• Solar Energy
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• v.17 no.3
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• pp.67-73
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• 1997

In order to development of a new wall structure type thermal diode for energy saving, the numerical studies have been performed for natural convection across an rectangular enclosure with the various lengthes of the heat source and sink plate. The governing equations for the two-dimensional, laminar, natural convection process in an enclosure are discretized by the control volume approach which insures the conservative characteristics to be satisfied in the calculation domain, and solved by a elliptic SIMPLE algorithm. The momentum and energy equations are coupled through the buoyancy term.

• Journal of The Korean Society of Grassland and Forage Science
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• v.31 no.2
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• pp.167-176
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• 2011

본 연구는 우분액비의 시용이 경사도를 달리한 사료용 옥수수 재배지에서 옥수수의 생산성 및 유거수 중의 N의 유실에 미치는 영향을 조사하기 위하여, 건국대학교 축산대학 사료작물 시험포 내 설치된 Erosion apparatuses (가로 0.33 m, 세로 3 m, 깊이 0.4 m)를 이용하여 수행하였다. 시험구의 경사도는 0%, 8.75%, 17.50%로 하였으며, 우분액비는 6개월 이상 부숙된 것으로 질소 기준 200 kg/ha 시용하였다. 옥수수의 건물생산성과 사료가치는 경사도에 의해 영향을 받았으며, 17.50% 경사지의 건물생산성은 0% 경사지의 건물생산성에 비해 유의적인 감소를 보였다 (P<0.05). 유거수 중의 평균 $NO_3^--N$과 $NH_4^+-N$의 농도는 경사가 높아질수록 유의적으로 증가하였다(P<0.05). 이상의 결과에서 보는 바와 같이 우분액비를 시용하여 사료용 옥수수를 재배할 경우, 경사도가 증가할수록 그리고 집중호우가 발생할 경우에 유거수 중의 양분 유실량은 증가가 예상되기 때문에 경사도가 심한 지역에서 옥수수를 재배할 때에는 양분유실에 따른 수질오염을 고려하여 사료작물 재배 방법이 모색되어야 한다.

• Proceedings of the Korea Water Resources Association Conference
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• 2020.06a
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• pp.222-222
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• 2020

급격한 기후변화와 도시화, 산업화로 인해 도시지역의 홍수피해가 증가하고 있다. 기후변화로 인한 재해 중 45%가 극한 강우 또는 홍수로 인한 재해로 확인되었으며, 급속도로 확장되고 있는 도시화 추세로 인해 도시지역의 홍수피해가 더욱 심화되고 있다(UNISDR, 2016). 기후변화 및 도시화로 인한 도시지역의 홍수피해가 증가하면서 시가지 건물 배치 및 도로망과 같은 복잡한 지역특성이 침수에 주는 영향을 분석할 필요성이 점차 증가하고 있다. 도시지역에서 홍수가 발생할 경우 복잡한 도로망은 배수로 역할을 하며 건물의 밀집도와 배치는 골목길 등에서 침수심을 증가시켜 안전한 구역이 좁아지는 효과를 발생시키고 있다. 본 연구에서는 우선 복잡한 시가지를 특성화하여 분석 할 수 있도록 이상화된 시가지 모형을 설계하고 제작한 후 유량에 따른 흐름 특성 변화를 분석하였으며, 기초 실험 결과를 바탕으로 강우강도에 따른 유황 변화와 연계할 예정이다. 기초 실험 수행을 위하여 먼저 건물 배치 밀집도를 고려하여 주거구역을 불록화하여 직선형의 이상적인 도시지역의 시가지 모형을 설계한 후 실험 모형을 제작하였다. 하천 범람으로 인한 침수발생을 재현하기 위해 상류 도로망에서 유량이 유입되도록 제작하였으며, 유입조건에 따라 변화하는 시가지 내부 침수 흐름은 LSPIV 기법을 이용하여 분석하였다. 유입조건에 따른 시가지 내 침수 특성을 분석한 결과 지형적 경사 특성에 의해 시가지 내부에서 흐름이 가속되며, 모형의 사거리 구간에서는 흐름 유입 방향에 대해 횡방향으로 흐름이 합류하는 경우에는 합류 흐름이 유속이 더 높은 것으로 분석되었다. 따라서 합류 이후 유속이 증가하면서 피해 발생 가능성이 높은 것으로 나타났다.

