• Korean Journal of Agricultural Science
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• v.23 no.2
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• pp.323-329
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• 1996

This paper is aims at studying the economics of scale of sweet potato cultivation. Sweet potato is one of the decreasing crop. Its cultivated areas has been decreasing more rapidly than soybean or corn. In this paper 23 farmers were surveyed, including 8 families with less than 1 ha, 7 families with 1-5 ha, and 8 families with more than 5 ha. The results are as follows; First, sweet potato cultivation is good for specialization, considering the high income per acre. Second, there is no good evidence explaining for the economy of scale of sweet potato cultivation, but there is an evidence for the profit of specialization. Large scale farmers have more incomes per acre, lather than more production or less management costs, by means of good sales methods. Third, mechanization of sweet potato cultivation is one of the key factor for successful large scale sweet potato cultivations.

• International journal of advanced smart convergence
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• v.12 no.4
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• pp.464-469
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• 2023

The government has set the mechanization of paddy agriculture as a national task, aiming to achieve over 70% by 2025. The main objective is to stabilize the farming costs of rural households due to the aging and feminization of rural areas, as well as the shortage of agricultural labor. In response to this, the Korea Rural Economic Institute operates a farm machinery rental business. However, there are challenges in selecting and managing rental machinery, including issues related to labor, costs, verification, and time. Additionally, there is a limit to upgrades, and overseas models are being imported and used for transplanters and rice planters, which do not conform to domestic standards and face maintenance difficulties. In order to solve the difficulties of the agricultural machine rental business, we intend to develop an application that shares domestic and foreign machines purchased and used by individuals at a low cost and use them in gun-level administrative districts.

• Journal of Biosystems Engineering
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• v.20 no.3
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• pp.245-249
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• 1995

In this study power requirements to saw shoots with circular saw were determined by measuring and analyzing the required maximum torque to provide the information for the mechanization of Korean pine cone harvest. Two levels of feed rate of shoots, 10.4mm/s and 20.8mm/s, three levels of sawing speed 5.8㎧, 11.6㎧, and 17.4㎧, and 14 levels of shoot diameter from 7.7 to 18.1mm were used as variables. 1) The maximum torques were significantly affected by all three variables. The average maximum torque, 18.2 N-cm for feed rate of 20.Bmm/s was greater as much as 80% of 10.1 N-cm for feed rate of 10.4mm/s. 2) As the sawing speed was increased from 5.8㎧ to 11.6㎧ and 17.4㎧, the maximum torques were decreased to 14.8N-cm, 8.5N-cm, and 7.IN-cm, respectively when the feed rate was 10.4mm/s. The maximum torque ranged from 4.5 to 19.3N-cm as shoot diameter increased from 7.7 to 18.1mm. The minimum power requirements to saw shoots of 18.1mm with circular saw was 30W for the feed rate of 10.4mm/s. 3) The maximum torques were 28.6N-cm, 14.6N-cm, and 11.4N-cm when sawing speeds were 5.8㎧, 11.6㎧, and 17.4㎧, respectively when the feed rate was 20.8mm/s and these torques were increased as much as 93%, 36%, and 61% of those for the feed rate of 10.4mm/s. The maximum torque increased from 9.7N-cm to 30.7N-cm as shoot diameter increased from 7.7 to 18.1mm. The minimum power requirements to saw shoots of 18.1mm was 54W which was 1.8 times of 30W for the feed rate of 10.4mm/s.

