• 한국정보통신학회논문지
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• 제21권11호
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• pp.2191-2198
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• 2017

군 무기체계의 성능을 점검하기 위해 사용되는 정밀측정장비는 수명주기 동안 측정신뢰도 유지를 위해 주기적으로 교정된다. 기존의 교정주기 관련 연구들은 장비의 샘플 크기와 특성을 고려하여 측정신뢰도 모델을 결정할 것을 제안하고 있으나, 다양한 정밀측정장비의 정비 데이터에 동일한 특성 분포를 가정하고 단일 모델을 적용하는 것은 적합하지 않을 수 있다. 본 논문에서는 정밀측정장비의 수명주기 동안 욕조 곡선의 특성을 가정하여 측정신뢰도 모델들로부터 추정된 교정주기 가운데 F-검정과 성능지수 평가를 통해 정비 데이터에 가장 적합한 교정주기가 선택되도록 제안하였다. 제안한 방법을 다양한 장비에 적용한 결과 교정주기 동안 장비의 신뢰도가 유지됨을 확인하였다.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2001년도 춘계학술대회 논문집
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• pp.613-617
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• 2001

The test items like as endurance, air leakage and oil endurance test is requested for reliability evaluation about O-ring which is a kind of core machinery accessories of semi-conduct manufacturing equipment. For verification of these, we design and manufactured a test system for endurance, air leakage and oil endurance of O-ring for semi-conduct manufacturing equipment, and also performed the test for two kinds of O-ring, as it were Viton and Kalretz. The characteristics of this test equipment consist in realization of the test conditions of semi-conduct manufacturing equipment and satisfying the test method. The test conditions are cut gas, vacuum grade, temperature and revolution numbers in the endurance test system, vacuum grade and temperature in the air leakage test system, temperature and time in the oil endurance test system. The separating test results for wearing which is an oil endurance test item, the wearing index of domestic produced Viton O-ring is higher than foreign product by 2%, wearing rate of Kalretz O-ring better than Viton O-ring by 17%, and particles existed in various place. The test result of air leakage which is measured through the RGA sensor used Helium, the vacuum grade was $10^-3$Torr. And the test result of oil endurance, the volume change rate was 7~15%. Hereafter, we intend to analysis the reliability test evaluation and to utilize for domestic manufacturing companies by establishing data base and developing reliability softwares.

• 항공우주시스템공학회지
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• 제10권2호
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• pp.1-6
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• 2016

The thermal analysis of electronic equipment is required to predict the reliability of electronic equipment being loaded on a satellite. The transient heat transfer of electronic equipment that was developed recently has been generated using a large-scale integration circuit. If there is a transient heat transfer between EEE(Electric, Electronic and Electro mechanical) parts, it may lead to failure the satellite mission. In this study, we performed the thermal design and analysis for reliability of APD(Antenna Pointing Driver) electronics for activation of a spaceborne X-band 2-axis antenna. The EEE parts were designed using a thermal mathematical model without the thermal mitigation element. In addition, thermal analysis was performed based on the worst case for verifying the reliability of EEE parts. For the thermal analysis results, the thermal stability of electronic equipment has been demonstrated by satisfying the de-rating junction temperature.

• 한국정보통신학회:학술대회논문집
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• 한국정보통신학회 2017년도 춘계학술대회
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• pp.383-386
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• 2017

임베디드 시스템의 일종인 항공전자 장비는 높은 안전성과 신뢰도를 요구한다. 항공전자 장비 고장은 항공기 운용에 중대한 영향을 미칠 뿐만 아니라 최악의 경우에는 조종사와 승객의 인명 손실을 초래할 수도 있다. 본 논문에서는 항공전자 장비의 신뢰도를 높이기 위해 장비에 발생 가능한 고장을 사전에 감지할 수 있는 Built-In-Test(이하: BIT) 설계 기법과 장비의 Mean Time Between Failure(이하: MTBF)를 향상시킬 수 있는 설계 방법을 연구하고 실제 항공전자 장비에 적용하여 신뢰도를 향상시킨 사례를 소개한다.

• 드라이브 ㆍ 컨트롤
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• 제15권4호
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• pp.48-54
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• 2018

The hydraulic servo actuator has always operated very precisely with high frequency and small displacement, and is used continuously for a long time. The hydraulic servo actuator of the test equipment used in the accelerated life test in order to guarantee the service life of the automotive parts failed earlier than the products before finishing the test. This study performed an analysis on the cause of the failure of the hydraulic servo actuator used in the test equipment, changed the design of the actuator to solve the root cause of the main failure mode, and developed the improved servo actuator. Based on above process, this study established a better performances and longer lifetime of the servo actuator after testing.

