Switched-voltage: an adaptation of switched-currents forvoltage-mode design

A novel sampled data signal processing technique is proposed, termed switched-voltage (SV). The technique is a dual approach to the recent switched-current technique. As with switched-current, the switched-voltage technique overcomes the incompatibility of the classical switched-capacitor technique to standard digital CMOS processes. The technique also relaxes the need for linear voltage-to-current and current-to-voltage converters in switched-currents for interfacing to the application environment     

User-oriented views in health care information systems

In this paper, we present the methodology we adopted in designing and developing an object-oriented database system for the management of medical records. The designed system provides technical solutions to important requirements of most clinical information systems, such as 1) the support of tools to create and manage views on data and view schemas, offering to different users specific perspectives on data tailored to their needs; 2) the capability to handle in a suitable way the temporal aspects related to clinical information; and 3) the effective integration of multimedia data. Remote data access for authorized users is also considered. As clinical application, we describe here the prototype of a user-oriented clinical information system for the archiving and the management of multimedia and temporally oriented clinical data related to percutaneous transluminal coronary angioplasty (PTCA) patients. Suitable view schemas for various user roles (cath-lab physician, ward nurse, general practitioner) have been modeled and implemented on the basis of a detailed analysis of the considered clinical environment, carried out by an object-oriented approach.     

Integrated scheduling and link adaptation for heterogeneous networks: design and performance analysis

ABSTRACT

This paper presents novel integrated scheduling and link adaptation (ISLA) schemes for links which have a common spectrum and possibly different rates and reliability constraints. We consider the problem of weighted sum average rate maximisation of wireless links. In an orthogonal transmission system, a link is selected using instantaneous signal-to-noise (SNR) of all the links, and its rate and power are set in a jointly optimised manner. To demonstrate the effectiveness of the proposed approach, we analyse ISLA schemes with continuous rate adaptation using constant or adaptive transmission powers. ISLA schemes are designed in similar settings for practical discrete rate-adaptive systems using adaptive modulation and coding. To this end, a design framework is presented, which relies on a partitioning of space of links’ SNRs into regions, similar to structured vector quantisation. Within this framework, a particular ISLA design with high performance and polynomial complexity is suggested. The proposed schemes are designed before the start of the transmission, based on closed-form solutions, and can easily be applied to multiple access or broadcast networks. We also analyse several schemes for comparison, which employ modified Round-Robin, opportunistic scheduling or online generalised scheduling. Numerical results demonstrate how the proposed ISLA schemes outperform the benchmark schemes and effectively meet various user requirements.¹     

Three-dimensional reconstruction of microcalcification clustersfrom two mammographic views

Classification of benign/malignant microcalcification clusters is a major diagnostic challenge for radiologists. Clinical studies have revealed that the shape of the cluster, and the spatial distribution of individual microcalcifications within it, are important indicators of its malignancy. However, mammographic images of clustered microcalcifications confound their three-dimensional (3-D) distribution with image projection and breast compression. This paper presents a novel model-based method for reconstructing microcalcification clusters in 3-D from two mammographic views (cranio-caudal and medio-lateral oblique--"shoulder to the opposite hip" or lateral-medio). We develop a 3-D breast representation and a parameterised breast compression model which constraints geometrically the possible 3-D positions of a calcification in a two-dimensional image. Corresponding calcifications in the two views are matched using an estimate of the calcification volume. Both the geometric constraint and the matching criterion are utilized in the final reconstruction step to build the 3-D reconstructed clusters. Validation experiments are described using 30 clusters to verify the individual steps of the model, and results consistent with known ground truth are obtained. Some of the approximations in the model and future work are discussed in the concluding section.     

Virtual world control system using sensed information and adaptation engine

The sensed information (e.g., temperature, humidity, light intensity, gas intensity) obtained from a user's vicinity plays an important role in the generation of environmental changes, the main character's reactions, and in storyline changes in the virtual world. In this paper, a method is proposed to transform sensed information from real world to standardized XML instances and to control virtual world objects. The sensed information from the real world is transformed into XML instances standardized by MPEG-V Part 5 (Data formats for Interaction Device) schemes and then delivered to a Real-to-Virtual (RV) adaptation engine. The engine generates another XML instance standardized by MPEG-V Part 4 (Virtual world object characteristics) that describes the control information of avatars and objects in the virtual world. The system is demonstrated by a real-world mock-up equipped with a sensor set and a virtual space realized in Second Life.     

