• Journal of the Korea Academia-Industrial cooperation Society
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• v.18 no.4
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• pp.592-598
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• 2017

The purpose of this study is to suggest a new inspection period of ${\triangle}{\triangle}$ guided missiles by analyzing their reliability using field data. The ${\triangle}{\triangle}$ guided missile has an inspection period of five years which was determined using prediction data during its development process. However, from the analysis of its field data, it was shown that the inspection period could be extended to more than 18 years. Based on this result, a policy is proposed to reevaluate the inspection period by means of practical reliability tests.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.32 no.6D
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• pp.663-671
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• 2012

The demand of CWR is rapidly increasing because of the adaptation of concrete track, the need for rapid and comfortable ride, and the reduction of maintenance cost. Because of short applying period of the concrete track, there is not a case of CWR fracture in Korea caused by repeated load of the train, which makes it difficult to calculate replacement period of rail based on rail fatigue life using an actual field data. This study thus inspected the bending stress at rail bottom through analyzing the vehicle/track interaction, performed multiple regression analysis on the data, deducted the bending stress prediction equations by the speed and the surface irregularity. Finally, the fatigue life of CWR on the concrete track was predicted based on the prediction equations for bending stress at rail bottom.

• IE interfaces
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• v.23 no.3
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• pp.221-228
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• 2010

With the development of science and technology, modern submarines are equipped with high technology devices and multi-functioned precise armaments, consequently, acquisition cost as well as maintenance cost of the submarines are getting higher and higher. However, tight defense budget forces navy to significantly reduce military operating and maintenance costs. In this study, the maintenance and operating costs of submarine Jangbogo-II are estimated through M&S (Modeling and simulation) methodologies in order to reasonably and consistently work out the requirement verification system of Jangbogo-II. The maintenance and operating costs of Jangbogo-II along the next 25 years are estimated as 312.65 billion won via engineering analysis methods while 312.69 billion won from PRICE Model, which shows only 0.04 billion won differences as a whole. This study is expected to be able to provide meaningful decision making data for not only short and/or mid term operating planning but military budgeting.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.67 no.2
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• pp.331-336
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• 2018

In this paper, the life cycle cost of the auxiliary power unit in the conventional 8200 series electric locomotive is evaluated and an effective life cycle cost reduction method is sought. For this, a life cycle cost evaluation model was proposed using IEC 60300-3-3 standard. As a result of analysis, material cost which accounted for a large percentage of preventive maintenance cost, accounted for 64% of total cost, and breakdown maintenance cost was as high as 27%. Except for the cost of preventive maintenance, the breakdown maintenance cost ratio was the highest. In order to reduce the LCC of the auxiliary power unit(APU) of the 8200 series in the future, it is necessary to reduce the material cost in case of development and to secure the high reliability according to the parts manufacturing so as to minimize the maintenance cost.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.67 no.11
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• pp.1523-1529
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• 2018

Electric vehicles that are currently in operation are being produced domestically. Therefore, there is no great difficulty in receiving or repairing the failed parts or in the overall repair. On the other hand, most of the electric locomotives are manufactured by introducing the parts and technology of foreign vehicle manufacturers. In this paper, conducted a study about life cycle cost analysis of developed auxiliary power unit in 8200 series electric locomotive and suggested cost down method. This confirms the economic benefits of the developed products of the auxiliary power supply compared to the existing products. In addition, a sensitivity analysis of MTBF was conducted to suggest a life cycle cost down method.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.13 no.4
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• pp.279-288
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• 2001

This paper is to derive energy retrofit strategies through energy audit and analysis for a selected small-to-medium office building located in Seoul, Korea,. To activate ESCO business in Korea, our final goal is to develope a simple and adequate energy retrofit procedure through computer simulation. Calibration process was fairly successful eve without the aid of tough field measurement. In terms of annual energy consumption, the percent difference between the predicted and the monitored values were within a reasonable tolerance of $\pm10$%. Based on the calibrated baseline model and the systematic investigation of target building, retrofit measures were suggested with two categories such as architectural side and equipment side. Both selected parametric and interactive retrofit measure simulations resulted in various energy saving quantities and cost, thus the priority among the measures were made. If we were to select the more realistic and reasonable retrofit measure in future, economic estimate were should be practiced with the life cycle cost analysis.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.36 no.2
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• pp.157-164
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• 2012

When designing a multifunctional system consisting of many components performing many functions or missions, it is important to determine the reliability, availability, and maintainability (RAM) of the system and components, and we consider system availability to be the optimization criterion. For given intervals of mean time between failure (MTBF) and mean time to repair (MTTR) of the components, we want to determine the values of MTBF and MTTR for all components that satisfy the target availability. A heuristic method is proposed for finding near-optimal solutions through simulation. We also study numerical examples to check effects of model parameters on the optimal solutions.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.60 no.11
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• pp.2176-2181
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• 2011

This paper estimates the life cycle cost(LCC) of a propulsion control system using the maintenance information in the high speed train(KTX-1). Life cycle costing is one of the most effective approaches for the cost analysis of long-life systems such as the KTX-1. Until now, most life cycle cost of the system has been studied as a whole system viewpoint. But in case of railway industry, LCC studies are needed on the subsystem like a propulsion control system because subsystems are developed continuously localization. This paper proposes the life cycle cost model which fitted to estimate life cycle cost (LCC) using maintenance information manual. As a result, LCC on propulsion control system increased moderately expect for periodical time when major parts are replaced at the same time. Results will be reflected in the development of domestic products.

• Journal of the Korea Institute of Military Science and Technology
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• v.2 no.2
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• pp.166-172
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• 1999

Weapon system is defined as a combination of primary system and logistics support system which are evaluated by capability and operational availability respectively. Weapon system developer thought that primary system was weapon system and also only primary system was important. Recent comparison of total life cycle cost showed that logistics support system was proved to be more important than primary system. However, until now no systematic approach to logistics support system development have applied in the area of developing support system and much money was exhausted by wrong logistics support system. We need to construct a universal metric for effectiveness of logistics support system and to cut out whatever activities or support elements which do not contribute to the metrics. This study describes a new approach under the name function approach to logistics support system development and also classifies five factors of failure frequency, stock out of frequency, administrative delay time, active repair time and logistic delay time that have influence on operational availability of logistics support system.

• The Journal of the Korea Contents Association
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• v.15 no.7
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• pp.128-137
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• 2015

Going through rapid changes, the field of information technology (IT) has launched many innovative products. Some of those products have spread, forming a stable market, whereas others have disappeared. The purpose of the study is to purpose a theoretical model to show changes in the importance of competition factors over the three stages. Our study applied the innovation adoption stage model of the Innovation Diffusion Theory (IDT) to the industry life cycle of the Industry Life Cycle (ILC) Theory resulting in three stage of introduction, growth, and maturity, and defined a model of market characteristics according to time. By using the model, we analyzed the case of notebook computers and tablet and checked the fitness of the model. Results show that five competition factors worked differently according to time. In the introduction stage, relative functionality and relative playfulness are important competition factors. In the growth stage, compatibility is added to those two factors. In the last maturity stage, compatibility, complexity, and cost level are important competition factors.