• Proceedings of the Korea Water Resources Association Conference
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• 2011.05a
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• pp.402-402
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• 2011

식생의 성장은 수문순환과 밀접히 연관되어 있으며 특히 강수량은 식생의 연간변동성의 주된 요인이다. 하지만 국내의 경우 이러한 식생과 강수량과의 관계를 알아보기 위한 정량적인 접근은 시도되지 않은 실정이다. 순일차생산량(NPP)은 광합성으로부터 생성된 유기물질에서 성장에 필요한 호흡량을 뺀 것이며, 이는 식생량을 산정할 때 주로 이용된다. 본 연구에서는 우리나라 전역의 50 지역의 5년간의 NPP와 연강수량이 분석에 사용되었다. 비록 자료기간이 관계를 정립하기에는 다소 부족하며 NPP자료 자체의 불확실성이 내포되어 있지만 각 지점별 NPP와 강수량과의 상관성이 매우 높은 지역들이 있는 것으로( ��0.6) 나타났다. 하지만 모든 지역의 자료를 동시에 고려하였을 경우에는 결정계수가 크게 감소하였다($R^2$=0.310). 추가적으로 강우이용효율과 연강수량의 관계를 분석하였으나 결정계수가 0.022로 기존의 문헌과는 달리 이들 사이에 뚜렷한 관계가 나타나지는 않았다. 본 연구를 통하여 확인된 사실은 우리나라의 식생과 강수량 관계에서는 우리나라 전역을 전반적으로 설명할 수 있는 일반적인 선형 관계를 찾기는 힘들다는 것이며, 다만 지역별로 살펴볼 경우 식생-강수량 관계가 비교적 잘 맞는 지역들이 다수 존재한다는 것이다. 따라서 우리나라를 대상으로 한 생태적요소가 고려된 수문모형을 개발할 경우 지역적 특성들이 모형 구조에 반영되어야 할 것이다.

• Journal of Korea Foresty Energy
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• v.21 no.1
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• pp.25-31
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• 2002

This study was carried out to estimate aboveground biomass and net primary production in an average 37-year-old Quercus acutissima stand of Pohang area. Ten sample trees were cut in the forest and soil samples were collected in August, 2001. Estimation for aboveground biomass and net primary production was made by the equation model Wt=$aD^b$ where Wt is ovendry weight in kg and D is DBH in cm. Total aboveground biomass was 115.47ton/ha in the study forest. The proportion of each tree component to total aboveground biomass was high in order of bolewood(63.9%), branches(19.8%), bolebark(16.2%) and leaves(1.2%) in the study forest. Aboveground total net primary production was estimated at 7.89ton/ha in the study area. The proportion of each tree component to total net primary production was high in order of bolewood, bolebark, branch, and leaves.

• Journal of Korea Foresty Energy
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• v.17 no.1
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• pp.1-7
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• 1998

This study was to investigate the productivity of 24-year-old Larix leptolepis plantation in the Experimental Forest of Chungbuk National University located in Mt. Worak, Chungchungbuk-do, Korea. Eight plots(l0m x l0m) were established in the larch plantation in the 9th compartment. Eight sample trees were selected and cut off. Stem, branches and leaves were weighed respectively with the stratified clipping method, and analyzed for productive structure. The allometric regression equations between dry weight of each component(stem, branches. and needles) and D$^2$H were obtained. The results obtained are summarized as follows; (1) Photosynthetic layer of Larix leptolepis was shown at about 13m in height, and maximum needle amount of crown at 15-l6m in height. (2) The total biomass of aboveground was 186.25tons/ha(86.3% from stem, 9.9% from branches and 3.8% from needles). (3) Annual net production of aboveground was 12.17tons/ ha/yr, and the ratios of stem, branches and needles to that of aboveground, 0.835, 0.12, and 0.045, respectively.

