基于Zigbee的人体心电信号无线监测系统的设计

提出了一种基于Zigbee技术的人体心电信号无线监测系统设计方案;采用Zigbee技术和STM32W108ARM芯片设计了系统采集节点和汇聚节点的硬件电路,采用C语言编写了其软件,实现人体心电信号的采集和无线传输;利用Labview软件设计人体心电监测界面,实现了利用PC机对采集到的心电信号进行实时监测;实验表明,该监测系统通信质量良好,能够实现心电信号的采集、波形显示,以及心率值和心电频谱的分析,在家庭医疗领域具有较高的应用价值。     

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STM32和μC/OS-II的心电检测系统

详细介绍了一种基于STM32和μC/OS-Ⅱ的心电数据检测系统设计与实现.采用STM32F103ZET6作为微处理器,配有TFT液晶屏面显示模块和SD卡数据存储/读写模块等,并利用μC/GUI进行图形界面管理.该系统实现了对心电信号的采集和处理,在液晶屏上进行实时显示和触摸屏操作控制,并将数据存储在SD卡中以便传输到PC机等功能.     

基于STM32的微型多参数健康监护终端的设计

阐述了一种基于STM32F103RE单片机的微型多参数健康监护终端的设计与实现方法。系统采用集成化的硬件设计方案并针对各种生理信号的特点进行了算法优化,提高了使用的便捷性和监测的准确度。终端实现了人体心电、心率、血氧饱和度和姿态信息的采集、处理、显示与存储,并且可以通过蓝牙与Android或iOS智能设备进行数据交互,在使用者生理参数异常或跌倒时发出报警信号。     

基于MICA技术的胎儿心电信号提取的应用研究

多维独立分析（Multidimensional Independent Component Analysis,MICA）方法适用于实现多分量信号分析和分量提取,可实际应用于对胎儿心电信号的提取。为了说明MICA算法分离结果的可靠性,利用动态心电合成模型生成仿真的心电信号数据进行了验证,用vkMICA、cfMICA、SJADE、MSOBI四种MICA算法对实际采集到孕妇心电数据集进行了处理。实验结果显示,四种MICA算法可提取出较纯净的胎儿心电信号,并能较好地反映出胎儿心电信号的实际特征。     

人体HRV信号的检测及其最大李雅普诺夫指数估算

介绍了一种便携式心电监测仪器,用于监测人心电(ECG)信号.根据获得的心电信号数据,采用小波变换技术进行心电R峰的准确定位,进而得到心率变异(Heart Rate Variability,HRV)信号序列.在对HRV信号进行相空间重构的基础上进行关联维、最大李雅普诺夫指数的估算.结果表明,健康者和心率不齐者的HRV信号的最大李雅普诺夫指数均为正值,但处于心率不齐状态HRV的最大李雅普诺夫指数低于健康状态的最大李雅普诺夫指数.     

结合ICA和PCA方法的胎儿心电提取

在生物医学信号处理领域,独立分量分析（PCA）和主分量分析（ICA）是两种广泛应用的方法。但是,这两种方法各有其优缺点。提出了一种新颖的方法,将ICA和PCA相结合,通过求相关的技术,分别取ICA和PCA方法的优点。将该方法应用于从母体腹部测得的多通道信号中提取胎儿心电信号的实验,得到令人满意的结果。研究结果表明,这种结合ICA和PCA的方法能够比较准确地分离出所需要的胎儿心电信号,进而可以对胎儿心电进行监护,因此在临床上具有一定的实用价值。     

结合ICA和PCA方法的胎儿心电提取

在生物医学信号处理领域,独立分量分析(PCA)和主分量分析(ICA)是两种广泛应用的方法。但是,这两种方法各有其优缺点。提出了一种新颖的方法,将ICA和PCA相结合,通过求相关的技术,分别取ICA和PCA方法的优点。将该方法应用于从母体腹部测得的多通道信号中提取胎儿心电信号的实验,得到令人满意的结果。研究结果表明,这种结合ICA和PCA的方法能够比较准确地分离出所需要的胎儿心电信号,进而可以对胎儿心电进行监护,因此在临床上具有一定的实用价值。     

基于STM32单片机的无线运动传感器节点设计

本文介绍了一个用于移动端反映人体运动与心率状态的无线运动传感器节点设计,同时具有运动分析的功能以及低功耗的特性。系统以STM32F103C8T6作为主控制器,通过ADS1292模块采集心电信号、LMT70模块采集温度数据、ADXL345模块获得运动状态数据,将数据传入单片机后进行分析运算与处理,将获得的心电波形、温度数据、运动数据实时地显示在单片机控制的屏幕上,同时通过HC05蓝牙模块,将数据无线传输至移动端,并在移动端显示。     

基于巨磁阻抗传感器的心磁信号检测的研究

针对心磁图仪诊断技术在临床上的普及需求和心磁图检查费用高昂的矛盾现状,提出了一种基于巨磁阻抗传感器的心磁信号采集和信号处理方法。该方法依据心磁信号和心电信号的相关性,通过以巨磁阻抗传感器为核心的数据采集电路,同步采集两种信号,并根据功率谱密度分析结果,自动调整带通滤波器的参数,使其能自适应跟踪心电信号的频率,滤除噪声信号,最后取得心磁信号。通过实验证明了该方案可在常温下准确测得心磁信号,且设备维护成本低,操作简单易行。     

Fast and precise points-to analysis

Many software engineering applications require points-to analysis. These client applications range from optimizing compilers to integrated program development environments (IDEs) and from testing environments to reverse-engineering tools. Moreover, software engineering applications used in an edit-compile cycle need points-to analysis to be fast and precise.In this article, we present a new context- and flow-sensitive approach to points-to analysis where calling contexts are distinguished by the points-to sets analyzed for their call target expressions. Compared to other well-known context-sensitive techniques it is faster in practice, on average, twice as fast as the call string approach and by an order of magnitude faster than the object-sensitive technique. In fact, it shows to be only marginally slower than a context-insensitive baseline analysis. At the same time, it provides higher precision than the call string technique and is similar in precision to the object-sensitive technique. We confirm these statements with experiments using a number of abstract precision metrics and a concrete client application: escape analysis.     

