• 인지과학
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• 제25권2호
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• pp.135-157
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• 2014

본 연구는 6개월 및 12개월 영아들이 행위자(agent)의 사회적인 선호를 추론할 때, 이전에 있었던 사회적 상호작용 내의 행동 의도 정보를 고려할 수 있는지 살펴보았다. 친숙화 시행에서 12개월(실험 1), 6개월(실험 2) 영아들은 한 도형(세모 또는 네모)이 동그라미를 밀어 올려서 동그라미가 언덕을 오를 수 있도록 돕는 장면과 다른 도형이 동그라미를 아래쪽으로 밀어서 언덕을 오를 수 없도록 방해하는 장면을 보았다. 이 때, 도움 행동과 방해 행동의 의도만 제시하고, 행동의 결과, 즉 목표 달성의 성공 또는 실패는 명확하게 보여주지 않았다. 검사 시행에서 영아들은 동그라미가 도움자 도형에게 접근하는 장면(도움자 접근 조건)을 보거나 방해자 도형에게 접근하는 장면(방해자 접근 조건)을 보았다. 그 결과, 두 연령 집단 모두 방해자 접근 조건일 때보다 도움자 접근 조건일 때, 검사 시행을 유의미하게 더 오래 보았다. 이는 6-12개월 영아가 행위자의 의도를 고려해서 도움자와 방해자를 구별할 수 있으며 이러한 정보를 바탕으로 행위자의 사회적 선호를 추론할 수 있음을 보여준다. 본 연구 결과는 영아들이 돕기와 같은 도덕 관련 행동의 의도를 고려할 수 있고, 이를 통해 행위자의 사회적 선호를 추론할 수 있는 능력이 생후 1년 이내에 존재할 수 있음을 보여준다.

• 자원환경지질
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• 제16권1호
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• pp.51-61
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• 1983

By using local earthquake data, the Korean crust model and travel-time tables were determined. The upper crustal earthquakes (Hongsung event and Ssanggyesa event) were considered as auxiliary information, and the lower crustal earthquakes (Uljin event and Pohang event) played an important role in determining model parameters. The possible existence of Low Velocity Layer (LVL) in the upper mantle was suggested by discrepancy in the arrival times of Sariwon earthquake which occurred below Moho discontinuity. Computer program for the determination of the model parameters was developed in order to screened out the optimum parameters by comparing the travel times of observed data with theoretical ones. We found that the discontinuities of Conrad, Moho, and upper and lower boundaries of LVL have their depth of 15, 32, 55 and 75 Km, respectively. The velocities of P-and S-wave in the layers between those discontinities were found to be (1) 5.98, 3.40 Km/sec (2) 6.38, 3.79 Km/sec (3) 7.95, 4.58 Km/sec (4) unknown (5) 8.73, 5.05 Km/sec, respectively from the top layer. Travel-time tables were also computed for the inter-local earthquakes which have their direct wave paths above the LVL.

• 대기
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• 제25권4호
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• pp.577-589
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• 2015

An unusual long-period and heavy snowfall occurred in the Yeongdong region from 6 to 14 February 2014. This event produced snowfall total of 194.8 cm and the recordbreaking 9-day snowfall duration in the 103-year local record at Gangneung. In this study, satellite-derived cloud-top brightness temperatures from the infrared channel in the atmospheric window ($10{\mu}m{\sim}11{\mu}m$) are examined to find out the characteristics of clouds related with this heavy snowfall event. The analysis results reveal that a majority of precipitation is related with the low-level stratiform clouds whose cloud-top brightness temperatures are distributed from -15 to $-20^{\circ}C$ and their standard deviations over the analysis domain (${\sim}1,000km^2$, 37 satellite pixels) are less than $2^{\circ}C$. It is also found that in the above temperature range precipitation intensity tends to increase with colder temperature. When the temperatures are warmer than $-15^{\circ}C$, there is no precipitation or light precipitation. Furthermore this relation is confirmed from the examination of some other heavy snowfall events and light precipitation events which are related with the low-level stratiform clouds. This precipitation-brightness temperature relation may be explained by the combined effect of ice crystal growth processes: the maximum in dendritic ice-crystal growth occurs at about $-15^{\circ}C$ and the activation of ice nuclei begins below temperatures from approximately -7 to $-16^{\circ}C$, depending on the composition of the ice nuclei.

