• 대한전자공학회논문지SD
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• 제43권11호
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• pp.69-76
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• 2006

본 논문에서는 생명체의 구조를 모방하여, 다중고장에 대한 효율적인 자가치유시스템 구조를 제안한다. 기존의 자가치유시스템은 인공 셀의 데이터의 패스가 좌우상하로만 가능하여 열 단위 치유만이 가능했다. 또한, 인공 셀의 게놈블록의 설계에 있어서, gene정보 저장방식을 이용함으로써 하드웨어 오버헤드가 큰 문제점이 있다. 본 논문에서는 인공 셀의 데이터의 패스를 대각선으로도 가능하게 설계하여, 열 단위가 아닌 셀 단위로 고장 셀의 용이한 대체가 가능하고 다중고장에 대해서도 효율적으로 자가치유가 가능하다. 또한, 게놈블록은 로직기반 생성방식을 이용하여 설계함으로써 저면적 설계가 가능하다. 2진 up/down 카운터를 예제로 하여 설계한 결과 하드웨어 오버 헤드를 약 40.3% 개선했다.

• 한국경영과학회지
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• 제25권4호
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• pp.27-44
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• 2000

In this study we consider a spares provisioning problem for repairable items in which a parts inventory system is incorporated. If a machine fails, a replacement part must be obtained at the parts inventory system before the failed machine enters the repair center. The inventory policy adopted at the parts inventory system is the (S, Q) policy. Operating times of the machine before failure, ordering lead times and repair times are assumed to follow a two-stage Coxian distribution. For this system, we develop an approximation method to obtain the performance measures such as steady state probabilities of the number of machines at each station and the probability that a part will wait at the parts inventory system. For the analysis of the proposed system, we model the system as a closed queueing network and analyze it using a product-form approximation method. A recursive technique as well as an iterative procedure is used to analyze the sub-network. Numerical tests show that the approximation method provides fairly good estimation of the performance measures of interest.

• 품질경영학회지
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• 제28권3호
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• pp.11-17
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• 2000

This paper presents a model for determining the optimal number of general repairs and supplementary input cost limit rate in addition to minimal repair cost rate to implement preventive maintenance. The basic concept parallels the periodic replacement model with minimal repair at failure introduced by Barlow and Hunter(1960) and Park(1979), only difference being the replacement signalled by the number of previous general repairs performed on the system. A general repair brings the state of the system to a certain better state than before repaired. Numerical examples are provided.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 1999년도 봄 학술발표회 논문집(I)
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• pp.762-767
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• 1999

This paper presents an experimental study on flexural behavior of damaged RC beams repaired with epoxy mortar system. The main test variables are repair length and depth. A series of 7 specimens was tested to show the corresponding effect of each variables on maximum load capacity, load-deflection relationship, and failure mode. The results of this study shows that flexural behavior of repaired RC beams changes as the repair length and depth is getting longer and deeper, so that the tension strength of repairing materials should be considered in the courses of repair design.

• 산업경영시스템학회지
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• 제20권43호
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• pp.241-247
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• 1997

This paper is concerned with cost analysis model in free-replacement policy. The free-replacement policy with minimal repair is considered as follows; in a manufacturer's view point operating unit is periodically replaced, if a failure occurs between minimal repair and periodic maintenance time, unit is remained in a failure condition. Also unit undergoes minimal repair at failures in minimal-repair interval. Then total expected cost is calculated according to the parameter of failure distribution in a view of consumer's. The expected costs are included repair cost and usage cost: operating, fixed, minimal repair and loss cost. Numerical example is shown in which failure time of item has weibull distribution.

• 한국콘텐츠학회논문지
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• 제16권6호
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• pp.481-492
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• 2016

본 연구는 국내 장애인보조기구 수리서비스에 대한 현황 및 만족도를 파악하여 수리서비스에 대한 문제점을 알아보고 이를 바탕으로 하여, 효과적인 발전방안을 알아보고자 하는데 그 목적이 있다. 설문조사는 2015년 7월부터 2015년 10월까지 전국에 있는 장애인 750명을 대상으로 시행하였고, 최종 회수된 280부를 분석하였다. 수리의뢰가 많았던 품목은 대부분 이동보조기구였으며 수리 의뢰는 대부분 구입업체와 장애인 보조기구 전문 수리기관에서 시행되었다. 만족도 조사에서 일부 불만족의 사유로는 수리기간이 길고 수리 접수 및 절차의 복잡성으로 나타났다. 장애인보조기구 수리서비스 활성화를 위한 중앙정부의 역할로는 수리지원사업에 대한 홍보 확대, 수리지원 대상품목 및 지원금액 기준마련, 장애인보조기구 수리를 위한 법적 체계 마련이 매우 필요하다는 의견이 많았다. 보다 효과적이고 체계적인 장애인보조기구 수리서비스를 제공하기 위해서는 수리서비스 절차의 체계 확립, 시장가격을 반영한 부품별 수리단가 제시 등이 마련되어야 할 것이다.

