低功耗便携式多导联心电信号采集系统设计

针对家用医疗监护领域的需求,设计了一种低功耗、便携式多导联心电信号采集系统。采用直流耦合方法,通过生物电位测量ADS1298模拟前端,实现微弱心电信号的采集。在模拟前端中,心电信号经过可编程仪表放大器进行放大,进入24位高分辨率模/数转换器(ADC)转换成数字信号;采用STM32F103微处理器进行控制,通过低功耗ZigBee实现心电信号的无线传输;设计了预处理电路、右腿驱动和屏蔽线驱动电路减小了高频和共模干扰;系统采用锂电池供电,体积小(7 cm×8 cm×2 cm),功耗低(214. 5 m W)。实验结果表明:设计的系统能长时间、稳定、有效地提取心电信号。     

基于移动医疗服务系统中的前置放大器设计与实现

本文主要介绍由三运放结构仪表放大器AD623组成的差动输入方式的生物电前置放大器设计,通过对生物电前置放大器性能的分析,给出适合生物信号要求的设计电路,并结合实验证明该电路的合理性.基于移动医疗服务系统功耗低的特点,采用运放单电源供电电路,可实现成本低廉,结构简单,性能优越的设计.     

一种12GHz的高增益低噪声放大器

通过分析GaAs pHEMT器件特性设计了一款两级高增益、低功耗的低噪声放大器.采用两级结构提高低噪声放大器的增益,设计了一种共用电流结构,降低了放大器的功耗,同时降低电路噪声.输入、输出匹配均采用LC阶梯匹配网络,具有良好的匹配性,并使用CAD软件对电路进行设计优化.电路仿真结果表明,在中心频率12 GHz下实现了增...     

基于移动医疗服务系统中的前置放大器设计与实现

本文主要介绍由三运放结构仪表放大器AD623组成的差动输入方式的生物电前置放大器设计,通过对生物电前置放大器性能的分析,给出适合生物信号要求的设计电路,并结合实验证明该电路的合理性。基于移动医疗服务系统功耗低的特点,采用运放单电源供电电路,可实现成本低廉,结构简单,性能优越的设计。     

一种低功耗Sigma-Delta调制器的设计

采用改进的单环二阶2bit调制器架构和低功耗AB类放大器电路,实现了一种应用于无线收发机系统中的低功耗Sigma-Delta调制器。利用Matlab/Simulink进行了建模仿真,优化调制器系数,并采用TSMC0.18μmCMOS工艺进行了电路设计。电路仿真结果表明,在采样频率为1.2288MHz、过采样率为64时,调制器的信号噪声谐波失真比达到77.0dB,功耗为1.18mW,具有低功耗特点。     

基于简易直流电子负载的高精度测量仪

本系统具有电路精致,额外负担小的特点。在功耗方面,采用低功耗单片MSP430F169,以及低功耗元器件,如稳压模块tps5430等,有效降低整个系统的功耗。     

手持式RFID读写器的低功耗设计与测试

为满足手持式RFID读写器的低功耗要求,提出了一种在低功耗硬件的基础上,通过软件调节系统的工作时钟频率和管理系统的工作模式来降低读写器系统功耗的设计方法.并为测试系统的功耗设计了相应的测试软件.测试结果表明,该低功耗设计方法可有效地降低系统的功耗.     

一种高速低功耗存储读写控制电路

本文提出了一种高速低功耗存储读写控制电路。该电路采用锁存器型敏感放大器,并将敏感放大器输入与存储器位线通过隔离电路互联,通过控制隔离电路和敏感放大器开启时机,可以有效实现存储器读出速度、读数据功耗和读出可靠性之间的折衷。文章给出的模拟分析结果对存储器设计者有很好的参考价值。     

低功耗数字涡街流量计硬件研制中的关键技术

数字涡街流量计采用了数字频谱分析与带通滤波器组相结合的方式,在低功耗情况下,它能保证最大限度地滤除流量信号中混杂的噪声信号.根据降压型DC/DC与低压差线性稳压器(LDO)的转换特点,搭建了高效率的电源转换电路,为系统提供最大的可用电流.同时,电路设计选用低功耗器件,并根据工作状态对一些器件或者电路进行选通,最大程度地降低了系统的功耗.经实际测试表明,系统性能达到了涡街流量计的工业要求.     

一种具有温压补偿功能气体涡轮流量计的设计

设计了基于MSP430单片机的具有温度压力补偿功能的气体涡轮流量计,介绍了该系统的硬件电路和程序设计.以MSP430F149单片机为处理芯片,有效降低了系统的功耗,该系统采用高性能的温度压力传感器进行温度压力补偿,确保了系统的精度,同时温度压力传感器等器件均采用低功耗器件进一步降低了系统功耗.     

Only connect: teaching, technology and telesis

Abstract This paper describes an approach to the design of interactive multimedia materials being developed in a European Community project. The developmental process is seen as a dialogue between technologists and teachers. This dialogue is often problematic because of the differences in training, experience and culture between them. Conditions needed for fruitful dialogue are described and the generic model for learning design used in the project is explained.     

European Community policy and the market

Abstract This paper starts with some reflections on the policy considerations and priorities which are shaping European Commission (EC) research programmes. Then it attempts to position the current projects which seek to capitalise on information and communications technologies for learning in relation to these priorities and the apparent realities of the marketplace. It concludes that while there are grounds to be optimistic about the contribution EC programmes can make to the efficiency and standard of education and training, they are still too technology driven.     

