• Economic and Environmental Geology
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• v.34 no.5
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• pp.485-498
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• 2001

This study was objected to identify the temporal and spatial variations oi groundwater quality and contamination using monthly groundwater monitoring data collected from 30 wells in Daejung watershed, Jeju Island. Water samples were analyzed for major cations. anions, and environmental isotopes including $^{18}0-H_2$O,$^{2}H-H_2$O and$^{15}$ N-NO$_3$The groundwater represented mostly Na(Mg)-HCO$_3$ type, with local change toward Ca-HCO$_3$ type and Na-Cl type. Groundwater quality depends upon various factors such as the local groundwater flowpaths, input of surface contaminants with recharge events, and sea-water intrusion along the coastal area. Nitrate contamination changed temporally according to recharge events and spatially. $\delta$$^{18}$ O-$\delta$$_2$H data for monthly sampled groundwaters showed distinctive clusters, implying that groundwater was originated from independent precipitation, and subsequently recharged very fash. Using$\delta$$^{15}$ N-NO$_3$ data, major sources of nitrate and its areas of influence could be identified. The areas under influence of livestock farms showed relatively high NO$_3$-N concentrations and$\delta$$^{15}$ N values higher than 5$\textperthousand$. The agricultural areas in southeastern part showed very high concentrations of NO$_3$-N with the $\delta$$^{15}$ N values of lower than 5$\textperthousand$.

• Archives of Plastic Surgery
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• v.38 no.6
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• pp.894-898
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• 2011

Purpose: Coverage of full-thickness large flank defect is a challenging procedure for plastic surgeons. Some authors have reported external oblique turnover muscle flap with skin grafting, inferiorly based rectus abdominis musculocutaneous flap, and two independent pedicled perforator flaps for flank reconstruction. But these flaps can cover only certain portions of the flank and may not be helpful for larger or more lateral defects. We report a case of large flank defect after resection of extraskeletal Ewing's sarcoma which is successfully reconstructed with reverse latissimus dorsi myocutaneous flap. Methods: A 24-year-old male patient had $13.0{\times}7.0{\times}14.0$ cm sized Ewing's sarcoma on his right flank area. Department of chest surgery and general surgery operation team resected the mass with 5.0 cm safety margin. Tenth, eleventh and twelfth ribs, latissimus dorsi muscle, internal and external oblique muscles and peritoneum were partially resected. The peritoneal defect was repaired with double layer of Prolene mesh by general surgeons. $24{\times}25$ cm sized soft tissue defect was noted and the authors designed reverse latissimus dorsi myocutaneous flap with $21{\times}10$ cm sized skin island on right back area. To achieve sufficient arc of rotation, the cephalic border of the origin of latissimus dorsi muscle was divided, and during this procedure, ninth intercostal vessels were also divided. The thoracodorsal vessels were ligated for 15 minutes before divided to validate sufficient vascular supply of the flap by intercostal arteries. Results: Mild congestion was found on distal portion of the skin island on the next day of operation but improved in two days with conservative management. Stitches were removed in postoperative 3 weeks. The flap was totally viable. Conclusion: The authors reconstructed large soft tissue defect on right flank area successfully with reverse latissimus dorsi myocutaneous flap even though ninth intercostal vessel that partially nourishes the flap was divided. The reverse latissimus dorsi myocutaneous flap can be used for coverage of large soft tissue defects on flank area as well as lower back area.

• Journal of the korean society of oceanography
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• v.39 no.1
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• pp.57-71
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• 2004

