• Journal of Soil and Groundwater Environment
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• v.24 no.2
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• pp.23-37
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• 2019

To evaluate the available groundwater supply to the agricultural water demand in the future with the climate change scenarios for 40 sub-regions in Jeju Island, groundwater recharge and the available groundwater supply were estimated using water balance analysis method. Groundwater recharge was calculated by subtracting the actual evapotranspiration and direct runoff from the total amount of water resources and available groundwater supply was set at 43.6% from the ratio of the sustainable groundwater capacity to the groundwater recharge. According to the RCP 4.5 scenario, the available groundwater supply to the agricultural water demand is estimated to be insufficient in 2020 and 2025, especially in the western and eastern regions of the island. However, such a water shortage problem is alleviated in 2030. When applying the RCP 8.5 scenario, available groundwater supply can't meet the water demand over the entire decade.

• Journal of Korea Water Resources Association
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• v.54 no.7
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• pp.485-493
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• 2021

Groundwater is an important water resource that can be used along with surface water. In particular, in the case of island regions, research on groundwater level variability is essential for stable groundwater use because the ratio of groundwater use is relatively high. Researches using artificial intelligence models (AIs) for the prediction and analysis of groundwater level variability are continuously increasing. However, there are insufficient studies presenting evaluation criteria to judge the appropriateness of groundwater level prediction. This study comprehensively analyzed the research results that predicted the groundwater level using AIs for various regions around the world over the past 20 years to present the range of allowable groundwater level prediction errors. As a result, the groundwater level prediction error increased as the observed groundwater level variability increased. Therefore, the criteria for evaluating the adequacy of the groundwater level prediction by an AI is presented as follows: less than or equal to the root mean square error or maximum error calculated using the linear regression equations presented in this study, or NSE ≥ 0.849 or R² ≥ 0.880. This allowable prediction error range can be used as a reference for determining the appropriateness of the groundwater level prediction using an AI.

• Korean Journal of Soil Science and Fertilizer
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• v.44 no.6
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• pp.1010-1015
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• 2011

The objectives of this study were to investigate soil chemical characteristics for forest rehabilitation and suggest management in abandoned coal mine areas in Hwasun-gun, South Jeolla Province. Total study sites were 8 sites, and soil analysis particular were soil pH, TOC, total-N, C/N ratio, Avail. $P_2O_5$, and CEC. Average soil pH was 5.8 (4.7~6.4). Average contents of TOC, total-N and C/N ratio were 1.1% (0.2~2.0%), 0.08% (0.02~0.13%) and 15.0 (7.9~31.4), respectively. Average Avail. $P_2O_5$ was $8.3mg\;kg^{-1}$ (2.7~15.0) and Average CEC was $13.7cmol_c\;kg^{-1}$ ($9.9{\sim}18.5cmol_c\;kg^{-1}$). Soil pH was decreased according to elapsed time from forest rehabilitation, while TOC, total N and CEC were increased. Av. $P_2O_5$ did not show any relationship with elapsed time. Soil pH was stable comparing with general forest soil in South Jeolla Province (5.1), while contents of TOC and total N were lower than general forest soil in South Jeolla Province (4.9% and 0.18%, respectively). Therefore, sustainable managements such as fertilization for TOC and total N are necessary for good rooting and growth of vegetation.

• Journal of The Korean Society of Agricultural Engineers
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• v.65 no.6
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• pp.79-91
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• 2023

This study surveyed the actual status of reclamation areas in South Pyongan Province, North Korea, using satellite images and literature to survey the creation date, area, and length of the embankment of the reclamation areas. The reclamation areas in South Pyongan Province were created in three stages, with the first stage completed in the late 1970s or early 1980s, the second stage in the late 1980s or early 1990s, and the third stage in the 2000s. The total area of the reclamation areas is 105,570 hectares. The land cover of the reclamation areas is as follows: agriculture (50.5%), saltern (29.5%), water bodies (13.6%), foreshore (12.4%), grasslands (3.0%), bare land (0.4%), facility (0.1%), and forests (0.1%). The study also found that the NDVI values of the reclamation areas vary depending on the location. The NDVI values of the Gwiseong and Namyang reclamation areas are low, while the NDVI values of the Samcheonpo and Jigdongbaedali reclamation areas are high. The study found that the NDVI values of the reclamation areas are correlated with the land cover of the reclamation areas. The study's findings can be used to understand the development direction and regional characteristics of the reclamation areas in South Pyongan Province. The study's findings can also be used to develop policies and plans for the sustainable development and utilization of the reclamation areas in South Pyongan Province.

