• Journal of the Korea Institute of Military Science and Technology
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• v.13 no.1
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• pp.67-76
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• 2010

RAM(Reliability, Availability, Maintainability) characteristics of weapon system is a part of Required Operational Capability, must be reasonable and achievable. In this study, we studied the criteria, important factors to establish RAM requirement and reviewed the current process. Then we propose the new process and method to establish the reasonable and achievable RAM requirement by BCS(Baseline Comparison System) model.

• Proceedings of the Korean Nuclear Society Conference
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• 1996.05b
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• pp.505-510
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• 1996

A simple model for RAM (Reliability, Availability and Maintainability) analysis and its computer code are developed for application to DUPIC fuel fabrication system. The approach is obtained by linking the allocation model (top-down method) to bottom-up method for RAM analysis. As a result, the availability requirement of subsystem, as well as the buffer storage requirement between processes, are evaluated for the DUPIC facility..

• Proceedings of the Korean Reliability Society Conference
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• 2001.06a
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• pp.503-511
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• 2001

신규 개발되는 기동장비의 RAM-D 요구조건 설정방법에 관하여 기동 무기체계의 대표적 장비인 전차를 대상으로 연구하였으며, 사용자의 장비운용에 대한 요구 가용 능력 및 운용유지 조건을 고려한 RAM-D 요구조건 설정절차 및 분석 모델을 개발하였다.

• Journal of Applied Reliability
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• v.17 no.2
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• pp.150-158
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• 2017

Purpose: The RAM objective is a very important factor that has a great effect on the improvement of the operation ration during the operation maintenance and the reduction of the life cycle cost. It is used as a design criterion during the system development, and its sufficiency should be evaluated during its test evaluation. Method: This study analyzed the cases related to RAM objective setting and suggested the improvement measures. Result: The base data for RAM objective is OMS/MP, which needs to be drawn up under the supervision of the requirement military, and a high-accuracy operating availability should be set through ALDT calculation which reflects the military logistics support environment. In addition, data collection necessary for RAM objective and RAM analysis should be made by supplementing the input data of DELIIS. Conclusion: This study suggests improvement of RAM objective considering for the weapon system.

• Proceedings of the KSR Conference
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• 2009.05b
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• pp.191-198
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• 2009

There are almost no studies on verification of requirements for high speed rolling stocks by means of RAM goals and on setting RAM goals by means of verification on practical reliability, availability and maintainability for high speed rolling stocks though they are covered in specification of an order that RAM goals asked of rolling stocks are shown for gaining high quality of them and availability when they are in operation. This study is for estimating number of high speed train-sets that would be supplementarily placed an order through verification of RAM goals of a project for the introduction of KTX-II 100 cars. It verify that optimized requirements for high speed rolling stocks by relatively comparison with between requirements for train-sets through setting RAM goals and requirements for train-sets through analysis of prospects for management balance with high speed rolling stocks.

• Asian-Australasian Journal of Animal Sciences
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• v.26 no.9
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• pp.1282-1288
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• 2013

A comparative slaughter trial was conducted to estimate the phosphorus (P) requirement for maintenance and growth of crossbred lambs of Dorper with a Chinese indigenous sheep breed, thin-tailed Han sheep. Thirty-five Dorper${\times}$thin-tailed Han crossbred, noncastrated ram lambs ($20.3{\pm}0.22kg$ of shrunk body weight (SBW)) were used. Seven lambs were randomly chosen and slaughtered at 20 kg SBW as the baseline group for measuring initial body composition. Another seven lambs were also randomly chosen and offered a pelleted mixed diet for ad libitum intake and slaughtered at 28 kg SBW. The remaining 21 sheep were randomly divided into 3 groups with 7 sheep each and subject to the same diet of either 70 or 40% of ad libitum intake. The 3 groups were slaughtered when the sheep fed ad libitum reached 35 kg of SBW. Body P contents were determined after slaughter. The results showed that the net P requirement for maintenance was 30.0 mg/kg of empty body weight (EBW) or 23.4 mg/kg body weight (BW), and the P requirement for growth decreased from 5.3 to 5.0 g/kg of EBW gain as the lamb grew from 20 to 35 kg. The net P requirement for growth of Dorper${\times}$thin-tailed Han crossbred ram lambs was lower than that of sheep adopted by the American nutritional system.

