• Proceedings of the Korean Society of Crop Science Conference
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• 1998.04a
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• pp.201-202
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• 1998

• Proceedings of the Korean Society of Crop Science Conference
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• 2004.04a
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• pp.292-293
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• 2004

• Proceedings of the Korean Society of Crop Science Conference
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• 2022.04a
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• pp.64-64
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• 2022

• Proceedings of the Korean Society of Crop Science Conference
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• 2022.04a
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• pp.35-35
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• 2022

• KOREAN JOURNAL OF CROP SCIENCE
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• v.23 no.3
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• pp.66-72
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• 1978

Cultural practices favoring the crops are one of the excellent weed control measures in upland crops. The primary cultural method for weed-management may include planting of weed-competitive cultivars, proper planting time and spacing, optimum rate and placement of fertilizer, crop rotation, mulching, and timely tillage. However, cultural method must be applied as a part of the program along with all other available means for controlling weeds since this method alone is not adequate. The efficient and economical weed control can only be achieved by combinating cultural, mechanical method that supplement each other into a weed management system. Intelligent selection of weed control, however, presuppose knowledge of the life history and growth requirements of the weed and its interaction with the environment.

• Korean Journal of Agricultural Science
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• v.45 no.1
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• pp.120-127
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• 2018

The rural labor force has gradually been decreasing due to the decrement of the farm population and the increment of the aging population. To solve these problems, it is necessary to develop and study autonomous agricultural machinery. Therefore, analyzing the dynamic behavior of vehicles in an autonomous agricultural environment is important. Until now, most studies on agricultural machinery, especially on ground vehicle dynamics, have been done by field tests. However, these field test methods are time consuming and costly with seasonal restrictions. A research method that can replace existing field test methods by using simulations is needed. In this study, we did basic research analyzing the effect of the travelling speed of a tractor on tire slip using simulation software. A tractor simulation model was developed based on field conditions following a straight path. The simulation was done for three ranges of speed: 20 - 30 km/h (considered the normal travelling speed range), 6 - 8 km/h (considered the plow tillage speed range) and 2 - 4 km/h (considered the rotary tillage speed range). The results of the simulation show that the slip ratio and slip angle values tended to increase as the traveling speed range of the tractor decreased. From the simulation results, it can be concluded that at low tractor speeds, it becomes more difficult to control the vehicle path. In future research, simulations will be done with various work environments such as a curved path as well as with various friction coefficient conditions, and the simulation results will be experimentally verified by applying them to an agricultural tractor.

• Korean Journal of Medicinal Crop Science
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• v.16 no.2
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• pp.69-73
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• 2008

Fields experiments were conducted to investigate the effect of various tillage depth (TD) on productivity and quality of C. auriculatum Royle ex Wight from 2005 to 2006. The length of vine was elongated in lower TD treatments as 50 cm longer in 10 cm TD than 30 cm TD, and stem diameter and dry weight had increased in the lower TD. Length, width, and weight of leaves showed the quantitive growth in the lower TD treatments, but the chlorophyll content had increased in the deeper TD treatments. Root number and length had increased in the deeper TD treatments, but the root diameter and decomposed root was increased in the deeper TD. The total yield of root showed the increasing tendency in the deeper TD treatments as 6.2 ton/ha in 10 cm TD and increased as $7{\sim}9%$ in the 20 cm TD treatments.

• Korean Journal of Agricultural Science
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• v.47 no.4
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• pp.1123-1134
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• 2020

The goal of this study was to develop an accelerated life test for an implement working pump for an agricultural tractor. The field experiments were conducted to measure the load of an implement working pump during major agricultural operations such as plow tillage, rotary tillage, baler operations, and wrapping operations. The measurement system for an implement working pump load was constructed using a pressure sensor, the engine rotational speed, and the hitch pump displacement. The measured implement working pump load was calculated as an equivalent load for each agricultural operation using the Palmgren-Miner rule, which is a cumulative damage method. The equivalent load was calculated using the total load data and peak load data when the total data included the operation of an implement working. The annual usage time of the agricultural tractor was applied to develop two integrated equivalent loads. The acceleration factor was calculated to develop an accelerated life test and was calculated from the two integrated equivalent loads, the maximum pressure, and the flow rate conditions of the hitch pump. In Korea, the warranty life of a tractor is 2,736 hours, and the time required for the test to guarantee the operational life of tractors was calculated as 7,561 hours. The acceleration factors were calculated as 453.6 and 38.3, respectively, from the total load data and peak load data. The fatigue test time can be shortened by 16.7 and 197.4 hours according to the result of the acceleration factors.

• Proceedings of the Korean Society of Agricultural Engineers Conference
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• 2003.10a
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• pp.571-574
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• 2003

Three sediment traps were placed at the toe of sloping fields in the alpine belt of Korea and sediment removal efficiency was estimated. Soil texture of the site was sandy soil and 5 runoff and sediment events were observed during 2002. Sediment was largely affected by both the amount and intensity of rainfall. Especially, rainfall intensity seemed to have profound effect on sediment yield from sloping sandy fields. Sediment removal of the sediments ranged widely from 266 kg/ha to 16,974 kg/ha depending on tillage method, slope and slope length, and amount and intensity of rainfall. Sediment removal efficiency was estimated to be more than 98.8%. It was suggested that rational combination of sediment trap and drainage channel might well contribute to control sediment discharge from alpine sloping fields.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.16 no.3
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• pp.45-53
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• 2017

Disc harrow-type composite working implements of tractors are able to work almost 15km/hr. Soil reversing and plowing of agricultural fields are thereby faster than the existing rotavator speed of 2.5 km/h. In Korea, its supply process is being delayed because of the traditional tillage method of rotavator plowing operations. To develop products suitable for the domestic environment, an analysis and inspection was performed on the products of advanced specifications. 3D modeling was performed on main parts and frames using 3D scanner.