• Title/Summary/Keyword: 불완전유지보수

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A study on Determining Maintenance Intervals Considering the Maintenance Effect for the PDS in Metro EMU (전동차 승객용도어시스템의 유지보수 효과를 고려한 유지보수 주기 산정에 관한 연구)

  • Lee, Duk-Gyu;Son, Young-Jin;Lee, Hi-Sung
    • Journal of the Korean Society for Railway
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    • v.14 no.3
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    • pp.216-221
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    • 2011
  • An important problem in reliability analysis for repairable systems is to model the maintenance effect. The most of researches have assumed two extreme cases; one is perfect maintenance and the other is minimal maintenance. However, many of maintenances performed by domestic subway operators are imperfect maintenances which have the effect between both of two extreme cases. This article deals with the problem determining the imperfect preventive maintenance intervals based on failure data in units of the PDS(passenger door system) in Metro EMU. This paper deals with a case study on determining imperfect maintenance interval by using the level of maintenance effect through reliability analysis of PDS.

A case study on evaluating the effectiveness of maintenance policies under imperfect maintenance (시뮬레이션을 통한 불완전 유지보수하에서의 유지보수 정책의 효율성 평가에 관한 사례 연구)

  • Lee, Duk-Gyu;Lee, Hi-Sung
    • Proceedings of the KSR Conference
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    • 2008.11b
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    • pp.1539-1544
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    • 2008
  • There is a existing study dealing with the case that the effect of preventive maintenances to restore the door system is imperfect. When the effect of the preventive maintenance is imperfect, we need to consider the maintenance effect for making reliable and economical maintenance policies. The maintenance policies applicable for imperfect maintenance cases are considered and their effectiveness are evaluated through simulation in cases of passenger door system:PDS.

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동적 불완전 수리 모형 및 분석 절차의 개발

  • 백상엽;임태진;홍정식;이창훈;김태운
    • Proceedings of the Korean Nuclear Society Conference
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    • 1996.05b
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    • pp.719-724
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    • 1996
  • 본 연구는 유지, 보수되는 상시 작동 시스템에 대한 신뢰성 분석을 위해 동적 불완전 수리모형 및 분석 절차의 개발을 수행하였다. 또한 수리 상태에 대한 데이타가 완전히 잠재적(masked)이라 하더라도 기본 분포(base-line distribution)가 와이블 분포라는 가정하에 모수적 추정 절차를 개발하였다. 개발된 추정 절차는 기본적으로 EM(Expectation and Maximization : EM) 알고리즘의 틀(framework)을 유지하고 있다. 특히 최소 수리 특성으로 인해 분포가 변화함에 따라 발생하는 추정의 어려움을 해결하기 위해 데이타 변환(transformation)식을 제시하고 이러한 변환 데이타를 사용함으로써 추가적 데이타의 요구없이 잠재적 데이타를 사용하여 추정을 가능하게 하는 모수 추정 알고리즘을 제시하였다.

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A study on determining imperfect preventive maintenance intervals for the doors in Metro EMU (불완전 유지보수 모형을 통한 전동차 도어장치 예방 유지보수 주기 산정에 관한 연구)

  • Lee, Duk-Gyu;Kim, Jong-Woon;Lee, Hi-Sung
    • Proceedings of the KSR Conference
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    • 2008.06a
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    • pp.733-741
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    • 2008
  • An important problem in reliability analysis for repairable systems is to model the maintenance effect. The most of researches have assumed two extreme cases; one is perfect maintenance and the other is minimal maintenance. However, there are many cases in real situations that the maintenance effect are between both of two extreme cases. This article deals with the problem determining the imperfect preventive maintenance intervals for the doors in Metro EMU

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An Input Domain-Based Software Reliability Growth Model In Imperfect Debugging Environment (불완전 디버깅 환경에서 Input Domain에 기초한 소프트웨어 신뢰성 성장 모델)

  • Park, Joong-Yang;Kim, Young-Soon;Hwang, Yang-Sook
    • The KIPS Transactions:PartD
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    • v.9D no.4
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    • pp.659-666
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    • 2002
  • Park, Seo and Kim (12) developed the input domain-based SRGM, which was able to quantitatively assess the reliability of a software system during the testing and operational phases. They assumed perfect debugging during testing and debugging phase. To make this input domain-based SRGM more realistic, this assumption should be relaxed. In this paper we generalize the input domain-based SRGM under imperfect debugging. Then its statistical characteristics are investigated.

The Responsibility of An Infrastructure Manager Toward A Railway Competitive Market (복수운영체제에서 철도시설관리자의 철도시설물 유지보수 조직과 업무 설정)

  • Yun, Gyeong Cheol
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.36 no.1
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    • pp.121-128
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    • 2016
  • The restructuring of Korean railway industry, separation of between train operators and an infrastructure manager, had been conducted in 2004 to increase the productivities of railway operations. However, the maintenance-staffs are still employed by Korail (train operator), not by the infrastructure manager, which led the maintenance of railway infrastructure to be conducted by the train operator. The infrastructure manager is now only taking care of financial transferring issues once the train operator requests expenses spent for facility maintenance. Such incomplete restructure may result in a lack of safety performance on railway operations as the roles and responsibilities are less likely to be assigned under the multiple train operators. Thus, this study proposes the way of structuring maintenance divisions and their roles and responsibilities to assure the safe work execution under the circumstance of multiple train operators on the same rail network.

