一种Android平台的便携心音心电实时采集系统

针对传统心电仪及心音听诊设备相互独立且不易携带的缺点,设计并实现了一种基于Android平台的便携式心音心电采集系统。该系统由心音和心电采集及信号调理模块,蓝牙数据通信模块和Android系统上位机构成。首先在心音与心电采集与放大电路中将信号进行分别放大和去噪处理,然后通过模数转换将处理后的信号经由蓝牙模块发出;最后使用Android平台设备上位机程序对采集到的心音与心电信号进行接收与实时显示。实际效果表明,所设计的信号调理电路能够有效滤除外界噪声干扰,可以清楚地分辨信号的诊疗特征,极大程度上克服了现有诊断设备的诸多缺点,为个人健康监护以及医务人员外出诊断都提供了一个良好的解决方案。     

Wireless ATM networks: technology status and future directions

The concept of “wireless ATM” (WATM), first proposed in 1992, is now being actively considered as a potential framework for new-generation wireless communication networks capable of supporting integrated, quality-of service (QoS) based multimedia services. In this review paper, we outline the technological rationale for wireless ATM, present a system-level architecture, and discuss key design issues for both mobile ATM switching infrastructure and radio access subsystems. The WATM radio access layer issues covered in this paper include: spectrum allocation; spectrum etiquette; modem technology; and medium access/data link control (MAC/DLC) protocols. Mobile ATM aspects such as ATM signaling extensions for handoff control, location management, and mobile QoS control are discussed. A summary of current wireless/mobile ATM technology development and standardization status is given, including an outline of our WATMnet prototype. The paper concludes with a discussion of future directions for wireless ATM technology such as Internet protocol (IP) integration and mobile multimedia terminals/applications     

人体心电心音信号同步检测系统设计

设计了一种动态心电心音信号同步检测系统,对系统的整体设计方案进行了介绍,采用内置A／D的MSP430F149单片机和USB通信接口传输的采集系统进行同步采集、实时存储,并用VC＋＋6．0开发了客户定征分析软件系统。最后经过临床验证,本系统误差小,实用意义很大。     

基于双因子认证技术的网络身份识别

本文提出了一种基于动态双因子认证技术的网络身份识别方法,用户每次登录的口令是利用系统时间和用户ID通过MD5加密算法计算得到,其通过MD5加密后生成的登录口令是随机的,这将进一步提高开放网络环境下身份识别的可靠性和安全性。同时,本文还提出网络身份识别技术可以应用到各类网站的服务器上,用来完成对用户身份的识别,以提高网络系统的安全性。     

Resilient network design: challenges and future directions

This paper highlights the complexity and challenges of providing reliable services in the evolving communications infrastructure. The hurdles in providing end-to-end availability guarantees are discussed and research problems identified. Avenues for overcoming some of the challenges examined are presented. This includes the use of a highly available network spine embedded in a physical network together with efficient crosslayer mapping to offer survivability and differentiation of traffic into classes of resilience.     

基于LDAP协议与Kerberos认证机制的统一认证

为开发一个企业级的用户身份认证体系,依据目录服务理论,将LDAP协议和Kerberos认证技术相结合,应用于身份认证服务器的结构设计,进行用户统一身份认证和授权,并进一步分析了系统的安全性。     

CATV in France: Present situation and future directions

Fibre-optic systems have been introduced in France initially in the subscriber loop (fibre to the home) for experimenting switched broadband services (Biarritz opened in 1984) and then, under the Plan Cǎble for CATV/multiservice networks (twelve cities or groups of cities, about 900,000 homes), and as CATV trunks and feeders in 40 other cities or groups of cities (another 4,500,000 homes). This unique experience with fibre in the subscriber loop, albeit slightly premature gives some assurance on the future economic feasibility of the fibre-to-the-home or fibre-to-the-office concepts under development. D2-MAC/packet with smart card access control has been selected as the standard for scrambling/enciphering audiovisual signals on cable and on satellite. The integration of the recent hybrid or fibre broadband TV networks and of their network management systems into the telecommunication networks is still being discussed.     

