• Journal of Korean Society of Forest Science
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• v.9 no.1
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• pp.61-74
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• 1969

Forest area in Korea ocupies as much as 68 percent of the total land area, but forest production figure in the statistics is rather trifling: that is about 2 percent of Gross National Production (G.N.P.), on the average. In view of the primary industrial sector, its production only weighs no more than 5 percent of this whole sector. Forest production written above refers only to direct forest income of the whole forest income. For the primary forest products they are in many cases used as raw materials for other interrelated industries. The added value there-from, which arises from round about production Process, in other word, indirect income is of most singnificance. Nevertheless, until nowadays forest production has been merely refered to timber production i, e, direct production but indirect income has never been looked upon. In this regard, calculated indirect forest income by means of input ratio method. The material used were Leontiefls tables of two 1963 and 1966 fiscal years, surveyed and analysed by The Bank of Korea. Indirect forest income calculated were 42,688,200,000 won in 1963 and 74,789,800,000 won in 1966 compared direct forest income of 14,361,000,000 won in 1963 and 17,709,000,000 won in 1966. So far as indirect forest income is considered total forest production indices composed of direct and indirect forest income amount to 8.23% in 1963 and 10.12% in 1966 of Gross National Production. Invisuable forest income which originates from, what we cal, indirect benefit of forestry such as land conservation, flood and drought control, soil run off control, scenic beauty and many others is naturall, not included in the calculation. As already mentioned, primary forest products are, for the most part, utilized as raw materials for other industries, therefore indirect forest income is rather appreciable than direct forest income, contributing for the growth and development of other connected industries. In these points of view, forestry must not be evaluated trifling in deciding industrial importances.

• Proceedings of The Korean Society of Agricultural and Forest Meteorology Conference
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• 2017.11a
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• pp.86-87
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• 2017

• Proceedings of The Korean Society of Agricultural and Forest Meteorology Conference
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• 2019.08a
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• pp.154-154
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• 2019

• Proceedings of the Korea Water Resources Association Conference
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• 2023.05a
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• pp.191-191
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• 2023

기후변화 대응을 위한 탄소 중립의 중요성이 대두되는 요즘, 생태계의 가장 큰 메탄 저장소로서 지구의 탄소 순환에 주요한 영향을 미치는 습지에 대한 이해는 필수적이다. 전지구 지면 모델인 Community Land Model(CLM)에 Functionally Assembled Terrestial Ecosystem Simulator(FATES) 외부 모듈을 함께 구동한 지면 생태계 모델 CLM-FATES는 지면 heterogeneity와 다양한 식생 종류를 고려하여 에너지 플럭스, 토양 수문, 생화학적 과정 등을 모의함으로써 탄소 동태 변화를 포함한 장기적 생태계 동태 변화 모의를 가능하게 한다. 본 연구는 CLM-FATES 모델을 미국 캘리포니아주 Mayberry Wetland (US-Myb)와 Twitchell East End Wetland (US-Tw4)에 적용하였다. 모델의 대기 입력 자료로는 FLUXNET-CH4에서 제공하는 에디 공분산 기반 플럭스 관측 자료를 사용하였다. 기존 CLM-FATES 모델은 토양이 장기간 포화 혹은 침수되어 지표 위 혹은 지표면 가까이 발달한 지하수면을 가지고 있는 습지의 수문학적 특성을 잘 반영하지 못해 정밀한 습지 생태계 동태 변화 모의에 한계를 가지고 있다. 본 연구에서는 CLM-FATES를 통한 보다 정확한 습지 생태계 모의를 위해 모델 내 토양 수문 관련 모듈을 수정하여 모델이 습지의 수문학적 특성을 반영할 수 있도록 하였다. 모델 구동 결과 도출한 잠열, 총일차생산량(Gross Primary Production: GPP)과 순생태계생산량(Net Ecosystem Production, NEP) 플럭스, 메탄 플럭스, 엽면적지수(Leaf Area Index; LAI)와 지표수 높이에 대해 관측값 대비 RMSE 및 R² 값을 계산하여 모의 결과의 적절성을 분석하였다. 이러한 모델 개선 경험을 바탕으로 추후 우리나라 습지 사이트에 모델을 적용하여 습지 탄소 동태 예측에 활용할 계획이다.

