• 제목/요약/키워드: Reliability of Measurement

검색결과 2,422건 처리시간 0.036초

맥진기 판독의 신뢰도 및 파형의 재현성 연구 (Study on Reliability of Interpretation and Reproducibility of a Pulse Analyser)

  • 박승찬;이지혜;이혜윤;조민경;김도형;김소연;최준용;한창우;박성하;홍진우;이인;권정남
    • 대한한방내과학회지
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    • 제34권3호
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    • pp.231-239
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    • 2013
  • Objectives : This study was performed to evaluate inter-rater and intra-rater reliability of interpretation and reproducibility of a pulse analyser (MAXMAC27-Plus). Methods : 38 of 40 volunteers completed the pulse analysis consecutively. Three Korean medical doctors who had at least 2 years of clinical experience interpreted the pulse waves for 3 aspects of size, depth and shape, then inter-rater reliability and crude agreement was obtained. Reinterpretation was done 2 weeks later and intra-rater reliability and crude agreement was obtained. Intra-rater reliability and crude agreement between 1st and 2nd measurement was calculated. Cohen's weighted kappa for size, Cohen's kappa for depth and shape were used as statistical analysis. Results : Inter-rater reliability of size, depth and shape among 3 raters was 0.598, 0.604, and 0.312, respectively, showing moderate to substantial agreement. Average intra-rater reliability between 1st and 2nd interpretation of size, depth and shape was 0.806, 0.705, and 0.638, respectively, showing substantial to almost perfect agreement. However, intra-rater reliability between consecutive measurements of size, depth and shape was 0.221, 0.121, and 0.194, respectively, which showed only poor to fair agreement. Conclusions : Intra-rater and inter-rater reliability of one pulse wave showed relatively high concordance. Training by a clinical expert may effect better concordance among raters. Test-retest reliability showed poor agreement. Improvement of measurement technique and device performance will be needed.

비파괴 실험을 위한 모르타르의 전자기적 특성 측정 (Measurement of Electromagnetic Properties of Mortar for Nondestructive Testing)

  • 정성훈;임홍철
    • 한국콘크리트학회:학술대회논문집
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    • 한국콘크리트학회 1998년도 가을 학술발표대회 논문집(III)
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    • pp.779-784
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    • 1998
  • The velocity and amplitude of microwaves are affected by the electromagnetic properties of a material through which the wave propagates. And the electromagnetic properties of a dielectric material such as concrete is represented by its permittivity. For the development of an accurate and reliable nondestructive testing (NDT) technique for concrete structures using microwave, it is necessary to have knowledge about the permittivity of concrete. In this paper, mortar specimens are used to serve as a basis for further measurement of concrete. The effect of water on the permittivity was studied using specimens with different water content. To assure the reliability of the measurement results, a statistical method was introduced.

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압력센서를 이용한 디지털 콘크리트 공기량 시험기 개발에 관한 연구 (Study of Digital Air Meter Used Pressure Sensor for Air Content of Freshly Mixed Concretes)

  • 윤인준;이경문;서인호
    • 한국콘크리트학회:학술대회논문집
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    • 한국콘크리트학회 2006년도 춘계학술발표회 논문집(I)
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    • pp.566-569
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    • 2006
  • The purpose of this study is to develop digital air meter used pressure sensor for measurement of air content in freshly mixed concrete by pressure method. The digital air meter can enhanced measurement accuracy and uniformity of air content in freshly concretes, according to use of pressure sensor and measuring process automation. Finally, the digital air meter in this study is improved reproducibility and reliability of measurement compared with analog air meter.

