• 한국산림과학회지
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• 제111권4호
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• pp.644-650
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• 2022

두릅나무는 두릅나무과에 속하는 낙엽활엽관목으로 전국에서 재배되고 있는 고소득 작목이다. 재배의 효율성 제고 및 소득 증대를 위하여 두릅나무의 새순 수확 후 전정 시기 및 연차별 전정에 따른 생산성을 분석하였다. 두릅나무 새순 수확 직후 6일 뒤부터 2주 간격으로 5회 전정하여 최적 시기를 판단하였다. 또한 전정 효과를 규명하기 위하여 정식 후 1년 차에 지상에서 30 cm 높이로 전정하였다. 정식 후 2년 차부터 전년도 발생한 가지를 10 cm 남기고 전정하였으며, 연차별 새순 및 가지 발생 특성을 비교하였다. 그 결과 새순 수확 종료 후 6일이 지난 뒤 처음 전정한 두릅나무의 가지 수가 다른 시기보다 1.3-2.1배 많았다. 새순 특성 또한 다른 시기보다 1.2-1.7배 우수하였으며, 전정이 빠를수록 품질이 좋은 많은 양의 새순을 수확할 수 있었다. 연차별 두릅나무의 전정을 통하여 정식 후 2년 차부터 고품질의 새순(직경 약 1.5 cm, 길이 약 16 cm)을 생산할 수 있었으며, 새순 수확이 가능한 가지 발생을 유도하여 생산성을 높일 수 있었다. 또한, 연차별 전정을 통하여 새순 수확이 쉬운 150 cm 정도의 수고를 유지 시킬 수 있었다. 그 결과 두릅나무의 전정 작업은 새순 수확 후 6일 전후로 빠른 시기에 시행하는 것이 효율적이다. 또한 전정하게 되면 매년 균일한 품질의 새순을 생산할 수 있고, 본당 수확량을 증가시킬 수 있다.

• 한국작물학회지
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• 제62권1호
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• pp.16-23
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• 2017

출수 후 수확일수에 따라 수량 및 사료가치를 고려해 보면 겉보리는 수량은 출수 후 24 일부터 42 일까지 유의적으로 증가하였으며(p<0.05), 36 일차 557 kg/10a 이었으며 39일, 42 일차와 유의적 차이를 보이지 않았다. 사료가치의 경우 조섬유, 조회분의 경우 유의적 차이를 보이나(p<0.05), 조단백질, 조지방, 가소화총영양성분(TDN)의 경우에는 유의적 차이를 보이지 않는다. 발효에 영향을 주는 pH 는 24일부터 36 일까지는 pH 3.8-4.2 까지 안정을 유지하다가 39 일차부터는 pH 5.2 로 증가하여 발효에 적합하지 않았다(p<0.05). 따라서 겉보리의 곡실발효사료 제조를 위한 겉보리 최적 수확시기는 출수 후 36 일차였다.

• 전기학회논문지P
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• 제58권4호
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• pp.455-460
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• 2009

A number of factors combine to make ultraviolet radiation a superior means of water purification for ground water, rainwater harvesting systems and so on. Ultraviolet radiation is capable of destroying all types of bacteria. Additionally, ultraviolet radiation disinfects rapidly without the use of heat or chemical additives which may undesirably alter the composition of water. In a typical operation, water enters the inlet of a UV lamp and flows through the annular space between the quartz sleeve and the outside chamber wall. The irradiated water leaves through the outlet nozzle. Several design features are combined to determine the dosage delivered. The first is Wavelength output of the lamp, the Second is Length of the lamp - when the lamp is mounted parallel to the direction of water flow, the exposure time is proportional to the length of the lamp, the third is Design water flow rate - exposure time is inversely related to the linear flow rate, the forth is Diameter of the purification chamber - since the water itself absorbs UV energy, the delivered dosage diminishes logarithmically with the distance from the lamp. In this paper, It describe the how to design optimal UV disinfection device for ground water and rainwater. To search the optimal design method, it was performed computer simulation with 3D-CFD discrete ordinates model and manufactured prototype. Using proposed design method manufactured prototype applied to disinfection test and proved satisfied performance.

