• Title/Summary/Keyword: response measurement

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Introducing an Online Measurement System Using Item Response Theory and Computer Adaptive Testing Methods for Measuring the Physical Activity of Community-Dwelling Frail Older Adults

  • Choi, Bong-sam
    • 한국전문물리치료학회지
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    • 제26권3호
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    • pp.106-114
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    • 2019
  • Background: It is difficult to assess whether community-dwelling frail older adults may remain pre-frail status or improve into a robust state without being directly checked by health care professionals. The health information perceived by older adults is considered to be one of best sources of potential concerns in older adult population. An online measurement system combined with item response theory (IRT) and computer adaptive testing (CAT) methods is likely to become a realistic approach to remotely monitor physical activity status of frail older adults. Objects: This article suggests an approach to provide a precise and efficient means of measuring physical activity levels of community-dwelling frail older adults. Methods: Article reviews were reviewed and summarized. Results: In comparison to the classical test theory (CTT), the IRT method is empirically aimed to focus on the psychometric properties of individual test items in lieu of the test as a whole. These properties allow creating a large item pool that can capture the broad range of physical activity levels. The CAT method administers test items by an algorithm that select items matched to the physical activity levels of the older adults. Conclusion: An online measurement system combined with these two methods would allow adequate physical activity measurement that may be useful to remotely monitor the activity level of community-dwelling frail older adults.

충전기 고조파 잡음에 강인한 배터리 내부저항 측정 시스템 (Battery Internal Resistance Measurement System Robust to Charger Harmonic Noise)

  • 이형규;김기택
    • 전기전자학회논문지
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    • 제24권4호
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    • pp.1129-1135
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    • 2020
  • 배터리를 사용함에 따라 노화가 진행되면 배터리의 충전 가능 용량을 나타내는 State of Health(SoH)가 줄어들게 된다. 배터리 모니터링 시스템(BMS)에서 SoH를 추정하는 것이 매우 중요하며, 이를 위해 배터리 내부 저항을 측정하는 방법이 많이 사용된다. 일반적으로 배터리에 특정한 주파수의 전류원을 인가하고 전압응답을 측정하여 내부저항을 연산한다. 충전기가 동작할 경우 전압응답에 충전 고조파 잡음이 발생하여 저항 측정의 정확도가 떨어진다. 본 논문에서는 충전잡음의 영향을 제거하기 위하여 강인한 배터리 내부저항 측정 알고리즘을 제안하였다. 전류원 신호와 전압응답 신호를 일정한 주기 동안 적분하여 잡음을 제거하는 방법으로 우수한 정확도와 안정된 연산결과를 보였다. 무정전 전원장치용 BMS에 적용하여 제안한 방법의 유용함을 입증하였다.

혈압측정의 정확성 평가 (Evaluating the Accuracy of Blood Pressure Measurement)

  • 조성현;황정해;김은경;오병희;김창엽
    • 한국의료질향상학회지
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    • 제3권1호
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    • pp.94-103
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    • 1996
  • Background : Blood pressure is an important indicator in diagnosis and assessing treatment of a patient. Clinical staffs use blood pressure on the assumption that measured value is accurate and reliable. However, whether measured blood pressure is accurate has been rarely investigated in Korea. Objectives : The aims of this study are to evaluate clinical staffs' knowledge and technique as well as accuracy of sphygmomanometer. Also the program to improve the measurement is developed. Methods : Seventy-three registered nurses were asked nine multiple choice questions including Korotkoff sound, cuff size, and deflation rate. Simultaneously characteristics of nurses were examined, age, working place, duration of employment and academic degree. A testing videotape(Standardizing Measurement Video-Tutored Course) was used for evaluating the accuracy of measurement. Testees were to read and record the 12 cases of blood pressure measurement, watching a falling mercury column and hearing Korotkoff sounds. After 10 minutes' education, they were again tested with the same cases. Additionally, 83 mercury sphygmomanometers were checked to find defects such as inaccurate calibration and zero setting, leaky bladder, etc. Results: For the knowledge testing correct response rate was 41.1%. They were the lowest in selecting the proper cuff size and Korotkoff sound. In examining accuracy of blood pressure with videotape, nurses had 67.7% correct response rate. The correct response rate was significantly improved by a session of education. About 23% of sphygmomanometers was without discernable defects. Conclusion : The knowledge and skill of clinical staffs along with the accuracy of equipment have to be improved. A properly designed education program would contribute to the accuracy improvement of blood pressure measurement. Also, more concerns should be given to the precision and maintenance of equipment.

