• Magazine of the Korean Society of Agricultural Engineers
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• v.43 no.2
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• pp.94-104
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• 2001

A pilot study was performed at the experimental field of Konkuk University in Seoul, to examine the feasibility of the constructed wetland system for sewage and the effect of treated sewage irrigation on the paddy rice culture and its soil characteristics. The constructed wetland performed well, in that effluent concentrations of pollutants were significantly lower than concentrations of the influent. Median removal efficiencies of BOD$_{5}$ was about 78% and slightly lower during winter. Removal efficiencies form TN and TP were approximately 48 and 21%, respectively, and relatively less effective than that of BOD$_{5}$. Irrigation of treated sewage to paddy rice culture did not affect adversely in both growth and yield of rice. Instead, plots of treated sewage irrigation showed up to 50% more yield in average than the control plot. It implies that treated sewage irrigation might be beneficial to rice culture rather than detrimental as long as it is treated adequately and used properly. Soil was sampled and analyzed before transplanting and after harvesting. pH was slightly increased due to irrigation water, but it may not be concerned as long as the treated sewage is within the normal range. EC was increased in first year but decreased in second year, therefore salts accumulation in the soil could be less concerned. OM and CES was slightly increased, which might be beneficial on growing plants. TN did not show apparent pattern. Available phosphorus was decreased after rice culture, but the quantity of phosphorus(TP-available phosphorus) was rather increased which implies that excessive phosphorus supply may result in phosphorus accumulation in the soil. Overall, the constructed wetland was thought to be an effective sewage treatment alternative, and treated sewage could be reused as a supplemental source of irrigation water for paddy rice culture without causing adverse effect as long as it is treated adequately and used properly. For full-scale application, further investigation should be followed on environmental risk assessment, tolerable water quality, and fraction of supplemental irrigation.ion.

• Journal of The Korean Society of Agricultural Engineers
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• v.50 no.5
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• pp.3-15
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• 2008

This study aims to simulate the 3 dimensional (3D) model of Keum-man connection canal using geographic information system (GIS) as well as considering design in viewpoint of engineering. The canal connects from Keumkang to Mangyungkang in order to supply fresh water into Saemankeum lake. This study used 3 dimensional spatial planning model (3DSPLAM) process to generate the 3D model, which has not only several planning layers in actual process, but also their corresponding layers in modeling process to simulate 3D space of rural villages. The discharge of the canal is $20m^3/s$ on slope of 1/28,400 in the canal length of 14.2km, which consists of pipe line and open channel. This study surveyed the route of the canal and its surrounding environment for facilities to make images in the 3D graphic model. Besides, the present study developed data set in GIS for geogrphical surface modeling as well as parameters in hydraulic analysis for water surface profile on the canal using HEC-RAS model. From the data set constructed, this study performed analysis of water surface profile with HEC-RAS, generation of digital elevation model (DEM) and 3D objects, design of the canal section and route on DEM in AutoCAD, and 3D canal model and its surrounding 3D space in 3DMAX with virtual reality. The study result showed that the process making 3D canal model tried in this study is very useful to generate computer graphic model with the designed canal on the surface of DEM. The generated 3D canal can be used to assist decision support for the canal policy.

• Proceedings of the Korea Water Resources Association Conference
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• 2007.05a
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• pp.662-666
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• 2007

하수처리수를 농업용 목적으로 재이용하기 위한 기술을 실제 현장에 보급하기 위해 하수처리수가 주 수원공인 양수장에 하수처리수 재처리시스템인 $\ulcorner$농업용수 재이용공급시스템$\lrcorner$을 설치하였다. 본 양수장은 1992년 준공되었으며 양수장 유입구 상류 200m지점에 하수종말처리장 방류구가 위치해 있어 직접적으로 하수처리수가 양수장에 유입되어 농경지에 관개수를 공급하고 있었다. 본 시스템을 설치하기 위해 연간 사용량을 조사하여 적정 처리유량 및 운전시간을 설계하였고 유입수 수질분석을 바탕으로 하수재이용 공급시스템을 설치하여 관개목적에 적합한 수질로 공급할 수 있도록 하였다. 또한 수질 모니터링 시스템을 설치하여 공급 기간 동안 수질변동 상황에 대해 신속한 대처가 가능하도록 시스템을 구성하였다. 현재 농촌지역은 주변상황으로 인해 하수처리수를 관개용수로 이용할 수밖에 없는 지역이 발생하고 있고 앞으로도 하수처리장이 계속 증설되고 있는 한 기존의 농업수리시설물은 하수처리수의 영향이 더욱 커질 것으로 판단되므로 이러한 깨끗한 용수가 위협을 받고 있는 지역에 대해서는 안전한 농산물 생산 도모가 가능한 $\ulcorner$농업용수 재이용 공급시스템$\lrcorner$의 도입이 고려되어야 할 것이다.