The Eos data and information system: concepts for design

A functional architecture for the Earth observing system (Eos) is presented and a variety of management issues are surveyed, including longevity, coordination with agencies, scientific programs, and other nations, incorporation of existing data, and the importance of effective and responsible scientific governance by the users. The author concludes that to meet its objectives, the system must facilitate the development of abstract higher-level data structures and data manipulation languages. If that occurs, the Eos data and information system will, he believes, stimulate novel and more powerful modes of thought about the information that portrays the evolution of the Earth system     

信息传播、信息认知与视觉设计艺术的关系研究

随着科学技术的不断发展,信息化成为视觉设计艺术的趋势和潮流,而了解信息传播发送及传播相关知识成为进行视觉信息创造的前提和基础,基于此本文阐述了信息传播与信息认知的基本理论,论述了信息传播、信息认知与视觉艺术设计的关系。     

Creativity in design: the contribution of information technology

Efforts to improve the design process in new product development often take the form of new information technologies, and they have had varying degrees of success. This paper considers the modern technologies of design and their impact on creativity. The analysis considers such design issues as problem structure, engineering knowledge, expert systems, ideation and the social context of technologies that affect their adoption and use. There exists a general bias toward the goals of effective coordination over enhanced creativity in the systems supporting design. Suggestions for research and practice are discussed     

Automatic design rule adaptation of leaf cell layouts

The automatic adaptation of mask layouts to new design rules is considered. A new concept is presented that is based on geometric operations and mask compaction. The geometric operation MELT is discussed in detail; the other operations OR, AND, ANDNOT, OVERSIZE and UNDERSIZE are derived from it. The mask compaction consists mainly of a design rule analysis phase and the execution of a longest path algorithm. Contrary to symbolic compaction the mask compaction is based on polygon edges rather than symbols. With the example of the buried contact it is shown that even relatively complex design rule requirements may be met. Tests with several mask layouts sometimes led to overconstrained conditions. These conditions are located with the aid of a longest path algorithm that has not been applied to compaction programs up to now. Furthermore the inconsistent constraint cycles are broken by a fast jog generation algorithm.     

Wiener design of adaptation algorithms with time-invariant gains

A design method is presented that extends least mean squared (LMS) adaptation of time-varying parameters by including general linear time-invariant filters that operate on the instantaneous gradient vector. The aim is to track time-varying parameters of linear regression models in situations where the regressors are stationary or have slowly time-varying properties. The adaptation law is optimized with respect to the steady-state parameter error covariance matrix for time-variations modeled as vector-ARIMA processes. The design method systematically uses prior information about time-varying parameters to provide filtering, prediction, or fixed lag smoothing estimates for arbitrary lags. The method is based on a transformation of the adaptation problem into a Wiener filter design problem. The filter works in open loop for slow parameter variations, whereas a time-varying closed loop has to be considered for fast variations. In the latter case, the filter design is performed iteratively. The general form of the solution at each iteration is obtained by a bilateral Diophantine polynomial matrix equation and a spectral factorization. For white gradient noise, the Diophantine equation has a closed-form solution. Further structural constraints result in very simple design equations. Under certain model assumptions, the Wiener designed adaptation laws reduce to LMS adaptation. Compared with Kalman estimators, the channel tracking performance becomes nearly the same in mobile radio applications, whereas the complexity is, in general, much lower     

Optimum pulse amplitude modulation--I: Transmitter-receiver design and bounds from information theory

Intersymbol interference and additive noise are two common sources of distortion in data transmission systems. For pulse amplitude modulation (PAM) communication links, the combination of transmitter waveform and linear receiver that minimizes the mean-squared error arising from these sources is determined. An extension to include the effects of timing jitter is performed in a companion paper. Performance characteristics of the optimal PAM systems, showing the mean-squared error versus the signal-to-noise ratio, are determined explicitly for several examples. These characteristics are compared both with those of certain suboptimal systems and with the optimal performance theoretically attainable (OPTA), derived by combining Shannon's concepts of the capacity of a channel and the rate distortion function of a source. The optimal PAM systems are seen to perform very close to the OPTA for low signal-to-noise ratios. For high signal-to-noise ratios, however, the mean-squared error of optimal PAM systems decreases as the reciprocal of the signal-to-noise ratio, but the OPTA decreases more rapidly, except for band-limited channels. The performance of PAM systems can be improved at high signal-to-noise ratios by coding techniques. One such technique, called Shannon-Cantor coding, is discussed briefly.     

Temporal information based GoP adaptation for linear video delivery schemes

An original wireless video transmission scheme called SoftCast has been recently proposed to deal with the issues encountered in conventional wireless video broadcasting systems (e.g. cliff effect). In this paper, we evaluate and optimize the performance of the SoftCast scheme according to the transmitted video content. Precisely, an adaptive coding mechanism based on GoP-size adaptation, which takes into account the temporal information fluctuations of the video, is proposed. This extension denoted Adaptive GoP-size mechanism based on Content and Cut detection for SoftCast (AGCC-SoftCast) significantly improves the performance of the SoftCast scheme. It consists in modifying the GoP-size according to the shot changes and the spatio-temporal characteristics of the transmitted video. When hardware capacities, such as buffer or processor performance are limited, an alternative method based only on the shot changes detection (AGCut-SoftCast) is also proposed. Improvements up to 16 dB for the PSNR and up to 0.55 for the SSIM are observed with the proposed solutions at the cut boundaries. In addition, temporal visual quality fluctuations are reduced under 1dB in average, showing the effectiveness of the proposed methods.     

