• Journal of Biosystems Engineering
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• 제39권3호
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• pp.194-204
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• 2014

Purpose: The aim of this study was to develop long-term storage technology for Chinese cabbage in order to extend the period of availability of freshly harvested products. The scope of the paper deals with the use of a cooler with a remote monitoring and control interface in conjunction with use of packaging film. Methods: A cooler with a real time monitoring system was designed as a low-temperature storage facility to control temperature and relative humidity (RH). The effects of storage in high-density polyethylene (HDPE) plastic boxes, 3% chitosan dipping solution, polypropylene film (PEF) with perforations, and mesh packaging bags on physiological responses were investigated. The optimal storage temperature and humidity for 120 days were below $0.5^{\circ}C$ and 90%, respectively. Physiological and biochemical features of cabbage quality were also analyzed: weight loss, texture, and sugar salinity, chlorophyll, reducing sugar, and vitamin C contents. Results: The cooler with a remote monitoring and control interface could be operated by an HMI program. A $0.5^{\circ}C$ temperature and 90% humidity could be remotely controlled within the cooler for 120 days. Postharvest freshness of Chinese cabbages could be maintained up to 120 days depending on the packaging method and operation of the remote monitoring system. In particular, wrapping the cabbages in PEF with perforations resulted in a less than a 5% deterioration in quality. This study provides evidence for efficient performance of plastic films in minimizing post-harvest deterioration and maintaining overall quality of cabbages stored under precise low-temperature conditions with remote monitoring and a control interface. Conclusions: Packaging with a modified plastic film and storage in a precisely controlled cooler with a remote monitoring and control interface could slow down the physiological factors that cause adverse quality changes and thereby increase the shelf life of Chinese cabbage.

• International Journal of Computer Science & Network Security
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• 제24권1호
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• pp.151-155
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• 2024

This project is designed with the aim to facilitate the farmer or gardener to engage in green house systems and to improve agricultural technology. In order to reduce continuous monitoring of the soil parameters, excess time consumption for the farmers and excessive usage of water, "Smart irrigation and temperature control for a greenhouse system" has been developed. There are two different ways to irrigate the land namely traditional irrigation methods and modern irrigation methods.

• 한국식품과학회지
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• 제4권2호
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• pp.84-89
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• 1972

An experiment was carried out to investigate the optimum doses of gamma-irradiation for sprouting inhibition of onion bulbs with irradiation time and storage conditions. The results. obtained are as follows: 1) The irradiation doses of 5, 7 and 10 krad, respectively, at 11, 32 and 66 days after harvest were sufficient to inhibit subsequent sprout of onion bulbs obtained from Nampyeong district. When they were irradiated at 96 day after harvest, however, there was little sprout-inhibition by 15 krad. In case of onion bulbs obtained from Changnyeong district, sprout was inhibited by doses of 8 and 12 krad respectively, at 51 and 89 days after harvest. 2) Low-temperature storage after irradiation was not effective in sprout-inhibition of onion bulbs. Onion bulbs stored at low temperature of $5^{\circ}C$ rather showed higher sprouting rate as compared with that of room temperature. 3) Rot increased in irradiated lot and at room temperature, and spores of Aspergillus sp. were little germinated at a level of 100 krad. 4) The respiratory rate of irradiated onion bulbs was higher immediately after irradiation but lower one week after irradiation than control. Respiratory quotient of tissues seems to be little affected by gamma-irradiation.

