• Magazine of the Korean Society of Agricultural Engineers
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• v.33 no.4
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• pp.52-60
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• 1991

This study was conducted to investigate the appropriate operation method minimizing the deviation between irrigation water demand and release from the reservoirs, and the simulation technique was used in the operation model. This model was applied to the grouped reservoirs system consisted of Dongsang, Daia and Keungchun reservoirs and Eowoo-weir in Chonbuk FLIA district. The results obtained in this study are summarized as follows; 1.The area above the Eowoo weir point was divided into 6 small watersheds, and daily inflows from each watershed were calculated by Tank model. It showed that the average annual runoff ratio was 40-60% respectively. 2.Based on the Blaney-Criddle formula daily water requirement of Chonbuk FLIA irrigation area was estimated, mean water requirement for paddy field during the irrigation period was 818.lmm. 3.Using the basic data such as inflow and water demand, four different release types were selected. Through the simulated operation the difference between intake water required at Eowoo-weir point and release from the 3 reservoirs was estimated. The best result was obtained when Daia and Keungchun reservoirs are operated parallelly at fixed release ratio and the release of Dongsang reservoir was determined according to the storage of Daia reservoir.

• Agricultural and Biosystems Engineering
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• v.6 no.2
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• pp.59-64
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• 2005

In the study, the cone index, the cohesion and the internal resistant angle of soil were measured before and after tillage in order to suggest relative improvement in soil properties. The tillage methods tested in the study were five combinations of plow and rotary tillage operation and the experiments were performed on five selected test fields. The maximum tillage depth was 20 cm under the ground. The CIs for all the tillage operations were improved in comparison with those before tillage. The best combination of tillage operations for improving the CIs of soil was one plow operation followed by one rotary. After applying the tillage operations, the internal resistance angle reduced by 7-8 degree and the cohesion decreased up to about $1N/cm^2$ in comparison with those before tillage. We concluded that the cone index, the cohesion and the internal resistant angle of soil could be used as measures for representing the relative degree of tillage for a specific tillage operation. In addition, the study was useful as a basic research tool for developing an decision making system that determines an optimal tillage method with soil properties.

• Proceedings of the Korean Society of Agricultural Engineers Conference
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• 2004.11a
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• pp.79-79
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• 2004

• Proceedings of the Korean Society of Agricultural Engineers Conference
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• 2002.10a
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• pp.137-140
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• 2002

The monitoring system for integrated management of on-site wastewater treatment plants(biofilter) was designed and its operation program was developed. In design process, the research on monitoring parameters which will be able to represent condition and operation of the pilot plants was accomplished, and these parameters came to reveal with ORP(Oxidation-Reduction Potential), water level, pump and power on/off. Proposed monitoring system is composed with measurement, control, communication and display device, and PCB(Prototype Circuit Boards) and microcontroller (PIC16F877) technique are applied to its design of control device for performing specific function. also, The operation program of PC setup is developed in order to provide a convenience to the manager.

• Magazine of the Korean Society of Agricultural Engineers
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• v.45 no.5
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• pp.67-76
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• 2003

The principal operation rule of irrigation reservoir is to accelerate the water use and supply water actively when water is sufficient, and to restrict water use and supply water deficiently in order not to stop the irrigation activity when water is scarce. In drought seasons. water should be saved in order to keep the reservoir not to be dried up during the irrigation season. It is important to know how much water should be saved, depending on the rice-growing season and water storage volume. For the drought control of irrigation reservoirs. the rotational irrigation scheduling in paddy with the operation rule curve developed in this study could be utilized as a software program to install TM/TC system for irrigation water supply by automation facilities.

• Proceedings of the Korean Society for Agricultural Machinery Conference
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• 1993.10a
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• pp.601-610
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• 1993

With the purpose of labour reduction in tea plucking operation with portable type machine, the influence of frame angles and tea leaves weight on the grasping forces of each finger were investigated. At the measurement of the grasping force of each finger except for thumb, grip strength dynamometers were attached at the grasping position of the frame instead of handle grips. A series of measurement was carried out changing frame angles of the tea plucking machine and the weight of tea leaves. With the obtained results of the experiments , the influences of the frame angles and the weight of the tea leaves on the grasping forces of each finger were analyzed. Some reasonable suggestions for the labour reduction in the tea plucking operation with portable type machine were obtained in the aspect of normalizing the balance of the grasping force on each finger and these suggestions are expected to contribute the labour reduction of the tea plucking operation.

• Magazine of the Korean Society of Agricultural Engineers
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• v.45 no.1
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• pp.91-101
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• 2003

Boryeong Seadike located at southwestern seashore of Korean peninsula completed in 1997. Sluice gate operation can be an important factor to maintain lake water quality and reduce retaining time of pollutants within lake. The lake water quality simulation model, WASPS was adopted and tested to find out proper gate operation timing and discharge amount. From the simulation of sluice gate operation, the results showed that the later the time of discharge for loosing 1 day successively to 6 days, the better the quality of water. Discharge amount showed relatively minor changes of water quality. This means that pollutants flowed into lake from watershed do not have enough time to mix up with deep water when the gate opened at early time. About 3 days delay of discharge caused the dilution effect to stabilize the lake water quality in case of Boryeong freshwater lake.

• Proceedings of the Korean Society of Agricultural Engineers Conference
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• 2005.10a
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• pp.260-265
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• 2005

The purpose of this study is to established a storage management method and operation standard for irrigation dams occupying the largest portion of small dams using storage management system. The system can be applied to seongju dam for effective management. The storage management method was established considering hydrology simulation and statistical analysis using the system. This method and operation standard are capable of analyzing additional available water, considering the water demand and supply of basin actually. It can improve the flood control capacity and water utilization efficiency by the flexible operation of storage space.

• Magazine of the Korean Society of Agricultural Engineers
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• v.36 no.3
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• pp.47-59
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• 1994

The irrigation reservoir operation models developed were tested with weather and field data, and the sensitivity of the water requirement deficiency indices(WRDI) were checked with different initial reservoir storages, irrigated areas, and other water uses from the reservoir storage. Seven reservoir release rules were applied to Yongseol Reservoir. Twenty year WRDIs were computed to check performances of those reservoir release rules. Mean WRDIs were 138, 198, 198, 200, 240, 344, and 1033mm for ROM, TOS, COS, CRR, MSC, FAS, and SRC, respectively. The results indicated that ROM contributes consistently to higher operation efficiencies of an irrigation reservoir. The test results of LFROM and SFROM showed that reservoir operation with the proposed optimization technique ROM would be better suited for an irrigation district than those with the other rules. And the proposed model could be used as a tool to improve reservoir operations.

• Proceedings of the Korean Society for Agricultural Machinery Conference
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• 1999.12a
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• pp.53-59
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• 1999