• Atmosphere
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• 제24권3호
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• pp.303-315
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• 2014

Terrestrial ecosystem plays the important role as carbon sink in the global carbon cycle. Understanding of interactions of terrestrial carbon cycle with climate is important for better prediction of future climate change. In this paper, terrestrial carbon cycle is investigated by Hadley Centre Global Environmental Model, version 2, Carbon Cycle (HadGEM2-CC) that considers vegetation dynamics and an interactive carbon cycle with climate. The simulation for future projection is based on the three (8.5/4.5/2.6) representative concentration pathways (RCPs) from 2006 to 2100 and compared with historical land carbon uptake from 1979 to 2005. Projected changes in ecological features such as production, respiration, net ecosystem exchange and climate condition show similar pattern in three RCPs, while the response amplitude in each RCPs are different. For all RCP scenarios, temperature and precipitation increase with rising of the atmospheric $CO_2$. Such climate conditions are favorable for vegetation growth and extension, causing future increase of terrestrial carbon uptakes in all RCPs. At the end of 21st century, the global average of gross and net primary productions and respiration increase in all RCPs and terrestrial ecosystem remains as carbon sink. This enhancement of land $CO_2$ uptake is attributed by the vegetated area expansion, increasing LAI, and early onset of growing season. After mid-21st century, temperature rising leads to excessive increase of soil respiration than net primary production and thus the terrestrial carbon uptake begins to fall since that time. Regionally the NEE average value of East-Asia ($90^{\circ}E-140^{\circ}E$, $20^{\circ}N{\sim}60^{\circ}N$) area is bigger than that of the same latitude band. In the end-$21^{st}$ the NEE mean values in East-Asia area are $-2.09PgC\;yr^{-1}$, $-1.12PgC\;yr^{-1}$, $-0.47PgC\;yr^{-1}$ and zonal mean NEEs of the same latitude region are $-1.12PgC\;yr^{-1}$, $-0.55PgC\;yr^{-1}$, $-0.17PgC\;yr^{-1}$ for RCP 8.5, 4.5, 2.6.

• Journal of the Korean earth science society
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• 제24권6호
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• pp.533-548
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• 2003

The prevailing wind phenomenon around Pohang in winter was investigated by using surface and vertical observatory datas and a numerical simulation was carried out to analyse this phenomenon using RAMS. Direction of the prevailing wind was westerly at upper atmosphere. However, near the surface, southwestern wind prevailed in winter. Using the RAMS to simulate a winter wind system numerically, it was found out that this phenomenon was strongly affected by the geographical features such as directions of coastline and low level valley, and distributions of land and sea. To investigate the accuracy of the model results, wind speed, temperature and wind direction of typical continuous southwestern wind occurring days were compared with observation data. Analyzing the characteristics of local circulation system was very hard because of horizontally sparse observation data. But from the result above, a numerical simulation using the RAMS, which satisfies the spatial high resolution, will provide more accurate results.

• Journal of Korean Society of Forest Science
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• 제97권3호
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• pp.229-236
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• 2008

The objectives of this study were to investigate inputs and pH values of stemflow of bulk precipitation and 5 tree species (Deciduous species : Quercus mongolica, Betula costata, Kalopanax septemlobus, Fraxinus rhynchophylla, Plantation species : Larix kaempferi), in Mt. Joongwang, Pyongchang-gun, Gangwondo, from June to October in 2004 and 2005. The amount of stemflow during study period was the greatest in Q. mongolica (9.9 mm), and B. costata (7.5 mm), K. setemlobus (5.9 mm), L. kaempferi (3.8 mm), F. rhynchophylla (3.2 mm), respectively. Stemflow of each species increased with bulk precipitation. Increment with bulk precipitation was smaller in 2004 when the intense bulk precipitation occurred more. pH values of stemflow was the highest in F. rhynchophylla (5.91), and K. setemlobus (5.64), B. costata (5.80), Q. mongolica (5.56), L. kaempferi (5.25), respectively. Generally, pH values of stemflow of all species increased with bulk precipitation pH value, and lower than that (6.39).

