• Journal of Biosystems Engineering
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• v.35 no.3
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• pp.206-213
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• 2010

The purpose of this study is to analyze musculoskeletal injuries in combine harvesting operation using a digital human model. In order to analyze problems in combine harvesting operation, the operations were broken into 5 work processes and then we preformed ergonomic and biomechanical analyses such as RULA test, Comfort Assessment and joint kinetic analysis for the each process. As a result, there was a clear need to change the combine operating environment, as the RULA score ranged from 4 to 7. In addition, we could find two major musculoskeletal injury factors which are the standing posture with upperbody forward tilting and inappropriate location of operating levers.

• Journal of Biosystems Engineering
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• v.33 no.3
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• pp.157-166
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• 2008

Protected horticulture is labor-intensive. It necessitates great amount of labor in many tasks including grafting, pollination and harvesting. Particularly, carrying crops involves the most intensive labor which leads to a high risk of musculoskeletal disorder. Thus, this study aims at developing an ergonomic vehicle to reduce this intensity of labor and ergonomic evaluation by applying the newly developed vehicles to REBA. 5 healthy male subjects with no records of any musculoskeletal disorder were participated in this study. The experimental units were divided into three categories: lifting, lowering and pushing tasks. The results showed that the developed vehicle received less loads in group B (arms and wrists) than in group A (trunk, neck and legs). Especially, the developed vehicle scored $1.0{\sim}4.4$ in group C on REBA while the conventional wheelbarrow got $3.0{\sim}7.6$, regardless of working postures. In conclusion, the developed ergonomic vehicle provided less loads for human bodies compared to the conventional one.

• Journal of Biosystems Engineering
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• v.34 no.1
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• pp.57-62
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• 2009

Kinematic analysis of MTC (Muscle-Tendon Complex) units is a key indicator for diagnosis of patients with musculoskeletal disorders because the contracture or shortening of musculo-tendinous units is known to produce pathological gaits. Therefore, the principal objective of this study was to assess the length change in the triceps surae prior to and after wearing an AFO (Ankle-Foot Orthoses) in patients with musculoskeletal disorders during a gait. In this study, analyses were conducted using a Muscle Tendon Complex model coupled with the trajectory data from markers attached to anatomical landmarks. As a result, the maximum length change in the triceps surae during a gait was 4.87% when a barefoot walking group and a walking group with AFO were compared. In particular, the difference in length changes between both groups in Soleus MTC units was found to be statistically significant in all gait phases. Our results revealed that MTC length in the AFO walking group was clearly increased over that of the barefoot walking group. In the future, further studies will be required in order to more adequately assess musculoskeletal disorders using many cases studies with regard to agricultural working conditions because this study deals with the kinematic analysis of musculo-tendinous units in the case of clinical experiments.

• Journal of Biosystems Engineering
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• v.34 no.4
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• pp.286-294
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• 2009

A high prevalence of protected horticulture farmer's work-related musculo-skeletal disorders (MSDs) have been reported in precedent studies. One of the tasks required ergonomic intervention to reduce the musculo-skeletal risks is the task of product transporting. The purpose of this study is to evaluate quantitatively the spinal load of operator using manual vehicles to predict and prevent musculo-skeletal risks. Spinal load in operators using 4 kinds of manual vehicle were analyzed. Before evaluating spinal load on operator using the manual vehicles by bio-mechanical approach, it is needed to validate human model. In this study, ADAMS LifeMOD human model shows satisfactory results, comparing with already validated model's results or measured results. While Operators pushed the manual vehicles(wheelbarrow, Trolley, 2 wheel cart, and 4 wheel cart) contained loads that were 0 N and 800 N, their spinal loads(compression force, shear force) were evaluated. The compression force demonstrated under the NIOSH action limits - 3410N - for all 4 manual vehicle's operators(McGill 1997; Marras 2000). However, the lateral shear force demonstrated over the University of Waterloo - 500N - for all 3 manual vehicle's operators except 4Wheel cart (Yingline and McGill, 1999). Therefore, operators have risks in prevalence of the musculo-skeletal disorders due to shear force. The findings of this study suggest that it need to be determine the spinal load, especially lateral shear force in designing the manual vehicles in the future.

