• Korean Journal of Remote Sensing
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• v.39 no.3
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• pp.355-361
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• 2023

Temperature of the Earth's surface is a crucial physical variable in understanding weather and atmospheric dynamics and in coping with extreme heat events that have a great impact on living organismsincluding humans. Thermalsensors on satellites have been a useful meansfor acquiring surface temperature information for wide areas on the globe, and thus characterization of its estimation uncertainty is of central importance for the utilization of the data. Among various factors that affect the estimation, the uncertainty caused by the algorithm itself has not been tested for the atmospheric environment of Korean vicinity. Thisstudy derivesthe uncertainty of the single-channel algorithm under the local atmospheric and oceanic conditions by using reanalysis data and buoy temperature data collected around Korea. Atmospheric profiles were retrieved from two types of reanalysis data, the fifth generation of European Centre for Medium-Range Weather Forecasts reanalysis of the global climate and weather (ERA5) and Modern-Era Retrospective analysis for Research and Applications-2 (MERRA-2) to investigate the effect of reanalysis data. MODerate resolution atmospheric TRANsmission (MODTRAN) was used as a radiative transfer code for simulating top of atmosphere radiance and the atmospheric correction for the temperature estimation. Water temperatures used for MODTRAN simulations and uncertainty estimation for the single-channel algorithm were obtained from marine weather buoyslocated in seas around the Korean Peninsula. Experiment results showed that the uncertainty of the algorithm varies by the water vapor contents in the atmosphere and is around 0.35K in the driest atmosphere and 0.46K in overall, regardless of the reanalysis data type. The uncertainty increased roughly in a linear manner as total precipitable water increased.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.28 no.5B
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• pp.495-504
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• 2008

Evapotranspiration (ET) is an important state variable while simulating daily streamflow in hydrological models. In the estimation of ET, for example, when using FAO Penman Monteith equation, the LAI (Leaf Area Index) value reflecting the conditions of vegetation generally affects considerably. Recently in evaluating the vegetation condition as a fixed quantity, the remotely sensed LAI from MODIS satellite data is available, and the time series values of spatial LAI coupled with land use classes are utilized for ET evaluation. Four years (2001-2004) of MODIS LAI was prepared for the evaluation of Penman Monteith ET in the continuous hydrological model, SLURP (Semi-distributed Land Use-based Runoff Processes). The model was applied for simulating the dam inflow of Chungju watershed ($6661.3km^2$) located in the upstream of Han river basin. For four years (2001-2004) dam inflow data and meteorological data, the model was calibrated and verified using MODIS LAI data. The average Nash-Sutcliffe model efficiency was 0.66. The 4 years watershed average Penman Monteith ETs of deciduous, coniferous, and mixed forest were 639.1, 422.4, and 631.6 mm for average MODIS LAI values of 3.64, 3.50, and 3.63 respectively.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.30 no.2B
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• pp.219-231
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• 2010

The Reference Evapotranspiration Calculator Software (REF-ET) supports computational guidelines for the reference evapotranspiration using seventeen FAO Penman-Monteith (PM) equations simultaneously such as the ASCE and FAO standardized forms. The REF-ET can conveniently consider missing data predictions and regional site characterizations, when reference ET is computed on monthly, daily, and hourly time steps. The applicability of the REF-ET was estimated to simulate the reference ET using hourly weather data from Seoul weather station for 29 years. The result found that the FAO24-Rd and 1957-Makk equations closely concerned with solar radiation parameter which were the most highly correlated to reference ET computed by pan coefficient. In addition, the 1957-Makk equation was identified as the most correct computational method for reference ET by analysis of bias and root mean square error. The 1957-Makk equation could predict the reference ET within the error of less than 1.06 mm/day, though all the other equations tended toward overestimation of predicting the reference ET in comparison with refecence ET of pan. The results of this study suggest that the REF-ET will be applicable to support reference ET estimation for a variety of field condition and time-scale.

• Journal of the Korean Geographical Society
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• v.50 no.3
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• pp.255-276
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• 2015

This paper presents a multi-agent system model of land-use and cover changes, which is developed and applied to the Gariwang-san and its vicinity, located in Pyeongchang and Jeongseon-gun, Gangwon province, Korea. The Land Use Dynamics Simulator (LUDAS) framework of this study is well suited for representing the spatial heterogeneity and dynamic interactions between human and natural environment, and capturing the impacts of forest-opening policy interventions to future socio-economic and natural environment changes. The model consists of four components: (1) a system of human population, (2) a system of landscape environment, (3) decision-making procedures integrating human(or household), environmental and policy information into forest land-use decisions, and (4) a set of policy scenarios that are related to the forest-opening. The results of model simulation by different combination of various forest management scenarios are assessed by the levels of household income, ecosystem service value and income inequality in the study region. As a result, the optimal scenario of forest-opening policies in the study region is to open the forest to local residential community for the purpose of recreation, considering the distinctive topographical feature. The model developed in this research is expected to contribute to a decision support system for sustainable forest management and various land-use policies in Korea.

