• The Journal of the Korea Contents Association
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• v.21 no.12
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• pp.375-383
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• 2021

Due to COVID-19, people are building new lifestyles such as online shopping, online travel, and video conferencing by limiting going out and gatherings. Such rapid social change is causing new problems and deepening existing problems at the same time. In particular, as online consumption increases significantly, traffic congestion, air pollution, and the heavy workload of delivery drivers are deepening in the daily logistics industry, and face-to-face delivery is emerging as a new problem. With the advent of the 4th industrial revolution, unmanned delivery using drones, artificial intelligence, and autonomous driving is emerging as an alternative to the existing logistics industry. However, space for logistics facilities and securing additional logistics sites due to drone flight are emerging as new problems to be solved. Therefore, it is intended to link additional services such as logistics movement, storage, and delivery by utilizing the existing transportation business, the subway, as a space for a logistics facility for drones that can solve existing problems and new problems.

• Journal of Korean Tunnelling and Underground Space Association
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• v.24 no.3
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• pp.293-304
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• 2022

Recently, the frequency of installation of ventilation towers is increasing due to the planning and construction of underground roads and long tunnel. In this study, implications and points for improvement were considered through investigation and analysis of the installation standards related to ventilation towers in tunnels and analysis of ventilation tower installation cases in domestic and overseas tunnel case study. As a result of this study, when selecting the location and height of the ventilation tower, it is recommended to determine the final ventilation tower type through a consultation process with residents, considering the environmental impact caused by the emission of pollutants, the harmonious arrangement with the surrounding landscape, and the efficient use of the above-ground site nearby ventilation tower. In addition, from the design stage, it is judged that a detailed review of reducing the height of the ventilation tower through air quality simulation is necessary for natural harmony with the surrounding topography and to prevent civil complaints.

• Journal of Korean Society of Environmental Engineers
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• v.27 no.10
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• pp.1072-1080
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• 2005

The extraction characteristics of heavy metals(HM) from a contaminated soil at existing lead smelters were investigated with ethylene diamine tetraacetic acid(EDTA), citrate and HCl as washing solutions. EDTA was more effective for Pb than for other heavy metals. As the mol ratio of EDTA/HM increased, the removal efficiency of heavy metals became higher. When the mol ratio of EDTA/HM approached to 6.5, it removed Pb most effectively. Citrate was effective especially in extracting Zn. The removal efficiency of HCl was comparatively high in almost all heavy metals, and at 0.3N concentration it was the highest. After soil washing process by the use of EDTA, the great part of exchangeable fractions and most of heavy metals of weakly adsorbed like carbonate fraction were extracted. For washing with citrate and HCl, four heavy metals showed the similar exchange of chemical partitioning and the exchangeable fractions of Pb which has weakly adsorbed to soil were more increased than before the process. As removal efficiency of citrate washing process depends upon the distribution of non-detrital fractions, so it can be contended that only the amount of non-detrital fractions could be removed from all the heavy metal content. EDTA and HCl could remove most of non-residual fractions in all heavy metals except Zn. As a result of EDTA washing, toxicity characteristic leaching procedure(TCLP) concentration of the processed soil met the USEPA Pb limit of 5.0 mg/L.

• Journal of Soil and Groundwater Environment
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• v.12 no.1
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• pp.53-63
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• 2007

Soil risk assessment models were used to determine the goals of soil remediation and to establish the soil quality standards in developed countries. Recently, Korean Ministry of Environment prepared the guideline for soil risk assessment. Soil risk assessment model applicable to Korean situation will be needed in the near future. In this study, three models for soil risk assessment were extensively compared to suggest the fundamental components that required for the soil risk assessment in Korea. The models considered in this study were CalTOX in the United States, CLEA (Contaminated Land Exposure Assessment) in the United Kingdom, and CSOIL in the Netherlands. The major exposure routes and the intake estimation equations suitable for Korean situation were suggested. The exposure routes suggested were intake of the crops, underground water, indoor outdoor soil ingestion, dust inhalation and a volatile matter inhalation. The equations for intake estimation used in CalTOX and CSOIL seem to be applicable for the calculation of the human intake in Korea.

