• Economic and Environmental Geology
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• v.31 no.3
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• pp.185-199
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• 1998

Hydrogeochemical and environmental isotope studies were undertaken for various kinds of water samples collected in 1995-1996 from the Bugok geothermal area. Physicochemical data indicate the occurrence of three distinct groups of natural water: Group I ($Na-S0_4$ type water with high temperatures up to $77^{\circ}C$, occurring from the central part of the geothermal area), Group II (warm $Na-HCO_{3}-SO_{4}$ type water, occurring from peripheral sites), Group III ($Ca-HCO_3$ type water, occurring as surface waters and/or shallow cold groundwaters). The Group I waters are further divided into two SUbtypes: Subgroup Ia and Subgroup lb. The general order of increasing degrees of hydrogeochemical evolution (due to the degrees of water-rock interaction) is: Group III$\rightarrow$Group II$\rightarrow$Group I. The Group II and III waters show smaller degrees of interaction with rocks (largely calcite and Na-plagioclase), whereas the Group I waters record the stronger interaction with plagioclase, K-feldspar, mica, chlorite and pyrite. The concentration and sulfur isotope composition of dissolved sulfate appear as a key parameter to understand the origin and evolution of geothermal waters. The sulfate was derived not only from oxidation of sedimentary pyrites in surrounding rocks (especially for the Subgroup Ib waters) but also from magmatic hydrothermal pyrites occurring in restricted fracture channels which extend down to a deep geothermal reservoir (typically for the Subgroup Ia waters). It is shown that the applicability of alkaliion geothermometer calculations for these waters is hampered by several processes (especially the mixing with Mg-rich near-surface waters) that modify the chemical composition. However, the multi-component mineral/water equilibria calculation and available fluid inclusion data indicate that geothermal waters of the Bugok area reach temperatures around $125^{\circ}C$ at deep geothermal reservoir (possibly a cooling pluton). Environmental isotope data (oxygen-18, deuterium and tritium) indicate the origin of all groups of waters from diverse meteoric waters. The Subgroup Ia waters are typically lower in O-H isotope values and tritium content, indicating their derivation from distinct meteoric waters. Combined with tritium isotope data, the Subgroup Ia waters likely represent the older (at least 45 years old) meteoric waters circuated down to the deep geothermal reservoir and record the lesser degrees of mixing with near-surface waters. We propose a model for the genesis and evolution of sulfate-rich geothermal waters.

• Korea Trade Review
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• v.43 no.4
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• pp.177-217
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• 2018

The purpose of this study is to classify the types of internationalization strategies utilized by Korean ventures and to examine whether there is a significant relationship between these types and internationalization performances. Specifically we tested whether there is a good feasibility through empirical analysis of the study model constructed through the following process. As a criterion of typification, the capability of international entrepreneurship and the capability of effectuation of a venture were chosen, and a model in which those three types exist based on the capabilities is established. The characteristics of each type and the contents of internationalization strategy are explained and empirical analysis is conducted. We also test whether there are significant differences in internationalization performance for each type. As a result of the cluster analysis, we concluded that there are three types : pioneer, careful preparation and passive response. In addition, these three types have significant differences in the levels of performances of reputation in foreign markets and the accumulation of knowledge in international management. This implies significant differences among the performances of each type of ventures according to their internationalization strategy positions. Therefore, the type of venture should be considered when a venture establishes its internationalization strategy and governments set supporting policy for venture companies.

• Journal of the Korean Data and Information Science Society
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• v.28 no.2
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• pp.395-406
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• 2017

The purpose of this study is to identify the pattern of daily electricity demand through clustering and classification. The hourly data was collected by KPS (Korea Power Exchange) between 2008 and 2012. The time trend was eliminated for conducting the pattern of daily electricity demand because electricity demand data is times series data. We have considered k-means clustering, Gaussian mixture model clustering, and functional clustering in order to find the optimal clustering method. The classification analysis was conducted to understand the relationship between external factors, day of the week, holiday, and weather. Data was divided into training data and test data. Training data consisted of external factors and clustered number between 2008 and 2011. Test data was daily data of external factors in 2012. Decision tree, random forest, Support vector machine, and Naive Bayes were used. As a result, Gaussian model based clustering and random forest showed the best prediction performance when the number of cluster was 8.

