• Title/Summary/Keyword: method of measurement

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An Integrated Approach to Measuring Supply Chain Performance

  • Theeranuphattana, Adisak;Tang, John C.S.;Khang, Do Ba
    • Industrial Engineering and Management Systems
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    • 제11권1호
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    • pp.54-69
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    • 2012
  • Chan and Qi (SCM 8/3 (2003) 209) developed an innovative measurement method that aggregates performance measures in a supply chain into an overall performance index. The method is useful and makes a significant contribution to supply chain management. Nevertheless, it can be cumbersome in computation due to its highly complex algorithmic fuzzy model. In aggregating the performance information, weights used by Chan and Qi-which aim to address the imprecision of human judgments-are incompatible with weights in additive models. Furthermore, the default assumption of linearity of its scoring procedure could lead to an inaccurate assessment of the overall performance. This paper addresses these limitations by developing an alternative measurement that takes care of the above. This research integrates three different approaches to multiple criteria decision analysis (MCDA)-the multiattribute value theory (MAVT), the swing weighting method and the eigenvector procedure-to develop a comprehensive assessment of supply chain performance. One case study is presented to demonstrate the measurement of the proposed method. The performance model used in the case study relies on the Supply Chain Operations Reference (SCOR) model level 1. With this measurement method, supply chain managers can easily benchmark the performance of the whole system, and then analyze the effectiveness and efficiency of the supply chain.

게이지 R&R 연구에서 근사 F검정과 EMS를 이용한 측정 정밀도의 평가 (Evaluation of Measurement Precisions Using Approximate F Tests and EMS in the Gauge R&R Studies)

  • 최성운
    • 대한안전경영과학회지
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    • 제11권3호
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    • pp.209-216
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    • 2009
  • A development in method of evaluating the measurement precisions using approximate F tests and variance components from expected mean square (EMS) is investigated. The research proposes three-factor mixed measurement models with the fixed and random factors. Unrestricted and unconstrained design work was rarely studied, while restricted and constrained designs have been significantly discussed. The unrestricted and unconstrained designs assume to be an independence of interaction. The proposed evaluation method about the measurement precisions can be extended to four-factor random measurement model or mixed measurement model. The study also presents the three evaluation indexes of precisions such as R&RTR (Reproducibility & Repeatability-To-Total Precision Ratio), PTR (Precision-To-Tolerance Ratio), and SNR (Signal-To-Noise Ratio). Numerical examples are proposed to evaluate the approximate F tests with Satterthwaite degrees of freedom and three indexes using the measurement precisions from EMS.

악취관리제도의 국가간 비교연구 (A Comparative Study for Odor Control Regulations)

  • 양성봉;김석만
    • 한국대기환경학회지
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    • 제16권1호
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    • pp.79-87
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    • 2000
  • This study analyzed the regulations concerning odor management or control in Korea, Japan, and developed countries such as USA and Germany. The Korean restriction standards and measurement methods for offensive odor substances are very similar to the Japanese standards and methods promulgated in 1976. Japan promulgated the odor control act and the specific measurement methods of the offensive odor substances in 1973. In Japan, currently, the local governments can establish their own odor restriction areas and proclaim their own standards suitable for their situations. Also, Japan has more strict regulations and more offensive odor substances to be monitored than Korea. The restriction standards of odor in German is quite similar to the permissible limits and standards of air pollutants at emission sources in Korea. Many states in USA are adopting their own restriction standards and measurement methods, e.q., the ambient air pollution standards, organic functionstest methods by dilation, and establishment and addition of air pollution control equipment at emission sources. Finally, this study analyzed the problems of the regulations, standards, and measurement methods concerning the Korean offensive odor management. Since the direct organic fuctions measurement(DOFMM) method is depending upon the personal sensitives of odor substances, the measurement odor value can be equivocal. That is, the odor measurement value by an examines can differ from that by the other examines. Also, there can be conflicts with the measured odor values depending upon the applied measurement methods, e.q., the DOFMM, the dilation method, and the instrumental analysis method.