• Journal of the Korean Institute of Landscape Architecture
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• v.43 no.1
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• pp.96-107
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• 2015

Brownfield sites are beginning to be considered as potentially useful areas for landscape design and planning, with post-industrial areas such as water treatment facilities and military training bases being converted into useful landscapes such as parks and recreation areas. These redevelopments bring broad benefits through revitalizing communities and increasing property values, thus, increasing the demand for comprehensive management and planning policies. This study examines changes in U.S. brownfield policies and programs and, identifies their periodic characteristics over the thirty years since the Superfund program was introduced in 1980. A descriptive and interpretive approach was utilized, focusing specifically on a time sequential analysis of the data gathered from the overview of the Environmental Protection Agency's web-based documents and related literature. The primary changes in and characteristics of programs and policies were analyzed and divided into three periods : environmental protection, remediation and reuse, and comprehensive planning. Four major features were identified: relaxation and readjustment of regulation, diversification of support programs, a mix of top-down and bottom-up approaches, and database system building. The study examines how common brownfield problems such as site identification difficulties and assessment and remediation cost have been dealt with in the regulatory context and has implications for future policies and programs for effective brownfield planning and management in Korea.

• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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• v.14 no.3
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• pp.201-209
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• 2016

The object of this study was to evaluate the separation distance from a temporary storage facility satisfying the dose criteria. The calculation of ambient dose rates took into account cover soil thickness, facility size, and facility type by using MCNPX code. Shielding effects of cover soil were 68.9%, 96.9% and 99.7% at 10 cm, 30 cm and 50 cm respectively. The on-ground type of storage facility had the highest ambient dose rate, followed by the semi-ground type and the underground type. The ambient dose rate did not vary with facility size (except $5{\times}5{\times}2m\;size$) due to the self-shielding of decontamination waste in temporary storage. The separation distances without cover soil for a $50{\times}50{\times}2m\;size$ facility were evaluated as 14 m (minimum radioactivity concentration), 33 m (most probably radioactivity concentration), and 57 m (maximum radioactivity concentration) for on-ground storage type, 9 m, 24 m, and 45 m for semi-underground storage type, and 6 m, 16 m, and 31 m for underground storage type.

• Journal of Radiation Industry
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• v.9 no.4
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• pp.209-216
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• 2015

It has been about 5 years since the Fukushima nuclear power plant accident, which contaminated large area with radioactive materials. It is necessary to assess radiation dose to establish evacuation areas and to set decontamination goal for the large contaminated area. In this study, we assessed temporal trend of radiation dose to the public living in the large area contaminated with radioactive materials after the Fukushima nuclear power plant accident. The dose assessment was performed based on Chernobyl model and RESRAD model for two evacuation lift areas, Kawauchi and Naraha. It was reported that deposition densities in the areas were $4.3{\sim}96kBq\;m^{-2}$ for $^{134}Cs$, $1.4{\sim}300kBq\;m^{-2}$ for $^{137}Cs$, respectively. Radiation dose to the residents depended on radioactive cesium concentrations in the soil, ranging $0.11{\sim}2.4mSv\;y^{-1}$ at Kawauchi area and $0.69{\sim}1.1mSv\;y^{-1}$ at Naraha area in July 2014. The difference was less than 5% in radiation doses estimated by two different models. Radiation dose decreased with calendar time and the decreasing slope varied depending on dose assessment models. Based on the Chernobyl dosimetry model, radiation doses decreased with calendar time to about 65% level of the radiation dose in 2014 after 1 year, 11% level after 10 years, and 5.6% level after 30 years. RESRAD dosimetry model more slowly decreased radiation dose with time to about 85% level after 1 year, 40% level after 10 years, and 15% level after 30 years. The decrease of radiation dose can be mainly attributed into radioactive decays and environmental transport of the radioactive cesium. Only environmental transports of radioactive cesium without consideration of radioactive decays decreased radiation dose additionally 43% after 1 year, 72% after 3 years, 80% after 10 years, and 83% after 30 years. Radiation doses estimated with cesium concentration in the soil based on Chernobyl dosimetry model were compared with directly measured radiation doses. The estimated doses well agreed with the measurement data. This study results can be applied to radiation dose assessments at the contaminated area for radiation safety assurance or emergency preparedness.

