• 한국농공학회논문집
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• 제57권1호
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• pp.69-78
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• 2015

The objective of this study was to investigate characteristics of irrigation return flow from paddy block in a reservoir irrigated district during growing seasons. The irrigation return flow was divided into three parts, quick return flow from irrigation canal (RFI), quick return flow from drainage canal (RFD), and delayed return flow (DRF). The RFI was calculated from water level and stage-discharge relationships at the ends of the irrigation canals. The DRF was estimated using measured infiltration amount from paddy fields of the irrigated district. A combined monitoring and modeling method was used to estimate the RFD by subtracting surface runoff from surface drainage. The paddy block irrigated from the Idong reservoir was selected to study the irrigation return flow components. The results showed that daily agricultural water supply (AWS), the RFI, and the RFD were $27.4mm\;day^{-1}$, $4.9mm\;day^{-1}$, and $19.8mm\;day^{-1}$, respectively in May, which were greater than other months (p<0.05). The return flow ratio of the RFI and the RFD were the greatest in July (34.6%) and May (72.3%), respectively. The daily AWS was closely correlated with the RFD (correlation coefficients of 0.76~0.86) in except for July with, while correlation coefficient with the RFI were 0.56 and 0.42 in June and July, respectively (p<0.01). The total irrigation return flow was 1,965 mm in 2011, and 1,588 mm in 2012, resulting in total return flow ratio of 84.6% and 79.1%, respectively. This results indicate that substantial amounts of agricultural water were returned to streams as irrigation return flow. Thus, irrigation return flow should be fully considered into the agricultural water resources planning in Korea.

• 한국농공학회논문집
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• 제61권2호
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• pp.97-104
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• 2019

The purpose of this study was to establish the estimation method of irrigation water amount for sewage treated water reuse for agricultural purpose. To calculate the irrigation water amount, we adopted Penman-Monteith for potential evapotranspiration estimation and applied crop coefficient and irrigation efficiency factor. We developed the irrigation water amount calculation program using C language in Xcode environment. The target district for calculation is having 259 ha of agricultural land located near the Jinyeong Clear Water Circulation Center in Hanrim-myeon, Gimhae city. The meteorological data of the study area were obtained from Changwon weather station from 1986 to 2017. Calculated average and maximum of annual mean potential evapotranspiration were 2.72 mm/day and 6.22 mm/day, respectively. We used K-S (Kolmogorov-Smirnov) for goodness-of-fit test to find optimal probability distribution of annual mean and maximum evapotranspiration. As a result, the normal distribution was selected for the appropriate distribution. The annual mean and maximum potential evapotranspiration for 10-year return period by applying normal distribution were 2.88 mm/day and 6.76 mm/day, respectively. Assuming that the irrigation efficiency is 80%, the irrigation water requirement was calculated as $36.05m^3/day/ha$ and $84.45m^3/day/ha$, respectively, when annual mean and maximum potential evapotranspiration were applied. The actual irrigation water amount can be calculated by applying the crop coefficient and cropping days for the study area based on the developed irrigation water amount estimation program in this study.

• 한국산업융합학회 논문집
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• 제24권3호
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• pp.333-341
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• 2021

Irrigation scheduling is a water management strategy of applying the proper amount of water in a plant's root zone at the right time to maximize profit. We conducted an experimental evaluation of the response of soybean, sorghum, and sesame to an irrigation scheduling scheme. The soil water contents were adjusted in the root zone between 20% and 28% to reflect changes in crop water consumption. The other ones fixed at 25% during the whole growing season were compared to evaluate the effectiveness of irrigation scheduling. Surface drip irrigation (SDI) were employed as an irrigation method. For all three crops, the evapotranspiration (ET) was the greatest at flowering stage (6.93 mm), followed by vegetative growth stage (5.00 mm) and maturity stage (2.53 mm). The irrigation amount was significantly reduced by 21.8% (soybean), 22.2% (sorghum), and 16.1% (sesame), respectively, compared with the ones at constant soil water content treatment. Their water use efficiency (WUE) were also much higher than the controls: 2.65-fold increase at soybean, 1.82-fold increase at sorghum, and 1.47-fold increase at sesame. These results showed that an effective irrigation scheduling on upland crops (soybean, sorghum, sesame) could increase crop yield while minimizing water use.

