• The Journal of Engineering Geology
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• v.18 no.2
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• pp.167-176
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• 2008

The variation characteristics of groundwater level with distance from shoreline at Jeju Island was investigated using groundwater level data monitored from 257 wells for dry season (December 1998) and wet season (July 1997), respectively. Groundwater levels of the dry season were $7.46{\sim}203.8\;m$ with an average of 60.49 m, while those of the wet season were $4.01{\sim}204.10\;m$ with an average of 57.66 m. Groundwater level of the dry season was higher than that of the wet season, which was caused by heavy rains between June and October, 1998 at the Jeju Island. Correlation coefficients between altitude and groundwater level for dry and wet seasons were above 0.86, and those between dry season and wet season groundwater levels were very high above 0.95. 257 groundwater level data were classified at an interval of 500 m. Average values for altitude, groundwater levels and distance from shoreline were calculated for 17 intervals. Altitude and groundwater level fur dry and wet seasons at $0{\sim}4\;km$ intervals were increased with distance from shoreline, but those at $4{\sim}9\;km$ intervals were irregularity. Linear functions of the groundwater level for dry and wet seasons as distance from shoreline were estimated, and the coefficient of determinant at $0{\sim}4\;km$ interval data was higher than it at $0{\sim}9\;km$ interval data. Increasing rate of groundwater level at $0{\sim}4\;km$ intervals was more 2 times than it at $0{\sim}9\;km$ intervals. This results are caused by linear increase of groundwater level to 4 km from shoreline and by irregularity of groundwater level at the $4{\sim}9\;km$ intervals.

• Journal of Chest Surgery
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• v.34 no.10
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• pp.754-762
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• 2001

Background: To evaluate the efficacy of arterial switch operation for transposition of great arteries, serial echocardiographic studies were performed in 8 patients who underwent the surgery between 1989 and 1998 at Dept. of Thoracic & Cardiovascular Surgery, Yeungnam University Hospital in Daegu City, Korea. Material and Method: Follow-up period ranged from 6 months to 11 years(average of 4.1 years). Body weight ranged from 2.6kg to 4.8kg, with average of 3.6kg. 5 of 8 patients were preoperatively diagnosed as TGA+VSD, and 3 as TGA+IVS. LV function was evaluated by the measurement of LV shortening fraction, LVSTI, and LVEF. RVSTI was also measured. Postoperative function of valve and growth of great vessels were analyzed by the measurement of PSPGV, valvular regurgitation, LA/AO ratio, root dimension of aorta and pulmonary artery, comparing with the age matched controls, respectively. Result: LVEF had an average of 65.0+9.03% which is tended to increase serially. LVAOPG had an average of 15.9mmHg. RVPAPG, 27.5mmHg. From the measurement of aortic root dimension of 6 patients at end-systole, aortic root growth was assumed to increase more than the mean value of normal growth. PA root dimension at end-systole showed a similar growth progress when compared with age matched normal controls. Postoperative pulmonic valve regurgitation was noted in 5 of total 8 patients, in which 1 patient who showed grade 2 and 4 showed below grade 1. AR, in 6 patients and all grade 1 Except 1 patient, all the valvular regurgitations were below grade 1, which was presumed to be clinically insignificant.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.18 no.4
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• pp.163-177
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• 2013

An instrumented ferry made two transects per day across two current systems which are the North Korean Cold Current and the East Korean Warm Current over the years 2012-2013 from Gangneung to Ulleungdo in the southwestern East Sea. Seawater properties of these transects were measured with high spatial and temporal resolution for an extended period of time. Here the salinity records from the transects with the oceanographic observation data from East Sea Fisheries Institute of NFRDI, AVISO daily current chart and GOCI Chlorophyll-a image in 2012 and 2013 are used to study the time-series variation of salinity at the surface. The high salinity section with the range of 33.15~34.12 occurred on the transect mainly in the middle of eddy, and western boundary of strong northward current from June to October. We can found low salinity waters in both sides of the high salinity section. It is estimated that the western low salinity waters with the range of 30.58~33.20 accompanied by southward current were derived from the NKCC and the eastern waters with the range of 31.30~33.24 accompanied by northward current were derived from the Tsushima Surface Water. The lowest salinity of NKCC is confirmed in this study as 30.36. It is found that the western waters below 33.00 extended extremely toward the east about 110 km area from Gangneung and toward the south around Jukbyon coastal area as a 5~10 m layer. We can find its volume of low saline waters transport is not neglectable compared with that of Tsushima Current region in the western part of the East Sea. In this study we named it as the North Korean Low Saline Surface Water in summer.

