• Journal of Biosystems Engineering
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• 제36권2호
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• pp.122-129
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• 2011

This study was performed to develop a wireless system for measuring agricultural atmospheric factors using ubiquitous sensor network(USN). In the study, temperature, humidity and light intensity were selected and evaluated as major agricultural atmospheric factors. An USN system was designed and implemented by using Zigbex I and II (mote sensor nodes of MICA series) provided by Hanback Electronics, Korea. The system was tested in a greenhouse and an orchard. The experiment results showed that the suggested USN measuring system would be very effective on comprehensive measurement of the selected factors on the basis of time, day, spatial sequence with reasonable costs.

• Journal of Korean Society for Atmospheric Environment
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• 제23권E2호
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• pp.47-56
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• 2007

Among all the nitrogen species present in the atmosphere, ammonia forms a considerable portion along with the nitrogen oxides. The major sources of atmospheric ammonia are animal feedlot operations including emission from excreta of domestic animals and agricultural activities, followed by emission from synthetic fertilizers, biomass burning and to some lesser extent, fossil fuel combustion. Ammonia emission factor, expressed as the weight of ammonia per unit weight, volume, or duration of the activity emitting it, is generally used in developing emission estimates for emission inventories. The factors determining ammonia loss from soil or from manures are the temperature, pH, humidity, precipitation and the velocity of wind above it.

• 한국대기환경학회지
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• 제15권3호
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• pp.317-325
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• 1999

The demand of diesel engine on the construction equipment has been rapidly increased because of high thermal efficiency and fuel economy. The exhaust emission from nonroad vehicles equipped with diesel engine such as construction equipment, ship, and agricultural equipment, etc. Which are known to be harmful to human health and environment, has not been regulated in our country. But the regulation for nonroad vehicle has been already progressed in advanced country. So we investigated the contribution ratio of air pollution by construction equipment in order to establish the exhaust emission management strategy for nonroad vehicle. Based on the statistical data for construction equipment, 5 kinds of equipment are selected and tested in the engine dynamometer to determine the emission factor. And the amount of air pollutant from construction equipment are calculated by using of the emission factor and recommended exhaust emission standard for construction equipment.

• 한국잠사곤충학회지
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• 제49권2호
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• pp.51-55
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• 2007

기온, 강수량 등 기상요인이 누에에 미치는 영향을 조사하기 위해 뽕나무 재배조건, 토양, 기후조건이 다른 누에 우량교배조 지역적응시험 수행지인 전국 8개소를 대상으로 2006년 춘추잠기 양잠기상과 작황 영향 조사를 실시하였다. 2006년 춘추잠기 기상요소의 특징은 전국 평균 애누에때, 큰누에때, 섶중때의 기온은 각각 $17.7^{\circ}C$, $19.8^{\circ}C$, $21.5^{\circ}C$로 예년대비 평균 $1^{\circ}C$ 높았으며, 강수량은 각각 15.1mm, 6.9 mm, 7.0mm로 큰누에때와 설중때는 예년대비 평균 22.9 mm 적었다. 일조시수는 유충기간동안은 예년보다 1.7시간 짧았으나 설중때는 예년과 큰 차이 없었다. 즉, 예년대비 기온이 높고 강수량이 적어 가뭄현상을 보였던 2006년 춘잠기 작황은 예년에 비해 화용비율이 낮고, 수 견량이 약 1 kg 적었으며 전견중이나 견층비율은 다소 높았다. 추잠기 기상요소의 특징은 애누에때, 큰누에때, 설중때의 기온은 각각 $25.1^{\circ}C$, $20.5^{\circ}C$, $19.9^{\circ}C$로 예년대비 애누에때의 기온은 약 $1^{\circ}C$ 높았으며 큰누에때는 $1.3^{\circ}C$낮았다. 설중때는 거의 같은 수준을 보였다. 강수량은 각각 10.2mm, 4.6 mm, 3.7mm로 예년과 대비하여 큰 차이가 없었다. 즉, 예년과 비슷한 양상을 보였던 추잠기 기상은 2006년 추잠기 작황에도 별다른 영향을 주지 않았다. 즉, 전견중과 견층중은 예년과 큰 차이 없어 견층비율의 변화도 없었던 평작 수준이었다.