• Proceedings of the Korean Society for Agricultural Machinery Conference
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• 1993.10a
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• pp.734-743
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• 1993

The performances of three same type of vibrating potato diggers were estimated by observing the potato separation and material flow on the bottom plate. Four-bar mechanism were adopted for three diggers and pairs of eccentric cams on both sides of driving shaft were used as driving link of the diggers. Each machine was tested with different amplitudes , frequencies, and travels speeds. Blade performance were observed in three categories : Impossible forward travel , acceptable operation, and unsatisfactory potato digging , but good material flow. Three parameters were used to set marginal values that enable the machines operate for potato digging, and the parameters were compared to select best one. Three parameters are λ, $\rho$, and K.λ is the ratio of vibrating speed to travel speed, $\rho$ is the ratio of blade acceleration to travel speed, and K is the ratio of blade acceleration to gravitational acceleration. K value of 2 or more is suggested to be used as design and evalu tion criterion of the vibrating digger.

• Journal of Biosystems Engineering
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• v.40 no.4
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• pp.320-326
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• 2015

Purpose: Kimbugak is one of Korea's traditional snack foods made of laver. Mechanization of the manufacturing process is necessary to produce kimbugak in large quantities and standardize the products for industrialization. This study was conducted to develop a machine that can simultaneously accomplish the two processes of pasting and garnishing for manufacturing kimbugak, and test its performance. Methods: A pasting and garnishing machine was designed, and its target work efficiency was set at 720 sheets/h. The performance was tested based on the physical characteristics such as work efficiency, pasting uniformity, and garnishing uniformity. Results: With the developed technology, kimbugak could be produced up to a productive rate of 840 sheets/h on a single machine. The pasting uniformity ranged from 91.5% to 96.8%, and a garnishing uniformity of more than 90% could be obtained. Conclusions: It is expected that this approach to developing a machine with the functions of pasting and garnishing can contribute to the mechanization of the manufacturing process to produce Korean traditional foods including kimbugak in large quantities and standardize the products for industrialization.

• Journal of Biosystems Engineering
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• v.31 no.6 s.119
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• pp.500-505
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• 2006

Jujube is one of korean most favorite fruits. Harvesting operations of the jujube farming, however, completely depend on hand labor. Especially, collecting operation requires about three times of hand labor compared with separate operation by impacting or shaking of twigs in the hand-harvesting system of jujube fruits. Consequently, jujube farmers sincerely demand the mechanization of the collecting operation of jujube fruits in the harvesting operation. A new collecting system was designed and constructed five parts-collecting pad, guide ring system, sorting system, frame with driving system, and handle with operation levers, which performed collecting operation of jujube fruits without missing fruits in five part functions, however, an extra future more deliberate study would need how to handle conveniently the collecting pad of the prototype in the narrow space of row of the jujube farm.

• Journal of Biosystems Engineering
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• v.19 no.1
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• pp.17-21
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• 1994

This reasearch was performed to provide the fundamental intonation for the mechanization of Korean pine cone harvest when the shoot shearing method is adopted. Shear force and stress of pine cone shoots were measured and analyzed for this purpose. Samples are selected along their harvesting time and tested in 17 levels of shoot diameter from 10 to 26mm with 1mm increment. 1) Shear force-deformation characteristics showed that shoot reached its rupture point after 2 to 4 of bio-yield points. It was supposed that these multiple bio-yield points were caused by the discrete compression of wood parts which are composed of water, nutrient, resin, etc. 2) Required shear force to shear shoot was proportional to the square of shoot diamter, however, shear force for shoots of early harvesting time(Aug. 31) was proportional to the shoot diameter. Variance of shear force was increased as the harvesting time was delayed. Shear forces were distributed from 468N(Aug. 31, 12mm dia) to 4153N(Aug. 31, 26mm dia) disregarding the sampling date. 3) The average shear stresses by sampling dates were 744,822, and 883N/m2, respectively, and for the earlier shoot samples shear stress was quite smaller than the others. Shear stress was proportional to shoot diameter squared, and the effect of shoot diameter on the shear stress was decreased as harvesting time was delayed.