关于嵌入式电子信息产品检测信息采集系统的设计

随着当前社会科技发展不断进步,所出现电子信息产品也越来越多,为社会发展提供很大帮助。在电子信息产品发展以及应用过程中,为能够保证产品质量,需要对其进行检测,而检测信息的采集是分析检测结果在一个重要环节,因此,选择合理采集系统便有着十分重要作用。嵌入式信息采集系统是当前一种新型系统,本文就嵌入式电子信息产品检测信息采集系统的设计进行分析。     

System for infectious disease information sharing and analysis: design and evaluation.

Motivated by the importance of infectious disease informatics (IDI) and the challenges to IDI system development and data sharing, we design and implement BioPortal, a Web-based IDI system that integrates cross-jurisdictional data to support information sharing, analysis, and visualization in public health. In this paper, we discuss general challenges in IDI, describe BioPortal's architecture and functionalities, and highlight encouraging evaluation results obtained from a controlled experiment that focused on analysis accuracy, task performance efficiency, user information satisfaction, system usability, usefulness, and ease of use.     

水下信息网框架研究与设计

水下信息网的总体设计方案直接影响了整个网络的建设质量。从需求分析、功能分析与配置、综合集成、系统分析和控制等四个阶段出发,分析了水下信息网的功能和性能需求,结合相关技术现状,将系统分为四个子系统,分析了各子系统的主要作用。同时,以供电子系统为例,提出了该子系统的初步设计方案,由此扩展最终完成了水下信息网的总体设计方案。     

车载信息系统终端的研究与设计

为了便于汽车的远程控制与管理,进行了车载信息系统终端的研究与设计。车载终端作为汽车内外信息沟通的重要平台,设计了车载终端的软件和硬件,以及CAN总线节点的软件和硬件,配合监控中心和Android手机客户端,可以实现对车辆进行监控、管理、调度和远程故障诊断等功能。最后对系统进行集成与测试,测试结果表明,车载终端工作正常,可以与CAN总线节点以及上位机之间进行通信实现相应功能。验证了车载终端软件和硬件设计方案的正确性。本文网络版地址：http：//www.eepw.com.cn/article/271646.htm     

Collision-aware design of rate adaptation for multi-rate 802.11 WLANs

One of the key challenges in designing a rate adaptation scheme for IEEE 802.11 wireless LANs (WLANs) is to differentiate bit errors from link-layer collisions. Many recent rate adaptation schemes adopt the RTS/CTS mechanism to prevent collision losses from triggering unnecessary rate decrease. However, the RTS/CTS handshake incurs significant overhead and is rarely activated in today's infrastructure WLANs. In this paper we propose a new rate adaptation scheme that mitigates the collision effect on the operation of rate adaptation. In contrast to previous approaches adopting fixed rate-increasing and decreasing thresholds, our scheme varies threshold values based on the measured network status. Using the "retry" information in 802.11 MAC headers as feedback, we enable the transmitter to gauge current network state. The proposed rate adaptation scheme does not require additional probing overhead incurred by RTS/CTS exchanges and can be easily deployed without changes in firmware. We demonstrate the effectiveness of our solution by comparing with existing approaches through extensive simulations.     

合同管理信息系统的分析与设计

合同管理是现代企业管理的重要组成部分,运用计算机对合同进行管理是未来的发展方向。针对合同管理信息系统开发的难点问题,在前期调研的基础上遵循软件工程的思想和方法进行了分析与设计。首先,运用用例建模进行需求分析,确定了各种角色的系统需求;然后,运用层次图进行概要设计,确定了主要模块及其功能;最后,运用IPO图以销售合同为例来说明数据操作的详细设计方法。运用合同管理系统,可以满足企业内部信息及时传递、快速响应、高效共享等方面的需求,为企业提高经济效益、管理水平和信息化进程服务。     

基于SOA技术的管理信息系统设计

在分析科技成果管理信息系统平台开放、标准、集成的实际需求的基础上,阐述了基于.NET技术和面向服务架构(SOA)的科技成果管理信息系统平台。提出了业务组件化、服务化、应用分层的设计思想,对系统运行流程、各软件层和组件的功能进行了论述,提出了系统关键层的设计要求和实现方法.通过对系统一年多的实际应用结果表明,采用基于SOA模式的系统架构可以很好地满足科技成果管理系统的流程变化和异构系统的集成,同时也大大提高了程序编写的效率。     

平安城市的信息安全防护体系设计

平安城市的发展致力于大安全防护体系，重点保障各种网络中资源的有效融合，并保障资源再使用过程中的可控可管，既保证有效用户对资源的实时访问，又能对非法用户的访问进行禁止。目前各种网络中大多已经建设了各自独立的安全防护体系，在资源整合的过程中必然涉及到安全防护体系的融合，因此构建一个能够支持各种安全体系融合信息安全防护方案已经成为平安城市未来信息安全防护的必然趋势。