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Measurement Uncertainty of Nicotine in Environmental Tobacco Smoke (ETS)

  • Lee, Jeong-Il;Lee, Cheol Min;Shim, In-Keun;Kim, Seong-Mi;Lee, Woo-Seok;Kim, Yoon-Shin
    • Bulletin of the Korean Chemical Society
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    • 제34권8호
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    • pp.2394-2398
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    • 2013
  • Nicotine is the main component of environmental tobacco smoke, and its presence in indoor air is widely used as a secondhand-smoke indicator. Environmental tobacco smoke is a major source of indoor air pollution, but sufficient investigation of the uncertainty of its measurement, which mirrors the reliability of nicotine measurement, has not been performed. We calculated the uncertainty of measurement of indoor air nicotine concentration at low, medium, and high concentrations of 11.3798, 10.1977, $98.3768{\mu}g/m^3$, respectively, and we employed the Guide to the Expression of Uncertainty in Measurements (GUM), proposed by the International Organization for Standardization (ISO). The factors considered in determining the uncertainty were uncertainty of the calibration curve (calibration curve and repeated measurements), desorption efficiency, extraction volume, and sampling airflow (accuracy and acceptable limits of flowmeter). The measurement uncertainty was highest at low concentrations; the expanded measurement uncertainty is $0.9435{\mu}g/m^3$ and is represented as a relative uncertainty of 63.38%. At medium and high (concentrations, the relative uncertainty was 13.1% and 9.1%, respectively. The uncertainty of the calibration curve was largest for low indoor nicotine concentrations. To increase reliability of measurement in assessing the effect of secondhand smoke, measures such as increasing the sample injection rate ($1{\mu}L$ or more), increasing sampling volume to increase collected nicotine, and using gas chromatography-mass spectrometry (GC/MS) or GC/MS/MS, which has a lower quantitation threshold, rather than gas chromatography with nitrogen phosphorous detector, should be considered.

PCS와 원칩 마이크로콘트롤러를 이용한 원격 검침 시스템 (Remote Measurement System with PCS and One Chip Microcontroller)

  • 이지홍;하인수;김인식
    • 대한전자공학회:학술대회논문집
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    • 대한전자공학회 2000년도 하계종합학술대회 논문집(5)
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    • pp.171-174
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    • 2000
  • In stead of RF module which has been used conventionally in many remote measurement applications, a new type of remote measurement system based on PCS(Personal communication system) and one chip Microcontroller is proposed in this work. PCS has many advantages with respect to cost reliability, communication quality, and so on. The proposed system consists of three different modules: PCS module, micro-controller module, and sensor module. System configuration as well as illustrative experiments will be described in detail.

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A STUDY ON A REGULAR EVALUATION METHODOLOGY OF STREAMFLOW DATA

  • Noh, Jae-Kyoung
    • Water Engineering Research
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    • 제1권3호
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    • pp.233-242
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    • 2000
  • A system for regularly appraising the reliability of streamflow data, KORSAS (KOwaco's Regular Streamflow Appraising System) was developed on PC based Windows for hydrological specialists and engineers working in the Korea Water Resources Corporation (KOWACO). The reliability of streamflow rates can be evaluated with KORSAS in various as pects according to the evaluation duration and method. The former being selected as short term (event based) or long term(continus based), and the latter being classified into comparison methods of flow measurement, other stations results, and simulation. Rainfall-runoff models can be used together with KORSAS in order to evaluate the reliability of observed flow data by comparing with simulated flow data. The objective of this study is to develop a systematic methodology in various aspects to evaluate the reliability of streamflow data regularly.

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지역난방 중온수 펌프의 현장 성능평가를 위한 열역학적 측정법 적용 (Aplication of the Thermodynamic Measurement Method for On-site Performance Evaluation of Hot Water Pumps Used in District Heating)

  • 박철규;유호선
    • 플랜트 저널
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    • 제17권1호
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    • pp.50-57
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    • 2021
  • 수력학적 효율측정 방법만으로는 펌프시스템 부속장치들의 개별효율 및 펌프 자체효율을 명확하게 산출해내기 매우 어렵다. 이에 본 연구에서는 국내 최초로 지역난방 중온수용 펌프시스템에 최신 열역학적 펌프 효율측정방법을 도입, 수력학적 방법과의 효율 병행측정 결과를 검토하였고, 그 결과 기존 수력학적 펌프효율 측정방법만으로는 데이터 불확실성이 높은 반면, 열역학적 및 수력학적 방법 병행측정 데이터를 적용한 펌프 및 유체커플링 효율값은 상호보완적 역할수행에 의해 펌프성능 측정방법의 신뢰성 및 적정성이 검증되는 의미 있는 결과를 도출할 수 있었다. 또한, 지역난방시스템에 열역학적 펌프효율 측정방법을 적용한 결과, 최대 120 ℃ 고온 환경에도 불구, 매우 안정적인 데이터 측정 및 측정장비의 내구성이 검증되는 등 열역학적 측정방법의 신뢰성을 검증할 수 있었다.

