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.     

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...     

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。     

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.     

CIM implementation through at and MRP integration

A CIM implementation case is introduced in this paper. It is accomplished through the integration of two fundamental approaches to production plammng and control; Jrr and MRP. The resultant system is a hybrid where some JIT methodologies prevail, but the benefits of the MRP are also required A new BOM structure is designed for the load leveled production with small lot size and the synchronized production. The overall production planning concept is described with actual data.     

A novel fluidic strain sensor for large strain measurement

A novel fluidic strain sensor is proposed with the use of a mixture of glycerin with aqueous sodium chloride encapsulated within an elastomer as a mean for piezoresistive large strain measurement. Electrochemical impedance spectroscopy (EIS) is conducted for strain response measurement and equivalent circuit analysis is applied for explaining the strain-affected ion transportation behavior of the sensor. The applied strain has caused an increase in both the resistance to charge transfer (R_ct) and the resistance of the salt solution which is reflected in an increase in the resistance of the system (R_sys). A parabolic relationship between the real part of the impedance (Z_re) and the true strain () for an applied strain of up to about 30% is verified. In addition, a novel fluid encapsulation technique by applying oxygen plasma surface modification is introduced. Aqueous sodium chloride is successfully encapsulated within an elastomeric casing with a pattern and this sensor is capable of measuring large strain of even up to about 40%. This method is suggested as an industrial fabrication technique for the strain sensor. The use of ionic liquids for green chemistry has been suggested for years and its use as an electrical conductive media in large strain sensor technology is found to be direct and environmentally friendly.     

实现非对称型NAT穿越的VoIP系统设计方案

基于SIP的VoIP系统在Internet上已经取得广泛应用,但在企业网环境中,由于大量NAT设备的存在,端到端的SIP呼叫难以实现。分析了四类NAT的映射规则及其对SIP消息造成的影响,介绍了现有的NAT穿越方法,最后在STUN方式基础上提出了一种实现非对称型NAT穿越的VoIP系统设计方案。该方案在用户认证服务器和VoIP软终端上各开设一个端口侦听穿越请求,并对收到的包进行相应处理。经过校园网到企业网环境的测试证明该方案能达到很好的接通率。     

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.     

Mental strain and the problem of repeated measurements

In the past, stress and strain arising from the execution of mentally demanding tasks have been measured by means of surveys. Such methods require repeated investigation of the individual perceptions and valuations during task fulfilment to record time-dependent changes in strain levels. However, it is possible that the individual measurement procedures employed in surveys-as artefacts-may cause a change in the stress situation and subsequently in the resulting mental strain. The results of the experiments carried out to investigate this hypothesis verify that repeated measurements have a similar effect as a short break. The repeated measurements taken during progressive studies are, therefore, likely to affect the conditions of stress. A change in the level of mental strain recorded can be expected, particularly if the post-test rating is preceded by a long period of low stress before or during which an additional measurement of strain is implemented.     

SORR回归算法在胆固醇测定中的应用

借鉴分类问题的算法,推广到回归问题中去,针对用于分类问题的SOR(successive overrelaxation for support vector)支持向量机算法,提出SORR(successive overrelaxation for support vector regression)支持向量回归算法,并应用于医学上三类血浆脂蛋白(VLDL、LDL、HDL)测定样本中胆固醇的含量。数值实验表明:SORR算法有效,与标准的支持向量回归SVR算法相比,保持了相同的回归精度,提高了学习速度,为临床上测定胆固醇含量提供新的有效方法。     

Global characterization of biomass-burning patterns using satellite measurements of fire radiative energy

Remote sensing is the most practical means of measuring energy release from large open-air biomass burning. Satellite measurement of fire radiative energy (FRE) release rate or power (FRP) enables distinction between fires of different strengths. Based on a 1-km resolution fire data acquired globally by the MODerate-resolution Imaging Spectro-radiometer (MODIS) sensor aboard the Terra and Aqua satellites from 2000 to 2006, instantaneous FRP values ranged between 0.02 MW and 1866 MW, with global daily means ranging between 20 and 40 MW. Regionally, at the Aqua-MODIS afternoon overpass, the mean FRP values for Alaska, Western US, Western Australia, Quebec and the rest of Canada are significantly higher than these global means, with Quebec having the overall highest value of 85 MW. Analysis of regional mean FRP per unit area of land (FRP flux) shows that at peak fire season in certain regions, fires can be responsible for up to 0.2 W/m² at peak time of day. Zambia has the highest regional monthly mean FRP flux of ~ 0.045 W/m² at peak time of day and season, while the Middle East has the lowest value of ~ 0.0005 W/m². A simple scheme based on FRP has been devised to classify fires into five categories, to facilitate fire rating by strength, similar to earthquakes and hurricanes. The scheme uses MODIS measurements of FRP at 1-km resolution as follows: category 1 (< 100 MW), category 2 (100 to < 500 MW), category 3 (500 to < 1000 MW), category 4 (1000 to < 1500 MW), category 5 (≥ 1500 MW). In most regions of the world, over 90% of fires fall into category 1, while only less than 1% fall into each of categories 3 to 5, although these proportions may differ significantly from day to day and by season. The frequency of occurrence of the larger fires is region specific, and could not be explained by ecosystem type alone. Time-series analysis of the proportions of higher category fires based on MODIS-measured FRP from 2002 to 2006 does not show any noticeable trend because of the short time period.     

存储器内建自测试技术在芯片设计中的应用

针对SoC芯片中存储器模块的测试问题,在结合设计工具的基础上,提出了存储器的测试结构和方法,并且讨论了存储器模型的应用与调试.     

Elastic bar transfer functions determination using one-point strain measurements

Measurements of impulsive forces and pressures by means of the elastic bar require that the effect of waves’ dispersion in the bar on the sensor's output signal be corrected. The correction problem can be solved using deconvolution techniques. For this purpose it is necessary to determine the elastic bar's transfer functions. In this paper, an experimental method of determining the elastic bar's transfer functions in form of formulas is described, which can be used to reconstruct the input waveform. The method is based on: one-point measurement of the elastic strain waves propagating inside the bar, the spectral analysis of these waves and making use of the general solution of the equation of movement of the bar in the frequency domain. The determined transfer functions of the bar are used for impulsive strain waveform reconstruction by means of deconvolution in the frequency domain, and for the validity check of the reconstruction. The application of this method to the reconstruction of impulsive force waveforms generated by the mechanical impact of bodies is presented.