• 한국가스학회지
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• 제8권3호
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• pp.37-42
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• 2004

본 연구는 계절별 기후상태를 고려한 정성적 및 정량적 위험성 평가에 의해 최악의 시나리오와 가능성이 높은 시나리오를 설정하고, 비용-편익분석에 의해 시나리오별 안전관리비의 효율을 평가하였다. 그 결과, 최악의 시나리오는 비정상조업에서 유지보수 오류이었고, 가능성이 높은 시나리오는 HAZOP 구간 $\sharp$4에서 발생되는 가스 누출사고이었다. 또한 각 시나리오에서 전체 안전관리비에 대한 편익/비용과 효과적인 안전관리 항목을 평가할 수 있었다.

• 천문학회보
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• 제46권1호
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• pp.30.2-30.2
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• 2021

The extended Lyα nebulae (also known as Lyα blobs or LABs) observed at z=2-6 can provide clues to galaxy formation in the early universe. The connection of LABs with the overdensities of compact Lyα emitters suggests that they are associated with matter density peaks in the universe and thus likely to evolve into the present-day groups and clusters of galaxies. However, the mechanism powering the extended Lyα emission in LABs is remained controversial. The detection of polarization signals that follow the theoretically predicted trend is interpreted as strong evidence supporting that the LABs are caused primarily by the resonance scattering of Lyα originating from star-forming galaxies and AGNs. However, Trebitsch et al. (2016) claimed that the radial profile of polarization could be better explained by the scenario in which Lyα photons are produced in the cooling gas surrounding galaxies and then self-scattered by the gas, rather than by the scattering scenario of photons originating from the central galaxies. In this presentation, using LaRT, a state-of-art Lyα radiative transfer code, it is demonstrated that the observed polarization pattern can be reproduced even with the scattering scenario.

• Journal of Ecology and Environment
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• 제34권2호
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• pp.203-214
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• 2011

The objectives of this research were to predict land-use/land-cover change at the Sakaerat Environmental Research Station (SERS) and to analyze its consequences on the distribution for Black-crested Bulbul (Pycnonotus melanicterus), which is a popular species for bird-watching activity. The Dyna-CLUE model was used to determine land-use allocation between 2008 and 2020 under two scenarios. Trend scenario was a continuation of recent land-use change (2002-2008), while the integrated land-use management scenario aimed to protect 45% of study area under intact forest, rehabilitated forest and reforestation for renewable energy. The maximum entropy model (Maxent), Geographic Information System (GIS) and FRAGSTATS package were used to predict bird occurrence and assess landscape fragmentation indices, respectively. The results revealed that parts of secondary growth, agriculture areas and dry dipterocarp forest close to road networks would be converted to other land use classes, especially eucalyptus plantation. Distance to dry evergreen forest, distance to secondary growth and distance to road were important factors for Black-crested Bulbul distribution because this species prefers to inhabit ecotones between dense forest and open woodland. The predicted for occurrence of Black-crested Bulbul in 2008 covers an area of 3,802 ha and relatively reduces to 3,342 ha in 2020 for trend scenario and to 3,627 ha for integrated-land use management scenario. However, intact habitats would be severely fragmented, which can be noticed by total habitat area, largest patch index and total core area indices, especially under the trend scenario. These consequences are likely to diminish the recreation and education values of the SERS to the public.

• East Asian Economic Review
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• 제25권2호
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• pp.205-230
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• 2021

This study examines the impact of the number of coronavirus cases on regime-switching in stock return volatility. This study documents the empirical evidence that the COVID-19 cases had an asymmetric effect on the regime of stock return volatility. When the stock return is in the low volatility regime, the probability of switching to the high volatility regime in the next trading day increases as the number of cumulative cases increases. In contrast, in the high volatility regime, the effect of cumulative cases on the transition probability is not statistically significant. This study also documents the evidence that the government measures against the pandemic contribute to promoting the high volatility regime of the KOSPI during the pandemic. Besides, this study projects future stock prices through the Monte Carlo simulation based on the estimated parameters and the predicted number of the COVID-19 new cases. Under a scenario where the number of new cases rapidly increases, stock price indices in Korea are expected to be in a downward trend over the next three months. On the other hand, under the moderate scenario and the best scenario, the stock indices are likely to continue to rise.

• 한국기후변화학회지
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• 제9권2호
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• pp.133-142
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• 2018

Climate change will affect not only the crop productivity but also the pattern of rice disease epidemics in Korea. Impact assessments for the climate change are conducted using various climate change scenarios from many global climate models (GCM), such as a scenario from a best GCM or scenarios from multiple GCMs, or a combination of both. Here, we evaluated the feasibility of using a climate change scenario from the best GCM for the impact assessment on the potential epidemics of a rice leaf blast disease in Korea, in comparison to a multi?model ensemble (MME) scenario from multiple GCMs. For this, this study involves analyses of disease simulation using an epidemiological model, EPIRICE?LB, which was validated for Korean rice paddy fields. We then assessed likely changes in disease epidemics using the best GCM selected for individual agro?climatic zones and MME scenarios constructed by running 11 GCMs. As a result, the simulated incidence of leaf blast epidemics gradually decreased over the future periods both from the best GCM and MME. The results from this study emphasized that the best GCM selection approach resulted in comparable performance to the MME approach for the climate change impact assessment on rice leaf blast epidemic in Korea.