• Journal of Soil and Groundwater Environment
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• v.23 no.1
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• pp.92-105
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• 2018

In this study, the projected land use area in 2030 for major crop production was estimated in Jeju Island using land cover map, and corresponding agricultural water demand for 40 sub-regions was quantitatively assessed using the future climate change scenario (RCP 4.5). Estimated basic unit of water demand in 2030 was the highest in the western region, and the lowest in the eastern region. Monthly maximum agricultural water demand analysis revealed that water demand in August of 2030 substantially increased, suggesting the climate of Jeju Island is changing to a subtropical climate in 2030. Agricultural water demand for sub-region in 2030 was calculated by multiplying the target area of the water supply excluding the area not in use in winter season by the basic unit of water demand, and the maximum and minimum values were estimated to be $306,626m^3/day$ at Seogwipo downtown region and $77,967m^3/day$ at Hallim region, respectively. Consequently, total agricultural water demand in Jeju Island in 2030 was estimated to be $1,848,010m^3/day$.

• Journal of Environmental Health Sciences
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• v.41 no.2
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• pp.61-70
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• 2015

Objectives: The purpose of this research was to examine radon exposure in terms of the relationship between the living environment and indoor radon concentrations among vulnerable households. Methods: Nationwide, 1,129 subjects were selected using personal questionnaires for adequately understanding the living environment, installation of E-PERM radon gas detectors, and investigation of the structure of the housing. Results: The mean concentration of indoor radon for all subjects was $130.2Bq/m^3$ (GM=101.7), and a total of 438 subjects (38.8%) exceeded the recommended standards ($148Bq/m^3$) for public facilities by the Ministry of the Environment. By location, the highest concentrations ($164.3Bq/m^3$, GM=124.1) were seen in North Chungcheong Province. In the case of the Seoul/Gyeonggi Province metropolitan area, they showed $125.6Bq/m^3$ (GM=105.1) and $118.9Bq/m^3$ (GM=96.5), respectively. By type of housing, indoor radon concentrations in single-family housing were higher than in row/multi-family housing (p<0.01). Although indoor radon concentrations raised in accordance with year of construction (p<0.05), the difference between indoor radon concentrations in underground residences was not observed to be statistically significant (p=0.633). Conclusion: More studies are necessary in the future regarding the difference in indoor radon concentrations that may occur due to different of types of indoor construction, building materials, and the amount of building materials.

• International Journal of Contents
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• v.7 no.2
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• pp.32-35
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• 2011

This research would be the first step toward in the long processes of proton technology industrial cluster development by focusing on the region's readiness and acceptability of the proton technology project. As is shown in our questionnaire survey, the top priorities needed to consider for the Proton Technology project are found to be job creation (mean 3.74), regional economic development (mean 3.72), industry infrastructure(3.54), institution for science and education(3.53), economic inequalities(3.33), tourism industry revitalization(3.20). For public servants top priorities in order found to be regional economic development, job creation, industry infrastructure, institution for science and education, economic inequalities, tourism industry revitalization. Universities' priorities in order found to be job creation, regional economic development, institution for science and education, industry infrastructure, economic inequalities, tourism industry revitalization. The mean reliability score for the each party was found to be mayor((3.04), citizens(2.99), province(2.97), private corporation(2.96), and universities((2.93). Of particular note, the mean score except the mayor were all below median (3.00). province(3.24), city council member(3.20), public employees (3.09), private corporation(3.03), nonprofit organization (2.97), mass media (2.96), citizens(2.96), and universities(2.89). The universities and colleges also should revise their strategic plans and thus restructure their internal academic programs, and must develop their own collaborative programs with Proton Engineering Frontier Project, related industries, city, and other government units. Not only educating, training, and providing top-notched man powers to the proton technology industries will be one of their primary missions.

• Proceedings of the KIEE Conference
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• 2008.09a
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• pp.269-270
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• 2008

본 논문에서는 캐나다 중서부에 위치한 BC(British Columbia)주 및 AB(Alberta)주의 수용가 전력설비에 대한 전기안전 시스템에 대해 고찰하였다. 캐나다의 전기안전은 주정부 권한을 위임받은 안전청에서 담당하며, 세부적인 안전관리는 각 주마다 절차 상 약간의 차이는 있었지만, 전체적으로 전기안전이라는 큰 틀 안에서 동일한 맥락으로 통제되고 있었다. 또한, 국내에 비해 전기안전 교육 프로그램 및 홍보가 상당히 강화되어 있음을 알 수 있었다.

• Proceedings of the KSEEG Conference
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• 2005.04a
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• pp.78-81
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• 2005

• Proceedings of the KIEE Conference
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• 2005.07a
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• pp.545-547
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• 2005

345kV youngheung tansmission line which has been constructed in the western sea is the first and the largest marine project in the world crossing the youngheung island and the sihwa bay. It helps the stabilization of power supply greatly to cope with the rapid growth of the electric power consumption in the metropolitan areas and Gyeonggi province. Haying constructed the project successfully with the purely domestic-developed technologies, KEPCO is able to not only accumulate more advanced technologies of the marine project but also establish a bridgehead toward overseas market. It is very meaningful that we completed project successfully in spite of many difficulties including the uncertainty of the first project in the sea and strong objections from the environment groups and local residents. In this paper I will briefly introduce the project, newly developed technologies and materials.