortel, Richardson, Texas. His research interests include wireless network performance evaluation and enhancement, wireless link adaptation, wireless network resource management, and applied game theory. Sajal K. Das received B.S. degree in 1983 from Calcutta University, M.S. degree in 1984 from Indian Institute of Science, Bangalore, and Ph.D. degree in 1988 from University of Central Florida, Orlando, all in Computer Science. He is currently a Professor of Computer Science and Engineering and also the Founding Director of the Center for Research in Wireless Mobility and Networking (CReWMaN) at the University of Texas at Arlington (UTA). Prior to 1999, he was a professor of Computer Science at the University of North Texas (UNT), Denton where he founded the Center for Research in Wireless Computing (CReW) in 1997, and also served as the Director of the Center for Research in Parallel and Distributed Computing (CRPDC) during 1995–97. Dr. Das is a recipient of the UNT Student Association's Honor Professor Award in 1991 and 1997 for best teaching and scholarly research; UNT's Developing Scholars Award in 1996 for outstanding research; UTA's Outstanding Faculty Research Award in Computer Science in 2001 and 2003; and the UTA College of Engineering Research Excellence Award in 2003. He is also frequently invited as a keynote speaker at international conferences and symposia. Dr. Das' current research interests include mobile wireless communications, resource and mobility management in wireless networks, mobile and pervasive computing, wireless multimedia, ad hoc and sensor networks, mobile internet architectures and protocols, distributed and grid computing, performance modeling and simulation. He has published over 350 research papers in these areas in international journals and conferences, directed numerous industry and government funded projects, and holds five US patents in wireless mobile networks. He received four Best Paper Awards in the ACM MobiCom'99, ICOIN'01, ACM MSWiM'00, and ACM/IEEE PADS'97. He as the Editor in Chief of the Pervasive and Mobile Computing (PMC) journal and also as an Associate Editor of IEEE Transactions on Mobile Computing, ACM/Kluwer Wireless Networks, Parallel Processing Letters, Journal of Parallel, Distributed and Emerging Systems. He served as General Chair of IEEE WoWMoM'05, PerCom'04, IWDC'04, MASCOTS'02, ACM WoWMoM'00-02; General Vice Chair of IEEE PerCom'03, ACM MobiCom'00 and IEEE HiPC'00-01; Program Chair of IWDC'02, WoWMoM'98-99; TPC Vice Chair of ICPADS'02; and as TPC member of numerous IEEE and ACM conferences. He is Vice Chair of the IEEE Computer Society's TCPP and TCCC Executive Committees.     

基站蓄电池差异化维护的必要性

蓄电池的使用寿命和实际容量与温度、均浮充电压等因素密切相关。文中着重分析了影响基站蓄电池使用寿命的主要原因,阐述了如何对基站阀控式蓄电池进行精细化管理延长蓄电池使用寿命,重点对直流中高频开关电源以及蓄电池组的使用配置、维护以及检测等精细化管理相关问题进行探讨。     

Supporting QoS Differentiation in Energy-Constrained Cognitive Radio Networks

Wireless Personal Communications - Routing protocols for cognitive radio ad hoc networks (CRNs) select a route between the source and destination nodes based on the spectrum opportunity at...     

Differentiation applied to lossless compression of medical images

Lossless compression of medical images using a proposed differentiation technique is explored. This scheme is based on computing weighted differences between neighboring pixel values. The performance of the proposed approach, for the lossless compression of magnetic resonance (MR) images and ultrasonic images, is evaluated and compared with the lossless linear predictor and the lossless Joint Photographic Experts Group (JPEG) standard. The residue sequence of these techniques is coded using arithmetic coding. The proposed scheme yields compression measures, in terms of bits per pixel, that are comparable with or lower than those obtained using the linear predictor and the lossless JPEG standard, respectively, with 8-b medical images. The advantages of the differentiation technique presented here over the linear predictor are: 1) the coefficients of the differentiator are known by the encoder and the decoder, which eliminates the need to compute or encode these coefficients, and 21 the computational complexity is greatly reduced. These advantages are particularly attractive in real time processing for compressing and decompressing medical images.     

QoS Differentiation for IEEE 802.16 WiMAX Mesh Networking

Recently IEEE 802.16 WiMAX has attracted a lot of attention in wireless networking research and applications. To enable a flexible and cost-effective deployment, mesh networking mode is defined in WiMAX standard. In this paper, we introduce a system model of WiMAX mesh networking with the focus on entry process, frame structure, centralized and distributed scheduling. The state-of-the-art WiMAX mesh networking research is reviewed. In addition, we propose an effective QoS differentiation scheme for the IEEE 802.16 WiMAX mesh networks. Both collocated scenario and general topology are theoretically analyzed and compared. Illustrative numerical examples are presented to demonstrate the effectiveness of the proposed strategy. The impact of key parameters on the performance is discussed for differentiating multiple classes of services. Several open issues are summarized as a guideline for future topics in WiMAX mesh networking research.     

On Loss Differentiation for CSMA-Based Dense Wireless Network

In this paper, we propose a novel method to differentiate packet loss based on interference energy and timing relative to desired signal in CSMA-based dense wireless networks. All measurements are conducted locally at transmitters without any additional over-the-air overhead. Our method can estimate PER (packet error rate) due to interference prior to or after the beginning of the desired signal separately, allowing for more efficient MAC(media access control) adaptation design.     

多媒体应用需要更多功能和外形差异化

展望新的一年,2006年电子产业的主要热点应用将是那些包括高性能多媒体功能的各种应用,这些可能是基于消费类电子的应用领域,如多媒体手机和便携式媒体播放器(Portable Media Players,PMP)也可能是基于计算领域的应用(computation-based applications).     

时段差异化网络参数动态配置研究

文章顺应后3G时代网络精细优化工作需求,进一步挖掘网络提质潜力,提出"时段差异化"创新优化方法。该方法充分利用网络时段差异特性和不同参数策略特性,从"时间"这个崭新维度引入不同时段网络参数动态配置的思想,改善整体网络质量和用户感知。目前该优化方法已在3G网络应用并获得良好效果,并预期在4G网络中可进一步往时空联动优化作深入研究。