• Journal of Applied Reliability
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• v.15 no.4
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• pp.282-288
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• 2015

Purpose : The purpose of this study is to compare the RAM (reliability, availability and maintainability) value in the acquisition phase with operational period for air weapon systems. The objective is to determine if the value of RAM is sufficient in the field, and look for any difference from the target value to some extent. Methods : For a case study, the ${\bigcirc}{\bigcirc}$ training aircraft is selected. Data from the two acquisition sources are utilized. One is the operational data in domestic aircraft through research and development, and the other is the data from imported aircraft. The two different sources were collected independently and distinctly. Results : According to the analysis, the domestic aircraft shows high deviation in RAM value compare to the imported systems. This is due to the effort of continuous reliability improvement. In the aspect of maintainability, the result shows a slight deviation, and the availability meets the requirement. Conclusion : The results of this study can be used in finding a way that can be effectively applied to the sustainability in the weapon system. If the RAM performance is significantly lower than the target value, then it is necessary to improve the design activities so that they can achieve the RAM target value.

• Journal of the Korean Society for Railway
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• v.11 no.4
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• pp.371-377
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• 2008

As a railway is receiving attention as an environment-friendly transportation mode, many high speed, inter-city and urban railway are constructed and remodeled in the world. With this trend, railway RAMS was included in the international standard IEC 62278 in 2002. RAMS activity in domestic market is also increased with this international trend. However, IEC 62278 does not describe the methodology of substantial contents like how reliability target is set although it can be used as an overall guideline when RAMS requirements are included in the purchase specification. That is because RAMS requirements should be set with the specific railway condition. It is required to fully understand the meaning of railway RAMS parameters and apply those correspond to the specific railway system and environment condition especially when a quantitative RAMS requirement is set. In this study, the meaning and characteristics of RAMS parameters applicable to the development of quantitative RAMS requirement of rolling stock is described. And the basic concept of RAMS and the definition of failure that IEC 62278 describes is modified and suggested in order to make more suitable to the development of quantitative RAMS requirement.

• Journal of the Korean Society of Industry Convergence
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• v.26 no.5
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• pp.855-866
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• 2023

With the rapid advancement and sophistication of defense weapon systems, the government, military, and the defense industry have conducted various innovative attempts to improve the efficiency of post-logistics support(PLS). The Ministry of Defense has mandated RAM-C(Reliability, Availability, and Maintainability-Cost) analysis as a requirement according to revised Total Life Cycle System Management Code of Practice in May 2022. Especially, for the project budget forecast of new PBL(Performance Based Logistics) business contacts, RAM-C is recognized as an obligatory factor. However, relevant entities have not officially provided guidelines or manuals for RAM-C analysis, and each defense contractor conducts RAM-C analysis with different standards and methods to win PBL-related business contract. Hence, this study aims to contribute to the generalization of the analysis procedure by presenting a cost analysis case based on RAM-C for the supply of military depot maintenance PBL project. This study presents formulas and procedures to determine requirements of military depot maintenance PBL project for repair parts supply. Moreover, a sensitivity analysis was conducted to find the optimal cost/utilization ratio. During the process, a correlation was found between supply delay and total cost of ownership as well as between cost variability and utilization rate. The analysis results are expected to provide an important basis for the conceptualization of the cost analysis for the supply of military depot maintenance PBL project and are capable of proposing the optimal utilization rate in relation to cost.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.65 no.7
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• pp.1161-1168
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• 2016

Battery energy storage system(BESS) attract the attention of the power system operators with its fast response to a disturbance in spite of its limited energy capacity. This paper proposes the operating method of BESS for following the Automatic Generation Control(AGC) frequency control which is centrally distributed by a system operator. As BESS needs to just meet the control requirement from the system operator, it should be able to properly manage the state of charge(SOC) of BESS to be available to control signal. For doing these, the proposed method distributes the control requirement to available batteries in proportion to its SOC. In addition, unavailable batteries are controlled to recover the SOC to an appropriate range, and the recovering power is supplied by available batteries meeting the control requirement. Moreover, the proposed method manages the efficiency of power conversion system (PCS) by limiting the number of PCS to be assigned for the low control requirement. Finally, the case studies are carried out to verify the effectiveness of proposed strategy.