Based on the data obtained under the China-Korea joint project (1997-2001) and historic observations, the distribution, transportation and sedimentation of sediment in the southern Yellow Sea (SYS) are discussed, and the controversial formation mechanism of muddy sediments is also explored. The sediment transport trend analysis indicates that the net transport direction of sediment in the central SYS (a fine-grained sediment deposited area) points to $123.4^{\circ}E,\;35.1^{\circ}N$, which is a possible sedimentation center in the central SYS. The sediment transport pattern is verified by the distribution of total suspended matter (TSM) concentration and ${\delta}^{13}C$ values of particulate organic carbon (POC), the latter indicates that the bottom water plays a more important role than the surface water in transporting the terrigenous material to the central deep-water area of the SYS, and the Yellow Sea circulation is an important control factor for the sediment transport pattern in the SYS. The carbon isotope signals of organic matter in sediments indicate that the Shandong subaqueous delta has high sedimentation rate and the deposited sediments originate mainly from the modern Yellow River. The terrigenous sediments in deep-water area of the SYS originate mainly from the old Yellow River and the modern Yellow River, and only a small portion originates from the modern Yangtze River. The analytical results of TSM and stable carbon isotopes are further confirmed by another independent tracer of sediment source, polycyclic aromatic hydrocarbons (PAHs). Five light mineral provinces in the SYS can be identified and they indicate inhomogeneity in sources and sedimentary environment. The modern shelf sedimentary processes in the SYS are controlled by shelf dynamic factors. The muddy depositional systems are produced in the shelf low-energy environments, which are controlled by some meso-scale cyclonic eddies (cold eddies) in the central SYS and the area southwest of the Cheju Island. On the contrary, an anticyclonic muddy depositional system (warm eddy sediment) appears in the southeast of the SYS (the area northwest of the Cheju Island). In this study, we give the cyclonic and anticyclonic eddy sedimentation patterns.

• Journal of the Korean Society of Groundwater Environment
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• v.5 no.2
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• pp.66-79
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• 1998

This study purposes to elucidate the characteristics of local water quality and the evolutional process of the spring water have been studied with the samples from 55 selected springs, from the coast region to the Baegrogdam, a caldera lake of Halla mountain in Cheju Island. Results of hydrochemical analyses in the 55 spring water show that Gwaneumsa is pollued with high hydrogen concentration, and spring waters from Yusuarmchun, Jangsumul, Dukjisemmul, Sinch'onk'nmul, Youngchunsa, Woonyangchun, Harwontongmul, Dongheamul, Seakdalsengsu, Andukkyekok, Dotimul, Kinmul, Harkangmul and Jungkeummul are polluted by the pollution sources from the surface surrounding ground. Spring waters of Samyang3suwon, Meungbusa, Sernurungmul, Tosanmul, Jungkeummul, Kwakgimul, Aewolharmul, Konemul and Nokgomul are also polluted from the sea water intrusion. The electrical conductivity, pH and the concentration of nitrate nitrogen and bicarbonate increase when the precipitation increases, but the concentration of sodium, chloride and sulphate decrease when the precipitation increases. The concentrations of potassium, magnessium and calcium are nearly independent of the precipitaion. Quality characteristics of spring water show complicated group of spring water through piper's trilinear diagram. The high mountain region consists of groups of sodium or potassium type and bicarbonate type; the middle mountain region consists of groups of sodium or potassium type and no dominant type; the low mountain consists of groups of no dominant type and sulfate or nitrate type; the coast region consists of groups of sodium or potassium type and chloride type or no dominant type. These characteristics indicate that the spring waters are changed from bicarbonate type in the high and middle mountain regions into non-bicarbonate type in the coastal region, as the precipitated waters flow downslope.

• Journal of the Korean Society for Marine Environment & Energy
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• v.17 no.3
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• pp.224-235
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• 2014

Changes in the interactions among incident ocean water waves, coastal debris (marine debris), and the back vegetation zone line on a natural sandy beach on the island of Jinu-do in the Nakdong river estuary were investigated. The study involved a cross-sectional field survey of the beach, numerical modeling of incident ocean water waves, field observations of the distribution of coastal debris, and vegetation zone line tracking using GPS. The conclusions of this study can be summarized as follows: (1) The ground level of the swash zone (sandy beach) on Jinu-do is rising, and the vegetation zone line, which is the boundary of the coastal sand dunes, shows a tendency to move forward toward the open sea. The vegetation zone line is developing particularly strongly in the offshore direction in areas where the ground level is elevated by more than 1.5 m. (2) The spatial distributions of incident waves differed due to variations in the water depth at the front of the beach, and the wave run-up in the swash zone also displayed complex spatial variations. With a large wave run-up, coastal debris may reach the vegetation zone line, but if the run-up is smaller, coastal debris is more likely to deposit in the form of an independent island on the beach. The deposited coastal debris can then become a factor determining which vegetation zone line advances or retreats. Finally, based on the results of this investigation, a schematic concept of the mechanisms of interaction between the coastal debris and the coastal vegetation zone line due to wave action was derived.

