• Title/Summary/Keyword: Sensor and instruments

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An Evaluation of the Accuracy of Mini-Wright Peak Flowmeters in Patients with Asthma and Chronic Obstructive Pulmonary Disease (천식 및 만성폐쇄성폐질환 환자에서 Mini-Wright Peak Flowmeter로 측정한 최대호기유속의 정확도)

  • Choi, Won-Il;Han, Seung-Beom;Jeon, Young-June
    • Tuberculosis and Respiratory Diseases
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    • v.50 no.3
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    • pp.310-319
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    • 2001
  • Background : The peak flowmeter is very useful in monitoring of out-patients as well as those in emergency departments because of its convenience and simplicity with low cost. There have been many studies aimed at determining the accuracy and reproducibility of the peak flow meter in normal population. However, there is a paucity of reports regarding its accuracy in patients with chronic obstructive pulmonary disease(COPD) or asthma. The accuracy of the peak expiratory flow(PEF) measured with a mini-Wright peak flowmeter was assessed by a comparison with the results of a mass flow sensor. Methods : The PEF measurements were performed in 108 patients aged 19-82 years presenting with either a chronic obstructive lung disease or asthma before and after inhaling salbutamol. The PEF measurements from the mini-Wright flowmeter were compared with those obtained by the calibrated mass flow sensor. Results : The average of the readings taken by the mini-Wright meter were 37-39 l/min higher than those taken by the mass flow sensor. The average percentage error of the mini-Wright meter were higher, ranging less than 300 l/min. The mean of the differences between the values obtained using both instruments (the bias)$\pm$limits of agreement(${\pm}2$ SD) were $37.1{\pm}90\;l/min$ for the PEF(p<0.001). Conclusions : The mini-Wright peak flowmeter overestimated the flows in patients with COPD or asthma. It was also found that the accuracy of the mini-Wright peak flowmeter decreased in its mid to low range. The limits of agreement are wide and the difference between the two instruments is significant. Therefore, the measurements made between the two types of machines in patients with asthma or COPD cannot be used interchangeably.

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Autonomous evaluation of ambient vibration of underground spaces induced by adjacent subway trains using high-sensitivity wireless smart sensors

  • Sun, Ke;Zhang, Wei;Ding, Huaping;Kim, Robin E.;Spencer, Billie F. Jr.
    • Smart Structures and Systems
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    • v.19 no.1
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    • pp.1-10
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    • 2017
  • The operation of subway trains induces secondary structure-borne vibrations in the nearby underground spaces. The vibration, along with the associated noise, can cause annoyance and adverse physical, physiological, and psychological effects on humans in dense urban environments. Traditional tethered instruments restrict the rapid measurement and assessment on such vibration effect. This paper presents a novel approach for Wireless Smart Sensor (WSS)-based autonomous evaluation system for the subway train-induced vibrations. The system was implemented on a MEMSIC's Imote2 platform, using a SHM-H high-sensitivity accelerometer board stacked on top. A new embedded application VibrationLevelCalculation, which determines the International Organization for Standardization defined weighted acceleration level, was added into the Illinois Structural Health Monitoring Project Service Toolsuite. The system was verified in a large underground space, where a nearby subway station is a good source of ground excitation caused by the running subway trains. Using an on-board processor, each sensor calculated the distribution of vibration levels within the testing zone, and sent the distribution of vibration level by radio to display it on the central server. Also, the raw time-histories and frequency spectrum were retrieved from the WSS leaf nodes. Subsequently, spectral vibration levels in the one-third octave band, characterizing the vibrating influence of different frequency components on human bodies, was also calculated from each sensor node. Experimental validation demonstrates that the proposed system is efficient for autonomously evaluating the subway train-induced ambient vibration of underground spaces, and the system holds the potential of greatly reducing the laboring of dynamic field testing.

