• Journal of radiological science and technology
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• v.32 no.1
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• pp.79-86
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• 2009

The study found out developmental factors of the liver diseases in 29, 531 cases of the healthy adults who were diagnosed by using ultrasound at domestic healthcare centers in 6 cities. The results are as follows. Based on the result of the study, the liver diseases diagnosed by using ultrasound was revealed to show 43.1% of prevalence, and the occurrence was significantly higher in male (23.3%) than in female (19.8%). The prevalence of hepatic diseases related to the BMI was revealed to show highest prevalence of the fatty liver in obese group (BMI $\geqq$ 25) by recording 44.3%. Smoking contributed to the high prevalence of all liver diseases. Although the fatty liver was the most frequently occurred form of liver diseases by recording the prevalence of 49.1% (22.2% in male, 26.9% in female), the significant difference was found only in female (p < 0.05), but male group did not show significant difference (p > 0.05). The prevalence of hepatic diseases related to the hypertension was revealed to show highest prevalence of the fatty liver in hypertension group by recording 67.7%. The prevalence of hepatic diseases related to the diabetes was revealed to show highest prevalence of the fatty liver in diabetes group by recording 66.2%. The high prevalence of all hepatic diseases was related to diabetes mellitus with statistical significance (p < 0.001). The multiple regression analysis for the related factors which affect the prevalence of the liver diseases showed the higher prevalence by age. Sex, obesity and diabetes mellitus were positively related to the prevalence (p < 0.05) while hypertension and smoking showed no significant relationship to the prevalence of the disease (p > 0.05).

• Journal of the Korean earth science society
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• v.34 no.7
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• pp.615-625
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• 2013

Many eruptions of Mt. Baekdusan volcano have been recorded in the historical literatures, and there were unrest precursors in 2002. Based on the geological survey results, it has been recognized that Mt. Baekdusan's Plinian eruptions had caused ashfall, followed by the occurrence of pyroclastic flows, which were caused by the collapse of eruption column. Therefore, we simulated the range of the impacts of pyroclastic flows, which were caused by small eruptions from a specific crater. Based on the simulation results, it can be interpreted that, when the pyroclastic flows are caused by the eruption column collapse from an eruption with less than VEI 3, the impacts will range from the outer rim of the caldera to the mountain slope 7 km at the maximum distance. Furthermore, it is interpreted that, when the eruption column occurs by the crater located inside the caldera, most will be deposited inside the caldera and what overflows will be deposited thickly mostly in the north valley, the upper stream region of Erdaobaihe.

• Korean journal of communication and information
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• v.45
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• pp.220-254
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• 2009

Presidential TV debates serve as an important instrument for the general viewers to evaluate the candidates’ character, to examine their policy, and finally to make an important political decisions to cast ballots. Every words candidates utter in the course of entire election campaign exert influence of a certain significance by delivering their ideas and by creating clashes with their respective opponents. This study focuses on the conceptual venue, coined as ‘stasis’ by ancient rhetoricians, in which the clashes take place, and examines the words selection made by each candidates, the manners in which they form stasis, call for evidence, educate the public, and finally create a legitimate form of political argumentation. The study applied computer based content analysis using KrKwic and UCINET software to analyze semantic networks among the candidates. The results showed three major candidates, namely Lee Myung Bak, Jung Dong Young, and Lee Hoi Chang, displayed separate patterns in their use of language, by selecting the words that are often neglected by their opponents. Apparently, the absence of stasis and the lack of speaking mutual language significantly undermined the effects of debates. Central questions regarding issues of North Korea failed to meet basic requirements, and the respondents failed to engage in effective argumentation process.

• The Journal of Society for e-Business Studies
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• v.23 no.2
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• pp.83-96
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• 2018

Extracting keywords representing documents is very important because it can be used for automated services such as document search, classification, recommendation system as well as quickly transmitting document information. However, when extracting keywords based on the frequency of words appearing in a web site documents and graph algorithms based on the co-occurrence of words, the problem of containing various words that are not related to the topic potentially in the web page structure, There is a difficulty in extracting the semantic keyword due to the limit of the performance of the Korean tokenizer. In this paper, we propose a method to select candidate keywords based on semantic similarity, and solve the problem that semantic keyword can not be extracted and the accuracy of Korean tokenizer analysis is poor. Finally, we use the technique of extracting final semantic keywords through filtering process to remove inconsistent keywords. Experimental results through real web pages of small business show that the performance of the proposed method is improved by 34.52% over the statistical similarity based keyword selection technique. Therefore, it is confirmed that the performance of extracting keywords from documents is improved by considering semantic similarity between words and removing inconsistent keywords.

