• Journal of the Korean Society of Hazard Mitigation
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• v.8 no.4
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• pp.123-133
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• 2008

This study evaluated the runoff data collected at 12 stream gauge stations of the Chungjoo dam basin using the IHACRES model. Especially, the geomorphology-related parameters of the IHACRES model could be quantified base on the regionalization technique, which have also been applied many stream gauge stations of the Chungjoo dam basin. Summarizing the results is as follows. (1) The climate-related parameters of the IHACRES model c, $\tau_w{^0}$, and f are found to be estimated and used uniformly over the basin. (2) The geomorphology-related parameters of the IHACRES model $t_q,\;t_s,\;and\;v_s$ are found to be estimated by considering the geomorphological parameters like the basin area, channel length, channel slope, basin slope through the regionalization based on the regression analysis. (3) Using the climate-related parameters applied uniformly over the basin and the geomorphology-related parameters estimated based on the regionalization procedure for each stream gauge station, a total of 12 stream gauge stations have been evaluated with their stream flow measurements. As results, the Sanganmi and Youngwal 1 stream gauge stations have been found to make high quality flow data, but Youngwal, Baekokpo, and Panwoon stations low quality flow data. On the whole, 12 stream gauge stations considered show large differences with their data quality, so a plan for securing more consistent data quality should be prepared imminently.

• Journal of Wetlands Research
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• v.19 no.4
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• pp.470-483
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• 2017

Changes in land cover or land use, such as changes in forest area, can cause changes in water and energy circulation, ultimately affecting overall hydrological cycle including stream flow, evapotranspiration, soil moisture, and base flow. In this study, the changes of the hydrological processes over the past long period were simulated by using large-scale surface hydrologic model along with various soil, land use, vegetation, and meteorological data. For this purpose, this study simulated and evaluated the changes in the hydrological cycle for the past 50 years (1955-2010) in East Asia including China, Japan and South Korea. In particular, this study used the land cover maps which can properly reflect the vegetation condition for each simulation period. As results, the mean runoff ratio of China was estimated to be 47.0% over the entiree period, 62.7% in Japan and 49.4% in South Korea. The mean soil moisture of China was estimated to be 22.2%, 35.6% in Japan and 23.9% in South Korea. Finally, the mean evapotranspiration rate was estimated to be 52.7% in China, 37.3% in Japan and 50.4% in South Korea. Especially, in China, the hydrological cycle was found to be changed very much for the entire simulation period. However, in Japan, the hydrological cycle was found to be very stable for the entire simulation period. The hydrological cycle was also found to become stable mainly due to the stabilization of the vegetation.

• Journal of Chest Surgery
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• v.37 no.4
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• pp.342-348
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• 2004

It is very important for hemodialysis in patients with end stage renal disease to obtain vascular access that resists repeated punctures and maintains adequate blood flow. This study was designed to indentify factors that may influence early patency rate of autogenous arteriovenous fistula. Material and Method: 49 cases in 47 patients who underwent radiocephalic fistula formation in our hospital from June 2002 through May 2003 were reviewed and analyzed. Result: The early patency rate was 79.6%. Age, sex, hypertension, and diabetes mellitus were not significant factors for patency. Body mass index and duration of hypertension and diabetes did not influence the early results either. Cephalic vein diameter measured preoperatively and blood flow at radio-cephalic fistula were significantly positive correlative factors. Groups with the vein diameter less than 2.7mm, or with the blood flow less than 100 mL/min had significantly lower early patency rate than the other groups. Conclusion: To improve early patency rate of radiocephalic fistula, large sized cephalic vein should be selected and if the intraoperative flow at radiocephalic fistula is less than 100 mL/min, another arteriovenous fistula formation should be considered.

• Journal of the Korean earth science society
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• v.21 no.2
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• pp.128-136
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• 2000

To understand the variation and transport pattern of suspended matters, salinity, tidal current and suspended matters in semiclosed Muan Bay have been monitored during winter and summer. The suspended matters show considerably seasonal variations with low concentration and homogeneity in the water column during winter season, but with high concentration and layering during summer season. Particularly, during summer season, the freshwater and the suspended matters influxed by the gate operation of the Youngsan River sea-dike are transported northward in accordance with the would flow into the inner-bay by relaxed flood currents after the construction of sea-dike and sea-walls in the Mokpo coastal zone. But, in the south bay-mouth, those matters outflow through the bay-mouth, resulting from tidal ebb dominance and asymmetry in the west bay-mouth. The residual suspended matter flux is much higher in the south bay-mouth(-0.0955kg/m ${\cdot}$ sec) than that of west bay-mouth(0.0078kg1m ${\cdot}$ sec). Accordingly, The Muan Bay is interpreted as erosion-dominated environments, and the erosion somewhat progresses in the intertidal flat of the bay.