• Economic and Environmental Geology
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• v.55 no.4
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• pp.353-366
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• 2022

Spatial estimation of geoscience data (geo-data) is challenging due to spatial heterogeneity, data scarcity, and high dimensionality. A novel spatial estimation method is needed to consider the characteristics of geo-data. In this study, we proposed the application of Gaussian Mixture Model (GMM) among machine learning algorithms with multivariate data for robust spatial predictions. The performance of the proposed approach was tested through soil chemical concentration data from a former smelting area. The concentrations of As and Pb determined by ex-situ ICP-AES were the primary variables to be interpolated, while the other metal concentrations by ICP-AES and all data determined by in-situ portable X-ray fluorescence (PXRF) were used as auxiliary variables in GMM and ordinary cokriging (OCK). Among the multidimensional auxiliary variables, important variables were selected using a variable selection method based on the random forest. The results of GMM with important multivariate auxiliary data decreased the root mean-squared error (RMSE) down to 0.11 for As and 0.33 for Pb and increased the correlations (r) up to 0.31 for As and 0.46 for Pb compared to those from ordinary kriging and OCK using univariate or bivariate data. The use of GMM improved the performance of spatial interpretation of anthropogenic metals in soil. The multivariate spatial approach can be applied to understand complex and heterogeneous geological and geochemical features.

• The Journal of Engineering Geology
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• v.33 no.1
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• pp.85-103
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• 2023

The in-situ remediation of a solidified stratum containing a large amount of fine-texture material like clay or organic matter in contaminated soil faces limitations such as increased remediation cost resulting from decreased purification efficiency. Even if the soil conditions are good, remediation generally requires a long time to complete because of non-uniform soil properties and low permeability. This study assessed the remediation effect and evaluated the field applicability of a methodology that combines pneumatic fracturing, vacuum extraction, and plasma blasting (the PPV method) to improve the limitations facing existing underground remediation methods. For comparison, underground remediation was performed over 80 days using the experimental PPV method and chemical oxidation (the control method). The control group showed no decrease in the degree of contamination due to the poor delivery of the soil remediation agent, whereas the PPV method clearly reduced the degree of contamination during the remediation period. Remediation effect, as assessed by the reduction of the highest TPH (Total Petroleum Hydrocarbons) concentration by distance from the injection well, was uncleared in the control group, whereas the PPV method showed a remediation effect of 62.6% within a 1 m radius of the injection well radius, 90.1% within 1.1~2.0 m, and 92.1% within 2.1~3.0 m. When evaluating the remediation efficiency by considering the average rate of TPH concentration reduction by distance from the injection well, the control group was not clear; in contrast, the PPV method showed 53.6% remediation effect within 1 m of the injection well, 82.4% within 1.1~2.0 m, and 68.7% within 2.1~3.0 m. Both ways of considering purification efficiency (based on changes in TPH maximum and average contamination concentration) found the PPV method to increase the remediation effect by 149.0~184.8% compared with the control group; its average increase in remediation effect was ~167%. The time taken to reduce contamination by 80% of the initial concentration was evaluated by deriving a correlation equation through analysis of the TPH concentration: the PPV method could reduce the purification time by 184.4% compared with chemical oxidation. However, the present evaluation of a single site cannot be equally applied to all strata, so additional research is necessary to explore more clearly the proposed method's effect.