• Journal of agricultural medicine and community health
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• v.9 no.1
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• pp.56-66
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• 1984

Giardia lamblia is a pathogenic flagellate causing intestinal disorders such as diarrhea, abdominal pain and malabsorption of nutrients. Giardia is mainly infected by the ingestion of contaminated foods per os. Craun (1979) has recently reported that mass infection of this flagellate through the contaminated water supply systems is one of public health hazards. Also, so-called traveller's diarrhea is sometimes caused by Giardia infection (CDC, U.S.A., 1971). However, a few epidemiological studies figuring out the mode of infection or control measures of Giardia infection has been done so far in Korea. The present study was aimed to know the prevalence of Giardia infection in several Korean populations, detectability of this flagellate in water systems and the viability of the cysts against sewages and disinfectants applying to drinking water. In the present study, 388 stool specimens from orphanage children in Chun-joo, Chung-joo, On-yang and Chun-an areas and 538 stool specimens from inhabitants in Woo-do, In-chon, and Chun-joo were examined by formalin-ether concentration technique to detect out Giardia cysts. On the other hand, water samples from 14 sites of Han River and its tributaries were collected in May through July, 1984. Fifty liter of water sample in each sampling site was then filtered through water filtering system deviced by U.S. Environmental Proutection Agency and the sediments rinsed out from the thread rolls, a part of water filtering system, were examined to detect out the Giardia cysts. In order to observe the viability of Giardia cysts in the sewage samples, the cysts were treated in it at $4^{\circ}C$ or $25^{\circ}C$ for 7 through 28 days. For this purpose, the cysts were also exposed to various concentrations of disinfectants such as chlorine, iodine and ozone gas for proper time intervals. After treatment, the viability test of the Giardia cysts were carried out by method of Rice and Schaefer (1981) with minor modification. The results obtained in this study were as follows : 1) The detection rates of G lamblia cysts in the stool specimens were 18.3% in orphans and 4.3% in general examinees. 2) The prevalences of Giardia Infection were higher in the young age groups than in-adults. The highest positive rate was 18.4% in the age group less than 10. 3) Of 14 water specimens sampled from Han River system and its tributaries around the Seoul area, the Giardia cysts were detected from 4 samples, and no cyst was found in the water supply systems. 4) The cysts treated in the sewage survived for 28 days at $4^{\circ}C$ and for 13 days at $25^{\circ}C$. 5) The cysts were completely destroyed within 60 minutes by exposure to 8 mg/l of residual chlorine at 4g and within 30 minutes by exposure to the same concentration of chlorine at $25^{\circ}C$. 6) The cysts were all dead when exposed to 1 mg/1 of iodine for 60 minutes at $4^{\circ}C$ or $25^{\circ}C$. 7) The cysts were destroyed after 10 minute exposure in 0.15 mg to 0.25mg of residual ozone gas per liter. Summarizing the above results, it is considered that Giardia infection is regarded as water-borne disease and the cysts are able to be controlled by the application with the disinfectants in the water supply systems.

• Korean Journal of Agricultural Science
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• v.7 no.2
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• pp.156-168
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• 1980

The air-center nozzles, being specially designed to supply air into the central part of water stream at seven levels of air volume, were tested for spray deposit pattern and flow-rate at each of the twelve pressure levels ranging from $0.35kg/cm^2$ (5 psi) to $6.33kg/cm^2$ (90 psi) in comparison with those of standard nozzles. The air-center nozzles produced comparatively more stable spray deposit patterns than the standard nozzles. The spray deposit patterns of the air-center nozzle were concentrated gradually in the central region with increase of air volume as a component of spray mixture. The degree of concentration of spray deposit on the central region from the air-center nozzle was higher than that of the standard nozzle, which suggested the possibility of obtaining farther travel distance spraying system at a given performance level. The flow rate of the air-center nozzle was not as much as that of the standard nozzle due to the air within certain limits. The rate of decrease of water flow became smaller with an increase in operating pressure although it changed rapidly in the beginning stage, ranging up to two or three percent of the air flow rate due to the compressive properties of air.