• Korean Journal of Ecology and Environment
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• v.53 no.3
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• pp.275-285
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• 2020

Two specimens presumed to be hybrids of Rhodeus pseudosericeus and R. notatus were collected from the Sangcheon Stream of the Han River, Korea. The body color of natural hybrid individuals was yellowish brown, showing the intermediate characteristics of R. pseudosericeus and R. notatus, but overall, the characteristics of R. notatus were similar. Meristic and morphometric characters, the number of dorsal fin rays, anal fin rays and longitudinal row scales showed a hybrid index (HI) of 0, indicating the characters of R. notatus. The hybrid index of predorsal length (HI=74.6), preanal length (HI=75.3), and preventral length (HI=77.6) were similar to the characters of the R. pseudosericeus. Also four characters were appeared to have intermediate characters between R. pseudosericeus and R. notatus; number of gill rakers (HI=55.3), body depth (HI=67.9), snout length (HI=43.4), and inter orbital width (HI=44.8). The rest of 14 characters deviated between 0 and 100, showing unique characteristics of hybrid individuals. Recombination activating gene 1 (RAG1) analysis, hybrids were identified as natural hybrids due to the overlapping peaks of their parent species. Also, as a result of analysis using the cytochrome b gene (COB), one individual was derived from R. pseudosericeus, while the other was derived from R. notatus.

• Journal of environmental and Sanitary engineering
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• v.19 no.4 s.54
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• pp.9-18
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• 2004

In this study, the observation data for the yellow sandy dust phenomena from the year 1999 to 2003 at background sites in Korea were collected at Global Atmospheric Observatory at An-Myeon island and its temporal variation were analyzed. The chemical characteristics of the fine particles were also analyzed in order to evaluate sources of the yellow sandy dust particles. The results showed that the monthly average mass concentration of the fine particles was the highest in springtime and the lowest in summertime in general. The magnitude of its variation was also the highest in March in which the occurrence of yellow sandy dust was the most frequent and thus the number of samples was the largest, while the lowest in June through September. The yearly variation of ion components contributions to the total mass concentration of the fine particles was slowly decreasing, showing that $63\%$ in 1999, $59\%$ in 2000 and $56\%$ in 2003. The most prevalent ion components in the fine particles were found to be $NO_3$ and $SO_4^{2-}$, which are known to be source materials of acidic precipitation, and $NH_4^+$, a neutralizing material of the acid precipitation. Relative proportion of metal components in the fine particles was calculated as $14\%$ in average, and their concentrations are in an order of Fe > Al > Na > Ca > Zn > Pb > Cu > Mn > Ni > Cd > Cr > Co > U. The results indicated that main sources of the metals was soil-originated Fe, Al, Ca, and Mg, and the contribution of anthropogenic air Pollution-originated Zn, Pb, Cu, Mn were also high and keep slightly increasing. Statistical analysis showed that the chemical components could be divided into soil-originated group of Mg, Al, Ca, Fe, and Mn and air pollution-originated group of $NO_3$, Zn, Pb, and they are occupying more than $60\%$of all the components in the dusty sand. The results explain that An-Myeon island is more influenced by soil-originated source than ocean-originated one and also the influencing strength of anthropogenic poilution-originated source is less than $50\%$ of that of soil-originated sources. Compared to non-yellow sandy period, the yellow sandy dust period showed that the amounts of soil-originated $Mg^{2+}$ and $Ca^{2+}$ and ocean-originated $Na^+$ and $Cl^-$ were increased to more than double and the metals of Mg, Al, Ca, Fe were also highly increased, while micro metal components such as Pb, Cd, Zn, which have a tendency of concentrating in air, were either decreased or maintained at nearly constant level. In the period of yellow sandy dust, a strong positive correlation was observed between water soluble ions and between metals in terms of its concentration, respectively. Factor analysis showed that the first group being comprised of about $43\%$ of the total inorganic components was affected by soil and they are ions of $Na^+,\;Mg^{2+}\;and\;Ca^{2+}$ and metals of Na, Fe, Mn and Ni. The result also showed that the metals of Mg and Cr were classified as second group and they were also highly affected by soil sources.

• Asian Pacific Journal of Cancer Prevention
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• v.14 no.10
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• pp.6135-6140
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• 2013