• Korean Journal of Ecology and Environment
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• v.47 no.3
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• pp.167-175
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• 2014

This study was conducted to quantify a carbon budget of major vegetation types established in the campus of the National Institute of Ecology (NIE). Carbon budget was measured for Pinus thunbergii and Castanea crenata stands as the existing vegetation. Net Primary Productivity (NPP) was determined by applying allometric method and soil respiration was measured by EGM-4. Heterotrophic respiration was calculated as 55% of total respiration based on the existing results. Net Ecosystem Production (NEP) was determined by the difference between NPP and heterotrophic respiration (HR). NPPs of P. thunbergii and C. crenata stands were shown in $4.9ton\;C\;ha^{-1}yr^{-1}$ and $5.3ton\;C\;ha^{-1}yr^{-1}$, respectively. Heterotrophic respirations of P. thunbergii and C. crenata stands were shown in $2.4ton\;C\;ha^{-1}yr^{-1}$ and $3.5ton\;C\;ha^{-1}yr^{-1}$, respectively. NEPs of P. thunbergii and C. crenata stands were shown in $2.5ton\;C\;ha^{-1}yr^{-1}$ and $1.8ton\;C\;ha^{-1}yr^{-1}$, respectively. Carbon absorption capacity for the whole set of vegetation types established in the NIE was estimated by applying NEP indices obtained from current study and extrapolating NEP indices from existing studies. The value was shown in $147.6ton\;C\;ha^{-1}yr^{-1}$ and it was calculated as $541.2ton\;CO_2ha^{-1}yr^{-1}$ converted into $CO_2$. This function corresponds to 62% of carbon emission from energy that NIE uses for operation of various facilities including the glass domes known in Ecorium. This carbon offset capacity corresponds to about five times of them of the whole national territory of Korea and the representative rural area, Seocheongun. Considered the fact that ongoing climate change was originated from imbalance of carbon budget at the global level, it is expected that evaluation on carbon budget in the spatial dimension reflected land use pattern could provide us baseline information being required to solve fundamentally climate change problem.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.53 no.3
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• pp.339-346
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• 2008

The contents of starch, moisture, crude protein, crude fat, crude fiber, and ash of different varieties of various crops such as brown rice, barley, corn, sweet potato were analyzed. The average starch contents of brown rice, barley, corn, and sweet potato were $70.1{\pm}0.4\;{\sim}\;72.2{\pm}2.1$, $68.7{\pm}0.2\;{\sim}\;71.4{\pm}1.2$, $67.6{\pm}0.8\;{\sim}\;69.4{\pm}1.8$, and $21.7{\pm}0.9\;{\sim}\;28.3{\pm}0.5%$, respectively. The ground powder of each starchy substrate was suspended in distilled water, and then liquefied, saccharified, and fermented by dried active yeast at 32 for 4 days. By statistical analysis, the effectiveness of the contents of the different components such as starch, moisture, crude protein, crude fat, crude fiber, and ash of the crops on the ethanol production were examined. The results showed that the starch content positively affected the ethanol production in all the tested cereals and sweet potato. In brown rice, ash content affected negatively the ethanol production. In barley, protein content affected negatively the ethanol production, while fiber content affected positively the ethanol production. The sweet potato containing higher content of moisture produced less amount of ethanol.

• Journal of Wetlands Research
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• v.11 no.3
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• pp.61-70
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• 2009

Seasonal changes of flora, vegetation structure, and primary production for the vascular plants were investigated in the disturbed bank, Daedaejae, one of the reinforced bank of Upo wetland, in Changnyeong-gun, Gyeongsangnam-do, Korea from October 2005 to October 2006. The flora of the whole study area, the fabricated and the non-fabricated bank area were composed of 78, 72, 75 taxa, respectively. Among all of them, hydrophytes, hygrophytes, and mesophytes were 3, 33, and 42 taxa, respectively. The naturalized plants were 20 taxa, which was 25.6% of 78 taxa distributed in the study area. Dominant species of the fabricated and the non-fabricated bank area was Equisetum arvense and Trifolium repens, respectively. Importance values of the naturalized plants such as Erigeron annuus, Humulus japonicus, Astragalus sinicus and Ambrosia artemisiifolia var. elatior were relatively high in both area. The species diversity indices(H') were 1.010~1.450, and those were relatively high in October and low in March in both area. Those of the non-fabricated bank area was higher than the fabricated bank area during the whole study period. The similarity indices(CCS) between two kinds of banks were 0.359~0.456, and was lowest in March and highest in August, the culmination period of the vascular plants. Net primary production in the fabricated bank area was $417.1\;g/m^2$, and those of Phragmites communis, Oenothera odorata, Miscanthus sacchariflorus were 179.5, 84.0, and $66.1\;g/m^2$, respectively. Net primary production in the nonfabricated bank area was $392.7\;g/m^2$, and those of Erigeron canadensis, Miscanthus sacchariflorus, and Phragmites communis were 102.5, 87.4, and $81.6\;g/m^2$, respectively.

