• Journal of Music and Human Behavior
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• v.7 no.2
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• pp.65-81
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• 2010

This single case study is to examine the gait parameter changes of a 12-year old patient with Cerebellar Astrocytomas using RAS in gait training program. Kinematic and temporospatial changes were analyzed using VICON 370 Motion Analysis System. A total of nine RAS gait training sessions was provided and each training program took 30 minutes. Gait analysis revealed that the patient showed improvement in cadence, velocity, stride length, and step length and improved the range of joint movements by showing gait patterns similar to normal distribution from a pathological pattern. This study showed possibilities to apply the RAS technique to the various population including clients with cerebellum damaged; however more further research should be done in this area.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.30 no.3B
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• pp.295-303
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• 2010

The variability of vegetation is strongly related to the variability of hydrometeorological factors such as precipitation, temperature, runoff and so on. Analysis of the variability of vegetation will aid to understand the regional impact of climate change. Thus we analyzed the spatial-temporal variability of NOAA(National Oceanic and Atmospheric Administration)/AVHRR(Advanced Very High Resolution Radiometer) NDVI(Normalized Difference Vegetation Index). In the results from Mann-Kendall test, there is no significant linear trend of annual NDVI from 1982 to 2006 in the most area except the downward trend on the significance level 90% in the Guem-river basin area. In addition, using EOF(Empirical Orthogonal Function) analysis, the variability of NDVI in the region of higher latitude and altitude is higher than that in the other region since the spatial variability of NDVI follows the latitudinal gradient. Also we could get higher NDVI in June, July, August and September. We had the highest NDVI in Han-river basin area and the lowest in Je-Ju island.

• Proceedings of the Korea Water Resources Association Conference
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• 2022.05a
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• pp.414-414
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• 2022

본 연구는 2022년도 "제주특별자치도 수자원 부존현황 조사 및 분석 사업"의 연구비 지원에 의해수행되었습니다.최근 IPCC 제6차 평가보고서(AR6)에 새롭게 적용된 미래 기후변화 시나리오인 SSP (Shared Socioeconomic Pathways)에 따른 제주도 지역의 미래 기후변화를 강수량, 기온, 기준증발산 등을 중심으로 분석하였다. 미래의 기후변화 자료로서 19개의 GCM 모형으로부터 도출된 4개의 SSP 시나리오(SSP1-2.6, SSP2-4.5, SSP3-7.0, SSP5-8.5)를 활용하였다. 제주도 지역의 3개 기상청 ASOS 지점(제주, 성산, 서귀포)을 대상으로 상세화된 기후변화 자료를 이용하여 지점별 및 지역별 미래 전망을 분석하였다. 기준증발산량은 기온자료만을 이용하는 Thornthwaite 방법을 활용하여 산정하였으며, FAO-56 Penman-Monteith 기준증발산량과의 차이를 최소화하기 위하여 시공간적 보정계수를 적용하였다. 과거기간(1985~2014년)을 기준으로, 미래기간(2021~2095년)을 3개 구간(2021~2045년, 2046~2070년, 2071~2095년)으로 나누어 분석하였다. 제주도 전체에 대한 평균적인 전망은 대부분의 SSP 시나리오에서 강수량, 기온, 기준증발산량 모두 미래 후반기로 갈수록 점차 증가하는 경향을 보였으며, SSP1-2.6 시나리오에서만 기온과 기준증발산량이 미래 전반기(2021~2045년)에는 크게 증가하다가 중반기(2046~2070년)와 후반기(2071~2095년)에는 비교적 일정한 것으로 전망되었다. 과거기간과 비교하여 미래 후반기 SSP5-8.5 시나리오에서 가장 크게 증가하는 것으로 전망되었으며, 강수량은 17%, 기온은 38%, 기준증발산량은 58%까지 증가하는 것으로 분석되었다. 지점별로는 제주 지점이 다른 2개 지점(성산, 서귀포)에서보다 더 많이 증가할 것으로 전망되었다. 제주 지점의 경우 SSP5-8.5 시나리오에서 연 강수량은 19%, 평균기온은 42%, 기준증발산량은 70%까지 증가하는 것으로 나타났다. 증가되는 크기는 강수량은 서귀포, 성산, 제주 지점 순으로 전망되었으며, 기온과 기준증발산량은 반대로 제주, 성산, 서귀포 순으로 증가량이 클 것으로 전망되었다. 그러나 GCM 모형에 따라 전망결과가 다양하게 나타나기 때문에 이에 대한 불확실성을 고려한 미래 대응이 필요하다.

