• Ocean and Polar Research
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• 제23권3호
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• pp.223-242
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• 2001

This paper presents the depth-mean monthly variation in the circulation of the Yellow Sea and the East China Sea computed using a robust diagnostic model. The mixed three-dimensional finite-difference Galerkin function model developed by Lee et at. (2000, 2001) has been extended to take into account baroclinic effects and then used to calculate the depth-mean flow fields as part of the results. In addition to M2 tide and oceanic flows previously considered, the model has been driven by the monthly mean wind stresses from Na and Seo (1998), the density gradient calculated based on by GDEM data set released by US Navy. Model results are very encouraging in that many of observed features including Jeju Cyclonic Gyre and frontal eddies along the shelfside of the Kuroshio main stream and west of Kyushu, are satisfactorily reproduced and are expected to be of value in interpreting observations in various oceanograhic disciplines.

• 한국안전학회지
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• 제35권1호
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• pp.70-78
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• 2020

Nitrox diving was introduced by the NOAA (National Oceanic and Atmospheric Administration) to increase the oxygen content and lower the nitrogen content in respiratory gases. The commercial diving sector specializing in underwater operations has recently introduced regulations on the use of Nitrox. Because the respiratory gas for Nitrox diving has a lower nitrogen content than the normal air, the amount of nitrogen dissolved in the body is small, which not only significantly reduces the decompression time compared to air diving, but also reduces the chance of exposure to decompression sickness. In this study, we applied the VPM (Varying Permeability Model) algorithm to virtual diving with air and Nitrox as a respiratory gas, respectively, to study the optimal Nitrox diving for the safety at the underwater works. The results showed that Nitrox diving had a longer NDL (No-Decompression Limit), a much shorter depression time. In other words, Nitrox diving in underwater works is safer from decompression sickness than commonly used air diving.

• 한국수자원학회:학술대회논문집
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• 한국수자원학회 2005년도 학술발표회 논문집
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• pp.138-142
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• 2005

The change of precipitation and temperature due to the global. warming eventually caused the variation of water availability in terms of potential evapotranspiration, soil moisture, and runoff. In this reason national long-term water resource planning should be considered the effect of climate change. Study of AOGCM-based scenario to proposed the plausible future states of the climate system has become increasingly important for hydrological impact assessment. Future climate changes over East Asia are projected from the coupled atmosphere-ocean general circulation model (AOGCM) simulations based on Intergovernmental Panel on Climate Change (IPCC) Special Report on Emissions Scenarios (SRES) A2 and B2 scenarios using multi-model ensembles (MMEs) method (Min et al. 2004). MME method is used to reduce the uncertainty of individual models. However, the uncertainty increases are larger over the small area than the large area. It is demonstrated that the temperature increases is larger over continental area than oceanic area in the 21st century.

• 한국환경과학회지
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• 제20권6호
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• pp.679-686
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• 2011

The characteristics of circulation in the coastal area of Jeju Harbor in Korea was examined using the Princeton Ocean Model(POM) with a sigma coordinate system. The result of numerical analysis well corresponded to the observed current data. The velocity at offshore was stronger compared to coastal area during the both period of in maximum flood and maximum ebb of spring tide. According to mean wind velocity, the tidal velocity at the shallow area of Jocheon was slightly increasing during maximum ebb. The effect of wind on the circulation was stronger in shallow area and showed rapid change with depth.

• 한국정보처리학회:학술대회논문집
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• 한국정보처리학회 2006년도 추계학술발표대회
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• pp.183-186
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• 2006

NPC(Non playable Character)모델은 온라인 게임뿐만 아니라 가상공간 시스템 구축 시 빠질 수 없는 중요한 요소이다. 현재 가장 널리 사용되는 인공지능 처리방식의 하나인 FSM(Finite State Machine)은 NPC의 행동양식을 표현하기 위해 유한한 개수의 상태를 이용하는 알고리즘이다. 인공지능이 적용된 NPC 모델 설계시 정확한 명세는 구현 단계에서 발생되는 자원의 손실을 막아주고 요구명세에 따른 검증을 가능하게 한다. 본 논문에서는 해저가상공간 구축 시 발생되는 어류 객체의 행동패턴을 분석하여 속성을 정의하였으며, 환경변화에 따른 행동 특성의 상호관계를 설정하여 정형화하였다. 정의된 속성을 가진 NPC 모델을 FSM 알고리즘을 적용해 설계하고 구현한다. 설계된 NPC모델은 CTL기반의 모델체커인 SMV(Symbolic Model Verification)를 통해 검증함으로써 설계에 대한 타상성을 입증하였다.

• 한국환경과학회지
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• 제5권4호
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• pp.429-440
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• 1996

A global carbon cycle model (GCCM), that incorporates interaction among the terrestrial biosphere, ocean, and atmosphere, was developed to study the carbon cycling aid global carbon budget, especially due to anthropogenic $CO_2$ emission. The model that is based on C, 13C and 14C mass balance, was calibrated with the observed $CO_2$ concentration, $\delta$13C and $\Delta$14C in the atmosphere, Δ14C in the soil, and $\Delta$14C in the ocean. Also, GCCM was constrained by the literature values of oceanic carbon uptake and CO, emissions from deforestation. Inputs (forcing functions in the model) were the C, 13C and 14C as $CO_2$ emissions from fossil fuel use, and 14C injection into the stratosphere by bomb-tests. The simulated annual carbon budget of 1980s due to anthropoRenic $CO_2$ shows that the global sources were 5.43 Gt-C/yr from fossil fuel use and 0.91 Gt-C/yr from deforestation, and the sinks were 3.29 Gt-C/yr in the atmosphere, 0.90 Gt-C/yr in the terrestrial biosphere and 2.15 Gt-C/yr in the ocean. The terrestrial biosphere is currently at zero net exchange with the atmosphere, but carbon is lost cia organic carbon runoff to the ocean. The model could be utilized for a variety of studies in $CO_2$ policy and management, climate modeling, $CO_2$ impacts, and crop models.