• Journal of Climate Change Research
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• v.4 no.2
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• pp.77-93
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• 2013

Global warming accelerates both carbon (C) input through increased forest productivity and heterotrophic C emission in forest soils, and a future trend in soil C dynamics is uncertain. In this study, the Korean forest soil carbon model (KFSC model) was applied to 1,467,458 ha of Pinus densiflora forests in Korea to predict future C dynamics under RCP 8.5 climate change scenario (RCP scenario). Korea was divided into 16 administrative regions, and P. densiflora forests in each region were classified into six classes by their stand ages : 1 to 10 (I), 11 to 20 (II), 21 to 30 (III), 31 to 40 (IV), 41 to 50 (V), and 51 to 80-year-old (VI+). The forest of each stand age class in a region was treated as a simulation unit, then future net primary production (NPP), soil respiration (SR) and forest soil C stock of each simulation unit were predicted from the 2012 to 2100 under RCP scenario and constant temperature scenario (CT scenario). As a result, NPP decreased in the initial stage of simulation then increased while SR increased in the initial stage of simulation then decreased in both scenarios. The mean NPP and SR under RCP scenario was 20.2% and 20.0% higher than that under CT scenario, respectively. When the initial age class was I, IV, V or VI+, predicted soil C stock under CT scenario was higher than that under RCP scenario, however, the countertrend was observed when the initial age class was II or III. Also, forests having a lower site index showed a lower soil C stock. It suggested that the impact of temperature on NPP was higher when the forests grow faster. Soil C stock under RCP scenario decreased at the end of simulation, and it might be derived from exponentially increased SR under the higher temperature condition. Thus, the difference in soil C stock under two scenarios will be much larger in the further future.

• 한국해양학회지
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• v.21 no.2
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• pp.73-84
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• 1986

Photometric Winkler titration provides high precision enough to use the oxygen method in moderately productive waters In short incubation (2-4hr), about $2{\mu\textrm{g}}C/\ell/h$ can be differentiated by the photometric titration. The oxygen and $^{14}C$ methods resulted in good agreement with each other in the diurnal primary production measurements. Despite small descrepancies the severe underestimation of $^{14}C-technique$ was not observed in short-term incubation. Size-fractionated production studies indicated the importance of nanoplanktonic production in the coastal water (62-88%). Bacterial respiration may lead to significant underestimation in estimating net photosynthesis in the oxygen method. In spite of some problems associated with the ecological application of antibiotics, it seems feasible to use Gentamycin in separating planktonic respiration from that of total community.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.23 no.3
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• pp.139-143
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• 2023

The product portfolio problem(PPP) is an optimization problem that determines the production quantity of a particular product to obtain the maximum profit among the n products. Linear programming(LP) is known as the only way to solve this optimization problem. The linear programming method is a problem that optimizes n linear functions and uses LINGO or Excel solver. This paper proposes a simple algorithm that uses CPR, a product cost-profit ratio, to sort in CPR descending order and then determines the maximum allowed production quantity by hand as the actual production quantity. As a result of applying the proposed algorithm to six experimental data, it was shown that more accurate results can be obtained compared to the linear programming method.

• Proceedings of the Korea Water Resources Association Conference
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• 2019.05a
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• pp.302-304
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• 2019

탄소 순환과 수문 순환의 관계를 이해하기 위해서는 효율적인 물 사용과 실제 물 사용 간의 비율로 정의되는 용수효율(Water Use Efficiency; WUE)을 정량화 하는 것이 필요하다. 특히 용수효율을 평가하기 위해서는 탄소 순환의 주요 인자인 총 1차 생산량(Gross Primary Productivity; GPP)과 순 1차 생산량(Net Primary Productivity; NPP)을 산정하는 것이 중요하다. 본 연구에서는 전 세계적으로 가장 많이 활용되고 있는 지면 모형 중 하나인 Community Land Model(CLM)을 활용하여 동아시아 지역에서의 GPP와 NPP를 산정하였다. 모형을 통해서 산정된 광역의 GPP와 NPP는 Flux tower에서 관측된 지점 자료를 활용하여 검증할 예정이다. 또한 지면 모형에서 획득한 동아시아 지역의 GPP와 NPP에 대한 공간 분포를 분석하여 탄소 순환 인자들에 대한 시공간적인 변화에 대하여 확인하고자 한다.