• Journal of Biosystems Engineering
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• v.43 no.3
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• pp.247-254
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• 2018

Purpose: Although previous studies have performed on-farm evaluations for the control of airborne diseases such as foot-and-mouth disease (FMD) and influenza, disease control during the process of livestock and manure transportation has not been investigated thoroughly. The objective of this study is to predict common patterns of livestock-vehicle movement. Methods: Global positioning system (GPS) data collected during 2012 and 2013 from livestock vehicles on Jeju Island, South Korea, were analyzed. The GPS data included the coordinates of moving vehicles according to the time and date as well as the locations of livestock farms and manure-keeping sites. Data from 2012 were added to Esri software ArcGIS 10.1 and two approaches were adopted for predicting common vehicle-movement patterns, i.e., point-density and Euclidean-distance tools. To compare the predicted patterns with actual patterns for 2013, the same analysis was performed on the actual data. Results: When the manure-keeping sites and livestock farms were the same in both years, the common patterns of 2012 and 2013 were similar; however, differences arose in the patterns when these sites were changed. By using the point-density tool and Euclidean-distance tool, the average similarity between the predicted and actual common patterns for the three vehicles was 80% and 72%, respectively. Conclusions: From this analysis, we can determine common patterns of livestock vehicles using previous year's data. In the future, to obtain more accurate results and to devise a model for predicting patterns of vehicle movement, more dependent and independent variables will be considered.

• Korean Journal of Ecology and Environment
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• v.48 no.1
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• pp.68-76
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• 2015

There is no willow riparian vegetation in Jeju Island, Korea. Instead, a genetically-isolated population of Adina rubella is found in some parts of the riparian system. We describe its syntaxonomy and synecology. A total of 27 phytosociological relev$\acute{e}$s were collected, 11 relev$\acute{e}$s from 91 sites and 16 relev$\acute{e}$s from the previously published relevant materials. Data were analyzed by traditional Braun-Blanquet method and multivariate PCoA (Principal coordinates analysis). New syntaxa are distinguished, Adinion rubellae all. nov. and its type association Tripogono-Adinetum rubellae ass. nov. with two subassociations, typicum and rhododendretosum poukhanensae. Adino-Rhododendretum poukhanensae Itow et al. 1993 was discarded owing to mismatch of syntaxonomy and syngeography of Adina and Rhododendron phytocoena. The alliance Adinion is Jeju's regional and partly ombrotrophic vegetation occurring in pothole and rock crevice where are independent on ground-water table. We also suggest a revised alliance, Rhododendrion poukhanensae Lee 2004 ex. hoc loco in Korean peninsula, as a corresponding syntaxon to Adinion, which completely differs from Phragmito-Salicion. Finally we pointed out that Adina phytocoena requiring an absolutely monitoring has been threatened by river maintenance project of local government.

• Molecules and Cells
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• v.40 no.5
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• pp.346-354
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• 2017

Long interspersed nuclear element-1 (LINE-1) is a retrotransposon that contains a CpG island in its 5'-untranslated region. The CpG island of LINE-1 is often heavily methylated in normal somatic cells, which is associated with poor prognosis in various cancers. DNA methylation can differ between formalin-fixed paraffin-embedded (FFPE) and frozen tissues. Therefore, this study aimed to compare the LINE-1 methylation status between the two tissue-storage conditions in gastric cancer (GC) clinical samples and to evaluate whether LINE-1 can be used as an independent prognostic marker for each tissue-storage type. We analyzed four CpG sites of LINE-1 and examined the methylation levels at these sites in 25 FFPE and 41 frozen GC tissues by quantitative bisulfite pyrosequencing. The LINE-1 methylation status was significantly different between the FFPE and frozen GC tissues (p < 0.001). We further analyzed the clinicopathological features in the two groups separately. In the frozen GC tissues, LINE-1 was significantly hypomethylated in GC tissues compared to their corresponding normal gastric mucosa tissues (p < 0.001), and its methylation status was associated with gender, differentiation state, and lymphatic and venous invasion of GC. In the FFPE GC tissues, the methylation levels of LINE-1 differed according to tumor location and venous invasion of GC. In conclusion, LINE-1 can be used as a useful methylation marker for venous invasion in both FFPE and frozen tumor tissues of GC.