• Journal of Chest Surgery
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• v.35 no.11
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• pp.807-811
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• 2002

Due to its less invasive nature and superior visual field, video-assisted thoracescopic excision of mediastinal mass is thought to be comparable to open thoracotomy. Material and Method : From January 1995 to August 2001, the medical records of 38 patients who underwent video-assisted thoracoscopic excision of mediastinal mass was retrospectively analyzed. The outcome of these patients were compared with 5 patients who converted to thoracotomy Result: Male to female ratio was 13(34.2%) : 25(65.8%), and mean age was 39.2$\pm$35.4 years. Regarding the pathology, there were 8 neurilemmomas(21.1%), 6 thymic cysts (15.8%), 5 teratomas(13.2%), 5 ganglioneuromas(13.2%), 4 bronchogenic cysts(10.5%), 3 pericardial cysts(7.9%), 3 thymomas(7.9%), and 2 lymphangiomas(5.3%). The mean operation time was 110.6$\pm$7.0 minutes, mean postoperative tube stay was 4.2$\pm$0.4 days, mean postoperative hospital stay was 5.2$\pm$0.4 days, and mean number of injection of analgesics was 1.9$\pm$0.4 times. Although the mean values for the above indices were less than those of the thoracotomy conversion cases, they were statistically insignificant. Postoperative complications of videoassisted thoracoscopic excision included chylothorax, prolonged air leakage, and unilateral phrenic nerve palsy, all of which recovered before patient discharge. There was, however, permanent unilateral ptosis in one patient. Conclusion : As video-assisted thoracoscopic excision of mediastinal mass is safe, less painful, conducive to earlier recovery and cosmetically more appealing, a more active application of this technique is recommeded.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.31 no.5B
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• pp.393-403
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• 2011

This study theoretically reviewed the empirical G/R ratio by considering three regression and trend lines; the general linear regression curve, linear regression curve passing the origin, and the line passing the origin and the mass center of observed data. This review included the problem of choosing the independent variable and that of considering the zero measurements. This review result was also applied to the Typhoon Maemi in 2003 for their evaluation. Additionally, those regression and trend lines were compared using the RMSE between the corrected radar rainfall and observed rain gauge rainfall to select the most appropriate G/R ratio. Summarizing the results is as follows. First, the results of selecting the rain gauge rainfall as the independent variable were found better than the opposite case. Second, the effect of zero measurements varies depending on the structure of radar and rain gauge rainfall. Finally, the results from the comparison of three regression and trend lines shows that the slope of the regression line passing the origin with its independent variable of rain gauge rainfall would be used most appropriately for the G/R ratio, especially when the corrected radar rainfall is used for the flood analysis. The effect of zero measurements in this case was found not so significant.

• The Journal of Information Systems
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• v.27 no.1
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• pp.171-191
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• 2018

Purpose Corporate technology leakage is not only monetary loss, but also has a negative impact on the corporate image and further deteriorates sustainable growth. In particular, since SMEs are highly dependent on core technologies compared to large corporations, loss of technology leakage threatens corporate survival. Therefore, it is important for SMEs to "prevent and protect technology leakage". With the recent development of data analysis technology and the opening of public data, it has become possible to discover and proactively detect companies with a high probability of technology leakage based on actual company data. In this study, we try to construct profiles of enterprises with and without technology leakage experience through profiling analysis using data mining techniques. Furthermore, based on this, we propose a classification model that distinguishes companies that are likely to leak technology. Design/methodology/approach This study tries to develop the empirical model for prevention and protection of technology leakage through profiling method which analyzes each SME from the viewpoint of individual. Based on the previous research, we tried to classify many characteristics of SMEs into six categories and to identify the factors influencing the technology leakage of SMEs from the enterprise point of view. Specifically, we divided the 29 SME characteristics into the following six categories: 'firm characteristics', 'organizational characteristics', 'technical characteristics', 'relational characteristics', 'financial characteristics', and 'enterprise core competencies'. Each characteristic was extracted from the questionnaire data of 'Survey of Small and Medium Enterprises Technology' carried out annually by the Government of the Republic of Korea. Since the number of SMEs with experience of technology leakage in questionnaire data was significantly smaller than the other, we made a 1: 1 correspondence with each sample through mixed sampling. We conducted profiling of companies with and without technology leakage experience using decision-tree technique for research data, and derived meaningful variables that can distinguish the two. Then, empirical model for prevention and protection of technology leakage was developed through discriminant analysis and logistic regression analysis. Findings Profiling analysis shows that technology novelty, enterprise technology group, number of intellectual property registrations, product life cycle, technology development infrastructure level(absence of dedicated organization), enterprise core competency(design) and enterprise core competency(process design) help us find SME's technology leakage. We developed the two empirical model for prevention and protection of technology leakage in SMEs using discriminant analysis and logistic regression analysis, and each hit ratio is 65%(discriminant analysis) and 67%(logistic regression analysis).