• Asian-Australasian Journal of Animal Sciences
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• v.31 no.7
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• pp.992-1006
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• 2018

Beef production extends over almost half of Australia, with about 47,000 cattle producers that contribute about 20% ($A12.7 billion gross value of production) of the total value of farm production in Australia. Australia is one of the world's most efficient producers of cattle and was the world's third largest beef exporter in 2016. The Australian beef industry had 25 million head of cattle in 2016-17, with a national beef breeding herd of 11.5 million head. Australian beef production includes pasture-based cow-calf systems, a backgrounding or grow-out period on pasture, and feedlot or pasture finishing. Feedlot finishing has assumed more importance in recent years to assure the eating quality of beef entering the relatively small Australian domestic market, and to enhance the supply of higher value beef for export markets. Maintenance of Australia's preferred status as a quality assured supplier of high value beef produced under environmentally sustainable systems from 'disease-free' cattle is of highest importance. Stringent livestock and meat quality regulations and quality assurance systems, and productivity growth and efficiency across the supply chain to ensure price competiveness, are crucial for continued export market growth in the face of increasing competition. Major industry issues, that also represent research, development and adoption priorities and opportunities for the Australian beef industry have been captured within exhaustive strategic planning processes by the red meat and beef industries. At the broadest level, these issues include consumer and industry support, market growth and diversification, supply chain efficiency, productivity and profitability, environmental sustainability, and animal health and welfare. This review provides an overview of the Australian beef industry including current market trends and future prospects, and major issues and opportunities for the continued growth, development and profitability of the industry.

• Food Science and Preservation
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• v.16 no.4
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• pp.490-498
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• 2009

This study attempted to examine the profitability and marketing costs of seed potato under contract farming system of BADC (Bangladesh Agricultural Development Corporation) with the help of primary and secondary data. Total 45 contract farmers were randomly selected. Attempts were made to calculate costs, returns and profitability of seed potato production under contract farming system, and to identify marketing channels of seed potato. The field level data were collected by a farm survey during the months of April 2005 through direct interviews with contract farmers and registered dealers using a structure survey questionnaire. The results showed that the gross return per hectare was Tk. 252,464 for all categories of farms. Cost of seeds, fertilizers, pesticides, irrigation and human labor were critical inputs for profitability of seed potato. Cobb-Douglas production function analysis was used to determine the effects of the key variables to seed potato production under contract farming system. The elasticity of seed potato production was at 0.727 for all categories of farms. The findings exhibited that the summation of elasticity of different inputs for seed potato production was less than one, implying that the production function exhibited decreasing returns to scale. Registered dealers and Upazila Sales Centers were involved in seed potato marketing formed a straightforward marketing channel. The total marketing costs of registered dealers were Tk. 759.49 per ton of seed potato. The net marketing margin of registered dealers was estimated at Tk. 465.51 per ton of seed potato. The selected contract farmers and registered dealers faced a number of problems and some of recommendations were suggested.

• Korean Journal of Remote Sensing
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• v.35 no.6_2
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• pp.1117-1132
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• 2019

Forest covers 30% of the Earth's land area and plays an important role in global carbon flux through its ability to store much greater amounts of carbon than other terrestrial ecosystems. The Gross Primary Production (GPP) represents the productivity of forest ecosystems according to climate change and its effect on the phenology, health, and carbon cycle. In this study, we estimated the daily GPP for a forest ecosystem using remote-sensed data from Moderate Resolution Imaging Spectroradiometer (MODIS) and machine learning algorithms Support Vector Machine (SVM). MODIS products were employed to train the SVM model from 75% to 80% data of the total study period and validated using eddy covariance measurement (EC) data at the six flux tower sites. We also compare the GPP derived from EC and MODIS (MYD17). The MODIS products made use of two data sets: one for Processed MODIS that included calculated by combined products (e.g., Vapor Pressure Deficit), another one for Unprocessed MODIS that used MODIS products without any combined calculation. Statistical analyses, including Pearson correlation coefficient (R), mean squared error (MSE), and root mean square error (RMSE) were used to evaluate the outcomes of the model. In general, the SVM model trained by the Unprocessed MODIS (R = 0.77 - 0.94, p < 0.001) derived from the multi-sites outperformed those trained at a single-site (R = 0.75 - 0.95, p < 0.001). These results show better performance trained by the data including various events and suggest the possibility of using remote-sensed data without complex processes to estimate GPP such as non-stationary ecological processes.