• Journal of The Korea Institute of Healthcare Architecture
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• v.28 no.1
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• pp.63-74
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• 2022

Purpose: The purpose of this study is to present an evacuation performance analysis model that can derive vulnerable evacuation spaces with considering the movement behavior as per the elderly groups in the event of a fire in a geriatric hospital. Methods: The evacuation characteristics of geriatric hospital users were investigated through the review of precedent studies. First, the occupant conditions and the evacuation scenario were set to analyze a study target hospital. Then, the evacuation simulation was carried out considering the group types and the density of each group. Finally, an evacuation performance analysis model according to the group type was presented based on the simulation results. Results: The results of this study are as follows: (1) The evacuation performance according to the group type is to be clarified through the suggested study model. (2) It is necessary to secure a ramp or an emergency elevator to distribute the evacuation personnel at the design stage because congestion occurs due to collisions between evacuees on the stairs and delays the evacuation time. (3) It is necessary to consider the evacuation stairs and openings of sufficient size by analyzing the frequency of congestion occurrence and the escape routes of occupants in advance to identify the space where the evacuation flow overlaps. Implications: It is expected that the study result is to be used as primary data for studies that consider the elderly and clustering evacuation behavior in the event of a fire in a geriatric hospital.

• The Journal of the Korea Contents Association
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• v.12 no.4
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• pp.457-467
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• 2012

The purpose of the study was to explore the general characteristics of sports for all through the patterns of sports for all policy and analysis of causal relation of the determinants. To achieve this goal, 26 countries among OECD 30 members which provide useful data sources were selected. The data were analyzed by Qualitative Comparative Analysis(QCA) with cluster analysis. GDP, leisure time, social expenditure, Gini's coefficient, poverty rate and tax burden ratio were used as casual variables for Qualitative Comparative Analysis. The findings of this study were as follows. First, three patterns were examined and Korea was classified into the pattern which has low sports for all participation and sportsclub participation. Second, as a result of Qualitative Comparative Analysis for analyzing the determinants of sports for all patterns, the pattern in which includes Korea showed that GDP, leisure time, social expenditure, tax burden ratio had negative relationship and Gini's coefficient, poverty rate had positive relationship.

• Korean Journal of Environment and Ecology
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• v.26 no.6
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• pp.884-891
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• 2012

The characteristic of fish fauna and distribution by habitat type in the Yanghwa stream were investigated from August, 2008 to June, 2009. During the surveyed period, 30 species belonging 8 families were collected. And there were 10 Korea endemic species(33.3%), including Rhodeus uyekii et and so on. Dominant species was Rhodeus notatus, and subdominant species was Pseudorasbora parva. Dominant species according to habitat type was Pseudorasbora parva in Dam type pool and Channel conected pool, Pseudogobio esocinus(Run), Zacco platypus(Riffle), Rhodeus notatus(Side channel and Substrate type pool), Squalidus gracilis majimae(Meander type pool), and Carassius auratus(Channel unconnected pool), respectively. As a results of community analysis in the Yanghwa Stream, diversity, richness, and abundance indices showed relatively high values, indicating that studied stream have relatively stable community structure. Moreover, cluster and principal component analysis were divided by two groups(lotic and lentic habitats), suggest that species and individuals were different among habitat types.

• Proceedings of the KAIS Fall Conference
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• 2010.11b
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• pp.651-654
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• 2010

본 연구는 국내사업체 수에서 87.9% 이상을 차지하고 있는 소상공인들의 창업과 경영애로 분야에서 가장 시너지효과가 크다고 보여지는 소상공인 조직화부분에 대하여 실증적 연구를 실시하였다. 본연구은 소상공인 조직화를 위하여 소상공인 조직화를 프랜차이즈, 공동브랜드, 업종별 협회, 시 군 구에 등록된 상인회로 구분하였다. 소상공인들의 내적인 면에서 경영전략 선정에 있어서 어떠한 가치관을 가지는 지에 대하여 국내 최초로 군집분석에 의한 실증적인 분석을 시도하였다. 연구결과 소상공인의 인구통계적인 유형에서 성별, 학력, 연령, 업종별로 유의한 조직화 인지와 조직화 효과 그리고 최종적인 경영성과에 차이가 있음을 밝혀냈다. 또한 소상공인들이 경영전략 가치관에 대하여 군집분석을 실시한 결과 가격경쟁지향과 마케팅경쟁지향, 무개념 경영등 3가지 유형의 프로파일을 도출할 수 있었다. 이러한 소상공인 조직화에 대한 프로파일 도출과 조직화 인식도에 따른 경영 성공과 실패의 상호관계에 대한 연구 결과가 의미하는 바는, 향후 정부에서는 소상공인에 대하여 시설 개선과 현대화 사업 추진 못지않게 조직화 개발과 같은 조직관리에 대한 경영현대화 사업에 더욱 많은 노력을 경주하여야 하는 필요성을 밝혀 주었다.