• 한국수자원학회논문집
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• 제31권5호
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• pp.613-620
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• 1998

샌프란시스코 해양방류의 근영역거동에 대한 현장 및 실험연구는 유량조건과 해양조건을 만족하는 것으로 다공확산관에 의한 해양방류의 전형적인 유형이라 할 수 있다. 특히 실험자료들은 현장시험을 모의한 밀도층을 갖는 견인수조로부터 얻어진 것이다. 이들 자료를 이용한 폐수영역거동의 모형연구는 최소희석률, 회종희석높이 및 희석두께를 수리 및 수학적 모형인 UM모형, UDKHDEN모형, RSB모형과 CORMIX 모형을 이용한 예측치와 실측치를 비교 분석하였다. 수리모형연구는 현장에서 관측된 주요현상들을 재현할 수 있었다. 또한 현장시범이나 수학적모형으로부터 얻을 수 없는 다공확산관의 혼합기능을 관찰 할 수 있다.

• 한국지구과학회지
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• 제42권4호
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• pp.390-400
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• 2021

Ocean biogeochemistry plays a crucial role in sustaining the marine ecosystem and global carbon cycle. To investigate the oceanic biogeochemical responses to iron parameters in the tropical Pacific, we conducted sensitivity experiments using the Nucleus for European Modelling of the Ocean-Tracers of Ocean Phytoplankton with Allometric Zooplankton (NEMO-TOPAZ) model. Compared to observations, the NEMO-TOPAZ model overestimated the concentrations of chlorophyll and dissolved iron (DFe). The sensitivity tests showed that with increasing (+50%) iron scavenging rates, chlorophyll concentrations in the tropical Pacific were reduced by approximately 16%. The bias in DFe also decreased by approximately 7%; however, the sea surface temperature was not affected. As such, these results can facilitate the development of the model tuning strategy to improve ocean biogeochemical performance using the NEMO-TOPAZ model.

• 대한원격탐사학회지
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• 제14권2호
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• pp.117-128
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• 1998

본 연구는 Topeux/Poseidon 위성의 첫 운행인 1992년 9월~1994년 8월(2년간, 73 사이클) 동안에 남인도양의 암스테르담-코호제트-케르겔른 지역(35$^{\circ}$-55$^{\circ}$S, 55$^{\circ}$-80$^{\circ}$E)에서의 환경학적 보정인자들의 특성을 조사하기 위하여 수행되었다. 환경 보정인자들의 특성이 지역에 따라 어떻게 다른가를 알아 보기 위하여, 상승 지상트랙 103이 지나는 암스테르담-케르겔른 대지지역과 하강 지상트랙 170이 지나는 코호제트 분지지역으로 구분하여 비교하였다. 전리권, 건조 및 습윤 대류권, 전자기적 편차, 탄성조, 하중조들과 같은 보정인자들의 변화폭은 일반적으로 수 cm 이하로 나타났으나, 해양조 및 해면기압의 변화폭은 각각 30~35cm, 15~30cm로서 다른 보정인자들의 변화폭 보다 상당히 높게 나타났다. 남인도 양의 해수면 변화는 주로 해양조석에 기인하며 그 기여도는 80~90%에 이른다. 그리고 두 번째의 기여 인자는 해면기압으로 무시할 수 없을 정도로 중요한 환경 보정인자임을 알 수 있었다

• 대기
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• 제27권3호
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• pp.359-370
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• 2017

In this study, the oceanic Total Precipitable Water (TPW) retrieval algorithm at 16 km altitude of High Altitude Long Endurance Unmanned Aerial Vehicle (HALE UAV) is described. Empirical equation based on Wentz method (1995) that uses the 18.7 and 22.235 GHz channels is developed using the simulated brightness temperature and SeeBor training dataset. To do radiative simulation, Satellite Data Simulator Unit (SDSU) Radiative Transfer Model (RTM) is used. The data of 60% (523) and 40% (349) in the SeeBor training dataset are used to develop and validate the TPW retrieval algorithm, respectively. The range of coefficients for the TPW retrieval at the altitude of 3~18 km with 3 km interval were 153.69~199.87 (${\alpha}$), 54.330~58.468 (${\beta}$), and 84.519~93.484 (${\gamma}$). The bias and RMSE at each altitude were found to be about $-0.81kg\;m^{-2}$ and $2.17kg\;m^{-2}$, respectively. Correlation coefficients were more than 0.9. Radiosonde observation has been generally operated over land. To validate the accuracy of the oceanic TPW retrieval algorithm, observation data from the Korea Meteorological Administration (KMA) Gisang 1 research vessel about six clear sky cases representing spring, autumn, and summer season is used. Difference between retrieved and observed TPW at 16 km altitude were in the range of $0.53{\sim}1.87kg\;m^{-2}$, which is reasonable for most applications. Difference in TPW between retrieval and observation at each altitude (3~15 km) is also presented. Differences of TPW at altitudes more than 6 km were $0.3{\sim}1.9kg\;m^{-2}$. Retrieved TPW at 3 km altitude was smaller than upper level with a difference of $-0.25{\sim}0.75kg\;m^{-2}$ compared to the observed TPW.