• 한국신뢰성학회지:신뢰성응용연구
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• 제18권2호
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• pp.114-121
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• 2018

Purpose: This study proposes a process for evaluating the preventive maintenance policy for a system with degradation characteristics and for calculating the appropriate preventive maintenance cycle using time- and condition-based maintenance. Methods: First, the collected data is divided into the maintenance history lifetime and degradation lifetime, and analysis datasets are extracted through preprocessing. Particle filter algorithm is used to estimate the degradation lifetime from analysis datasets and prior information is obtained using LSE. The suitability and cost of the existing preventive maintenance policy are each evaluated based on the degradation lifetime and by using a minimum repair block replacement model of time-based maintenance. Results: The process is applied to the degradation of the reverse osmosis (RO) membrane in a seawater reverse osmosis (SWRO) plant to evaluate the existing preventive maintenance policy. Conclusion: This method can be used for facilities or systems that undergo degradation, which can be evaluated in terms of cost and time. The method is expected to be used in decision-making for devising the optimal preventive maintenance policy.

• 한국건설관리학회:학술대회논문집
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• 한국건설관리학회 2002년도 학술대회지
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• pp.567-570
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• 2002

우리나라 학교건축은 1990년 중반 이후부터 교육환경의 개선을 위한 시설확충과 노후화된 교육시설물을 유지관리 하기 위한 각종 보수공사의 비용이 증가하고 있다. 교육시설사업을 유지하는 각 주체들간 업무를 수행함에 있어 정보의 분절과 검사방법의 판단기준이 미비하여 한정된 재원의 중복투자 및 낭비를 하고 있다. 따라서 업무절차에 따른 발생정보 및 요구정보를 명확하고 일관되게 제시할 필요성이 제기된다. 학교시설물을 유지 관리 하는 단계에서 이루어지는 업무를 파악하고, 교육청에서 이루어지는 업무를 중심으로 각 기능간 문제점 및 장애요인 분석을 통해 개선프로세스 모델을 제시하고자 한다. 향후 기능간 장애요인 추출을 통한 개선프로세스 모델과 정보 모델구축이 수행되어야 한다.

• Industrial Engineering and Management Systems
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• 제8권4호
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• pp.221-227
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• 2009

There are customer services jointly provided by two facilities so that each customer will complete the course made up of both facilities' sub-services. The two facilities are assumed invested respectively by an infrastructure owner and one subordinate facility owner, whose partnership is built on their capital investments. This paper presents a mathematical model of Stackelberg competition between the two facility owners to derive their optimal Nash equilibrium. In this study, each facility owner's profit is consisted of fixed revenue fractions of sold services, operating costs (including depreciation cost) and maintenance costs of her facility. The maintenance costs of one facility are incurred both by failures and deterioration due to usage. Moreover, for both facilities, failures are rectified immediately by minimal repairs and preventive maintenance is carried out at a fixed time epoch. Additional assumptions are also employed to develop the model such as customer arrivals are manipulated to follow a Poisson process, and each facility's lifetime is independently Weibull-distributed. The Stackelberg game proceeds as follows. At the first stage of decision making process, the infrastructure owner (acting as a leader) decides the allocation of revenue shares based on her self-interest. After observing the allocation of revenue shares, the subordinate facility owner determines her own optimal price of services. This paper investigates actions and reactions of the two partners in the system. Then analytical conditions are proposed to achieve a unique optimal Nash equilibrium. Finally, some suggestions for further research are discussed.

• International Journal of Reliability and Applications
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• 제1권1호
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• pp.1-14
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• 2000

The global marketplace is highly competitive and organisations, who want to survive long-term, have to continuously improve, change and adapt in response to market demands. These improvements should focus on cost cutting, increasing productivity levels and quality and guaranteeing deliveries in order to satisfy customers. Total Productive Maintenance (TPM) is one method, which can be used to achieve these goals. TPM is a change management approach that involves employees from both production and maintenance departments. The purpose is to eliminate major production losses by introducing a program of continuous and systematic improvements to production equipment. TPM should be developed and expanded to embrace the whole organisation and all employees should be involved in the process as members of improvement teams. This paper gives a short description of the development of TPM and the TPM implementation process. Findings are reported from a case study in which one of the authors had the possibility of following and guiding a company through their TPM implementation. The implementation process takes several years and the research has focused on the initial three years. The study demonstrates that driving forces, obstacles and difficulties often are dependent on the organisation, its managers and the individual employees.