• Journal of Chest Surgery
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• 제36권6호
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• pp.431-435
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• 2003

개심술 후 발생하는 심부 흉골 창상감염(급성 종격동염)은 아주 심각한 합병증으로 높은 이환율, 사망률, 그리고 입원기간의 연장을 보인다 치료 결과는 주로 흉골 창상감염의 조기 진단과 적절한 외과적 조치에 의존한다. 개심술 후 심부 흉골 창상감염을 보였던 4예에서 광범위한 변연절제술, 항생제 용액의 높은 압력 하 세척, Robicsek방식에 의한 흉골의 재 고정, 항생제 용액을 사용한 세척-흡입법을 통해 성공적인 치료를 하였기에 문헌 고찰과 함께 보고한다.

• 한국농공학회논문집
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• 제54권6호
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• pp.39-44
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• 2012

Water supply capacity and operational capability in agricultural reservoirs are expressed differently in the limited storage due to seasonal and local variation of precipitation. Since agricultural water supply and demand basically assumes the uncertainty of hydrological phenomena, it is necessary to improve probabilistic approach for potential risk assessment of water supply capacity in reservoir for enhanced operational storage management. Here, it was introduced the irrigation vulnerability characteristic curves to represent the water supply capacity corresponding to probability distribution of the water demand from the paddy field and water supply in agricultural reservoir. Irrigation vulnerability probability was formulated using reliability analysis method based on water supply and demand probability distribution. The lower duration of irrigation vulnerability probability defined as the time period requiring intensive water management, and it will be considered to assessment tools as a risk mitigated water supply planning in decision making with a limited reservoir storage.

• 한국농공학회지
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• 제40권2호
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• pp.81-91
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• 1998

Water level of irrigation reservoir during the flood season could be kept to a certain level, so called, flood control level by releasing the flood inflow in advance in order to reduce the peak discharge of next coming flood and the damage of inundation. Concept of restriction intensity of water supply was introduced to evaluate the influence of flood control volume on the irrigation water supply. Restriction intensity can be calculated by multiplying the ratio of restriction to the days of restriction which are obtained from the operation rule curve and daily water level of irrigation reservoir and it has the dimension of % day. The method of restriction intensity was applied to the Yedang irrigation reservoir with the observed data of 30 years to review whether the present flood control volume is reasonable or not, and suggest the optimal flood control volume, if possible.

• 한국농공학회논문집
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• 제58권2호
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• pp.11-20
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• 2016

Korea has 17,500 irrigation dams and facing variety of causes that jeopardize dam safety. With limited resources available to manage large inventory, a portfolio risk analysis application method for numerous irrigation dam safety is essential. The purpose of this study is to find an optimum way to adopt the risk analysis to the large number of irrigation dams in Korea and to propose the portfolio risk analysis process for irrigation dams. In this study, the necessity of the risk analysis for reservoirs safety has been suggested and a phased process using pre-screening and screening methodology has been proposed. This proposed procedure will help to effectively introduce the risk analysis for reservoirs safety in Korea.

• 한국농공학회지
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• 제17권3호
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• pp.3795-3814
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• 1975

