• Proceedings of the Korea Water Resources Association Conference
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• 2022.05a
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• pp.510-511
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• 2022

물관리기본법의 시행 및 제1차 국가물관리기본계획의 이행에 따라 물관리 자료의 정보화 요구가 증가하고 있다. 과거 농업용수관리는 기초자료의 오류, 계측데이터의 부족 등이 한계점으로 지적되었으며, 과학화·표준화된 농업용수 물수급 분석 체계 구축 및 물정보의 정확성이 요구된다. 최근 통합물관리 국가정책 대응을 위한 물수급 분석 기반 마련을 목적으로 한국농어촌공사에서는 농업용수 용 배수 계통 정밀조사, 공간자료 재구축 등을 통한 농업용수 디지털 정보체계 구축 사업이 진행되고 있다. 연속수치지형도 및 토지피복, 스마트팜맵 등의 디지털 공간자료를 수집하고 현장조사와 영농조사를 바탕으로 최신화된 용배수계통도, 수혜면적 자료를 구축하였다. 본 연구에서는 디지털화한 용배수계통도를 이용하여 수리해석 모델 기초자료를 구축하고, 들녘단위 (주·보조수원, 저수지 및 양수장 등) 용수계통도 구현함으로써 수원공별 용수공급 네트워크를 분석하고자 한다. 농업용수 공급체계 반영이 가능한 EPA-SWMM (United States Environmental Protection Agency Storm Water Management Model)을 활용하여 다양한 물공급 시나리오를 적용하여 최적의 물관리 방안을 제시하고자 한다. 본 연구에서는 경기도 안성시 고삼저수지를 대상으로 연속수치지형도, 농경지전자지도, 고해상도 DEM 등을 활용한 디지털 조사와 수로 표고, 길이 및 너비 등 현장조사를 수행하였으며, 현장 물관리 방안을 적용하여 물분배 모의가 가능한 EPA-SWMM 기반 수원공-용수로-수혜구역을 연결하는 용수공급 네트워크를 구축하였다. 농촌용수종합정보시스템 (Rural Agricultural Water Resource Information System, RAWRIS)에서 제공하는 계측 자료를 활용하여 관개기간의 강수량, 소비수량, 증발산량, 공급량 등을 적용하여 농업용수 공급량, 배분량을 추정하였다. 본 연구의 결과는 물관리 담당자에게 상세한 현행 용수공급량 및 용수공급체계 정보 제공과 향후 국가물관리기본계획, 농어촌용수이용합리화계획의 물수급 분석 기초자료로 활용 가능할 것으로 사료된다.

• Economic and Environmental Geology
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• v.52 no.5
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• pp.357-366
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• 2019

Deposition of the Daedong Supergroup has been considered to be related with the Triassic Songrim and Jurassic Daebo orogenies. The Chungnam Basin fills is an important sedimentary succession to understand the geological evolution of the Early to Middle Mesozoic Korean Peninsula. Previous paleontological and paleomagnetic studies have suggested the Late Triassic to Early Jurassic sedimentation of the Chungnam Basin fills. However, the orogenic model of the basin development has remained controversial because recently reported zircon U-Pb isotopic ages are not harmonious with the previous studies. This paper aims to review the stratigraphy, depositional age, and composition of the Chungnam Basin fills, together with test of the basin development models.

• Journal of Korean Society of Environmental Engineers
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• v.33 no.4
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• pp.281-288
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• 2011

Recently, researches that a variety of contaminants in water are removed by sonolysis technology with oxidation and pyrolysis process from cavitation were conducted. However, there are few studies for sonochemical treatment by a pilot-scale ultrasound system. This research focused on developing pilot-scale ultrasound systems, which could be an continuously effective treatment for a large volumes of contaminants, and demonstrating the feasibility of utilizing these systems to remove naphthalene from groundwater. V-120 type reactor was found to be 1.4~2.2 times higher effective than the normal type. A total of three different pilot scale's systems consisted of installing effluent and irrigation water in order to be a continuos system, including supplemental additives, and applying a V-120 type reactor and a external cooling cycle system. Naphthalene levels treated by three systems were lower than a recommended guideline of naphthalene for drinking water in EPA. Especially, the naphthalene removal efficiencies of PS1 and PS2 systems were over 97%. The pilot-scale continuous ultrasound clean-up system delivered over 84~95% naphthalene removal efficiency for treatment of 10~20 liter of groundwater. In addition, the ultrasound system could be successfully applied to the conditions of artificial and genuine groundwater contaminated with naphthalene.