• 한국방사성폐기물학회:학술대회논문집
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• 한국방사성폐기물학회 2005년도 Proceedings of The 6th korea-china joint workshop on nuclear waste management
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• pp.60-75
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• 2005

The remote operation of the Advanced Spent Fuel Conditioning Process (ACP) is analyzed by using the 3D graphic simulation tools. The ACP equipment operates in intense radiation fields as well as in a high temperature. Thus, the equipment should be designed in consideration of the remote handling and maintenance. As well as suitable remote handling and maintenance method needs to be provided. To provide such remote operation technology, we developed the graphic simulator which provides the capability of verifying the remote operability of the ACP without fabrication of the process equipment. In other words, by applying virtual reality to the remote maintenance operation, a remote operation task can be simulated in a computer, not in a real environment. In this way the graphic simulator can substantially reduce the design cost of the remote operation process and the equipment. Also it can provide new operation concept that is more reliable, easier to implement, and easier to understand.

• Geomechanics and Engineering
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• 제37권1호
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• pp.9-19
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• 2024

This study presents an energy analysis for large-strain cavity expansion problem based on the general strength criterion and energy theory. This study focuses on the energy dissipation problem during the cavity expansion process, dividing the soil mass around the cavity into an elastic region and a plastic region. Assuming compliance with the small deformation theory in the elastic region and the large deformation theory in the plastic region, combined with the general strength criterion of soil mass and energy theory, the energy dissipation solution for cavity expansion problem is derived. Firstly, from an energy perspective, the process of cavity expansion in soil mass is described as an energy conversion process. The energy dissipation mechanism is introduced into the traditional analysis of cavity expansion, and a general analytical solution for cavity expansion related to energy is derived. Subsequently, based on this general analytical solution of cavity expansion, the influence of different strength criterion, large-strain, expansion radius, cavity shape and characteristics of soil mass on the stress distribution, displacement field and energy evolution around the cavity is studied. Finally, the effectiveness and reliability of theoretical solution is verified by comparing the results of typical pressure-expansion curves with existing literature algorithms. The results indicate that different strength criterion have a relatively small impact on the displacement and strain field around the cavity, but a significant impact on the stress distribution and energy evolution around the cavity.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2010년도 춘계 학술논문 발표대회 1부
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• pp.231-234
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• 2010

Recently, the construction industry has been changed more highly and complicacy. According to this, several informational systems of maintenance are introduced suitable the work and the purpose of each maintenance. However there are some problems in the manage the information of maintenance management by without the standization and systematic management of variable information from building life-cycle. This paper purposed the process of creation or management of information which is used for present maintenance through IFC-based facilities object library development is suggested for work efficiency of maintenance management. In addition, it can minimize the reproduce the same information unnecessarily. Fainally, it makes information compatibility through the building life-cycle highly by define the IFC-based object information and standardize the format of information.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2011년도 춘계 학술논문 발표대회 1부
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• pp.137-140
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• 2011

A systemic building maintenance management is necessary to supply an convenience and safety environment by maintain the origin features for a building's life. However, the exist maintenance management system has some problems such as interoperability of information or standardization of data. In those reasons, a critical information for maintenance a building may be lost and changed. In addition, the data could be crashed or lost on a process of re-input or re-produce. This paper purpose the interoperability in exchanging data between design/construction and operation phases. In addition, this model will enhance the efficiency of building maintenance tasks through information quality improvement and data reproduction prevention.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2011년도 춘계 학술논문 발표대회 2부
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• pp.77-79
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• 2011

As residents and building owners demand maintenance that is required to achieve sustainable building performance, efficient building management methods are required. Even though the demand for maintenance systems is increasing, current maintenance work for high-rise buildings mostly uses conventional ropes and gondolas that pose a high risk of accidents and exhibit poor performance and efficiency. Thus, there is an urgent need to develop an automation robot system that can reduce accidents and improve the maintenance efficiency of the conventional high-rise building façade maintenance system. As a preceding work for the development of an automation robot system, this study classified and analyzed the work processes of actual construction sites and proposed basic techniques for the work mechanisms of the robot system by investigating the motions of cleaning workers.

• 한국건설관리학회:학술대회논문집
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• 한국건설관리학회 2008년도 정기학술발표대회 논문집
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• pp.702-707
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• 2008

교육시설물 BTL 사업은 2005년 긴요하고 시급한 공공시설물을 앞당겨 공급하겠다는 취지하에 시작되었으며, 2007년 3월 준공이 완료되어 운영단계로 접어들면서 유지관리 업무에 대한 관심이 증대되고 있다. 그러나 BTL 사업 시행 초기이고 처음 운영단계에 접어들면서 운영 및 유지관리 업무에 실적 Data가 전무한 실정이다. 이에 본 연구는 교육시설물 BTL 사업의 효율적인 유지관리 업무 수행을 위해 업무 프로세스 도출 및 유지보수 Item을 규명하였다. 이를 통해 유지보수 업무 수행 시 발생되는 정보를 DB화하여 효율성을 극대화 할 수 있는 교육시설물 유지관리시스템 모듈 설계를 목적으로 한다.