• Title/Summary/Keyword: 교육공학

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A Study on Improvement of Air Quality Dispersion Model Application Method in Environmental Impact Assessment (II) - Focusing on AERMOD Model Application Method - (환경영향평가에서의 대기질 확산모델 적용방법 개선 연구(II) - AERMOD 모델 적용방법을 중심으로 -)

  • Suhyang Kim;Sunhwan Park;Hyunsoo Joo;Minseop So;Naehyun Lee
    • Journal of Environmental Impact Assessment
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    • v.32 no.4
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    • pp.203-213
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    • 2023
  • The AERMOD model was the most used, accounting for 89.0%, based on the analysis of the environmental impact assessment reports published in the Environmental Impact Assessment Information Support System (EIASS) between 2021 and 2022. The mismatch of versions between AERMET and AERMOD was found to be 25.3%. There was the operational time discrepancy of 50.6% from industrial complexes, urban development projects between used in the model and applied in estimating pollutant emissions. The results of applying various versions of the AERMET and AERMOD models to both area sources and point sources in both simple and complex terrain in the Gunsan area showed similar values after AERMOD version 12 (15181). Emissions are assessed as 24-hour operation, and the predicted concentration in both simple and complex terrain when using the variable emission coefficient option that applies an 8-hour daytime operation in the model is lowered by 37.42% ~ 74.27% for area sources and by 32.06% ~ 54.45% for point sources. Therefore, to prevent the error in using the variable emission coefficient, it is required to clearly present the emission calculation process and provide a detailed explanation of the composition of modeling input data in the environmental impact assessment reports. Also, thorough reviews by special institutions are essential.

Prospect of Sustainable Organic Tea Farming in Lwang, Kaski, Nepa (네팔 르왕지역의 지속적 유기농차 재배 방향)

  • Chang, K.J.;Huang, D.S.;Park, C.H.;Jeon, U.S.;Jeon, S.H.;Binod, Basnet.
    • Journal of Practical Agriculture & Fisheries Research
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    • v.12 no.1
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    • pp.137-150
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    • 2010
  • Traditionally, like many people in mountain region of the Himalaya, the Lwang communities depend on mix of subsistence agriculture, animal husbandry, and seasonal migrant labor for their livelihoods. These traditional systems are characterized by low productivity, diverse use of available natural resources (largely for home consumption), limited markets, and some aversion for innovation. The potential to generate wealth through commerce has largely been untapped by these mountain residents and thus is undervalued in local and national economies. Introduction of organic tea farming is a part of Lwang community's several initiatives to break the vicious poverty cycle Annapurna Conservation Area Project (ACAP) played facilitating roles in all their efforts since beginning. In five years, the tea plantation emerged as a new means for secured a livelihood. This study aims to analyze the current practices in tea farming both in terms of farm management and soil nutrient status(technical) and the prosperity of the tea farmers (social). The technical aspect covers the soil and tea leaf analysis of various nutrients contents in the soil and tea leaf. Originally, the technical aspect of the study was not planned but later during the consultation with the advisor it was taken into consideration which added value to the research study. The sample were collected from different locations and analyzed on the field itself. The other part of the study i.e. the social aspect was done through questionnaire survey and focus group discussion. the tea farming provided them not only a new opportunity but also earned an identity in the region. This initiative was undertaken as a piloting measure. Now that the tea is in production with processing unit established locally, more serious consideration has to be given for better yield and economic prosperity. This research finding will help the community to analyze their efforts and make correction measures in tea garden management and application of fertilizer. It is also expected to fill up the gaps of knowledge and information required to reduce economic stresses and enhance capacity of farmers to make the tea farming a sustainable and beneficial business. The findings are expected to Sustainability of organic tea farming has direct impacts on biodiversity conservation compared to the other traditional farming practices that are more resource intensive. The study will also contribute to identify key action points required for reducing poverty while conserving environment and enhancing livelihoods

The Effects on Yield, Fruit Characteristics and Growth caused by Low Temperature Treatment of Cucumber (Cucumis sativus L.) Seedling (오이묘의 저온처리가 생육, 과실특성 및 수량에 미치는 영향)