• Journal of The Korean Society of Grassland and Forage Science
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• v.21 no.3
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• pp.169-174
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• 2001

This study was conducted to investigate the effects of feed resources and collection system of nonconventional agricultural roughages, and reduction of environment pollution by turning non-conventional agricultural roughages to feed resources and diversification of feed supply. And a series of experiment were conducted to determine the effect of moisture control material on quality of sweet potato stalk, peanut stalk, barley straw, the experiments were conducted at Grassland and Forage Crops Division, National Livestock Research Institute, RDA, Suwon in 1999 and 2000. The results obtained from these experiments are summarized as follows; Acid detergent fiber(ADF), neutral detergent fiber(NDF) and total digestible nutrient(TDN) of sweet potato were 38.8, 50.7 and 58.2% in the control silage, but that of rice straw added silage for moisture control were decreased to 41.5, 50.8 and 56.1%. ADF, NDF, CP(crude protein) and TDN of peanut stalk were 42.2, 49.6, 10.5 and 55.6% on the rice straw added silage for moisture control, and there were not affected by barely straw added silage for moisture control. And ADF, NDF and TDN content of barely straw increased 42.8, 65.8 and 55.1% on the water+inoculants treated silage. The results of this study indicate that non-conventional agricultural roughages to feed resources should be make for silage at silo after dry matter percentage(ab0ut 35%) control. Also, rice straw added silage for moisture control will improve the silage fermentation and conservation. (Key words : Feed resources, Non-conventional agriculture, Fermentation, Inoculant, Rice straw)

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.35 no.5
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• pp.459-465
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• 2022

This paper reports a method to use a wireless sensor network deployed in the field to real-time monitor soil moisture, warning when the moisture level reaches a specific value, and wirelessly controlling an additional device (LED or water supply system, etc.). In addition, we report all processes related to wireless irrigation system, including field deployment of sensors, real-time monitoring using a smartphone, data calibration, and control of additional devices deployed in the field by smartphone. A commercially available open-source Internet of Things (IoT) platform, NodeMCU, was used, which was combined with a 9V battery, LED and soil humidity sensor to be integrated into a portable prototype. The IoT-based soil humidity sensor prototype deployed in the field was installed next to a tree for on-site demonstration for the measurement of soil humidity in real-time for about 30 hours, and the measured data was successfully transmitted to a smartphone via Wifi. The measurement data were automatically transmitted via e-mail in the form of a text file, stored on the web, followed by analyses and calibrations. The user can check the humidity of the soil real-time through a personal smartphone. When the humidity of a soil reached a specific value, an additional device, an LED device, placed in the field was successfully controlled through the smartphone. This LED can be easily replaced by other electronic devices such as water supplies, which can also be controlled by smartphones. These results show that farmers can not only monitor the condition of the field real-time through a sensor monitoring system manufactured simply at a low cost but also control additional devices such as irrigation facilities from a distance, thereby reducing unnecessary energy consumption and helping improve agricultural productivity.

• Proceedings of the Korea Water Resources Association Conference
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• 2021.06a
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• pp.186-186
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• 2021

