• Journal of Biosystems Engineering
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• v.36 no.5
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• pp.361-368
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• 2011

The amount of export of paprika has been increased rapidly in recent years. Therefore, its cultivation area has greatly increased in Korea according to current consumer's attraction. Moreover, it becomes one of the major exporting products while it recorded 53 million dollars, in 2009 resulting in 40% of the total vegetables export. Most of the products are exported to Japan, but it is necessary to prolong the quality preservation periods to export paprika to nations like U.S.A. or EU. However, to encourage an export to many countries, washing and disinfection became more important to deal with longer transportation and medical inspection. The non-chemical use is very important due to stronger regulation of safety to agricultural production. Accordingly, this study was performed to determine the optimum conditions and develop a prototype washing machine, hot water washing of paprika. The results were as follows : The working performance of the prototype was 938 kg/hr, and which was 1.5 times higher than the conventional air gun type washing machine. The operation cost of prototype was 30 won/kg, and 56% of the cost was reduced when compared with air gun type washing machine.

• Environmental and Resource Economics Review
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• v.9 no.5
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• pp.853-876
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• 2000

The purpose of this paper is to come up with the measures for sustainable development of the agricultural sector in store for the strengthened U.N. Framework Convention on Climate Change. We analyze the spillover effects of Methane and Nitrous Oxides taxes (carbon tax) on the Korean agricultural sector. Unlike the other sectors, the agricultural sector has a unique characteristic generating greenhouse gas in the process of production itself even without consuming much fossil fuel. In order to estimate the impacts of those taxes, non-linear optimization method has been used with various assumed scenarios. The production effect, income and' price effect, and greenhouse gas emission reduction effect in the agricultural sector have been estimated through this method. The empirical results show that the paddy sector has a bigger tax effect than the livestock sector. In the paddy sector, the carbon tax has more impacts in the suburban areas than in the rural areas, while the swine farming section in the livestock sector has a conspicuous income effect in the midst of low greenhouse gas emission effect. These results allude us to apply graded tax rates to the crop, the livestock, and the region of different kind. Even if the agricultural sector has a less tax effect when compared with other industrial sectors, an environmental tax might be an effective measure to prevent global warming.

• Current Research on Agriculture and Life Sciences
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• v.30 no.1
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• pp.41-50
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• 2012

As a part of abating formaldehyde emission of urea-formaldehyde resin, this study was conducted to investigate the rmalcure kinetics of both neat and modified urea-formaldehyde resins using differential scanning calorimetry. Neat urea-formaldehyde resins with three different formaldehyde/urea mol ratios (1.4, 1.2 and 1.0) were modified by adding three different additives (sodium bisulfite, sodium hydrosulfite and acrylamide) at two different levels (1 and 3wt%). An isoconversional method at four different heating rates was employed to characterize thermal cure kinetics of these urea-formaldehyde resins to obtain activation energy ($E{\alpha}$) dependent on the degree of conversion (${\alpha}$). The $E{\alpha}$ values of neat urea-formaldehyde resins (formaldehyde/urea = 1.4 and 1.2) consistently changed as the ${\alpha}$ increased. Neat and modified urea-formaldehyde resins of these two F/U mol ratios did show a decrease of the $E{\alpha}$ at the final stage of the conversion while the $E{\alpha}$ of neat urea-formaldehyde resin (formaldehyde/urea = 1.0) increased as the ${\alpha}$ increased, indicating the presence of incomplete cure. However, the change of the $E{\alpha}$ values of all urea-formaldehyde resins was consistent to that of the Ea values. The isoconversional method indicated that thermal cure kinetics of neat and modified urea-formaldehyde resins showed a strong dependence on the resin viscosity as well as diffusion control reaction at the final stage of the conversion.

• Journal of Biosystems Engineering
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• v.30 no.4 s.111
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• pp.242-248
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• 2005

There was no useful milling standard to produce high quality milled rice efficiently and adequately in Rice Processing Complex. Therefore, the whiteness of milled rice produced Rice Processing Complexes were different according to Rice Processing Complexes and milling periods at the same Rice Processing Complex. This research was carried out to contribute the production and distribution of high quality milled rice through determination of whiteness condition of milled rice as a milling stndard based on degree of bran removal using New $May-Gr\ddot{u}wald$ reagent dyeing method and taste of cooked rice. The optimum whiteness value of milled rice for efficient milling in Rice Processing Complex was found to be from 40 to 41, while the degree of milling was from $8.9\%\;to\;9.2\%.$ At this whiteness condition, the first derivative of whiteness value according to degree of milling was higher than the average value from brown rice to well milled rice, and the broken kernel ratio was from $3.0\%\;to\;3.4\%.$ This whiteness condition ($40\~41$) could be considered as a milling condition in Rice Processing Complex.

