• Journal of Biosystems Engineering
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• v.20 no.1
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• pp.22-35
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• 1995

Pepper is the most important horticultural plant in Korean farm. Pepper harvesting has been known to be the most difficult process in pepper cultivation so that demand for mechanization is strong. In a research to develop a pepper harvesting machine performance and capacity of the harvester should be determined based on both economical feasibility and machine design concept. In order to accomplish an economical analysis of the pepper harvester, a mathematical model for comparing manual harvesting cost to machine harvest cost was developed. Validity of the model depends on the data used in the model. Economical information for the model variables was acquired from the result of farm survey on pepper cultivation technique and economics of pepper farmer. Technical information on pepper harvester were also collected through literature review and analyzed. Based on the economical analysis and synthesis of the technical information on pepper harvesters, its performance and capacity were determined. The operating performances of the harvester such as cutting, conveying, flipping, pepper removing and post-processing (sorting) were determined. Daisy capacity of the machine was determined to be 0.41 ha. A pepper harvester with the suggested capacity was economically feasible if the price of pepper harvester, pepper recovery ratio and service life of harvester were about 6 million won, 80%, and 4 years, respectively.

• Journal of the Korean Society of International Agriculture
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• v.30 no.4
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• pp.370-375
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• 2018

In order to promote the mechanized cultivation of perilla for seed, which has been increasing in cultivation area and production recently as demand increases according to the health-functional effects, we carried out this experiment to determine the optimum sowing time of perilla to minimize the seed loss at harvest and increase the yield. We used two different types of perilla varieties, 'Sodam(small-branch)' and 'Deulsaem(multi-branch)', and the sowing time was June 15, June 30, July 15 and August 1. As the sowing time is late, days of growth from sowing to flowering were shortened, and they were shortened from 14, 26 and 31~32 days on June 30, July 15 and August 1 as compared with June 15, respectively. And, the stem length and culm diameter were shortened or tapered and the number of nodes tended to decrease. The number of effective branch was 82%, 61% and 56% on June 30, July 15 and August 1 as compared with June 15, respectively. Accordingly, it seems to make against in securing the yield from July 15. And, the lowest cluster height was generally shorter as the sowing time is late, and the height was below 15cm on July 15 and August 1. It seems that this may work against the machine harvest. There was a high degree of significance between the sowing time and the yield. Although, the total yield was not statistically significant among June 15, June 30 and July 15, the ratio of shattering seed at harvest was in order of July 15, August 1(30.3%)> June 15(15.3%)> June 30(13.5%). Therefore, the net yield except for shattered seed was higher in order of June 30${\geq}$ June 15> July 15> August 1. This tendency was characteristic regardless of variety and sowing method. And, the protein content in perilla seed increased as the sowing time was delayed, and the content was the highest on August 1. The content of crude fat was relatively high on June 15 and July 15 in 'Sodam', and June 30 and July 15 in 'Deulsaem', respectively. And, the content of linolenic acid was found to be the highest on August 1. As a result, the optimal sowing time for machine harvest of perilla for seed is about June 30. At this time, it is determined that the sowing time is the most suitable to be advantageous in increasing the yield of perilla seed, while minimizing the seed loss due to the shattering at harvest.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.38 no.4
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• pp.324-329
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• 1993

Effects of leaf and pod removal on changes in leaf and seed number, and leaf, seed, pod and stem dry weight of soybean [Glycine max (L,) Merr.] cultivar ‘Hwangkeumkong’ were measured at the research farm of Korea University in 1992. The upper 40% and lower 60% of leaves and pods were subjected to treatments at the growth stage of beginning pod(R3). Leaf number and dry weight of lower part were increased by upper leaf-lower pod removal, but seed number and dry weight were decreased. Upper leaf-lower pod removal increased lower stem dry weight and decreased upper pod dry weight. Leaf-seed ratio of the upper leaf-lower pod removal was the highest with 3.54 and harvest index was the lowest with 27% among the treatments. Lower leaf-upper pod removal showed that more assimilates from upper leaves were translocated to lower seeds than from lower leaves to upper seeds in upper leaf-lower pod removal treatment.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.50 no.5
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• pp.309-318
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• 2005