• 디지털콘텐츠학회 논문지
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• 제9권4호
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• pp.717-723
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• 2008

국내 많은 PC 제조업체 및 전문수리센터의 엔지니어들이 효율적인 진단 데이터베이스 시스템이나 CAD 툴의 부재로 신속하고 정확한 PC 장애 진단 및 보수에 많은 어려움을 겪고 있다. 본 논문에서는 이러한 문제를 해결하기 위하여, PC 유지보수를 위한 진단 데이터베이스 시스템을 제안한다. 제안하는 진단 데이터베이스 시스템을 사용하면 소프웨어 및 하드웨어 장애를 갖는 PC를 정확하고 신속히 진단할 수 있어 고객의 만족도를 높일 수 있다. 나아가 일선에서 일하는 PC 정비사들로 하여금 유지 보수 기술을 축적하고 소비자들의 PC 성능에 대한 신뢰도를 향상시킬 수 있게 된다.

• 한국경영과학회지
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• 제23권4호
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• pp.111-130
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• 1998

We propose an imperfect repair model which depends on external effects quantified by covariates. The model is based on the Brown-Proschan imperfect repair model wherefrom the probability of perfect repair is represented by a function of covariates. We are motivated by deficiency of the BP model whose stationarity prevents us from predicting dynamically the time to next failure according to external condition. Five types of function for the probability of perfect repair are proposed. This article also presents a procedure for estimating the parameter of the function for the probability of perfect repair, as well as the inherent lifetime distribution of the system, based on consecutive inter-failure times and the covariates. The estimation procedure is based on the expectation-maximization principle which is suitable to incomplete data problems. focusing on the maximization step, we derive some theorems which guarantee the existence of the solution. A Monte Carlo study is also performed to illustrate the prediction power of the model as well as to show reasonable properties of the estimates. The model reduces significantly the mean square error of the in-sample prediction. so it can be utilized in real fields for evaluating and maintaining repairable systems.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2007년도 춘계학술논문 발표대회
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• pp.129-132
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• 2007

In this study, for the establishment of the performance evaluation methods of repair material and method for reinforced concrete structure and the quality control standards of durability recovery method, the quantitative exposure data by exposure experiment under the coastal and normal atmosphere environment is accumulated and analyzed. Investigating and evaluating the result of exposure experiment during 54 months of exposure age under the coastal and normal atmosphere environment, Micro crack, swelling and spatting of surface coating material, crack of repair boundary parts and the great potential difference between repair part and non-repair part were somewhat generated. And the result shown that exposure specimen of coastal environment had lower electrode potential than exposure specimen of normal atmosphere environment.

• 한국도로학회논문집
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• 제15권6호
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• pp.49-60
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• 2013

PURPOSES : The evaluation of the pavement condition of the asphalt concrete pavement of No. 2 runway of Inchon International Airport through PMS, a supporting system for making a decision of pavement, maintenance and repair, was made, and the proper time for repair according to the PCI reduction rate was suggested. METHODS : By comparing and analyzing the evaluation results of pavements built in 2009, 2010, 2011, PCI change in each facility (No. 2 runway, C parallel taxiway, connection taxiway) was calculated. By applying the calculated change to PCI deduction rate model, the pavement condition of the target sections was estimated, and then the necessary section and time for repair were chosen. RESULTS : After careful consideration of the time for pavement and maintenance, based on the result of PCI prediction, it was estimated that the southern takeoff and landing section of No. 2 runway was required to be repaired in 2012; connection taxiway in 2013; and C parallel taxiway in 2014; however, the section which is the main moving route of connection taxiway and C parallel taxiway was needed to be repaired in 2012. CONCLUSIONS : For maintenance and repair of airport pavements, the optimal alternative should be chosen by considering economics and operability, via examining the time for repair and the aspect of management all together on the basis of this study.