• Proceedings of the Korea Water Resources Association Conference
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• 한국수자원학회 2021년도 학술발표회
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• pp.254-254
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• 2021

기후변화로 인한 자연재해는 해마다 크게 증가하고있으며, 홍수 및 가뭄의 강도와 빈도 증가, 지구온난화로 인한 하천 건천화 등 많은 문제들이 대두되고 있다. 특히, 물 순환과정의 핵심요소로 설명되는 유출량의 변동은 용수 공급과 홍수 대응 및 관리, 하천생태계 유지를 위한 환경에 영향을 미치고 있다. 따라서, 갈수량, 풍수량 등을 산정하여 하천별 유황특성을 결정하는 방법을 사용하고 있으나, 이와같은 지표는 계측자료가 과소한 경우 하천의 유황특성을 세부적으로 이해하고 정량적으로 제시하는데에 한계가있다. 따라서, 미계측 유역에서 Soil and Water Assessment Tool (SWAT)과 같은 수리해석모델이 광범위하게 이용되고있으며, SWAT 모델은 유역의 수치표고모형, 토양 특성, 토지이용 현황, 기상 현황, 유역의 매개변수 등을 반영하여 모델이 구동되고 있다. 하지만, 광범위하게 이용되고 적용성이 입증된 모델임에도 불구하고 입력자료의 불확실성 및 조사되지 않은 영농활동 등으로 인해 결과에 불확실성이 내포되어있으며, 불확실성을 줄이기 위해 실측된 하천의 유량 자료를 이용하여 검정 및 보정작업을 거치고 있다. 모델의 보정 방법으로는 SWAT-CUP과 같은 프로그램 이용되고 있지만, 모델에서 이용되는 매개변수로는 보정할수 있는 범위가 한정적이기 때문에 모델의 정확성을 높이는데에 한계가 있다. 따라서, 본 연구에서는 선암천 유역을 대상으로 모델의 매개변수를 보정하지 않고도 머신러닝 기법을 이용하여 모델의 결과를 향상시켰다. 보정 결과, 유량의 경우 R²가 0.42에서 0.91으로 향상되었으며, 특히 고유량 구간에서의 정확성이 매우 향상되었다. 본 연구에서 평가된 SWAT+머신러닝 결합 모형은 향후 모델 구동에 필요한 입력자료가 부족한 경우와 빠른 검정 및 보정 작업이 필요할 경우 활용될수 있을것으로 판단된다.

• Land and Housing Review
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• 제8권4호
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• pp.249-256
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• 2017

Urbanization can be remarkable affected flood, pollutant loading, ecological system, and green infrastructure by distortion of hydrologic cycle. In order to mitigate these problems in urban, Low Impact Development(LID) technique has been introduced and applied in the world. SWMM model was calibrated with sets of field monitoring data and applied for calculation of runoff and pollutant loading in Asan-tangjung LID city under 2016 rainfall. Runoff reduction of watershed and catchment basins were showed efficiency 12.2% and 62.0%, respectively. Reduction of COD and TP loading also high efficiency in catchment basins were evaluated 74.9 and 71.4%. The results of this study can be used effectively in decision making processes of urban development project by comparing watershed runoff and pollutant reduction by designs of sort of LID technique, LID volume and location.

• Proceedings of the KSCN Conference
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• 대한지역사회영양학회 2003년도 추계학술대회
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• pp.1079-1079
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• 2003

