• Proceedings of the Korean Society of Agricultural Engineers Conference
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• 1998.10a
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• pp.217-223
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• 1998

This study was performed to figure out water consumption of the twisted sweet pepper in a greenhouse. Obtained results are as follows; 1. The ambient temperature was nearly same as the normal year, while the average air temperature and the relative humidity in the green house were little bit higher than those of the outside condition. The transparency of the greenhouse roof was approximately 50%. The total amount of rainfall during the irrigation period was 1,040㎜ which is 350㎜ higher than 1997 during the same period. 2. In case of pot cultivation, as the saturation ratio was increased, the aeaf area and plant height and yield were also increased. The yield from the field cultivation was higher than the average yield from the pot cultivations which are treated by three levels of saturation ratio. 3. The variation of daily consumptive use of the twisted sweet pepper was very large in it's range. In case of the pot cultivation, as the saturation was increased, the daily and the total consumptive use were increased. 4. The daily consumptive use was strongly correlated with the ambient temperature, while it was weakly correlated with the relative humidity and solar radiation. 5. There were close correlation between plant environment; leaf area, plant height and yield, and consumptive use. As the saturation ratio was increased, the correlation between those plant factors and consumptive use was getting stronger.

• Journal of Biosystems Engineering
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• v.39 no.1
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• pp.47-56
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• 2014

Purpose: In protected crop production facilities such as greenhouse and plant factory, farmers should be present and/or visit frequently to the production site for maintaining optimum environmental conditions and better production, which is time and labor consuming. Monitoring of environmental condition is highly important for optimum control of the conditions, and the condition is not uniform within the facility. Objectives of the paper were to investigate spatial and vertical variability in ambient environmental variables and to provide useful information for sensing and control of the environments. Methods: Experiments were conducted in a strawberry-growing greenhouse (greenhouse 1) and a cherry tomato-growing greenhouse (greenhouse 2). Selected ambient environmental variables for experiment in greenhouse 1 were air temperature and humidity, and in greenhouse 2, they were air temperature, humidity, PPFD (Photosynthetic Photon Flux Density), and $CO_2$ concentration. Results: Considerable spatial, vertical, and temporal variability of the ambient environments were observed. In greenhouse 1, overall temperature increased from 12:00 to 14:00 and increased after that, while RH increased continuously during the experiments. Differences between the maximum and minimum temperature and RH values were greater when one of the side windows were open than those when both of the windows were closed. The location and height of the maximum and minimum measurements were also different. In greenhouse 2, differences between the maximum and minimum air temperatures at noon and sunset were greater when both windows were open. The maximum PPFD were observed at a 3-m height, close to the lighting source, and $CO_2$ concentration in the crop growing regions. Conclusions: In this study, spatial, vertical, and temporal variability of ambient crop growing conditions in greenhouses was evaluated. And also the variability was affected by operation conditions such as window opening and heating. Results of the study would provide information for optimum monitoring and control of ambient greenhouse environments.

• Journal of Mushroom
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• v.13 no.1
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• pp.26-29
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• 2015

Since button mushroom (Agaricus bisporus) cultivation is performed in closed environment, the understanding of indoor environment becomes essential for the quality and quantitative production of the greenhouse-grown mushroom. To generate information on indoor environmental factors affecting on fruiting body quality, we investigated temperature, humidity, and bacterial concentration and species in a greenhouse located in Buyeo, Chungnam Province. Temperature and humidity were recorded as $19.75{\pm}0.35^{\circ}C$ and $87{\pm}3.67%$, respectively. The total concentration of bacteria was measured as $3.84{\times}10^3CFU/M^3$. Advenella kashmirensis, Bacillus vietnamensism, B. licheniformis, Burkholderia sordidicola, Fictibacillus phosphorivorans, Lysobacter daejeonensis, Microbacterium esteraromaticum, Pseudomonas aeruginosa, P. protegens, P. gessardii, P. mosseli were identified from indoor air of the greenhouse.

• Proceedings of the Korean Society for Bio-Environment Control Conference
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• 2000.10a
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• pp.38-41
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• 2000

• Proceedings of the Korean Society for Bio-Environment Control Conference
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• 2000.10a
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• pp.90-93
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• 2000

• Atmosphere
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• v.33 no.5
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• pp.549-560
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• 2023

