• 한국철도학회:학술대회논문집
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• 한국철도학회 2005년도 추계학술대회 논문집
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• pp.742-747
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• 2005

Electric railroad transformer of a supply of Operation power of DC electric cars is intense fluctuation of load and flows the only big short-circuit current as a accident of the power system. it is a peculiarity more severe than general power transformer. Consequently, researches the properties about the rectifier mold transformer of DC substation and applies with data of safety of the electric railroad transformer. This paper analyzed a failure mode, the accident occurrence scenario and the be latent dangerous unit against the rectifier mold transformer of DC railway system.

• Nuclear Engineering and Technology
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• 제38권3호
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• pp.231-238
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• 2006

Whole-body exposure to high-dose radiation causes injury involving multiple organs that depends on their sensitivity to radiation. This acute radiation syndrome (ARS) is caused by a brief exposure of a major part of the body to radiation at a relatively high dose rate. ARS is characterized by an initial prodromal stage, a latent symptom-free period, a critical or manifestation phase that usually takes one of four forms (three forms): hematologic, gastrointestinal, or cardiovascular and neurological (neurovascular), depending upon the exposure dose, and a recovery phase or death. One of the most important factors in treating victims exposed to radiation is the estimation of the exposure dose. When high-dose exposure is considered, initial dose estimation must be performed in order to make strategy decisions for treatment as soon as possible. Dose estimation can be based on onset and severity of prodromal symptoms, decline in absolute lymphocyte count post exposure, and chromosomal analysis of peripheral blood lymphocytes. Moreover, dose assessment on the basis of calculation from reconstruction of the radiation event may be required. Experience of a criticality accident occurring in 1999 at Tokai-mura, Japan, showed that ARS led to multiple organ failure (MOF). This article will review ARS and discuss the possible mechanisms of MOF developing from ARS.

• 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.

• 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.

• 전기학회논문지
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• 제66권9호
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• pp.1373-1378
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• 2017

This paper presents a basic ECU(Electronic Control Unit) hardware development procedure for the functional safety of in-vehicle network systems. We consider complete hardware redundancy as a safety mechanism for in-vehicle communication network under the assumption of the wired network failure such as disconnection of a CAN bus. An ESC (Electronic Stability Control) system is selected as an item and the required ASIL(Automotive Safety Integrity Level) for this item is assigned by performing the HARA(Hazard Analysis and Risk Assessment). The basic hardware architecture of the ESC system is designed with a microcontroller, passive components, and communication transceivers. The required ASIL for ESC system is shown to be satisfied with the designed safety mechanism by calculation of hardware architecture metrics such as the SPFM(Single Point Fault Metric) and the LFM(Latent Fault Metric).

• 한국안전학회지
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• 제34권6호
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• pp.58-64
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• 2019

Over the past decades there has been a growing body of researches that examines the psychological traits related to safety outcomes. After briefly reviewing the relationships between psychological dispositions and safety outcomes, we empirically examine the relationships with 2 samples of 1,102 participants. Fifteen psychological dispositions (big 5 personality, locus of control, cognitive failure, affection from job and relations, 4 achievement goal orientations, self-efficacy, fatigue, and depression) and four psychological outcomes (safe behavior, unsafe behavior, accidents, and injuries) are examined. After covariance structure modeling variances of safety outcomes are well explained by simple 4 dispositions of consciousness, mastery-approach goal orientation, self-efficacy, and depression. We name them 'core safety disposition', and name four psychological outcomes 'safety consciousness', and the relationships between those latent variables are stronger than between measurement variables. We propose core safety disposition as a cause of safety consciousness, and discuss implications for research and practices.

• 응용통계연구
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• 제11권2호
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• pp.377-387
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• 1998

컴퓨터의 발전에 따른 마코브체인 몬테카를로방법을 소프트웨어 신뢰확률모형에 이용하였다. 베이지안 추론에서 조건부분포를 가지고 사후분포를 결정하는데 있어서의 계산문제와 이론적인 정당성을 고려, 마코프연쇄와 메트로폴리스방법의 관계를 고찰하였으며, 특히 Mus-Okumoto와 Erlang(2)의 중첩모형에 대하여 깁스샘플링 알고리즘과 메트로폴리스 알고리즘을 활용하며 베이지안 계산과 예측 우도기준에 의 한 모형선택을 제안하고 Cox-Lewis에 의해 계시된 Thing method를 이용한 모의실험자료를 이용하여 수치적인 계산을 시행하고 그 결과가 제시되었다.

• 대한족부족관절학회지
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• 제26권1호
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• pp.9-15
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• 2022

Syndesmotic injuries are found frequently in clinical practice, and they remain controversial because of the variety of diagnostic techniques and management options. Bony avulsions or malleolar fractures are commonly associated with syndesmotic disruptions. Even unstable isolated syndesmosis injuries are associated with a latent or frank tibiofibular diastasis and should not be ignored in the early phase. A relevant instability of the syndesmosis with diastasis results from collateral ligaments tears and requires operative stabilization. The treatment involves an anatomic reduction of the distal tibiofibular articulations followed by stable fixation. Syndesmotic transfixation screws or suture button implants are being proposed as a means of fixation. Recently, suture button fixation has shown more favorable outcomes, but the outcomes can still be controversial. Syndesmotic malreduction can lead to hardware failure, adhesions, heterotopic ossification, tibiofibular synostosis, chronic instability, and posttraumatic arthritis. In particular, the correct diagnosis and evidence-based treatment options for unstable syndesmotic injury should be considered.

