• 한국산학기술학회논문지
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• 제17권8호
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• pp.379-388
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• 2016

현대 무기체계 제조를 위해 적용되는 수많은 생산 기술과 다양한 공정 환경으로 인해 다양한 결함이 무기체계 제조공정에 유입되고 있다. 이렇게 제조공정에 유입되는 결함 중 육안 검사, 기능 시험 등 기존 품질 관리 절차를 통해 검출할 수 있는 "명백결함(Patent Defect)"과 무기체계 복잡성과 제조공정의 복잡도로 기존 품질 관리 방식으로 검출이 제한되는 "잠재결함(Latent Defect)" 2가지 종류가 있다. 이러한 초기 결함 문제를 최소화하기 위해 무기체계 생산공정 중 유입된 결함요소를 환경부하(온도, 진동)를 활용하여 결함검출/제거/개선하기 위해 환경 부하 선별(ESS : Environmental Stress Screening) 시험을 수행해야 한다. 본 논문은 국내 무기체계 제조업체에서 정량적 환경 부하 선별 시험 설계의 어려움을 최소화하기 위해 MIL-HDBK-344(Environmental Stress Screening of Electronic Equipment)의 수학적 모델을 기반으로 정량적 환경 부하 선별시험 효과도 분석 및 프로파일 자동화 도구를 구현하였으며, 6가지(온도부하변수 3가지(온도범위/온도변화율/허용 잔류결함밀도), 진동부하변수 2가지(부하크기/허용 잔류결함밀도), 시험설계변수 1가지(허용 시험시간)) 시나리오를 통해 구현된 도구 유효성을 확인했다.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1999년도 하계학술대회 논문집 B
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• pp.871-873
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• 1999

According to the reports about the failure mode analysis of modules and systems, It is said that there are many early failure of system. To remove latent defects which causes early failures like that, It is necessary that screening test is performed. ESS is often used fur screening electronic equipments, and is proposed by the most powerful tool for removing latent defects of electronic equipments. [1][2] In this report, the procedure of the environmental stress screening which uses the temperature cycling stress is proposed. It is considered about environmental conditions of distributed control system(DCS) to be tested, design specifications of the system, recommended conditions of relative IEC-STD and applied conditions of similar company. ESS test was applied at the DCS to be installed in power plant. As the results of analyzing discovered problems. It was found that almost latent defects of electronic control systems was discovered early.

• 품질경영학회지
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• 제43권3호
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• pp.273-288
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• 2015

Purpose: In this study, we apply environmental stress screening (ESS) to battle management system (BMS) of a tank and use the ESS profile based on production process data, guided by MIL-HDBK-781/344/2164. Methods: To optimize ESS Profile of the BMS of a tank, we estimate ESS model parameters (e.g., defect density, screening strength) using primary production failure reporting and corrective action system (FRACAS) data of military supply contract firm. Results: First, we collect the Primary production FRACAS data of military supply contract firm. Second, we compute curve fitting approach to find patent defect density and latent defect density using FRACAS data. Third, we solve the equation of Defect Density(patent defect density + latent defect density)($D_{IN}$) and Screening Strength(SS) Using second step data. As a result of analysis according to the order, we calculate $D_{IN}$(Temperature stress case : 74.02, Vibration stress : 10.252) and : SS(Temperature stress case : 0.4632, Vibration stress : 0.4142) and confirm the Condition II-D based on MIL-HDBK-344. According to Condition II-D, it is necessary to modify existing ESS profile through decreasing the $D_{IN}$ and increasing the SS. Conclusion: Identification of defect causes through ESS approach reduce defect densities for production. It provides feedback to a lessons-learned data base to avoid similar problems on next generation tank BMS.

• 한국신뢰성학회:학술대회논문집
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• 한국신뢰성학회 2001년도 정기학술대회
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• pp.273-275
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• 2001

With the continuous advancement in electronics technology, especially the usage of new materials and the introduction of new and immature manufacturing process, stress and time dependent types of physical, chemical and mechanical imperfections are introduced to the electronic hardware. These types of imperfections are called flaws. A reliability stress screening process(RSS) is a process which involves the application of operational and/or environmental stress to electronic hardware on a 100% basis, for the purpose of precipitating inherent, as well as process-induced, flaws while neither destroying nor degrading in a significant way the hardware being stressed.