This study evaluates three distinct observation methods, CRDS, OA-ICOS, and OF-CEAS, in greenhouse gas monitoring equipment for atmospheric CO₂ and CH₄ concentrations. The assessment encompasses fundamental performance, high-concentration measurement accuracy, calibration methods, and the impact of atmospheric humidity on measurement accuracy. Results indicate that within a range of approximately 500 ppm, all three devices demonstrate high accuracy and linearity. However, beyond 1000 ppm, CO₂ accuracy sharply declines (84%), emphasizing the need for caution when interpreting high-concentration CO₂ data. An analysis of calibration methods reveals that both CO₂ and CH₄ measurements achieve high accuracy and linearity through 1-point calibration, suggesting that multi-point calibration is not imperative for precision. In dynamic atmospheric conditions with significant CO₂ and CH₄ concentration variations, a 1-point calibration suffices for reliable data (99% accuracy). The evaluation of humidity impact demonstrates that humidity removal devices significantly reduce air moisture levels, yet this has a negligible effect on dry CO₂ concentrations (less than 0.5% relative error). All three observation method instruments, which have integrated humidity correction to calculate dry CO₂ concentrations, exhibit minor sensitivity to humidity removal devices, implying that additional removal devices may not be essential. Consequently, this study offers valuable insights for comparing data from different measurement devices and provides crucial information to consider in the operation of monitoring sites.

• Journal of Biosystems Engineering
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• v.28 no.1
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• pp.53-58
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• 2003

This study was carried out to design, construct, and test a greenhouse monitoring system fur the environment and status of control devices in a greenhouse from a remote site using internet. The measuring items selected out of many environmental factors were temperature, humidity, solar radiation, CO$_2$, SOx, NOx concentration, EC, pH of nutrient solution, the state of control devices, and the image of greenhouse. The developed greenhouse monitoring system was composed of the network system and the measuring module. The network system consists of the three kinds of monitors named the Croup Monitor. the Client Monitor and the Server Monitor. The results of the study are summarized as follows. 1. The measuring module named the House Monitor. which is used to watch the state of the control device and the environment of the greenhouse, was developed to a embedded monitoring module using one chip microprocessor 2. For all measuring items. the House Monitor showed a satisfactory accuracy within the range of ${\pm}$0.3%FS. The House Monitors were connected to the Croup Monitor by communication method of RS-485 type and could operate under power and communication fault condition within 10 hours. The Croup Monitor was developed to receive and display measurement data received from the House Monitors and to control the greenhouse environmental devices. 3. The images of the plants inside greenhouse were captured by PC camera and sent to the Group Monitor. The greenhouse manager was able to monitor the growth state of plants inside greenhouse without visiting individual greenhouses. 4. Remote monitoring the greenhouse environment and status of control devices was implemented in a client/server environment. The client monitor of the greenhouse manager at a remote site or other greenhouse manager was able to monitor the greenhouse environment and the state of control devices from the Server Monitor using internet.

• Magazine of the Korean Society of Agricultural Engineers
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• v.43 no.4
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• pp.50-56
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• 2001

In order to provide basic information for the estimation of reference crop evapotranspiration in the greenhouse on experiment was performed. Daily evapotranspiration of the reference crop wear measured using lysimeters. kentucky Blue Grass was used as a reference crop. Climatic elements I the greenhouse such as air temperature relative humidity and radiation were measured. The influence of each climatic element on the evapotranspiration were analyzed. A multi-regression model for the estimation of reference crop evapotranspiration in the greenhouse was developed and tested simulated evapotranspiration by the model were in good agreement with measured evapotransiration.

• Proceedings of the Korean Society for Bio-Environment Control Conference
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• 1999.11a
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• pp.122-125
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• 1999

Ventilation is the primary method of controlling greenhouse air temperature, relative humidity, and carbon dioxide concentration. Two types of ventilation systems that are normally used are natural and fan. While fan ventilation is typically achieved with one wall as an inlet and the opposite wall as a fan outlet, natural ventilation is generally achieved by air exchanges that occur through multiple controlled openings due to natural pressure variations inside and outside the greenhouse. (omitted)

• Journal of Bio-Environment Control
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• v.27 no.1
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• pp.20-26
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• 2018

This study was conducted to develop a device for measuring the air flow by space variation through monitoring program, which acquires data by each point from each environmental sensor located in the greenhouse. The distribution of environmental factors(air temperature, humidity, wind speed, etc.) in the greenhouse is arranged at 12 points according to the spatial variation and a large number of measurement points (36 points in total) on the X, Y and Z axes were selected. Considering data loss and various greenhouse conditions, a bit rate was at 125kbit/s at low speed, so that the number of sensors can be expanded to 90 within greenhouse with dimensions of 100m by 100m. Those system programmed using MATLAB and LabVIEW was conducted to measure distributions of the air flow along the greenhouse in real time. It was also visualized interpolated the spatial distribution in the greenhouse. In order to verify the accuracy of CFD modeling and to improve the accuracy, it will compare the environmental variation such as air temperature, humidity, wind speed and $CO_2$ concentration in the greenhouse.