无线体征监测系统的低功耗调度方法

基于超宽带(UWB)体域网和异构的生理传感器,设计了可对多种生理信息进行实时采集与处理的无线体征监测系统,并针对此类系统提出了基于体征状态机的低功耗调度方法,以便长期监测人体的健康与安全。在该调度方法中,协调器根据系统的体征状态机自适应地确定下一监测周期的传感器集合,并控制相应的生理传感器进行协同工作。仿真结果表明在同样的监测情况下,建议的调度方法有效减少了多生理传感器的不必要运行和无线传输的数据量,从而延长了整个监测系统的工作寿命。     

基于rPPG的生理指标测量方法综述

远程光电容积脉搏波描记法（remote photoplethysmography,rPPG）是指通过摄像头等传感器来捕捉由心动周期造成的皮肤颜色周期性变化的技术。利用rPPG技术可以提取血液体积脉冲信号,进而测量心率、呼吸率和心跳变异性等心动周期相关的生理指标。近年基于rPPG的生理指标测量方法取得了飞速发展,准确性和鲁棒性已得到了大幅提高。该类技术的算法流程主要包括图像/视频的获取和感兴趣区域提取、血液体积脉冲信号提取和生理指标测量等步骤。基于这一算法流程,本文从算法所依据的假设或先验知识出发,对相关文献进行了总结和讨论。此外,还从评测任务、评测数据、评测指标及评测协议等4个方面系统整理针对基于rPPG的生理指标测量方法的评价体系。最后,本文讨论了该领域当前所面临的挑战并展望了可能的技术路线。     

Dynamic strain measurements by fibre Bragg grating sensor

In this work, we describe a fibre Bragg grating (FBG) sensing system for static and dynamic strain measurements. Low cost and simple grating-based demodulation technique has been used to interrogate the strain induced Bragg wavelength shift. Experimental results showing the capability of the proposed system to perform static strain measurements with 1 μ resolution and a linear response are presented. The same system was also used for dynamic strain detection. Here, a fibre grating was bonded to a piezoceramic actuator in different configurations. A laser triangulation-based system has been used as reference measurements up to 10 kHz while dynamic strain measurements by FBG have been carried out up to 50 kHz demonstrating a dynamic resolution of ≈40 n/Hz^1/2, leading to the possibility to perform high frequency detection for on-line structural health monitoring in civil, aeronautic, and aerospace applications.     

Computer-aided appearance design based on BRDF measurements

This paper presents a comprehensive and efficient framework for computer-aided appearance design based on BRDF (bidirectional reflectance distribution function) measurements. It covers all stages of a new product development including acquisition, processing and modeling of reflectance data, interactive rendering and evaluation of material appearance, and manufacturing operations. The proposed method eliminates the need of making a real physical prototype by providing a reliable surface appearance design process in which he/she can faithfully simulate the final surface appearance in the early design stage of a product. In addition, it enables us to manufacture the coating surface the same as the computer simulated surface from the known coating specification. The accuracy test between a real sample and the computer simulated one demonstrates that the proposed method satisfies an acceptable level of accuracy for industrial applications. A case study has been conducted to evaluate the user preference on the surface appearance of a digital handheld device which contains a combination of different coating surfaces. The case study successfully demonstrates that the user preference can be identified using the proposed method while changing the combination of different coating surfaces represented by BRDFs considering factors such as surrounding environments and age groups.     

Perceptual and physiological heat strain: Examination in firefighters in laboratory- and field-based studies

Firefighting demands performing heavy muscular work under adverse and potentially dangerous conditions. Although the physiological and psychological responses to simulated firefighting activities have been described, the heat strain has not been characterised using standardised indices of exercise–heat strain. The purpose of the study is to describe the physiological and perceptual strain associated with working in personal protective equipment and performing simulated firefighting activities in a hot environment using recently developed strain indices (Physiological Strain Index (PhSI); Perceptual Strain Index (PeSI)). Data from two previously published studies (Smith et al. 1995 Smith, D. L. 1995. Selected physiological and psychological responses to physical activity in different configurations of firefighting gear. Ergonomics, 38: 2065–2077. [Taylor & Francis Online], [Web of Science ®] , [Google Scholar], 2001 Smith, D. L. 2001. Effect of strenuous live-fire fire fighting drills on hematological, blood chemistry and psychological measures. Journal of Thermal Biology, 26: 375–379. [Crossref], [Web of Science ®] , [Google Scholar]) – one a laboratory-based study and one a field-based study – were re-analysed incorporating the strain indices. The laboratory study involved walking on a treadmill for 15 min while wearing three different clothing and equipment configurations. The field study involved three trials of standardised firefighting tasks in a live-fire training structure (mean trial length = 5.76 min). Heart rate, rectal temperature, thermal sensations and ratings of perceived exertion were collected in each study. PhSI and PeSI values were calculated using the formulae developed by Moran et al. (1998b Moran, D. S., Shitzer, A. and Pandolf, K. B. 1998b. A physiological strain index to evaluate heat stress. American Journal of Physiology, 275: R129–R134. [Crossref], [PubMed], [Web of Science ®] , [Google Scholar]) and Tikuisis et al. (2002 Tikuisis, P., McLellan, T. M. and Selkirk, G. 2002. Perceptual versus physiological heat strain during exercise-heat stress. Medicine & Science in Sports & Exercise, 34: 1454–1461. [Crossref], [PubMed], [Web of Science ®] , [Google Scholar]), respectively. PhSI and PeSI increased significantly over time in both studies. Even relatively brief bouts of exercise while wearing heavy impermeable clothing or simulated firefighting activity in the heat results in moderate to high levels of heat strain as assessed by PhSI and PeSI.     