• Proceedings of the Korean Vacuum Society Conference
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• 2015.08a
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• pp.83-83
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• 2015

현재 인류가 직면한 에너지 부문의 큰 난제는 화석연료의 한정된 매장이기도 하지만 그 사용에 따른 환경오염으로 인한 피해들이 더 큰 문제로 대두되고 있다. 그중 지구 온난화의 영향으로 최근 세계에 국지적인 홍수, 가뭄, 태풍등의 기후 불안정으로 피해보는 상황이 가속화 되고 있다. 또한, 북극지방의 해빙으로 해수면 상승이 예상되며 머지않은 시간에 해수면 상승의 직접적인 피해가 인류에게 오리라는 보고가 많이 발표되고 있다. 그런데 우리가 더욱 중요한 것은 지구촌83의 관성이 크기 때문에 지구 온난화 와 해수면 상승이 인류에 큰 피해를 미치기 시작할 때는 이미 돌이킬 수 없는 상황에 진입해버린다는 사실을 간과하고 있는다는 것이다. 그러므로 과학적 분석에 근거하여 피해를 축소하기위한 활동을 실천해야할 시기이다. 특히, 우리나라의 경우 에너지의 97% 이상을 해외에서 수입하고 있으며, 세계에너지 소비 10위, 석유 소비 7위의 열악한 에너지 자원 빈국인 만큼, 중장기적인 관점에서 석유의존도를 개선하고 신재생에너지원을 확보하는 등 대책마련이 시급한 실정이다. 신재생에너지원으로 현재까지 가장 큰 역할을 해왔던 것 중의 하나가 풍력발전기인데, 오늘날 세계 풍력에 의한 발전량은 세계 총 발전량의 2% 미만에 불과하이다. 이러한 풍력 시장에 발맞춰 국내에서도 풍력발전기 개발에 많은 힘을 쏟고 있는데, 2002년부터 750 kW급 풍력발전기가 처음 개발되기 시작하였고, 이후 2 MW급 풍력발전기와 3 MW급 풍력발전기가 개발되었으며, 최근에는 5 MW와 7.5 MW급등 초대형 풍력발전기가 대기업 중심으로 개발 진행되고 있었으나, 2008년 세계 금융위기 이후 세계 경기침체의 영향으로 국내 풍력산업도 적지않은 영향으로 구조조정되어 기존 7~8개 풍력발전기 제조사들이 3개사 이하로 축소되고 있다. 이에 정부 및 전라남도는 해상풍력산업을 침체기를 겪는 조선산업의 대체산업으로 육성하기위해, 정부 주도로 부안 앞바다에 2.5 GW 해상풍력발전단지개발을 준비 중에 있으며, 전라남도는 전남 서해안에 4 GW 해상풍력발전단지 개발을 서두드고 있다. 특히, 전라남도는 국내에서 가장 많은 풍력에너지 포텐셜을 가지고 있으며, 바람의 질 또한 우수하여 이를 지역산업 활성화의 모멘텀으로 가져가기위해 많은 노력을 기울이고 있다. 그 일례로 영광군 백수읍 하사리 바닷가 $4,342m^2$ 부지에 "풍력테스트베드"를 개발하여 국내 풍력발전기 제조사들이 활용하도록 도움을 주고 있다. 종래의 테스트베드는 해외지역을 이용하였는데, 이는 국내에서 개발된 풍력발전기들이 국제인증을 받기위해 바람의 질이 좋은 해외 테스트베드에 설치되어 평가받았으며 고가의 비용이 소모되었다. 제주도에 테스트베드 장소가 있긴 하지만 수용 규모가 작아 풍력발전기 제조사들이 대기할 수 없어 해외로 나가는 실정에 전라남도의 내륙 테스트베드를 개발함으로서 풍력발전기 제조사들에게 큰 도움을 주고 있다. 본 보고에서는 국가 해상풍력 산업발전의 단계별 전략과 전라남도의 해상풍력산업의 방향 그리고 풍력테스트베드의 현황을 소개하고자 한다.