• 한국자동차공학회논문집
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• 제13권2호
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• pp.157-161
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• 2005

In the FY 2003, the number of registered vehicles in Korea reached 14 million, which is 7.7% increase from the previous year. The increase of number of vehicles has caused a lot of social problem with enormous costs. The social costs related to the vehicles includes environmental costs resulting from pollution and scraping of vehicles, those resulting from life-saving and repairing from car accidents and so on. There have been m any efforts to reduce the social costs in m any areas. As a part of the efforts, there are recent grow ing interests on the damageability & repairability in related industries. In this study, we investigated the cases of two different types of bum per stay. Futhermore, we analyzed their effects on damageability & repairability and reduction of repair cost. So we found that if the manufacturers design new cars with good damageability & repairability, then the total repair cost in crash will be reduced.

• 한국콘텐츠학회논문지
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• 제13권4호
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• pp.399-406
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• 2013

최근 기업의 비즈니스 프로세스를 혁신하고 효율화하기 위한 다양한 연구가 활발히 진행되고 있는 가운데, 의미 있는 비즈니스 프로세스 모델을 생성하고 분석하는 프로세스 마이닝 연구 분야가 주목받고 있다. ERP (Enterprise Resource Planning) 시스템이나 BPM (Business Process Management) 시스템에서 발생되는 업무 처리 내역이나 이벤트 로그를 분석하여 의미 있는 정보나 규칙을 발견해 낼 수 있는 프로세스 마이닝 기법은 다양한 분야에서 적용되고 있다. 본 연구에서는 프로세스 마이닝 도구인 ProM 시스템을 실제 고장 수리 사례에 적용하여 고장 수리 프로세스를 분석하고 제품의 주요 고장 패턴을 발견하는 방법을 제시한다. 고장 수리 프로세스 분석 결과 단순 통계 분석 결과에서 발견할 수 없었던 연결된 흐름의 빈도 분석이 가능하였으며, 연결된 흐름들 중에서 문제가 되는 프로세스에 대한 업무 향상 방안을 제시할 수 있었다.

• Journal of Communications and Networks
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• 제17권6호
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• pp.582-591
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• 2015

A massive distributed storage system is the foundation for big data operations. Access latency performance is a key metric in distributed storage systems since it greatly impacts user experience while existing codes mainly focus on improving performance such as storage overhead and repair cost. By generating parity nodes from parity nodes, in this paper we design new XOR-based erasure codes hierarchical tree structure code (HTSC) and high failure tolerant HTSC (FH HTSC) to reduce access latency in distributed storage systems. By comparing with other popular and representative codes, we show that, under the same repair cost, HTSC and FH HTSC codes can reduce access latency while maintaining favorable performance in other metrics. In particular, under the same repair cost, FH HTSC can achieve lower access latency, higher or equal failure tolerance and lower computation cost compared with the representative codes while enjoying similar storage overhead. Accordingly, FH HTSC is a superior choice for applications requiring low access latency and outstanding failure tolerance capability at the same time.

• Computers and Concrete
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• 제7권3호
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• pp.249-269
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• 2010

Managing and reusing knowledge in engineering and construction sectors can lead to greater competitive advantage, improved designs, and more effective management of constructed facilities. The use of Information Technology (IT) in design and construction can exploit strategic opportunities for new ways of integration, sharing and facilitating information and knowledge in any field of engineering. The integrating of separate areas of IT can be used to bring a group of experts and specialists in any field of engineering closer together by allowing them to communicate and exchange information and expertise that facilitate knowledge capture, sharing, and reuse. A lack of an advisory management system and a need to marshal all available data in a common format has indicated the need for an integrated engineering computing environment to investigate concrete repair problems. The research described in this paper is based upon an evaluation management system (EMS) which comprising a database management system (REPCON) alongside visualisation technologies and evaluation system (ECON) is developed to produce an innovative platform which will facilitate and encourage the development of knowledge in educational, evolution and evaluation modes of concrete repair. This allows us to create assessment procedures that will allow the current condition of the concrete structure and its components to be expressed numerically using a confidence level (CL) so as to take the best course of action in the repair and maintenance management. The explained rating system, which is related to structural integrity and serviceability of the structure, allows the confidence level to be determined by visual inspection and the descriptive information and pictures taken from an available REPair of CONcrete (REPCON) database.