Higher level of KCl application stimulated both leaf area index and leaf area duration in all cassava varieties, while the leaf and tuber number of the bitter varieties (high cyanide-level varieties) decreased in proportion to the level of KCl application. The root/shoot (R/S) ratio and harvest index (HI) were negatively related with the level of KCl application in all cassava varieties. The bitter varieties obtained the lowest R/S ratio at the level of 100 - 150 kg KCl $ha^{-1}$, while the sweet varieties (low cyanide-level varieties) acquired the highest values at the level of 50 - 150 kg KCl $ha^{-1}$. Also, the sweet varieties showed the lowest HI at the level of 250 kg KCl $ha^{-1}$, but the bitter varieties at the level of 150 kg KCl $ha^{-1}$. At 6 - 8 months after planting, the sweet varieties tended to obtain higher starch content of roots (tubers) at the level of 50 - 150 kg KCl $ha^{-1}$, while the bitter varieties at the level of 150 - 250 kg KCl $ha^{-1}$. Relatively lower level of 50 - 150 kg KCl $ha^{-1}$ was more appropriate for decreasing hydrocyanic acid (HCN) content of roots (tubers) in the sweet varieties at the harvest time, and the level of 250 kg KCl $ha^{-1}$ was adequate to decrease not only HCN content of leaves but also that of roots (tubers) in the bitter varieties during the growing period. To obtain higher yield and starch content of tubers, and lower HCN content of roots (tubers), it was recommended that the sweet varieties are applied with the level of 50 - 100 kg KCl $ha^{-1}$ and the bitter varieties with the level of 150 - 200 kg KCl $ha^{-1}$, respectively, in Latosol soils of Bogor areas, West Java.

• Korean Journal of Soil Science and Fertilizer
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• v.24 no.1
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• pp.50-54
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• 1991

This study was conducted to evaluate the effect of five newly developed slow-release compound fertilizer varying urea/formaldehyde mole ratios on chinese cabbage against the checked plot of straight fertilizer. The chinese cabbage was obtained the highest yield in the product V which was 1.0 mole ratio of urea/formaldehyde adding with 6.7% urea resin, however, it was lowest in the product VII which the lowest mole ratio of urea/formaldehyde and the highest amount of the resin added. The appropriate product with one basal application for chinese cabbage should be one with 76.1 % of T-N dissolution in water after 24hrs and 71.7 % of T-N dissolution in soil 100 days after treatment. The total nitrogen content of the harvest plant in the product plot was lower compared to the checked plot of N P K and the available soil phosphrous after harvest was higher than that of the checked.

• Journal of the Korean Society of Tobacco Science
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• v.16 no.2
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• pp.144-151
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• 1994

Using a flue-cured tobacco variety, BU 109, effect of growth regulators(Fatty Alcohol and C-MH) on the change of invertase activity and sugar metabolites were investigated. Invertase activity in untreated leaf tissue was decreased along with maturation of leaf, However, a momentary increase of the activity was observed in leaves by the dual treatment of fatty alcohol and C-MH regardless of leaf position while sole C-MH treatment resulted in activity increase by 14 days after the treatment. Similar tendency was observed in stalk. Sugar content in leaf was increased immediately after the treatment but no significant increase at large resulted until 14 days after treatment. After harvest, reducing sugar was increased by the growth regulators. Nevertheless, in case of dual treatment, the total sugar content was not different with that of untreated control. R/T ratio was gradually increased after topping stage and reached maximum at 14 days after treatment of growth regulators. It decreased a little after harvest but the RR ratio was relatively higher due to increase of reducing sugar resulted by the treatment of the chemicals. Upon treatment of growth regulators, reducing sugar content was increased in lugs and leaves compared to untreated control and the content of sugar metabolites was increased by the use of the chemicals either at lower or higher than recommended dose. Key words : MH, FA, invertase activity, total sugar, reducing sugar