• Korean Journal of Environmental Biology
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• v.36 no.4
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• pp.647-658
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• 2018

The aim of this study is to investigate the seasonal changes of phytoplankton communities based on the environmental changes in a dense oyster farming area (Hansan-Geoje Island) from June to December 2016. The water temperature varied from $14^{\circ}C$ to $28.8^{\circ}C$ and its salinity ranged from 29.4 to 34.2 psu. Nitrate+nitrite was kept at c.a. $3.0{\mu}M$ on the surface layer from June to July, below the concentration limit in August and early September, and then gradually increased from late September. Ammonia was high on July 20 and August 10, and its seasonal characteristics were not clear. Phosphate ranged from 0.01 to $0.7{\mu}M$ on the surface layer, and its seasonal changes were similar to those of nitrate+nitrite. Mean silicate concentrations were $10.7{\mu}M$ on the surface and $15.7{\mu}M$ in the bottom layer, and it was not acted as a limiting factor for the growth of phytoplankton. Among the phytoplankton community, Bacillariophyceae, Dinophyceae and Cryptophyceae was 61.2%, 22.5%, and 13.6%, respectively. In late June, dinoflagellate Prorocentrum donghaiense was dominant in the outer waters(St. T1), later on, Cryptomonas spp. and Chaetoceros spp. were dominant, respectively. From late September to October, diatoms Pseudo-nitzschia spp. and Chaetoceros spp. were stimulated under non-stratified condition after the typhoon. In December, A. sanguinea was found to be $1.7{\times}10^5cells\;L^{-1}$. Seasonally, relative high phytoplankton biomass may be favorable to maintain high production of filter feeder oyster in the dense oyster farming areas of Hansan and Geoje Island.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.14 no.3
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• pp.134-144
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• 2009

Paleoproductivity changes in the central part of the Bering Sea since the last glacial period were reconstructed by analyzing opal and total organic carbon (TOC) content and their mass accumulation rate (MAR) in sediment core PC23A. Ages of the sediment were determined by both AMS $^{14}C$ dates using planktonic foraminifera and Last Appearance Datum of radiolaria (L. nipponica sakaii). The core-bottom age was calculated to reach back to 61,000 yr BP. and some of core-top was missing. Opal and TOC contents during the last glacial period varied in a range of 1-10% and 0.2-1.0%, and their average values are 5% and 0.7%, respectively. In contrast, during the last deglaciation, opal and TOC contents varied from 5 to 22% and from 0.8 to 1.2%, respectively, with increasing average values of 8% and 1.0%. Opal and TOC MAR were low ($1gcm^{-2}kyr^{-1}$, $0.2gcm^{-2}kyr^{-1}$) during the last glacial period, but they increased (>5 and >$1gcm^{-2}kyr^{-1}$) during the last deglaciation. High diatom productivity during the last deglaciation was most likely attributed to the elevated nutrient supply to the sea surface resulting from increased melt water input from the nearby land and enhanced Alaskan Stream injection from the south under the restricted sea-ice and warm condition during the rising sea level. On the contrary, low productivity during the last glacial period was mainly due to decreased Alaskan Stream injection during the low sea-level condition as well as to extensive development of sea ice under low-temperature seawater and cold environment.

• Korean Journal of Ecology and Environment
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• v.40 no.2
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• pp.273-284
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• 2007

The spatial and temporal zooplankton dynamics were examined along ca. 100-km section of the middle to lower Seomjin River (without estuary dam in river mouth) and Youngsan River (with estuary dam in river mouth) systems during study periods (2004. Nov.${\sim}$2006. Aug.) based on a monthly sampling intervals. The spatial variation of zooplankton biomass at both river ecosystems was distinct. There was considerable longitudinal variation in total zooplankton abundance in Youngsan R. stretch. The increase in total zooplankton abundance were observed along the longitudinal stretch toward the estuary dam. In contrast, there were not statistically significant longitudinal differences in total zooplankton abundance in Seomjin R. stretch. In Youngsan R. stretch, average abundance of total zooplankton (average ranges: $199{\sim}817$ Ind. $L^{-1}$ at 3 sampling sites, n=20) were nearly $4{\sim}60$ fold higher than that of Seomjin R. stretch (average ranges: $12{\sim}43$ Ind. $L^{-1}$ at 4 sampling sites, n=20). Relative abundance of rotifers (over 80% of total zooplankton abundance) at the whole sampling sites in Youngsan R. stretch were Much higher than that of the Seomjin R. stretch. The most abundant rotifers were Polyarthra spp., Brachionus spp., Colurella spp., and Keratella spp. at the both river ecosystems. In Seomjin R. stretch, copepods carbon biomass sharply increased toward in river mouth (over 40% of total zooplankton carbon biomass). Average ranges of total zooplankton filtering rates for phytoplankton at both river ecosystems varied from 21.2 to 92.9 mL $L^{-1}\;D^{-1}$ in Youngsan R. stretch and from 2.1 to 2.6 mL $L^{-1}\;D^{-1}$ in Seomjin R. stretch. Considering the zooplankton filtering rates, zooplankton as grazers of phytoplankton in Youngsan R. stretch seemed to play the more important role in planktonic food web than that of the Seomjin R. stretch.

