• 산업경영시스템학회지
• /
• 제39권4호
• /
• pp.49-59
• /
• 2016

Naval combat system developed in-country is progressing at an alarming rate since 2000. ROK navy will be achieved all vessels that have combat system in the near future. The importance of System Engineering and Integrated Logistics Support based on reliability analysis is increasing. However, reliability analysis that everyone trusted and recognized is not enough and applied practically for development of Defense Acquisition Program. In particular, Existing Reliability Analysis is focusing on reliability index (Mean Time Between Failure (MTBF) etc.) for policy decision of defense improvement project. Most of the weapon system acquisition process applying in the exponential distribution simply persist unreality due to memoryless property. Critical failures are more important than simple faults to ship's operator. There are no confirmed cases of reliability analysis involved with critical failure that naval ship scheduler and operator concerned sensitively. Therefore, this study is focusing on Mean Time To Critical Failure (MTTCF), reliability on specific time and Operational Readiness Float (ORF) requirements related to critical failure of Patrol Killer Guided missile (PKG) combat system that is beginning of naval combat system developed in-country. Methods of analysis is applied parametric and non-parametric statistical techniques. It is compared to the estimates and proposed applications. The result of study shows that parametric and non-parametric estimators should be applied differently depending on purpose of utilization based on test of normality. For the first time, this study is offering Reliability of ROK Naval combat system to stakeholders involved with defense improvement project. Decision makers of defense improvement project have to active support and effort in this area for improvement of System Engineering.

• 산업공학
• /
• 제23권2호
• /
• pp.147-155
• /
• 2010

Reliability allocation is defined as a problem of determination of the reliability for subsystems and components to achieve target system reliability. The determination of both optimal component reliability and the number of component redundancy allowing mixed components to maximize the system reliability under resource constraints is called reliability-redundancy allocation problem(RAP). The main objective of this study is to suggest a mathematical programming model and a hybrid parallel genetic algorithm(HPGA) for reliability-redundancy allocation problem that decides both optimal component reliability and the number of component redundancy to maximize the system reliability under cost and weight constraints. The global optimal solutions of each example are obtained by using CPLEX 11.1. The component structure, reliability, cost, and weight were computed by using HPGA and compared the results of existing metaheuristic such as Genetic Algoritm(GA), Tabu Search(TS), Ant Colony Optimization(ACO), Immune Algorithm(IA) and also evaluated performance of HPGA. The result of suggested algorithm gives the same or better solutions when compared with existing algorithms, because the suggested algorithm could paratactically evolved by operating several sub-populations and improve solution through swap, 2-opt, and interchange processes. In order to calculate the improvement of reliability for existing studies and suggested algorithm, a maximum possible improvement(MPI) was applied in this study.

• 한국신뢰성학회:학술대회논문집
• /
• 한국신뢰성학회 2001년도 정기학술대회
• /
• pp.289-289
• /
• 2001

Experimental design has become one of the primary tools for achieving quality of manufactured products. Because of a devision in the diciplines of quality and reliability, this important tool has not been used to extensively to achieve reliability. In this talk, we describe how experimental design can be used to achieve reliability.

• 전기학회논문지P
• /
• 제64권4호
• /
• pp.251-255
• /
• 2015

Chiller system plays an important role of maintaining room temperature constantly by supplying chilled water to Heating, Ventilating and Air Conditioning(HVAC)or area room cooler equipment during plant normal operation or accident condition. Chiller failures are one of the most frequently occurring equipment failures. If the types of chiller failures are analyzed and grouped thoroughly, it would be helpful to make chiller maintenance strategy at the plants. That would enhance equipment reliability of chiller in the end. In this paper, chiller failure data during three years were analyzed and categorized by specific failure code. In addition, the various proposals to improve equipment reliability of chiller were suggested such as Preventive Maintenance Optimization(PMO) strategy and performance monitoring reinforcement and so on.

• 동력기계공학회지
• /
• 제16권6호
• /
• pp.59-65
• /
• 2012

Torque Generator is a product which has function to transform hydraulic energy to mechanical energy of torque and rotating speed, and be used for direction change device of agricultural machines. This study proposes failure analysis and test analysis on torque generator and introduces a process that reliability of a product is enhanced by design improvement. And also it presents improvements of maximum output torque by modifying design and surface treatment. Lastly it verifies reliability improvement by analyzing test results of before and after life test.

• 한국품질경영학회:학술대회논문집
• /
• 한국품질경영학회 2004년도 품질경영모델을 통한 가치 창출
• /
• pp.272-277
• /
• 2004

Recently reliability Improvement and certification are considered as important issues by world-wide leading and highly qualified companies in advanced countries. In Korea, from a few years ago, the policy for reliability certification newly has been driven to improve product competitiveness in part and material industry. As yet the reliability certification is local and domestic, it is necessary to develop local certification system to global certification system. Reliability certification system is composed of accreditation body, testing laboratory and reliability assurance. In this paper, we review the reliability certification system and its application in Korea and the current research trends in advanced countries. Finally we propose some suggestions for the eliability certification system to be an international standard.

• 한국신뢰성학회지:신뢰성응용연구
• /
• 제4권1호
• /
• pp.27-37
• /
• 2004

In this paper, we propose a framework of reliability education program for industry people taking charge of reliability improvement or reliability evaluation. To this end, we investigate the situation of how reliability theories or reliability technologies are applied to industry and how industry people have reliability educations. And we also identify reliability theories or technologies which industry people need to ensure. Based on the result of such studies, we design a reliability education program which is appropriate for industry people.

• 한국신뢰성학회:학술대회논문집
• /
• 한국신뢰성학회 2004년도 정기학술대회
• /
• pp.269-280
• /
• 2004

In this paper, we propose a framework of reliability education program for industry people taking charge of reliability improvement or reliability evaluation. To this end, we investigate the situation of how reliability theories or reliability technologies are applied to industry and how industry people have reliability educations. And we also identify reliability theory or technology which industry people need to ensure. Based on the result of such studies, we design a reliability education program which is appropriate for industry people.

• 대한기계학회:학술대회논문집
• /
• 대한기계학회 2007년도 춘계학술대회A
• /
• pp.1712-1717
• /
• 2007

This paper presents a derating design approach for reliability improvement of an aluminum electrolytic capacitor. The capacitor, usually mounted in a printed circuit board, is used to stabilize the circuit. The main failure mechanism of interest is dry-up of the electrolyte that is mainly caused by two stresses-temperature and voltage. The lifetime under these stresses is modeled as a function of these stresses and time using accelerated life testing. Quantitative variation in the lifetime, according to variations in these stresses, is investigated to perform the derating design of the capacitor so that the stress levels are selected to achieve required reliability measures for reliability improvement. Moreover, sensitivity analysis shows which stress would be a more important factor determining the lifetime.

• 정보처리학회논문지:소프트웨어 및 데이터공학
• /
• 제3권10호
• /
• pp.389-396
• /
• 2014

프로젝트 수행은 많은 결함을 내포하고 있다. 특히 유사한 분야의 프로젝트 수행 경험이 없다면 결함은 전체 시스템에 많은 영향을 주게 된다. 따라서 이와 같은 결함은 프로젝트의 성공 여부를 판단할 수 있는 중요한 요소가 된다. 결국 효율적인 위험관리는 문제에 쉽게 대처할 수 있게 해주며, 예상하지 못한 품질, 예산초과 및 일정 지연이 되지 않도록 해준다. 본 연구에서는 소프트웨어 개발 시, 프로세스의 신뢰성 향상을 위하여 체크포인트를 제시하고 이를 활용하여 전체 시스템의 신뢰성을 향상하고자 한다.