• Proceedings of the Korean Society for Agricultural Machinery Conference
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• 1993.10a
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• pp.1088-1094
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• 1993

One of the important restraint conditions for determination of rotary tiller parameters is whether the outside of front cutting surface on blade in rotary tiller pushes untilled soil in operation. By theoretical analysis and graphic verification on computer, no sil-push conditions is put forward and formula for calculating the position angle of its bent line derived, as is convenient for selection of rotary tiller parameters and design and drawing of its blade.

• Korean Journal of Agricultural Science
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• v.50 no.3
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• pp.427-435
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• 2023

This study was conducted to evaluate the spraying performance according to the flight conditions of agricultural drones for the development of a variable control system. The analyzed flight conditions comprised six factors: spraying direction, flight speed, altitude, wind speed, wind direction, and rotor rotational speed. The ratio of the area sprayed on the water-sensitive paper was used as the coverage, and the distribution and amount of the coverage were evaluated. The coverage distribution based on the distance from the drone was used to evaluate a spray pattern, and the distribution was expressed as a Gaussian function approximation. In addition, the probability distribution based on coverage was expressed as the cumulative probability via Gamma function approximation to analyze the spraying efficiency in the target area. The results showed that the averaged coverage decreased significantly as the flight speed and wind speed increased, and the wind direction changed the spray pattern without a coverage decrease. This study contributes to the development of a control technique for the precision control system of agricultural drones.

• Mycobiology
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• v.37 no.4
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• pp.313-316
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• 2009

To determine the optimal medium conditions for the detection of the cellulolytic activity in Ganoderma lucidum, we varied three media conditions: dye reagent, pH, and temperature. First, we evaluated the use of four dyes, Congo Red, Phenol Red, Remazol Brilliant Blue, and Trypan Blue. To observe the effect of pH on the chromogenic reaction, we also made and tested various media spanning acidic and alkaline pHs, ranging from 4.5 to 8.0. Furthermore, in order to research the effect of temperature on the clear zone and the fungus growing zone, we tested temperatures ranging from 15 to $35{^{\circ}C}$. On the whole, the best protocol called for Ganoderma lucidum transfer onto media containing Congo red with pH adjusted to 7.0, followed by incubation at $25{^{\circ}C}$ for 5 days. Our results will be useful to researchers who aim to study extracellular enzyme activity in Ganoderma lucidum.

• Proceedings of the Korean Society for Agricultural Machinery Conference
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• 1993.10a
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• pp.984-993
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• 1993

land application of sewage sludge requires careful monitoring because of its potential for contamination of surface water and groundwater. A rainfall simulator was used to investigated the effects of freshly applied sludge on runoff of sediment and nutrients from agricultural crop lands. Rain was applied to 16 experimental field plots. A three run sequence was used to simulate different initial moisture conditions. Runoff, sediment and nutrient losses were monitored at the base of each plot during the simulated rainfall events. Sludge was surface applied and incorporated at conventionally -tilled plots and surface applied at no-till plots, at rates of 0, 75, 150 kg-N/ha. No-till practices greatly reduced runoff, sediment , and nutrient losses form the sludge treated plots, relative to the conventional tillage practices. Incorporation of the sludge was effective in reducing nutrient yields at the conventionally-tilled plots. This effect was more pronounced during the third rain torm, with wet initial conditions. Peak loadings of nutrients appeared during the rainstorm with wet initial conditions.

• Journal of the Korean Society of Food Culture
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• v.29 no.6
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• pp.577-584
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• 2014

The purpose of this study was to compare understanding of school foodservice management and environmentally friendly agricultural products between urban and rural elementary school children's mothers. Subjects were 400 elementary school parentsliving in Jeonnam. The results are summarized as follows. School foodservice program helped to solve unbalanced diets, develop minds and bodies, and improve eating habits. Mothers showed a higher degree of satisfaction for school foodservice containing environmentally friendly agricultural products. The primary reason for favoring environmentally friendly agricultural products was improvement of health and securing safe foods. The most important parameter of school foodservice management was sanitary control of food materials>sanitary control of foods>sanitary conditions of place for meals>sanitary conditions of cooker>sanitary conditions of tableware. In conclusion, school foodservice should be financially responsible to make policies effective.

