• 대한토목학회논문집
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• 제29권2B호
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• pp.173-179
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• 2009

수자원사업에 의해 공급되는 공업용수는 대상 사업체에서 노동, 자본, 토지 등과 더불어 필수적인 투입재이다. 이러한 투입재의 안정적인 확보는 해당 산업이 부가가치를 창출하는데 매우 중요한 사안이다. 공업용수의 공급이 중단될 시 해당 산업에서의 피해액은 동일한 공급량 기준으로 봤을 때, 생활용수나 농업용수에 비해 매우 크다고 알려져 있다. 이처럼 공업용수의 실제 가치는 직관적으로 매우 높게 인식하고 있으나, 경제성분석을 위한 공업용수의 편익산정에 대한 구체적인 연구는 많지 않았다. 본 연구는 수자원사업으로부터 공급되는 공업용수의 가치를 확인하고, 경제성분석시 공업용수공급편익 추정을 위한 수단으로서 한계생산가치를 산정하였다. Cobb-Douglas 생산함수와 Translog 생산함수를 이용하여 실증분석한 결과, 전국 평균 한계생산가치는 각각 5,427원/$m^3$, 5,583원/$m^3$로 산정되었고, 산업분류별로 11가지 산업에 대한 한계생산가치를 산정하였다. 본 연구에서 제시한 산업별 한계생산가치는 앞으로 공업용수편익을 산정하는데 중요한 자료로 사용될 수 있으리라 판단된다. 또한, 위급상황시 용수배분에 대한 의사결정이나 수자원사업시 비용배분 등의 문제에서 본 연구의 결과는 합리적인 기준을 제공할 수 있으리라 기대된다.

• 한국작물학회지
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• 제49권5호
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• pp.363-367
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• 2004

The deep irrigation of rice plants brings about some beneficial effects such as reduced tiller production which results in the formation of bigger panicles, prevention of chilling injury, reduced weed growth, etc. The present study was carried out to examine the involvement of ethylene in the suppression of tiller production due to deep water irrigation in rice (cv. Dongjinbyeo). The ethylene production was induced in leaf sheath within 24 hours after the deep water irrigation and has increased even until 30 days after the treatment, recording 4.5-fold increase as compared to the shallow-irrigated rice plants. In the deep water irrigated rice plants, ethylene was accumulated to a high concentration in the air space of submerged leaf sheath as the irrigated water deterred the diffusion of ethylene out of the leaf sheath and ethylene biosynthesis was accelerated by the deep irrigation as well. The ethylene concentration recorded 35-fold increase in the deep-irrigated rice plants for 35 days. The tiller production was reduced significantly by the deep irrigation with water, the tiller bud, especially tertiary tiller bud differentiation being suppressed by the deepwater irrigation treatment, whereas the rice plants deep-irrigated with solutions containing $10^{-5}$ M or $10^{-6}$ M silver thiosulfate (STS), an action inhibitor of ethylene, showed the same or even higher production of tillers than those irrigated shallowly with water. This implies that the ethylene is closely linked with the suppression of tiller production due to deep water irrigation. In conclusion, ethylene, which was induced by hypoxic stress and accumulated in the leaf sheath due to submergence, played a key role in suppressing the tiller production of the deepwater irrigated rice.

• Ocean Science Journal
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• 제43권1호
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• pp.39-48
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• 2008

Tritium ($^3H$ or T) has been produced mostly by atmospheric nuclear weapon tests, and entered the ocean in the form of water (HTO). As tritium exists as water itself, it has been regarded as an ideal tool to study the transport of water masses. In April 2001 we collected water samples in the western Japan Basin (WJB) for tritium and helium measurement. The timely sampling provided direct evidence of the bottom water formation, resulting in the drastic increase in tritium concentration from 0.3 TU in 2000 to 0.67 TU in 2001. Considering that the new bottom waters were found mostly in the WJB, it implies that maximum 1% of the whole bottom layer below 2600 m should be replaced with the surface water during the severely cold winter 2000 2001. $^3H-^3He$ age, showing the elapsed time since the water left from the surface, can be used to calculate oxygen utilization rate by dividing AOU by the age. Under the condition of 90% oxygen saturation in the surface water, the integration of OUR in the water column below 200 m yields net oxygen consumption of 12 mol $(O_2)m^{-2}yr^{-1}$, which corresponds to the export production of $99\;g\;C\;m^{-2}yr^{-1}$. This estimate is comparable to a previous estimate based on satellite data and implies that the ratio of export to primary production(f-ratio) is as high as 0.5 in the WJB.