• Journal of Biosystems Engineering
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• v.22 no.4
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• pp.411-420
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• 1997

The mechanization efficiency using high ability machines such as tractors or combines in a paddy field rice farm is high. Mechanization in harvesting fruits and vegetables is difficult, because they are easy to be damaged. Therefore, Advanced techniques for careful handling fruits and vegetables are necessary in automation and robotization. An apple harvesting robot must have a recognition device to detect the positioning of fruit, manipulators which function like human arms, and hand to take off the fruit. This study is related to the development of a rotatic hand as the first stage in developing the apple harvesting robot. The results are summarized as follows. 1. It was found that a hand that was eccentric in rotatory motion, was better than a hand of semicircular up-and-down motion in harvesting efficiency. 2. The hand was developed to control changes in grasp forces by using tape-type switch sensor which was attatched to fingers' inside. 3. Initial finger positioning was set up to control accurate harvesting by using a tow step fingering position. 4. This study showed the possibility of apple harvesting using the developed robot hand.

• Korean Journal of Agricultural Science
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• v.22 no.1
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• pp.110-126
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• 1995

Korean economy has been developed successfully in the course of implementing the five year economic development plans since 1962. The gap of incomes and quality of life between rural and urban area has been widened and it made rural farm laborers drain to urban areas. Therefore the prevailing situation of labor shortage and wage hike in rural area has made farm management deteriorate in recent years. Under the internal and international unfavorable economic conditions, marginal farm land of 66.5 thousand ha has been idled as of end of 1993. The total area outside agricultural development zone with bad farming conditions including irrigation and drainage, and land consolidation for mechanization were estimated at 360.4thousand ha equivalent to 17.5% of the total farm land area in Korea. Considering the topographical conditions of marginal lands, the effective use of marginal lands should be studied from the view point of public interest rather than from the view point of individual economic conditions. Considering the present agricultural economic settings, such as price decrease, unfavourable benefits of farm products, labour shrotage, free trade of farm products and poor physical condition of marginal lands, the institutional and realistical measures for the effective utilization of idle and marginal land should be studied as soon as possible. Detail land use pattern should be surveyed in the areas outside agricultural development zone and have to be classified as orchard farms, grass land, fish culture farms, lawn and ornamental tree farm, sight seeing and leisure farms for urban peoples, special crops production farms and common farms to be developed for farm mechanization. According to the surveyed results, the expected utilization patterns of the idle and marginal lands could be considerd as village common use, farm land base development, leisure farm development, mutual complementary utilization between urban and rural areas, G't purchase and management, credit supply and new extension services, improvement of cropping patterns and sight seeing and leisure farm patterns. For the successful and reasonable management of the marginal lands, the actions such as institutional improvement, prohibition of idle marginal land, enforcement of activities of farm management committee members and land banking system of RDC including development and utilization systems should be included.

• Agricultural and Biosystems Engineering
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• v.3 no.1
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• pp.29-34
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• 2002

Two charging methods of electrostatic nozzle, i.e. induction and ionized field corona charging, were designed and evaluated for orchard sprayer application. An artificial (metallic) target was constructed and used in this experiment. The charge-to-mass ratio for the induction electrode was measured by using the Faraday cage. Two conventional pressure-swirl nozzles have been employed with different orifice diameters under the same experimental operating conditions. A commercial pressure-swirl nozzle with orifice diameter of 1.0 was used for the conventional spray. The diameter of the electrostatic was 0.59 mm. The experiment was carried out for individual nozzle sprays at $0^{\circ}$, $20^{\circ}$ and $50^{\circ}$ oriented angles and three nozzles, sprayed simultaneously at a distance of 1.0 and 2.0 m from the nozzle tip to the target. The nozzles were mounted on a carriage with constant speed of 1.26 km/h with a blower attached. The weighing method was employed to evaluate for the spray deposition, ground loss and estimated drift. The results show more promising for the induction charging method, especially at $20^{\circ}$oriented angle at a distance of 1.0 m from the target for a single nozzle and when all three nozzles were operated simultaneously for spray deposition. The results of the induction charging method show promising with the developed electrostatic technique.