• Korean Journal of Ecology and Environment
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• v.41 no.2
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• pp.206-215
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• 2008

Temporal and spatial distributions of salinity, temperature, dissolved oxygen (DO), and turbidity were investigated at seven sites in the upper regions of brackish Lake Sihwa with a limited water exchange, from March to October 2005. During the study period, salinity and temperature varied $0.1{\sim}29.9\;psu$ and $4.7{\sim}28.1^{\circ}C$, respectively, depending on seasons and sites sampled. A distinct halocline profile showing the maximum density gradient (difference over $20\;psu\;m^{-1}$ between surface and bottom layers) was observed during the rainy season, due to the decrease of salinity in surface layers by freshwater inflow. This result implies that rainfall event is the important factor forming the halocline. On the other hand, the depth and location of haloeline varied with the amount of seawater through the sluice gates and the operation systems (inflow or outflow). High DO (over 300% saturation) was observed at surface layer above the halocline in April when red tide occurred, whereas low DO (below 20% saturation) was at the bottom layer below the halocline in the rainy season. Turbidity ranged $1.5{\sim}80.3\;NTU$ showing the maximum turbidity at the layers above or upper the halocline. As a result, the distributions of DO and turbidity in the upper regions of brackish Lake Sihwa were largely affected by the variation of salinity. Also, when the halocline was formed, the water quality between upper and lower water layers may be expected completely different. This study suggests that the physicochemical characteristics of water in the brackish regions are closely associated with the causes of eutrophication such as red tide and DO deficit.

• Journal of Environmental Policy
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• v.4 no.2
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• pp.83-101
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• 2005

Because of its strong potential for health hazards, the concentration levels of airborne lead (Pb) have been circumscribed by environmental laws in many countries. In this study, we made a comparative study on the environmental behavior of Pb for the acquisition of its distribution characteristics using data sets collected from major cities in Korea for a period of 6 years (1998 through 2003). According to this study, Pb concentration decreased slowly in most industrialized cities of Koreathroughout the whole study. period. In contrast, such temporal signals were not evident in data sets collected from residential, commercial, and grassland areas. Although seasonal patterns generally exhibited the occurrences of high Pb concentration during the spring, results appear to reflect the influence of Asian Dust (AD) in the springtime. The results of our study clearly indicate that Pb distribution is strongly influencedby source types in relation to their land use patterns. Comparison of our Pb data sets with that of other countries indicates that Pb concentration levels obtained from relatively cleaner districts of Korea are still significantly higher than other countries. The results of this analysis generally indicate that Pb concentrations in most areas are affected by the type and strength of man-made activities. Considering that most areas are affected by a variety of pollutants, continuous efforts are needed to control Pb concentrations in the atmosphere.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.24 no.5
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• pp.333-342
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• 2012

We studied the characteristics of spatial distribution of global wave height and carried out the modelsensitivity test by changing the input field, model resolution and physical factor (effective wind factor) since the spatial and temporal resolution in wind wave forecasting is one of most important factors. Comparisons among the different cases, and also between model, buoy and satellite data have been made. As a results of the wind-wave model run using the high resolution wind field, the bias of significant wave height showed the positive tendency and the Root-Mean Square Error(RMSE) was a bit decreased based on the comparison with buoy data. When the model resolution was changed to higher, the bias and RMSE was increased, and as the effective wind factor was smaller than default value(= 1.4) the bias and RMSE showed also decreasing pattern.

• Economic and Environmental Geology
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• v.51 no.1
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• pp.15-26
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• 2018

The spatio-temporal variations of nitrate concentrations in groundwater of Jeju Island were evaluated by an analysis of time series groundwater quality data (N = 21,568) that were collected from regional groundwater monitoring (number of wells = 4,835) for up to 20 years between 1993 and 2015. The median concentration of $NO_3-N$ is 2.5 mg/L, which is slightly higher than those reported from regional surveys in other countries. Nitrate concentrations of groundwater in wells tend to significantly vary according to different water usage (of the well), administrative districts, and topographic elevations: nitrate level is higher in low-lying agricultural and residential areas than those in high mountainous areas. The Mann-Kendall trend test and Sen's slope analysis show that nitrate concentration in mid-mountainous areas tends to increase, possibly due to the expansion of agricultural areas toward highland. On the other hand, nitrate concentrations in the Specially Designated Groundwater Quality Protection Zones show the temporally decreasing trend, which implies the efficiency of groundwater management actions in Jeju. Proper measures for sustainable groundwater quality management are suggested in this study.