一种自适应子融合集成多分类器方法

融合集成方法已经广泛应用在模式识别领域,然而一些基分类器实时性能稳定性较差,导致多分类器融合性能差,针对上述问题本文提出了一种新的基于多分类器的子融合集成分类器系统。该方法考虑在度量层融合层次之上通过对各类基多分类器进行动态选择,票数最多的类别作为融合系统中对特征向量识别的类别,构成一种新的自适应子融合集成分类器方法。实验表明,该方法比传统的分类器以及分类融合方法识别准确率明显更高,具有更好的鲁棒性。     

煤矿井下安全监控分站的设计及其仿真实现

为了设计一种具有低成本、低功耗、易操作、功能强且可靠性高的煤矿井下安全分站,针对煤矿安全生产实际,文章提出了采用MCS-51系列单片机为核心、具有CAN总线通信接口的煤矿井下安全监控分站的设计方案;首先给出煤矿井下安全监控分站的整体构架设计,然后着重阐述模拟量输入信号处理系统的设计过程,最后说明单片机最小系统及其键盘、显示、报警、通信等各个组成部分的设计;为验证设计方案的可行性与有效性,使用Proteus软件对设计内容进行仿真验证,设计的煤矿井下安全监控分站具有瓦斯、温度等模拟量参数超标报警功能和电机开停、风门开闭等开关量指示功能;仿真结果表明:设计的煤矿井下安全监控分站具有一定的实际应用价值.     

Avoiding semantic and temporal gaps in developing software intensive systems

Development of software intensive systems (systems) in practice involves a series of self-contained phases for the lifecycle of a system. Semantic and temporal gaps, which occur among phases and among developer disciplines within and across phases, hinder the ongoing development of a system because of the interdependencies among phases and among disciplines. Such gaps are magnified among systems that are developed at different times by different development teams, which may limit reuse of artifacts of systems development and interoperability among the systems. This article discusses such gaps and a systems development process for avoiding them.     

Designing economic np control charts: A programmed simulation approach

This paper presents control charts models and the necessary simulation software for the location of economic values of the control parameters. The simulation program is written in FORTRAN, requires only 10K of main storage, and can run on most mini and micro computers. Two models are presented - one describes the process when it is operating at full capacity and the other when the process is operating under capacity. The models allow the product quality to deteriorate to a further level before an existing out-of-control state is detected, and they can also be used in situations where no prior knowledge exists of the out-of-control causes and the resulting proportion defectives.     

The development of robot art

Going through a few examples of robot artists who are recognized worldwide, we try to analyze the deepest meaning of what is called “robot art” and the related art field definition. We also try to highlight its well-marked borders, such as kinetic sculptures, kinetic art, cyber art, and cyberpunk. A brief excursion into the importance of the context, the message, and its semiotics is also provided, case by case, together with a few hints on the history of this discipline in the light of an artistic perspective. Therefore, the aim of this article is to try to summarize the main characteristics that might classify robot art as a unique and innovative discipline, and to track down some of the principles by which a robotic artifact can or cannot be considered an art piece in terms of social, cultural, and strictly artistic interest. This work was presented in part at the 13th International Symposium on Artificial Life and Robotics, Oita, Japan, January 31–February 2, 2008     

Explanation and prediction: an architecture for default and abductive reasoning

Although there are many arguments that logic is an appropriate tool for artificial intelligence, there has been a perceived problem with the monotonicity of classical logic. This paper elaborates on the idea that reasoning should be viewed as theory formation where logic tells us the consequences of our assumptions. The two activities of predicting what is expected to be true and explaining observations are considered in a simple theory formation framework. Properties of each activity are discussed, along with a number of proposals as to what should be predicted or accepted as reasonable explanations. An architecture is proposed to combine explanation and prediction into one coherent framework. Algorithms used to implement the system as well as examples from a running implementation are given.     

View-based model-driven architecture for enhancing maintainability of data access services

In modern service-oriented architectures, database access is done by a special type of services, the so-called data access services (DAS). Though, particularly in data-intensive applications, using and developing DAS are very common today, the link between the DAS and their implementation, e.g. a layer of data access objects (DAOs) encapsulating the database queries, still is not sufficiently elaborated, yet. As a result, as the number of DAS grows, finding the desired DAS for reuse and/or associated documentation can become an impossible task. In this paper we focus on bridging this gap between the DAS and their implementation by presenting a view-based, model-driven data access architecture (VMDA) managing models of the DAS, DAOs and database queries in a queryable manner. Our models support tailored views of different stakeholders and are scalable with all types of DAS implementations. In this paper we show that our view-based and model driven architecture approach can enhance software development productivity and maintainability by improving DAS documentation. Moreover, our VMDA opens a wide range of applications such as evaluating DAS usage for DAS performance optimization. Furthermore, we provide tool support and illustrate the applicability of our VMDA in a large-scale case study. Finally, we quantitatively prove that our approach performs with acceptable response times.     

A pragmatic multi-method investigation of discrepant technological events: Coping,attributions, and ‘accidental’ learning

Discrepant technological events or situations that entail a problem, a misunderstanding or a difficulty with the Information Technology (IT) being employed, are common in the workplace, and can lead to frustration and avoidance behaviors. Little is known, however, about how individuals cope with these events. This paper examines these events by using a multi-method pragmatic approach informed by coping theory. The results of two studies – a critical incident study and an experiment – serve to build and test, respectively, a theoretical model that posits that individuals use a variety of strategies when dealing with these events: they experience negative emotions, make external attributions, and adopt engagement coping strategies directed at solving the event, eventually switching to a disengagement coping strategy when they feel they have no control over the situation. Furthermore, users’ efforts may result in ‘accidental’ learning as they try to overcome the discrepant IT events through engagement coping. The paper ends with a discussion of the results in light of existing literature, future opportunities for research, and implications for practice.