• Title/Summary/Keyword: safety stock

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A Study on the Safety System Modeling to Prevent Train Accident by Turn-out Failure (분기기 고장 시 열차사고방지를 위한 안전시스템 모델링)

  • Yoo, Kwang-Kiun;Rho, Sung-Chan
    • Proceedings of the KSR Conference
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    • 2011.10a
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    • pp.724-730
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    • 2011
  • A turnout serves to switch train from one line to another. The turnout consists of a Point which is switchs the rail to induce direction, and a Crossing which is cross over two line on the plane surface, and a Lead where is middle section in Point to Crossing. Point machine, consists of a turnout, is important facilities in railway signal, that is safety issue relates in derailment of the train. Recently, train delay and accident frequently occurred because of the turnout include in a point machine trouble of electrical and mechanical. So in order to prevent train accident the research is advanced, install of normal and reverse indication lamp in a point machine, development of adherence detector for sensing the status of adhesion between the stock rails and tongue rails etc. In this paper investigates the problem which is connected with a turnout trouble, include in a point machine, occurrence at the time of train accident, and then proposed to the safety system model in order to prevent the train accident in turnout.

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On Study the Safety Diagnosis Assessment of EMU's Carbody (전동차의 구조체 안전진단평가 연구)

  • Chung Joog-Duk;Pyun Jang-Sik;Kim Jeong-Guk;Kim Won-kyung;Hong Yong-Ki
    • Proceedings of the KSR Conference
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    • 2004.06a
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    • pp.322-327
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    • 2004
  • This paper describes the structural analysis result of accident EMU(Electric Multiple Units). Structural analysis of EMU was performed for the criteria of safety assessment. Structural analysis using commercial I-DEAS software provided important information on the stress distribution and load transfer mechanisms as well as the amount of damages during rolling stock crash. Tensile tests were performed on two different types of specimens in order to evaluate the strength changes before and after damages, obtained from plastic deformed area and nondeformed region of the accident EMU. The structural analysis and tensile test results have been used to provide the critical information for the criteria of safety assessment.

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Bogie instability sensor using simulator for movement safety of the high speed train (고속열차 주행 안전성 시험을 위해 시뮬레이터로 구현한 대차 불안정 센서)

  • Choi, Kwon-Hee;Kim, Kuk-Jin;Lee, Byung-Won;Lee, Jong-Woo
    • Proceedings of the KSR Conference
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    • 2007.05a
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    • pp.1403-1407
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    • 2007
  • The bogie of Rolling Stock is the basic rolling component. It operates the train body, guides the body considering various tracks and offers comfort to passengers. We can verify the safety level of bogie about all factors through the first -grade scenario of Preliminary Hazard Analysis, but especially the horizontal acceleration sensor, equipped in each power bogie and trailer bogie, is the device, which makes it possible to test bogie instability and uncomfortable body movements by the method, similar to actual train driving, and in this context the necessity of this device becomes important. This paper would classify the main functions of driving sub system and examine the reliability, availability, maintainability and safety, which are main factors of RAMS. Especially, we would realize the bogie instability sensor with a simulator and offer the content in analyzing the data by the statistical method, which are obtained through the connected test with OBCS.

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Safety Stock for Desired Service Level for the Item with Probabilistic Demand (확률적 수요를 갖는 제품에서 서비스 수준을 고려한 안전재고 모형)

  • 서경범;박명규
    • Journal of the Korea Safety Management & Science
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    • v.2 no.3
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    • pp.81-88
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    • 2000
  • In this research, the system is assumed to carry a single item of which the demand types vary. Demand type is defined as a management's classification of the item according to the demand source or to the service purpose. The purpose of this research is to find the optimal inventory control policy when the system carries a single item which consists of multiple demand types. In this research, the optimizing algorithm contains a heuristic, therefore, the optimal is not guaranteed by the algorithm. At least, this research provides the solution to the problems that have not been solved by the existing algorithms.

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Safety Stock for Desired Service Level for the Item with Probabilistic Demand (확률적 수요를 갖는 제품에서 서비스 수준을 고려한 안전재고 모형)

  • 서경범;박명규
    • Proceedings of the Safety Management and Science Conference
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    • 2000.11a
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    • pp.127-130
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    • 2000
  • In this research, the system is assumed to carry a single item of which the demand types vary. Demand type is defined as a management's classification of the item according to the demand source or to the service purpose. The purpose of this research is to find the optimal inventory control policy when the system carries a single item which consists of multiple demand types. In this research, the optimizing algorithm contains a heuristic, therefore, the optimal Is not guaranteed by the algorithm. At least, this research provides the solution to the problems that have not been solved by the existing algorithms.

