• 제목/요약/키워드: safety stock

검색결과 330건 처리시간 0.031초

공항철도의 운영가용도 향상을 위한 RCM 활동 (RCM Activities for Improvement of Availability of AREX Railway System)

  • 이창환;임성수;송미옥
    • 한국철도학회:학술대회논문집
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    • 한국철도학회 2008년도 춘계학술대회 논문집
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    • pp.742-747
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    • 2008
  • This paper is described the systematic activities of RCM to improve the availability for AREX railway system. The purpose of these activities are to maintain and enhance the reliability, availability, maintainability and safety, and to implement the effective maintenance for electrical and mechanical system including rolling stock, signalling, telecommunication, power supply, overhead catenary and platform screen door with impact to train operation.. The main activities consist of systematic failure and repair recording by integral information system, analysis and corresponding countermeasure. As applying these activities in opeartion and maintenance works, the availability of AREX railway system is going on improvement gradually, and maintenacne works are improved with these results.

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전압제어형 센서를 이용한 스마트 콘크리트의 개발 (Development of the Smart Concrete Using the Voltage Control Type Sensor)

  • 김이성;이수곤;김화중
    • 한국콘크리트학회:학술대회논문집
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    • 한국콘크리트학회 2005년도 봄학술 발표회 논문집(II)
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    • pp.169-172
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    • 2005
  • Today, peoples have much interest about safety while an abnormal weather phenomenon is weighted increased. R.C buildings are consisting of main loaded members. Concrete are brittle materials and they are which come to brittle fracture rapidly by progress of cracks. With the exchange of such research in inside and outside of the country, the structure measurement method of having used PZT and the optical fiber (FBG) will be the actual condition which has accomplished the stock. Specially, seismic activity that gives damage to construction and members happens in on time. Therefore, the purpose of this study is the fundamental research which detects damagesof main members using the compound sensor which consisted of the radio sensors of resistance, PZT, and FM system.

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부재고를 갖는 재고.수송시스템의 최적모형설계 (A Design for Optimal Models of Inventory-Distribution System with Back-Ordered Case)

  • 우태희;조남호
    • 산업경영시스템학회지
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    • 제20권43호
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    • pp.25-36
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    • 1997
  • The purpose of this paper is to structure a new integrated model that can minimize the total cost for the transportation and inventory systems between m origin points, where origin i has a supply of a commodity, such as distribution centers or warehouses, and n destination points, where destination j requires the commodity. In this case, demands of the destination points are assumed random variables which have a known probability distribution. We will find optimal distribution centers which transport the commodity to the destination points and suggest optimal inventory policy to the selected distribution center which find the optimal pair $$ and safety stock level that minimize total cost with back-ordered case. This new model is formulated as a 0-1 nonlinear integer programming problem. To solve the problem, this paper proposes heuristic computational procedures and program and provides numerical examples.

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철도차량 유지보수 체계 구축 (Establishment of the maintenance system for rolling stock)

  • 이명호;이현종;권정원
    • 한국철도학회:학술대회논문집
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    • 한국철도학회 2002년도 추계학술대회 논문집(I)
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    • pp.408-413
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    • 2002
  • From the moment that electricity is applied to a relay, a wheel turned, or a valve opened, the process leading to the need for maintenance begins, The uninitiated will tell you that the Maintenance man is someone who repairs something when it has gone wrong. Unfortunately, in any large engineering concern, such as a railway, it is not possible to work on the principle that only when something breaks down should it get any attention. The failure of one contact, diode or bearing could well stop not only the assembly of which it is a part, but the flow line or process, with loss of revenue, and clientele, and often with effects on the safety of both staff and the traveling public. So, we have to establish the reliable and cost-effective maintenance system to resolve these problems.

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차세대 차상신호장치용 MMI 고찰 (The Study of Man-Machine Interface device for New On-board ATC/ATO Equipment)

  • 유영준;박종천;강리택;조영완;차기주
    • 한국철도학회:학술대회논문집
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    • 한국철도학회 2006년도 추계학술대회 논문집
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    • pp.731-735
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    • 2006
  • The Rolling Stock pursues more safe, speedy and accurate operation on the increment of the passenger and the short headway. Signalling system is providing an assurance on safety and reliability of the system, which is based on fail-safe concept. Therefore we are willing to study up on MMI device for new onboard ATP/ATO equipment which is used for driver to recognize train status and fault more quickly and to solve any problem more rapidly, which can maximize the stability and reliability of the system.