• Ocean and Polar Research
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• 제36권2호
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• pp.157-163
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• 2014

This study analysed the economic feasibility per hectare of grow out phase production of Oyster farming by rising water temperature in Ocean. Elevated Water temperature by climate change had a bad influence for oyster production and economic feasibility. In the case of production units, the total output of oyster decreases from 213,840 to 205,594 units. Using cost-benefit analysis with discounting rates (5.5%), we estimated the net present value (NPV) and benefit cost ratio (BCR) until 2100 years. The model results showed that the NPV without water temperature rise was 1,565,619,893 won and the NPV with water temperature rise was 1,540,493,059 won. Also, BCR estimated that the former was 2.095 better than the latter was 2.077. To summarise, the economic effect per hectare of water temperature rise in ocean did the damage to the economic loss about 25,126,834 won.

• 한국수산과학회지
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• 제20권5호
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• pp.381-390
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• 1987

본 연구는 1985년 5월부터 1986년 5월까지 삼천포 화력발전소를 대상으로 발전소 냉각계통의 가동이 식물플랑크톤의 기초생산력에 미치는 영향을 구명하기 위하여 실시되었다. 발전소 냉각계통이 총기초생산력에 미치는 영향은 평균 $7.5\~58.9\%(4.6\~12.1mgC/m^3/h)$이었으며, 순기초생산력의 경우는 이보다 높은 수준이 $58.7\~83.5\%(8.4\~11.9mgC/m^3/h)$. 영향요인 중 가장 큰 요소는 냉각계통 통과시 입는 기계적인 영향으로 그 범위가 $21.1\~110.7\%$에 달하였다. 삼천포 화력발전소 냉각계통에 이한 식물성탄소에 해당하는 량으로 추계되었다.

• 한국수소및신에너지학회논문집
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• 제14권3호
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• pp.187-194
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• 2003

The production of hydrogen fuel depends basically on the water electrolysis. The study on the decrease of overpotential which activates the hydrogen production is the core to elevate the hydrogen production efficiency on principle. Characteristics on the overpotential decrease are observed through the micro reaction by ultrasonic in electrolytic cell. For the above, the electrochemical analyzer, i.e., BAS is applied, Experiments with ultrasonic forcing into 4 kinds of solution such as city water, city water plus nitrogen. distilled water, and distilled water plus nitrogen are carried out. And concentrations of KOH are 0%, 10%, 20% and 30%. The basic characteristics of the overpotential decrease are obtained through the analysis by LSV technique in sweep technique. In results, it is clarified that the ultrasonic influences the decrease of overpotential to obtain the efficiency elevation of hydrogen fuel production.

• 농업과학연구
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• 제43권4호
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• pp.547-559
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• 2016

The objectives of this study were to investigate the effects of excessive soil-water on crop growth and to predict decrease of yields caused by excessive soil-water. The following five crops were selected for investigation: foxtail millet, proso millet, sorghum, adzuki bean, and sesame. These were planted in pots and a soil-water table was set to 10cm for 10 days. Crop susceptibility (CS) factors and stress-day indexes (SDI) were calculated for each crop to estimate effects of excessive soil-water. SDI models were calculated using CS and SDI data for each crop and predicted the yields of crops cultivated in paddy fields. All crops were cultivated in paddy fields with different soil water contents to evaluate the yield-SDI models. Results showed that yields decreased most when crops were affected by excessive soil-water at the early development stage. Decrease of yields was the greatest when the excessive soil-water treatment was applied at early growth stage. In the field experiment, crops from soils with the greatest soil-water content had the smallest yield, while ones from soils with the smallest soil water contents showed the greatest yields. Observed yields from the field and predicted yields from SDI models showed the least correlation for proso millet, foxtail millet, and adzuki bean and the greatest correlation for sesame. In conclusion, proso millet, foxtail millet, and adzuki bean were more susceptible to soil water than other crops, while sorghum and sesame were more suitable to cultivation in paddy fields.