• Journal of the Mineralogical Society of Korea
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• v.19 no.4 s.50
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• pp.291-300
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• 2006

This study has been carried out to reveal the mineralogical compositions, the concentrations of heavy metals, and related factors in the sediments of the Kumho River which is the main tributary of the Nakdong River. Even though this river flows in a short distance, it runs through different geology and industrial areas and can be a good candidate to study different geological and anthropogenic factors affecting the concentrations of heavy metals in the sediment. The major rock-forming minerals were quartz and albite. Minor amount of orthoclase, microcline, and amphybole were also identified. Clay minerals including illite, chlorite, kaolinite were associated with those minerals. In the downstream, no noticeable changes in species and amount of minerals were observed, indicating there is almost no influence on the mineralogical compositions from rock types. The concentrations of heavy metals in the sediments are in the order of Zn > Pb > Cu > Ni > Cr > Co > Cd. Following the downstream, the concentrations of heavy metals generally increase, except Pb. The regional increase of the heavy metal content is well correlated with the location of the tributary. Without changes in mineral compositions, the main factors controlling the heavy metal contents are the locations of pollutant sources. Except Pb and Ni, most of the concentrations of heavy metals were thought to be enriched by the past pollutant sources.

• Journal of the Korean association of regional geographers
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• v.16 no.4
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• pp.369-386
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• 2010

Migration usually derived from the gap of spatial efficiency and the attractiveness difference between the origin and the destination puts forth significant impact on the regional dynamics of population. Both migration and regional planning or policy are structurally interconnected, exerting impact each other within the circular loops. In order to observe migration characters in the regional dimension, this research depends on social network analysis(SNA) methods which easily portray interrelationship and its weight between the origin and the destination. In specific, it focuses on the application of centrality indicators in order to understand the in- and out-migration patterns and visualize them with spring graphs, pinpointing the in- and out-migration administrative units. This research deals with three migration patterns in 2001 and 2008, respectively: i) in- and out-migration between the nation and Chungbuk Province; ii) in- and out-migration within Chungcheong Areas; and iii) in- and out-migration within Chungbuk Province. Judging from Chungbuk examples, the highest in-migration was recorded at Heungduck District in terms of in- and out-migration between the nation and Chungbuk Province. Seoul and Gyeonggi were two major origins towards Chungbuk Province. Within Chungcheong Areas, Daejeon produced the highest in-migration in 2001. However, Chungnam took that position in 2008.

• Informatization Policy
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• v.27 no.1
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• pp.72-91
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• 2020

In this study, we classified SNS into open and closed types, and empirically examined in which SNS activity the privacy paradox holds. The idea comes from the argument that privacy paradox may be observed differently in the open SNS, which is more vulnerable to the leakage of personal information due to public profiles, and the closed SNS, which is relatively less vulnerable by limiting the range of acquaintances, The results of the empirical analysis are as follows. First, in case of SNS usage, the privacy paradox holds in the overall SNS activities, but different conclusions are drawn according to open and closed SNS. In particular, it is found that as privacy concerns increase, individuals respond in a reasonable and desirable way to reduce SNS activity in the open SNS, which is more susceptible to infringement. Second, in the case of SNS activity intensity, (i) heavy users are more seriously aware of the probability of privacy infringement than light users, so there is a reasonable response to reducing the intensive margin with increasing privacy concerns, and (ii) this tendency is more clearly observed in open SNS, which is more vulnerable to privacy infringement. Accordingly, insisting that the privacy paradox is empirically established by observing only the overall SNS activities without distinguishing them into open and closed SNS may be interpreted as a "Fallacy of Composition."