  • Nam, Y.I.;Woo, Y.H.;Hong, K.H.;Lee, K.H.;Suh, G.S.;Kim, J.K.
    • Journal of Practical Agriculture & Fisheries Research
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    • v.10 no.1
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    • pp.77-90
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    • 2008
  • This study was conducted to investigate the influence of chilling temperature and duration at different seeding stages on yield, fruit characteristics and growth of cucumber in a greenhouse. When 20-day-old cucumber were exposed to 0 and 3℃ for 10 hours, 25 and 30% reduction in the main stem elongation rate and 34 and 37% reduction in total leaf area per plant were observed. The reduction in stem elongation and total leaf area was apparently associated with the increases in chilling duration. Exposure of seedlings to 6℃ failed to causes any significant differences in growth as compared to the unchilled plants. Repeated exposure of seedlings to 3℃ chilling for 10 hours per day increased the chilling injury significantly. The seedlings exposed to low temperature for 3 consecutive days exhibited severe injury as compared to the seedlings exposed to chilling treatment only once or twice. Fruit elongation rate was inhibited by approximately 10%, such as 0.59~2.26cm/day, with chilling of 15 hours at 0℃ as compare to 0.61~2.60cm/day in the non-chilled plants. Chilling treatment at 0~3℃ for 10 hours reduced the percentage of marketable fruits by 25~26%. while it increased the percentage of severely bent fruits significantly. Total fruits yield was reduced by 15~25% in cucumber plants when the chilling treatment was given to 20-day-old seedlings and by 22~37% in 30-day-old seedlings. This shows that, Larger seedlings were more sensitive to chilling. Total yield was also influenced by the duration of chilling. Definitely, at 0℃, 5-hour chilling treatment caused 18% of reduction, 10-hour caused 30%, and 15-hour caused 36%, respectively.

Components and Pharmaceutical Effect of Beverage Extracted from Sugar-treated Tartary buckwheat (타타리메밀 당절임 추출음료의 성분 및 약리효능)

  • Park, J.J.;Chang, K.J.;Seo, G.S.;Lee, H.S.;Lee, G.S.;Park, C.H.;Lee, M.H.
    • Journal of Practical Agriculture & Fisheries Research
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    • v.10 no.1
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    • pp.67-75
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    • 2008
  • Tartary buckwheat is one of specialized plants in Pyeongchang county, Korea and contains rutin much more than common buckwheat. Rutin is a kind of flavonoid (polyphenol compound) that has effects on blood vascular disease, strengthen capillary, and anti-inflammatory effect. This study was conducted to determine the possibility of development of beverage extracted from sugar-treated plants and sprouts of tartary buckwheat. By using two types of undiluted solution extracted from plant and sprouts of tartary buckwheat, we analyzed their nutrition components and did experiment on mice to find out pharmaceutical effects. In an experiment on mice, we administered various concentration of buckwheat to induced diabetic mellitus mice for 1 weeks. As a result, the buckwheat effected finely on lowering blood sugar and decreased LDL-cholesterol and total lipid level but increased HDL-cholesterol level.

Effect of Side Openings and Greenhouse Width on the Natural Ventilation Performance (측창 및 온실 폭이 자연환기 성능에 미치는 영향)

  • Hyun Woo Lee;Young Hoe Woo;Jong Won Lee
    • Journal of Practical Agriculture & Fisheries Research
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    • v.25 no.1
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    • pp.14-19
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    • 2023
  • In summer, the natural ventilation performance for varying greenhouse width is very important in the glasshouses for year round cultivation. The effect of the side openings and greenhouse width on natural ventilation performance was analyzed by simulation. The necessary ventilation rate with different solar radiation transmittance increased significantly when the outside temperature grows higher. The necessary ventilation rate of 40% transmittance was about half of that of 90% transmittance. In consequence, shading effect on temperature control in greenhouse is significant in summer. When the total area of the openings for ventilation is constant, the maximum ventilation rate happens when the area of roof openings is equal to the area of side openings. This maximum ventilation rate is about 3 times of that of the greenhouse with roof openings and without side openings. Therefore, the side openings are advantageous to improve the natural ventilation in greenhouses. As the greenhouse width increases, the influence of side openings on the ventilation rate is becoming smaller. If the natural ventilation rate of the greenhouse with roof and side openings is to become double of that of the roof openings only, the width should be narrower than 38.4m for the Venlo type and 64m for Wide span type.