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The Study of Risk Acceptance Criteria for Railway System (철도시스템의 위험도 허용 기준 개발에 관한 연구)

  • Kim, Young-Sang;Maeng, Hee-Young;Wang, Jong-Bae
    • Proceedings of the KSR Conference
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    • 2008.06a
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    • pp.796-805
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    • 2008
  • Safety Management of Korean railway industry has been rapidly changed into a risk-based approach adopted by developed countries since Railway Safety Act 2004, Rolling Stock Risk Assessment Guidance and its following regulations came into force. The fundamental requirements for the risk-based safety management is to carry out a systematic hazard identification and quantified risk analyses including cost-benefit analyses, but there has been rare a serious discussion over risk acceptance criteria and value of life in order to be able to judge the results of risk analyses and carry out cost-benefit analyses. This study presents the results of a review of risk acceptance criteria and value of life which may be adoped to Korean railway industry through the analyses with comparison of risk accepatnce principles and risk accepatnce criteria which have been already applied to other countries or other railway operators.

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Structure Analysis of Wheel Set as Variation of Contact Position between Wheel and Rail (차륜과 레일의 접촉위치 변화에 따른 윤축의 구조해석)

  • Seo Byung-Wook;Ham Young-Sam;Hong Jai-Sung
    • Proceedings of the KSR Conference
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    • 2004.10a
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    • pp.606-610
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    • 2004
  • In this paper, we would like to explain about the structure analysis of wheel set as variation of contact position between wheel and rail. Measurement of interacted force between wheel and rail is necessary for running safety evaluation as important factor of derailment mechanism. It's necessary to running safety evaluation of rolling stock. Wheel unload and lateral force change as variation of contact position between wheel and rail. Interacted force between wheel and rail got as each contact position through computer simulation. This is necessary process as first research for evaluation of derailment phenomenon and running safety.

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A Study on Bayesian Reliability Evaluation of IPM using Simple Information (단순 수명정보를 이용한 IPM의 베이지안 신뢰도 평가 연구)

  • Jo, Dong Cheol;Koo, Jeong Seo
    • Journal of the Korean Society of Safety
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    • v.36 no.2
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    • pp.32-38
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    • 2021
  • This paper suggests an approach to evaluate the reliability of an intelligent power module with information deficiency of prior distribution and the characteristics of censored data through Bayesian statistics. This approach used a prior distribution of Bayesian statistics using the lifetime information provided by the manufacturer and compared and evaluated diffuse prior (vague prior) distributions. To overcome the computational complexity of Bayesian posterior distribution, it was computed with Gibbs sampling in the Monte Carlo simulation method. As a result, the standard deviation of the prior distribution developed using simple information was smaller than that of the posterior distribution calculated with the diffuse prior. In addition, it showed excellent error characteristics on RMSE compared with the Kaplan-Meier method.

The Building for Safety Regulation DB of Urban Transit System Infrastructure used by Computer Design Tool (전산지원도구를 이용한 도시철도시설 안전기준 DB구축 연구)

  • Lee, Woo-Dong;Shin, Jeong-Ryul;Ahn, Tai-Ki
    • Proceedings of the KSR Conference
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    • 2006.11b
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    • pp.786-790
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    • 2006
  • Urban rail transit offers target performance and function because various lower part system such as rolling-stock, signal, power and trackis consisted as complex. In order to function properly an urban rail transit which is complicated system to work as safety and reliability, System must secure safety with structure, design, manufacture, install and verification and it is important to establish a safety standard follows it procedures, establish what step all it is important to operate. Safety standard of urban transit infrastructure is minimum standard necessary to secure safety of signal, power and track. Urban rail transit standard business leads to make many requirements. Recently, many types of equipment have applied to manage requirements and standards for system efficiently in part of universal, airline and car accordingly applied equipments use to manage a pursuit(Trace) between standard of system. Especially importance of management is emphasized more become more. Importance of standard management which usesa computing support tool recently in transit filed is embossed and is predicted to be more such forward. Therefore we propose the effective method of management with infrastructure system by constructed data-base system.

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Detection of CTX-M Type ESBL Producing Salmonella in Retail Meat in Korea

  • Kim, Yong Hoon;Joo, In Sun;Kim, Yoon Jeong;Oh, Mi Hyun;Cho, Joon Il;Han, Min Kyong;Kim, Soon Han;Moon, Tae Wha;Park, Kun Sang
    • Journal of Food Hygiene and Safety
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    • v.29 no.1
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    • pp.47-52
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    • 2014
  • This study was performed to evaluate antimicrobial resistance of food-borne pathogens isolated from retail meat in Korea. A total of 157 samples of beef, pork, and chicken were collected and analyzed for E. coli, Salmonella, Campylobacter. Resistances to tetracycline were declined in accord with reduced usage of tetracycline in live stock production. E. coli stains from chicken meat had higher multi-drug resistance ratio than strains from other meat. One extended spectrum beta lactamase (ESBL) producing E. coli and two ESBL producing Salmonella were identified in this study. ESBL producing Salmonella strains were confirmed to carry CTX-M-1 type genes.