• Journal of Wetlands Research
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• v.18 no.4
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• pp.331-341
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• 2016

A small irrigation pond for a rice paddy field is a very important refuge for aquatic insects and plants. To reveal environmental factors determining species composition of aquatic insect and plant communities, we analyzed water chemistry and connection between pond and surrounding in five types of irrigation ponds based on water source and connection in CCZ of South Korea: stagnation, exchange-stagnation, spring, stagnation-spring, and exchange-spring types. The stagnation type had the most stable water chemistry among the 16 irrigation ponds studied, and the spring type had the most variable water chemistry. Anion content was highest in the stagnation type, and cation content was highest in the exchange-stagnation type. 228 taxa including 63 wetland plants and 95 aquatic insect taxa were recorded. Six rare plant species and four rare aquatic insect species were identified. The stagnation-spring type had the highest species richness. There was no correlation between size and species richness. Multivariate analyses showed distinctive species assemblages among the irrigation pond types. This would indicate that water chemical change at annual cycle and connection influenced on the species assemblages in irrigation pond. In additional, irrigation pond contributes to regional biodiversity in agricultural areas, as irrigation pond provides heterogeneous communities for the freshwater ecosystem.

• Journal of the Korean Institute of Landscape Architecture
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• v.37 no.4
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• pp.42-51
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• 2009

The purpose of this study is to analyze the actual conditions of school forests using a field survey and to establish the construction methods considering satisfactions of students using a satisfaction inquiry. The results of the this study are as follows: many trees had the highest score whereas reduction of noise had the lowest score in the satisfaction analysis of 15 items. According to the result of the factor analysis, 3 factors were determined to be most important from 15 items of satisfaction, and they were Environmental Function, Educational and Recreational Function, and Ecological Function. Next, students were classified into 4 groups using factor scores by cluster analysis. Group I had very high effectiveness in the Environmental Function and group II had low effectiveness in all factors. Also, group III had very high effectiveness in the Educational and Recreational Function, and group IV had very high effectiveness in the Ecological Function. According to the analysis results of the character of the school on students' group, the satisfaction of school forests was high when students of group II were few and other group's students were similar. As these schools use a lot of parts of the playground for green space, there was more school forest than at other schools. Also, students of these schools were experiencing the school forest through educational programs. Therefore, school forests should be constructed by increasing the green area and considering the satisfaction factors of students through various experience and education programs and by the way utilizing wide space than adding the tree in the garden.

• Journal of Environmental Impact Assessment
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• v.25 no.4
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• pp.296-306
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• 2016

There is a growing interest in establishing a regional climate change adaptation policy as the climate change impact in the region and local scale increases. This study focused on the analysis of 32 regions on its characteristics of local climate change adaptation plans. First, statistic program R was used for conducting cluster analysis based on the frequency and budgets of adaptation plan. Further, we analyzed damage frequency from newspapers regarding climate change impacts in eight categories which were caused by extreme weather events on 2,565 cases for 24 years. Lastly, the characteristics of climate change adaptation plan was compared with damage frequency patterns for evaluating the adequacy of climate change adaptation plan on each cluster. Four different clusters were created by cluster analysis. Most clusters clearly have their own characteristics on certain sectors. There was a high frequency of damage in 'disaster' and 'health' sectors. Climate change adaptation plan and budget also invested a lot on those sectors. However, when comparing the relative rate among regional governments, there was a difference between types of damage and climate change adaptation plan. We assumed that the difference could come from that each region established their adaptation plans based on not only the frequency of damage, but vulnerability assessment, and expert opinions as well. The result of study could contribute to policy making of climate change adaptation plan.