Comparison of the 2D/3D Acoustic Full-waveform Inversions of 3D Ocean-bottom Seismic Data (3차원 해저면 탄성파 탐사 자료에 대한 2차원/3차원 음향 전파형역산 비교)

  • Hee-Chan, Noh;Sea-Eun, Park;Hyeong-Geun, Ji;Seok-Han, Kim;Xiangyue, Li;Ju-Won, Oh
    • Geophysics and Geophysical Exploration
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    • v.25 no.4
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    • pp.203-213
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    • 2022
  • To understand an underlying geological structure via seismic imaging, the velocity information of the subsurface medium is crucial. Although the full-waveform inversion (FWI) method is considered useful for estimating subsurface velocity models, 3D FWI needs a lot-of computing power and time. Herein, we compare the calculation efficiency and accuracy of frequency-domain 2D and 3D acoustic FWIs. Thereafter, we demonstrate that the artifacts from 2D approximation can be partially suppressed via frequency-domain 2D FWI by employing diffraction angle filtering (DAF). By applying DAF, which employs only big reflection angle components, the impact of noise and out-of-plane reflections can be reduced. Additionally, it is anticipated that the DAF can create long-wavelength velocity structures for 3D FWI and migration.

Artificial Cultivation and Antioxidant Activity of Korean Native Mushroom Pycnoporus coccineus (한국산 간버섯의 인공재배 및 항산화 활성 평가)

  • Lee, Y.K.;Kim, M.K.;Yun, B.S.;Seo, G.S.
    • Journal of Practical Agriculture & Fisheries Research
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    • v.21 no.2
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    • pp.35-47
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    • 2019
  • The mycelial growth of P. coccineus strain was good in PDA and YMA, but mycelial growth was low in MEA. Light irradiation during the incubation period affected the pigment formation and density of mycelia. Mushroom of P. coccineus strain was able to produce fruiting bodies in both bottle and bag cultivation, and oak sawdust was found to be the most suitable substrate for spawn culture and cultivation. In artificial cultivation using sawdust medium, fruiting body was grown to the extent that visual observation was possible from the 15th day, and it formed about 5 days fast in the treatment group with low relative humidity. From 40 to 45 days of mushroom development, mature fruiting bodies could be harvested, and the lower relative humidity of the growing room favored mushroom development and growth. Antioxidant activity of fruiting bodies harvested from artificial cultivation showed that ABTS radical scavenging activity of bottle-cultivated and wild fruit bodies were shown at 505㎍/㎖ and 515㎍/㎖, respectively. However, fruiting bodies harvested in bag cultivation were high at 910㎍/㎖. As a result of DPPH radical scavenging activity, all extracts were found to be inactive, exhibiting IC50 value of more than 2,000㎍/㎖ concentration. The ethyl acetate extract of mushrooms obtained from bottle cultivation showed the highest activity with 1,550㎍/㎖ IC50 value. Methanol extract of wild fruit bodies had the highest ABTS radical scavenging activity at the same concentration (10mg/㎖).

Effects of Blueberry on the Quality Characteristics of Strawberry Jam (블루베리를 첨가한 딸기잼의 품질 특성)

  • Han, B.K.;Kang, C.S.
    • Journal of Practical Agriculture & Fisheries Research
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    • v.21 no.2
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    • pp.15-25
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    • 2019
  • The effect of blueberries on the quality characteristics of strawberry jam substituted with 50% sugar, glucose syrup 10% was investigated. Strawberry jams with 5, 10 and 20% blueberries in place of strawberry were prepared and evaluated for moisture content, reducing sugar, total acidity, pH, color, total sugar (°Brix), pectin content, anthocyanin content, DPPH radical scavenging activity, texture analysis and sensory characteristics. As the amount of blueberries increased, total acidity, °Brix , reducing sugar content and anthocyanin content of jams increased, while pH decreased, moisture content has changed little. The DPPH radical scavenging activities of the 80% methanol extract from jams were 75.33%, 85.75%, 91.23% and 92.73% at a concentration of 8 mg/mL. Radical scavenging activity increased with the added concentration of blueberries. The lightness decreased with addition of blueberries, but the redness and yellowness increased. The sensory scores for jams increased with the increase of blueberry content; however, strawberry jams with 10% blueberries showed the best scores.

