• 한국산업융합학회 논문집
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• 제24권6_2호
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• pp.861-872
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• 2021

An efficient cost management is important for the domestic social overhead capital(SOC) based on a long lifecycle after 30 years since completion. Maintenance in South Korea have had the restrictions of consistency and suitability of decision-making by the establishment of a budget plan based on the company estimate and repair and reinforcement methods determined by the inspection and diagnosis engineers' subjective determination for each facility. To resolve this issue, the Korea Institute of Civil Engineering and Building Technology is currently in development of a methodology to propose an optimum maintenance method according to the damage of components by artificial intelligence. This study has deduced the primary factors by analyzing information generated during bridge maintenance and management as a prior step for the development of technologies, and conducted a preliminary analysis to select the optimum artificial intelligence technology.

• 한국농공학회지
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• 제44권3호
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• pp.101-110
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• 2002

Most of the agricultural structures are in shortage of feasible facility management because these structures are small in size and spacially distributed in rural area. Inspection tools based on visual inspections are generally used for agricultural structures in most of the countries, including Korea. It is necessary to survey data of the irrigation structures to maintain records, and to develop the interface program by constructing database of inspection data. This study was conducted to develop a system for safe appraisal and repair works on agricultural irrigation structures. Repair and rehabilitation method can be chosen from an optimum viewpoint if the information between the method and life-cycle management cost of agricultural structures is constructed in the database. In this study, the system assisting onsite field investigation and determining the typical rehabilitation method of typical agricultural structural problems such as fractures and cracks of members was developed.

• 한국국방경영분석학회지
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• 제24권1호
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• pp.98-109
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• 1998

This study develops a maintenance strategy for a reparable 2-unit standby system. The maintenance strategy implies the waiting time to call the repair facility when the unit-1 fails. Almeida and Souza set up the multi-attribute utility function consisting of system availability and repair cost for several maintenance strategies and decide the optimal maintenance strategy that maximize the expected value of the utility function. We decide the optimal maintenance strategy satisfying the following two criteria about the utility function : maximum variance using Almeida and Souza's utility function. It both criteria are not satisfied at the same time for every strategies, the strategy maximizing the lower confidence limit for expected utility function is regarded as an optimal one.

• 대한산업공학회지
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• 제25권4호
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• pp.466-475
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• 1999

A backward Dynamic Programming(DP) model for the optimal facility replacement decision problem during a finite planning horizon is presented. Multiple alternative challengers to a current defender are considered. All facilities are assumed to have finite service lives. The objective of the DP model is to maximize the profit over a finite planning horizon. As for the cost elements, purchasing cost, maintenance costs and repair costs as well as salvage value are considered. The time to failure is assumed to follow a weibull distribution and the maximum likelihood estimation of Weibull parameters is used to evaluate the expected cost of repair. To evaluate the revenue, the rate of operation during a specified period is employed. The cash flow component of each challenger can vary independently according to the time of occurrence and the item can be extended easily. The effects of inflation and the time value of money are considered. The algorithm is illustrated with a numerical example. A MATLAB implementation of the model is used to identify the optimal sequence and timing of the replacement.

• Journal of Microbiology and Biotechnology
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• 제32권2호
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• pp.238-247
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• 2022

Since the skin covers most surfaces of the body, it is susceptible to damage, which can be fatal depending on the degree of injury to the skin because it defends against external attack and protects internal structures. Various types of artificial skin are being studied for transplantation to repair damaged skin, and recently, the production of replaceable skin using three-dimensional (3D) bioprinting technology has also been investigated. In this study, skin tissue was produced using a 3D bioprinter with human skin cell lines and cells extracted from mouse skin, and the printing conditions were optimized. Gelatin was used as a bioink, and fibrinogen and alginate were used for tissue hardening after printing. Printed skin tissue maintained a survival rate of 90% or more when cultured for 14 days. Culture conditions were established using 8 mM calcium chloride treatment and the skin tissue was exposed to air to optimize epidermal cell differentiation. The skin tissue was cultured for 14 days after differentiation induction by this optimized culture method, and immunofluorescent staining was performed using epidermal cell differentiation markers to investigate whether the epidermal cells had differentiated. After differentiation, loricrin, which is normally found in terminally differentiated epidermal cells, was observed in the cells at the tip of the epidermal layer, and cytokeratin 14 was expressed in the lower cells of the epidermis layer. Collectively, this study may provide optimized conditions for bioprinting and keratinization for three-dimensional skin production.