• 전자공학회논문지
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• 제51권10호
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• pp.228-234
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• 2014

건설 중장비의 경우 유압기기 및 전장 배선 등으로 인하여 내부의 배선이 매우 복잡한 구조를 가지고 있으며, 이러한 복잡한 배선으로 인하여 장비의 생산 및 유지 보수에 많은 시간이 소요되고 있어 원가 상승 요인으로 작용한다. 본 논문에서는 건설 중장비의 전장 배선을 간소화하기 위한 고신뢰성을 갖는 PLC(Power Line Communication)-CAN(Controller Area Network) 통신 모듈을 설계하고 구현한다.

• 대한기계학회논문집A
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• 제39권9호
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• pp.871-877
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• 2015

다양한 기계부품과 센서류가 포함된 수중로봇, 무인 잠수정 등과 같은 심해장비 시스템은 수심에 따른 높은 수압과 온도, 조류 등 심해의 복합적인 극한 환경조건의 영향을 받기 때문에 실제 현장에서 사용되기 전에 제품의 신뢰성을 검증하는 것이 매우 중요하다. 이러한 복합적인 해양환경을 재현하여 제품에 대한 실증적인 시험을 할 수 있는 시험장비의 구축이 요구되는 실정이다. 본 연구를 통하여 최대수압 2.0MPa, 수온 $5{\sim}60^{\circ}C$, 최대유속 2 m/s의 복합 환경조건의 구현이 가능한 워크인 타입의 수중복합 환경시험장비를 구성하는 주요 구성품의 개발 요구사양 및 설계방안을 제시하고 이를 통해 심해장비 시스템 및 모듈 부품에 대한 제품 신뢰도를 검증할 수 있는 시험장비의 개발 내용을 제시하고자 한다.

• 품질경영학회지
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• 제49권3호
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• pp.341-358
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• 2021

Purpose: After product development, a Reliability Demonstration Test(RDT) is performed to confirm that the target life has been achieved. In the RDT, there are cases where the test equipment cannot accommodate all samples. Therefore, this study considers a test method to most economically demonstrate the target life of the product at a certain confidence level when the sample size is larger than the capacity of the test equipment. Methods: If the sample size is larger than the capacity of the test equipment, test equipments may be added or the test time of individual samples may be increased. So the test method is designed to cover this situation with limited capacity. A zero-failure test method is applied as a test method to RDT. To minimize the cost, the test cost is defined and the cost function is obtained. Finally, we obtain the optimal test plan. Results: A zero-failure test method is designed when the sample size is larger than the capacity of the test equipment, and the expected total cost is derived. In addition, the process of calculating the appropriate sample size, test time, and number of test equipment is illustrated through an example, and the effects of model parameters to the optimal solutions are investigated numerically. Conclusion: In this paper, we study a zero-failure RDT with test equipment that has limited capacity. The expected total cost is derived and the optimal sample size, test time, and number of test equipment are determined to minimize the expected total cost. We also studied numerical examples and for further studies, we can relax some restrictions in the test model and optimize the test method.

• 대한안전경영과학회지
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• 제6권2호
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• pp.231-239
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• 2004

To keep an enterprise's competitiveness on the condition of the automatic manufacturing system such as FA, FMS and CIM, all the maintenance problems should be considered seriously in not only in production and maintenance but also in related industrial productivity. This paper presents the study of equipment reliability improvement for rotary-machine vibration analysis. Based on these analyses, the maintenance management information system, and the machinery condition diagnosis technique are studied by using of the real-time diagnostic. Therefore, it is expected to improve the efficiency of business processes in the production and safety when we use this system.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2001년도 하계학술대회 논문집
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• pp.207-210
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• 2001

Electrical equipment for railway is always experiencing wear and degradation by mechanical, electrical and environmental stress in service and the fault or the accident of high voltage main circuit directly causes operation interruption. Particularly propulsion drive of high speed switching inverter takes the form of specific degradation mechanism such as fast rising transient surge, reflective overvoltage and harmonic stress, and it is known that it threatens the long life and the reliability of electrical equipment. In this paper, statistics of fault and accident on main electrical equipment for railway are presented and also insulation degradation mechanism, which governs end life of electrical device, is analyzed. Finally the method of fault respondence and reliability improvement on the main electrical equipments will be reviewed in order to prevent operation interruption.