• 농업과학연구
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• 제46권2호
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• pp.381-393
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• 2019

A smart farm is a system that combines information and communication technology (ICT), internet of things (IoT), and agricultural technology that enable a farm to operate with minimal labor and to automatically control of a greenhouse environment. Machine learning based on recently data-driven techniques has emerged with big data technologies and high-performance computing to create opportunities to quantify data intensive processes in agricultural operational environments. This paper presents research on the application of machine learning technology to diagnose the growth status of crops and predicting the harvest time of strawberries in a greenhouse according to image processing techniques. To classify the growth stages of the strawberries, we used object inference and detection with machine learning model based on deep learning neural networks and TensorFlow. The classification accuracy was compared based on the training data volume and training epoch. As a result, it was able to classify with an accuracy of over 90% with 200 training images and 8,000 training steps. The detection and classification of the strawberry maturities could be identified with an accuracy of over 90% at the mature and over mature stages of the strawberries. Concurrently, the experimental results are promising, and they show that this approach can be applied to develop a machine learning model for predicting the strawberry harvesting time and can be used to provide key decision support information to both farmers and policy makers about optimal harvest times and harvest planning.

• Journal of Communications and Networks
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• 제14권2호
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• pp.188-194
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• 2012

Cognitive networks (CNs) are capable of enabling dynamic spectrum allocation, and thus constitute a promising technology for future wireless communication. Whereas, the implementation of CN will lead to the requirement of an increased energy-arrival rate, which is a significant parameter in energy harvesting design of a cognitive user (CU) device. A well-designed spectrum-sensing scheme will lower the energy-arrival rate that is required and enable CNs to self-sustain, which will also help alleviate global warming. In this paper, spectrum sensing in a multi-user cognitive ad hoc network with a wide-band spectrum is considered. Based on the prospective spectrum sensing, we classify CN operation into two modes: Distributed and centralized. In a distributed network, each CU conducts spectrum sensing for its own data transmission, while in a centralized network, there is only one cognitive cluster header which performs spectrum sensing and broadcasts its sensing results to other CUs. Thus, a wide-band spectrum that is divided into multiple sub-channels can be sensed simultaneously in a distributed manner or sequentially in a centralized manner. We consider the energy consumption for spectrum sensing only of an analog-to-digital convertor (ADC). By formulating energy consumption for spectrum sensing in terms of the sub-channel sampling rate and whole-band sensing time, the sampling rate and whole-band sensing time that are optimal for minimizing the total energy consumption within sensing reliability constraints are obtained. A power dissipation model of an ADC, which plays an important role in formulating the energy efficiency problem, is presented. Using AD9051 as an ADC example, our numerical results show that the optimal sensing parameters will achieve a reduction in the energy-arrival rate of up to 97.7% and 50% in a distributed and a centralized network, respectively, when comparing the optimal and worst-case energy consumption for given system settings.

• Journal of Ecology and Environment
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• 제41권7호
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• pp.191-201
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• 2017

Background: Limited availability of corn stover due to the competing uses (organic manure, animal feed, bio-materials, and bioenergy) presents a major concern for its future in the bio-economy. Furthermore, biomass research has exhibited different results due to the differences in the supply of enzymes and dissimilar analytical methods. The effect of the two leading pretreatment techniques (dilute acid and alkaline) on glucose yield from three corn stover fractions (cob, stalk, and leaf) sourced from a single harvest in Uganda were studied at temperatures 100, 120, 140, and $160^{\circ}C$ over reaction times of 5, 10, 30, and 60 min. Results: From this study, the highest glucose concentrations obtained from the dilute acid (DA) pretreated cobs, stalks, and leaves were 18.4 g/L (66.8% glucose yield), 16.2 g/L (64.1% glucose yield), and 11.0 g/L (49.5% glucose yield), respectively. The optimal pretreatment settings needed to obtain these yields from the DA pretreated samples were at a temperature of $160^{\circ}C$ over an incubation time of 30 min. The highest glucose concentrations obtained from the alkaline (AL) pretreated cobs, stalks, and leaves were 24.7 g/L (81.73% glucose yield), 21.3 g/L (81.23% glucose yield), and 15.0 g/L (51.92% glucose yield), respectively. To be able to achieve these yields, the optimal pretreatment settings for the cobs and stalks were $140^{\circ}C$ and for a retention time of 30 min, while the leaves require optimal conditions of $140^{\circ}C$ and for a retention time of 60 min. Conclusions: The study recommends that the leaves could be left on the field during harvesting since the recovery of glucose from the pretreated cobs and stalks is higher.

