• Nuclear industry
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• v.17 no.9 s.175
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• pp.24-33
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• 1997

• Journal of the Korea Academia-Industrial cooperation Society
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• v.15 no.9
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• pp.5502-5512
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• 2014

Until recently, Integrated Logistics Support (ILS) focused mainly on the development and acquisition of supportability factors (maintenance planning, maintenance tools, support equipment, supply support, maintenance training, etc.). In the long term, supportability strategies and policies are needed in terms of LEAN-like cost reduction, efficiency in the field of weapon systems. This study first introduces the concept of Lean, theory of Lean Maintenance and suggests Lean maintenance framework, maintenance strategy for ILS. The case studies were analyzed in terms of the maintenance time, maintenance man-hours, maintenance cost for Lean PM in a radar system. The direction of LEAN on supportability in a weapon system is suggested.

• Korean Journal of Construction Engineering and Management
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• v.7 no.2 s.30
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• pp.89-97
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• 2006

With the increased demand on housing quality and effective urban redevelopment, a new paradigm in reconstruction project is in need. Especially, the Urban and Residential Environment Improvement Law which initiated on July 1, 2003 has become a significant turning point. This code is expected to function as a consistent and systematic measure. This study will examine the code's major concepts and methods to progress reconstruction projects effectively. The application of construction management is examined carefully since the new code requires renewal project consulting firms to function as a professional complement rather than simply perform administration work, as in the past. Also, construction managing methods that can be related to renewal project consulting are examined and speculated. Lastly, methods to improve efficiency in reconstruction projects are introduced through case study and analysis on applicability and expected results.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.18 no.4
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• pp.973-985
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• 2014

This study helps to select the criteria for the location automotive repair shops and suggests the optimum location. The weights representing relative importance of each criterion were calculated by using AHP(Analytic Hierarchy Process). Actually most of the location of automotive repair shops have been selected depending on decision makers' experience though very high initial costs are incurred. Also while studies have been done on the location of the smaller shops whose initial costs are low and service activities are simple, studies and cases on the location of automotive repair shop were not done and found before. This study helps to draw the weights of the criteria for the location of each one of grade 1, 2, 3 repair shop and compare and analyze them. As a result, it is found out that there is some differences between factors significantly considered when selecting the location of each repair shop. This study has significance of suggesting scientific methods to reduce risk in the decision making related to location of repair shop.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.17 no.2
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• pp.1-7
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• 2016

Although the second driving device of KTX, which consists of the wheel and the axle reduction gears unit, is a mechanically integrated structure, its preventive maintenance (PM) requires two separate intervals due to the different technical requirements. In particular, these subsystems perform attaching and detaching work simultaneously according to the maintenance directive. Therefore, to reduce the unnecessary amount of PM and high logistic availability of the train, it is important to optimize PM with regard to reliability-centered maintenance toward a cost-effective solution. In this study, fault tree analysis and reliability of the subsystems, considering the criticality of the components, were performed using the data derived from field data in maintenance. The cost optimization of the PM was derived from a genetic algorithm considering the target reliability and improvement factor. The cost optimization was derived from a maximum of the fitness function of the individual in generation. The optimal TBO of them using the genetic algorithm was 2.85x106 km, which is reduced to approximately 21% compared to the conventional method.

• Journal of Korea Water Resources Association
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• v.36 no.4
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• pp.547-559
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• 2003

In this study, a mathematical model is developed for sewer rehabilitation planning by considering cost and inflow/infiltration. A sewer rehabilitation planning model is required to decide the economic life of the sewer by considering trade-off between cost and inflow/infiltration. And it is required to find the optimal rehabilitation timing, according to the cost effectiveness of each sewer rehabilitation within the budget. To solve the problem, we formulated a multiple objective mixed integer programming(MOMIP) model based on network flow optimization. The network is composed of state nodes and arcs. The state nodes represent the remaining life and the arcs represent the change of the state. The model considers multiple objectives which are cost minimization and minimization of inflow/infiltration. Using the multiple objective optimization, the trade-off between the cost and inflow/infiltration is presented to the planner so that a proper sewer rehabilitation plan can be selected.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.17 no.1
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• pp.274-283
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• 2016

The study of maintenance planning is important in military weapon systems because it can improve their availability and reduce the operational and maintenance cost during the total life cycle. In maintenance planning, it is important to determine the preventive maintenance task and its optimal interval. This paper focuses on the hard time task, which is one of the preventive maintenance tasks. A hard time task removes an item or restorative action before some specified maximum age limit to prevent functional failure. The Monte-Carlo simulation model was proposed to help understand the cost effectiveness of a hard time task. In the simulation, various shape parameters of the Weibull distribution and cost ratio of corrective maintenance to preventive maintenance were assumed. Using a Monte-Carlo simulation, a quantified cost saving effect and optimal preventive maintenance interval were suggested.

• Land and Housing Review
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• v.4 no.3
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• pp.243-258
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• 2013

This study aims to introduce "Street-Housing" Redevelopment Projects adopted by the revision of regulations in 2012 and promote them by surveying residents' needs. The objectives of the street-housing redevelopment projects are to maintain existing street systems and redevelop housing by small units, as an alternative to the large-scale housing redevelopment by the expropriation. Residents, however, do not seem to support the new projects since they are satisfied with their current housing, have difficulty in raising funds, and are uncertain about proceeding with the pre-arranged. Despite these barriers, residents may support the projects if project charges can be lowered by the reduction in each resident's share and the increase in supporting funds. This study proposes new practical methods for realizing the projects: choice of an appropriate site, engaging for resident's participation in projects, reduction in project charges, and removal of barriers to co-operative development. etc.

• Journal of Aerospace System Engineering
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• v.14 no.3
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• pp.32-41
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• 2020

The International Civil Aviation Organization (ICAO) in 2015 proposed a road-map for the global recognition system of the Approved Maintenance Organization (AMO) fto mitigate the redundant work and regulatory burdens of the aviation industry and authorities on the certification and oversight activities of the State of Registry. Since then, the ICAO standards and guidelines have been revised accordingly with the goal of implementing the system in 2024. Korea should actively prepare for this AMO global recognition system to cope with the ICAO road-map appropriately as well as to develop the Maintenance Repair Overhaul (MRO) industry. Thus, this paper focused on the ratings and limitations system, a key element of the AMO, and proposes the improvement of domestic regulatory/administrative rules necessary for the global recognition system, through the review of newly established ICAO standards/guidelines and the comparative analysis of leading aviation countries' and Korean system/requirements.

• Journal of the Korea Society of Computer and Information
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• v.26 no.12
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• pp.255-264
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• 2021

In this paper, we propose operations and maintenance (O&M) planning approach for floating offshore wind farm using the mathematical optimization. To be specific, we present a MILP (Mixed Integer Linear Programming that suggests the composition of vessels, technicians, and maintenance works on a weekly basis. We reflect accessibility to wind turbines based on weather data and loss of power generation using the Jensen wake model to identify downtime cost that vary from time to time. This paper also includes a description of two-stage approach for maintenance planning & detailed scheduling and numeric analysis of the number of vessels and technicians on the O&M cost. Finally, the MILP model could be utilized in order to establish the suitable and effective maintenance planning reflecting domestic situation.