30 MHz에서 1 GHz 대역 EMI 측정용 다이폴안테나 교정의 측정 불확도 (Measurement Uncertainty for Calibration of EMI Dipole Antenna from 30 MHz to 1 GHz)

  • 박정규;정동찬;조진영
    • 한국전자파학회논문지
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    • 제18권2호
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    • pp.166-176
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    • 2007
  • 측정 분야나 교정 분야에서 측정 불확도를 보고하는 것은 매우 중요하다. 정보통신부 전파연구소에서는 EMI 측정 시험소를 위하여 안테나 교정 서비스를 제공하고 있는데, 안테나 교정의 정확성은 측정 불확도 평가로 집약되어, EMI 시험의 신뢰성을 판가름하는 시금석이 된다. EMI에 관한 국제기구인 CISPR에서는 2005년 말에 안테나 교정에 대한 최초의 표준 초안인 CISPR/A/644/C를 내놓았다. 이 초안은 안테나교정 및 관련된 측정 불확도를 포함하고 있다. 본 논문에서는 이 문서를 근간으로 전파연구소 이천의 안테나 교정시험장에서 EMI용 다이폴안테나를 교정할 때의 측정 불확도를 산출하였다. 전파연구소의 안테나 교정 방법은 자유 공간 안테나 인자를 측정하는 3-안테나의 height scanning averaging 법으로서, 본 방법에 의하여 안테나가 교정될 때 측정 결과에 영향을 미칠 수 있는 모든 불확도 요인을 고려하였다.

대전류 표준측정시스템에 대한 STL 최종방안의 소개 (The Introduction of the Final Proposal for the High-current Standard Measurement System)

  • 정주영;신영준;김익수;김민규;이정기;김맹현;이용한
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 2003년도 추계학술대회 논문집 전력기술부문
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    • pp.403-405
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    • 2003
  • 본 논문에서는 대전류 표준측정에 대한 STL TC의 Ad-Hoc Working Group의 최종방안에 대해 자세히 소개하여 이를 계기로 국내에서도 필요한 사전준비에 만전을 기하고자 한다. 향후 연속적으로 해야 할 업무, Shunt의 소유, 경비 지불방법 등에 대한 사항과 함께 우리나라 대전류 표준측정시스템의 구축절차를 제안하였으며, 이를 통해 대전류 측정에 있어서 국제표준과의 소급성을 확보할 수 있기 때문에 국내에서 시행하는 각종 시험에서 대전류 측정이 국제적으로 유효하게 될 것이다.

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대전류 표준측정시스템에 최종방안의 기술적 배경에 대한 고찰 (A Study on the Technical Background of the Final Proposal for the High-current Standard Measurement System)

  • 정주영;신영준;김익수;김민규;이정기;김맹현;이용한
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 2003년도 추계학술대회 논문집 전력기술부문
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    • pp.409-411
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    • 2003
  • 본 논문에서는 대전류 표준측정에 대한 STL TC의 Ad-Hoc Working Group의 최종방안에 대한 기술적 배경을 소개하여 이를 계기로 국내에서도 대전류 표준확보에 필요한 사전준비에 만전을 기하고자 한다. STL의 대전류 reference shunt 요구사항, 측정 불확도 및 각 시험소에서 교정하여야 할 사항 등에 대하여 검토하고, 우리나라 대전류 표준측정시스템의 구축필요성, 구축절차 및 방안에 대하여 기술한다.

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