可穿戴无线生理参数监测设备的设计与实现

随着微处理器单元（ MCU）和低功耗无线通信技术发展,可穿戴计算成为当前的研究热点。基于低功耗无线通信技术,设计了一种能够实时监测人体脉搏及体温信息的腕带式可穿戴设备。由于采用反射性光电传感器和红外传感器,本系统携带方便,无需利用胸带就能够测量静止或运动状态下的心率信息,从而不影响日常活动。实测结果验证了系统实现的可行性。     

人体生理参数测量系统低功耗设计与实现

为解决无市电情况下人体生理参数的长期监测问题,采用近年新推出的光反射器NJL5501R和心电监护模拟前端芯片AD8232,利用动态电源管理、动态时钟频率控制等低功耗技术,设计了一种以STM32L152微处理器为核心的人体生理参数测量系统.实验结果表明:该系统能够完成人体血氧、心电、温度等参数的测量,具有低功耗、小体积的特点,可实现生理参数的长时间监测.     

Comparison of two different cooling systems in alleviating thermal and physiological strain during prolonged exercise in the heat

Abstract

This study compared the efficacy of an ice vest comprising of water (WATER) or a water-carbon (CARBON) emulsion on thermophysiological responses to strenuous exercise in the heat. Twelve male cyclists completed three 50-minute constant workload trials (55% of peak power output, ambient temperature 30.4?±?0.6°C) with WATER, CARBON, and without ice vest (CONTROL), respectively. The increase in core body temperature (Tcore) was lower in WATER at 40 (?0.49?±?0.34 °C) and 50?minutes (?0.48?±?0.48 °C) and in CARBON at 30 (?0.41?±?0.48 °C), 40 (?0.54?±?0.51 °C), and 50?minutes (?0.67?±?0.62 °C) as compared to CONTROL (p?<?0.05, ES > 0.8). While heart rate and blood lactate kinetics did not differ between the conditions, statistical main effects in favour of both WATER and CARBON were found for thermal sensation (condition p?<?0.001 and interaction p?<?0.01) and rating of perceived exertion (condition p?<?0.05). Per-cooling with CARBON and WATER similarly reduced Tcore but not physiological strain during prolonged exercise in the heat.

Practitioner Summary: Exercise in the heat is characterised by increases in thermophysiological strain. Both per-cooling with a novel carbon-based and a conventional water-based ice vest were shown to reduce core temperature significantly. However, due to its lower mass, the carbon-based system may be recommended especially for weight-bearing sports.     

Observability through delayed measurements: a new approach to state observers design

An original approach for the construction of state observers for dynamic systems is presented in this article. New notions of observability (delay-observability and delay-drift-observability), useful for the development of the observer equations and for the convergence proof, are introduced and compared with other standard observability concepts. In particular, it is shown that delay-drift-observability is an extension of the well-known drift-observability property. The construction of the proposed observer is straightforward and does not require any coordinate transformation of the system into a canonical form, which is a common feature of many other approaches. A numerical example is reported, where a system that is not drift-observable is considered. In this case, the proposed observer is easily constructed and performs well.     

键盘原因导致电磁干扰超标的分析与改进

在单片机应用领域中,实现键盘接口的方式有直接输入、矩阵结构和用专用控制器件等多种.HIC998(3)T型IC卡电话机采用矩阵式键盘,在"3C"认证测试中出现电磁干扰(EMI)超标问题.采用排除法确定超标的原因是由键盘引起的.针对该问题提出采用I2C接口的单口线A/D转换式键盘进行改造的方案.改造后的话机通过测试实验,验...     

Analysis and design of packaged and ESD protected BiCMOS RF front‐end for a UHF receiver

The design of packaged and ESD protected RF front‐end circuits for UHF receiver working at ISM band is presented. By extensively evaluating the effects of the package and ESD parasitics on the LNA input impedance, transconductance, and noise figure, some useful guidelines on the design of inductively degenerated common emitter LNA with package and ESD protection are provided. In addition, by taking advantage of both the bipolar and MOSFET devices, a BiFET mixer with low noise and high linearity is also described in this article. With the careful consideration of the tradeoffs among noise figure, linearity, power gain, and power consumption, the front‐end is implemented in a generic low‐cost 0.8‐μm BiCMOS technology. The on‐board measurement of the packaged RF front‐end circuits demonstrates a 20.3‐dB power gain, 2.6‐dB DSB noise figure, and ?9.5‐dBm input referred third intercept point while consuming about 3.9‐mA current. © 2007 Wiley Periodicals, Inc. Int J RF and Microwave CAE, 2007.     