• Korean Journal of Agricultural and Forest Meteorology
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• v.16 no.2
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• pp.137-145
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• 2014

Rice-barley double cropping system is typical in southwestern part of South Korea. However, the information of carbon dioxide ($CO_2$) exchange for barley growing season has still limited in comparison with rice. Using the eddy covariance (EC) technique, seasonal variation of $CO_2$ exchange was analyzed for the barley growing season at a rice-barley double cropping field in Gimje, Korea. The effects of environmental factors and biomass on the $CO_2$ flux also were investigated. Quality control and gap-filling of flux data were conducted before this analysis and investigation. The results indicated that $CO_2$ uptake increased rapidly at tillering stage and maximum net ecosystem exchange of $CO_2$ (NEE) occurred at the early of May, 2012 ($-11.2gCm^{-2}d^{-1}$), when the heading of barley occurred. NEE, gross primary production (GPP), and ecosystem respiration (Re) during the barley growing season were -348.0, 663.3, and $315.2gCm^{-2}$, respectively. In this study, an attempt has been made to measure NEE, GPP, and Re with the help of the EC system for the barley growing season for the first time in Korea, focusing on $CO_2$ exchange between the biosphere and the atmosphere.

• Korean Journal of Agricultural and Forest Meteorology
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• v.15 no.4
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• pp.273-281
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• 2013

Based on the results of continuous flux measurements at the Gimje paddy flux site in the southwestern coast of Korea, carbon dioxide and energy exchanges between customarily cultivated rice-barley double cropping paddy field and the atmosphere during the 2012 rice growing season (from $9^{th}$ Jun. 2012 through $20^{th}$ Oct. 2012) were analyzed. Carbon dioxide and energy (H, LE) fluxes were estimated by the eddy covariance method. Environmental parameters (net radiation, precipitation, etc.) and plant biomass (LAI, plant height, etc.) were measured along with fluxes. After the quality control and gap-filling, the observed fluxes were analyzed. The results have been showed that net ecosystem exchange (NEE), gross primary production (GPP), and ecosystem respiration (Re) during the rice cropping period were -277.1, 710.3, and 433.2 g C $m^{-2}$, respectively.

• Journal of Korea Water Resources Association
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• v.54 no.10
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• pp.779-793
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• 2021

Water stress and environmental drivers are important factors to explain the variance of gross primary production (GPP). Environmental drivers are used to generate GPP in Moderate Resolution Imaging Spectroradiometer (MODIS) algorithm and process-based model. However, MODIS algorithm only consider the vapor pressure deficit (VPD) data while the process-based biogeochemical model also uses limited data to express water stress. We compared the relationship between environmental drivers and GPP from eddy covariance method, MODIS algorithm, and Community Land Model 4 (CLM 4) simulation in normal years and drought years. To consider water stress specifically, we used VPD and evaporative fraction (EF). We evaluated the effects from environmental drivers and EF towards GPP products using the structural equation modeling (SEM) in South Korea. We found that GPP products from MODIS algorithm and model simulation results were not restricted from VPD data if VPD was underestimated. We also found that in the cropland area, irrigation effects can relieve VPD effects to GPP. However, GPP products derived from MODIS and CLM 4 had limitation to explain the irrigation effects to GPP. Overall, these results will enhance the understanding of GPP products derived from MODIS and CLM 4.