• Journal of Biosystems Engineering
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• v.34 no.1
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• pp.21-29
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• 2009

A rapeseed reaping equipment attachable to a conventional combine was developed in order to harvest rapeseed for bio-diesel materials. This study was carried out to measure the harvest feasibility of a prototype combine in rapeseed fields. Grain, stem and pod flow rate, grain qualities (whole kernel, damaged kernel, unhulled kernel, material-other-than-grain) and grain loss rates (header, threshing, separation) were investigated in each field test. As the result of the fold test, the average grain flow rates of SUNMANG and MS varieties showed 1,430 kg/h and 2,038 kg/h, respectively. The average stem and pod flow rates showed 3,443 kg/h and 6,596 kg/h, respectively. In each working speed, the average whole kernel rate and the material-other-than-grain showed 99.9% and below 0.08%, respectively. In the average grain loss, the rates showed 5.66% in case of SUNMANG and 5.94% in MS. Header loss was higher than other parts for SUNMANG. However, threshing loss was relatively higher than other parts for MS. Header loss rate due to side cutter knifes, however, was not so high when compared with a grain loss due to the cutter bar. Effective field capacity and field efficiency of the prototype combine showed 0.389 ha/h and 44%, respectively. Comparison of customary combine with the prototype combine through field test demonstrated that the header loss was reduced by 69.3% when the prototype combine was used.

• Journal of Biosystems Engineering
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• v.15 no.4
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• pp.310-318
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• 1990

The amount of grain loss incurred during harvesting operation through the chaff-outlet of combine may not be negligible. To minimize this grain loss and optimize condition of combining, it may be necessary that the amout of chaff-outlet loss dependent on varying crop condition is to be estimated as exactly as possible. This study was thus intended to develop the monitor that could indicate the amount of grain lost through the chaff-outlet of combine during haravesting operation, and to find out driving and operating method of combine that could reduce chaff-outlet loss. In the study(1), the frequency distributions of each sound generated by the impact of kernels and chaff, the sound generated by the impact of the mixture of kernels and chaff, and vibration or noise created by the combine engine and other moving parts were investigated experimentally. Based on the results of frequency analyses, the loss monitor was developed which could measure the impact sound of paddy kernels that could be distinguished from those of other threshing products through chaff-outlet, and from vibration or noise created by the combine engine and other moving parts. Also in this study, detecting capability of monitor was tested by comparing the amount of grain lost through chaff-outlet with the amount of grain detected by the loss monitor, and changes in chaff-outlet grain loss on the increase of traveling speed, location of chaff-outlet loss control plate and variety of paddy rice were measured using the loss monitor. The monitor developed in this study efficiently measured the amount of grain lost through the chaff-outlet of combine. It was found that the chaff-outlet grain loss ratio was affected greatly by the variety of paddy rice, the location of chaff-outlet loss control plate and traveling speed of combine.

• Journal of Biosystems Engineering
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• v.43 no.4
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• pp.296-302
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• 2018

Purpose: The aim of this study was to determine appropriate threshing and selection conditions for sorghum harvesting using a rice combine-harvester. Methods: Sorghum harvesting performance was tested using an actual rice combine. Through this test, the grain loss rate and the composition of crops according to the engine and fan speeds of the combine were investigated. Furthermore, the optimal threshing and selection conditions were determined by carrying out a harvest test based on the opening size factor of the concave in a test field. Results: The grain loss rate for the sorghum using a concave ($18{\times}18mm$) of the rice combine was the lowest at 0.1% at a chaffer angle of $40^{\circ}$, engine speed of 2000 rpm, and fan speed of 20 m/s, but the sorting sieve clogged frequently. Furthermore, as the engine speed and fan speed increased, the grain loss rate also increased. The sorghum harvesting test results of the combine according to the concave opening size showed that the grain loss rate was 0.5% at a driving speed of 0.5 m/s, with a concave opening diameter of 13 mm, a chaffer angle of $40^{\circ}$, a concave sieve oscillation frequency of 4.8 Hz, a fan speed of 20 m/s, and an engine speed of 2000 rpm. Conclusions: Findings showed that sorghum could be harvested using a head feeding rice combine.

• 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.

• Proceedings of the Korean Society for Agricultural Machinery Conference
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• 1993.10a
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• pp.1264-1272
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• 1993

The software for unmanned control of three row typed rice combine has been developed using fuzzy logic. Three fuzzy variables were used : operating status of combine, steering, and speed. Eleven fuzzy rules were constructed and the eleven linguistic variables were used for the fuzzy rules. Six sensors were use of to get input values and sensor input values were quantified into 11 levels. The fuzzy output was infered with fuzzy inferrence which uses the correlation product encoding , and it must have been defuzzified by the method of center of gravity to use it for the control. The result of performance test using graphic simulation showed that the intelligently unmanned control of a rice combine was possible using fuzzy logic control.