• Proceedings of the Korean Society for Agricultural Machinery Conference
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• 2017.04a
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• pp.55-55
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• 2017

본 연구는 파프리카를 자동 수확하기 위한 시스템 개발의 일환으로 수확작업기의 절단장치를 설계하고자 파프리카 과병의 절단특성을 분석하고자 하였다. 파프리카 과병의 절단특성을 분석하기 위하여 사용한 파프리카는 경기도 평택시에서 재배된 파프리카를 사용하였다. 적색 품종인 Nagano RZ와 황색 품종인 Helsinki, 주황색 품종인 Boogie를 사용하였다. 파프리카 과병의 절단 특성을 분석하기 위하여 상기 세 가지 품종의 파프리카 30개씩 총 90개의 파프리카를 사용하여 과병의 중앙 지점을 절단하였다. 절단 특성을 측정하기 위하여 push-pull gauge인 digitect dtg-20을 사용하였으며, 파프리카의 과병의 절단 특성을 측정하기 위하여 일반 농가에서 사용하는 접도 OLFA CK2의 접도의 칼날을 digitect dtg-20에 장착하여 측정하였다. 파프리카 과병의 절단 특성의 시험 항목은 절단강도를 측정하였다. 파프리카의 과병의 절단 특성 측정은 수확작업기의 파프리카 과병의 절단을 위한 절단장치의 설계를 위하여 진행하였다. 파프리카 과병의 절단 특성은 파프리카의 훼손을 최소화한 수확작업을 위한 중요한 요소이다. 파프리카의 과병의 중앙을 절단하여 절단강도와 절단력을 측정하였다. 그 결과 파프리카 과병의 절단강도는 $4.18{\pm}1.18kgf$로 나타났으며, 최대값은 6.91kgf, 최소값은 2.26kgf로 나타났다. 파프리카 과병은 측정된 절단강도의 최대값인 6.91kgf보다 큰 힘을 이용하여 절단하여야 하므로 그에 맞게 수확작업기의 절단장치의 모터를 선정하고 설계가 이루어져야 한다고 판단한다.

• Journal of Biosystems Engineering
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• v.39 no.4
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• pp.290-298
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• 2014

Purpose: To ascertain the increase of the farm income that predominantly relies on human resources by mechanizing Welsh onion harvesting, a tractor-mounted Welsh onion harvester was developed in this study. Method: An experiment for evaluating harvesting performance was performed for the developed Welsh onion harvester in an actual Welsh onion farm. The harvest performance was evaluated at the tractor running speeds of 5.0 cm/s, 11.4 cm/s and 15.8 cm/s, by comparing the operating efficiency, harvest rate, and damage rate of the Welsh onion harvester. Results: The performance of the harvester was rated as very good, with a 100% harvest rate, regardless of tractor running speed. Furthermore, it is shown that work efficiency of the harvester is expected to increase as the running speed increases. Nonetheless, the damage rate of the harvested Welsh onions at running speeds 5.0 cm/s, 11.4 cm/s, and 15.8 cm/s, increased correspondingly and proportionally to speeds from 4.55% to 6.53% and to 11.29%. The residual amount of soil on the harvested Welsh onions was about 0.24% of their weight showing excellent soil-removal performance of the harvester. Conclusion: The developed Welsh onion harvester is believed to improve the labor productivity and cultivation environment of Welsh onion farmhouses by the mechanization of the harvesting process that is currently associated with the largest amount of labor hours.

• Journal of Biosystems Engineering
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• v.32 no.5
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• pp.284-291
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• 2007

This study was to investigate performance of position, basic controls and additional control for man-machine interface on a 3-point hitch of a tractor. The developed additional control was one-touchup, backup, turnup, liftarm limited, PTO on/off and an external control. As a result of experiment, maximum steady state error of response system was lower than $0.8^{\circ}$ and this result showed the function operated normally because the dead band of system set was ${\pm}1^{\circ}$. There was no abnormal situation by switch operation and sensor signal during the performance test. The results of experiment showed the characteristics of the response was sufficient to be used as the position and additional control system for tractors.