• 한국정보통신학회논문지
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• 제14권8호
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• pp.1877-1886
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• 2010

본 논문에서는 전기적인 퓨즈 프로그래밍을 이용한 1T-SRAM 리페어용 리던던시 제어 회로를 설계하였다. 공급전원이 낮아지더라도 외부 프로그램 전원을 사용하여 높은 프로그램 파워를 eFuse (electrical fuse)에 공급하면서 셀의 읽기 전류를 줄일 수 있는 듀얼 포트 eFuse 셀을 제안하였다. 그리고 제안된 듀얼 포트 eFuse 셀은 파워-온 읽기 기능으로 eFuse의 프로그램 정보가 D-래치에 자동적으로 저장되도록 설계하였다. 또한 메모리 리페어 주소와 메모리 액세스 주소를 비교하는 주소 비교 회로는 dynamic pseudo NMOS 로직으로 구현하여 기존의 CMOS 로직을 이용한 경우 보다 레이아웃 면적을 19% 정도 줄였다. 전기적인 퓨즈 프로그래밍을 이용한 1T-SRAM 리페어용 리던던시 제어 회로는 동부하이텍 $0.11{\mu}m$ Mixed Signal 공정을 이용하여 설계되었으며, 레이아웃 면적은 $249.02{\times}225.04{\mu}m^{2}$이다.

• 한국산학기술학회논문지
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• 제20권9호
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• pp.247-254
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• 2019

최근 군수장비를 설계함에 있어 개발 초기부터 장비의 신뢰도, 정비도, 정비시간 등 운용 유지에 대한 많은 관심을 보이고 있다. 그렇기 때문에 사용자 및 개발자 모두 정비시간을 고려한 설계에 대한 중요성을 강조한다. 본 논문에서는 설계 초기에 기존 방식인 MIL-HDBK-470A에서 제공하는 표준 정비 시간이 아닌, 장비의 접근 복잡도등 현실적인 정비시간을 예측하는 것에 대한 구체적인 방법론을 연구하였으며, 정비 복잡도라는 척도를 사용하여 시간변환계수를 적용하였다. 또한, 해당 결과물을 이용하여 기 개발된 장비의 실측 정비시간과 시간변환계수가 적용된 지연시간을 반영한 현실적인 정비시간을 비교/검증하여, 해당 데이터의 신뢰성을 검증해 보았다. 향후 장비 설계 시 정비도 목표값 설정 및 정비도 산출을 위한 연구에서, 초기 실 장비에 대한 정비 시간을 측정하지 못하는 장비의 정비시간을 보다 현실적인 정비시간으로 반영하고, 연구 및 설계반영 활동 등을 통하여 정비시간을 단축하여, 운용 유지 비용 등을 줄일 수 있는 활동 등을 수행할 수 있을 것으로 기대한다.

• 조명전기설비학회논문지
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• 제27권1호
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• pp.61-67
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• 2013

The turnout point system is installed to separate the main rail track from other tracks in rail load stations. It is also important to set up the switch point system to change the direction of the turnout point, to lead and change the direction of tracks. The switch point system can be negatively affected by heavy snow during winter seasons which can cause critical safety problems. Furthermore, the maintenance and repair of the conventional system is prohibitively expensive due to its complexity and high probability of failure. In this paper, an efficient switch point system is proposed which simplifies the equipment structure and lowers the cost for maintenance and repair, while improving safety and performance of the rail road system.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2002년도 춘계학술대회 논문집
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• pp.104-107
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• 2002

Direct Metal Manufacturing (DMM) is a new additive process that aims to take die making and metalworking in an entirely new direction. It is the blending of five common technologies : lasers, computer-aided design (CAD), computer-aided manufacturing (CAM), sensors and powder metallurgy. The resulting process creates parts by focusing an industrial laser beam onto a tool-steel work piece or platform to create a molten pool of metal. A small stream of powdered tool-steel metal is then injected into the melt pool to increase the size of the molten pool. By moving the laser beam back and forth, under CNC control, and tracing out a pattern determined by a computerized CAD design, the solid metal part is built line-by-line, one layer at a time. DMM produces improved material properties in less time and at a lower cast than is possible with traditional fabrication.

• Journal of Ship and Ocean Technology
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• 제1권1호
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• pp.26-34
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• 1997

Under water wet welding is an economically alternative for the repair of offshore structures. In this paper investigations on the fatigue strength of a wet welded pipe structural member have been reported. For the connection a special sleeve patch design has been developed. The joint was fatigue tested. The evaluation of the test was carried out by means of the hot-spot approach with regard to several extrapolation rules of the hot-spot stress. Obtained results have been compared to actual classfication rules and recommendations.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 1999년도 봄 학술발표회 논문집(I)
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• pp.525-528
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• 1999

Structural walls have been favored for the design of reinforced concrete buildings in seismic zone areas because they provide an efficient bracing system and offer great potential for lateral load resistance and drift control. Loads on structures due to earthquakes are not unlikely to reach, if not exceed, the design load levels. Hence, structural damage to walls is inevitable, and it is necessary to repair this damaged walls. Yet, information on repair method and data related to the strength and deformation characteristics of repaired walls is limited. In this study, specimens which have their aspect ratios of about 1 to 3 will be repaired. For the repairing the damaged walls, new concrete and new reinforcing bar are replaced with cracked concrete and the buckled reinforcing bar, respectively. The objective of this study is to evaluate the performance of the repaired structural walls in the capacity of strength, stiffness, and maximum deformation comparing with the undamaged walls.