• Journal of Biosystems Engineering
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• v.2 no.1
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• pp.55-55
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• 1977

This experimental work was conducted in order to find out the optimum time of harvest of Japonica-type(Akibare) and Indica-type(Tong-il) rice variety for three harvesting systems by investigating the harvestirg losses and milling quality. The study was also concerned atout the nature and amount of grain losses incurred during the each sequence of post-harvest technologies, and based on these results, a modification of existing systems giving a minimum grain loss was attempted. Binder, combine, and traditional harvesting systems were tested in this study and five grain moisture levels were disposed according to the decrease of grain moisture. The results are summarized as follows: 1. The total losses of Akibare variety were ranged from 1.1 to 1.5 per cent for the traditional harvesting system, 2.1 to 4.8 percent for the harvesting system by use of binder, and 2.8 to 4.3 percent for the harvesting system by use of combine as the grain moisture content was reduced from 24 to 15 per cent. Milling recovery of the harvesting system by use of binder, 74.8~ 75.7 percent, was a little higher as it was compared to that of traditional harvesting system, 74. 3~75. 0 percent, and that of the harvesting system by use of combine, 73.8~ 75.0 per cent. Head rice recovery of mechanically dried paddy samples was higher than that of sun-dried paddy samples. 2. The total losses of Tong-il variety were ranged from 3.8 to 5.0 per cent for the traditional harvesting system, 5.2 to 10.0 percent for the system by use of binder, and 3.0 to 5.0 perent for the system by use of combine as the grain moisture was reduced from 28 to 16 percent.

• Journal of Biosystems Engineering
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• v.3 no.1
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• pp.33-46
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• 1978

To get the goal of self-supply of food grain, improvement of post-harvest grain operations in rural area is under consideration as an important task of agriculture in Korea. This is study is focused on elimination of losses and deteriorations of grain and reduction of labour requirements and funds for post-harvest grain operations. The purpose of this study are presentation of basic data referring to conventional post-harvest grain operations in rural area and suggestion of improving methods for the operations, and also finding out reasonable operating processes of the operations. The result of this study are follows; 1. Grain drying in-the-filed which is performed before threshing has major factors of grain loss during drying, and so should be restrained as possible. Combine harvesting system is recommended among other king of mechanized harvesting systems for restraining in-the-field drying and securing available labors for drying. 2. It is predicted that mechanical grain drying could be prevalent when combine harvesting is taken place. Recommended grain drier for pre-combine harvesting system and for combine harvesting system is batch-type drier and circulating -type drier, respectively. 3. As existing farm storages for grain have insufficient spaces and offer poor conditions for grain storing , it is greatly needed to build up new storage which store only grains. And it is concluded that storing grain in community common storages in desirable. 4. Power supplying system for milling machinery in local milling plants, that a large capacity prime mover supplies power to 4 to 6 kinds of milling machinery simultaeously, should be converted to a system of several small capacity prime movers supplying power to each machiner y for the purpose of reducing extra consumption of energy. 5. Governmental grain, of which Korean farms produced, should be milled and stored in the local milling plant successively for the purpose of reducing transportation fee and stroing facilities. 6. Furture post-havest grain operations-drying, storing and milling should be periormed successively in he community common plant. And average optimum processing capacity of the plant is estimated about 300 metric ton of grain every year.

• Journal of Biosystems Engineering
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• v.42 no.2
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• pp.80-85
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• 2017

Purpose: In this study, we attempted to analyze, by using a high-speed camera, the cutting shape as a function of cutting speed and feed rate. We compared the differences in cutting shape between domestic and foreign combines. Methods: Experiments were performed using plastic straws, and the results of two combine cutting blades, one from the Daedong Industry and one from Kuboda, were compared. The quality and performances of cutting were measured at three cutting positions: center and 68 cm to the left and right of the center. The feed rates were 0.6 m/s, 1.1 m/s, 1.6 m/s, and the cutting speeds were 600 RPM, 990 RPM, 1,380 RPM. For each speed, the cutting shape was measured three times, and the entire procedure was also repeated three times. Results: In the experiments, the domestic cutting blade achieved better results than the Japanese cutting blade. These results were obtained by studying the combination of feed rate and cutting speed, with the domestic combine attaining approximately 80% performance of the Japanese combine. We believe that additional data analysis is required, obtained from field experiments. Conclusions: The domestic cutting knives achieved better results than the Japanese cutting knives. These results are estimated from experiments conducted with different feed rates and cutting speeds; an in-depth analysis will require experiments in the real field with actual combines and a combination of multiple variables. Repeating the investigation on the length differences, broken and cut angle with various combinations of feed rate and cutting speed, will surely help to find the optimal cutting speed.

• Journal of Drive and Control
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• v.21 no.2
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• pp.36-43
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• 2024

The yield is basic and necessary information in precision agriculture that reduces input resources and enhances productivity. Yield information is important because it can be used to set up farming plans and evaluate farming results. Yield monitoring systems are commercialized in the United States and Japan but not in Korea. Therefore, such a system must be developed. This study was conducted to develop a yield monitoring system that improved performance by correcting a previously developed flow sensor using a grain tank-weighing system. An impact-plated type flow sensor was installed in a grain tank where grains are placed, and grain tank-weighing sensors were installed under the grain tank to estimate the weight of the grain inside the tank. The grain flow rate and grain weight prediction models showed high correlations, with coefficient of determinations (R2) of 0.9979 and 0.9991, respectively. A main controller of the yield monitoring system that calculated the real-time yield using a sensor output value was also developed and installed in a combine harvester. Field tests of the combine harvester yield monitoring system were conducted in a rice paddy field. The developed yield monitoring system showed high accuracy with an error of 0.13%. Therefore, the newly developed yield monitoring system can be used to predict grain weight with high accuracy.

