• 해양환경안전학회:학술대회논문집
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• 해양환경안전학회 2003년도 추계학술발표회
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• pp.7-11
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• 2003

선박충돌사고는 많은 원인이 서로 복잡하게 상호작용을 하여 발생하고 있으며, 특히 인적요인에 의한 충돌사고가 가장 큰 비중을 차지하고 있다. 이러한 선박충돌사고 원인분석은 선박의 안전 운항상의 측면에서 매우 중요하다고 할 수 있다. 따라서 본 연구의 목적은 시스템다이내믹스법을 이용하여 선박충돌사고 인적요인 모델을 구축하고, 선박충돌사고를 감소시키기 위한 가장 효과적인 대책을 수립하기 위한 정책요소론 제시하고자 한다. 본 연구의 수행을 위해 ]nM법에 의한 충돌사고원인의 구조분석을 인과지도상의 정량적, 정성적, 피드백 루프로 변환하였다. 그리고 표준시뮬레이션모델과 8가지 정책시뮬레이션모델을 20년간(1993-2012) 시뮬레이션을 수행하였다.

• 한국건설관리학회:학술대회논문집
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• 한국건설관리학회 2003년도 학술대회지
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• pp.373-378
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• 2003

최근 우리 해외건설시장은 이라크전쟁 발발 둥에 의한 외적요인과 수주경쟁력 하락 등에 의한 내적요인으로 인해 해외 수주량이 격감되고 있을 뿐만 아니라, 수익성 악화라는 이중고에서 벗어나지 못하고 있다. 해외건설공사는 그 특성상 다양한 리스크를 포함하고 있을 뿐만 아니라 최근 수주비중이 크게 증가하고 있는 플랜트공사를 중심으로 보다 높은 수준의 관리능력을 요구하고 있기 때문에, 국내 건설업체들이 해외건설시장에서 생존하기 위해서는 입찰초기 단계에서부터 양호한 프로젝트를 선별하여 집중 수주하고, 리스크가 상대적으로 높은 프로젝트는 그 원인을 분석하여 계약서 등에 이를 완화시킬 수 있는 조항을 반영할 수 있는 지의 여부를 철저히 검증하는 전략을 수립할 필요가 있다. 따라서 본 연구에서는 국내건설업체가 참여한 해외건설공사 59건을 대상으로 수익성 영향인자를 도출하고 이들 간의 인과관계(cause-and-effect)를 계층화하여, 해외공사 참여자들이 공사 전(前) 단계에서 보다 체계적으로 리스크를 예측${\cdot}$분석할 수 있는 평가기준을 제공하고자 한다. 이러한 수익성 영향인자 계층구조는 해외건설공사를 수행하는데 있어 고려해야 할 수익성 인자들의 유형은 무엇이고 다양한 상위인자 및 하위인자들이 어떻게 관련되어 있는지를 나타내며, 또 계층구조를 정성적으로 분석함으로써 공사 관리자들이 중점 관리해야 하는 수익성 악화 요인과 이들 간의 관계를 유추할 수 있다.

• 한국압력기기공학회 논문집
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• 제6권1호
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• pp.50-56
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• 2010

Fatigue has been known as a major degradation mechanism of ASME class 1 components in nuclear power plants. Fatigue damage could be accelerated by combined interaction of several loads and environmental factors. However, the environmental effect is not explicitly addressed in the ASME S-N curve which is based on air at room temperature. Therefore many studies have been performed to understand the environmental effects on fatigue behavior of materials used in nuclear power plants. As a part of efforts, we performed low cycle fatigue tests under various environmental conditions and analyzed the environmental effects on the fatigue life of SA508 Gr. 1a low alloy steel by comparing with higuchi's model. Test results show that the fatigue life depends on water temperature, dissolved oxygen and strain rate. But strain rate over 0.4%/s has little effect on the fatigue life. To find the cause of different fatigue life with ANL's and higuchi's model, another test performed with different heat numbered and heat treated materials of SA508 Gr. 1a. On a metallurgical point of view, the material with bainite microstructure shows much longer fatigue life than that with ferrite/pearlite microstructure. And the characteristics of crack propagation as different microstructure seem to be the main cause of different fatigue life.