• Journal of Biosystems Engineering
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• v.36 no.1
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• pp.58-67
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• 2011

A high prevalence of protected horiculture farmer's work-related musculo-skeletal disorders (MSDs) have been reported in precedent studies. One of the tasks required ergonomic intervention to reduce the musculo-skeletal risks is the task of harvesting. The purpose of this study is to evaluate quantitatively the spinal load of worker harvesting with squatting posture to predict and prevent musculo-skeletal risks. Spinal load in Squatting posture with asymmetric trunk motion were analyzed. Before evaluating spinal load on harvesting worker by bio-mechanical approach, it is needed to validate human model. In this study, ADAMS LifeMOD human model shows satisfactory results, comparing with already validated model's results or measured results. While worker reached arms (20%, 40%, 70% arm reach) with various asymmetric trunk motion (0, 45, 90 degree), their spinal loads (extension, twisting and lateral bending moment) were evaluated. In case of extensor moment at lumbo-sacral joint, the more the arm reach got increased, the moment increased. however, in case of twisting moment and lateral bending moment, the more both arm reach and asymmetric trunk motion got increased, the moment increased significantly. The findings of this study suggest that it need to be determine the spinal load, especially twisting, lateral bending moment in evaluating musculo-skeletal workload in squatting posture.

• Journal of Biosystems Engineering
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• v.41 no.3
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• pp.161-169
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• 2016

Purpose: To improve the insufficient mechanized forage harvesting system, an integrated forage harvester that produces midsize round bales was developed. Methods: The harvesting performance of the developed harvester was tested in a forage plantation. The harvesting performance was evaluated by investigating the bale production performance and residue ratios of the harvester at three levels of tractor driving speeds. Results: The bales outputs per hour by driving speed shown by the harvester were 30 bales (6.8 MT) at 2.3 km/h, 36 bales (8.4 MT) at 3.2 km/h, and 44 bales (10.5 MT) at 5.1 km/h in the case of rye-straw. In the case of rice-straw, they were 43 bales (8.8 MT) at 4.3 km/h, 44 bales (9.7 MT) at 5.0 km/h, and 48 bales (10.7 MT) at 6.2 km/h. In the case of Italian ryegrass (IRG), they were 35 bales (10.7 MT) at 7.0 km/h, 37 bales (12.0 MT) at 8.3 km/h, and 38 bales (13.2 MT) at 9.5 km/h. The average ratios of residues to the available quantities were 2.61% in the case of rye-straw, 1.89% in the case of rice-straw, and 1.57% in the case of IRG. When residues smaller than 200 mm, which cannot be collected, were excluded, the residue ratios of all crops were good, as they did not exceed 1.0%. Conclusions: Since the baling and wrapping functions, which had been separately operated, were integrated into the developed harvester, the developed harvester is expected to maximize bale production efficiency and increase labor productivity, thereby increasing farming profitability.

• Journal of agriculture & life science
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• v.50 no.5
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• pp.217-224
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• 2016

In this study, performance of a developed automatic punching machine considering the planting density of soybeans was evaluated in the case of the operation speed of 0.18-0.28 m/s. The performance demonstrated a rate of 320-500 ㎡/h, 260-400 ㎡/h, and 210-330 ㎡/h for the 0.20 m, 0.25 m, and 0.30 m soybean planting density, respectively. One hundred percent punching capacity was confirmed in 30 mm distance between the ground and the blade. Additionally, in the 50 mm distance condition, the performance of round, square, and hexagonal blades were observed in the range of 16.7-25.2%, 33.0-42.3%, and 54.5-100.0%, respectively. Above all, the hexagonal blade with a 60° edge angle had the most superior cutting quality demonstrating a smooth and soft cutting plane of the plastic.