• 한국콘텐츠학회논문지
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• 제12권9호
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• pp.9-15
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• 2012

기존의 이벤트 문장 추출에 관한 연구는 학습단계에서 3W 자질을 학습하지 않고, 추출단계에서 3W 자질의 존재여부에 따른 규칙만을 적용하여 이벤트 문장을 추출하였다. 본 논문에서는 온라인 동향 분석을 위해 학습단계에서 3W 자질을 추출하고 가중치를 계산하고, 추출단계에서 3W 자질을 반영하는 문장 가중치 기반 이벤트 문장 추출 방안을 제시한다. 실험결과, 자질필터링은 $TF{\times}IDF$ 가중치 기법을 사용한 상위 30% 자질만을 사용하는 것이 가장 우수한 결과를 보였다. 공공이슈 분야인 부동산 도메인에서 문장 가중치 기반 방법은 3W 자질 중 who와 when 자질이 가장 영향을 많이 미치는 것으로 나타났다. 아울러 다른 기계학습 방법과의 비교하여 공공이슈 분야인 부동산 도메인에서 문장 가중치 기반 이벤트 문장 추출 방법이 가장 좋은 성능을 보였다.

• 한국수소및신에너지학회논문집
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• 제17권3호
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• pp.272-278
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• 2006

This study is quantitatively assessing of safety about dispenser of hydrogen station because it is hydrogen energy to efficient safety use. The large leakage of hydrogen gas is the most important accident among others occurrence possibility in hydrogen station. It had written FT by top event and calculated unavailability, m-cutsets, leakage frequency, etc with FTA after each base event collect reliability data by reliability data handbook, THERP-HRA and estimation of the engineering.

• 에너지공학
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• 제26권4호
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• pp.23-28
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• 2017

Hazard evaluation and FTA are performed as the first and the second step of QRA for a LNG storage tank. Hazards are identified using HAZOP. Each segment of the system is examined, and we list all possible deviations from normal operating conditions and how they might occur. The consequences on the process are assessed, and the means available to detect and correct the deviations are reviewed. The FTA is carried out to analyse the hazards identified from the HAZOP study. A top event is selected to be release of LNG. Then all combinations of individual failures that can lead to the hazardous event are shown in the logical format of the fault tree system.

• 한국정보시스템학회지:정보시스템연구
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• 제17권3호
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• pp.25-37
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• 2008

In a fault tree analysis, an uncertainty importance measure is often used to assess how much uncertainty of the top event probability (Q) is attributable to the uncertainty of a basic event probability ($q_i$), and thus, to identify those basic events whose uncertainties need to be reduced to effectively reduce the uncertainty of Q. For evaluating the measures suggested by many authors which assess a percentage change in the variance V of Q with respect to unit percentage change in the variance $v_i$ of $q_i$, V and ${\partial}V/{\partial}v_i$ need to be estimated analytically or by Monte Carlo simulation. However, it is very complicated to analytically compute V and ${\partial}V/{\partial}v_i$ for large-sized fault trees, and difficult to estimate them in a robust manner by Monte Carlo simulation. In this paper, we propose a method for evaluating the measure using discretization technique and Monte Carlo simulation. The proposed method provides a stable uncertainty importance of each basic event.

• Nuclear Engineering and Technology
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• 제52권10호
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• pp.2238-2249
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• 2020

In a seismic PSA, dependency among seismic failures of components has not been explicitly modeled in the fault tree or event tree. This dependency is separately identified and assigned with numbers that range from zero to unity that reflect the level of the mutual correlation among seismic failures. Because of complexity and difficulty in calculating combination probabilities of correlated seismic failures in complex seismic event tree and fault tree, there has been a great need of development to explicitly model seismic correlation in terms of seismic common cause failures (CCFs). If seismic correlations are converted into seismic CCFs, it is possible to calculate an accurate value of a top event probability or frequency of a complex seismic fault tree by using the same procedure as for internal, fire, and flooding PSA. This study first proposes a methodology to explicitly model seismic dependency by converting correlated seismic failures into seismic CCFs. As a result, this methodology will allow systems analysts to quantify seismic risk as what they have done with the CCF method in internal, fire, and flooding PSA.

• 대한인간공학회지
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• 제19권3호
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• pp.61-75
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• 2000

To enhance web site's usability, it has been suggested that the depth of tree structured menus should be minimized. In this research, experimental results are reported to quantitatively compare the methods currently used for reducing the depth of menus in web sites. 25 popular web sites were selected and their menu types were categorized into four types: top menu, drop-down menu, boolean menu, and table of contents. The four types of menu were then sub-categorized into 15 different types according to their sub-menu type, existence of menu colors, and the event occurring after mouse activation. Performance tests and subjective evaluation were carried out. The results showed that there were no significant differences in terms of response time among the 15 menu types, while table of contents and drop-down in which the first and second level of menus were visible induced the least number of errors. In the subjective test, the top-menu structure with colors and presentation of its sub-menu without clicking mouse were preferred.

• 산업경영시스템학회지
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• 제13권21호
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• pp.43-50
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• 1990

Fault tree analysis(FTA) is available to the engineer for determining reliability of complex industrial safety system. Therefore quantitative aspects of FTA greatly multiply its power this paper proceeds of presenting the methodology of FTA, including an approach to constructing in fault tree. A working guide to the use of FTA for the purpose of cost/benefit determination in industrial safety system is given. Finally, an analytic method for uncertainty analysis of the top event of a complex system is described.