• 사회복지연구
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• 제45권2호
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• pp.147-172
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• 2014

본 연구는 장애인들의 취업의사에 영향을 미치는 주요 요인으로서 가족의 긍정적 의사표현, 사회적 관계망, 그리고 장애정체감의 경로를 분석하는 데에 목적이 있다. 이를 위해 2010년 전국가정폭력 실태조사 자료 중 장애인관련 시설을 이용하는 성인장애인 453명을 대상으로 수집된 자료를 바탕으로 구조방정식 모형을 사용하여 주요 변수들의 인과관계를 검증하였다. 연구결과에 의하면, 가족원의 장애인에 대해 긍정적 의사표현의 빈도가 높을수록 장애인의 장애정체감과 취업의사가 증가되었다. 또한 사회적 관계의 빈도가 높을수록 장애인의 장애정체감이 상승되었으나 취업의사에는 직접적으로 영향을 미치지 않는 것으로 나타났다. 마지막으로 장애정체감은 취업의사를 결정하는 주요 요인으로서 파악되었다. 이상의 연구결과를 바탕으로 장애인의 낮은 취업의사로 인한 사회통합의 문제를 완화하고 예방하기 위한 개입 방안을 제언하였다.

• 한국경영과학회:학술대회논문집
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• 한국경영과학회/대한산업공학회 2005년도 춘계공동학술대회 발표논문
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• pp.975-982
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• 2005

The purpose of the Gage R&R study is to determine whether a measurement system is adequate for monitoring a process. If the measurement system variation is small relative to the process variation, then the measurement system is deemed 'adequate'. The sources of variation associated with the measurement system are compared using an analysis of variance (ANOVA) model, in general. A typical ANOVA model used in a standard Gage R&R study is the two-factor random effect model. Then, the ANOVA partitions the total variation into three categories: repeatability, reproducibility, part variation. However, if the process variation possesses the between group variation, within group variation, and within-part variation, these variations can cause the measurement system evaluation to provide misleading results. That is, in the standard Gage R&R study these variations affect the estimate of repeatability, reproducibility, or both. This paper presents a four-factor nested factorial ANOVA model which explicitly considers these variations for the Gage R&R study. The variance component estimates are derived by setting the EMS equations equal to the corresponding mean square from the ANOVA table and solving. And the proposed model is compared with the standard Gage R&R model.

• 산업공학
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• 제18권4호
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• pp.444-453
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• 2005

The purpose of the Gage R&R study is to determine whether a measurement system is adequate for monitoring a process. If the measurement system variation is small relative to the process variation, then the measurement system is deemed "adequate". The sources of variation associated with the measurement system are compared using an analysis of variance (ANOVA) model, in general. A typical ANOVA model used in a standard Gage R&R study is the two-factor random effect model. Then, the ANOVA partitions the total variation into three categories: repeatability, reproducibility, part variation. However, if the process variation possesses the between group variation, within group variation, and within part variation, these variations can cause the measurement system evaluation to provide misleading results. That is, in the standard Gage R&R study these variations affect the estimate of repeatability, reproducibility, or both. This paper presents a four-factor nested factorial ANOVA model which explicitly considers these variations for the Gage R&R study. The variance component estimators are derived by setting the EMS equations equal to the corresponding mean square from the ANOVA table and solving. And the proposed model is compared with the standard Gage R&R model.

