• 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.

• 한국산업융합학회 논문집
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• 제21권5호
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• pp.227-234
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• 2018

The smart irrigation system using ICT technology is crucial for stable production of upland crops. The objective of this study was to develop a smart irrigation system that can control soil water, depending on irrigation methods, in order to improve crop production. In surface irrigation, three irrigation methods (sprinkler irrigation (SI), surface drip irrigation (SDI), and fountain irrigation (FI)) were installed on a crop field. The soil water contents were measured at 10, 20, 30, and 40 cm depth, and an automatic irrigation system controls a valve to maintain the soil water content at 10 cm to be 30%. In subsurface drip irrigation (SSDI), the drip lines were installed at a depth of 20 cm. Controlled drainage system (CDS) was managed with two ground water level (30 cm and 60 cm). The seasonal irrigation amounts were 96.4 ton/10a (SDI), 119.5 ton/10a (FI), and 113 ton/10a (SI), respectively. Since SDI system supplied water near the root zone of plants, the water was saved by 23.9% and 17.3%, compared with FI and SI, respectively. In SSDI, the mean soil water content was 38.8%, which was 10.8% higher than the value at the control treatment. In CDS, the water contents were greatly affected by the ground water level; the water contents at the surface zone with 30 cm ground water level was 9.4% higher than the values with 60 cm ground water level. In conclusion, this smart irrigation system can reduce production costs of upland crops.

• 한국농공학회논문집
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• 제58권6호
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• pp.1-8
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• 2016

Crop damages due to agricultural drought has been increased in recent years. In Korea, water resources are limited indicating that proper management plans against agricultural drought are required for better water-use efficiency in agriculture. In this study, irrigation intervals and amounts for various crops and soil physical properties (sandy and silt loams) were estimated using the IWMM model. Five different crops (soybean, radish, potato, barley and maize) at the Bangdong-ri site in Chuncheon were selected to test the IWMM model. IWMM assessed agricultural drought conditions using the soil moisture deficit index (SMDI), and irrigation intervals and amounts were determined based on the degree of agricultural drought (SMDI). Additionally, we tested the effects of surface irrigation and sprinkler irrigation methods and various irrigation intervals of 2, 3, 5 and 7 days. In our findings, the irrigation intervals of 5 and 7 days showed the minimum rrigation amounts than others. When we considered that the intervals of 3 or 5 days are usually preferred to fields, the interval of 5 days was determined in our study. The estimated irrigation amounts for different crops were shown as maize > radish > barley > soybean > potato, respectively. The irrigation amounts for maize and barley were highly affected by soil properties, but other crops have less differences. Also, small differences in irrigation amounts were shown between the surface and sprinkler irrigation methods. These might be due to the lack of consideration of water loss (e.g., evapotranspiration, infiltration, etc.) in IWMM indicating model structural uncertainties. Thus, possible water loss (e.g., evapotranspiration, infiltration) need to be considered in application to fields. Overall, IWMM performed well in determining the irrigation intervals and amounts based on the degree of agricultural drought conditions (SMDI). Thus, the IWMM model can be useful for efficient agricultural water resources management in regions at where available water resources are limited.

• 생물환경조절학회지
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• 제15권2호
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• pp.156-161
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• 2006

토마토 초장의 경우 심층수처리는 대조구에 비해 두상관수는 50%, 저면관수는 58% 감소하였고, 표층수 처리구에서는 두상관수는 49%, 저면관수는 56% 감소하였으며, NaCl 처리구에서는 두상관수는 47%, 저면관수는 57%감소하여 저면관수 처리방법이 도장억제에 더 효과적이었다. 지상부 생체중의 경우 두상관수보다 저면관수에서 더 감소하는 경향을 보였으나 뚜렷한 차이가 나타나지 않았다. 지하부 생체중 대조구에 비하여 두상관수는 38%정도 감소한 반면 저면관수는 49% 정도 감소하여, 저면관수에 의해 생육이 현저히 억제되는 결과를 보였다. 지상부와 지하부의 건물중은 생체중과 비슷한 경향을 나타냈다. 이와 같은 결과는 염에 의한 뿌리생육의 저하 때문인 것으로 판단된다. 경경은 대조구에 비해 감소하였지만 처리 방법 간에 뚜렷한 차이를 보이지는 않았다. T/R률에 비추어 보면 두상관수 처리에서 묘소질이 더 뛰어났으나, 묘의 충실도(compactness)는 처리구간 차이는 나타나지 않았다. 토마토의 경우 초장의 억제정도나 묘의 충실도에 비춰보아 저면관수 방법이 도장억제에 더 효과적이라 사료된다. 오이의 경우 처리 농도의 증가에 따라 초장, 생체중, 건물중, 경경, 엽면적이 감소하였다. 저면관수가 두상관수에 비해 도장억제 효과와, 생육억제가 좀 더 뚜렷이 나타나기는 하였으나 두 처리간의 유의적 차이는 나타나지 않았다.