• 한국신뢰성학회지:신뢰성응용연구
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• 제18권3호
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• pp.229-239
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• 2018

Purpose: There is a difficulty in Environmental Stress Screening (ESS) test design for weapon system's electrical/electronic components/products in small and medium-sized enterprises. To overcome this difficulty, I propose an easy ESS test design approach algorithm that is optimized with only one environment tolerance design information parameter (${\Delta}T$). Methods: To propose the mass production weapon system ESS test design for cost-effective optimization, I define an optimum cost-effective mathematical model ESS test algorithm model based on modified MIL-HDBK-344, MIL-HDBK-2164 and DTIC Technical Report 2477. Results: I clearly confirmed and obtained the quantitative data of ESS effectiveness and cost optimization along our ESS test design algorithm through the practical case. I will expect that proposed ESS test method is used for ESS process improvement activity and cost cutting of mass production weapon system manufacturing cost in small and medium-sized enterprises. Conclusion: In order to compare the effectiveness of the proposed algorithm, I compared the effectiveness of the existing ESS test and the proposed algorithm ESS test based on the existing weapon system circuit card assembly for signal processing. As a result of the comparison, it was confirmed that the test time was reduced from 573.0 minutes to 517.2minutes (9.74% less than existing test time).

• 한국환경성돌연변이발암원학회:학술대회논문집
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• 한국환경성돌연변이발암원학회 2003년도 춘계학술대회
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• pp.66-67
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• 2003

• 한국항행학회논문지
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• 제25권5호
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• pp.313-319
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• 2021

본 논문에서는 MIL-HDBK-344A 기반의 ESS(environmental stress screening) 시험 에 대해 소개하고, 유도탄 내부 케이블의 ESS 시험에 대한 목적과 규격 설정 및 시험 방안에 대하여 확인하였다. ESS 시험구성은 온도 순환과 랜덤 진동의 환경 자극으로 이루어져 있으며, 핸드북의 절차를 기반으로 유도탄 내부 케이블의 ESS 시험 규격 설정과 시험 구성을 제시하고, 진동 시험을 위한 유도탄 내부 케이블의 ESS 시험을 위한 치구를 제작하였다. 스크린 강도(SS; screening strength)를 통해 결정되는 결함 감지 확률은 일회성으로 사용되는 유도탄의 신뢰성에 부합되도록 선정하였고, 또한 ESS 시험 중 유도탄 내부 케이블의 검사방법과 고려해야 할 점에 대하여 소개하였다.

• 한국독성학회:학술대회논문집
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• 한국독성학회 2003년도 춘계학술대회 논문집
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• pp.66-67
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• 2003

It is well known that osteoblasts and osteoc1asts playa key role in bone metabolism. They involve in osteoformation or bone destruction which are ragulated by various factors such as thyroid hormone, parathyroid hormone, estrogen, growth factor and cytokine. Recently, it is demonstrated that oxidative stress is one of pathological factors in bone metabolism, but it is left unknown about mechanism between oxidative stress and bone metabolism.(omitted)

• BMB Reports
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• 제41권3호
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• pp.259-265
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• 2008

Three peroxidase (POD) cDNAs were isolated from dehydration-treated fibrous roots of sweetpotato (Ipomoea batatas) plant via the screening of a cDNA library, and their expressions were assessed to characterize functions of each POD in relation to environmental stress. Three PODs were divided into two groups, designated the basic PODs (swpb4, swpb5) and the anionic PODs (swpa7), on the basis of the pI values of mature proteins. Fluorescence microscope analysis indicated that three PODs are secreted into the extracellular space. RT-PCR analysis revealed that POD genes have diverse expression patterns in a variety of plant tissues. Swpb4 was abundantly expressed in stem tissues, whereas the expression levels of swpb5 and swpa7 transcripts were high in fibrous and thick pigmented roots. Swpb4 and swpa7 showed abundant expression levels in suspension cultured cells. Three POD genes responded differently in the leaf and fibrous roots in response to a variety of stresses including dehydration, temperature stress, stress-associated chemicals, and pathogenic bacteria.

• 한국전자통신학회논문지
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• 제15권2호
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• pp.335-342
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• 2020

ESS(초기고장배제)는 제품생산 간 유입되는 '잠재결함'을 제거하기 위한 중요한 생산 프로세스로서 최근에는 방위사업 분야에서도 제품에 대한 필수 품질요구조건으로서 QAR(품질보증요구서)에 포함되고 있으나, 무기체계의 분류 및 작성자에 따라 내용 및 작성양식이 상이하거나, 중요한 요소가 누락되는 사례가 빈번하게 식별되고 있다. 따라서 본 논문에서는 MIL-HDBK-344A 기반의 정량적인 ESS 요구사항 표준안을 제시하여 QAR의 일관성 및 완전성을 보장하고, 잠재결함 제거 효과 파악을 위한 지표인 결함유도효율(PE) 산출 시 용이성을 확보하고자 한다.