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스파크플러그 주위의 HC 농도 측정 및 연소특성 분석 (Measurement of HC Concentration near Spark Plug and Combustion Analysis)

  • 조한승;송해박;이종화;이귀영
    • 한국자동차공학회논문집
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    • 제6권2호
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    • pp.212-219
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    • 1998
  • Unburned hydrocarbon is a key contributor to both the fuel economy and emissions of automotive engine. Cyclic variation of HC emission is of importance, especially during throttle transients. The real time measurement of hydrocarbon is particularly important to obtain a better understanding of the mechanisms for combustion and emissions, especially during cold start and throttle transient condition. This paper reports the cycle resolved measurement technique of unburned hydrocarbons to quantify rapid changes of in-cylinder concentration in the vicinity of spark plug by using the Fast Response Flame Ionization Detector(FRFID). While this instrument actually measures fuel concentration, its results can be indicative of the AFR behaviour. In order to understand the rapid change of hydrocarbons with cylinder pressure, it is necessary to study the response time delay of the system, including the time associated with gas transportation to FID. And signal from FRFID is correlated with cylinder pressure data to relate changes in mixture preparation to the classic analysis, such as indicated mean effective(IMEF) and ignition delay, etc.

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Dynamic torsional response measurement model using motion capture system

  • Park, Hyo Seon;Kim, Doyoung;Lim, Su Ah;Oh, Byung Kwan
    • Smart Structures and Systems
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    • 제19권6호
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    • pp.679-694
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    • 2017
  • The complexity, enlargement and irregularity of structures and multi-directional dynamic loads acting on the structures can lead to unexpected structural behavior, such as torsion. Continuous torsion of the structure causes unexpected changes in the structure's stress distribution, reduces the performance of the structural members, and shortens the structure's lifespan. Therefore, a method of monitoring the torsional behavior is required to ensure structural safety. Structural torsion typically occurs accompanied by displacement, but no model has yet been developed to measure this type of structural response. This research proposes a model for measuring dynamic torsional response of structure accompanied by displacement and for identifying the torsional modal parameter using vision-based displacement measurement equipment, a motion capture system (MCS). In the present model, dynamic torsional responses including pure rotation and translation displacements are measured and used to calculate the torsional angle and displacements. To apply the proposed model, vibration tests for a shear-type structure were performed. The torsional responses were obtained from measured dynamic displacements. The torsional angle and displacements obtained by the proposed model using MCS were compared with the torsional response measured using laser displacement sensors (LDSs), which have been widely used for displacement measurement. In addition, torsional modal parameters were obtained using the dynamic torsional angle and displacements obtained from the tests.

Development of Fast-Response Portable NDIR Analyzer Using Semiconductor Devices

  • Kim, Woo-Seok;Lee, Jong-Hwa;Park, Young-Moo;Yoo, Jai-Suk;Park, Kyoung-Seok
    • Journal of Mechanical Science and Technology
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    • 제17권12호
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    • pp.2099-2106
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    • 2003
  • In this paper, a novel fast response NDIR analyzer (FRNDIR), which uses an electrically pulsed semiconductor emitter and dual type PbSe detector for the PPM-level detection of carbon dioxide (CO$_2$) at a wavelength of 4.28 $\mu\textrm{m}$, is described. Modulation of conventional NDIR energy typically occurs at 1 to 20 Hz. To achieve real time high-speed measurement, the new analyzer employs a semiconductor light emitter that can be modulated by electrical chopping. Updated measurements are obtained every one millisecond. The detector has two independent lead selenide (PbSe) with IR band pass filters. Both the emitter accuracy and the detector sensitivity are increased by thermoelectric cooling of up to -20 degrees C in all semiconductor devices. Here we report the use of semiconductor devices to achieve improved performance such that these devices have potential application to CO$_2$ gas measurement and, in particular, the measurement of fast response CO$_2$ concentration at millisecond level.