• 한국재난정보학회 논문집
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• 제18권2호
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• pp.290-305
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• 2022

연구목적: 현재 항만시설 정보화 기술은 계획과 설계단계에 편중되어 있어 생애주기 차원의 정보를 기반으로 한 항만시설 유지관리 체계에 관한 연구와 기술 개발의 필요성이 강조되고 있다. 연구방법: 항만시설의 유지관리 이력 데이터 및 시설 운영정보를 기반으로 항만시설의 생애 주기적 관점에서 노후화 패턴 분석과 성능저하 예측 모델, 리스크 분석을 통해 항만시설에 대한 유지관리 의사결정이 가능하도록 시스템 구성하고 정보를 표출하는 방법을 제안하였다. 연구결과: SOC성능평가와 본 연구에서 개발한 종합성능평가를 동시에 표출하는 기능을 개발하여 중장기적인 보수보강 및 시설 확충 등의 적용과 비교판단을 할 수 있도록 개발하였다. 결론:본 연구에서 개발한 항만 통합성능 시스템은 항만시설물에 대한 이력 정보 및 운영정보를 통해 적정한 보수, 보강 등 조치를 선제적으로 추진하게 함으로서 항만시설관리의 리스크 최소화를 유도하고 지원할 것으로 기대된다.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2008년도 춘계학술대회 논문집
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• pp.243-248
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• 2008

Seoul subway is an safety, quick, and clean public transportation to secure citizens safety. One of the most important elements of train is optimizing railroad function and need to conform railroad inspection for function maintenance. Railroad is the most biggest part of the railroad facility and it is a structure which requires sustainable maintenance. The purpose of study is to improve domestic metropolitan railroad facility inspection method and period. For this, we refer documents about present roving method, roving members and period of railroad roving. In addition, analyzed problems of railroad roving investigation method and period by examining the type and standards of railroad investigation and interviewing experts. By this, we analyzed improving plan and expectations of railroad maintenance and repair operation.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2015년도 추계 학술논문 발표대회
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• pp.81-82
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• 2015

BIM has been a reliable construction project management tool to handle various kinds of construction information generated in the facility life cycle. To take these advantages, researchers have been promoted numerous studies in a residential, a commercial, and an educational facilities with a large number of on-going projects. However, despite running as the role of essential energy supplier, power plant related BIM research is relatively insufficient than others. In particular, due to the extending of the facility service period and the requirement of the complicated construction project management for 'overhaul' and 'repowering' in the power plant maintenance phase, the needs for using BIM have been increased gradually. For using BIM based maintenance, it is needed to consider an information collecting methods and necessary to develop an appropriate breakdown structure to share information. Therefore, 'EBS' is produced by reviewing the previous research related to BIM and analyzing the repair activities in the maintenance phase. Proposed 'EBS' must be useful not only a judgment between capital expenditure versus revenue expenditure but also appropriate maintenance strategies development for property management.

• 한국안전학회지
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• 제26권5호
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• pp.7-12
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• 2011

The crash cushion has drawn a great attention because of its versatility, efficiency and simplicity in reducing the mortality and damages from traffic accidents. However, the existing cushion systems are high priced or have limited functions. The purpose of the study was to devise an improved crash cushion which can offer higher safety compared to the available ones at present. In addition, the conformity of the cushion with the facility standards was assessed through computer simulation for collision with vehicles. The novel cushion system adopts the used tires as shock absorber, which can not only secure cushioning effect but also reduce the production cost. Moreover, it is highly durable and easy to maintain and repair the damaged parts. According to the simulation using BARRIER VII program, the novel cushion system showed PHD of 17.4 g and 10.1 g for a frontal collision and a side collision, respectively. Based on the results, it could be concluded that the novel cushion system met the test standards in the guideline for road safety facility installation and management.

• 한국전통조경학회지
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• 제40권2호
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• pp.59-66
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• 2022

본 연구는 문화재 수리에서 조경분야의 독자성을 확보하고 업역을 정립하기 위한 기준이 되는 조경수리 공종 분류 제시를 목적으로 하였다. 연구 결과는 다음과 같다. 현재 문화재수리 표준시방서는 식재공사 중심으로 조경수리 공종을 명시하였고 품셈은 조경분야를 포함하지 않고 있다. 다만 건설산업의 조경공사 시방서와 품셈을 준용하도록 하여 문화재 수리에서 조경수리 공종이 구체적으로 무엇인지 알기 어려운 실정이다. 따라서 실제 시행된 문화재수리 사업의 내용을 토대로 조경수리 공종을 파악하였다. 과거 1961년부터 1980년에는 수목식재뿐만 아니라 다양한 조경시설도 조경수리로 명시되었고 이 공종들 모두 현재 건설산업의 조경공사 공종으로도 정립되었음을 확인하였다. 또한, 2018년부터 2020년의 3년간 문화재를 대상으로 한 실시설계용역 입찰공고서에 명시된 공종 중 건축물보수 및 단청, 식물보호, 보존처리 분야 공종을 제외하고 종합한 결과 총 20개의 공종이 확인되었다. 20개 공종 모두 건설산업의 조경공사 공종에 해당하였다. 따라서 조경수리 공종은 건설산업 조경공사 공종 분류를 토대로 하되 문화재 공간의 특수성을 고려하여 부지조성 및 대지조형, 식재공사, 시설물공사, 포장공사, 생태조경공사, 식생유지관리의 총 6개로 분류하였다. 국내 산업의 한 분야로 조경이 정착해가던 시기에 이미 다양한 조경시설도 건축분야 수리가 아닌 조경수리로 시행되었으므로 이 시설을 모두 포함하여 조경수리 공종이 문화재 시방서에 구체적으로 명시되어야 할 것이다.