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영상처리에 의한 경량기포 콘크리트 블록의 치수측정 및 불량경사 알고리즘 개발 (Development of Size Measurement and Inspection Algorithm for Autoclaves Lightweight Concrete Block by Image Processing)

  • 김성훈;허경무
    • 전자공학회논문지CI
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    • 제40권4호
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    • pp.206-213
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    • 2003
  • 본 논문에서는 고성능의 하드웨어 장비가 아닌 일반적으로 사용되는 개인용 컴퓨터와 CCD 카메라를 이용하여 자동으로 경량기포 콘크리트(autoclaved lightweight concrete) 블록간의 상하 경사도, 두께의 불균일성, 그리고 불량 여부를 판별할 수 있는 알고리즘을 제안하였다. 제안한 치수측정 및 불량검사 자동화 알고리즘은 실제 작업환경을 고려하여 일반적인 조명조건에서의 전처리과정과 작업공정내의 피사체의 진동을 고려한 단위길이 결정방법, 카메라의 곡률보정에 의한 치수오차 보정 방법 등을 적용하였으며, 실제공정에서의 실험 결과를 통해 블록군의 계측에 있어서 0.8초 이내에 측정오차 1%이내의 데이터를 산출해 냄으로서 제안한 불량검사 자동화시스템의 신뢰성을 검증할 수 있었다.

DC링크 전류센서를 이용한 삼상전류 측정 방식에서 최소 스위칭 시간의 단축 (Reduction of Minimum Switching Duration in the Measurement of Three Phase Current with DC-Link Current Sensor)

  • 김경서
    • 대한전기학회논문지:전기기기및에너지변환시스템부문B
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    • 제52권12호
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    • pp.649-654
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    • 2003
  • The simplest method for measuring output currents of the three phase inverters is to measure them with three current sensors such as hall sensors. This method requires at least two current sensors, and these types of sensors are somewhat expensive. More economical method is measuring DC link current with a simple shunt resistor, then, reconstructing output current using the DC link current value and the switching status. However, in low speed region, the measurement becomes difficult and even impossible due to the requirement of minimum switching duration for A/D conversion. These problems can be overcome by limitation of switching duration. Limitation of switching, however, causes voltage and current distortion. Owing to compensation, distortion can be effectively suppressed. However these increase acoustic noise due to increment of current ripple. In this paper, a current measurement method is proposed, which can reduce minimum switching duration resulting in reduction of acoustic noise. The validity of proposed method is confirmed through experiment.

원격자료수신장비 소형반사판 안테나 G/T 예측 및 측정 (The calculation and Measurement Methods for G/T of the Telemetry Small Aperture Antenna)

  • 김춘원;안나균;김동현;조병록
    • 한국항공우주학회지
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    • 제50권9호
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    • pp.657-662
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    • 2022
  • 본 논문에서는 나로우주센터에서 운용 중인 원격자료수신장비의 G/T에 대한 시뮬레이션 활용 계산 결과와 측정 방법 2개에 대하여 분석하였다. 안테나 이득과 잡음 온도는 ICARA와 Antenna Noise Temperature Calculator를 이용하여 계산하였다. 시스템 G/T는 안테나 이득/잡음돈도와 LNA 이득/잡음온도, 케이블 손실을 반영하여 산출하였다. 첫 번째 G/T 측정 방법은 Y팩터 측정법으로 LNA 입력단에 안테나와 50ohm 터미네이션을 각각 연결했을 때의 신호 레벨 차이값을 LNA 열잡음 온도와 비교하여 G/T를 산출하는 방법이다. 두 번째 방법은 태양과 최저 레벨 지점을 바라보았을 때의 잡음 레벨 값 차이를 비교하여 G/T를 구하는 Solar Calibration 측정법이다. 마지막으로 G/T 계산결과와 두 측정법 비교를 통해 정확성을 검토하고 이로부터 안테나 성능, 운용환경에 따른 최적 측정법을 제시하였다.