Importance of Volumetric Measurement Processes in Oncology Imaging Trials for Screening and Evaluation of Tumors as Per Response Evaluation Criteria in Solid Tumors

  • Vemuri, Ravi Chandra;Jarecha, Rudresh;Hwi, Kim Kah;Gundamaraju, Rohit;MaruthiKanth, Aripaka;Kulkarni, AravindRao;Reddy, Sundeep
    • Asian Pacific Journal of Cancer Prevention
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    • 제15권5호
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    • pp.2375-2378
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    • 2014
  • Cancer, like any disease, is a pathologic biological process. Drugs are designed to interfere with the pathologic process and should therefore also be validated using a functional screening method directed at these processes. Screening for cancers at an appropriate time and also evaluating results is also very important. Volumetric measurement helps in better screening and evaluation of tumors. Volumetry is a process of quantification of the tumors by identification (pre-cancerous or target lesion) and measurement. Volumetric image analysis allows an accurate, precise, sensitive, and medically valuable assessment of tumor response. It also helps in identifying possible outcomes such disease progression (PD) or complete response as per Response Evaluation Criteria in Solid Tumors (RECIST).

Color accuracy of imaging using color filters

  • Boher, P.;Leroux, T.;Patton, V. Collomb;Bignon, T.
    • Journal of Information Display
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    • 제13권1호
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    • pp.7-16
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    • 2012
  • In this paper, the problem concerning the color accuracy of imaging systems using color filters is examined. It is shown that the only solution to the problem is to build systems with the spectral response matching the CIE curves as closely as possible. If the spectral response does not closely match the CIE curves, it was demonstrated that calibration cannot solve the problem and will result in very unstable colorimeters. A practical solution that uses telecentric lenses on the sensor side in addition to dedicated color filters for each CCD detector is presented. For systems that closely match the CIE curves, an innovative method of improving the color accuracy based on the precise measurement of the spectral response is presented. The small discrepancies in the spectral response with regard to the CIE curves are corrected in different ways during the measurements. Finally, it is shown that the tristimulus calibration that is used for display measurement is very unstable for systems without CIE matching and is much more stable with systems that closely match the CIE curves.

Novel LUT Measurement Method for Response Time Compensation

  • Kim, Tae-Sung;Park, Bong-Im
    • 한국정보디스플레이학회:학술대회논문집
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    • 한국정보디스플레이학회 2004년도 Asia Display / IMID 04
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    • pp.331-334
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    • 2004
  • A new measurement scheme is proposed to generate an optimized boost table for video rate LCD response time compensation. This method, which closely follows basic theory, enables up to a 90% reduction in the lookup table creation time compared to conventional methods. Furthermore, while conventional approaches require all measurements to be repeated in order to load the entire LUT whenever key parameters such as refresh rate or boost intensity are modified, the method proposed in this paper allows the new table to be calculated by utilizing saved waveform data without the need for any repeated measurements.

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탠덤 비행체의 선구탄두 기폭 충격 측정 시스템 구현 (Explosion Shock Measurement System of the Precursor Warhead for the Tandem Projectile)

  • 최동혁;안지연;김유범;손중탁;이욱준;박현수
    • 한국군사과학기술학회지
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    • 제24권5호
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    • pp.503-510
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    • 2021
  • This paper presents a system that measures the acceleration of the shock caused by the explosion of the precursor warhead for the tandem projectile. The proposed system, which is implemented based on the MIL-STD-810G, Method 517.1, consists of a miniaturized shock measurement device, a cable, accelerometers, and a trigger circuit. The shock measurement device has a size of ¢102 × 171 mm and cable has a length of 3 m. The operational confirmation test is conducted by implementing the measurement system. The Analysis of shock data(accelerometer output data) is carried out using Shock Response Spectrum(SRS), pseudo velocity and plot of acceleration time transient. Through measurement analysis, one can predict the damage of electronics in projectile when precursor warhead is exploded.