• Proceedings of the Korean Society of Crop Science Conference
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• 2017.06a
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• pp.73-73
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• 2017

To set an optimal harvest time of main 7 whole crop silage rice cultivars, Nokyang(Ny), Mogwoo(Mw), Mogyang(My), Jungmo1029(Jm1029), Jungmo1038(Jm1038), Nokwoo(Nw) and Yeongwoo(Yw), based on feed value, we analyzed their feed values such as percent crude protein(CP), crude fat(CF), crude ash(CA), neutral detergent fiber(NDF), acid detergent fiber(ADF) and lignin. It was evaluated every 10 days from heading to 40 days after heading(DAH). Total digestible nutrient(TDN) and relative feed value(RFV) was also calculated from ADF and NDF. As results, CP was generally in decline as increasing DAH in Ny, My, Jm1029, Jm1038 and Yw and decreased to 20 DAH in Mw, decreased after increasing to 30 days in Nw. The CP content of Ny was relatively the highest ranged from 5.3% to 10.1% and Mw the lowest 4.5% to 5.2%, compared to others. CF content tend to decrease as DAH increase in Ny, My and Nw and decreased after increasing to 30 days Jm1029, increased after decreasing to 20 days Jm1038 but was not shown distinct trend of increase or decrease in Mw. Especially, that of Yw's CF gradually increased as harvest time late but relative content the lowest from 1.46% to 2.29% among 7 cultivars. The CA content of Ny, My, Jm1029 and Jm1038 approximately decreased as DAH increased and that of Mw was similar to others after heading, Nw decreased after 10 days and Yw increased after flowering. In all 7 cultivars, NDF and ADF had a tendency to decrease as days accumulated, in particular, Yw was the lowest on 30 DAH and so the content of Yw's TDN the highest(71.5%), while the lowest(67.2%) in Nw. For lignin, particularly, Mw tend to be in decline as DAH increase and was the lowest ranged from 1.34% to 1.87%. ADF analyses allows for the evaluation of in vivo digestible dry matter(DDM) and energy availability and NDF analyses provides the best indication of dry matter intake(DMI). Ultimately, the two factors can be combined to derive RFV for forage. RFV in general increased as DAH increased in all cultivars and was in order, Yw>My>Ny> Jm1038>Mw>Jm1029>Nw on 30 DAH. Taken together when these results, despite a slight increase of TDN after 30 DAH except Yw, considering forage yield potential, digestibility of grains and gradual decrease of CP and CF, the yellow ripe stage, about 30 DAH, was appropriate to harvest whole crop rice for silage use.

• Korean Journal of Agricultural Science
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• v.43 no.3
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• pp.330-339
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• 2016

The effect of transplanting and harvest timing was evaluated for the production of high quality pigmented rice in the Yeongnam plain area. Rice was transplanted on June $2^{nd}$ and $14^{th}$ and harvested between 35 - 55 days after panicle heading at 5 - day intervals. Three black- and 3 red-pigmented rice cultivars (such as early cultivar : Josengheugchal, Jeogjinju; medium cultivar : Heugseol, Hongjinju; and mid-late cultivar : Sintoheugmi, Geongganghongmi) were studied. Yield components like spikelet number, ripened grain ratio, and 1,000 - grain weight of the black- and red-pigmented rice cultivars were similar for both the June 2 and June 14 transplantings but panicle number per $m^2$ was higher for the June 14 transplanting than for June 2. This contributed to a higher brown rice yield for the June 14 transplanting, by 6 - 19% for black-pigmented rice, and by 10 - 21% for red-pigmented rice than the yield for the June 2 transplanting. Total anthocyanin and polyphenol productions of the pigmented rice were also higher in the June 14 transplanting than that in the June 2 transplanting due to high brown rice yield. Based on the combined pigmented brown rice yield, we concluded that the optimal harvest timing would be 40 - 45 days after panicle heading (DAH) for the black-pigmented rice and 45 - 50 DAH for the red-pigmented rice. This study suggests that optimum transplanting and harvest timings play an important role for production of high quality pigmented rice in the Yeongnam plain area.

