• Title/Summary/Keyword: safety limits

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계량 규준형 샘플링 검사 스킴을 이용한 합격판정 관리도의 설계 및 운영 (Design and Operation of Acceptance Control Chart Using Variable Acceptance Sampling Scheme Based on Operating Characteristics(OC) Curve)

  • 최성운
    • 대한안전경영과학회:학술대회논문집
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    • 대한안전경영과학회 2008년도 춘계학술대회
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    • pp.443-450
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    • 2008
  • This paper is to present design principle and operation strategy of acceptance control chart by the use of OC-Based sampling inspection for continuous data. The unified control limits for acceptance control chart when considering both APL(Acceptable Process Level) and RPL(Rejectable Process Level) are proposed. The control limits can be also extended to the acceptance control chart with unknown process standard deviation.

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도시부도로 제한속도 산정모형 개발 및 효과분석 연구 (Development of Speed Limits Estimation Model and Analysis of Effects in Urban Roads)

  • 강순양;이수범;임준범
    • 한국안전학회지
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    • 제32권2호
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    • pp.132-146
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    • 2017
  • Appropriate speed limits at a reasonable level in urban roads are highly important factors for efficient and safe movement. Thus, it is greatly necessary to develop the objective models or methodology based on engineering study considering factors such as traffic accident rates, roadside development levels, and roadway geometry characteristics etc. The purpose of this study is to develop the estimate model of appropriate speed limits at each road sections in urban roads using traffic information big data and field specific data and to review the effects of accident decrease. In this study, the estimate method of appropriate speed limits in directional two or more lanes of urban roads is reflecting features of actual variables in a form of adjustment factor on the basis of the maximum statutory speed limits. As a result of investigating and testing influential variables, the main variables to affect the operating speed are the function of road, the existence of median, the width of lane, the number of traffic entrance/exit path and the number of traffic signal or nonsignal at intersection and crosswalk. As a result of testing this model, when the differences are bigger between the real operating speed and the recommended speed limits using model developed in this study, the accident rate generally turns out to be higher. In case of using the model proposed in this study, it means accident rate can be lower. When the result of this study is applied, the speed limits of directional two or more lane roads in Seoul appears about 11km/h lower than the current speed limits. The decrease of average operating speed caused by the decrease of speed limits is 2.8km/h, and the decrease effect of whole accidents according to the decrease of speed is 18% at research road. In case that accident severity is considered, the accident decrease effects are expected to 17~24% in fatalities, 11~17% in seriously injured road user, 6~9% in slightly injured road user, 5~6% in property damage only accidents.

가연성가스와 증기의 폭굉한계 예측 (Prediction of the Detonation Limit of the Flammable Gas and Vapor)

  • 하동명;유현식;강석환;박동진;정진용;이명호;최원영;한승희
    • 한국화재소방학회:학술대회논문집
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    • 한국화재소방학회 2008년도 춘계학술논문발표회 논문집
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    • pp.131-134
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    • 2008
  • 본 연구에서는 가연성혼합물의 구성하는 각 순수성분의 연소열과 기상 조성을 이용하여 폭발한계를 예측하였다. 제시된 방법론에 의한 계산값은 적은 오차범위에서 문헌값과 일치하였다. 따라서 제시된 결과로부터 제시된 방법론이 다른 가연성혼합물의 폭굉한계 예측에 폭넓게 적용되기를 기대한다.

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소음 노출 사업장의 소음 노출수준과 노출기준 초과율 현황 (Noise Exposure Levels of Workplaces Exposed to Noise and Rate of Exceedance of Exposure Limits)

  • 김규상;성정민;김은아
    • 한국산업보건학회지
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    • 제30권2호
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    • pp.185-195
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    • 2020
  • Objectives: The purpose of this study was to analyze noise exposure levels and the rate of exceedance of exposure limits in workplaces from a 2015 measurement of working environments according to area, industry, and scale of workplace and to determine changes compared to the past. Methods: Among the 408,875 measurements of noise in working environments from 27,030 workplaces in 2015, 16,359 workplaces that were linked to special health examination data were selected as the subjects of this study. The eight-hour corrected measurements and geometric mean values of the individual noise measurements of the workplaces were used to calculate noise exposure levels and the exceedance rate of exposure limits. Results: The average noise exposure level of the overall workplaces making up the subjects of this study was 83.6 dBA, and the exceedance rate of exposure limits was 15.1%. At least half of the noise measurements exceeded the exposure limits in 13.7% of the workplaces. Noise exposure levels were higher in the manufacturing industry and in smaller-scale workplaces. The exceedance rate of noise exposure limits was higher in the mining and manufacturing industries and in smaller-scale workplaces. Conclusions: Noise exposure has shown improvements compared to the past, but the exceedance rate of exposure limits was still high, and more than half of the workers were being exposed to noise of 85 dBA or higher. Therefore, it is necessary to make more active improvements in working environments in terms of noise exposure.