최근 노인인구의 증가와 함께 식생활의 변화에 의해 사망원인의 변화가 일어나고 있다 한국인의 주요 사망원인 중 뇌혈관 및 심장질환 등 순환기계 질환에 의한 사망이 증가하고 있는 추세이며, 심장순환계 질환의 위험요인인 고혈압의 이환률도 65세 이상 노인에게서 증가하고 있다. 고혈압은 만성질환으로 산화적 스트레스를 증가시키는 질환이므로 본 연구에서는 건강한 노인과 고혈압 노인의 체내 항산화 영양상태를 비교하기 위해 울산지역 50세 이상 노인을 대상으로 하였다. 대조군은 질환이 없거나 골다공증, 위장질환과 같은 기타 질환을 가진 사람 96명이었으며, 고혈압환자군은 고혈압을 가진 모든 질환자 118명이었고, 항산화 영양소 섭취나 혈장내 항산화 영양상태에 영향을 미치는 성별, 연령, 흡연 및 음주상태를 보정하여 비교하였다. 고혈압환자의 평균 유병기간은 6.1년이었으며, 항산화 비타민 섭취량은 비타민 A, retinol, $\beta$-carotene과 비타민 C 섭취량 모두 고혈압 유무에 따른 유의적인 차이가 나타나지 않았으나 고혈압환자의 섭취량이 높은 경향을 보였다. 한국인영양권장량과 비교한 결과 대조군의 비타민 A 섭취는 권장량의 86.2%, 고혈압환자군은 권장량의 103.0%를 섭취하여 고혈압군에서 유의적으로 높았고, 권장량의 75% 이하 섭취자의 비율은 대조군에서 46.9%, 고혈압군에서 41.5%로 조사되었다. 비타민 C 섭취는 대조군에서 권장량의 176.6%, 고혈압군에서는 189.0%로 나타나 질환의 유무에 관계없이 두 군 모두 권장량의 170%이상을 섭취하고 있었으나 권장량의 75% 이하를 섭취하는 사람의 비율이 대조군에서 13.5%, 고혈압군에서 17.0%로 고혈압군에서 높게 나타났다. 혈장 비타민 C의 농도는 대조군 15.3 mg/L, 고혈압환자 15.9mg/L, 혈장 $\beta$-carotene 농도는 대조군 0.21mg/L, 고혈압환자 0.22 mg/L로 나타나 고혈압 유무에 따른 차이가 없었고, 혈장 비타민 A,E 농도 및 총 항산화능력은 대조군에 비해 고혈압환자에게서 유의적으로 높게 나타났다. 또한 혈장 지질과산화물의 농도도 유의적이지는 않지만 고혈압환자에게서 높은 경향이 나타났다. 따라서 고혈압에 따른 항산화 영양상태를 비교한 결과 전반적인 항산화 비타민의 섭취량, 혈중 비타민 농도 및 총 항산화능력이 예상과 달리 대조군 보다 고혈압환자에게서 유의적으로 높게 나타났다. 이런 결과는 질환자들이 자신이 가진 질병의 진전을 막거나 치료의 목적으로 치료제를 복용하고, 식이요법을 실시하고 있기 때문으로 사료되며, 고혈압과 같이 산화적 스트레스가 증가하는 질환의 경우 체내 항산화 체계 반응이 이러한 변화에 효율적으로 대처하기 위한 방향으로 증가되었을 가능성이 있을 것으로 사료된다. 특히, 본 연구의 대상자들의 유병기간이 6.1년으로 비교적 길기 때문에 질환의 진행정도에 따른 항산화 상태를 측정하거나 비교적 질환으로 판정된 직후의 사람들의 대상으로 한 연구 등 더 많은 연구가 필요하다.

• Journal of the Korea Society of Computer and Information
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• 제29권3호
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• pp.137-146
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• 2024

The purpose of this study was to determine the effects of 12 weeks of WB-EMS training on body composition and heart rate variability based on BMI Level in Women. The subjects of the study were premenopausal women, and they were classified into the BMI-N(n=15) group for BMI<25, the BMI-1(n=16) group for BMI=25~29.9, and the BMI-2(n=9) group for BMI>30. And then, WB-EMS training was performed of 3 times a week for 12 weeks. Body composition and HRV were measured before and after the participation in exercise, which were subjected to a repeated-measures two-way ANOVA. In the case of a significant interaction between time and group, paired sample t-tests were conducted for a post-hoc analysis within each subject group. Tukey's method was used for post-hoc testing of differences between groups, and the significance level was set at 0.5. The results were as follows; First, The effect of WB-EMS training was found in all variables of body composition. In particular, Weight, BMI, FFM, and FM decreased the most in the BMI-2 group, followed by the BMI-1 and BMI-N groups. %BF and VF decreased the most in the BMI-2 group. Second, There was a difference in BPM in all groups, and the BMI-2 group showed the greatest decrease. There were differences in SDNN and RMSSD for each group, and there was no difference according to obesity level. There was no difference in LF, HF, and LF/HF ratio. In conclusion, it was confirmed that WB-EMS training can be an exercise therapy that has a positive effect on the body composition change and cardiac circulatory system in women with a high level of obesity.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• 제24권2호
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• pp.208-225
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• 2019

To understand the mean surface circulation and surface currents in the East Sea, trajectories of surface drifters passed through the East Sea from 1991 to 2017 were analyzed. By analyzing the surface drifter trajectory data, the main paths of surface ocean currents were grouped and the variation in each main current path was investigated. The East Korea Warm Current (EKWC) heading northward separates from the coast at $36{\sim}38^{\circ}N$ and flows to the northeast until $131^{\circ}E$. In the middle (from $131^{\circ}E$ to $137^{\circ}E$) of the East Sea, the average latitude of the currents flowing eastward ranges from 36 to $40^{\circ}N$ and the currents meander with large amplitude. When the average latitude of the surface drifter paths was in the north (south) of $37.5^{\circ}N$, the meandering amplitude was about 50 (100) km. The most frequent route of surface drifters in the middle of the East Sea was the path along $37.5-38.5^{\circ}N$. The surface drifters, which were deployed off the coast of Vladivostok in the north of the East Sea, moved to the southwest along the coast and were separated from the coast to flow southeastward along the cyclonic circulation around the Japan Basin. And, then, the drifters moved to the east along $39-40^{\circ}N$. The mean surface current vector and mean speed were calculated in each lattice with $0.25^{\circ}$ grid spacing using the velocity data of surface drifters which passed through each lattice. The current variance ellipses were calculated with $0.5^{\circ}$ grid spacing. Because the path of the EKWC changes every year in the western part of the Ulleung Basin and the current paths in the Yamato Basin keep changing with many eddies, the current variance ellipses are relatively large in these region. We present a schematic map of the East Sea surface current based on the surface drifter data. The significance of this study is that the surface ocean circulation of the East Sea, which has been mainly studied by numerical model simulations and the sea surface height data obtained from satellite altimeters, was analyzed based on in-situ Lagrangian observational current data.