• Journal of Environmental Science International
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• v.24 no.11
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• pp.1547-1550
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• 2015

Fuji apple variety introduced in Japan has excellent storage quality and good taste so it is most commonly cultivated in the Korean Peninsula. Accurate prediction of harvest maturity allows farmers to more efficiently manage their farm, such as working time, fruit storage, market shipment and labor distribution so it is very important. This study was carried out to predict the harvest maturity of 'Fuji' apple using DTS (Days Transformed to Standard temperature) model based on the Arrhenius law in the Gunwi province of the South Korea. Input data are daily average temperature and apple harvest maturity. Predicted the harvest maturity of Fuji apple after estimating the optimal parameters by using the Nelder-Mead method. The differences of observed and predicted harvest maturity day are approximately 1 to 4 days and the RMSE is 2.9.

• Journal of Biosystems Engineering
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• v.41 no.1
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• pp.12-20
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• 2016

Purpose: Pepper prices have risen continuously because of a decrease in cultivation area; therefore, mechanical harvesting systems for peppers should be developed to reduce cost, time, and labor during harvest. In this study, a screw type picking head for a self-propelled pepper harvester was developed, and the optimal working conditions were evaluated considering helix types, winding directions of helix, and rotational speeds of the helix. Methods: The screw type was selected for the picking head after analyzing previous studies, and the device consisted of helices and a feed chain mechanism for conveying pepper branches. A double helix and a triple helix were manufactured, and rotational speeds of 200, 300, and 400 rpm were tested. The device was controlled by a variable speed (VS) motor and an inverter. Both the forward and reverse directions were tested for the winding and rotating directions of the helix. An experiment crop (cultivar: Longgreenmat) was cultivated in a plastic greenhouse. The test results were analyzed using the SAS program with ANOVA to examine the relationship between each factor and the performance of the picking head. Results: The results of the double and triple helix tests in the reverse direction showed gross harvest efficiency levels of 60-95%, mechanical damage rates of 8-20%, and net marketable portion rates of 50-80%. The dividing ratio was highest at a rotational speed of 400 rpm. Gross harvest efficiency was influenced by the types of helix and rotational speed. Net marketable portion was influenced by rotational speed but not influenced by the type of helix. Mechanical damage was not influenced by the type of helix or rotational speed. Conclusions: Best gross harvest efficiency was obtained at a rotational speed of 400 rpm; however, operating the device at that speed resulted in vibration, which should be reduced.

• Preventive Nutrition and Food Science
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• v.21 no.2
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• pp.97-103
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• 2016

In our previous study, an early-maturing variety of rice (Oryza sativa L.), Jinbu can have feature with unique green color, various phytochemicals as well as nutritive components by the optimal early harvesting, called Green Rice$^{(R)}$ (GR). The aims of the present field experiments were to evaluate the changes in the weight of 1,000 kernels, yield, and contents of proximate and bioactive compounds in Chuchung, a mid-late maturing variety, during the pre-harvest maturation of rough rice and to research the appropriate harvest time and potent bioactivity of Chuchung GR. The weights of 1,000 kernels of Chuchung GR dramatically increased until 27 days after heading (DAH). The yields of Chuchung GR declined after 27 DAH and significantly declined to 0.0% after 45 DAH. The caloric value and total mineral contents were higher in the GR than in the full ripe stage, the brown rice (BR). In the GR, the contents of bioactive compounds, such as ${\gamma}$-aminobutyric acid, ${\gamma}$-oryzanol, and ${\alpha}$-tocopherol, were much higher (P<0.05) than those in the BR, specifically during 24~27 DAH. Therefore, bioactive Chuchung GR can be produced with a reasonable yield at 24~27 DAH and it could be useful for applications in various nutritive and functional food products.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.12 no.8
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• pp.3542-3566
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• 2018