• 한국농공학회지
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• 제30권3호
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• pp.114-120
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• 1988

A water surface profile computation model using a standard step procedure was developed for gradually varied flow at an irrigation channel network. Flow characteristics ab Banweol district near Suweon were field monitored during irrigation periol of 1987. The model was applied to the main system at the district and the simulation results were compared to the field data. The results are sumrnarized as follows ; 1. The simulated water surface profiles from the model were in good agreement with the measured water surface profiles at different flow rates. 2. The model applicability for defining a stage-discharge relationship at a channel reach was demonstrated with reasonable accuracy when water stage and friction factor were given. 3. The roughness coefficient was found to be a major factor sigrificantly affecting computed water surface profile among a few physical input parameters for the model.

• 한국작물학회지
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• 제43권4호
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• pp.264-268
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• 1998

The experiment was conducted to clarify irrigation requirement and percolation rate in rice paddy. The four rice cultural system of no-tin, till, transplanting, and direct seeding condition were treated in the lysimeter filled with sandy loam soil. The amounts of irrigation and soil percolation were measured daily, and irrigation requirement was estimated. The daily percolation was 19.5 l/$\textrm{m}^2$ in no-till direct seeding on flooded paddy surface, 17.4 l/$\textrm{m}^2$ in both of till-direct seeding on flooded surface and no-till transplanting, and 15.2 l/$\textrm{m}^2$ in transplanting plot. This is equivalent to 19.5, 17.4, and 15.2 mm per day, respectively. Highest irrigation requirement was 3,770 l/$\textrm{m}^2$ in no-till direct seeding plots. Others were 3,249, 2,577, and 2,321 l/$\textrm{m}^2$ in till-direct seeding, no-till transplanting and transplanting plot, respectively. The estimated irrigation requirement of no-till transplanting, till-direct seeding and no-till direct seeding was increased by 11, 37, and 59% compared to till-transplanting plot. Percolation rate of no-till transplanting, till direct seeding and no-till direct seeding was increased by 12%, 40%, and 66%, respectively compared to the till-transplanting plot. The percolation rate in paddy soil was increased greatly after reproductive stage of rice.

• 한국토양비료학회지
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• 제46권2호
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• pp.99-104
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• 2013

시설오이 지중관비에서 지중 점적호스를 30 cm에 매설 시에 텐시오미터를 이용한 자동관수센서의 적정 깊이를 제시하고자 2010-2011년까지 2년간에 걸쳐서 조사하였다. 오이의 생육은 텐시오미터 30 cm 깊이에서 낮았으나 텐시오미터 10 및 20 cm에서는 유의성 있는 차이는 없었다. 1년 및 2년차 수량에서도 텐시오미터 30 cm에서 각각 40.9 및 41.2 $Mg\;ha^{-1}$로 가장 적은 생산량을 나타내었나, 텐시오미터 10 cm에서는 57.0 및 56.9 $Mg\;ha^{-1}$, 텐시오미터 20 cm에서는 56.0 및 60.5 $Mg\;ha^{-1}$로 처리간의 차이가 없이 동일한 수량을 나타내었다. 오이재배에서 한 작기 당 질소 및 일일 물 공급량은 63 $kg\;N\;ha^{-1}$의 질소와 1.3 $mm\;day^{-1}$로 물이 공급된 텐시오미터 20 cm 처리에서 질소 및 수분 이용효율이 높았다. 또한 토양깊이 0-30 cm에 대한 뿌리길이에서도 텐시오미터 20 cm에서 0.87 $cm\;cm^{-3}$으로 유의성은 없었지만 가장 높은 값을 나타내었다. 이러한 결과로부터 시설오이에서 지중 점적호스를 30 cm 깊이에 매설 시에 텐시오미터를 활용한 자동관수센서의 적정 깊이는 20 cm인 것으로 판단되었다.

• 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.

• 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.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• 제30권6호
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• pp.455-464
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• 2004

The purpose of this study was to evaluate and compare the influence of Steroid topical irrigation and implant surface on bone healing in the irradiated rabbit tibia. Implant to bone contact surface ratio and the pattern of bone healing around hydroxyapatite(HA) coated implant and pure titanium (Ti) implant which were inserted into the irradiated rabbit tibia were compared. 16 Korean house mature male rabbits were used as experimental animal. Each rabbit received 15 Gy of irradiation. 4 weeks after the irradiation, two holes were prepared in the irradiated tibia of each rabbits, where two surface type of implants were inserted :1) HA coated type and 2) pure Ti type. Right before placing implants, one group of rabbit received steroid irrigation and the other group did saline. After the irrigation, two implants of HA coated type and pure Ti type were inserted into the tibia of each rabbits. Each rabbit were sacrificed at 2nd, 4th, and 8th week after the implantation and the specimens were observed by the light microscope. The pattern of bone healing and histomorphometric analysis of the implant-bone interface were done. The results were as follows. 1. All implants inserted into the irradiated tibia of rabbit did not show any sign of clinical mobility and the bone around implants inserted into the irradiated tibia of rabbit did not show any resorption. 2. The bone to implant contact surface ratio around HA coated implants that received steroid irrigation got more bone to implant contact surface ratio than that of the saline irrigation. This result showed statistically significant(p<0.05). There was no statistically significant difference in 8th week group. 3. Though there was no statistically significant difference HA coated implants had more bone to implant contact surface ratio than pure Ti implant in 2nd and 4th groups, and there was no difference in 8th week group. 4. All implants inserted into the irradiated tibia of rabbit had exhibited successful osseointegraion.