• 한국농공학회:학술대회논문집
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• 한국농공학회 2005년도 학술발표논문집
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• pp.502-508
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• 2005

In order to assess the environmental risk of pesticides, information is usually required on the likelihood of exposure of organisms to the constituents of pesticides, expressed as a predicted environmental concentrations (PECs) and the likely effects of the constituents of pesticides on aquatic and terrestrial organisms, expressed as a predicted no-effect concentrations (PNECs). In this paper, the pesticide fate model, RICEWQ alone and coupled with the pesticide movement model, RIVWQ was used to simulate the potential for predicting the environmental concentrations of pesticides in paddy fields and adjacent surface water systems. The RICEWQ model was successfully calibrated against field data in poinding depth for paddy field. For the assessment of importance for water and pesticide management conditions and field scales, the integrated RICEWQ-RIVWQ model was simulated by the scenario analysis. The results of this study can be used as a basic information for assessing the environmental risk of pesticides.

• 대한가정학회지
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• 제40권10호
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• pp.217-230
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• 2002

This article explored the perceptions of ‘family’and the factors related to respondents' definitions of a family. The data were collected from two types of people: one was 472 university students and high school students' parents who were asked whether or not each of 22 scenarios represented a‘family’, and the other was 40 young and middle-aged adults who were asked,“what is a family member?”. Results showed that (1) the overwhelming majority of respondents considered a married couple without a child(scenario #5) as a family and the least respondents agreed a divorced couple(scenario #18) as a family, (2) the majority perceived consanguinity, co-residence, parental status, and marital status to be important in the definition of a family, (3) middle-aged adults were more likely than young generation to agree that consanguinity and paternal relations were important in determining what a family member is.

• Asia pacific journal of information systems
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• 제9권1호
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• pp.115-142
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• 1999

Legacy applications are valuable assets that should be integrated into next generation business systems. To gain this advantage, progressive companies can reverse engineer the legacy business operations. This paper presents a form-driven object-oriented reverse engineering(FORE) methodology by the use of business forms to recover semantics of legacy applications. They retain the user-oriented contents of business and thus are easily understandable. Our form driven object-oriented reverse engineering methodology consists of five phases: form and usage analysis, form object slicing, object structure modeling, scenario design, and model integration. Knowledge about form structure and user interaction with legacy applications is used to capture the design semantics. An object model, which consists of an object structure model and scenario results from such form knowledge. The resulting object model is more likely to help reverse engineers understand and reuse legacy systems.

• 천문학회보
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• 제44권2호
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• pp.63.2-63.2
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• 2019

Recent submillimeter observations of ALMA reveal that many protoplanetary disks contain substructures like gaps or rings. The disk-planet interaction is believed to be the most likely gap formation scenario, and most previous numerical work attempted to constrain the planet mass using the density profiles of gas in the gaps. Since the dust and gas distributions likely differ from each other in protoplanetary disks, however, perturbed rotational velocities that directly probe the gas would give a more reliable estimate to the planet mass. In this work, we run two-dimensional hydrodynamic simulations to measure the amplitudes and widths of rotational velocity perturbations induced by planets with different mass. We present the parametric relations of the gap widths and depths as functions of the planet mass and disk properties. We also apply our relations to HD 163296 to infer the masses of embedded planets.

• 디지털융복합연구
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• 제14권8호
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• pp.203-209
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• 2016

스마트폰 이용 확대로 광고 매체시장이 큰 변화를 겪고 있다. 본 연구의 목적은 모바일광고의 부상이 가져 올 광고시장의 변화를 시나리오플래닝 기법으로 예측하는 것이다. 타켓팅 기술, 개인정보 규제, 광고회피 극복을 모바일광고 성장에 크게 영향을 주는 불확실 변수로 보고 전문가 인터뷰를 통해 5년 후 광고시장을 시나리오로 구성했다. 모바일광고가 유선인터넷 광고를 능가하는지 여부와 유무선 인터넷광고가 4대 매체 광고를 추가 잠식할지 여부 두 가지 경우를 $2{\times}2$ 매트리스로 조합하여, 모바일광고가 유선인터넷 광고는 물론 4대 매체를 추가로 잠식하는 경우, 유선인터넷 광고를 보조하는 수준에서만 성장하는 경우, 유선인터넷을 잠식하는 수준에서만 성장하는 경우, 마지막으로 유선인터넷 광고와 동반 퇴보하는 경우를 불확실 변수 전개에 따라 기술했다. 전문가들은 모바일이 광고 매체시장을 평정하는 상황을 가장 유력하게 보고 있다. 하지만 타켓팅 기술, 광고회피 극복, 개인정보 활용 범위 등 불확실 변수가 어떻게 진행되느냐에 따라 충분히 다른 시나리오도 가능하다. 앞으로 기술 변수를 사회경제적인 변수와 결합하고 기술을 좀 더 세분화시켜야 하는 과제를 안고 있다.