Decomposition and compression for ECG and EEG signals with sequence index coding method based on matching pursuit

An efficient compression method is proposed by encoding the sequence index of atoms based on matching pursuit (MP)algorithm with over-complete Gabor dictionary,which has the merit to adjust the compres...     

基于三角范数的多模态手指生物特征的分数层融合方法

多模态的生物特征融合已成为目前生物识别研究领域的主要发展趋势,从防伪性角度出发,满足普适性和易采集、易接受性的应用需求,提出了基于手指静脉,并结合指纹、指关节纹和指形的分数层融合来实现多模态生物特征的身份认证方案。实验结果表明,本文提出基于Sugeno-Weber三角范数的分数层融合方法,能够增大类内与类间匹配分数分布间的距离,提高了多模态生物特征的身份认证性能。     

User authentication based on foot motion

In nearly all current systems, user authentication mechanism is one time and static. Although such type of user authentication is sufficient for many types of applications, in some scenarios, continuous or periodic re-verification of the identity is desirable, especially in high-security application. In this paper, we study user authentication based on 3D foot motion, which can be suitable for periodic identity re-verification purposes. Three-directional (3D) motion of the foot (in terms of acceleration signals) is collected using a wearable accelerometer sensor attached to the ankle of the person. Ankle accelerations from three directions (up-down, forward-backward and sideways) are analyzed for person authentication. Applied recognition method is based on detecting individual cycles in the signal and then finding best matching cycle pair between two acceleration signals. Using experimental data from 30 subjects, obtained EERs (Equal Error Rates) were in the range of 1.6–23.7% depending on motion directions and shoe types. Furthermore, by combining acceleration signals from 2D and 3D and then applying fusing techniques, recognition accuracies could be improved even further. The achieved performance improvements (in terms of EER) were up to 68.8%.     

Moore's law: past, present and future

A simple observation, made over 30 years ago, on the growth in the number of devices per silicon die has become the central driving force of one of the most dynamic of the world's industries. Because of the accuracy with which Moore's Law has predicted past growth in IC complexity, it is viewed as a reliable method of calculating future trends as well, setting the pace of innovation, and defining the rules and the very nature of competition. And since the semiconductor portion of electronic consumer products keeps growing by leaps and bounds, the Law has aroused in users and consumers an expectation of a continuous stream of faster, better, and cheaper high-technology products. Even the policy implications of Moore's Law are significant: it is used as the baseline assumption in the industry's strategic road map for the next decade and a half     

Optical communications: past, present and future

A quiet revolution is taking place in communications technology, where light is replacing its low-frequency counterparts, the radio wave and signals by wire. The author traces the development of optical communication technology from simple beginnings using fire and beacons, through early valve and solid-state devices to integrated optics and advanced fibre systems. Because of the very rapid growth in the area recently, only a sample of current developments can be presented. Leading-edge developments are considered in the light of current and advancing technologies     

Virtual networks: past, present and future

Virtual networks (VNs) are logical subnetworks contained within larger long-distance networks. VNs make use of the long-distance network to offer voice and data transport and a set of customer-controllable call monitoring and management features. The historical development and motivation for VNs are examined, and the VN architectural components are described. Call flows for on-net and off-net voice and data calls, common VN features, and the future of VNs as both technology and telecommunications needs continue to evolve are discussed     

Commentary: reliability-past, present, and future

The paper reviews the nature of reliability in relation to the causes of failures of engineering products, explains how most of the methods that have been developed and applied by reliability and quality specialists have been misleading and ineffective, and makes suggestions for the way ahead     

Smart cards: present and future applications and techniques

Smart cards, or IC cards, have recently begun to appear in many applications, e.g. banking, telephony and TV decoders. So far their use has been restricted to a set of very specific purposes. However, a smart card contains a microprocessor and a memory, so that it can be used for many functions that are presently performed by other devices, such as papers, keys, purses and also, sometimes, other computers. Smart cards provide a high level of security and enable a new family of information systems to be designed. 100 million IC cards will be manufactured in 1991 throughout the world. The paper is both a survey of the existing technology and an attempt to describe some future possibilities