• Korean Journal of Environment and Ecology
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• v.38 no.2
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• pp.204-216
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• 2024

Understanding the trade-off effect in ecosystem services and measuring the interrelationships between services are crucial for managing limited environmental resources. Accordingly, in this study, we identified the dominant trends and increases and decreases in ecosystem services derived from changes in land cover over about 30 years and tracked changes in the relationships between ecosystem services that occurred over time. Through it, we determined the relationship between land cover changes and ecosystem service changes, as well as the distinct characteristics of service changes in different areas. The research primarily utilized the InVEST model, an ecosystem service assessment model. After standardizing the evaluation results between 0 and 1, it went through principal component analysis, a dimensionality reduction technique, to observe the time-series changes and understand the relationships between the services. According to the research results, the area of urbanized regions dramatically increased between 1989 and 2019, while forests showed a significant increase between 2009 and 2019. Between 1989 and 2019, the national ecosystem service supply witnessed a 13.9% decrease in water supply, a 10.5% decrease in nitrogen retention, a 2.6% increase in phosphorus retention, a 0.9% decrease in carbon storage, a 1.2% increase in air purification, and a 3.4% decrease in habitat quality. Over the past 30 years, South Korea experienced an increase in urbanized areas, a decrease in agricultural land, and an increase in forests, resulting in a trade-off effect between phosphorus retention and habitat quality. This study concluded that South Korea's environment management policies contribute to improving ecosystem quality, which has declined due to urbanization, and maximizing ecosystem services. These findings can help policymakers establish and implement forestry policies focusing on sustainable environmental conservation and ecosystem service provision.

• Journal of Nutrition and Health
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• v.9 no.4
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• pp.4-8
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• 1976

영양지도원(營養指導員)은 자신(自身)이 알고 있는 기술(技術)을 다른 사람에게 전달(傳達)하여 그 사람으로 하여금 지도원(指導員)이 원하는 방향(方向)으로 행동(行動)을 하도록 해야 한다. 따라서 다른 사람을 지도(指導)하려면은 우선 지도원 자신(指導員自身)의 우수한 자질(資質)"이 필요(必要) 하며 이를 위(爲)하여 기술자(技術者)로서의 연마(硏磨)와 겸(兼)하여 인간(人間)의 지도자(指導者)로서의 수양(修養)을 쌓아야 한다. 그리하여 영양개선(營養改善) 의 선도적(先導的) 점화자(點火者)로 "뒤에서 계속 미는" 지원자(支援者)로서의 역할(役割)을 수행(遂行)하여야 한다. (1) 현직능별(現職能別) 영양지도원(營養指導員)의 범위(範圍)를 보건소(保健所)의 보건지도원(保健指導員), 농촌지도소(農村指導所)의 생활지도요원(生活指導要員), 군면(郡面)의 행정지도요원(行政指導要員), 농협(農協)의 부여지도요원(婦女指導要員), 의료계(醫療界)의 의사(醫師), 간호원(看護員), 조산원(助産員), 학교(學校) 교육기관(敎育機關)의 교사(敎師), 영양사(營養士), 영리회사(營利會社)의 사원(社員) 등을 들 수 있다. (2) 지도대상(指導對象)과 그 장소(場所)는 공장(工場), 학교(學校), 훈련장(訓練場), 병원(病院), 복지시설(福祉施設)과 공동취사(共同炊事) 재해시등(災害時等)의 집단급식장(集團給食場)과 이를 이용(利用)하는 對象者(대상자) 도시(都市) 농촌(農村)의 일반가정(一般家庭)의 주민(住民), 그리고 교실(敎室)에서 학교교과목(學校敎科目)을 통(通)한 학생(學生)의 학습(學習) 새마을운동(運動) 공보시설(公報施設)을 통(通)하여 대중(大衆)에게 "지도(指導)를 지도원(指導員)이" 전개(展開)할 수 있다. (3) 지도방법(指導方法)은 일반적(一般的) 학교교육과정(學校敎育過程)의 교육방법(敎育方法)을 적용(適用)하되 교외교육(校外敎育)이라는 점(點)을 잊어서는 안된다. 현실적(現實的)으로 이론(理論)과 경험(經驗)을 병행활용(倂行活用)하며 영양학(營養學)의 연구결과(硏究結果)가 반드시 또 는 곧 가정생활(家庭生活) 개인생활(個人生活)에 적응(適應)되는 것이 아니며, 행동화(行動化)되지 않는 지식(知識)과 기술(技術)은 무용(無用)하게 되므로 "다고 말 할 수 있다. 따라서 영양개선(營養改善)을 지도(指導)하는 지도원(指導員)은 받아들이는 가정(家庭)이나 개인(個人)의 입장(立場)에서 여러 가지 여건을 파악 최대공약수(最大公約數)의 가능치(可能値)를 알아내서 지도(指導)해야 된다. (4) 영양지도(營養指導)는 기술(技術)이 ,포함(包含)되어 있기 때문에 기술(技術)의 전달과정(傳達過程)을 분석(分析)해야 되고 (5) 지도원(指導員) 자신의 무장(武裝)을 위(爲)하여 자신(自身)의 기술지도(技術指導) 방법(方法), 인간지도자(人間指導者)로서의 능력향상(能力向上)을 독서(讀書), 교육(敎育), 훈련(訓練) 을 통(通)하여 배워 기술자(技術者)로서 인간지도자(人間指導者)로서 전달자(傳達者)로 서의 교양(敎養)을 가져야 한다. (6) 지도원(指導員)의 활동성과(活動成果)는 지도원(指導員) 자신의 열의(熱意)와 받아들이는 사람의 열의(熱意)에 의(依)하여 좌우(左右)된다. 즉(卽) 지도원(指導員)의 열의(熱意)${\times}$피지도자(被指導者)의 열의(熱意)=지도성과(指導成果) $[L{\times}P=f(L{\cdot}P)]$로 나타난다. 결론적(結論的)으로 지도원(指導員)은 영양개선(營養改善)의 전문적(專門的) 각 요소(各要素)를 깊이 알고 이것을 다시 종합(綜合)하고 체계화(體系化)할 줄 알며 직능별(職能別) 각 지도원(各指導員)과의 상호(相互) 협조(協助)로 서로 보완(補完)하고 새마을 운동(運動)과 그 직장(職場) 또는 환경(環境)여건에 결부(結付)되고 현실적(現實的)으로 행동화(行動化)할 수 있는 단계적(的) 장단기계획(長短期計劃)과 평가방법(評價方法)을 숙지(熟知)하여 또 지도방법(指導方法)에 필요(必要)한 교재(敎材)를 충실(充實)히 준비하여 자신(自身)의 실력(實力)을 충분(充分)히 발휘할 수 있도록 하여 자기 열의(熱意)를 다하고" 영양개선(營養改善)의 선도적(先導的) 점화자(點火者)로서 "계속 뒤에서 미는" 지원자(支援者)로서 사명(使命)을 다할 때 그 역할(役割)을 다하는 것이다.