• Agricultural and Biosystems Engineering
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• 제7권1호
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• pp.1-7
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• 2006

A need exists to monitor and control the localized high temperatures often experienced in solar grain dryers, which result in grain cracking, reduced germination and loss of cooking quality. A verified finite element model would be a useful to monitor and control the drying process. This study examined the feasibility of the finite element method (FEM) to predict temperature distribution in solar grain dryers. To achieve this, an indirect solar grain dryer system was developed. It consisted of a solar collector, plenum and drying chambers, and an electric fan. The system was used to acquire the necessary input and output data for the finite element model. The input data comprised ambient and plenum chamber temperatures, prevailing wind velocities, thermal conductivities of air, grain and dryer wall, and node locations in the xy-plane. The outputs were temperature at the different nodes, and these were compared with measured values. The ${\pm}5%$ residual error interval employed in the analysis yielded an overall prediction performance level of 83.3% for temperature distribution in the dryer. Satisfactory prediction levels were also attained for the lateral (61.5-96.2%) and vertical (73.1-92.3%) directions of grain drying. These results demonstrate that it is feasible to use a two-dimensional (2-D) finite element model to predict temperature distribution in a grain solar dryer. Consequently, the method offers considerable advantage over experimental approaches as it reduces time requirements and the need for expensive measuring equipment, and it also yields relatively accurate results.

• Journal of the Korean Wood Science and Technology
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• 제51권6호
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• pp.493-508
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• 2023

Round timber materials of 600 mm length, cut from large-cross-section round timber of red pine (Pinus densiflora S. et Z.) of 450 mm width and 4.2 m length, were prepared as the target of kiln drying in this study. After treating the target materials through end sealing (ES), end sealing - kerfing (ES-K), lateral sealing - end sealing - boring (LS-ES-B), or lateral sealing - partial end sealing (LS-PES), the effects of the treatment on the incidence of drying defects were determined. The target materials with exposed lateral surface and sealed cross surface were steamed at the initial temperature of 65℃ above the official pest control temperature of 56℃, followed by kiln drying toward the final temperature of 75℃. The target materials with sealed lateral surfaces, on the other hand, were dried at the initial temperature of 90℃ at almost the maximum temperature of conventional kiln drying, as there is no risk of early check formation caused by surface moisture evaporation. The final temperature was set at approximately 100℃. The drying time, taken for the target materials with initial moisture content of 70%-80% to reach the target moisture content of 19%, varied across treatment conditions. The measured drying time was 1,146 hours (approximately 48 days) for the timber with sealed cross surface and 745 hours (approximately 31 days) for the timber with sealed lateral surface, until the moisture content reached the target level. The formation of surface checks could not be prevented in the control and ES groups, but a definite preventive effect was obtained for the LS-ES-B and LS-PES groups.

• Journal of the Korean Wood Science and Technology
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• 제42권2호
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• pp.101-111
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• 2014

In this study the effect of heartwood-coating (HCO), vapor-dam (VD), bark-remaining (BR) and bark-remaining-coating (BRC) treatments on the air circulating oven-drying characteristics of Japanese larch hollowed round-post was evaluated. The drying times of the hollowed round-posts for control, VD, HCO and BR specimens were 72, 168, 204 and 240 hours, respectively, from the initial MC to about 8% MC, which was recommended as the indoor in-use MC. The temperature in the hole of the VD specimen was lower than that of wood and the difference between air temperature in the hole and wood temperature became large during drying period. The vapor pressure of air in the hole was higher than that of inside wood for all specimens except VD specimen. The surface checks on all specimens were observed in increasing order of BR, BRC, UC, HCO and VD specimens.

• 생물환경조절학회지
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• 제16권3호
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• pp.174-179
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• 2007

참외 발효과 발생에 영향을 미치는 증산과 관련된 몇 가지 요인을 검토한 결과는 다음과 같다. 참외의 증산율은 지온이 높고 토양수분 함량이 많을수록 높았으며, 광도가 약하여 온도가 낮을 경우 증산율과 기공 전도도가 낮아졌고, 저온 다습한 기상조건에 의한 증산의 억제는 식물체와 대기사이의 증기압기울기가 낮아지는 것으로 생각된다. 발효과 발생은 과실의 비대가 느린 착색기 이후에 토양수분이 -10 kPa로 많고, 저온 다습하여 참외와 대기 사이에 증기압기울기가 낮게 형성되어 증산이 억제될 때 발생하였다. 따라서 참외의 발효과 발생은 착색기 이후 참외의 과실 비대가 지연되는 반면 지온이 높아 뿌리로부터 지상부로 수분의 공급이 원활하고, 저온 다습한 기상조건하에 수분의 증산이 억제되어 수분이 태좌부로 유입되면 발효과가 발생되는 것으로 생각된다.