• Journal of The Korean Society of Grassland and Forage Science
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• v.4 no.3
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• pp.180-186
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• 1984

From June, 1980 to October, 1982, this study was carried out to find an optimal grazing system on the timothy and orchardgrass-dominated pasture. Five different systems consisted of set stocking, modified set stocking, rotational grazing, 'wye college' system and zero grazing have been applied. The results obtained were as follow: 1. Herbage DM yield per ha with 'wye college' system, set stocking, modified set stocking, rotational grazing and zero grazing were 6936.7 kg,6794.3 kg, 6686.9 kg 6675.7 kg and 5083.4 kg respectively. Among treatments were not different in DM yield. 2. In herbage utilization, zero grazing was the highest than other. Zero Grazing, Rotational grazing, 'Wye college' system, Modified set stocking and set stocking was 89.3%, 70.8%, 64.4% and 46.1% respectively. 3. Daily intake per head with 'wye college' system was the highest than others and zero grazing was the lowest than others. 4. Daily gain with 'wye college' system, rotational grazing, modified set stocking, set stocking and zero grazing were 0.60kg, 0.55kg, 0.50kg, 0.43kg and 0.42 respectively. Among treatment, there was no significance. 5. Total weight gain per ha with 'wye college' system, rotational grazing, modified set stocking, zero grazing and set stocking were 339.5kg, 299.1kg, 253.3kg, 226.6kg and 222.2kg respectively. 6. Grazing time among treatments was not significant. 'Wye college' system spent the shortest time, 367.3 minutes and set stocking consumed the longest time, 422.1 minutes. 7. Daily grazing time by seasonal change with June, July, August, September and October was 304.9 min., 359.4 min., 437.9 min., 483.3 min. and 395.8 min., respectively. According to passing the season, grazing time was lengthened. 8. Grazing time for Korean native cow, native cow charolais and native cow holstein were not significant. Native sow charolais consumed the longest time, 457.0 min., whereas Korean native cow consumed the shortest time, 422.4 min..

• Journal of The Korean Society of Grassland and Forage Science
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• v.26 no.1
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• pp.15-24
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• 2006

This study was conducted to make a rapid and easy determination for the fertility of liquid pig manure as fertilizer by investigating the contents, and correlation coefficients of various nutrients. Samples were collected from 118 local pig farms in the western area of Jeju in Korea. Electrical conductivity(EC), dry matter(DM), $NH_4-N$ and minerals were determined and the relationships among them were examined. The collected liquid manure samples from 118 pig farms were classified according to the level of DM contents ;< 3% (92 farms), $3{\sim}6%$ (18 farms), $6{\sim}9%$ (5 farms) and>9% (3 farms), based on the collected data, most of the liquid manure coming from the local pig farms contain small amount of dry matter. The dry matter contents appeared highly correlated(p<0.01) with EC, $NH_4-N$, T-P, Ca, Mg and Na, except for K. In addition EC was proportional to $NH_4-N$, T-P, Ca, and Na except fer Mg. The fertilizer component ratio of $NH_4-N$, P and K in liquid pig manure were not constant, resulting in low efficiency for fertilizer. However, the toxic heavy metals of Cu etc. were below the criteria of organic fertilizer and soil contamination evaluation. Therefore, we concluded that both dry matter content and electrical conductivity could be used as an indicator for evaluating the fertility of liquid pig manure.

• Journal of the Korean Wood Science and Technology
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• v.43 no.6
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• pp.876-883
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• 2015

Han-green project, which pursues Korean style post and beam timber house with traditional construction technique of Han-ok, has been carried out in KFRI (Korea Forest Research Institute) since 2006. Recently, the improvement of its building energy performance was studied with energy-saving elements. This study was conducted to provide the insulation details of building envelopes in a post-beam timber house for recent enhanced insulation standards and following effect on building energy performance. The level of thermal transmittance (U-value) values of building envelopes was composed of two stages: present Korean insulation standards and passive house. To evaluate building energy performance, the building airtightness values of two stages was ACH50 = $3.0h^{-1}$ for common domestic timber house constructed recently, and ACH50 = $0.6h^{-1}$ for passive house. Consequently, four cases of the building energy performance according to the combination of U-value with airtightness were evaluated. The test house for evaluation was located in Seoul and its energy performance was evaluated with CE3 commercial building energy simulation program. The result showed that enhanced insulation from level I to II reduced $14kWh/(m^2{\cdot}a)$ of annual heating energy demand regardless of airtightness.

