• 한국농공학회논문집
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• 제65권2호
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• pp.73-80
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• 2023

This study was conducted to analyze changes of irrigation water and soil volumetric water content by irrigation method of field soil in Saemangeum reclaimed tideland. The main test irrigation methods was surface drip irrigation, sprinkler irrigation, and sub drip irrigation. In addition, the correlation between irrigation amounts and crop yield by irrigation method was investigated. For soil volumetric water contents increases by 25%, surface drip irrigation took 1.5 hour, sprinkler irrigation took 2.0 hours, and sub drip irrigation took 3.0 hours. As a result of analyzing the irrigation amounts according to the yield, the surface drip irrigation was 2.66 mm/day in the seedling stages, 3.31 mm/day in the vegetative growth stages, and 5.09 mm/day in the flowering stages. Sprinkler irrigation was 2.90 mm/day in the seedling stages, 3.87 mm/day in the vegetative growth stages, and 7.11 mm/day in the flowering stages. Sub drip irrigation was 2.42 mm/day in the seedling stages, 3.09 mm/day in the vegetative growth stages, and 4.87 mm/day in the flowering stages. It was analyzed that there was a statistically significant difference in irrigation amounts by fresh weight and irrigation method (F=4.002, p=0.022), and irrigation amounts by dry weight and irrigation method (F=3.499 p=0.034). Surface drip irrigation was judged to be more appropriate than sprinkler irrigation or sub drip irrigation for field crops in Saemangeum reclaimed land.

• Restorative Dentistry and Endodontics
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• 제18권2호
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• pp.377-386
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• 1993

The purpose of this study was to evaluate the disinfection efficacy of root canal irrigation method and irrigation solution in infected root canals. Access cavity were prepared in single-rooted extracted human teeth and each canals were prepared with step-back method and sterilized with ethylene oxide gas. Prepared teeth were experimentally inoculated in the canals for 30 minutes with four aerobes(Streptococcus mutans, Stapylococcus aures, Streptococcus sanguis, and E. coli) and two anaerobes(Streptoccus intermedius, and Clostrium perfringens). Normal saline, 3% $H_2O_2$, and 3% NaOCl were used as irrgation solutions. And root canals were irrigated with each irrigation solutions manually with disposible syringe or ultrasonic instument. (Apoza Uitrasonc, Taiwan). The irrigation effect on the eradication of S. aures and S. intermedius with normal saline was not similar between manual method and ultrasonic method. No significant differences were observed in the eradication of E. coli and C. perfringens among the irrigation solution and irrespective of the irrigation methods. In S. aurues and S. mutans, there was somewhat different eradication effect according to irrigation solutions, but there was no significant difference between manual method and ultrasonic methods. These results suggest that ultrasonic irrigation method with saline is more effective in some strains than manual irrigation.

• 한국농공학회:학술대회논문집
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• 한국농공학회 2000년도 학술발표회 발표논문집
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• pp.108-113
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• 2000

A field study was performed to investigate the effect of water saving irrigation method on water use efficiency and rice yield. The field plot was 40a (40 ${\times}$ 100m) in size and located at Buryangmyun, Kimjae city, Chonbuk province. Field measurements were made during the growing seasons, May to September of the year 1998 and 1990. Irrigation water volume, drainage water volume, rainfall and ponding depth were measured. Irrigation water management practice employed was such that to keep the ponding depth about 3 to 4cm by intermittent irrigation with drying the soil surface until hair cracks emerge before the next irrigation. The amounts of water volume irrigated and drained were measured by pipe flow meter and ponding depth was observed by using a partly buried 120mm diameter PVC pipe. The results showed that the irrigation water depths, the rainfalls, and the drainage depths were 379mm, 458mm, and 448mm in 1988, and 274mm, 819mm, and 736mm in 1990, respectively. The average yield was 590kg per 10a. The water saving irrigation method saved irrigation water by about 20% with higher yield compared with the traditional method.

• Journal of Biosystems Engineering
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• 제14권2호
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• pp.128-136
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• 1989

The purpose of this study was to develop a computer operated automatic drip irrigation system for application in vinyl-house cultivation. The results can be summarized as follows: 1) The T-type ice compensation wire was used to measure the temperature. The voltage level measured up to 0.02 volt was used as input to an 8-bit A/D converter. 2) A specially devised tensiometer was used to content the watering system. When the needle of the pressure gauge reaches the lower threshold position it turns on the pumping system and turns off when it reaches higher threshold position. 3) In order to use the multiple gypsum blocks for one transducer, reed relays and a D/O board were used to make the sequential switching possible. 4) It was possible to automate the trickle irrigation system for the whole growth period of vinyl-house crops with the help of microcomputer. 5) In terms of furrow irrigation, the irrigation water consumption was the smallest, 2.8 times less than conventional method of surface trickle irrigation, 3.4 times less than subsurface trickle irrigation method. 6) In terms of productivity of cucumber, there was a drop in productivity when compared to furrow irrigation method, 7.2% for surface trickle irrigation, 27.4% for subsurface irrigation method.