• Journal of the Korean Institute of Landscape Architecture
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• v.41 no.3
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• pp.22-30
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• 2013

This study aims to measure the thermal comfort effects of urban street trees. As the usual dry bulb air temperature does not indicate properly how the average pedestrian feels the heat of a typical summer day under the strong sunshine, we adopted the Wet Bulb Globe Temperature(WBGT). WBGT involves black globe temperature to measure the direct radiation of sun beams on our bodies, for example our heads. We measured temperatures on very sunny and hot summer days, August 3, 4, and 7, 2012, on the urban streets of Seoul, Korea. Wet bulb, globe, and dry bulb temperatures were measured under direct sunlight from 1 O'clock to 5 O'clock pm. Globe and dry bulb temperatures were measured under street tree shades nearby during the same hours. Then the WBGTs were calculated with the formulae, one for sunny outdoor spaces, and the other for shaded outdoor spaces or indoor. The results are compared with the Korean Standards Association(KS A ISO 7243). The major findings were: 1) On very sunny and hot summer days in Seoul, street tree shades lower the WBGT about 1 to 4 degrees, 2) during the hours of 3 and 4 O'clock in the afternoon, the WBGT under the tree shades are about 3 to 4 degrees lower compared to those under sunshines(approx. 29 to 32 degrees respectively), 3) This difference makes a major thermal comfort for urban pedestrians because senior citizens or weak persons are recommended to move indoor, and even healthy people are recommended stop outdoor sports and take rests in the shades when WBGT is about 32. On the other hand, if the WBGT is around 29, or 3 degrees lower, slower walking, light works or sports are allowable, 4) On site questionnaire survey confirms the thermal comforts under the tree shades, and we even could not get survey subjects on the sunny parts of the sidewalks, 5) We strongly recommend change of guidelines for urban street trees from "one row of street trees on 6m~8m intervals" to "street trees to make continuous shades".