• 한국환경농학회지
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• 제35권4호
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• pp.302-305
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• 2016

BACKGROUND: The northeast district of China, especially Liaoning province, Jilin province, and Heilongjiang province, is one of the largest agricultural production regions in China. These regions play a significant role in ensuring food security. Accumulated temperature such as growing degree days (GDD) is an important environmental factor for plant growth and yield. Therefore, in this study, temporal and spatial distribution of GDD for maize was examined as a basis to estimate the growth and yield of maize in these regions. METHODS AND RESULTS: Meteorological date produced by NASA (MERRA-2) was used to estimate GDD of maize at this study sites. The GDD was calculated from sowing (May 1) to harvesting (Sep. 30). The average GDD of this region between 2010 and 2015 was $1323.0^{\circ}C$ day (595.3-1838.9). The spatial distribution of GDD showed a similar pattern during the different years surveyed. Double cropping for maize could be in only Liaoning province, northwestern Jilin province, and western and eastern Heilongjiang province where the GDD was over $1600^{\circ}C$day. However, The GDD in eastern Heilongjiang province was varied by year. CONCLUSION: The GDD of maize in northeast district of China was varied spatially, but similar among recent six years at the same region. This result can be used to predict growth stage and yield of maize at these regions.

• 한국대기환경학회지
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• 제31권1호
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• pp.63-71
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• 2015

The gaseous and particulate emissions from agricultural crop residues burning were investigated. The test residues included white soybean stem, pepper stem, apple branch, peach branch, pear branch, grape branch, sesame stem, perilla stem, and barley stem. Particulate emissions were dominated by fine particles (< $0.1{\mu}m$ in size). The highest $PM_{2.5}$ Emission factors were from barley stems (35.2 g/kg), and the lowest from pepper stems (7.9 g/kg). Emission factors for CO, NO, and VOCs were 146~305 g/kg, 4.94~15.02 g/kg, 27.4~353.3 g/kg, respectively. Benzene played an important role in VOCs emissions from biomass burning.

• 한국대기환경학회지
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• 제20권2호
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• pp.263-276
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• 2004

According to the annual emission estimates of U.S.A., fugitive dust, the particulate matter entrained in the ambient air which is caused from man-made or natural activities such as movement of soil, vehicles, equipments and windblown dust, contributes 90% of PM$_{10}$ emission. In spite of an importance of fugitive dust emission in PM$_{10}$ estimation, it is excluded in the national emission inventory of Korea so far. In this paper, an emission inventory of fugitive dust for each region and in major cities throughout the country, which is the first time in Korea these values have been compiled, is presented. Sources of fugitive dust emission have been classified into paved/unpaved roads, construction operations, agricultural operations, and natural sources. The emission factors of the existing fugitive dust emission were reassessed in a way that significantly improved the reliability of the estimated result. The Korea's first national emission inventory of fugitive dust by administrative districts proposed in this paper would provide scientific reference data for establishing an reduction strategy of PM$_{10}$ and preparing effective control measures, and would contribute to academic achievement in the atmospheric environments field and the establishment of CAPSS (Clean Air Policy Support System).stem).

• 농업과학연구
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• 제43권3호
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• pp.353-359
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• 2016