Background: Breast cancer is a common malignant tumor which affects health of women and multidrug resistance (MDR) is one of the main factors leading to failure of chemotherapy. This study was conducted to establish paclitaxel-resistant breast cancer cell line and nude mice models to explore underlying mechanisms of MDR. Methods: The breast cancer drug-sensitive cell line MCF-7 (MCF-7/S) was exposed in stepwise escalating paclitaxel (TAX) to induce a resistant cell line MCF-7/TAX. Cell sensitivity to drugs and growth curves were measured by MTT assay. Changes of cell morphology and ultrastructure were examined by optical and electron microscopy. The cell cycle distribution was determined by flow cytometry. Furthermore, expression of proteins related to breast cancer occurrence and MDR was tested by immunocytochemistry. In Vivo, nude mice were injected with MCF-7/S and MCF-7/TAX cells and weights and tumor sizes were observed after paclitaxel treatment. In addition, proteins involved breast cancer and MDR were detected by immunohistochemistry. Results: Compared to MCF-7/S, MCF-7/TAX cells had a higher resistance to paclitaxel, cross-resistance and prolonged doubling time. Moreover, MCF-7/TAX showed obvious alterations of ultrastructure. Estrogen receptor (ER) expression was low in drug resistant cells and tumors while expression of human epidermal growth factor receptor 2 (HER2) and Ki-67 was up-regulated. P-glycoprotein (P-gp), lung resistance-related protein (LRP) and glutathione-S-transferase-${\pi}$ (GST-${\pi}$) involved in the MDR phenotype of resistant cells and tumors were all overexpressed. Conclusion: The underlying MDR mechanism of breast cancer may involve increased expression of P-gp, LRP and GST-${\pi}$.

• Ocean and Polar Research
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• v.37 no.2
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• pp.127-140
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• 2015

A continuous series of 60 snow samples was collected at a 2.5-cm interval from a 1.5-m snow pit at a site on the Styx Glacier Plateau in Victoria Land, Antarctica, during the 2011/2012 austral summer season. Various chemical components (${\delta}D$, ${\delta}^{18}O$, $Na^+$, $K^+$, $Mg^{2+}$, $Ca^{2+}$, $Cl^-$, $SO_4{^2-}$, $NO_3{^-}$, $F^-$, $CH_3SO_3{^-}$, $CH_3CO_2{^-}$ and $HCO_2{^-}$) were determined to understand the highly resolved seasonal variations of these species in the coastal atmosphere near the Antarctic Jang Bogo station. Based on vertical profiles of ${\delta}^{18}O$, $NO_3{^-}$and MSA, which showed prominent seasonal changes in concentrations, the snow samples were dated to cover the time period from 2009 austral winter to 2012 austral summer with a mean accumulation rate of $226kgH_2Om^{-2}yr^{-1}$. Our snow profiles show pronounced seasonal variations for all the measured chemical species with a different pattern between different species. The distinctive feature of the occurrence patterns of the seasonal variations is clearly linked to changes in the relative strength of contributions from various natural sources (sea salt spray, volcanoes, crust-derived dust, and marine biogenic activities) during different short-term periods. The results allow us to understand the transport pathways and input mechanisms for each species and provide valuable information that will be useful for investigating long-term (decades to century scale periods) climate and environmental changes that can be deduced from an ice core to be retrieved from the Styx Glacier Plateau in the near future.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.20 no.12
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• pp.44-52
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• 2019

Industrial accidents differ considerably according to the industry and the scale of these industries. These industrial disasters have been analyzed in various ways. Therefore, a technique was developed to evaluate the disaster level among companies using the ANP method and the data derived from the disaster statistics over the past five years(2013~2017), as well as the safety information characteristics through questionnaires. The objective of the study was to determine the disaster level and safety level of a company. In this paper, six factors that are considered important for assessing the disaster level of the enterprise among the disaster statistics were selected. These factors included the industry type and size, age of employee, duration of treatment, duration of employment, and typical occurrence. Most companies use the accident rate for their disaster level to compare only with other companies. In this study, the weighting factors of the company were derived taking the characteristics of each company into consideration. Therefore, the disaster level of each company can be evaluated using the disaster statistics from each company and the derived weighting factors.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.18 no.5
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• pp.471-476
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• 1985

In order to set up a predictive model for effective spat collection of Pacific oyster, Crassostrea gigas, the survival rate and time required at each developmental stage of drifting larvae were surveyed during the period from June 13 to October 16 in 1984 at the main oyster farming area, Hansan Bay, the southern part of Korea. The advent of D-shape larvae ca. $72{\times}61{\mu}m$ long had two peaks in that area : July 16 and September 20. Umbo-shape larvae ca. $189{\times}217{\mu}m$ and full grown larvae co. $303{\times}308{\mu}m$ long also showed two peaks: July 21 and September 25 for the former, and July 28 and September 30 for the latter. About five days were required for D-shape larvae to develop to umbo-shape larvae. The instantaneous death rate was 0.24 and the daily survival rate 0.78 with a mean survival rate of $29.38\%$, at this intermorphological stage. The turnover time of umbo to full grown larvae varied from five to seven days with a instantaneous death rate of 0.15, daily survival rate of 0.86 and mean survival rate of $38.54\%$. Ten to twelve days were required for each group of the D-shape larvae to reach a full grown stage, and their mean survival rate was $11.32\%$ during this developmental period.