• 벤처창업연구
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• 제18권1호
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• pp.125-140
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• 2023

체계적인 창업 준비는 실패 가능성을 낮추고 시장성 있는 비즈니스 모델 수립을 가능하게 한다는 점에서 중장년 창업가에게 필수적이지만, 중장년의 창업준비를 위한 정책과 서비스는 충분히 활용되지 못하고 있다. 최근 중장년의 창업과 관련한 연구가 활발하게 수행되고 있으나 창업준비는 대학생이나 예비창업가를 중심으로 연구되어, 실제 창업을 한 중장년 창업가의 다양한 창업준비 행태를 심층적으로 분석한 연구는 부족하였다. 이에, 이 연구에서는 중장년 창업가의 창업준비 유형을 도출하고, 창업준비 유형에 따른 창업성과의 차이를 분석하고자 하였다. 이를 위해, 서울시 소재 업력 7년 미만 창업기업의 중장년 기술창업가 324명의 설문 데이터를 분석하였다. 중장년 기술창업가들의 창업준비는 보통 수준으로 창업 준비 기간의 충분성이 가장 높게 나타났으며, 창업교육을 통한 준비 수준이 가장 낮게 나타났다. 잠재프로파일 분석 결과 중장년 기술창업가들의 창업 준비 유형은 '전반적 부족형', '창업교육 소홀형', '포괄적 준비형'의 3개 집단으로 나타났다. 창업만족도, 창업역량, 실패 두려움, 창업서비스 접근성, 중장년 특화 지원 필요성에 대한 집단 별 차이 분석을 실시한 결과, 전반적 부족형에 비해 창업교육 소홀형과 포괄적 준비형의 창업만족도, 창업역량, 창업서비스 접근성이 통계적으로 유의하게 높은 것으로 나타났으며, 실패두려움의 경우 포괄적 준비형이 전반적 부족형과 창업교육 소홀형보다 통계적으로 유의하게 낮은 것으로 나타났다. 중장년 창업 서비스 접근성은 전반적 부족형이 타 집단보다 통계적으로 유의하게 낮게 나타났고, 중장년 특화 창업지원의 필요성은 모든 유형에서 높게 인식하고 있는 것으로 나타났다. 이러한 연구결과를 바탕으로 중장년의 체계적인 창업준비 지원을 위한 정책적 시사점은 첫째, 중장년층의 창업준비 수준을 향상할 수 있는 다양한 지원사업 확대 및 중장년 창업가의 창업준비 수준에 따른 유형별 지원 제공, 둘째, 중장년 창업지원 서비스에 대한 홍보와 접근성 강화, 셋째, 청년 창업가와 다른 중장년의 특성을 반영한 중장년 창업가 특화 교육 제공, 넷째, 창업교육을 포함한 창업준비의 여러 요인을 복합적으로 고려한 중장년 창업지원 제공 등으로 제시하였다.

• Strategy21
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• 통권30호
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• pp.236-262
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• 2012

Morgenthau claims that in international relations, there are the economic, political, and military powers that enable a nation to achieve its political and diplomatic goals. This paper explores the possibility of resolving international conflicts with naval power. First, the theoretical and historical perspective, naval power was used as a final resort to force a nation's political or diplomatic objective on an enemy nation when negotiations failed, and this was done through the physical and psychological destruction of the enemy by naval power. But as the use of military power has decreased because of the invention of the nuclear weapon, the existence of a large and capable navy deterrent has become one of the most useful military options among a nation's diplomatic measures. In other words, he focused on the political usefulness of naval power as a deterrent and coercive diplomatic tool for persuading other nations to acquiesce, rather than using naval power and actual military action as a final resort. The reason for this is that compared to army and air force, navy's flexibility, continuity, and the ability to deter are greater. The navy provides excellent accessibility through its wide mobility on the sea, and it has been shown through research that the navy possesses a political usefulness that facilitates the solution of conflicts through presence, naval intervention, and naval blockade. On the other hand, among the factors that could improve the influence of the navy are alliance relations, a reliable and powerful navy, carrots and sticks that it would have to deal with in the case of successful or unsuccessful negotiations, and support from international opinion. On this paper I introduce E.N.Luttwak's naval suasion theory. By the his theory, there are two mode of naval suasion. One is latent naval suasion the other is active suasion. Latent suasion there are deterrent mode and supportive mode. Active naval suasion there are coercive mode and supportive mode. Coercive mode has positive and negative. The limitations of naval suasion have been identified as follows. First, because the objective of the use of naval power is persuading enemy nations, the results are unpredictable. Second, the leaders of all countries possess limited understanding on the complexities of naval power and therefore lack understanding of the usefulness of naval power when choosing options. Third, in case of failure through naval suasion, prestige and reputation of a nation can be damaged. Finally, the following are additional possible research topic. First, a research on the decision making process of choosing naval power as a measure to resolve conflicts is needed. Lastly, research on the size of the navy and types of ships required for efficient naval suasion is needed. Today's world requires cooperative security regime so that middle class navy also requires political use of naval power in solving international conflicts. Therefore, additional research on this topic is needed.