• 한국농공학회논문집
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• 제64권5호
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• pp.27-39
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• 2022

The smart farm is recognized as a solution for future farmers having positive effects on the sustainability of the poultry industry. Intelligent microclimate control can be a key technology for broiler production which is extremely vulnerable to abnormal indoor air temperatures. Furthermore, better control of indoor microclimate can be achieved by accurate prediction of indoor air temperature. This study developed predictive models for internal air temperature in a mechanically-ventilated broiler house based on the data measured during three rearing periods, which were different in seasonal climate and ventilation operation. Three machine learning models and a mechanistic model based on thermal energy balance were used for the prediction. The results indicated that the all models gave good predictions for 1-minute future air temperature showing the coefficient of determination greater than 0.99 and the root-mean-square-error smaller than 0.306℃. However, for 1-hour future air temperature, only the mechanistic model showed good accuracy with the coefficient of determination of 0.934 and the root-mean-square-error of 0.841℃. Since the mechanistic model was based on the mathematical descriptions of the heat transfer processes that occurred in the broiler house, it showed better prediction performances compared to the black-box machine learning models. Therefore, it was proven to be useful for intelligent microclimate control which would be developed in future studies.

• Journal of the Korean Wood Science and Technology
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• 제22권1호
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• pp.12-19
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• 1994

An electrically heated experimental lumber dry kiln was retrofitted with a computer-based control system to control kiln conditions more precisely and monitor and record several kiln variables. Flat-sawn 2.5cm-thick Pinus densiflora boards were dried in constant temperature process(65$^{\circ}C$ & 50~60 %RH) and continuously rising temperature process, respectively. The average drying rate in continuously rising temperature process was 5.7 %/hr, which was above 3 times faster than that in constant temperature process. But, the average rate of case-hardening and moisture difference between shells and cores of boards dried in continuously rising temperature process were 82 % and 5.5 %, respectively, which were much larger than those of boards dried in constant temperature process.

• Journal of the Korean Wood Science and Technology
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• 제37권3호
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• pp.192-199
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• 2009

본 연구에서는 수용재적 약 $3m^3$ 크기의 압체고주파진공건조시스템을 이용하여 Azobe (Lophira alata)와 국산 소나무(Pinus densiflora) 제재목을 건조하면서 건조시스템의 성능을 평가하였다. 압체고주파진공건조기의 진공도는 80~105 mbar를 유지시켰고, 건조 중 재온은 건조초기 $40^{\circ}C$에서 시작하여 건조말기 $60^{\circ}C$까지 상승시켰다. 全건조기간에 걸쳐 기전전극판측의 재온은 제어온도보다 항상 높게 유지되는 반면, 접지전극판측의 재온은 항상 낮게 유지되었다. 건조시간이 경과함에 따라 접지전극판측의 재온은 제어온도보다 더욱 낮고 기전전극판측의 재온은 제어온도보다 더욱 높게 나타났다. Azobe의 경우 입력포트측의 평균최종함수율보다 입력포트반대측의 평균최종함수율이 모든 잔적층에서 미미하게 높게 나타났으며, 잔적층의 수직방향으로의 최종함수율은 기전전극판측에서 접지전극판측을 향할수록 높게 나타났다. 기전전극판과 인접한 잔적층의 경우 재목당 평균할렬의 발생길이가 매우 경미하였으나, 접지전극판측을 향할수록 증가하는 경향을 보였다. 또한 투입된 에너지의 효율면에 있어 선진국의 상용설비와 유사한 수준을 보여 주는 것으로 평가되었다.