• Environmental and Resource Economics Review
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• v.14 no.1
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• pp.75-100
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• 2005

This study attempts to empirically investigate the respondents' preference uncertainty involved in stating their willingness to pay (WTP). In the contingent valuation (CV) survey, we employed two approaches using two split samples. The respondents of one sample were given the opportunity to express intensity of preference through polychotomous choice (PC) WTP question. Those of the other sample were given a follow-up question of confidence measure (0~100%). By incorporating the two elicited degrees of preference uncertainty into examining the WTP responses, we take a comparison of the two approaches in terms of the goodness-of-fit of the examination and the efficiency of the mean WTP estimates. In comparing the DC model with the PC models, the DC model provides more efficient estimates. Moreover, the conventional DC model give some gains in terms of the goodness-of-fit and efficiency in comparing with the PC model most similar to this model. In this specific study, incorporating the preference uncertainty in DC model results greater estimates than conventional DC model without loss of goodness-of-fit and efficiency. This implies that the consideration of preference uncertainty on DC model could correct underestimating. We conclude that DC model provides a better estimate of WTP and preference uncertainty could be a critical information on the DC-CV estimation.

• Economic and Environmental Geology
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• v.41 no.6
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• pp.763-771
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• 2008

Uncertainties are pervasive in engineering geological problems. Therefore, the presence of uncertainties and their significance in analysis and design of slopes have been recognized. Since the uncertainties cannot be taken into account by the conventional deterministic approaches in slope stability analysis, the probabilistic analysis has been considered as the primary tool for representing uncertainties in mathematical models. However, some uncertainties are caused by incomplete information due to lack of information, and those uncertainties cannot be handled appropriately by the probabilistic approach. For those uncertainties, the theory of fuzzy sets is more appropriate. Therefore, in this study, fuzzy reliability analysis has been proposed in order to deal with the uncertainties which cannot be quantified in the probabilistic analysis due to the limited information. For the practical example, a slope is selected in this study and both the probabilistic analysis and the fuzzy reliability analysis have been carried out for planar failure. In the fuzzy reliability analysis, the dip angle and internal friction angle of discontinuity are considered as triangular fuzzy numbers since the random properties of the variables cannot be obtained completely under the conditions of limited information. In the study, the fuzzy reliability index and the probabilities of failure are evaluated from fuzzy arithmetic and compared to those from the probabilistic approach using Monte Carlo simulation and point estimate method. The analysis results show that the fuzzy reliability analysis is more appropriate for the condition that the uncertainties arise due to incomplete information.

• Journal of Navigation and Port Research
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• v.38 no.5
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• pp.493-501
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• 2014

An automated lifting vehicle(ALV) used in an automated container terminal is a type of unmanned vehicle that can self-lift a container as well as self-transport it to a destination. To operate a fleet of ALVs efficiently, one needs to be able to determine a minimum-time route to a given destination whenever an ALV is to start its transport job. To find a route free from any collision or deadlock, the occupation time of the ALV on each segment of the route should be carefully scheduled to avoid any such hazard. However, it is not easy because not only the travel times of ALVs are uncertain due to traffic condition but also the operation times of cranes en route are not predicted precisely. In this paper, we propose a routing method based on an ant colony optimization algorithm that takes into account these uncertainties. The result of simulation experiment shows that the proposed method can effectively find good routes under uncertainty.

• Proceedings of the Korean Information Science Society Conference
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• 2012.06b
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• pp.402-404
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• 2012

감시카메라의 성능이 향상됨에 따라 감시 카메라를 적용한 다양한 분야에 자동탐지 시스템의 적용 사례가 증가하고 있다. 하지만 동적인 상황이 빈번히 발생하는 실외환경에서의 감시카메라는 빛이나 날씨 등에 의해 불확실성을 일으킬 수 있다. 본 논문에서는 발생한 불확실성을 시계열로 보정하기 위한 방법으로 동적 베이지만 네트워크 기반의 시스템을 제안한다. 객체의 속도와 레이블, 방향 등을 시계열로 고려해 발생한 불확실한 상황에 대해 객체 검출을 보정하였다. 또한 실제 비디오 영상을 이용한 실험 및 평가를 수행하여 그 유용성을 입증하였다.