• 한국IT서비스학회지
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• 제7권2호
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• pp.197-221
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• 2008

This study is to identify quality factors having influence upon mobile internet service performance theoretically, derive the research model and the hypotheses concerning the cause and effect relationship between these factors and service performance and then analyze them empirically. In order to enhance the model's explanation power, trust and cognitive engagement as interviewing variables are included in the model. The theoretical background of this study was brought from relevant literature in the areas of the theory of reasoned action(TRA). technology acceptance model(TAM), product selection model, cognitive absorption theory and etc. The research model and hypotheses were statistically investigated and analysed through convergent and discriminant validity test, reliability test, and path analyses by means of statistical packages SPSS(12.0) and LISREL(8.72). For these empirical analyses. data were collected through the field survey of 373 users who were willing to continuously use the mobile internet services. Based on the results of the analyses, theoretical and practical significance and future study direction were suggested. The results of this study will be helpful to giving a guideline to companies such as mobile telecom, mobile contents provider and mobile handset manufactures when they have to establish the mobile Internet service marketing strategies.

• 천문학회보
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• 제36권2호
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• pp.96.1-96.1
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• 2011

Halo coronal mass ejections (HCMEs) are major cause of the geomagnetic storms. To minimize the projection effect by coronagraph observations, we consider two CME cone models: an ice-cream cone model and an asymmetric cone model. These models allow us to determine three dimensional parameters of HCMEs such as radial speed, angular width, and the angle between sky plane and cone axis. In this study, we compare these parameters obtained from both models using 50 well-observed HCMEs from 2001 to 2002. Then we obtain the root mean square error (RMS error) between measured projection speeds and estimated ones for the models. As a result, we find that the radial speeds obtained from the models are well correlated with each other (R=0.89), and the correlation coefficient of angular width is 0.68. The correlation coefficient of the angle between sky plane and cone axis is 0.42, which is much smaller than what is expected. The reason may be due to the fact that the source locations of the asymmetric cone model are assumed to be near the center. The average RMS error of the asymmetric cone model (86.2km/s) is slightly smaller than that of the ice-cream cone model (88.6km/s).

• International Journal of Quality Innovation
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• 제4권2호
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• pp.101-122
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• 2003

With the development of the American Customer satisfaction index (ACSI), research on customer satisfaction measurement or evaluation methods have become significant in the last decade. Most of international customer satisfaction barometers or indices are evolved based on the cause and effect relationship model of ACSI. Of critical importance to validity of customer satisfaction indices is how to construct a measurement attribute or indicator model and provide an effective implementation method effectively. Quality Function Deployment (QFD) is a very useful tool for translating the customer voice into product design through quality engineering. In fact, this is a methodology for measuring and analyzing evaluation indicators by their relationship matrix. In this paper, we will make an effort to integrate the framework of QFD into the measurement problem of customer satisfaction, and also develop a new multi-phase QFD model for evaluation of Customer Satisfaction Index (CSI). From the houses of quality in this model, the evaluation indicators impacting on customer's global satisfaction are identified by means of their relationship matrix. Then the evaluation indicator hierarchy and its measurement method for the customer satisfaction index are presented graphically. Furthermore, survey data from the Chinese automobile maintenance sector and a relevant case study are utilized to show the implementation method of the QFD model used to measure and analyze of customer satisfaction.

• 한국방재학회 논문집
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• 제8권5호
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• pp.155-161
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• 2008

도시유역은 자연하천유역에 비해 다른 유형의 홍수피해를 보여주고 있다. 최근에 불투수면적의 증가로 홍수도달시간의 감소와 높은 첨두유량의 발생을 가져오면서 도시홍수피해의 원인이 되고있다. 본 연구에서는 XP-SWMM모형을 적용하여 침수심, 침수 면적을 시간대별로 침수해석을 수행하였으며, 침수해석시 건물의 영향을 고려하였다. XP-SWMM모형의 보정 및 검증을 위해 두 개의 강우사상(2005.06, 2005.07)을 적용하였고, 하천 외수위의 변하는 HEC-RAS모형을 통해 산정하였다. 모의결과 실제 관측된 침수면적(21.41ha)에 비해 산정된 침수구역의 면적은 23.45%로서 9.5% 과다하게 모의되었다. 또한 XP-SWMM모형의 DTM(DigitalTerrain Model)을 구축하여 주요 시간대별 건물의 영향에 따른 침수범위를 분석하였다.