• Journal of Korea Water Resources Association
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• v.54 no.9
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• pp.731-745
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• 2021

In this study, the monthly temperature of the Han River basin was predicted by statistical multiple regression models that use global climate indices and weather data of the target region as predictors. The optimal predictors were selected through teleconnection analysis between the monthly temperature and the preceding patterns of each climate index, and forecast models capable of predicting up to 12 months in advance were constructed by combining the selected predictors and cross-validating the past period. Fore each target month, 1000 optimized models were derived and forecast ranges were presented. As a result of analyzing the predictability of monthly temperature from January 1992 to December 2020, PBIAS was -1.4 to -0.7%, RSR was 0.15 to 0.16, NSE was 0.98, and r was 0.99, indicating a high goodness-of-fit. The probability of each monthly observation being included in the forecast range was about 64.4% on average, and by month, the predictability was relatively high in September, December, February, and January, and low in April, August, and March. The predicted range and median were in good agreement with the observations, except for some periods when temperature was dramatically lower or higher than in normal years. The quantitative temperature forecast information derived from this study will be useful not only for forecasting changes in temperature in the future period (1 to 12 months in advance), but also in predicting changes in the hydro-ecological environment, including evapotranspiration highly correlated with temperature.

• Economic and Environmental Geology
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• v.54 no.1
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• pp.105-115
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• 2021

The geological CO2 sequestration in underground geological formation such as deep saline aquifers and depleted hydrocarbon reservoirs is one of the most promising options for reducing the atmospheric CO2 emissions. The process in geological CO2 sequestration involves injection of supercritical CO2 (scCO2) into porous media saturated with pore water and initiates CO2 flooding with immiscible displacement. The CO2 migration and distribution, and, consequently, the displacement efficiency is governed by the interaction of fluids. Especially, the viscous force and capillary force are controlled by geological formation conditions and injection conditions. This study aimed to estimate the effects of surfactant on interfacial tension between the immiscible fluids, scCO2 and porewater, under high pressure and high temperature conditions by using a pair of proxy fluids under standard conditions through pendant drop method. It also aimed to observe migration and distribution patterns of the immiscible fluids and estimate the effects of surfactant concentrations on the displacement efficiency of scCO2. Micromodel experiments were conducted by applying n-hexane and deionized water as proxy fluids for scCO2 and porewater. In order to quantitatively analyze the immiscible displacement phenomena by n-hexane injection in pore network, the images of migration and distribution pattern of the two fluids are acquired through a imaging system. The experimental results revealed that the addition of surfactants sharply reduces the interfacial tension between hexane and deionized water at low concentrations and approaches a constant value as the concentration increases. Also it was found that, by directly affecting the flow path of the flooding fluid at the pore scale in the porous medium, the surfactant showed the identical effect on the displacement efficiency of n-hexane at equilibrium state. The experimental observation results could provide important fundamental information on immiscible displacement of fluids in porous media and suggest the potential to improve the displacement efficiency of scCO2 by using surfactants.

• Journal of the Korean Society of Marine Environment & Safety
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• v.28 no.6
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• pp.853-865
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• 2022