• Korea Trade Review
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• v.45 no.4
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• pp.137-152
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• 2020

The increase in national income, the expansion of transportation network, the increase in leisure time, and the influx of foreign tourists in the era of internationalization, the influx of the outside population of Jeju region increased rapidly until 2020. However, the corona 19 (Covid-19) incident that began in January 2020 has hit the entire industry, and the tourism industry in Jeju has also been greatly damaged. However, in the second half of 2020, with some calming of the Corona 19 situation and difficult to leave overseas, the number of visitors to Jeju Island is increasing again as Koreans choose Jeju Island as their domestic tourism. This study analyzed the capacity of Jeju's external population based on the Contingent Valuation Method, and based on this, attempted to suggest policy recommendations for Jeju. The size of accommodations such as the density of visitors, toilets, and rest areas were excluded from consideration, and the level of securing the parking lot already exceeded the capacity, and the rate of securing the parking lot was 93.4%. In the case of accommodation, the total number of available rooms is 88,691, even if one guest per room is assumed, which is 32,372,215 per year, which is sufficient in terms of visitor capacity. To analyze the aspects of psychological capacity, this study analyzed whether the residents are feeling psychological discomfort through three methods of road congestion, garbage disposal, and sewage treatment through Contingent Valuation Method. However, the inconvenience caused by the increase of visitors and the effect of continuous population influx is working in combination, and it has the limitation that the effects of these independent factors cannot be specifically separated. As a result of the study, discomfort has already been recognized in terms of psychological capacity among the factors of capacity, and it was estimated that a cost of about 45 billion won per year was incurred as a result of deriving psychological costs through Contingent Valuation Method. In the future, a policy review is needed to resolve or maintain the perception of this discomfort through continuous management. Accordingly, it is necessary to recognize that the increase of visitors leads to the psychological discomfort of the residents, and to seek a policy alternative that can simultaneously increase the number of visitors and the comfort of the residence.

• Korean Journal of Microbiology
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• v.51 no.4
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• pp.398-406
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• 2015

Culture-dependent ARDRA and culture-independent DGGE were employed to investigate the bacterial community associated with the marine sponge Halichondria panicea collected from Jeju Island. A total of 120 bacterial strains associated with the sponge were cultivated using modified Zobell and Marine agar media. PCR amplicons of the 16S rRNA gene from the bacterial strains were digested with the restriction enzymes HaeIII and MspI, and then assigned into different groups according to their restriction patterns. The 16S rRNA gene sequences derived from ARDRA patterns showed more than 96% similarities compared with known bacterial species, and the isolates belonged to four classes, Alphaproteobacteria, Gammaproteobacteria, Bacteroidetes, and Firmicutes, of which Alphaproteobacteria was dominant. DGGE fingerprinting of 16S rRNA genes amplified from the sponge-derived total gDNA showed 14 DGGE bands, and their sequences showed 100% similarities compared with the sequences available in GenBank. The sequences derived from DGGE bands revealed high similarity with the uncultured bacterial clones. DGGE revealed that bacterial community consisted of seven classes, including Alphaproteobacteria, Gammaproteobacteria, Acidobacteria, Actinobacteira, Bacteroidetes, Cyanobacteria, and Chloroflexi. According to both the ARDRA and DGGE methods, three classes, Alphaproteobacteria, Gammaproteobacteria, and Bacteroidetes, were commonly found in H. panicea. However, overall bacterial community in the sponge differed depending on the analysis methods. Sponge showed more various bacterial community structures in culture independent method than in culture-dependent method.