• 산업경영시스템학회지
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• 제24권67호
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• pp.69-76
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• 2001

In order to review the failure rate of PC monitor under normal environmental conditions, we experimented for various levels of each factors, e.g. Power on/off, DPM mode, using voltage incoming Surge, Torque strength etc. According to the results of experiment and SN ratios we investigated that the causes of the failure for the horizontal output TR of monitor are Mode change, dispersion of Torque and $h_{FE}$ and these are critical effect. For the new reliability test we suggested that strengthened part tests in IQC branch, Torque change controls in the TR specification are necessary.

• Nuclear Engineering and Technology
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• 제51권1호
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• pp.45-53
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• 2019

Thermal-hydraulic passive safety systems (PSSs) are incorporated into many advanced reactor designs on the bases of simplicity, economics and inherent safety nature. Several factors among which are the critical parameters (CPs) that influence failure and reliability of thermal-hydraulic (t-h) passive systems are now being explored. For simplicity, it is assumed in most reliability analyses that the CPs are independent whereas in practice this assumption is not always valid. There is need to critically examine the dependency influence of the CPs on reliability of the t-h passive systems at design stage and in operation to guarantee safety/better performance. In this paper, two multivariate analysis methods (covariance and conditional subjective probability density function) were presented and applied to a simple PSS. The methods followed a generalized procedure for evaluating t-h reliability based on dependency consideration. A passively water-cooled steam generator was used to demonstrate the dependency of the identified key CPs using the methods. The results obtained from the methods are in agreement and justified the need to consider the dependency of CPs in t-h reliability. For dependable t-h reliability, it is advisable to adopt all possible CPs and apply suitable multivariate method in dependency consideration of CPs among other factors.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2006년도 추계학술대회 논문집
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• pp.1501-1507
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• 2006

The accidents are often resulted from multiple causes with hardware failure and human errors. So to ensure the safety of rail operation, human error should be prevented effectively. The purpose of this paper is to present an analysis system on factors of influencing human error in korean rail industry especially for engine driver and train despatcher. To achieve it, ESFs(error shaping factors) classification system was derived from several PSFs(performance shaping factors) classification system. Based on them, two kinds of questionnaires for engine driver and train despatcher each were developed. Then Analytic Hierarchy Process (AHP) methodology was used to evaluate what factors were critical to human error.

• 마케팅과학연구
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• 제15권2호
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• pp.123-140
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• 2005

본 연구는 메가 이벤트 도입에 있어 지역주민들과의 갈등 원인과 거주민의 인구특성과의 관계 그리고 라이프스타일에 따른 주민들의 지각차이를 부정적 지각을 중심으로 도입저해 요인을 탐색하였다. 그 결과 자동차 경주 도입 거부요인으로 도시환경, 생활환경, 교육환경, 지역산업환경, 그리고 관광산업환경으로 나타났다. 이 중 교육환경과 도시환경이 가장 중요한 거부요인으로 밝혀졌다. 인구통계적 특성과 거주지 및 직장위치, 그리고 개인의 라이프스타일에 따라 자동차 경주 도입의 거부에 대한 지각이 다르게 나타났다. 또한 지역주민들이 우려하는 환경요인을 라이프스타일 유형에 따라 분석하여, 자아과다통제형, 자아탄력적통제형, 자아과소통제형에 따라 서로 상이한 지각이 행사됨을 밝혔다.

• 한국콘텐츠학회논문지
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• 제9권12호
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• pp.600-612
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• 2009

최근 들어 설립 가능성이 높아지고 있는 인터넷전문은행은 고객과의 거래행태, 위험관리, 자본력, 지점 네트워크 등에서 일반은행과 상이한 특성을 가지고 있다. 이러한 인터넷전문은행의 성공 및 실패요인에 대해 기존 연구에서는 조직 생태학적 관점에 기반하여 규모의 경제와 학습 효과로만 설명하고 있다. 본 연구에서는 이러한 조직 생택학적 관점 대신에 조직의 전략적 선택 관점과 자원 기반 관점에 근거하여 인터넷전문은행의 성공요인을 도출하고자 하였다. 이를 위해 해외의 주요 인터넷전문은행 31개를 대상으로 은행의 규모와 수익성에 따라 구분하여 3개의 전략그룹을 도출하였으며, 각각의 전략그룹을 대표하는 기업 사례를 심층 분석하였다. 다중사례분석 결과, 인터넷전문은행의 주요성공요인이 도출되었으며, 국내 도입시 고려해 야 할 요인에 대한 논의가 이루어졌다.