System identification of soil behavior from vertical seismic arrays

  • Glaser, Steven D.;Ni, Sheng-Huoo;Ko, Chi-Chih
    • Smart Structures and Systems
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    • v.4 no.6
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    • pp.727-740
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    • 2008
  • A down hole vertical seismic array is a sequence of instruments installed at various depths in the earth to record the ground motion at multiple points during an earthquake. Numerous studies demonstrate the unique utility of vertical seismic arrays for studying in situ site response and soil behavior. Examples are given of analyses made at two sites to show the value of data from vertical seismic arrays. The sites examined are the Lotung, Taiwan SMART1 array and a new site installed at Jingliao, Taiwan. Details of the installation of the Jingliao array are given. ARX models are theoretically the correct process models for vertical wave propagation in the layered earth, and are used to linearly map deeper sensor input signals to shallower sensor output signals. An example of Event 16 at the Lotung array is given. This same data, when examined in detail with a Bayesian inference model, can also be explained by nonlinear filters yielding commonly accepted soil degradation curves. Results from applying an ARMAX model to data from the Jingliao vertical seismic array are presented. Estimates of inter-transducer soil increment resonant frequency, shear modulus, and damping ratio are presented. The shear modulus varied from 50 to 150 MPa, and damping ratio between 8% and 15%. A new hardware monitoring system - TerraScope - is an affordable 4-D down-hole seismic monitoring system based on independent, microprocessor-controlled sensor Pods. The Pods are nominally 50 mm in diameter, and about 120 mm long. An internal 16-bit micro-controller oversees all aspects of instrumentation, eight programmable gain amplifiers, and local signal storage.

A study on the development of satellite dynamic simulator hardware (위성체 성능 시험 장치 개발에 관한 연구)

  • 용상순;김영학;김진철
    • 제어로봇시스템학회:학술대회논문집
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    • 1993.10a
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    • pp.788-792
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    • 1993
  • The objective of this study is to develope a satellite dynamic simulator, which can test and analyze the performance of spacecraft attitude control, antenna pointing instruments, communication equipments and spacecraft components under the space environment. The satellite simulator can be used to predict the events such as malfunction and failure of satellites in space during operation and can be used to protect against emergencies. At first, the performance test system of attitude control is investigated which can simulate motion and verify stability of spacecraft. Our system consists of an attitude control main processor and a sub-processor including some real hardwares such as attitude sensors and actuators. In this paper, we describe the procedure of designing and manufacturing the dynamic simulator hardware, which consists of the central processor board, the sub-processor board and the sun sensor, and also communication between the components.

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Control System Design of Pelvis Platform for Biped Walking Stability (이족보행 안전성을 위한 골반기구의 제어시스템 설계)

  • Kim, Su-Hyeon;Yang, Tae-Kyu
    • Journal of Institute of Control, Robotics and Systems
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    • v.15 no.3
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    • pp.306-314
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    • 2009
  • The pelvis platform is the mechanical part which accomplishes the activities of diminishing the disturbances from the lower body and maintaining a balanced posture. When a biped robot walks, a lot of disturbances and irregular vibrations are generated and transmitted to the upper body. As there are some important machines and instruments in the upper body or head such as CPU, controller units, vision system, etc., the upper part should be isolated from disturbances or vibrations to functions properly and finally to improve the biped stability. This platform has 3 rotational degrees of freedom and is able to maintain balanced level by feedback control system. Some sensors are fused for more accurate estimation and the control system which integrates synchronization and active filtering is simulated on the virtual environment.

INSTRUMENTATION AND CONTROL STRATEGIES FOR AN INTEGRAL PRESSURIZED WATER REACTOR

  • UPADHYAYA, BELLE R.;LISH, MATTHEW R.;HINES, J. WESLEY;TARVER, RYAN A.
    • Nuclear Engineering and Technology
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    • v.47 no.2
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    • pp.148-156
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    • 2015
  • Several vendors have recently been actively pursuing the development of integral pressurized water reactors (iPWRs) that range in power levels from small to large reactors. Integral reactors have the features of minimum vessel penetrations, passive heat removal after reactor shutdown, and modular construction that allow fast plant integration and a secure fuel cycle. The features of an integral reactor limit the options for placing control and safety system instruments. The development of instrumentation and control (I&C) strategies for a large 1,000 MWe iPWR is described. Reactor system modeling-which includes reactor core dynamics, primary heat exchanger, and the steam flashing drum-is an important part of I&C development and validation, and thereby consolidates the overall implementation for a large iPWR. The results of simulation models, control development, and instrumentation features illustrate the systematic approach that is applicable to integral light water reactors.