An object-oriented modeling for process abstraction in highly distributed organizations (분산조직의 프로세스 추상을 위한 객체지향 모델링)

  • 박광호
    • Proceedings of the Korean Operations and Management Science Society Conference
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    • 1995.09a
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    • pp.6-14
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    • 1995
  • 기업경영을 공학적으로 추상하려는 노력은 정보시스템의 개발과정에서 자연 스럽게 시작되었다. 그러나, 정보시스템 구축을 주목적으로 한 공학적 추상 은 실제 업무와 커다란 격차를 가지게 마련이다. 불완전한 업무분석이 정보 시스템 유지보수 비용의 주범이라는 지적은 이러한 주장을 뒷받침하고 있다. 기업경영에 대한 공학적 추상을 도구가 아닌 당위론적인 목적으로 시도하려 는 것은 기업경영의 내부구조를 정립하려는 시도와 동일한 것으로 이해해야 할 것이다. 본 논문은 기업경영에 대한 공학적 추상을 위한 구체적인 방법론 을 제시하고 있다. 객체지향 패러다임이 추상의 방법론으로 적용되었다.

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Development of Dry Process Caisson Method for Maintenance of Submerged Harbor Structure (수중 항만구조물의 유지보수를 위한 건식 케이슨 공법 개발)

  • Lee Joong-Woo;Oh Dong-Hoon;Kwak Seung-Kyu;Kim Sung-Tae
    • Journal of Navigation and Port Research
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    • v.30 no.6 s.112
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    • pp.447-455
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    • 2006
  • Together with the trend of enhancement in domestic industrial development and economic progress due to import and export, the demand for construction of the roads, bridges, especially port facilities, and several coastal protection and ocean structures is increasing rapidly. MOMAF of Korean Government is driving construction cf 9 new ports and renovation cf the existing fishery ports. Among these structures most of bridge base, wharves, dolphins, quays, and jetties are being newly built cf steel or concrete pile. As the base, supporting bulkheads, and piles are underwater after construction, it is difficult to figure out the status of structures and not enough to get maintenance and strengthen the structures. Every year, moreover, these works suck the government budget due to higher incomplete maintenance expense for protection from corrosions cf structures and increased underwater construction period. For the purpose cf cutting down the expense cf government budget, it is necessary to extend the life cycle of the existing structures. Therefore, we developed a new method for maintenance of submerged structures near the waterline by allowing dry work environment with the floating caisson. The method shows easy to move around the working area and handle. It also showed not only a significant reduction of maintenance expenses and time for anti-corrosion work but also better protection This will be a milestone to reduce the maintenance and construction expenses for the shore and water structures.

Development of Dry Process Caisson Method for Maintenance of Submerged Harbor Structure (수중 항만구조물의 유지보수를 위한 건식 케이슨 공법 개발)

  • Lee Joong-Woo;Oh Dong-Hoon;Kwak Seung-Kyu;Kim Sung-Tae
    • Proceedings of the Korean Institute of Navigation and Port Research Conference
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    • 2006.06b
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    • pp.163-170
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    • 2006
  • Together with the trend of enhancement in domestic industrial development and economic progress due to import and export, the demand for construction of the roads, bridges, especially port facilities, and several coastal protection and ocean structures is increasing rapidly. MOMAF of Korean Government is driving construction of 9 new ports and renovation of the existing fishery ports. Among these structures most of bridge base, wharves, dolphins, quays, and jetties are being newly built of steel or concrete pile. As the base, supporting bulkheads, and piles are underwater after construction, it is difficult to figure out the status of structures and not enough to get maintenance and strengthen the structures. Every year, moreover, these works suck the government budget due to higher incomplete maintenance expense for protection from corrosions of structures and increased underwater construction period. For the purpose of cutting down the expense of government budget, it is necessary to extend the life cycle of the existing structures. Therefore, we developed a new method for maintenance of submerged structures near the waterline by allowing dry work environment with the floating caisson. The method shows easy to move around the working area and handle. It also showed not only a significant reduction maintenance expenses and time for anti-corrosion work but also better protection. This will be a milestone to reduce the maintenance and construction expenses for the shore and water structures.

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Sensorles Vector Control to Improve Maintenance Problem in Wound Rotor Type Induction Motor Control System (권선형 유도전동기 제어 시스템의 유지.보수 성능 향상을 위한 센서리스 벡터제어)

  • 이홍희;박창근;정의헌
    • The Transactions of the Korean Institute of Power Electronics
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    • v.6 no.1
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    • pp.57-63
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    • 2001
  • The wound rotor type induction motor(WRIM) control system which is widely used in the industry has many maintenance problem because of external resistors and magnetic contactors. In this paper, the simple sensorless vector control algorithm for WRIM is proposed without any additional devices except detecting rotor currents. Because the external resistors are disconnectd and the rotor slip rings are shorten, the power loss due to external resistors is removed and the maintenance problem is improved remarkably. Also, the vector control performance becomes better because the proposed sensorless vector control algorithm does not use the rotor resistance which is usually used to estimate the slip frequency in case of indirect vector control scheme. The proposed algorithm is verified by the digital simulation and the experiment.

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