• The Journal of the Korea institute of electronic communication sciences
• /
• v.8 no.5
• /
• pp.745-750
• /
• 2013

In many recent studies, a variety of environmental control system for practical gardening facilities such as facility house and plant factory have been proposed. However, the plants have been exposed to growth disorder and disease and pest injury because the temperature and humidity have not properly controlled so far. Therefore, a lot of damage of farmers have been reported. The air circulation fan and industrial dehumidifier have been currently utilized as the countermeasures, but they do not meet the expectation. In this study, the growth phase of each plant is recognized by using cycle-by-cycle plants growth recogniztion algorithm to provide optimal environment according to the growth phases of each plant.he productivity can be raised by using cycle-by-cycle plant growth recognition monitoring system because it optimally controls the environment by cycle that is required for plant growth.

• Journal of Applied Tourism Food and Beverage Management and Research
• /
• v.15 no.2
• /
• pp.57-72
• /
• 2004

This study is carried out to investigate the effect of any periods in the freezer and the product of value, moisture content, baking loss, specific volume loaf in manufncturing process thereof. The moisture content of the croissant slightly decreased as the periods passed in the freezer. And as passed periods frozen croissant dough dried naturally by the freezer fan. 1. As frozen periods passed croissant dough decreased moisture content and loaf volume. The volume is relation to the molsture content and croissant dough' gluten. Yeast is active but croissant dough is dried so pastry margarine's moisture vaporized little by little. 2. 1 day frozen bench time provided maximum specific loaf volume while croissant shape was unsettled, moisture content was highest. At the same dough croissant hardness had very sofi crust. 3. 1week and 2weets frozen dough had specific loaf volume and hardness with proper crust color. As the proper bench time provided best shape of croissant, color. 4. 4weeks and 8weeks frozen dough had over-al] value of croissant accelerating older product. As the same result, over Sweets frozen periods product were not available for sale and serving to customers. 5. By the sensory evaluation tests, over-all croissant as 1 week, 2weeks were significantly higher quality those than 6. 1day, 4weeks and 8weeks. Textural properties of croissant over 4weeks frozen periods so hard for every panel. According to the study, not croissant dough but also any other frozen dough(ex.Danish, brioche etc.)have to need proper bench time and 1week or 2weeks circulation making method have to given encouragement to practical pastry industry. Add to this study using only for frozen dough yeast instead of using fresh and instant

• Journal of the Korea Institute of Information and Communication Engineering
• /
• v.24 no.10
• /
• pp.1325-1330
• /
• 2020

New-born babies who require special attention medically are admitted often to incubator. Incubators are well equipped to fulfill take care of infants, but they have to hospital and so expensive. This paper proposes a smart incubator that can solve the problem of convenience and cost aspect of these incubators. Developed incubator enables near-field monitoring using Arduino Uno as the main control device and Bluetooth communication. The environment in the incubator measures temperature and humidity using a DHT22 sensor and the sound using a P5510 microphone. If the temperature and humidity data set by the user are lower or higher than the reference value, it is designed to operate the heating pad using the controller or turn on the fan to allow air circulation. The measured values in the incubator are displayed in real time on the user's smartphone monitoring screen and are programmed using app inventor. Developed incubators can help take care of infants at low cost in the home.

• Nuclear Engineering and Technology
• /
• v.55 no.3
• /
• pp.999-1008
• /
• 2023

Deformed fuel rods can cause a partial blockage of the flow area in a subchannel. Such flow blockage will influence the core coolant flow and further the core heat transfer during the reflooding phase and subsequent severe accidents. Nevertheless, most of the system analysis codes simulate the accident process based on the assumed flow blockage ratio, resulting in inconsistencies between simulated results and actual conditions. This paper aims to study the influence of flow blockage in severe accident scenario of the CAP1400 reactor. First, the flow blockage model of ISAA code is improved based on the FRTMB module. Then, the ISAA-FRTMB coupling system is adopted to model and calculate the QUENCH-LOCA-0 experiment. The correctness and validity of the flow blockage model are verified by comparing the peak cladding temperature. Finally, the DVI Line-SBLOCA accident is induced to analyze the influence of flow blockage on subsequent CAP1400 reactor core heat transfer and core degradation. From the results of the DVI Line-SBLOCA accident analysis, it can be concluded that the blockage ratio is in the range of 40%-60%, and the position of severe blockage is the same as that of cladding rupture. The blockage reduces the circulation area of the core coolant, which in turn impacts the heat exchange between the core and the coolant, leading to the early failure and collapse of some core assemblies and accelerating the core degradation process.