• 한국농공학회지
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• 제32권4호
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• pp.71-80
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• 1990

Model tests for the ultimate pullout resistance of anchorages and investigation of failure behaviors in cohesionless soil have been conducted. The factors affecting the anchorage are mostly the geometry of the system, and soil properties of sands. The main conclusions of the experimental work were as follows. 1. The load - displacement relationship can be a form of parabolic curve for all plates. 2. The change in ultimate pullout resistance of anchor is mostly affected by embedment ratio and size of anchor, and influenced to a lesser degree by its shape. 3. Critical embedment ratio which is defined as the failure mode changes from shallow to deep mode is increased with increasing height of anchor. 4. For a constant anchor height, as the width of anchor increases the ultimate pullout resistance also increases. However, considering the efficiency of anchor for unit area, width of anchor does not appear to have any sigrnificant contribution on increasing anchor city. 5. Anchor capacity has a linear relation to sand density for any given section and the rate of change increases as the section increases. Critical depth determining the failure patterns of anchor is decreased with a decrease of sand density. 6. With increasing inclination angle, size of anchor, and decreasing embedment ratio, the ultimate pullout resistance of anchor under inclined loading is significantly decreased. 7. The ultimate pullout resistance of double anchor, a method of improving single of anchor capacity, is influenced by the center - to - center spacing adjacent anchors. It is also found that tandem and parallel anchor rigging arrangements decrease the anchor system capacity to less than twice the single anchor capacity due to anchor interference.

• 한국건설관리학회논문집
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• 제7권5호
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• pp.177-190
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• 2006

Construction projects are facing delay problems. Delays in construction have been immense effect on performance or satisfactory delivery of the project. Delays have been causing project cost overrun as well as it is a source of dispute hence damaging the relationship between the project participants. The purpose of this study was to explore the causes of delay risk through a field survey study. Data were collected from construction professionals working in owner, consultant and contractor organizations. All together 208 questionnaire instruments were used and analyzed by employing statistical tools (SPSS computer program). 19 delay factors were identified by this study, out of which following factors were critical: Frequent interruptions from public (local people, pressure group etc.), changed site condition, failure to provide required construction site, unrealistic project time estimation and design errors.

• Steel and Composite Structures
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• 제29권4호
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• pp.437-450
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• 2018

A bridge comprising of two girders, such as a twin steel box-girder bridge, is classified as fracture critical (i.e., non-redundant). In this study, the various bridge components of the twin steel box-girder bridge are investigated to determine if these could be utilized to improve bridge redundancy. Detailed finite-element (FE) models, capable of simulating prominent failure modes observed in a full-scale bridge fracture test, are utilized to evaluate the contributions of the bridge components on the ultimate behavior and redundancy of the bridge sustaining a fracture on one of its girders. The FE models incorporate material nonlinearities of the steel and concrete members, and are capable of capturing the effects of the stud connection failure and railing contact. Analysis results show that the increased tensile strength of the stud connection and (or) concrete strength are effective in improving bridge redundancy. By modulating these factors, redundancy could be significantly enhanced to the extent that the bridge may be excluded from its fracture critical designation.

• Steel and Composite Structures
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• 제47권2호
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• pp.269-287
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• 2023

The WGJ420 fire-resistant weathering (FRW) steel is developed and manufactured with standard yield strength of 420 MPa at room temperature, which is expected to significantly enhance the performance of steel structures with excellent fire and corrosion resistances, strong seismic capacity, high strength and ductility, good resilience and robustness. In this paper, the mechanical properties of FRW steel plates and buckling behavior of columns are investigated through tests at elevated temperatures. The stress-strain curves, mechanical properties of FRW steel such as modulus of elasticity, proof strength, tensile strength, as well as corresponding reduction factors are obtained and discussed. The recommended constitutive model based on the Ramberg-Osgood relationship, as well as the relevant formulas for mechanical properties are proposed, which provide fundamental mechanical parameters and references. A total of 12 FRW steel welded I-section columns with different slenderness ratios and buckling load ratios are tested under standard fire to understand the global buckling behavior in-depth. The influences of boundary conditions on the buckling failure modes as well as the critical temperatures are also investigated. In addition, the temperature distributions at different sections/locations of the columns are obtained. It is found that the buckling deformation curve can be divided into four stages: initial expansion stage, stable stage, compression stage and failure stage. The fire test results concluded that the residual buckling capacities of FRW steel columns are substantially higher than the conventional steel columns at elevated temperatures. Furthermore, the numerical results show good agreement with the fire test results in terms of the critical temperature and maximum axial elongation. Finally, the critical temperatures between the numerical results and various code/standard curves (GB 51249, Eurocode 3, AS 4100, BS 5950 and AISC) are compared and verified both in the buckling resistance domain and in the temperature domain. It is demonstrated that the FRW steel columns have sufficient safety redundancy for fire resistance when they are designed according to current codes or standards.

• 기술사
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• 제41권2호
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• pp.64-67
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• 2008

According to grow maritime activities in coastal zone, a threat increase to the marine environment from oil spill. The success or failure of initial effort depends on the adequacy of the plan and the ability of immediate execution. Successful response to oil spills requires critical information in real time topics, including spill data, environmental conditions, ecological factors. Diverse simulation provides tactical decision-makers with the information on the movement of pollutant.