• Journal of the Korea Academia-Industrial cooperation Society
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• v.20 no.10
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• pp.149-158
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• 2019

The scheduling of planned maintenance problem of a system consisting of a number of components was studied. The purpose of maintenance scheduling is to minimize the cost of maintaining long-term operations. On the system side, the cost of a system shutdown can be minimized by grouping and inspecting a number of components. In addition, proper inspection cycles can be selected for each component to identify the failure sufficiently early to minimize the cost of the failure. To reduce the complexity of the calculations, the 'base interval approach' used in previous studies was applied and, in addition, the inspection cost savings from simultaneous inspections of multiple components were considered. To compare the effectiveness of inspection cost savings, this paper presents the results of simulation analysis performed by referring to the cases in the existing studies.

• Proceedings of the KSR Conference
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• 2011.05a
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• pp.1582-1590
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• 2011

An analysis of the railroad industry for R&D investments has been insufficient whereas there are lots of analysis of accumulation of technology, economic performances and ripple effects for macroscopic view and other industry of R&D investments. This study decided intellectual rights, patent, and paper as common indicators of scientific and technological performances for setting up performance targets through surveying and analysis of preceding study and verified a appropriateness of scientific and technological performances for railroad R&D 11 projects which were successfully finished. Preceding study has been set up performance targets by research investments as input, but this study made a performance target by model through a cross-sectional and residual analysis of performances of railroad R&D 11 Projects in applying research investments, capital investments, inner labor cost and inner labor cost per man and research time as inputs, and verified a validity and a empirical analysis through analysis of other project.

• Journal of Korean Institute of Industrial Engineers
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• v.37 no.4
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• pp.390-399
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• 2011

Generally the life-cycle cost of complex systems composed of several sub systems or equipments such as train, aircraft weapon systems is spent much more during operation and maintenance phase than development phase. The maintenance cost for maintaining the availability and extending the life span of systems comprise a large proportion of systems operation cost. The cycle of preventive maintenance affects operation and maintenance cost a lot. In this study we introduce a way minimizing life-cycle cost of systems by calculating more reliable preventive maintenance period than the results of previous study using systems reliability data considered the reliability and failure effect ratio of sub-systems or components. We can solve the preventive maintenance period problem known as NP-Hard as quick as possible by using modified genetic algorithm than using other models introduced in previous study.

• Carbon letters
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• v.16 no.3
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• pp.147-170
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• 2015

In recent decades, there has been an increasing interest in the use of carbon fiber reinforced plastic (CFRP) in aerospace, renewable energy and other industries, due to its low weight and relatively good mechanical properties compared with traditional metals. However, due to the high cost of petroleum-based precursors and their associated processing costs, CF remains a specialty product and as such has been limited to use in high-end aerospace, sporting goods, automotive, and specialist industrial applications. The high cost of CF is a problem in various applications and the use of CFRP has been impeded by the high cost of CF in various applications. This paper presents an overview of research related to the fabrication of low cost CF using polyethylene (PE) control technology, and identifies areas requiring additional research and development. It critically reviews the results of cross-linked PE control technology studies, and the development of promising control technologies, including acid, peroxide, radiation and silane cross-linking methods.

• Journal of the Korean Society of Systems Engineering
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• v.5 no.1
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• pp.7-20
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• 2009

This paper describes a case study on the R&D programs of fighter and attacker aircraft such as F-22A, F/A-18E/F, and T/A-50. F-22A and F/A-18E/F were developed in same age. The performance of each program was, however extremely different. F-22A program results in a lot of cost overrun and schedule delay. On the other hand F/A-18E/F program met the cost, schedule, and performance goals. In the T/A-50 program with a super-sonic advanced trainer, T-50 was also developed successfully on planned cost and time by Korea Air-force and KAI. This paper derives key elements for the success of the military aircraft R&D program through lessons learned from th e case study. Each program is analyzed in terms of its background, planning and management.

• Proceedings of the International Microelectronics And Packaging Society Conference
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• 1999.12a
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• pp.163-193
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• 1999

• Journal of the military operations research society of Korea
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• v.36 no.1
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• pp.29-38
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• 2010

In Korea weapon system acquisition processes, it's required a cost estimation report obtained from a commercial cost model. The PRICE model is generally used as a cost estimation model in Korea. However, the model uses American historical R&D data and it's output cost component is different from our cost component of defense accounting system. Also, we found that estimating results show about 10% of difference when we comparing with actual costs in 44 finished weapon acquisition projects. There are some limitations in calibration to increase an accuracy of the PRICE model because it's difficult obtain good real input data, detailed cost and technical data in low level WBS. So, only 8% of the defense R&D projects are calibrated and validation of calibration results is more difficult. Therefore, we studied the standard calibration process and performed the calibration about the MCPLXS/E parameters of the PRICE model based on actual cost data. In order to obtain a good calculation result, we collected the actual material costs from the defense industry companies. Our results can be used for an reference in similar weapon system R&D and production cost estimation cases.

• Journal of Energy Engineering
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• v.6 no.2
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• pp.145-151
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• 1997

The R&D investment of power industry has significant influences on the social welfare as well as national economy. It is necessary to analyze how efficient the R&D investment has been performed. The objective of this study is to verify the efficiency of the R&D investment in the domestic power industry. A formula was introduced to by calculate the appropriate amount of R&D investment of monopolistic industry under the regulations which are determined by the proportion of R&D elasticity and price elasticity. It has resulted that there would be no economy of scale as the sales of electricity increases at the same rate of the increasing cost. The R&D investment in the present electricity industry has been performed inefficiently by showing the negative impact on price-cost margin of the intensity of R&D investment, which is the extent of R&D investment to reinforce economy of scale.

• 한국정보디스플레이학회:학술대회논문집
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• 2005.07b
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• pp.1466-1469
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• 2005

We report effects of electrical aging on the emission stability of carbon nanotube (CNT) paste for low cost and high low-cost and large area field emission devices or displays. Photosensitive carbon nanotube paste was formulated by using of spin on glass (SOG) as an inorganic binder and investigated emission properties and stability depending on electrical aging condition.

• Proceedings of the Technology Innovation Conference
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• 1998.06a
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• pp.38-56
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• 1998

We are faced with the crisis of the R&D investment because of the effects of the IMF conditions. Most of the laboratories are going to restructure by the cutting off of money, man power and the reduction of R&D thema. Therefore it is necessary to allocate the R&D resources effectively to the R&D projects. The evaluation and the selection of the R&D projects have been recognized as the most important process for the allocation of the R&D resources. The result of the KITA(1997) shows that the commercial success rate of the R&D from new-product brain storming is only 5.8%. This study aims to analyze the actual conditions of the cost benefit analysis(CBA) of R&D projects of selected laboratories and to study measure methods of the R&D benefits. The research method of this study reviews the CBA of R&D firstly, and surveys 200 selected high ranking labs of the R&D expenditures. For the comparison of the results between '87 and '97, this survey used the same questionaries for each year. As the result of the survey only 27 labs(response rate 13.5%) responded. The result of the '97 survey is as follows : The CBA is used by 44% of responding labs. The economic evaluation method for the R&D project selection is used by 48% of labs and this numbers increased by over 10 percents points compared with the result of '87. The CBA is used for about 40% about each of the budget preparing and the budget analysis, and by 30% of labs to analyze sales and expenditures of the overall period of the project. As the measurement of benefits of R&D projects, 30% of labs responded that it is impossible to measure the benefits, and 20% of labs measured the benefits between sales and expenditures of the R&D project.