• Nuclear Engineering and Technology
• /
• v.56 no.4
• /
• pp.1538-1543
• /
• 2024

The importance of determining the radon exhalation rate from water surface is emphasized by the increased use of radon and its daughter products as tracers in large-scale circulation studies of the atmosphere. There were many methods to measure radon exhalation from water surface. With the development of radon exhalation rate measurement methods and instruments on the surface of the soil, the rock and building materials, so the radon exhalation rate from water surface can be more accurately measured by applying these improved methods and instruments. In this paper, a cuboid accumulation chamber surrounded by foam boards and a RAD7 were used to measure the radon exhalation rate on the water surface at three different positions by Yixin lake. Each measurement was performed 2 h. The radon exhalation rate from the water surface was about 6 × 10^-3 Bq m^-2s^-1. The thoron exhalation rate from the water surface also can be estimated, it is about 0.16 Bq m^-2s^-1. These results hint that the radon transmission from the lake bottom soil to water and then into the atmosphere.

• Journal of Bio-Environment Control
• /
• v.30 no.4
• /
• pp.383-392
• /
• 2021

It has been known that oyster mushrooms cultivated in facilities with thermal insulation have been strongly affected by inner environments. Forced air-circulation fans exert much direct influence on disturbing air inside the facility so the matter is of particular interest. This study is carried out to investigate the measured levels of air uniformity in a cultivation facility for oyster mushroom in the various cases that reversibly controlled air-circulation fans which drove the flow in the upward and reverse direction by turn and unidirectional fans by which the wind blew upwards only were operated from July 1 to 10. The actual survey for the selection of ongoing operation cases presented that farmers, even though there were some discrepancies, have made use of fans in a way that it paused for 5-30min after running for 5-15min by turn. The level of air uniformity in the case of adopting reversible fans revealed a slight difference of 1.4-1.8℃ (Temp.) and 7.8-8.7% (R.H.) under the condition of not using a cooler during the investigation period. By contrast, unidirectional fans showed a noticeable difference of 3.2-3.7℃ and 14.0-15.4%, which meant that air uniformity driven by reversible fans much more increased compared to that for unidirectional fans. Among the twenty operational applications considered for reversible fans, the circumstance that the wind blew upwards for 10-15min and ceased for 5-10min and blew again in the reverse direction for 10-15min in succession gave minor improvements at the level of air uniformity, but at present there was somewhat difficult to make decision on which cases were optimally best. It seems necessary that the effects of reversible fans on air uniformity as well as qualities of oyster mushrooms have to be appraised in the cultivation period and the flow visualization needs to be done to ascertain the performance of air mixture.

• The Korean Journal of Mycology
• /
• v.47 no.4
• /
• pp.385-392
• /
• 2019

Currently, plastic bags are being used for sawdust cultivation of shiitake mushroom. However, due to serious environmental problems caused by the use of plastic bags, we studied the efficacy of bottle cultivation method to replace the sawdust bag method. Small detachable plastic bottles (400 g capacity) filled with Quercus spp. sawdust and wheat bran (4:1 w/w) media were incubated for 80 and 120 days. The weight loss (%) of the media was higher for the NIFoS 2464 strain at an approximate light intensity of 300 Lux than light intensity of 500 Lux; the light intensity was associated with the loss of sawdust medium-weight during the cultivation period. The highest yield was observed when the strain was cultivated for 80 days under dark conditions, 40 days under 500 Lux light, and air circulation fan speed of 30 rpm. When incubated for 120 days, mushroom yield in the bottle media was higher at 40 days of light exposure than 20 days of light exposure. In the bottle media incubated for 80 days under dark conditions, the mushrooms fruited due to repetitive water spraying on the top of the media and light stimulation during the fruiting period. The media could be separated from the bottles because the media shrank after the first harvest. These separated plastic bottles could be re-used for mushroom cultivation, thereby reducing the amount of plastic waste.