• 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.39 no.3
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• pp.166-173
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• 2014

Purpose: In this study, we focused on the image processing method to determine the external quality of Fuji apples by identifying surface defects such as scabs and bruises. Method: A CCD camera was used to capture filter images with 24 different wavelengths ranging between 530 nm and 1050 nm. Image subtraction and division operations were performed to distinguish the defect area from the normal areas including calyx, stem, and glaring on the apple surface image. All threshold values of the image were examined to reveal the defect area of pretreated filter images. Results: The developed operation methods were [image (720 nm) - image (900 nm)]/image (700 nm) for bruise detection and [image (740 nm) - image (900 nm)]/image (590 nm) for scab detection, which revealed 81% and 90% recognition ratios, respectively. Conclusions: Our results showed several optimal wavelengths and image processing methods to detect Fuji apple surface defects such as bruises and scabs.

• Journal of Biosystems Engineering
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• v.31 no.3 s.116
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• pp.139-145
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• 2006

A previous study showed that the handle vibration of a walking type cultivator can be reduced by adding a mass to the handle. This study was conducted to determine the optimum magnitude and location of the mass to be added for the same cultivator. The possible locations of added mass were determined by investigating nodal points of the handle vibration by an ODS (operational deflection shapes) test at an engine frequency of 52 Hz. The optimum location was then determined as one that moved the nodal points to the hand grip of the handle bar. To determine the optimum magnitude of the mass, the possible locations were added by a mass from 0.2 to 2.0 kg in an increment of 0.2 kg. The optimum magnitude was then determined as a mass which minimized the vibration level at the hand grip. For the case of this study, the z-axis vibration at the hand grip was reduced from $2.67m/s^2\;to\;0.88m/s^2$ resulting in a reduction of 67% and the total vibration from $4.09m/s^2\;to\;3.27m/s^2$ resulting in a 20% reduction by adding an optimum mass to the optimum location.

• Journal of Biosystems Engineering
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• v.18 no.1
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• pp.15-20
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• 1993

Wearness has been a major failure criterion in Korean-made rotary blade. However, few studies have been conducted to improve it. In this study, the fundamental data obtained from the measurement of wearness and failure of rotary blade were analyzed to provide a guideline for the design of rotary blades. For the straight part(about 20-23 em from bolt hole) from the bolt hole to bending point of rotary blade, modifications were proposed for improvements, however, for the portion from bending point to tip was made no design recommendations because the failure behavior of that portion was difficult to analyze with the experimental data. The results are summarized as follows. 1. The current V-shape section has to be moved about 5 em toward the bending point of rotary blade. 2. The section modulus at the portion about 5-7 em distant from bolt hole has to be increased about 15-20 %. 3. The V-shape section has to be changed into U-shape to reduce the on account of recieving initial stress in blades. 4. The radius of curvature of the neck(the portion about 5-7 cm apart from bolt hole) has to be made larger to decrease the stress concentration.

• Journal of Biosystems Engineering
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• v.26 no.4
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• pp.337-354
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• 2001

This study was conducted in order to develop a Chinese cabbage harvester attachable to tractors. For designing Chinese cabbage harvester in which laboratory and field tests were conducted with to determine feasible values design factors. To adopt the various sizer of C-cabbages, U-type soft rubber band was attached to the chain conveyor with an angle. Required torque of the conveyor axle was about 206-210kgf$.$cm. And the required peripheral speed of the disk cutter was 6.54m/s or more to have a clean session in root cutting. Three different harvest method were tested. The best harvesting method with minimum pulling force and damage was disk cutting flying just above the soil surface were the cut chinese cabbages are transferring to the holding conveyor attached soft rubber lug in prompt. Theoretical speed ratio of the tractor travel and feed of a chain conveyor was 1:1.2 with the attaching angle of 30 degree and 1:1.1 with the angle of 20 degree. Actual field experiment showed the speed ratio of 1:1.5 was the best because of the slip effect.

• Journal of Biosystems Engineering
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• v.13 no.2
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• pp.1-8
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• 1988

A scale model of power tiller-trailer system with the same kinematic characteristics was constructed one eighth of the actual size to validate the effectiveness of mathematical model of motion. The parameters for the scale model of power tiller-trailer system were measured by a series of laboratory experiments. Validation tests for the: scale model was conducted under several ground and operating conditions. The tests were performed on artificial ground surfaces with several kind, of slope and obstacle. The travel path of the scale model was photographed successively in three directions. The travel paths obtained from both the film analysis and the simulation model appeared to be consistent with each other. It was concluded that the simulation model could be used to predict the motion of actual power tiller-trailer system if the parameters for actual power tiller and trailer are provided.