In this study, from August to October 2019, we conducted a survey of the spatial distribution and dominant species of macrobenthos on the rocky intertidal zones of 38 specified islands distributed along the southern coast of Korea. On the basis of observation made using 50 × 50 cm quadrats, we identified a total of 80 species, among which, Mollusca were the most abundant fauna, with 54 species that accounted for 67.4% of the total, followed by Crustacea with 15 species (18.7%). The recorded numbers of Cnidaria, Porifera, and Echinodermata species ranged from 1 to 6. In terms of the regional patterns of species richness, specified islands in Yeosu were found to be the most species rich, supporting 61 species, whereas islands in Hadong, Namhae, and Chujado were found to have a similar level of species richness, ranging from 42 to 46 species. Islands in Boseong and Goheung were home to the fewest species, with only 29 species being recorded. At the sampling station scale, we noted a considerable difference in faunal richness, ranging from 6 (St. 6) to 33 (St. 20) species. Among the recorded species, Echinolittorina radiata was identified as the dominant species on 15 specified islands, with the next most abundant species being Tetraclita japonica, considered an indicator species of climate change, which was recorded on 11 islands. In terms of frequency, E. radiata, found on 36 islands, was identified as the most frequently occurring species, followed by Reishia clavigera (30 islands), Mytilisepta virgata (29), Nerita japonica (28), Ligia. exotica (27), and Littorina brevicula (26). Of the 80 species identified, 9, 4, and 2 species of Mollusca, Crustacea, and Cnidaria, respectively, are classified as Marine fauna of accepted foreign export, whereas 50 are Red List species, 44 are species of Least Concern, 3 are Data Deficient species, and 1 species was not evaluated. However, during the survey, we found no Near Threatened or Not Applicable species. On the basis of the findings of this survey, it would appear that the abundance and richness of macrobenthic fauna inhabiting the rocky intertidal zones of specified islands along the southern coast of Korea differ according to different habitat conditions, particularly with respect to the duration of exposure and the extent and properties of the substrata. The findings of this study will provide baseline data for future monitoring and management of specified islands in Korea.

• Economic and Environmental Geology
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• v.56 no.3
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• pp.343-363
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• 2023

Sulawesi island, as a global producer of nickel resources, is leading the rapid growth of nickel industry of Indonesia. Nickel laterite deposits in Sulawesi was formed by lateritization of the world-scale East Sulawesi Ophiolite (ESO) under the active tectonic setting and tropical rainforest climate. In this paper, exploration cases for nickel laterite deposits in five regions of Sulawesi are reported. Regional characteristics on nickel laterite deposits in Sulawesi are understood based on various exploration activities such as outcrop, trench and pit survey, petrological observation, geochemical analysis, and interpretation of drilling data, etc.. In the northeastern part of 'Southeast-Arm', which is a strategic location for nickel industry of Indonesia, ESO is extensively exposed to the surface. In the Morombo and Morowali regions, typical high-grade saprolite-type orebodies with a thickness of 10 to 20 m occur. The cases showed that topographic relief tends to regulate Ni-grade distribution and orebody thickness, and that high grade intervals tend to occur in places where joints and garnierite veins are dense. In the Tinanggea and South Palangga regions in the southern part of the Southeast-Arm, overburden composed of Neogene to Quaternary deposits is a major factor affecting the preservation and profitability of nickel laterite deposits. Despite the overburden, high-grade saprolite-type orebodies composed of Ni-bearing serpentine with garnierite veins occur in a thickness of around 10 m to secure economic feasibility. In contrast, in the Ampana region in the northern part of 'East-Arm', low-grade nickel laterite deposits with immature laterite profile was identified, which is thought to be the result of active denudation due to tectonic uplift. Exploration cases in this paper will help to understand characteristics and controlling factors on nickel laterite deposits in Sulawesi, Indonesia.

• The Journal of the Society of Stroke on Korean Medicine
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• v.12 no.1
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• pp.16-23
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• 2011

Object : The purpose of this study is to observe the changes of symptoms and signs diagnosised by differentiation of the pattern identification in stroke patients. Methods : Seventy subjects were recruited from patients with stroke within ten days of onset. We chose twenty-nine subjects diagnosised as same differentiation of the pattern identification, and who had at least on follow up session. We had investigated change of symptoms and signs diagnosised by differentiation of the pattern identification. Results : There were five symptoms and signs (thick fur, dry fur, difficult defecation, heat vexation and aversion to heat, normal pulse) and ten (heavy-headedness, frequency of defecation, hard defecation, feel heavy, slippery pulsem, dry mouth, bitter taste in the mouth, feel lazy, look lazy) symptoms and signs that were statistically significant improved in fire-heat patterns and dampness-phlegm pattern, respectively. Conclusions : This study provides evidence that collaborative treatment is effective in improving some symptoms and signs in acute ischemic stroke patients diagnosised by fire-heat pattern and dampness-phlegm pattern. Further studies with larger scale, longer observation period would be required.