• Food Science and Preservation
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• v.11 no.4
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• pp.491-495
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• 2004

Consumers were tend to purchase more natural sweeting materials then atificial sweeting materials because of safety and the consumed amount of natural sweeting material was increased sharply with consumers concern to health. The proper harvest time with changes of sweeting material contents was investigated in the purpose of cultivation and utilization on functional foodstuff, Soluble solid content and extraction yield were increased with growth priod, but pH was decreased. Color value, transmittance and browning color showed little. L, a, b values was changed a little. Stevioside ratio($68.97\%$) in sweetness components was decreased to $61.09\%$. Rebaudioside A ratio was increased from $20.83\%\;to\;27.52\%$ stevioside contents was maximized to $12.80\%$ of August. The highest sweetening potencies of stevia leaves was 2530times to sugar. The stevia leaves harvested at May showed the best deliciousness.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.14 no.1
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• pp.1-19
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• 2020

In an underlay cognitive simultaneous wireless information and power transfer (SWIPT) network, communication from secondary user (SU) to secondary destination (SD) is accomplished with decode-and-forward (DF) relays. Multiple energy-constrained relays are assumed to harvest energy from SU via power splitting (PS) protocol and complete SU secure information transmission with beamforming. Hence, physical layer security (PLS) is investigated in cognitive SWIPT network. In order to interfere with eavesdropper and improve relay's energy efficiency, a destination-assisted jamming scheme is proposed. Namely, SD transmits artificial noise (AN) to interfere with eavesdropping, while jamming signal can also provide harvested energy to relays. Beamforming vector and power splitting ratio are jointly optimized with the objective of SU secrecy capacity maximization. We solve this non-convex optimization problem via a general two-stage procedure. Firstly, we obtain the optimal beamforming vector through semi-definite relaxation (SDR) method with a fixed power splitting ratio. Secondly, the best power splitting ratio can be obtained by one-dimensional search. We provide simulation results to verify the proposed solution. Simulation results show that the scheme achieves the maximum SD secrecy rate with appropriate selection of power splitting ratio, and the proposed scheme guarantees security in cognitive SWIPT networks.

• Journal of Ginseng Research
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• v.5 no.2
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• pp.85-91
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• 1981

Ginseng seeds were gathered from 3,4,5 and 6 years of age and were classified into four qroups (below 4mm, 4∼5mm, 5∼6mm and above 6mm in across sieve). They were sown in seedling bed and some characters were investigated in each qroup of seed size. 1. The distribution of seed size of below 4mm, 4-5mm, 5-6mm and 6mm were 23.7%, 60.8%, 12.4% and 4.5%, respectively. 2. The ratio of seed coat dehiscence was not affected by seed size but emergence ratio and emerging vigor were superior in large seed. 3. The large seed showed superiority in stem length, stem diameter, leat and also in root length, root diameter and root weight. but diseased root was not affected by seed size. The effect of age(seed harvest) was not significant on all those characters.

• Journal of Korean Society on Water Environment
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• v.31 no.3
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• pp.328-333
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• 2015

In this study, Mg-Sericite was used as a flocculant to harvest freshwater microalgae, Chlorella. vulgaris. Mg-Sericite separated successfully >95% of the C. vulgaris at the following optimal parameters: Mg/Si mol ratio 1.25 to 1.50, mixing time of 20 min and settling time of 20 min. The harvesting efficiency was pH dependent. The highest harvesting efficiency ($99{\pm}0.3%$) was obtained at Mg/Si mol ratio 1.5 and pH 9 to 11. These results indicated that a biopolymer, Mg-Sericite, can be a promising flocculant due to its high efficiency, low dose requirements, short mixing and settling times. This harvesting method is helpful to lower the production cost of algae for biodiesel.