• 한국농공학회논문집
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• 제63권5호
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• pp.95-105
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• 2021

Drought is a disaster that causes prolonged and wide scale damage. Recently, the severity and frequency of drought occurrences, and drought damage have been increased significantly due to climate change. As a result, a quantitative study of drought factors is needed to better understand and prevent future droughts. In the case of agricultural drought, several existing studies examine the economic damage caused by droughts and their causes, but these studies are not well suited to estimating crop-oriented agricultural drought damage and the factors that absolutely affect agricultural drought. This study determines which factors most affect agricultural drought. It examines meteorological factors and those related to agricultural water supplied by irrigation facilities. Rice paddy production per unit area is lower than the average from the last two years where agricultural drought occurred. We compare the relative frequency of agricultural drought impacts with irrigation facilities, effective reservoir storage, the number of water supply facilities, and the meteorological drought index such as Standardized Precipitation Index (SPI). To identify factors that affect agricultural drought, we correlate rice paddy production anomalies with irrigation water supply for the past two years. There was a high positive correlation between rice paddy production and irrigation water usage, and there was a low or moderate negative correlation between rice paddy production anomalies compared to the average of the past two years and SPI. As a result, agricultural water supply by irrigation facilities was judged to be more influential than meteorological factors in rice paddy production. This study is expected to help local governments establish policies related to agricultural drought response.

• 농업과학연구
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• 제45권4호
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• pp.749-760
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• 2018

In Korea, the largest agricultural lands are paddy fields which have poor infiltration and drainage properties. Recently, the Korean government has pursued cultivating upland crops in paddy fields to reduce overproduced rice in Korea. For this policy to succeed, it is critical to understand the topographic information of paddy fields and its effects on upland crops cultivated in the soils of paddy fields. The objective of this study was to characterize the growth properties of sesame and perilla from paddy fields with three soil topographic features and soil water effects which were induced by the topographic features of the sesame and perilla. The crops were planted in paddy fields located in Miryang, Gyeongnam with different topographies: mountain foot slope, local valley and alluvial plain. Soil water contents and groundwater levels were measured every hour during the growing season. The paddy field of the mountain foot slope was significantly effective in alleviating wet injury for the sesame and perilla in the paddy fields. The paddy field of the mountain foot slope had a decreased average soil water content and groundwater level during cultivation. Stress day index (SDI) from the alluvial plain paddy field had the greatest values from both crops and the smallest from the ones from the paddy field of the mountain foot slope. This result means that sesame and perilla had the smallest stress from the soil water content of the paddy field on the mountain foot slope and the greatest stress from the soil water content of the alluvial plain. It is important to consider the topography of paddy fields to reduce wet injury and to increase crop yields.

• Asian-Australasian Journal of Animal Sciences
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• 제33권7호
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• pp.1180-1190
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• 2020

Objective: To develop healthier comminuted meat products to meet consumer demand, the gel properties, rheological properties, microstructure and water distribution of pork meat batters formulated with various amounts of bamboo shoot dietary fiber (BSDF) were investigated. Methods: Different levels of BSDF (0% to 4%) were added to pork batters, and the pH, color, water-holding capacity, texture and rheological properties of pork batters were determined. Then, pork batters were analyzed for their microstructure and water distribution using scanning electron microscopy (SEM) and low-field nuclear magnetic resonance (LF-NMR). Results: Compared with the control, BSDF addition into meat batters showed a significant reduction in L^*-value and a significant increase in b^*-value (p<0.05). BSDF addition of up to 4% reduced the pH value of pork batters by approximately 0.15 units; however, the cooking loss and expressible water loss decreased significantly (p<0.05) with the increased addition of BSDF. The hardness and gel strength were noticeably enhanced (p<0.05) as the content of BSDF increased. The rheological results showed that BSDF added into pork batters produced higher storage modulus (G') and loss modulus (G") values. The SEM images suggested that the addition of BSDF could promote pork batters to form a more uniform and compact microstructure. The proportion of immobilized water increased significantly (p<0.05), while the population of free water was decreased (p<0.05), indicating that BSDF improved the water-holding capability of pork batters by decreasing the fraction of free water. Conclusion: BSDF could improve the gel properties, rheological properties and water distribution of pork meat batters and decrease the proportion of free water, suggesting that BSDF has great potential as an effective binder in comminuted meat products.