Comparison of the Monitored Forests Results from EO-1 Hyperion , ALI and Landsat 7 ETM+

  • Tan, Bingxiang;Li, Zengyuan
    • Proceedings of the KSRS Conference
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    • 2003.11a
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    • pp.1307-1309
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    • 2003
  • The EO-1 spacecraft, launched November 21, 2000 into a sun synchronous orbit behind Landsat 7, hosts advanced technology demonstration instruments, whose capabilities are currently being assessed by the user community for future missions. A significant part of the EO-1 program is to perform data comparisons between Hyperion, ALI and Landsat 7 ETM+. In this paper, a comparison of forest classification results from Hyperion, ALI, and the ETM+ of Landsat-7 are provided for Wangqing Forest Bureau, Jilin Province, Northeast China. The data have been radiometrically corrected and geometrically resampled. Feature selection and statistical transforms are used to reduce the Hyperion feature space from 86 channels to 14 features. Classes chosen for discrimination included Larch, Spruce, Oak, Birch, Popular and Mixed forest and other landuses. Classification accuracies have been obtained for each sensor. Comparison of the classification results shows : Hyperion classification results were the best, ALI's were much better than ETM+.

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The basic investigation for the objective study on the pulsation (맥진의 현대적인 객관화 연구를 위한 기반조사 - I. 기계적 측정법에 대한 비교연구-)

  • Kim Gyeong Cheol;Shin Soon Shik;Kang Hee Jung;Cha Chul Yong
    • Journal of Physiology & Pathology in Korean Medicine
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    • v.17 no.5
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    • pp.1147-1150
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    • 2003
  • Modern Objectification of Pulse Diagnosis, One of the Four Diagnosis Method of Oriental Medicine, is necessarily project to improving Oriental medical clinic status and quality by standardization of diagnosis database. At that, accurate measurement equipment or devices(sensor, system and instruments, etc,) to exactly detect MacSang(脈診 : the parameter and subject of pulse diagnosis) have not developed yet. Existing Pulse diagnosis devices are not satisfy clinical needs and medical equipments quality. We study for pulse diagnosis system, that CD is satisfying oriental medical clinic needs, is ensuring accuracy and reappearance to support in clinical diagnosis and treatment, is guaranteeing the quality of medical equipments. theoretical base and convenience.

Characterization of three-dimensional ultrasonic anemometer using phase measurement (위상측정방식을 이용한 3차원 초음파 풍향풍속계의 특성분석)

  • Park, Do-Hyun;Yeh, Yun-Hae
    • Journal of Sensor Science and Technology
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    • v.15 no.6
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    • pp.442-448
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    • 2006
  • Ultrasonic anemometers using pulse envelope detection-based method are standard instruments in most meteorological studies. In this paper, a new phase measurement method is tried to achieve the enhanced resolution without changing dimensions. The measurement sensitivity, dynamic range, and measurement speed of the new instrument are 0.2 mm/s, 13.3 m/s, and 13 measurements/sec, respectively. A graphic user interface is added to show the velocity and direction of the wind with the speed of sound and temperature of the wind in the 3 dimensional space. The new anemometer could be useful for the measurement of the air speed, the flow of fluids, and even air flow inside the downtown buildings.

Efficiency of Superconducting Gravimeter Observations and Future Prospects

  • Neumeyer Juergen
    • Korean Journal of Remote Sensing
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    • v.21 no.1
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    • pp.15-29
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    • 2005
  • Superconducting Gravimeters (SG) are the most sensitive instruments for measuring temporal gravity variations. The gravimeter is an integrating sensor therefore the gravity variations caused by different sources must be separated for studying a special effect by applying different models and data analysis methods. The present reduction methods for gravity variations induced by atmosphere and hydrosphere including the ocean and the detection and determination of the most surface gravity effects are shown. Some examples demonstrate the combination of ground (SG) and space techniques especially the combination of SG with GRACE satellite derived temporal gravity variations. Resulting from the performance of the SG and the applied data analysis methods some proposals are made for future SG applications.