• Journal of the Korean Society of Marine Environment & Safety
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• v.28 no.4
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• pp.648-656
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• 2022

As environmental regulations such as the International Maritime Organization (IMO)'s strategy to reduce greenhouse gases(GHG) are strengthened, technology development such as eco-friendly ships and alternative fuels is expanding. As part of this, ship propulsion technology using energy reduction and wind propulsion technology is emerging, especially in shipping companies and shipbuilders. By securing wind propulsion technology and introducing empirical research into shipbuilding and shipping, a high value-added market using eco-friendly technology can be created. Moreover, by reducing the fuel consumption rate of operating ships, GHG can be reduced by 6-8%. Rotor Sail (RS) technology is to generate a hydrodynamic lift in the vertical direction of the cylinder when the circular cylinder rotates at a constant speed and passes through the fluid. This is called the Magnus effect, and this study attempted to propose a plan to increase propulsion efficiency through a numerical analysis study on turbulence flow characteristics around RS, a wind power assistance propulsion system installed on a ship. Therefore, C_L and C_D values according to SR and AR changes were derived as parameters that affect the aerodynamic force of the RS, and the flow characteristics around the rotor sail were compared according to EP application.

• Journal of the Korean Society of Marine Environment & Safety
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• v.29 no.2
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• pp.197-206
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• 2023

Recently, the international community, including the International Maritime Organization (IMO), has strengthened regulations on air pollution emissions of ships, and eco-friendly ships are actively being developed to reduce exhaust gas emissions. Among them, rotor sail (RS), a wind-assisted ship propulsion system, is attracting attention again. RS is a cylindrical device installed on the ship deck, that generates hydrodynamic lift using a magnus effect. This is a next generation eco-friendly auxiliary propulsion technology, and Enercon company, which developed RS-applied ships, announced that fuel savings of more than 30% are possible. In this study, optimal installation conditions such as RS spacing and arrangement type were selected when multiple RSs were installed on ships. AR=5.1, SR=1.0, and D_e/D was fixed at 2.0 according to the RS arrangement, and the wind direction was considered only for the unidirectional +y-axis. Regarding arrangement conditions, five conditions were set at 3D intervals in the +x-axis direction from 3D to 15D and five conditions in the +y-axis direction from 5D to 25D. C_L, C_D and aerodynamic efficiency (C_L/C_D) were compared according to the square(□) and diamond(◇) shape arrangements. Consequently, the effect of RS on the longitudinal distance was not significantly different. However, in the case of RS flow characteristics according to the transverse distance, the interaction effect of RS was the greatest when the two RSs almost matched the wind direction. In the case of the RS flow characteristics according to the arrangement, notably, when the wind blew in the forward (0°) direction, the diamond (◇) arrangement was least affected by the backward flow between RSs.

• Microbiology and Biotechnology Letters
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• v.3 no.3
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• pp.123-134
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• 1975

Out of 96 yeast strains isolated from various natural habitats, five strains were screened based on their ability to ferment agricultural biproducts such as rice-, barley-and wheat-bran, and sawdust. These were identified as Hansenula anomala var anomala, Candide utilis, C. pelliculosa, Debaryomyces hansenii, and Irpex lacteus. Using these yeasts the above mentioned agricultural biproducts were fermented in various combinations. The fermented product was fed to 180 male Starcroses for eight weeks and obtained a body weight increase of 15.1g a day, while the unfermented control feed increased 10.5g a day.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.44 no.4
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• pp.519-529
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• 2024

Vehicle toll discounts on private roads are categorized into two types: non-sunset and sunset. Sunset types refer to provisions in which all or part of a law loses its effect upon a specific legislator-set deadline. Vehicles eligible for 'sunset' discounts include cargo vehicles operating late at night and eco-friendly vehicles powered by electricity or hydrogen. Korean government has subsidized all reduced toll fees for vehicles classified as non-sunset types on private roads to operators, but no subsidies have been provided for toll reductions on sunset vehicles. The rapid increase in electric hydrogen vehicles escalates the burden of reduced toll revenue on private road operators. This study analyzed traffic volume and toll reduction data from eight private road operators nationwide as of the end of 2023 to propose the necessity and method of supporting sunset-type toll reduction subsidies. In 2022, the subsidy for non-sunset types amounted to 87.5 billion won, or 18.6 % of total traffic revenue. The toll exemption and reduction ratio under the concession agreement ranged from 4.0 % to 5.65 % of total traffic volume for each operator. Although the proportion of vehicles exempted from sunset traffic increased from 0.85 % in 2017 to 2.79 % in 2022, the reduction amount ratio reached 4.2 % (KRW 25.5 billion) of total traffic revenue in 2022. The escalating number of registered eco-friendly vehicles is gradually causing operating profit losses on private roads. In alignment with the government's policy to expand eco-friendly vehicles, it is imperative to consider including vehicles eligible for toll reductions listed under the sunset category for subsidy payments. The study established a minimum ratio for toll reduction assistance at 4.0 %, agreed upon between the road authorities and private operators. Three policy alternatives were proposed to ensure preservation of amounts exceeding this threshold for sustaining adequate toll revenue for private road operators.