• Journal of Korean Society of Coastal and Ocean Engineers
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• 제31권6호
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• pp.434-449
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• 2019

In this study, we develop a new cross-shore sediment module which takes the effect of infra-gravity waves of bound mode, and boundary layer streaming on the sediment transport into account besides the well-known asymmetry and under-tow. In doing so, the effect of individual random waves occurring during the unit observation period of 1 hr on sediment transport is also fully taken into account. To demonstrate how the individual random waves would affect the sediment transport, we numerically simulate the non-linear shoaling process of random wavers over the beach of uniform slope. Numerical results show that with the consistent frequency Boussinesq Eq. the application of which is lately extended to surf zone, we could simulate the saw-tooth profile observed without exception over the surf zone, infra-gravity waves of bound mode, and boundary-layer streaming accurately enough. It is also shown that when yearly highest random waves are modeled by the equivalent nonlinear uniform waves, the maximum cross-shore transport rate well exceeds the one where the randomness is fully taken into account as much as three times. Besides, in order to optimize the free parameter K involved in the long-shore sediment module, we carry out the numerical simulation to trace the yearly shoreline change of Mang-Bang beach from 2017.4.26 to 2018.4.20 as well, and proceeds to optimize the K by comparing the traced shoreline change with the measured one. Numerical results show that the optimized K for Mang-Bang beach would be 0.17. With K = 0.17, via yearly grand circulation process comprising severe erosion by consecutively occurring yearly highest waves at the end of October, and gradual recovery over the winter and spring by swell, the advance of shore-line at the northern and southern ends of Mang-Bang beach by 18 m, and the retreat of shore-line by 2.4 m at the middle of Mang-Bang beach can be successfully duplicated in the numerical simulation.

• Journal of the Korean Society of Food Science and Nutrition
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• 제35권4호
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• pp.402-409
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• 2006

This study was performed to investigate the effects of Capsosiphon fulvescens (CF) extract on serum and liver lipid metabolism in rats. Male Sprague-Dawley rats were administered 1% cholesterol and 0.25% sodium cholate to induce hypercholesterolemia and were divided into six groups. Experimental groups were administered with following diets; normal diet group (NC), high cholesterol diet group (HC), normal diet and CF extract (200 mg/kg) administered group (NC-CFL), normal diet and CF extract (400 mg/kg) administered group (NC-CFH), high cholesterol diet and CF extract (200 mg/kg) adwlinistered group (HC-CFL), and high cholesterol diet and CF extract (400 mg/kg) administered group (HC-CFH). The body weight gain and feed efficiency ratio were increased by high cholesterol diet, but gradually decreased to the corresponding level of the normal diet group by administered CF extract. The serum total cholesterol concentration of normal diet group was significantly higher than those of NC-CFL group and NC-CFH group. The concentrations of serum total cholesterol LDL-cholesterol and triglyceride and the atherogenic index .were tended to decrease in the CF extract administered groups compared with the high cholesterol diet group. However, HDL-cholesterol and phospholipid concentrations in serum decreased in the high cholesterol diet group and markedly increased by the CF extract administered groups. There were no differences in the concentrations of serum triglyceride, phopholipid, LDL-cholesterol, HDL-cholesterol and free cholesterol in normal diet groups. Concentrations of total cholesterol and triglyceride in liver and kidney were also markedly decreased in the CF administered groups. Total cholesterol and triglyceride concentrations of adipose tissue in the CF administered groups were also decreased compared with the high cholesterol diet group. In addition, there were no differences in the concentrations of liver, kidney and adipose tissue total lipid, triglyceride and total cholesterol in normal diet groups. The activities of heparin-releasable lipoprotein lipase (LPL) and total-extractable LPL in adipose tissue were increased in the high cholesterol diet group compared with the CF extract administered groups, but those of the NC -CFL group and NC-CFH group were similar to the normal diet group. Taken together, it is suggested that the extract of CF have an antiatherosclerotic effect by reducing cholesterol level of serum and liver. Furthermore, the extract of CF decreased LPL activity and triglyceride concentration, resulting in less lipid storage.