• Journal of Korea Water Resources Association
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• v.54 no.spc1
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• pp.1107-1118
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• 2021

Climate change brought on by global warming increased the frequency of flood and drought on the Korean Peninsula, along with the casualties and physical damage resulting therefrom. Preparation and response to these water disasters requires national-level planning for water resource management. In addition, watershed-level management of water resources requires flow duration curves (FDC) derived from continuous data based on long-term observations. Traditionally, in water resource studies, physical rainfall-runoff models are widely used to generate duration curves. However, a number of recent studies explored the use of data-based deep learning techniques for runoff prediction. Physical models produce hydraulically and hydrologically reliable results. However, these models require a high level of understanding and may also take longer to operate. On the other hand, data-based deep-learning techniques offer the benefit if less input data requirement and shorter operation time. However, the relationship between input and output data is processed in a black box, making it impossible to consider hydraulic and hydrological characteristics. This study chose one from each category. For the physical model, this study calculated long-term data without missing data using parameter calibration of the Soil Water Assessment Tool (SWAT), a physical model tested for its applicability in Korea and other countries. The data was used as training data for the Long Short-Term Memory (LSTM) data-based deep learning technique. An anlysis of the time-series data fond that, during the calibration period (2017-18), the Nash-Sutcliffe Efficiency (NSE) and the determinanation coefficient for fit comparison were high at 0.04 and 0.03, respectively, indicating that the SWAT results are superior to the LSTM results. In addition, the annual time-series data from the models were sorted in the descending order, and the resulting flow duration curves were compared with the duration curves based on the observed flow, and the NSE for the SWAT and the LSTM models were 0.95 and 0.91, respectively, and the determination coefficients were 0.96 and 0.92, respectively. The findings indicate that both models yield good performance. Even though the LSTM requires improved simulation accuracy in the low flow sections, the LSTM appears to be widely applicable to calculating flow duration curves for large basins that require longer time for model development and operation due to vast data input, and non-measured basins with insufficient input data.

• Korean Journal of Environment and Ecology
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• v.36 no.5
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• pp.445-459
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• 2022

In this study, we investigated current vegetation and assessed the health of vegetation through the KERVI (Korea Estuary Riparian Vegetation Index) to monitor vegetation changes near estuaries due to the opening of the Nakdong River estuary. As the first investigation of the long-term monitoring, six areas near the Nakdong River estuary were surveyed twice in July and October 2021, and vegetation monitoring and a survey of species composition and distribution density of aquatic, riparian, and land plants were carried out. The survey identified 262 taxa, 82 families, 192 genera, 196 species, 3 subspecies, 26 varieties, and 1 form of vascular plants in the surveyed area. The results of the vegetation health assessment through KREVI showed that sites 1 and 6 were rated "Very good" in both surveys, sites 2 and 4 were rated "Very good" in the first survey and then "Good"in the second survey, and site 3 and 5 were rated one grade higher in the second survey than the first survey. The assessment showed that the health grades of most species in the survey area were generally high. Most of the potential natural vegetation after the opening of estuary gates to create a brackish water area is expected to consist of reed (Phragmites communisTrin.) communities. The area of the willow (Salix koreensisAndersson) community adjacent to the water area may be somewhat narrower, but the community will be maintained. In the case of freshwater areas in inland areas with very low salinity, reeds (Phragmites communisTrin.) are expected to occupy most of them, and some communities such as amur silver-grass (Miscanthus sacchariflorusBenth.) and cattails (Typha orientalisC. Presl) are expected to be distributed. We suggest establishing measures such as estuary gate operation to create healthy brackish water regions through long-term monitoring.

• Journal of the Korean Geotechnical Society
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• v.37 no.3
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• pp.19-30
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• 2021

The presence of the hydrate-bearing sediments in Ulleung Basin of South Korea has been confirmed from previous studies. Researches on gas production methods from the hydrate-bearing sediments have been conducted worldwide. As production mechanism is a complex phenomenon in which thermal, hydraulic, and mechanical phenomena occur simultaneously, it is difficult to accurately conduct the productivity and stability analysis of hydrate bearing sediments through lab-scale experiments. Thus, the importance of numerical analysis in evaluating gas productivity and stability of hydrate-bearing sediments has been emphasized. In this study, the numerical parametric analysis was conducted to investigate the effects of the bottom hole pressure and the depressurization rate on the gas productivity and stability of hydrate-bearing sediments during the depressurization method. The numerical analysis results confirmed that as the bottom hole pressure decreases, the productivity increases and the stability of sediments deteriorates. Meanwhile, it was shown that the depressurization rate did not largely affect the productivity and stability of the hydrate-bearing sediments. In addition, sensitivity analysis for gas productivity and stability of the sediments were conducted according to the depressurization rate in order to establish a production strategy that prevents sand production during gas production. As a result of the analysis, it was confirmed that controlling the depressurization rate from a low value to a high value is effective in securing the stability. Moreover, during gas production, the subsidence of sediments occurred near the production well, and ground heave occurred at the bottom of the production well due to the pressure gradient. From these results, it was concluded that both the productivity and stability analyses should be conducted in order to determine the bottom hole pressure when producing gas using the depressurization method. Additionally, the stress analysis of the production well, which is induced by the vertical displacements of sediments, should be evaluated.