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차량신호를 이용한 주요 전장품의 고장 분석 (Fault Analysis of Electric Equipment Using Vehicle Signal)

  • 한영재;김기환;김상수;이병석;정상훈;조병찬
    • 한국철도학회:학술대회논문집
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    • 한국철도학회 2006년도 추계학술대회 논문집
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    • pp.1488-1494
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    • 2006
  • The most important thing to secure safety and reliability of railway vehicles is to verify performance characteristics of equipments, and related companies or research institutes had many efforts to verify performances and functions of equipments synthetically and efficiently. KHST(Korean High Speed Train) has been developed by KRRI(Korea Railroad Research Institute). An electric railway system is composed of high-tech subsystems, among which main electric equipment such as transformers and converter are critical components determining the performance of rolling stock. We developed a measurement system for on-line test and evaluation of performances of KHST. The measurement system is composed of software part and hardware part. Perfect interface between multi-users is possible. A new method to measure temperature was applied to the measurement system. By using the system, fault diagnosis and performance evaluation of electric equipment in Korean High Speed Train was conducted during test running.

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전동차 수명 주기 비용에 대한 고찰 (Investigation into Life Cycle Cost of Electric Multiple Unit (EMU))

  • 박종목;김필환;이종권
    • 한국철도학회:학술대회논문집
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    • 한국철도학회 2002년도 추계학술대회 논문집(I)
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    • pp.396-407
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    • 2002
  • 신규로 투입되는 전동차는 강화된 안전성과 승객 편의성 규격이 요구되며 이로 인해 차량 초기 구입 비용 증가가 불가피할 것으로 예상되나 효율적인 설계를 통한 운영비 절감 등 또한 예상된다. 따라서 차량 구입은 초기 구입 비용, 운영 비용을 고려하여 결정되어야 하며, 이러한 비용 추정의 한 방법으로써 차량 수명 주기 비용(Life Cycle)과 그 적용 가능성을 제시하고자 한다.

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Inventory Management Practices Approach to Reverse Logistics

  • Wang, Dja-Shin;Koo, Tong-Yuan
    • Industrial Engineering and Management Systems
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    • 제9권4호
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    • pp.303-311
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    • 2010
  • In the last few years growing interest has been dedicated to supply chain management. Modeling complexity is added to supply chain coordination problem by accounting for reverse logistics activities. The objective of this paper is to extend inventory model of manufacturing factory with respect to the production of raw material of forward logistics and recycling material of reverse logistics. The proposed model is applied to a plastic recycling process plant located in Taiwan. The case study improvement scheme shows when the recycling rate of recycling material increases from 15% to 50%, the total inventory cost of manufacturing factory decreases by 12.82%, safety stock volume decreases by 41.19% and the reorder quantity is down by 50.96%. This paper finds whether the results of the model can reach the economic profit through quantitative analysis and encourages companies integrate reverse logistics into the supply chain system.

벡터제어 유도전동기를 이용한 축소형 관성 시뮬레이터 (A Miniature Inertia Simulator using Vector Controlled Induction Motor)

  • 김길동;박현준;한영재;한경희;조정민
    • 전력전자학회논문지
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    • 제7권1호
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    • pp.74-80
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    • 2002
  • 철도차량용 추진시스템은 안전성과 신뢰성 때문에 성능을 평가해야만 한다. 일반적으로 Flywheel Type시험방법은 시험설비로 널리 사용되고 있다 그러나 Flywheel에 의해 생기는 기계적 관성은 변하기 어렵고 실제적인 주행저항을 표현할 수 없다. 본 연구는 다양한 차량부하의 개발에 초점을 두고 수행되었다. 그렇기 때문에 실제적인 차량 부하 특성을 얻기 위해 벡터모터에 의해 제어되는 다양한 차량부하를 사용하는 방법을 제안하였고 컴퓨터 시뮬레이션을 통해 결과를 확인하였다.

도시철도 차량시스템 요구사항체계 구축방안에 관한 연구 (The Propose to the System Requirement Structure of Rolling Stock System)

  • 이우동
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 2005년도 추계학술대회 논문집 전기기기 및 에너지변환시스템부문
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    • pp.296-298
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    • 2005
  • Urban transit is system that offer target Performance and function because various lower part system such as vehicles, signaling, power supply, rail track is consisted as complex. It is important first of all that describe correctly system requirement until configuration of system, design, manufacture, installation and test verification so that the complicated urban transit system is to act safety and reliable and to display target Performance and function properly. The system requirement assist the system developer to comprehensive the performance and function of system in basic design. Therefore, In this paper wishes to study way to analyze system of system requirement and apply to Urban transit.

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