• Pediatric Infection and Vaccine
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• v.21 no.1
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• pp.9-21
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• 2014

Purpose: To determine the clinical significance of voriconazole therapeutic drug monitoring (TDM) in the pediatric population. Methods: Twenty-eight patients with invasive fungal infections administered with voriconazole from July 2010 to June 2012 were investigated retrospectively. Fourteen received TDM, and 143 trough concentrations were analyzed. All 28 patients were assessed for adverse events and treatment response six weeks into treatment, and at the end. Results: Out of 143 samples, 53.1% were within therapeutic range (1.0-5.5 mg/L). Patients administered with the same loading (6 mg/kg/dose) and maintenance (4 mg/kg/dose) dosages prior to initial TDM showed highly variable drug levels. Adverse events occurred in 9 of 14 patients (64.3%) in both the TDM and non-TDM group. In the TDM group, voriconazole-related encephalopathy (n=2, 14.3%) and aspartate aminotransferase (AST) or alanine aminotransferase (ALT) elevation (n=8, 57.1 %) occurred with serum levels in the toxic range (>5.5 mg/L), whereas blurred-vision (n=2, 14.3%) occurred within the therapeutic range (1.18 mg/L and 3.9 mg/L). The frequency of voriconazole discontinuation due to adverse events was lower in the TDM group (0.0% vs. 18.2%, P =0.481). Overall, 57.2% of the patients in the TDM group versus 14.3% in the non-TDM group showed clinical response after 6 weeks (P =0.055), whereas 21.4% in the TDM group versus 14.3% in the non-TDM group showed response at final outcome (P =0.664). In the TDM group, >67.0% of the serum levels were within therapeutic range for the first 6 weeks; however 45.5% were within therapeutic range for the entire duration. Conclusion: Routine TDM is recommended for optimizing the therapeutic effects of voriconazole.

• Korean Journal of Soil Science and Fertilizer
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• v.45 no.6
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• pp.968-972
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• 2012

Soil chemical properties of agricultural soils in Korea were investigated at four-years interval in order of paddy, plastic film house, upland, and orchard soils since 1999. Paddy soil samples were taken from the surface 15 cm at 4,047, 2,010, 2,110 and 2,110 sites in all provinces of South Korea in 1999, 2003, 2007 and 2010, respectively. Soil chemical properties in Korea except Jeju province were measured. Soil pH and exchangeable calcium and available silicate contents increased with increasing the application rate of silicate fertilizer and with decreasing its application interval. Soil organic matter content also increased from $22.0g\;kg^{-1}$ in 1999 to $26.0g\;kg^{-1}$ in 2011. Average concentration of available phosphate in 2011 was higher than the upper limit of its optimal range for rice cultivation. However, exchangeable magnesium and available silicate contents were below the lower limit of their optimal ranges, which were 80% and 92% of them, respectively.

• Journal of the Korean Society of Marine Environment & Safety
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• v.19 no.6
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• pp.570-581
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• 2013

To improve productivity of aquaculture animals with management of culturing grounds, survey of mariculture management area in Ongjin-gun about water quality and sedimentary environment had been conducted on June, August and November in 2011. Water temperature in surface and bottom waters ranged from 9.49 to $24.14^{\circ}C$. Salinity and dissolved oxygen concentrations were in the range of 23.19~31.49 and 5.48~9.36 mg/L, respectively, depending on the variation of water temperature. The average concentration of COD was 1.57 mg/L and the concentrations of DIN and DIP showed entirely low level. As the result of grain size analysis, sand(56.66 %) and silt(34.60 %) were predominated. The Mz of sediment showed a variation of 2.59 to $6.62{\O}$ and sorting appeared to be poorly sorted. The concentrations of COD and IL in surface sediment ranged from 1.00 to $11.03mg/g{\cdot}dry$ and 0.72 to 5.29 %, respectively, which showed relatively good positive correlations. On the environmental assessment of trace metals in surface sediment, geoaccumulation index ($I_{geo}$) class indicated that sediments were not contaminated by most of metallic elements except Cr and As. Our result implies that this study area showed good water quality and sediments were not polluted by organic matters and metallic elements.

• Progress in Medical Physics
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• v.26 no.4
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• pp.280-285
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• 2015

In radiation therapy fields, a brachytherapy is a treatment that kills lesion of cells by inserting a radioisotope that keeps emitting radiation into the body. We currently verify the consistency of radiation treatment plan and dose distribution through film/screen system (F/S system), provide therapy after checking dose. When we check dose distribution, F/S systems have radiation signal distortion because there is low resolution by penumbra depending on the condition of film developed. In this study, We fabricated a $HgI_2$ Semiconductor radiation sensor for base study in order that we verify the real dose distribution weather it's same as plans or not in brachytherapy. Also, we attempt to evaluate the feasibility of QA system by utilizing and evaluating the sensor to brachytherapy source. As shown in the result of detected signal with various source-to-detector distance (SDD), we quantitatively verified the real range of treatment which is also equivalent to treatment plans because only the low signal estimated as scatters was measured beyond the range of treatment. And the result of experiment that we access reproducibility on the same condition of ${\gamma}$-ray, we have made sure that the CV (coefficient of variation) is within 1.5 percent so we consider that the $HgI_2$ sensor is available at QA of brachytherapy based on the result.