• Proceedings of the Korean Society for Agricultural Machinery Conference
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• 1993.10a
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• pp.752-760
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• 1993

We research ed on the noise control of a head feeding type combine harvester. It is a kind of combine harvester developed in Japan. And at present, it is used by most Japanese farmer. For a head-feeding type combine harvester it is very difficult to determine the sources of noise because it is a combination of reapers and automatic , threshers and several running parts. However we succeeded in finding out the sound sources of combine harvesters and analyzing their sound by the using sound intensity method. The sound intensity Method is a very up-to-date method to measure and analyze Sound Intensity Levels and sound directions at several measuring point sin a specified area. In this research, first a conventional sound level measurement method is used and secondly the sound intensity method. The first method shows a rather great limitation in allowed exposure duration. The second method shows pin-points the engine itself as being the main source of noise, causing sound flows a ross the operator's seat.

• Korean Journal of Agricultural Science
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• v.33 no.2
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• pp.159-166
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• 2006

Threshing loss was increased due to dropping of the threshing efficiency when the 4 row head-feed combine harvested 5 row rice to improve harvesting performance of a combine. Reasonable design criteria were examined to determine the ranges of both of feed rate and the length of threshing drum for the 4 row head-feed combine being used as a 5-row combine. Harvesting performance increased as working width or working speed increased, it resulted in 15% increase when the working width increased from 4 row to 5 row. Harvesting operations of the 4 row combine performed normally in the 4 row rice in threshing loss less than 1%, however, threshing loss increased to 2.25% in the 5 row due to poor threshing efficiency. The length of threshing drum was increased from 710 mm to 810 mm as well as the speed of crop feed chain was increased from 0.61 m/s to 0.75 m/s so as to improve the poor threshing efficiency resulted from the enlarged working width from the 4 row to the 5 row, which would decrease threshing loss less than 1%.

• Journal of Korea Water Resources Association
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• v.40 no.1 s.174
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• pp.89-99
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• 2007

Uncertainty analysis is used to eliminate the climatic variables of input nodes and construct the model of an optimal type from COMBINE-GRNNM-GA(Type-1), which have been developed in this issue(2007). The input variable which has the lowest smoothing factor during the training performance, is eliminated from the original COMBINE-GRNNM-GA (Type-1). And, the modified COMBINE-GRNNM-GA(Type-1) is retrained to find the new and lowest smoothing factor of the each climatic variable. The input variable which has the lowest smoothing factor, implies the least useful climatic variable for the model output. Furthermore, The sensitive and insensitive climatic variables are chosen from the uncertainty analysis of the input nodes. The optimal COMBINE-GRNNM-GA(Type-1) is developed to estimate and calculate the PE which is missed or ungaged and the $ET_r$ which is not measured with the least cost and endeavor Finally, the PE and $ET_r$. maps can be constructed to give the reference data for drought and irrigation and drainage networks system analysis using the optimal COMBINE-GRNNM-GA(Type-1) in South Korea.

• Journal of Biosystems Engineering
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• v.32 no.3
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• pp.153-159
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• 2007

This study was conducted to measure and analyze the noise from a combine head. The combine head, comprised of a cutting knife assembly, pick-up chains, horizontally conveying chains and vertically conveying chains, had an overall sound level of 101 dBA. The sound levels of each component were, respectively, 98.3 dBA for the cutting knife assembly, 88.9 dBA for the pick-up chains, 79.8 dBA for the horizontally conveying chains and 86.3 dBA for the vertically conveying chains, being equivalent to 54.4%, 18.4%, 6.5% and 13.7% of the overall head noise. The main cause of the head noise was considered the impacts that the joint of the cutting knife assembly made with frame when it oscillated. The impact sound was also generated when the chain lug collided with the chain case. To reduce these impact sound, anti-vibration rubbers were installed on the knife assembly joint and the chain cases. It reduced the head noise by 4 dBA but the overall noise level of the combine head was still high. In order to protect the combine operators more effectively from the noise, a safety cab needs to be installed on the combine.

• Journal of Biosystems Engineering
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• v.40 no.1
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• pp.10-18
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• 2015

Purpose: The study was conducted to investigate the proper working conditions like the mesh size of the concave and the chaffer angle of the oscillating sieve, and the fan speed of the head-feeding rice combine for foxtail millet harvesting. Methods: The study aimed to determine the harvesting conditions for the rice combine harvester at a 0.5 m/s working speed and at $40^{\circ}$ and $55^{\circ}$ sieve chaffer angles. The harvesting loss of the foxtail millet based on the speed of the fan and the oscillating speed of the sieve was measured at three levels of fan speed and oscillating sieve speed. Results: The threshing rates of different foxtail millet varieties were 64.1~83.5% at a mesh size of 7 mm of the concave. In experimental foxtail millet harvesting, the optimal operating condition of the rice combine harvester included a $40^{\circ}$ sieve chaffer angle and a 4.8 Hz oscillating sieve (cleaning shoe) frequency. The grain loss was found to be lower at a $40^{\circ}$ than at a $55^{\circ}$ sieve chaffer angle. In field harvesting using the combine harvester, the lowest harvesting grain loss rate of the foxtail millet varieties ranged between 0.2~0.5% at a 7 mm mesh concave, $40^{\circ}$ chaffer angle, 4.8 Hz sieve frequency, and a 20 m/s fan speed at an engine speed of 2,000 revolutions per minute (RPM). Conclusions: Findings showed that foxtail millet could be harvested using the combine harvester.