源代码分析技术的理论与实践发展

源代码分析技术对于软件安全缺陷分析是一项非常重要的手段.分析了软件源代码分析工具的技术手段和发展过程,最后对源代码分析的理论和实践进行了分析总结.     

C语言的别名分析方法研究

别名分析对于数据流分析、程序优化和分析工具的实现非常重要.文章提出了一种需求驱动,流非敏感的分析算法来解决指针别名问题.通过构造程序表达式图(PEG)把指针别名问题转化成判断两个指针节点是否是联通的问题,它不同于传统的别名分析方法,它不需要构造别名集合和对其求交集,所以提高了分析指针别名的效率.     

A system to assist survey analysts

The researcher who knows little about computers but wants to conduct a survey and analyse the results by computer can land himself in some difficulty if he does not appreciate some of the problems of computerization. This paper describes a system which is designed to aid such a person by providing assistance with the design of the questionnaire, the capturing of the data and the final analyses.     

The use of protocol analysis for determining ability requirements for personnel selection on a computer-based task

Abstract

The role of cognitively oriented tasks in the workplace continues to increase as automation of physical task components advances. Difficulties in automating the operator's cognitive processes have placed a renewed emphasis on the human component in advanced manufacturing systems. While traditional task analysis techniques have made significant contributions to improving productivity when important task elements are visually observable, their focus on manual task procedures make them less effective for cognitively oriented activities. This research has made a first attempt at integrating techniques from several disciplines to develop a cognitive task analysis methodology. The utility of this combined approach is examined for a new system being tested in the United States Postal Service. This task requires operators to encode, via a keyboard, addresses presented on a video display terminal. Results support the hypothesis that, for cognitively oriented tasks, a consensus based analysis technique (the Position Analysis Questionnaire) can be significantly improved by including data from task analysis provided the methodology is suitable for identifying non-physical task components.     

A novel analysis space for pointer analysis and its application for bug finding

The size of today’s programs continues to grow, as does the number of bugs they contain. Testing alone is rarely able to flush out all bugs, and many lurk in difficult-to-test corner cases. An important alternative is static analysis, in which correctness properties of a program are checked without running it. While it cannot catch all errors, static analysis can catch many subtle problems that testing would miss.We propose a new space of abstractions for pointer analysis—an important component of static analysis for C and similar languages. We identify two main components of any abstraction—how to model statement order and how to model conditionals, then present a new model of programs that enables us to explore different abstractions in this space. Our assign-fetch graph represents reads and writes to memory instead of traditional points-to relations and leads to concise function summaries that can be used in any context. Its flexibility supports many new analysis techniques with different trade-offs between precision and speed.We present the details of our abstraction space, explain where existing algorithms fit, describe a variety of new analysis algorithms based on our assign-fetch graphs, and finally present experimental results that show our flow-aware abstraction for statement ordering both runs faster and produces more precise results than traditional flow-insensitive analysis.     

基于因子分析法和聚类分析法的副省级城市宜居情况聚类评价

重点选取了15个副省级城市的第一产业比重、人口密度、人均绿地、园林面积、医院数目,市政建设面积、地方财政税收等42个指标,使用SPSS作为计算工具,使用因子分析方法简化评价指标,计算相关系数矩阵,判别因子分析可行性,利用主成分分析法求因子载荷,将因子进行旋转得出更有实际意义的因子解释,并计算因子得分,利用该结果计算Mi...     

Cost analysis of object-oriented bytecode programs

Cost analysis statically approximates the cost of programs in terms of their input data size. This paper presents, to the best of our knowledge, the first approach to the automatic cost analysis of object-oriented bytecode programs. In languages such as Java and C#, analyzing bytecode has a much wider application area than analyzing source code since the latter is often not available. Cost analysis in this context has to consider, among others, dynamic dispatch, jumps, the operand stack, and the heap. Our method takes a bytecode program and a cost model specifying the resource of interest, and generates cost relations which approximate the execution cost of the program with respect to such resource. We report on COSTA, an implementation for Java bytecode which can obtain upper bounds on cost for a large class of programs and complexity classes. Our basic techniques can be directly applied to infer cost relations for other object-oriented imperative languages, not necessarily in bytecode form.     

数据分析需求与实现

数据分析是从海量数据中发现隐含信息或知识的过程。基于一个公安破案辅助数据分析系统,深入研究数据分析任务的需求与实现,提出首先规划分析思路、细化分析功能,然后用多视角数据透视和智能分析两种手段,从微观与宏观、定量与定性等不同角度互为补充地使系统具有完备的分析功能。该研究对如何开发具有实用价值的数据分析系统有普遍的指导意义。