• Journal of the Korean Institute of Landscape Architecture
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• v.51 no.3
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• pp.83-94
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• 2023

This study analyzed the satisfaction of green infrastructure around 39 dams, including multi-purpose dams, water dams, and flood control reservoir dams, to induce space improvement in terms of sustainability, and the results of the study are as follows. First, the satisfaction level based on the Likert scale of 5 points for the currently created dam green infrastructure was 3.76, and there were differences depending on the respondents' gender, age, residence, number of dam visits, and the need to pursue sustainability, and it was analyzed to be statistically significant. In the case of gender, p<.05, age, residence, number of dam visits, and the need to pursue sustainability were found to be p<.01. Regression analysis was conducted to confirm the effect of these respondents' characteristics on satisfaction, and it was analyzed that only the number of dam visits and the need to pursue sustainability had a statistically significant effect, and other characteristic variables had no significant effect. Second, in terms of satisfaction with the conceptual image of public bridge, view place and play space, which are the main spaces of dam green infrastructure considering sustainability, view place was the highest at 4.43, the play space was 4.35 and public bridge was analyzed as 4.21. The t-test result for the satisfaction of each space was found to be p<.01, and the difference in values was analyzed to be significant. The difference from the current satisfaction with green infrastructure was also analyzed as p<.00, showing a statistically significant difference. Third, as a way to revitalize green infrastructure around the dam through the results of satisfaction analysis, it is necessary to identify needs for major visitors in their 40s and 50s and create a space considering them. It was proposed to derive facilities and programs that can be introduced to other regions through the analysis of green infrastructure status around dams in Chungbuk, Jeonju, and Ulsan, where there are relatively many dams. Furthermore, satisfaction analysis by space showed that green infrastructure around the dam could be activated in terms of sustainability when selecting packaging materials considering the structure and shape of the dam, arranging observation facilities considering lake prospects, and introducing amusement facilities using local environmental resources. This study differs from previous studies in that it presented space improvement measures in consideration of sustainability for green infrastructure around dams for non-urban areas, and space improvement can contribute to improving it connectivity in urban and non-urban areas, which can also contribute to improving the sustainability of green infrastructure in Korea.

• Asia-Pacific Journal of Business Venturing and Entrepreneurship
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• v.18 no.3
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• pp.61-79
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• 2023

This study is a case study of overseas banana farms as a global agricultural startup that has hardly been attempted so far in terms of paradigm shift in the industry, beyond regional limitations. It was researched for the purpose of revealing the success factors of 'global agricultural startup' in terms of business process, entrepreneurship, and management dimensions learned through direct participation and observation at the local level. In order to study global agricultural startups, this study also conducted a comparative analysis of global startups (global startups) and global agricultural startups(global agricultural startups). In fact, the analysis consists of 'definition', 'components', and 'success factors', and we want to confirm the difference between the two concepts that can be distinguished. The case analysis tried to maximize the advantages of 'participatory action research' by directly observing and experiencing banana farms. In the case of banana farm cases, by dividing them into preparation process for farm development and farm development and management process, various variables considered in farm management were explained through the whole process of farm management. Through the process of overcoming and responding to specific failure cases, we tried to secure the reliability and validity of the research, and the case studies related to entrepreneurship, management, and organization analyzed by applying them by subdividing them into theoretical areas belonging to components and management that were theorized in existing preceding studies. This study is almost the first study on the process of creating a local entry business by directly moving the head office overseas rather than entering overseas agriculture as a subsidiary, joint venture or overseas corporation. In particular, it is a unique case that corresponds to agriculture in terms of region(Africa), scale(startup), and industry that have not been introduced so far as a global agricultural startup. In terms of entrepreneurship, it also concretely exemplified how entrepreneurship components such as innovativeness, risk-taking propensity, proactiveness, vision sharing, social contribution, leadership, etc., which have not been attempted so far in agricultural cases, are manifested and effective. The management and cultural aspects also went beyond the argument that only cultural aspects are important in overseas business, and also confirmed individual failure cases and their responses in recruitment, job, wage, retirement, development, organizational structure management, etc. As a result, there is significance and implications of this study in that it provides theoretical confirmation as well as practical and responsive basis for 'entrepreneurship', 'farming management', and 'management' aspects in overseas agricultural startup business operation.