농약사용에서의 잔류기준 설정과 GAP (Establishing residue limits and GAP in the use of pesticides)

  • 이서래
    • 농약과학회지
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    • 제9권2호
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    • pp.113-121
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    • 2005
  • 국가차원에서 식품안전 프로그램은 소비자보호와 식인성질환의 예방을 기본요소로 하고 있으며 정부, 식품산업, 소비자가 책임질 일이다. 여기에서는 WHO에서 제안하고 있는 식품안전 프로그램의 원칙을 소개한 다음 식품생산에 사용되는 의도적 첨가물의 잔류기준 설정에서 GAP의 중요성, 국제기구와 국내에서 잔류농약의 기준설정에 활용되고 있는 절차와 차이점을 지적하였다. 결론적으로 잔류농약에 대한 국내기준을 Codex 기준과 조화시키는데 필요한 사항들을 건의하였다.

시운전 시험을 통한 한국형 고속전철 차체진동 특성의 분석 및 평가 (Analysis and Evaluation of Body Vibration Characteristics for Korean High Speed Train through On-line Test)

  • 김영국;김석원;박찬경;김기환;목진용
    • 한국철도학회논문집
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    • 제6권4호
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    • pp.286-293
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    • 2003
  • The prototype of Korean high speed train (HSR350), composed of two power cars, two motorized cars and three trailer cars, has been designed, fabricated and tested. In this paper, the body vibration has been reviewed from the viewpoint of the vehicle's safety and the vibration limits for components and sub-assemblies mounted on the car-body using by the experimental method. And, the dynamic characteristics, such as jerk, natural mode and kinematic mode, have been reviewed. The KHST has been run to 300 km/h in the KTX line and the results of on-line test show that it has no problems in the vehicle's safety and the vibration limits. And the characteristics of body vibrations has been predicted at 350 km/h by fitting curve about the measured acceleration signals.

파라크실렌과 에폭시수지 혼합물의 인화점에 관한 연구 (Flash Point of p-xylene and Epoxy Resins Mixtures)

  • 윤희승;강민호;하동명;정국삼
    • 한국안전학회지
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    • 제15권3호
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    • pp.78-82
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    • 2000
  • The flash point is an important property and hazardous index of a flammable liquid. The flash points are used by virtually all the environmental, health, and safety organizations in both government and industry to classify flammable liquids for safety and transportation regulations. The basics of all flash points behavior are concerned with the vapor pressure and explosive limits. The flash points of pure components and the mixture of solvents can be calculated with the use of the laws of Raoult, Dalton and Le Chatelier. In this paper, experimentally determined lower flash points of a p-xylene and epoxy resin system were compared with the calculated values by using Raoults law. Calculated lower flash points were in reasonable agreement with the observed values.

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에스테르화합물에 대한 표준끓는점과 인화점을 이용한 폭발하한계 추산 (Estimation of the Lower Explosion Limits Using the Normal Boiling Points and the Flash Points for the Ester Compounds)

  • 하동명
    • 한국안전학회지
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    • 제22권5호
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    • pp.84-89
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    • 2007
  • 폭발하한계는 가연성물질의 화재 및 폭발 위험성을 결정하는데 사용되는 중요한 연소특성치의 하나이다. 본 연구에서 에스테르 화합물에 대한 폭발하한계는 액체 열역학이론을 근거로 표준끓는점과 인화점을 이용하여 예측하였다. 그 결과, 문헌값과 예측값의 A.A.P.E.(average absolute percent error)는 8.80vo1%이고, A.A.D.(average absolute deviation)는 0.18vo1% 그리고 상관계수는 0.965로써 문헌값과 예측값은 일치하였다. 제시된 방법론 사용에 의해 다른 가연성물질의 폭발하한계 예측이 가능하다.

페놀의 연소특성치의 측정 및 예측 (Measurement and Prediction of Combustion Properties of n-Phenol)

  • 하동명
    • 한국위험물학회지
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    • 제6권2호
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    • pp.23-29
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    • 2018
  • The fire and explosion properties necessary for waste, safe storage, transport, process design and operation of handling flammable substances are lower explosion limits(LEL), upper explosion limits(UEL), flash point, AIT( minimum autoignition temperature or spontaneous ignition temperature), fire point etc., An accurate knowledge of the combustion properties is important in developing appropriate prevention and control measures fire and explosion protection in chemical plants. In order to know the accuracy of data in MSDSs(material safety data sheets), the flash point of phenol was measured by Setaflash, Pensky-Martens, Tag, and Cleveland testers. And the AIT of phenol was measured by ASTM 659E apparatus. The explosion limits of phenol was investigated in the reference data. The flash point of phenol by using Setaflash and Pensky-Martens closed-cup testers were experimented at $75^{\circ}C$ and $81^{\circ}C$, respectively. The flash points of phenol by Tag and Cleveland open cup testers were experimented at $82^{\circ}C$ and $89^{\circ}C$, respectively. The AIT of phenol was experimented at $589^{\circ}C$. The LEL and UEL calculated by using Setaflash lower and upper flash point value were calculated as 1.36vol% and 8.67vol%, respectively. By using the relationship between the spontaneous ignition temperature and the ignition delay time proposed, it is possible to predict the ignition delay time at different temperatures in the handling process of phenol.