• 한국초지조사료학회지
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• 제37권4호
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• pp.264-270
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• 2017

이 연구는 배합사료 대체용 분쇄사일리지를 조제하기 위한 보리와 밀의 적정 수확시기와 사료가치 및 발효품질을 구명하고자 실시하였다. 그 결과, 수분함량은 새쌀보리와 금강밀 모두 수확시기가 늦어짐에 따라 감소하는 경향을 보였는데, 수분감소는 새쌀보리가 금강밀보다 더 빠르게 진행되었다. 생육특성에서 수확시기에 따른 초장길이의 변화는 없었고, 경수는 감소하는 경향을 보였다. 건물수량과 TDN수량은 새쌀보리는 출수 후 35일과 40일에서 출수 후 30일보다 유의적으로 높은 값을 보였고, 금강밀은 출수 후 40일과 45일에서 출수 후 35일보다 유의적으로 높은 값을 보였다(p<0.05). 조단백질 함량은 수확시기가 늦어질수록 새쌀보리와 금강밀 모두 증가하는 경향을 보였고, 조섬유, 조지방 및 조회분함량은 수확시기가 늦어짐에 따라 비슷하거나 약간 낮아지는 경향을 보였으나 통계적인 유의성은 없었다. NDF와 ADF 함량은 수확시기가 늦어짐에 따라 새쌀보리는 감소하는 경향을 보였고, 금강밀은 비슷한 경향을 보였으며, TDN 함량은 수확시기에 따라 새쌀보리는 다소 증가하는 경향을 보였으나, 금강밀은 비슷한 값을 나타냈다. 총체분쇄 사일리지의 발효 전 후 사료가치는 일반성분들이 약간 증가되는 경향이 있었지만 통계적인 유의성은 없었다. 발효품질면에서 수확시기가 늦어짐에 따라 새쌀보리는 pH가 높아지고 젖산함량이 유의적으로 낮아졌으며(p<0.05), 금강밀은 pH가 비슷한 값을 보였고, 젖산함량은 낮아지는 경향을 나타냈다. 따라서 총체분쇄 사일리지를 조제하기 위한 적정 수확시기는 수량성과 품질을 같이 고려해보면 새쌀보리는 출수 후 35일이 적절하고, 금강밀은 출수 후 40~45일이 적절할 것으로 사료된다.

• 농업과학연구
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• 제40권4호
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• pp.271-276
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• 2013

This experiment was carried out to determine optimal culture conditions for the production of tubers of Calla (Zantedeschia elliottiana 'Golden Affair' and 'Black Magic') in Korea highland. In vitro produced plantlets and tuberlets of Calla 'Golden Affair' and 'Black Magic' were planted plastic film greenhouse and grown for 100, 120, 140 days, with different night temperature treatments ($0{\sim}10^{\circ}C$ : no heating, 10, $15^{\circ}C$). In both cultivars, tuber size(tuber diameter, tuber height) and tuber weight increased with increasing cultivation period when the night temperature was maintained at $10^{\circ}C$. The largest tuber diameter in vitro produced plantlets was 5.8cm in 'Black Magic' and 3.2cm in 'Golden Affair', and daily tuber growth rate was 1.110g in 'Black Magic' and 0.092g in 'Golden Affair' under the culture conditions. Consequently we think that tuber harvest date was Oct. 30 and night temperature was $10^{\circ}C$ and no heating that was proper method of tuber production. However we had selection of $10^{\circ}C$ treatment for tuber production because it appeared freezing damage occasionally in highland late in October.

• 한국포장학회지
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• 제29권3호
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• pp.223-228
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• 2023

Sustainable energy supplies without the recharging and replacement of the charge storage device have become increasingly important. Among various energy harvesters, the triboelectric nanogenerator (TENG) has attracted considerable attention due to its high instantaneous output power, broad selection of available materials, eco-friendly and inexpensive fabrication process, and various working modes customized for target applications. In this study, the amount of voltage and current generated was measured by applying the PSD profile random vibration test of the electronic vibration tester and ISTA 3A according to the time of Anodized Aluminum Oxide (AAO) pore widening of the manufactured TENG device Teflon and AAO. The discharge and charging tests of the integrated module during the random simulated transport environment and the recognition distance of RFID were measured while agricultural products (onion) were loaded into the returnable folding plastic box. As a result, it was found that AAO alumina etching processing time to maximize TENG performance was optimal at 31 min in terms of voltage and current generation, and the integrated module applied with the TENG module showed a charging effect even during the continuous use of RFID, so the voltage was kept constant without discharge. In addition, the RFID recognition distance of the integrated module was measured as a maximum of 1.4 m. Therefore, it was found that the surface condition of AAO, a TENG element, has a great influence on the power generation of the integrated module, and due to the characteristics of TENG, the power generation increases as the surface dries, so it is judged that the power generation can be increased if the surface drying treatment (ozone treatment, etc.) of AAO is applied in the future.

• 한국작물학회:학술대회논문집
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• 한국작물학회 2005년도 춘계학술발표회 요지
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• pp.76-77
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• 2005