• Journal of Bio-Environment Control
• /
• v.18 no.3
• /
• pp.215-224
• /
• 2009

A survey on the actual state of heating, cooling, ventilation, and air-flow and experimental measurement of temperature and humidity distribution in tomato greenhouse were performed to provide fundamental data required in the development of air-flow control technology. In single-span plastic houses, which account for most of 136 tomato greenhouses surveyed, roof windows, ventilation and air-flow fans were installed in a low rate, and installation specs of those facilities showed a very large deviation. There were no farms installed greenhouse cooling facilities. In the hot air heating system, which account for most of heating type, installation specs of hot air duct showed also a large deviation. The exhaust air temperature and wind speed in hot air duct also were measured to have a big difference depending on the distance from the heater. We are using the maximum difference as indicator to determine whether temperature distribution is uniform. However if the temperature slope is not identical in greenhouse, it can't represent the uniformity. We analyzed relation between the maximum difference and the uniformity of temperature and humidity distribution. The uniformity was calculated using the mean and standard deviation of data from 12 measuring points. They showed high correlation but were represented differently by linear in the daytime and quadratic in the nighttime. It could see that the uniformity of temperature and humidity distribution was much different according to greenhouse type and heating method. The installation guidelines for ventilation and air-flow fan, the spread of greenhouse cooling technology for year-round stable production, and improvement of air duct and heating system, etc. are needed.

• Journal of the Korea institute for structural maintenance and inspection
• /
• v.24 no.2
• /
• pp.9-14
• /
• 2020

Four developed patents have applied for a new type of Composite Cyclone Scrubber followed by the previous research (Cho and Kim, 2017), including dust reducing fan with filters. Regarding target installation and maintenance cost, 64% reduction for investment costs (6.2 billion won vs. 17 billion won) compared to existing road pollution reduction system, while social benefit costs increase by 43% compared to existing road pollution reduction measures (72.6 billion won vs. 50.8 billion won). The composition of the device is an air blower type spiral guide vane, and an injection pressure collecting dust efficiency. A nozzle varies Injection angle and contact range, spray liquid species (waterworks, salty water). The proposed patent tests are circulation water Time-by-Time Spray and collected 41.4% more increased micro dust since the sprayed water meets contaminated gas due to the 45° degree colliding, which is 141% increased conventional dust collector. (Ratio of collection over 85%). As regards the source of collection liquid, circulated rainwater and well water, we expect a huge amount of energy and economically saved eco-friendly system in our patent. Finally, the guided vane and metal filter reduced over 90% micro-dust, while sprayed water cleans the vane and filters, resultantly minimizing the maintenance budget. The preliminary evaluations of the developed design make it possible to reduce not only cheaper maintenance budget due to the characteristic water spraying but the cost of water comes from mainly rain and underground.

• Journal of The Korean Society of Agricultural Engineers
• /
• v.57 no.5
• /
• pp.51-60
• /
• 2015

In Korea, 69.4 % of duck farms had utilized conventional plastic greenhouses. In this facilities, there are difficulties in controlling indoor environments for raising duck. High rearing density in duct farms also made the environmental control difficult resulting in getting more stressed making their immune system weaker. Therefore, a facility is needed to having structurally enough solidity and high efficiency on the environmental control. So, new design plans of duck house have recently been conducted by National Institute of Animal Science in Korea. As a study in advance to establish standard, computational fluid dynamics (CFD) was used to estimate the aerodynamic problems according to the designs by means of overall and regional ventilation efficiencies quantitatively and qualitatively. Tracer gas decay (TGD) method was used to calculate ventilation rate according to the structural characteristics of duck houses including installation of indoor circulation fan. The results showed that natural ventilation rate was averagely 164 % higher than typically designed ventilation rate, 1 AER ($min^{-1}$). Meanwhile, mechanically ventilated duck houses made 81.2 % of summer ventilation rate requirement. Therefore, it is urgent to develop a new duck house considering more structural safety as well as higher efficiency of environmental control.