• Proceedings of the Korea Air Pollution Research Association Conference
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• 2002.04a
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• pp.141-142
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• 2002

대기환경 기준물질(criteria pollutants)은 NOx를 비롯하여 $O_3$, CO, SOx, PM 10, Pb 인데, 이러한 물질은 환경부에서 법적으로 규정한 대기오염공정 시험법에 따라서 분석된다. 대기오염공정 시험법이 충분한 과학적 근거를 갖는 분석법이 되기 위해서는 분석방법, 분석기기, 분석자 등에 의해 발생되는 불확실성을 최소화시키는 체계적인 관리가 필요하고, 분석기술의 발달수준, 측정분석의 요구수준, 새로운 국제 규격 통에 맞게 지속적으로 보완되어야 한다. (중략)

• Journal of Technology Innovation
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• v.20 no.3
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• pp.1-28
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• 2012

This study conducted a qualitative analysis on the Korea's nuclear energy sector in 2030 through scenario-based strategic foresight method. Specifically, the relationships between environmental influencing factors of the future nuclear energy sector was examined from a multi-dimensional perspective on the basis of STEEP analysis and network analysis. In addition, scenario planning method was used with key uncertainty factors (KUF) to create three predictable strategic scenarios including optimistic, business as usual, and pessimistic. Common strategies that need to be urgently pursued as well as the maximum risk avoidance strategies for each scenario were also presented. This study further identified energy pricing, global economic trend, competitiveness in nuclear technology, and marketing capability as key uncertainty factors in the future nuclear energy industry sector. In order to furnish effective export strategy in the future nuclear energy sector, it was also suggested that government policy should adopt following measures as top priorities: securing nuclear safety technology, educating nuclear engineers, securing nuclear resources such as uranium, increasing nuclear capability and so on. The implications and limitations of this study were then discussed based on research findings.

• Proceedings of the Korean Information Science Society Conference
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• 2004.10b
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• pp.88-90
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• 2004

대표적인 현재 및 미래 위치 색인인 TPR-Tree는 이동 객체의 위치 좌표와 속도 벡터 정보를 이용하여 시간에 대해 선형적으로 이동 객체의 현재 및 미래 위치를 예측한다. 그러나 이동 객체의 이동 방향 및 속도가 특정한 임계값을 벗어날 경우에는 서버로 새로운 위치 보고를 수행하기 때문에, 차량과 같이 이동 방향과 속도가 빈번하게 변하는 환경에 적용할 경우 서버로 잦은 보고를 필요로 하게 되어 통신비용을 크게 증가시키는 문제가 있다. 통신비용을 일정하게 유지하기 위한 방법으로 이동 객체의 보고를 일정한 시간 간격으로 수행하게 하는 방법이 있다. 그러나 일정한 시간 간격으로 이동 객체의 위치 보고가 수행되는 환경에서는 보고간격 사이에 속도와 방향이 변하게 되면 시간에 대해 선형적인 위치 예측 시에 오차가 발생할 수 있다. 본 논문에서는 일정한 시간 간격으로 이동 객체의 위치 보고가 수행되는 환경에서 보고 간격 사이에 이동객체의 이동 속도와 방향의 변화에 대한 불확실성을 반영하기 위하여 도로 네트워크를 이용한 이동 객체의 불확실 위치데이터의 질의 처리 기법을 제시한다.

• Economic and Environmental Geology
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• v.51 no.2
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• pp.203-211
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• 2018

Issues with past practice in seismic hazard analysis of nuclear power plant sites in Korea are addressed. Brief review on both deterministic and probabilistic methods in seismic hazard analysis is given, and most of the continuing discussion is focussed on the probabilistic seismic hazard analysis. Causes of uncertainty are traced on the basis of the cases that the assessment methodology was applied to the nuclear power plant sites. Considerations on the assessment include the role of experts, a representative seismic catalog, seismic source zonation, earthquake ground-motion relationship, and evaluation process. Factors increasing uncertainty in each item are analyzed and some feasible solutions are discussed.

• The Journal of the Convergence on Culture Technology
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• v.9 no.4
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• pp.375-381
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• 2023

In an increasingly hyperconnected battlefield, the reliance on battlefield networks and AI-based autonomous weapons systems creates uncertainty and raises ethical concerns. This article explores the responsibility gap in operating autonomous weapons systems, using Robert Sparrow's theory. By analyzing Sparrow's arguments, we propose overcoming the responsibility gap in lethal autonomous weapon systems (LAWS). Our objective is to establish a framework of responsibility that aligns with the evolving battlefield, promoting the development and use of responsible weapon systems.

• Journal of the Korean Society for Precision Engineering
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• v.16 no.2 s.95
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• pp.95-103
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• 1999

수중운동체가 수중에서 진행할 때 외부 파도에 의한 불확실한 부하 저항을 받으므로 이에 대응하는 핀(조타) 구동부의 제어 문제를 고려한다. 본 논문에서 제시하는 제어기는 본체로부터의 지정 각도를 부여 받으면 이에 부응하여 핀의 각도와 각속도를 이용하여 제어기의 알고리즘을 구축하여 지정된 경로를 추적하게 한다. 또한 핀의 각속도 정보의 이용이 부득이 어려운 상황에 대처하기 위하여 핀의 각도만을 이용한 출력제어기나 추정기를 설계하여 주위 환경의 불확실성을 극복할 수 있는 제어기를 제안한다. DC서보 모터로 구성괸 핀 구동부에 대해 실제 데이터를 사용하여 제안된 제어기의 성능을 시뮬레이션을 통하여 검증한다.