In this paper, we investigate a buffer-aided wireless powered cooperative communication network (WPCCN), in which the source and relay harvest the energy from a dedicated power beacon via wireless energy transfer, then the source transmits the data to the destination through the relay. Both the source and relay are equipped with an energy buffer to store the harvested energy in the energy transfer stage. In addition, the relay is equipped with a data buffer and can temporarily store the received information. Considering the buffer-aided WPCCN, we propose two buffer-aided relaying protocols, which named as the buffer-aided harvest-then-transmit (HtT) protocol and the buffer-aided joint mode selection and power allocation (JMSPA) protocol, respectively. For the buffer-aided HtT protocol, the time-averaged achievable rate is obtained in closed form. For the buffer-aided JMSPA protocol, the optimal adaptive mode selection scheme and power allocation scheme, which jointly maximize the time-averaged throughput of system, are obtained by employing the Lyapunov optimization theory. Furthermore, we drive the theoretical bounds on the time-averaged achievable rate and time-averaged delay, then present the throughput-delay tradeoff achieved by the joint JMSPA protocol. Simulation results validate the throughput performance gain of the proposed buffer-aided relaying protocols and verify the theoretical analysis.

• 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.

• Journal of the Korean Society of Food Science and Nutrition
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• v.35 no.9
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• pp.1146-1150
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• 2006

In the present study, the Lycium chinensis Miller was harvested at intervals of one month in order to distinguish outstanding species and to determine optimal harvest time. From these harvests, extracts were prepared from ethanol. The total usable sugar, betaine, and phenolic acid contents as well as electron donating ability and SOD liked activity of the extracts were then measured. While sugar content of the Lycium chinensis Miller showed no significant difference among the various species examined, usable sugar content of the crop harvested in November was higher than that of the crop harvested in August. The Lycium chinensis Miller was picked in August, September, October, and November and analyzed for betaine content. According to this analysis, betaine content was higher in the crop harvested in November than in that harvested in August. In particular, considerable difference in betaine content per species or harvest time was exhibited. The SOD-liked activity in all of the Lycium chinensis Miller extracts showed an alleviation effect of at least 90%. In addition, there was no significant difference according to either species or harvest time. On the other hand, SOD liked activity was higher in November than in August.

• Environmental and Resource Economics Review
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• v.29 no.3
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• pp.363-388
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• 2020

The purposes of this study are to not only estimate optimal harvests and efforts using the surplus production methods for Spanish mackerel caught by multiple fishing gears, but provide dynamic optimal fisheries management for these gears using the current value Hamiltonian method. To achieve the above purposes this study uses several models such as Gavaris's general linear model for standardizing fishing efforts, surplus production method for estimating biological and technological coefficients, current value Hamiltonian method for estimating dynamic optimal harvest and efforts, and sensitivity analysis for diagnosing economic influences of these fisheries. As a result, this study showed that Spanish mackerel was overfished by multiple fishing gears based on surplus production method and the current value Hamiltonian method. Also, this study found that when the price and cost proportionally changed, the optimal harvest and fishing effort sensitively responded to the stock level of Spanish mackerel. Next, this study suggested that the multiple fishing gears for Spanish mackerel should reduce unnecessary costs such as operating time or inefficient fuel consumption. Finally, this study provided reasons Spanish mackerel should be included in the TAC system in a view of profit maximization based on sustainable use of the Spanish mackerel.

• Korean Journal of Medicinal Crop Science
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• v.6 no.3
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• pp.227-231
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• 1998

Flowering characteristics and optimal harvest time for seed of wasabi variety. Daruma, were investigated from Dec. 1995 to June 1996 in film house of Suwon. The number of peduncle was $10.2{\pm}2.29$ and most of the peduncle emerged between Jan. 20 and Feb. 10. Average peduncle length was $124{\pm}29.60cm$ and the peduncle grew most rapidly in the middle of march. Flowering started on Jan. 27 and lasted until June 4 with a peak at march 21 and flowering period was $99{\pm}21.32$ days. Flowers which bloomed later than the middle of March set seed but those bloomed earlier became sterile because days with minimum temperature below freezing occurred until the middle of March. Maturing period was $37.5{\pm}2.60$ days and total seed set was $43.2{\pm}8.77%$ in the natural culture condition. Optimal harvest time for seed was the last ten days of May and seed yield per $m^2$ was $79.0{\pm}19.94g%$(11,177 seeds).