Selection Method for Installation of Reduction Facilities to Prevention of Roe Deer(Capreouls pygargus) Road-kill in Jeju Island (제주도 노루 로드킬 방지를 위한 저감시설 대상지 선정방안 연구)

  • Kim, Min-Ji;Jang, Rae-ik;Yoo, Young-jae;Lee, Jun-Won;Song, Eui-Geun;Oh, Hong-Shik;Sung, Hyun-Chan;Kim, Do-kyung;Jeon, Seong-Woo
    • Journal of the Korean Society of Environmental Restoration Technology
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    • v.26 no.5
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    • pp.19-32
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    • 2023
  • The fragmentation of habitats resulting from human activities leads to the isolation of wildlife and it also causes wildlife-vehicle collisions (i.e. Road-kill). In that sense, it is important to predict potential habitats of specific wildlife that causes wildlife-vehicle collisions by considering geographic, environmental and transportation variables. Road-kill, especially by large mammals, threatens human safety as well as financial losses. Therefore, we conducted this study on roe deer (Capreolus pygargus tianschanicus), a large mammal that causes frequently Road-kill in Jeju Island. So, to predict potential wildlife habitats by considering geographic, environmental, and transportation variables for a specific species this study was conducted to identify high-priority restoration sites with both characteristics of potential habitats and road-kill hotspot. we identified high-priority restoration sites that is likely to be potential habitats, and also identified the known location of a Road-kill records. For this purpose, first, we defined the environmental variables and collect the occurrence records of roe deer. After that, the potential habitat map was generated by using Random Forest model. Second, to analyze roadkill hotspots, a kernel density estimation was used to generate a hotspot map. Third, to define high-priority restoration sites, each map was normalized and overlaid. As a result, three northern regions roads and two southern regions roads of Jeju Island were defined as high-priority restoration sites. Regarding Random Forest modeling, in the case of environmental variables, The importace was found to be a lot in the order of distance from the Oreum, elevation, distance from forest edge(outside) and distance from waterbody. The AUC(Area under the curve) value, which means discrimination capacity, was found to be 0.973 and support the statistical accuracy of prediction result. As a result of predicting the habitat of C. pygargus, it was found to be mainly distributed in forests, agricultural lands, and grasslands, indicating that it supported the results of previous studies.

Case Studies of Site Investigation Factors and Methods for Site Selection for High-Level Radioactive Waste Disposal (고준위방사성폐기물 처분 부지선정을 위한 조사인자 및 조사기법에 대한 국외사례 분석)

  • Hyo Geon Kim;Si Won Yoo;Dae Seok Bae;Soo Hwan Jung;Ki Su Kim;Jun Kyum Kim;Man Ho Han;Junghae Choi
    • The Journal of Engineering Geology
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    • v.33 no.4
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    • pp.611-626
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    • 2023
  • Overseas examples of the characterization stage of site selection proposed by the International Atomic Energy Agency were reviewed to highlight the factors necessary for consideration in the deep disposal of high-level radioactive waste. Studies in Sweden, Finland, the USA, and Canada were considered. Site investigations in Sweden and Finland commonly covered the fields of geology, hydrogeology, and hydrogeochemistry using similar field investigation techniques. The USA considered survey groups and factors under pre- and post-lockdown guidelines, as well as those for desaturated and saturated surveys. involving geophysical, hydrological, hydrogeological, hydrogeochemical, mechanical/physical, and thermal-characterization investigations. Canada provided a list of investigative methods for both preliminary and detailed site assessments including geological, physical, boring, hydrological, laboratory testing, and chemical analysis studies. Results of this study should elucidate site-selection investigation factors and survey methods applicable to Korea.