• Journal of Biosystems Engineering
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• 제30권2호
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• pp.102-109
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• 2005

Water consumption at the farm is up to 48 percent of water resource of South Korea while manufacturing industry's is only $9.6\%$. The area of arable land is 2,077,067 ha and 27 percent of it is used for growing fruits and vegetables using furrow or surface irrigation at the greenhouse. Surface irrigation at the greenhouse for fruits and vegetables has problems such as over watering and insufficient supply of water to the fine roots of the plant. However, the research on the new method of irrigation to save water usage is few. The characteristics of soil wetting was measured for using surface irrigation and underground trickle irrigation method where water was supplied at 10, 15, 20, and 25 cm beneath the surface ground. Followings are summary of this study. 1. The efficiency of underground trickle irrigation was expected to be as high as twice of surface irrigation such as drip watering or sprinkling. 2. This improvement could be possible by using less than $50\%$ of irrigation water than surface irrigation to supply similar amount of water near fine roots. 3. Surface irrigation causes soil compaction as deep as 20 cm below the surface ground which reduces soil porosity and root respiration ending up developing less fine roots. 4. Underground trickle irrigation can prevent overdamping in the greenhouse since it does not over wet the surface soil. At winter, the amount of agricultural chemical usage could be reduced since this irrigation method does not develop blight or crop disease from condensation of water vapor.

• 한국농공학회지
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• 제35권4호
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• pp.31-38
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• 1993

For efficient irrigation of structured horiculture and upland crops, a new technique of drip irrigation using the turbo-tape for Autumn Chinese cabbage was developed. The turbo-tape worked well, and based on this study The following results were obtained ; 1. The emission uniformity of the turbo-tape was very good with a uniformity coefficient of 92.5%. 2. Starting point of irrigation at 80% of the wilting point was better than at the wilting point itself. 3. The irrigation amounts for the Autumn Chinese cabbage cultured ranged 315 to 470mm depending upon the irrigation methods, turbo-tape irrigation method could conserve irrigation water about 37% compared to the furrow irrigation method. 4. Average yields were 2, 430g when the starting point of irrigation was at the wilting point, while 2, 680g when it was at 80% of the wilting point.

• 한국농공학회지
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• 제45권6호
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• pp.96-108
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• 2003

Agricultural water occupies the largest portion of total water use in Korea, and generally researches on the development of agricultural water have been stressed on the demand of agricultural water itself. But it is unavoidable to change a policy from the development of water resources to cope with the increase of water demand to the effective management of existing water resources. Evaluation of the decrepitude of irrigation facilities and their reasonable maintenance are important for the effective supply and use of agricultural water. Therefore it is necessary to develop evaluation technique that diagnoses the current condition of irrigation canals and suggest a countermeasure to improve the found problems. 25 items in 6 classes were selected for the evaluation of irrigation canal systems, and the weighted value between the items was calculated using AHP (Analysis Hierarchy Process) method. The current condition of the irrigation facilities was evaluated from the class evaluation marks, and ranking was decided from the total marks between the projects, and finally the priority of the project for the improvement was given.

• International Journal of Advanced Culture Technology
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• 제6권3호
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• pp.178-186
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• 2018

Generally, in terms of the development of irrigation scheme, the efficient water resource management that supplies the irrigation water in consideration of the required time and accurate quantity to grow the crop should be conducted. The water resource assessment should precede to supply the irrigation water efficiently. The water resources assessment is divided into the water requirement analysis and the water availability assessment. In case of Korea, the major crop is paddy rice unlike crops of Africa, such as sugarcane, maize, and cassava, etc. Because it is not familiar with the method for upland irrigation development in tropical area, it needs to know the water resources assessment for irrigation scheme development about these crops. The Natama Scheme in Chiradzulu District of the Southern Malawi was selected as study area, which has tropical climate. From the collected meteorological data, the evapotranspiration was analyzed by Penman-Monteith Method and the effective rainfall was analyzed by USDA Soil Conservation Service Method. This study displays the results that for study area, the evapotranspiration varies from 2.80 mm/day to 5.51 mm/day and the effective rainfall varied from 2.1mm to 149.0mm. According to the selected crop (Green Maize, Dry Maize), the unit water requirement (UWR) and water demand (WD) considering the irrigation efficiency, irrigation time and irrigation area were estimated to be $0.00122m^3/s/ha$ and $0.0122m^3/s$ respectively. For the water availability assessment, the runoff of Natama scheme was calculated by specific yield method. The water availability was evaluated through reviewed differences of discharge between $Q80_{intake}$ and Total WD, and the irrigation water can be supplied sufficiently in the existing 10ha of Natama scheme. As a result of reviewing the extensibility of irrigable area, total WD of scheme is $0.02313m^3/s$, and $Q80_{intake}$ is $0.02387m^3/s$ ($Q80_{intake}$ > Total WD). Therefore, Natama scheme can be extended from 10 ha to 17 ha in the dry season in consideration of the $Q80_{intake}$.

• 한국농공학회지
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• 제42권
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• pp.9-16
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• 2000

GPS(Global Positioning System) surveying is an effective method using satellite measurement system and can be applied to construction of digital map of irrigation canal networks. In this study, GPS surveying method for irrigation structures was developed. A selected main canal of an irrigation district were surveyed by GPS. The obtained surveying results were corrected by post-processed DGPS (Differential Global Positioning System) and imported to GIS for the digital map construction.

• 한국농공학회논문집
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• 제48권3호
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• pp.11-20
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• 2006

In this study, the actual water management were investigated and analyzed on site for effective use of the paddy irrigation water. And this study is tried to analyze the difference between simulated irrigation water according to current design method and actual water supply in experimental reservoirs. The reservoirs in Idong, Yongdeok and Misan, which are managed by Korea Rural Community & Agriculture Corporation, were selected fur field investigation. The purpose of this study is to suggest an improved method for irrigation water calculation through quantitative and periodical analysis considering the difference between design and actual field condition.