Soil organic carbon (SOC) retention has gradually gotten attention due to the need for mitigation of increased atmospheric carbon dioxide and the simultaneous increase in crop productivity. We estimated the statistical maximum value of soil organic carbon (SOC) fixed by clay content using the Korean detailed soil map database. Clay content is a major factor determining SOC of subsoil because it influences the vertical mobility and adsorption capacity of dissolved organic matter. We selected 1,912 soil data of B and C horizons from 13 soil series, Sangju, Jigog, Jungdong, Bonryang, Anryong, Banho, Baegsan, Daegog, Yeongog, Bugog, Weongog, Gopyeong, and Bancheon, mainly distributed in Korean upland. The ranges of SOC and clay content were $0-40g\;kg^{-1}$ and 0 - 60%, respectively. Soils having more than 25% clay content had much lower SOC in subsoil than topsoil, probably due to low vertical mobility of dissolved organic carbon. The statistical analysis of SOC storage potential of upland subsoil, performed using 90%, 95%, and 99% maximum values in cumulative SOC frequency distribution in a range of clay content, revealed that these results could be applicable to soils with 1% - 25% of clay content. The 90% SOC maximum values, closest to the inflection point, at 5%, 10%, 15%, and 25% of clay contents were $7g\;kg^{-1}$, $10g\;kg^{-1}$, $12g\;kg^{-1}$, and $13g\;kg^{-1}$, respectively. We expect that the statistical analysis of SOC maximum values for different clay contents could contribute to quantifying the soil carbon sink capacity of Korean upland soils.

• 한국농림기상학회지
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• 제11권4호
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• pp.233-246
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• 2009

증발산(ET)을 증발(E)과 증산(T)으로 배분하는 것은 물 순환과 에너지, 물 및 탄소 순환의 연결고리를 이해하는 데에 매우 중요하다. 산림 군락의 총 증발산은 상부 및 하부 군락의 증산과 토양 및 차단 강수로부터의 증발로 구성된다. 이들의 상대적 기여도를 정량화하기 위해, 에디 공분산 방법을 사용하여 2008년 6월 1일부터 2009년 5월 31일까지 광릉 활엽수림과 침엽수림의 마루에서의 증발산을 관측하였다. 스펙트럼 분석에 따르면, 초음파 풍향 풍속계와 수증기 농도 측정기 사이의 거리에 의한 증발산 과소 평가는 군락 하부에서 연간 증발산량의 약 10%정도였다. 하부군락의 연간 증발산은 활엽수림과 침엽수림에서 각각 59mm와 43mm로, 총 증발산량의 16%와 7%를 차지하였다. 전반적으로 식생면적지수가 최대인 여름 기간을 제외하고는 하부군락의 증발산은 총 증발산에서 무시할 수 없는 부분을 차지하였다. 두 산림지역의 비결합 모수($\Omega$)는 약 0.15이었으며, 이는 하부군락의 증발산이 주로 포차나 토양 수분에 의해서 조절됨을 보여준다. 두 산림의 하부 군락의 증발산의 차이는 군락 하부의 환경 조건의 차이에 기인하며, 특히 습도와 토양 수분의 차이로 인해 발생하였다. 광릉 하부 군락의 증발산 기여도가 작지 않다는 사실은 이러한 산림의 물질과 에너지 플럭스를 해석하고 모델링하기 위해서는 이원 또는 다층 모형이 필요함을 시사한다.

• 농약과학회지
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• 제10권2호
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• pp.91-98
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• 2006

일본의 시중 판매 및 노지재배 시금치 중 다이옥신 잔류함량을 평가하여 다이옥신 분석에 적정한 농산물 시료량을 검토함과 동시에 농작물과 재배환경 중 잔류함량 상관성에 대하여 다이옥신 동족체별로 비교 연구하였다. 1 Kg 미만을 처리한 시판되는 시금치의 OCDF은 베이스라인에 가깝게 검출되었으나, 2 kg 이상을 처리한 노지재배 시금치의 경우 확실하게 검출되었다. 시판 시금치 재배환경의 대기 중 다이옥신 동족체별 잔류함량 경향이 노지재배 시금치의 재배환경과 유사한 경향을 나타내므로, 정확한 다이옥신 peak 평가를 하기 위해서는 2 kg이상의 시료가 필요하다는 결과를 얻었다. 또한 노지재배 시금치 잎 중 다이옥신 동족체별 잔류함량의 전체 경향을 비교하면 토양에 분포하고 있는 OCDD와 HCDF의 영향을 받은 듯하나 전체적으로는 대기 강하물에 의한 영향이 주요 요인으로 판단된다.