Hook技术及其在监控键盘输入中的应用

介绍了Hook技术的基本原理和方法,对常用的几种Hook类型进行分析。并通过Hook技术实现对键盘输入的监控。     

不完全量测下的水下纯方位系统目标跟踪算法

针对观测器探测概率小于1的不完全量测情况下的水下纯方位系统的目标跟踪问题,提出了不完全量测下的基于扩展卡尔曼滤波的目标跟踪算法。首先,建立不完全量测情况下的水下纯方位目标跟踪数学模型;其次,在数据出现不完全量测时,采用前一次的更新值对缺失数据进行弥补并完成滤波;最后,采用最优理论性能下界(CRLB)和均方根误差(RMSE)这两种评价准则对此算法进行评估。仿真实验结果表明:在不完全量测下的水下纯方位系统的目标跟踪问题中,所提出的基于扩展卡尔曼滤波的目标跟踪算法在保证预期跟踪精度的前提下,具有较高的实时性。     

片上网络路由节点优化设计

针对虚输出队列结构的路由节点所构成的片上网络(NoC),提出了一种定制化路由节点中各个虚拟通道缓存大小的方法,以提高片上网络的整体通信性能。在有限的片上缓存资源约束下,分析各个虚输入队列中缓存大小对数据通过片上网络的平均延迟的影响,并在此基础上提出一种缓存资源配置方法,以便将缓存资源分配到片上网络通信瓶颈处,从而在不增加缓存资源开销的情况下提高片上网络的通信性能。最后通过仿真验证了路由节点优化设计对提高片上网络性能的可行性,并同未优化的路由节点构成的片上网络性能进行了比较。     

Eliminate angular color shift in top‐emitting OLEDs through cavity design

OLEDs suffer from viewing angle dependent spectral shift due to microcavity effects. To address this issue, we introduce a novel top‐emitting OLED with a dielectric spacer that forms multiple cavity modes. The resulting device shows almost no color shift at different viewing angles.     

一个基于生理计算的羽毛球训练分析系统

通过在国家羽毛球队和北京体育大学的现场调研分析了当前羽毛球训练中存在的问题,针对这些问题设计实现了Physiological Plan系统。系统分为硬件层、数据处理层、算法层和界面层。硬件层采用Berkeley Tricorder平台,数据处理层通过适配器模式将各个传感器的数据统一;算法层包括滤波算法、峰值检测算法以及Outlier检测算法等,界面层与教练进行交互,并将结果呈现给教练。该系统能同时采集和分析运动员的心电图（ECG）、肌电图（EMG）和3D加速度等信息,并将数据分析处理结果反馈给教练,解决了当前羽毛球训练中无法实时采集分析运动员生理数据的问题。实验结果表明该系统可以有效辅助教练员监控和分析运动员训练和比赛时的状态。     

ODBC的数据访问技术

阐述了ODBC（Open Database Connectivity)的ADO(ActiveX Data Object),RDO(Remote Data Objects),DAO(Data Access Objects)三种数据访问技术的异同,主要介绍了ADO技术在网页制作方面的应用。     

Recognizing chinese characters through interactive activation and competition

Most conventional approaches to Chinese character recognition attempt to recognize unknown Chinese characters per se. Hence the discriminative power of features employed play a crucial role in determining the ultimate recognition rate. However, high level linguistic knowledge such as the strong word context effects present in the Chinese language and the different frequencies of words in the daily use of the language, are not utilized in machine recognition of Chinese characters. In this paper, a word-oriented recognizer using the Interactive Activation and Competition model (IAC model) is proposed. Such a recognizer is tolerant to noise, size and font variations and it also possesses self-learning capability.     

ARBAN-A new method for analysis of ergonomic effort

ARBAN is a method for the ergonomic analysis of work, including work situations which involve widely differing body postures and loads. The idea of the method is thal all phases of the analysis process that imply specific knowledge on ergonomics are teken over by filming equipment and a computer routine. All tasks that must be carried out by the investigator in the process of analysis are so designed that they appear as evident by the use of systematic common sense. The ARBAN analysis method contains four steps: 1. Recording of the workplace situation on video or film. 2. Coding the posture and load situation at a number of closely spaced 'frozen' situations. 3. Computerisation. 4. Evaluation of the results. The computer calculates figures for the total ergonomic stress on the whole body as well as on different parts of the body separately. They are presented as 'Ergonomic stress/ time curves', where the heavy load situations occur as peaks of the curve. The work cycle may also be divided into different tasks, where the stress and duration patterns can be compared. The integral of the curves are calculated for single-figure comparison of different tasks as well as different work situations.