• Title/Summary/Keyword: Uncertainly of Measurement

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Uncertainty of Measurements in the Analysis of Vehicle Accidents (차량 사고 분석에서 측정의 불확실성)

  • Han, In-Hwan;Park, Seung-Beom
    • Journal of Korean Society of Transportation
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    • v.28 no.3
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    • pp.119-130
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    • 2010
  • Reconstruction analysis of traffic accident is done by analyzing diverse data such as the road, accident traces and damage on the automobile. Most data can be a variable in the process of analysis, and measurement error of the data occurs from the investigator, tool and the given environment. Therefore, accident analysis always has some risks of measurement uncertainty. This research quantify the uncertainty in traffic accident analysis by conducting repetitive measurement experiments for variables with high probability of uncertainly such as length (i.e. geometric structure of the road, tire marks) and coefficient of friction. This paper also suggests an analysis result for the uncertainly of photographic observation of automobile crush measurement. These statistical distributions can help determine appropriate ranges for the input data in order to estimate the accident reconstruction uncertainty.

Improvement of size measurement polystyrene spheres of diameters 3$\mu$m and 10$\mu$m by optical microscope with CCD camera (CCD 카메라가 장착된 광학현미경을 사용한 폴리스티렌구 (3 $\mu$m와 10 $\mu$m)의 평균지름측정)

  • 정기영;박병천;깅주식;송원영;오범환
    • Korean Journal of Optics and Photonics
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    • v.9 no.6
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    • pp.362-367
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    • 1998
  • Center Distance Finding (CDF) is a technique to find the sphere diameter by measuring the distance between two contacting spheres. The focal spots of the sphere clusters are formed in the back-focal plane by the transmission-mode optical microscope with the pseudothermal illumination source. Digital images taken by the CCD camera were processed by the software called Global Lab Image. The centers of the focal spots are found and the spot positions are expressed in terms of the CCD pixel elements, whose coordinate are calibrated by a heterodyne interferometer. The new CDF measurement system has been developed, which are more advantageous in time and convenience than the existing system, while the measurement uncertainly remains sufficient for its use as a magnification standard for optical microscopy. Two kinds of polystyrene spheres whose nominal diameters 3 and 10 $\mu\textrm{m}$ (NIST SRM 1962 and 1960) are measured with the uncertainly less than 1% at the confidence level of 99%, and the results are compared with the results of National Institute of Standards and Technology.

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A Study Fuzzy model for Risk Analysis of Uncertainly FTA(Fault Tree Analysis) (FTA(Fault Tree Analysis)에서 불확실한 위험분석을 위한 퍼지모형 연구)

  • 임총규;박주식;강경식
    • Journal of the Korea Safety Management & Science
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    • v.4 no.1
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    • pp.37-47
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    • 2002
  • Risk analysis is a formal deductive procedure for determining combinations of component failures and human errors that could result in the occurrence of specified undesired events at the system level. This method can be used to analyze the vast majority of industrial system reliability problems. This study deals with the application of knowledge-engineering and a methodology for the assessment & measurement of reliability, availability, maintainability, and safety of industrial systems using FTA(fault tree analysis), A fuzzy methodology for fault-tree evaluation seems to be an alternative solution to overcome the drawbacks of the conventional approach (insufficient Information concerning the relative frequencies of hazard events). To improve the quality of results, the membership functions must be approximated based on heuristic considerations, The purpose of this study is to describe the knowledge engineering approach, directed to integrate the various sources of knowledge involved in a FTA.

The verification of Luminous flux of Reference illuminant for New light source by the calculated correction factor (보정계수 산출에 의한 신광원용 표준램프 광속의 검증)

  • Hwang, Myung-Keun;Shin, Sang-Wuk;Yi, Chin-Woo
    • The Transactions of The Korean Institute of Electrical Engineers
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    • v.58 no.2
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    • pp.369-372
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    • 2009
  • When measuring the luminous flux of a light source at the integrating sphere photometer, it can know the luminous flux to compare the standard lamp with the specimen lamp at the same location. But in case of PLS(plasma lighting system, microwave discharged lamp), that two lamps are cannot be the same location. If the reference illuminant and specimen lamp are cannot measure identical location, we should measure the variation of the luminous flux. For the outcome we can turn out a correction factor to revise and reflect it. But the better way is calibrate the specimen lamp locate the identical location of reference illuminant measured. In this thesis, we've test to find the correction factor for consider that change the measuring location. And it turns out the correction factor. From this, it presents the result to make a select for the reference illuminant which is against the illuminant type for newly produce.