Development of automatic measurement method of concentricity and roundness using image processing technique

  • Moon, Hyung-Wook;Huh, Kyung-Moo
    • 제어로봇시스템학회:학술대회논문집
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    • 제어로봇시스템학회 2001년도 ICCAS
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    • pp.130.2-130
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    • 2001
  • In this paper, we suggest an algorithm for the automatic measurement of concentricity and roundness using image processing technique. From the experimental results, we could find that the required measurement accuracy specification is sufficiently satisfied using our proposed method.

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수소연료전지자동차 연료소비율 측정방법에 대한 연구 (Development of Fuel Economy Measurement Method for Hydrogen Fuel Cell Vehicles)

  • 임종순;최영태;용기중;권해붕;이현우;맹정열
    • 한국신재생에너지학회:학술대회논문집
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    • 한국신재생에너지학회 2009년도 춘계학술대회 논문집
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    • pp.636-639
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    • 2009
  • Fuel consumption measurement of Hydrogen fuel cell vehicle is considerably different form internal combustion engine vehicle such as carbon balance method. A practical method of fuel Consumption measurement has been developed for Hydrogen fuel cell vehicles. There are three method of hydrogen fuel consumption testing, gravimetric, PVT(Pressure, Volume and temperature), and Coriolis mass flow, all of which necessitate physical measurements of the fuel supply. The purpose of this research is to measure the fuel consumption of hydrogen fuel cell vehicles on chassis-dynamometer and to give information when the research is intended to develop method to measure hydrogen fuel consumption.

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양의 측정을 통한 자연수와 분수 지도의 교수학적 의의 (The Educational Significance of the Method of Teaching Natural and Fractional Numbers by Measurement of Quantity)

  • 강흥규;고정화
    • 대한수학교육학회지:학교수학
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    • 제5권3호
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    • pp.385-399
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    • 2003
  • 현재 우리 나라 수학 초등학교 교육과정에서 자연수는 측정과 무관한 일대일 대응 조작이나 수세기를 통하여 지도되고 있으며 분수는 측정이 부분적으로 개재된 방식으로 지도되고 있다. 이러한 지도 방식의 가장 큰 문제점은 자연수와 분수가 분리된다는 점이다. 이러한 문제점을 극복하고자 양의 측정을 통하여 자연수와 분수를 가르칠 것을 주장한 대표적인 인물이 Dewey와 Davydov이다. 이 논문에서는 Dewey와 Davydov의 주장에 근거하여 양의 측정을 통한 자연수와 분수 지도 방법을 개략적으로 제시하였고, 그것과 현재 우리나라 교육과정에서 자연수와 분수를 지도하는 방법과의 차이점을 고찰하였다. 이를 토대로 양의 측정을 통한 자연수와 분수 지도 방법의 교수학적 의의를 다음과 같이 파악하였다. 첫째, 양의 측정활동으로부터 자연수와 분수 개념이 분화된다. 둘째, 자연수에서 분수로의 전이과정이 필연성을 띤다. 셋째, 자연수와 분수 그리고 그것들의 하위 분야가 긴밀하게 연결된다.

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선형홀센서를 이용한 전기식 구동장치의 속도 신호 구현 (A New Velocity Measurement Method using Linear Type Hall-effect Sensor for Electro-mechanical Fin Actuator)

  • 구정회;송치영
    • 전기학회논문지
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    • 제59권1호
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    • pp.70-75
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    • 2010
  • The objective of this paper is to propose a new velocity measurement method for an electro-mechanical fin actuator. The model of the electro-mechanical fin actuator includes uncertainties such as unknown disturbances and parameter variations in flight condition. So, an electro-mechanical fin actuator system needs robust control algorithm which requires not only position information but also velocity information. Usually, analog tachometers have been used for velocity feedback in an electro-mechanical fin actuator. However, using these types of sensors have problems such as the cost, space, and malfunction. These problems lead to propose a new velocity measurement method using linear type Hall-effect sensor. In order to verify the proposed method, several experiments are performed using Model Following Sliding Mode Controller(MFSMC). It is shown that the MFSMC with a new velocity measurement method using linear type Hall-effect sensor can satisfy the requirements without using of velocity sensor.