• Journal of Biosystems Engineering
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• v.32 no.3
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• pp.197-205
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• 2007

The objective of this study was to design and implement a gateway for remote monitoring a combine. Many researchers have designed and implemented trouble-shooting system of agricultural machine. but the system didn't have network system or used wired network system. But monitoring machine have been operated in the out of door. In such an environment, each machine have to be operated under on a guarantee of mobility and stability. Thus, we have developed a gateway with an embedded system including the XScale PXA255 processor and wireless network device. We have also built an embedded Linux kernel and several devices. We developed an embedded application for monitoring a combine and this application is also capable of receiving signals from other clients and sending them to a server via Wireless LAN. Finally, results of performance evaluation which measured CPU share and memory sizes have shown that it is possible to provide monitoring service stably.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.36 no.1
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• pp.79-84
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• 1991

The rice plants (Oryza sativa L.) established from the shattered grains by combine harvesting at the previous year showed great variations of yield and yield components from site to site at the abandoned rice crop field. The cultural condition was very similar to direct seeding under no-tillage system but no cultural practices such as application of fertilizer, weed control, irrigation and drainage had been carried out. The highest yield of 188kg/10a was observed at one of the quadrats randomly located on the field, which showed the possibility of exploitation of no-tillage system. The interrelationship between crop growth and coverage of weed species was measured by calculating the correlation coefficients. The investigations of how to establish sufficient number of seedlings per unit area, plant succession on the abandoned crop field, crop mixture with legume crops, and breeding appropriate plant type of rice for the enhancement of competitive ability would be required for the success of no-tillage system.

• Journal of Biosystems Engineering
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• v.17 no.3
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• pp.237-246
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• 1992

This study was conducted to investigate experimentally the effect of track tension on the tractive performance of rice combine. The experiment was carried out at the two in-door soil bins with soil types of loam and sandy loam. The initial track tension was varied by three different values of 0.71, 1.75 and 3.84kN at three different forward velocity settings of 0.17, 0.32 and 0.45m/s, respectively. The data acquisition system was designed and used for the measurement of pull, driving axle torque and its velocity under the test conditions to calculate the tractive efficiency. Results of the study were summarized as follows : 1) The effect of the initial track tension on the tractive efficiency was found being significantly dependent on soil types but not on forward velocities. Therefore, the benifit of adjusting the initial track tension may be obtained when the types of soils on which combines operate are changed. 2) In loam, tractive efficiency decreased with increase in track tension. However, it increased in sandy loam until it reached to a peak value and then decreased with increase in track tension. 3) The maximum tractive efficiency of the tested combine was obtained with an initial track tension of about 1.75kN on sandy loam, and below that on loam at about 5% slippage without being noticeably influenced by the forward velocity.

• Journal of Biosystems Engineering
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• v.31 no.3 s.116
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• pp.194-202
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• 2006

Using a multi-variable linear regression technique and SUR(seemingly unrelated regression) model, the demand functions of tractor, combine and rice transplanter were estimated. The demand was regarded as an annual supply of each machine and modeled as a function of 11 independent variables which reflect the actual farmer's income, actual prices of farm machines, previous supply, previous stock, actual amount of available subsidy, actual amount of available loan, arable land, import of farm machines and rice price. The actual amount of available loan affects most significantly the demand functions. The actual farmer's income, actual farmer's asset, loan coverage, and rice price affect the demand positively while prices of farm machines and import negatively. The annual demands of tractor, combine and rice transplanter estimated using the demand functions were also presented over the next 4 years.

• Journal of Biosystems Engineering
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• v.40 no.3
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• pp.159-164
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• 2015

Purpose: Recently, environmental pollution and safety problems in agricultural production have become important issues. Initially, bio-production machines focused on high production efficiency rather than workers' safety and comfort, but this trend slowly has changed as time went on. Methods: This study was carried out to identify sound efficiently and reliably for noise reduction by using a combine cabin model. Ethylene propylene diene monomer (M-class) rubber (EPDM) was applied to improve noise reduction performance from parts connected directly to the front, rear, left side, and bottom side of the cabin. Results: As a result, an average noise reduction of 1.85 dB was achieved in the normal hearing range between 500 Hz to 2 kHz. Conclusions: Reducing the cabin noise levels can reduce a worker's fatigue, improve working environment, and contribute to future low-noise and high-quality cabin environment.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2002.11a
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• pp.163-166
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• 2002

OFDM should be used for the fourth generation communication for high speed communication. Because of high spectral efficiency and high tolerance to fading channel, OFDM is applied to many high speed wire and wirless communication such as DAB(Digital Audio Broudcast), DVB(Digital Video Broadcast), IMT 2000 etc. Inter-modulation, however, is derived from PAR(Peak to Average Power Ratio) of OFDM signals. The paper describes PTS(Partial Transmit Sequence) and SLM(Select Mapping) of an existing methods which can reduce PAR. And then the document introduces the new method that is called "Combine PAR method". The method proposed in this paper is to combine PTS and SLM. As a result of the simulation, Combine PAR method is better than the existing methods.g methods.