• Korean Architects
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• no.4 s.408
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• pp.78-83
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• 2003

건축사협회에서 마련했던'지구단위계획제도의 이해와 실습' 강좌에서 마지막 실습부문을 진행한 내용을 소개하고자 한다. 강좌를 진행하면서 느꼈던 점은 건축사들이 도시계획과 도시설계를 자기업무로 보지 않는다는 점을 다시 한번 확인한 것이다. 우리가 속해서 경쟁하고 있는 국제건축가연맹(UIA)의 이념과 목적을 보면 건축가의 사명을 '건축과 도시 계획을 발전시켜 공동체의 개선을 꾀할 것'이라고 천명하고 있다. 본고가 이러한 사명감에 따른 매뉴얼을 지닌 외국건축사들과 경쟁 또는 협력해야 할 우리 건축사들의 관념적 지평을 넓히는데 도움이 되었으면 한다. 2회에 나누어 실게 될 본고 중 지난호에는 지구단위계획과 건축설계와의 관계를 다루었다. 현재 우리의 구분기술 환경속에서 이 주제를 압축한다면 계획가와 설계기간의 연계 '바톤'이 곧 지구단위계획이 될 것이다. 그 속에는 건물이 넘어가서는 안되는 윤곽선과 용도 등이 들어있는 것이다. 이번 호에는 지구단위계획의 입안관점과 사례들을 소개한다.

• Korean Architects
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• no.3 s.407
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• pp.72-77
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• 2003

건축사협회에서 마련했던'지구단위계획제도의 이해와 실습' 강좌에서 마지막 실습부문을 진행한 내용을 소개하고자 한다. 강좌를 진행하면서 느꼈던 점은 건축사들이 도시계획과 도시설계를 자기업무로 보지 않는다는 점을 다시 한번 확인한 것이다. 우리가 속해서 경쟁하고 있는 국제건축가연맹(UIA)의 이념과 목적을 보면 건축가의 사명을 '건축과 도시 계획을 발전시켜 공동체의 개선을 꾀할 것'이라고 천명하고 있다. 본고가 이러한 사명감에 따른 매뉴얼을 지닌 외국건축사들과 경쟁 또는 협력해야 할 우리 건축사들의 관념적 지평을 넓히는데 도움이 되었으면 한다. 2회에 나누어 실게 될 본고 중 이번호에는 지구단위계획과 건축설계와의 관계를 다루고 있다. 현재 우리의 구분기술 환경속에서 이 주제를 압축한다면 계획가와 설계기간의 연계 '바톤'이 곧 지구단위계획이 될 것이다. 그 속에는 건물이 넘어가서는 안되는 윤곽선과 용도 등이 들어있는 것이다. 다음 호에는 지구단위계획의 입안관점과 사례들을 소개할 예정이다.

• Korean Journal of Weed Science
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• v.8 no.3
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• pp.317-323
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• 1988

This survey was conducted to know characterization of weed occurrence under protected culture conditions at Yousong in 1985. Chenopodium album, Polygonum hydropiper, Portulaca oleracea and Digitaria sanguinalis were dominated in outdoor, whereas Capsella bursa-pastoris, C. album, D. sanguinalis and P. oleracea were dominant in polyethylene house. More weeds emerged in mulching plots and dry weight of weeds was greater in non-mulching plots. Summer broadleaf weeds and summer grasses were abundant in outdoor, whereas non-mulching plots in polyethylene house was dominated by winter broadleaf weeds, and mulching plots in polyethylene house were dominated by winter grasses and winter broadleaf weeds in early stage and summer grasses and summer broadleaf weeds in late stage. Simpson index was high in polyethylene house and Shannon's diversity index, maximum diversity for the Shannon diversity index were lower than eveness using the Shannon diversity index and this trend was more remarkable in mulching and mulching in tunnel than in non-mulching under polyethylene house condition. Shannon diversity index, maximum diversity for the Shannon diversity index were high in mulching or tunnel, and Simpson index was high in non-mulching in outdoor condition. Interspecific competition was more severe than intraspecific competition in both conditions.

• Korean Journal of Agricultural Science
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• v.7 no.1
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• pp.27-32
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• 1980

In order to determine the effect of activated carbon on toxicity of linuron and napropamide to Chinese cabbage, red pepper, and tomatoes, 5 and 10kg/10a of activated carbon were applied to the soil surface prior to treatment of linuron at 50 and 75g/10a and napropamide at 150 and 225g/10a. 1. Chinese cabbage was protected from linuron injury by spraying activated carbon on the soil to adsorb and detoxify the herbicides even though it was completely killed by linuron at 50 and 75g/10a without activated carbon application. However, Chinese cabbage was not injured by napropamide at 150 and 225g/10a and thus antidotal effect by activated carbon was negligible. 2. Red pepper was greatly injured by linuron at 50 and 75g/10a, but activated carbon significantly reduced linuron injury. Napropamide at 225g/10a was slightly injurious to red pepper. Nevertheless, this injury effect was reduced by activated carbon at 5kg/10a. 3. Tomatoes were also severely injured by linuron at 75g/10a, but activated carbon prevented linuron injury to tomatoes. However, napropamide at 150 and 225g/10a were slightly injurious to tomatoes and activated carbon did not completely prevent napropamide injury to tomatoes.