농업가뭄은 관측과 예측이 용이하지 않고 정량적으로 나타내기도 어려운 자연현상이며, 우리나라의 경우 농업용수 이용량이 많고, 농업용 저수지, 양수장 등 이용형태가 다양하므로 강수 부족으로 농업가뭄이 발생한다고 해도 실제로 농업현장에서 느끼는 가뭄은 시·공간적으로 다를 수 있다. 농업용수 공급은 수문관리원이 경험을 통한 수문관리를 해오고 있으며, 그 방법 또한 정확한 계측이 아닌 경험으로 이루어지고 있어 공급량 관리가 정성적이고 제한적인 한계가 발생한다. 따라서, 수원공에서 수로조직 및 포장에 이르기까지의 용수공급 모의를 통해 농업용수 공급의 합리적인 분배, 말단 수로 및 포장까지 안정적인 용수공급을 위한 물공급 및 분배 효율 분석이 필요하다. 또한, 기존 농업용 수리시설물의 물 공급 능력 평가 및 들녘단위의 평야부 물 부족지역과 과잉공급된 지역의 정확한 파악을 위한 연구가 필요하다. 따라서, 농업용 저수지 및 양수장의 주목적인 관할 수혜구역에 대한 농업용수공급 안정성 및 관개효율을 평가하고자 한다. 본 연구에서는 상주지역의 덕가 저수지를 대상으로 양수장 위치에 따라 가상의 3가지 용수공급 시나리오를 구성하고 각 시나리오별 수로 네트워크 모의를 통해 평야부의 공급량 및 관개효율을 비교 분석하고자 한다. 2017년부터 2019년까지 농업기반시설관리시스템 (Rural Infrastructure Management System, RIMS) 저수율 데이터를 구축하였고, 유체의 흐름에 대한 수리적 특성을 모의할 수 있는 SWMM(Storm Water Management Model) 모형을 통해 관개기 동안의 농업용수 분배 모의와 공급효율을 분석하고자 한다.

• Journal of the Korean association of regional geographers
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• v.3 no.2
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• pp.37-87
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• 1997

As a results of researches on the cultivation processes and settlement developments on the Mangyoung river valley as a whole could be have four 'Space-Time Continuity' through a [Origin-Destination] theory model. On a initial phases of cultivation, the cultivation process has been begun at mountain slopes and tributory plains in upper part of river-basin from Koryo Dynasty to early Chosun Dynasty. At first, indigenous peasants burned forests on the mountain slopes for making 'dryfield' for a cereal crops. Following population increase more stable food supply is necessary facets of life inducing a change production method into a 'wetfield' in tributory plains matching the population increase. First sedentary agriculture maybe initiated at this mountain slopes and tributory plains on upper part of river basin through a burning cultivation methods. Mountain slopes and tributory plains are become a Origin area in cultivation processes. It expanded from up to down through the valleys with 'a bits of land' fashion in a steady pace like a terraced fields expanded with bit by bit of land to downward. They expanded their land to the middle part of river basin in mid period of Chosun Dynasty with dike construction techniques on the river bank. Lower part of river cultivated with embankment building techniques in 1920s and then naturally expanded to the tidal marshes on the estuaries and river inlets of coastal areas. 'Pioneer fringes' are consolidated at there in modern times. Changes in landscapes are appeared it's own characters with each periods of time. Followings are results of study through the Mangyoung river valley as a whole. (1) Mountain slopes and tributory plains on the upper part of river are cultivated 'dryfields' by indigenous peasants with Burning cultivation methods at first and developed sedentary settlements at the edges of mountain slopes and on the river terrace near the fields. They formed a kind of 'periphery-located cluster type' of settlement. This type of settlement are become a prominant type in upper part of river basin. 'Dryfields' has been changed into a 'wetfields' at the narrow tributory plains by increasing population pressure in later time. These wetfields are supplied water by Weir and Ponds Irrigation System(제언수리방법). Streams on the tributory plains has been attracted wetfields besides of it and formed a [water+land] complex on it. 'Wetfields' are expanded from up to downward with a terraced land pattern(adder like pattern, 붕전) according to the gradient of valley. These periphery located settlements are formed a intimate ecological linkage with several sets of surroundings. Inner villages are expanded to Outer villages according to the expansion of arable lands into downward. (2) Mountain slopes and tributory plains expanded its territory to the alluvial deposited plains on the middle part of river valley with a urgent need of new land by population increase. This part of alluvial plains are cultivated mainly in mid period of Chosun Dynasty. Irrigation methods are changed into a Dike Construction Irrigation method(천방수리방법) for the control of floods. It has a trend to change the subjectives of cultivation from community-oriented one who constructed Bochang along tributories making rice paddies to local government authorities who could be gather large sums of capitals, techniques and labours for the big dike construction affairs. Settlements are advanced in the midst of plains avoiding friction of distances and formed a 'Centrallocated cluster type' of settlements. There occured a hierarchical structures of settlements in ranks and sizes according merits of water supply and transportation convenience at the broad plains. Big towns are developed at there. It strengthened a more prominant [water+land] complex along the canals. Ecological linkages between settlements and surroundings are shaded out into a tiny one in this area. (3) It is very necessary to get a modern technology of flood control at the rivers that have a large volume of water and broad width. The alluvial plains are remained in a wilderness phase until a technical level reached a large artificial levee construction ability that could protect the arable land from flood. Until that time on most of alluvial land at the lower part of river are remained a wilderness of overgrown with reeds in lacks of techniques to build a large-scale artificial levee along the riverbank. Cultivation processes are progressed in a large scale one by Japanese agricultural companies with [River Rennovation Project] of central government in 1920s. Large scale artificial levees are constructed along the riverbank. Subjectives of cultivation are changed from Korean peasants to Japanese agricultural companies and Korean peasants fell down as a tenant in a colonial situation of that time in Korea. They could not have any voices in planning of spatial structure and decreased their role in planning. Newly cultivated lands are reflected company's intensions, objectives and perspectives for achieving their goals for the sake of colonial power. Newly cultivated lands are planned into a regular Rectangular Block settings of rice paddies and implanted a large scale Bureaucratic-oriented Irrigation System on the cultivated plains. Every settlements are located in the midst of rice paddies with a Central located Cluster type of settlements. [water+land] complex along the canal system are more strengthened. Cultivated space has a characters of [I-IT] landscapes. (4) Artificial levees are connected into a coastal emnankment for a reclamation of broad tidal marshes on the estuaries and inlets of rivers in the colonial times. Subjectives of reclamation are enlarged into a big agricultural companies that could be acted a role as a big cultivator. After that time on most of reclamation project of tidal marshes are controlled by these agricultural companies formed by mostly Japanese capitalists. Reclaimed lands on the estuaries and river inlets are under hands of agricultural companies and all the spatial structures are formed by their intensions, objectives and perspectives. They constructed a Unit Farming Area for the sake of companies. Spatial structures are planned in a regular one with broad arable land for the rice production of rectangular blocks, regular canal systems and tank reservoir for the irrigation water supply into reclaimed lands. There developed a 'Central-located linear type' of settlements in midst of reclaimed land. These settlements are settled in a detail program upon this newly reclaimed land at once with a master plan and they have planned patterns in their distribution, building materials, location, and form. Ecological linkage between Newly settled settlemrnts and its surroundings are lost its colours and became a more artificial one by human-centred environment. [I-IT] landscapes are become more prominant. This region is a destination area of [Origin-Destination] theory model and formed a 'Pioneer Fringe'. It is a kind of pioneer front that could advance or retreat discontinously by physical conditions and socio-cultural conditions of that region.