The purpoes of this thesis is to study the effect of the variation of the beginning date of the suspension of irrigation and the length of intermittent suspension period of irrigation in the paddy field on the growth and yield of rice, so as the provide a critical limit of saving irrigation water and an irrigation method to prevent drough damage in rice cultivation. In this experiment, the rice variety adopted was NONGRIM No.29. There were seven main test plot, each test plot having a different beginning date of the suspension of irrigation. A main test plot was susdivided into five small test plots, each having a different length of the suspension period of irrigation. The results obtained in this experiment are summarized as follows: 1. The number of tillers is controlled by the treatment of the suspension of irrigation, its beginning date being early of late. The reductive effects of beginning dates of suspension upon the number of tillers. investigated on July 30, are about 84% for the treatment suspended on July 8, 87% on July 12, and 92% on July 19, respectively, in comparison with the standard plot. However. the suspenion treatments after the foregoing dates does not affect the control of their numbers. On the other hand, the lengths of intermittent suspension periods influence highly on the number of tillers to be restrained considerably, the decrease ratio ranging from 91% to 80% Both treatments on dates and periods are so intermingled that the restraining effects of suspension periods become greater as the dates of its beginning are earlier. 2. The elongation of plant hieghts also restrained considerably by the longer periods and earlier dates of suspension treatments of irrigation. Especially, the effects of the lengths of suspension periods become more serious. 3. Heading dates are delayed by two to five days through the suspension treatments of irrigation. However, the heading stage ends almost on the same day without relation to the differences between the irrigation suspension treatments. In the test plot where the suspension date of irrigation comes after the young panicle forming stage, the heading stage ends one or two days later than in the standard test plot. 4. Both culm lengths and panicle lengths show significant differences in their values, i.e., their lengths are shorter, as the begining dates of irrigation suspension are earlier and the suspension periods are longer. 5. The earlier the beginning date and the longer the period of irrigation suspension, the less is the number of panicles per hill in comparison with the standard plot. 6. The earlier the beginning date and the longer the period of irrigation suspension, the higher is the significant difference in the number of kernels per panicle in comparison with that in the standard test plot, i.e., the less is the number of kernels per panicle. 7. The earlier the beginning date and the longer the period of irrigation suspension, the lighter are the weights of rough rice and straws per hill in comparison with those in the standard plot.

• Restorative Dentistry and Endodontics
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• 제34권5호
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• pp.390-396
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• 2009

이 실험의 목적은 $EndoVac^{(R)}$과 $EndoActivator^{(R)}$를 이용한 근관세척시 근관 내 접종된 Enterococcus faecalis의 제거 효율을 기존의 irrigation needle을 이용한 방법과 비교 평가하고자 함이다. 발거된 70개의 단근치를 사용하였으며 .04 taper ProFile #40까지 근관형성 후 치아를 멸균하고 근관에 E. faecalis를 접종하고 배양하였다. 치아는 근관세척 방법에 따라 20개씩 3개의 실험군과 2개의 대조군으로 나누었다. 2.5% 치아염소산나트륨을 사용하여 근관세척 시행 후 일차 표본을 채취하였고, 다시 근관 내에 배양액을 채우고 24시간 동안 배양 후 이차 표본을 채취하였다. 표본은 colony forming units (CFU) 값을 얻기 위해 BHI agar plate에 배양하였다. 일차 표본 결과에서는 모든 실험치아 중 기존의 근관세척 방법을 이용한 하나의 근관에서 양성 배양을 보였다. 이차 표본 결과에서는 $EndoVac^{(R)}$ 실험군에서 가장 적은 양성 배양을 보였으며, 기존의 근관세척 방법과 비교시 통계적으로 유의한 차이를 보였다. 실험 결과에 따르면 $EndoVac^{(R)}$은 근관 내 접종된 E. faecalis의 제거에 있어 기존의 근관세척 방법보다 더 좋은 효율을 보였다.

• 생물환경조절학회지
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• 제19권1호
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• pp.19-24
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• 2010

토마토 펄라이트 자루재배에서 기존에 알려진 배액 전극제어법 적용시기를 가능한 앞당기고, 배양액을 절감하기 위해 수행되었다. 실험처리는 정식후 15일차(T-15), 19일차(T-19), 22일차(T-22)에 배액전극제어법을 적용하는 3개 처리와 타이머법 1개 처리를 실시하였다. 기존의 정식후 1개월 이후에 배액전극제어법 적용하는 관행보다 2주 앞당긴 15일차 처리부터 작물이 배액전극제어법에 반응하는 것으로 나타났다. 생장 및 수확량은 배액전극법에서 높았다. 용수이용효율과 비료이용효율은 T-15 처리에서 가장 경제적이었고, 타이머법 처리는 경제성이 낮았다. 따라서 배액전극제어법 처리시기를 빨리 적용할수록 경제성이 높음을 알 수 있었다.