• Korean Journal of Agricultural Science
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• v.40 no.3
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• pp.237-241
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• 2013

This study started to export an orchard tractor to Europe under the situations that R&D activities for orchard tractor were marginal and even it was not produced. The R&D for orchard tractor has been progressed and the most of it is accomplishing the goal. In this study, the durability of clutch friction part was tested for F/R clutch and moment of inertia of PTO clutch, and it was compared with the design criteria of transmission of tractor. According to the results of inertia test of F/R clutch, hydraulic pressures of clutch satisfied $1,961.33{\pm}196.13kPa$ of design criteria, and the variations of torque for forward and reverse operation were relatively constant. Therefore, it was found that the durability of clutch friction part was stable and reliable. Test results showed that the main hydraulic pressures were maintained $1,961.33{\pm}196.13kPa$ during the tests of moment of inertia of PTO clutch, and when it was operated, the hydraulic pressures were reached $1,961.33{\pm}196.13kPa$. Therefore, it was found that the hydraulic pressures of PTO satisfied the design criteria. By the results that the time of the hydraulic pressures of PTO reaching main hydraulic pressure, and that of torque values restoring to the original was same as the time of the first gear of PTO reaching the maximum rotational speed, it was found that PTO could transfer power to attachments as it was designed.

• Proceedings of the Korean Society for Agricultural Machinery Conference
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• 2001.07a
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• pp.103-108
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• 2001

• Proceedings of the Korean Society for Agricultural Machinery Conference
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• v.11 no.2
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• pp.15-18
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• 2006

• Proceedings of the Korean Society for Agricultural Machinery Conference
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• v.11 no.1
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• pp.5-11
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• 2006

• Proceedings of the Korean Society for Agricultural Machinery Conference
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• v.11 no.1
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• pp.12-20
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• 2006

• Proceedings of the Korean Society for Agricultural Machinery Conference
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• v.10 no.2
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• pp.68-73
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• 2005

• Journal of Biosystems Engineering
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• v.43 no.2
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• pp.83-93
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• 2018

Purpose: This study derived the consumed power and load characteristics of a tillage operation performed in an upland field located in Seomyeon, Chuncheon, Rep. Korea, where potatoes and cabbages were cultivated in two crops. Methods: A plow and rotavator were mounted on a tractor with 23.7 kW of rated power to perform the tillage operation. The work conditions were determined, considering the actual working speed of the tillage operation performed by the local farmers. The power consumption of the rear axle, engine, and power take-off (PTO), PTO torque, and tractive force were measured under each work condition. The consumed power and load characteristics were analyzed using their average values. Results: The rotary-tillage operation consumed more engine power than the plow operation for the same tractor-transmission gear condition. The PTO in the rotary-tillage operation and the rear axle in the plow operation consumed the most power. The power consumption of the engine and the PTO for the rotary-tillage operation tended to increase as the transmission gears of the tractor and the PTO became higher. In contrast, the rear-axle power consumption was insignificant. In addition, the PTO torque tended to rise as the tilling pitch increased. For the plow operation, the drawbar power and the rear axle power accounted for 68-90% of the engine power. The engine and rear axle power, drawbar power, and tractive force tended to rise as the working speed increased. Conclusions: The power consumption and load characteristics differed for the plow and rotary-tillage operations. They may also differ depending on the soil conditions. Therefore, the power consumption and load characteristics in various work environments and regions should be analyzed, and reflected in the design of tractors and working implements. The results derived from this study can be used as a reference for such designs.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.19 no.1
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• pp.89-99
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• 2020

This study analyzed the load and the consumed power characteristics of a potato harvesting operation in a dry field. The potato harvesting operation was performed using an underground crop harvester mounted on an agricultural tractor with a rated engine power of 23.7 kW. The rotational speeds and the torque of the engine output shaft, rear axle, and power take-off (PTO) shaft were measured under various working conditions. The load spectrum and the consumed power were analyzed using the measured data. The results show that the consumed power of the rear axle increased as the working speed increased, while that of the PTO shaft decreased. The consumed power of the engine output shaft showed a similar trend with that of the PTO shaft, but the torque deviation was larger in the load spectrum. The results of previous studies were used to compare herein the consumed power and the load characteristics of the harvesting, rotary, and plow operations in a dry field. PTO and tractive power were highly consumed in the plow and rotary operations, respectively. The consumed power of the PTO shaft and the rear axle in the harvesting operation were 29-41% and 18-23% of the engine power, respectively. Compared to those in the rotary and plow operations, the engine power was relatively evenly distributed to the PTO shaft and rear axle in the harvesting operation.

• Tuberculosis and Respiratory Diseases
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• v.82 no.2
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• pp.143-150
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• 2019

Background: The purpose of this study was to analyze the relationship between the gene mutation patterns by the GenoType MTBDRplus (MTBDRplus) assay and the phenotypic drug susceptibility test (pDST) results of isoniazid (INH) and prothionamide (Pto). Methods: A total of 206 patients whose MTBDRplus assay results revealed katG or inhA mutations were enrolled in the study. The pDST results were compared to mutation patterns on the MTBDRplus assay. Results: The katG and inhA mutations were identified in 68.0% and 35.0% of patients, respectively. Among the 134 isolated katG mutations, three (2.2%), 127 (94.8%) and 11 (8.2%) were phenotypically resistant to low-level INH, high-level INH, and Pto, respectively. Among the 66 isolated inhA mutations, 34 (51.5%), 18 (27.3%) and 21 (31.8%) were phenotypically resistant to low-level INH, high-level INH, and Pto, respectively. Of the 34 phenotypic Pto resistant isolates, 21 (61.8%), 11 (32.4%), and two (5.9%) had inhA, katG, and both gene mutations. Conclusion: It is noted that Pto may still be selected as one of the appropriate multidrug-resistant tuberculosis regimen, although inhA mutation is detected by the MTBDRplus assay until pDST confirms a Pto resistance. The reporting of detailed mutation patterns of the MTBDRplus assay may be important for clinical practice, rather than simply presenting resistance or susceptibility test results.

• The Journal of the Korea institute of electronic communication sciences
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• v.17 no.4
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• pp.617-624
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• 2022

The small electric vehicles equipped with V2X(vehicle to everything) systems may provide more information and function to the existing navigation system of the vehicle. The key components of V2X technology include V2V (vehicle to vehicle), V2N(vehicle to network) and V2I (vehicle to infrastructure). This study is to design and implementation of VI type E-PTO which is interfaced with external equipments, the work designs the components of E-PTO such as DC/DC converter, DC/AC converter, battery bidirectional charging system etc. Also, it implements the devices and control systems for driving. The test results of VI type E-PTO components showed allowable 10% requirements of transient voltage variation rate and recovery time within 100ms for start/stop and normal operation.