• Food Science and Preservation
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• v.30 no.6
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• pp.905-917
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• 2023

The optimal fermentation conditions for producing fermented black soybeans rich in sulfur-containing amino acids were investigated. Response surface methodology monitored fermentation conditions. A central composite design examined the effect of independent variables: enzyme concentration (X₁) and fermentation time (X₂) on yield and methionine content. Both factors significantly influenced these dependent variables. Enzyme concentration more profoundly affected amino nitrogen content than fermentation time. β-Glucan content and cystine level were primarily affected by fermentation time. We elicited each variable's regression formula and identified optimal fermentation conditions for functional compounds. The predicted optimum conditions were an enzyme concentration of 0.28-0.32% and a fermentation time of 58.0-62.0 min. Under these optimal conditions, each black soybean variety's sulfur amino acid content ranged from 818.62 to 922.62 mg/100 g, demonstrating significant variety differences.

• Journal of Apiculture
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• v.33 no.4
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• pp.239-250
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• 2018

We investigated the pollination activity of honeybees (Apis mellifera L.) in terms of different climatic conditions in the greenhouse cultivation of watermelons (Citrullus lanatus L.) during winter. The aim of the study was to search a climatic condition which effectively can be use honeybees as pollinators during the flowering season of watermelons in winter or early spring. The average climatic conditions inside the greenhouse during the bee activity time (BAT)-between 10:00 and 16:00 in mid-Februarywere a temperature of $30.4^{\circ}C$, relative humidity of 53.7%, illuminance level of 22,728.4lx, and UV level of $0.233mW/cm^2$. Bee traffic and foraging activity were at their greatest at 10:00 and tended to decrease with time. Male watermelon flowers typically dehisced between 10:00 and 12:00. Climatic conditions were significantly correlated with bee activities, including bee traffic and foraging activity. Bee activities were positively correlated with temperature, illuminance level, and UV level but negatively correlated with relative humidity. Temperature had the greatest effect on honeybee behavior. Among the foraging honeybees, the number of high-flying bees that did not pollinate flowers showed a strong positive correlation with temperature, and the number of bees landing on the flowers showed a positive correlation with the UV level. The temperature range inside greenhouses at which the pollination activities of honeybees can be maintained efficiently during winter watermelon pollination was found to be $21{\sim}25^{\circ}C$.

• Mycobiology
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• v.38 no.3
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• pp.195-202
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• 2010

Coriolus versicolor, is one of the most popular medicinal mushrooms due its various biologically active components. This study was conducted to obtain basic information regarding the mycelial culture conditions of C. versicolor. Based on the culture, and MCM media were suitable for the mycelial growth of the mushroom. The optimum carbon and nitrogen sources were dextrin and yeast extract, respectively, and the optimum C/N ratio was 10 to 2 when 2% glucose was used. Other minor components required for optimal growth included thiamine-HCl and biotin as vitamins, succinic acid, lactic acid and citric acid as organic acids, as well as $MgSO_4{\cdot}7H_2O$ as mineral salts.

• Journal of Biosystems Engineering
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• v.31 no.5 s.118
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• pp.443-448
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• 2006

For development of an on-line monitoring unit of fermentation process, an auto dilution unit based on traditional chemical and biological analytical method was developed and the performance was evaluated. The dilution unit was constructed with two syringe pumps and flow direction change valves and fully automated. Total delivery volume of two pumps using distilled water was measured to confirm the operating stability And diluted concentrations of three substrate solutions (glucose, lactic acid, ethanol) were compared with a standard method with a high performance liquid chromatograph (glucose, lactic acid) and gas chromatograph (ethanol). Relative error values of total delivery volume of the pumps were below 3% and standard deviation values were 0.003 (n=5). Relative error values of diluted concentration of the dilution unit measurements were below 2% with 1/10 of dilution ratio and 70, $80{\mu}{\ell}$ of sample volume conditions for glucose and lactic acid, 1/30 of dilution ratio and $70{\mu}{\ell}$ of sample volume conditions for ethanol, respectively. In case of the ethanol, cause of the evaporative characteristics, the relative error values showed over 5% whole experimental conditions.

• The Plant Pathology Journal
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• v.17 no.6
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• pp.373.3-373
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• 2001