• Journal of Soil and Groundwater Environment
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• v.17 no.2
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• pp.37-46
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• 2012

This study was conducted to identify groundwater recharge and discharge amounts of a representative urban-rural composite area located in Yongin city, Kyounggi-do, Korea. Groundwater recharge would be affected by mainly two processes in the study area: rainfall and leakage from public water pipelines including water-supply and sewage system. Groundwater recharge rate was estimated to be 13.5% by applying annual groundwater level data from two National Groundwater Monitoring Stations to the master regression curve method. Subsequently, the recharge amounts were determined to be $13,253{\times}10^3m^3/yr$. Leakage amounts from water-supply and sewage system were estimated to be $3,218{\times}10^3$ and $5,696{\times}10^3m^3/yr$, respectively. On the whole, a total of the recharge amounts was $22,167{\times}10^3m^3/yr$, of which 60% covers rainfall recharge and 40% pipeline leakage. Groundwater discharge occurred through three processes in the composite area: baseflow, well pumping, and discharge from urban infrastructure including groundwater infiltration into sewage pipeline and artificial extraction of groundwater to protect underground facilities from submergence. Discharge amounts by baseflow flowing to the Kiheung agricultural reservoir and well pumping were estimated to be $382{\times}10^3$ and $1,323{\times}10^3m^3/yr$, respectively. Occurrence of groundwater infiltration into sewage pipeline was rarely identified. Groundwater extraction amounts from the Bundang subway line as an underground facility were identified as $714{\times}10^3m^3/yr$. Overall, a total of the discharge amounts was determined to be $2,419{\times}10^3m^3/yr$, which was contributed by 29% of artificial discharge. Even though groundwater budget of the composite area was identified to be a surplus, it should be managed for a sound groundwater environment by changing deteriorated pipelines and controlling artificial discharge amounts.