• Korean Journal of Remote Sensing
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• v.37 no.6_1
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• pp.1589-1597
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• 2021

Submarine groundwater discharge (SGD) in coastal areas is gaining importance as a major transport route that bring nutrients and trace metals into the ocean. This paper describes the analysis of the seasonal changes and spatiotemporal characteristicsthrough the modeling monthly SGD for 35 years from 1986 to 2020 for the Nakdong river basin. In this study, we extracted 210 watersheds and SGD estimation points using the SRTM (Shuttle Radar Topography Mission) DEM (Digital Elevation Model). The average annual SGD of the Nakdong River basin was estimated to be 466.7 m²/yr from the FLDAS (Famine Early Warning Systems Network Land Data Assimilation System) recharge data of 10 km which is the highest resolution global model applicable to Korea. There was no significant time-series variation of SGD in the Nakdong river basin, but the concentrated period of SGD was expanded from summer to autumn. In addition, it was confirmed that there is a large amount of SGD regardless of the season in coastal area nearby large rivers, and the trend has slightly increased since the 1980s. The characteristics are considered to be related to the change in the major precipitation period in the study area, and spatially it is due to the high baseflow-groundwater in the vicinity of large rivers. This study is a precedentstudy that presents a modeling technique to explore the characteristics of SGD in Korea, and is expected to be useful as foundational information for coastal management and evaluating the impact of SGD to the ocean.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.24 no.1
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• pp.92-105
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• 2019

Spatial and temporal characteristics of phytoplankton communities around the coastal waters of Jeju Island were investigated with environmental factors such as water temperature, salinity, and dissolved oxygen. Monthly samples were collected at 0 and 30 m depths of 10 stations from March 2015 to February 2016. During the survey period, water temperature ranged in 13.7~25.9 and $13.6{\sim}20.8^{\circ}C$ at 0 and 30 m, salinity in 31.51~34.47 and 33.03~34.47 psu at 0 and 30 m, and dissolved oxygen in 6.12~8.10 and $5.73{\sim}7.88mg\;L^{-1}$ at 0 and 30 m, respectively. Chlorophyll-a ranged in 0.28~2.48 and $0.44{\sim}1.01{\mu}g\;L^{-1}$ at 0 and 30 m, respectively. Phytoplankton abundance fluctuated in the range of $5,300{\sim}639,900cells\;L^{-1}$ during the year, showing the lowest in February at all stations, and the highest in July at the northern and western sea as well as in August at the southern and eastern sea of Jeju Island. A total of 362 species were occurred including 181 spp. of Bacillariophyta, 147 spp. of Dinophyta and 34 spp. of other phytoflagellates. Dominant species with occupancy rate over 20 percent of phytoplankton abundance showed apparent seasonal succession such as Paralia sulcata and Skeletonema costatum in spring and autumn, 6 spp. of genus Chaetoceros in summer, and 2 spp. of genus Chaetoceros and Thalassionema frauenfeldii in winter. Monthly abundance in the northern and western sea fluctuated with similar tendency, and the southern and eastern sea also showed similar pattern of monthly abundance variation. Species composition and dominant species succession mentioned above were quite different from previous studies, so some physical changes such as water temperature, salinity and current pattern might cause the changes of phytoplankton assemblages around Jeju Island.

• Journal of the Korean earth science society
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• v.32 no.1
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• pp.21-32
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• 2011

Using six-year (2004-2009) SKYNET measurements, MODIS-derived AOTs were validated at five SKYNET sites (Seoul, Chiba, Etchujima, Fukuejima, and Hedomisaki), in addition to climatological analysis of MODIS-derived optical properties over the East Asian domain ($20-50^{\circ}N$, $90-150^{\circ}E$). In so doing MODIS-SKYNET collocated AOT data were constructed if two measurements are taken within 25 km distance and within 30 minute time difference. From the comparison of two measurements, it is demonstrated that aerosol type insignificantly affects the accuracy of MODIS AOT. It is because the aerosol model combining predefined fine aerosol model and coarse aerosol model is used for the retrieval. However, positive bias between MODIS and SKYNET increases as fraction of the coarse aerosol model increases. In addition, MODIS AOT appears to be overestimated in case of lower aerosol loading while the overestimation tends to decrease with increased aerosol loading. Regression analysis between MODIS AOT and SKYNET AOT for 550 nm band yields 0.86, 0.16, and 0.61 of regression slope, intercept, and coefficient of determination, respectively. Those statistical results may draw a conclusion that MODIS AOTs over East Asia carry a reasonable accuracy compared to ground-based SKYNET measurements.