• Journal of Agricultural Extension & Community Development
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• v.11 no.1
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• pp.191-207
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• 2004

This study was focused on the development of greenhouse management and environmental control system using internet. The essence of this system were remote automatic control unit connected with greenhouse environmental control according to the growth stages of crops, The specific objectives of the study were; 1) to analyze need of greenhouse environmental remote control system, 2) to investigate the important functions related to greenhouse management program, 3) to explore the possibility of diffusing the system using internet.The study was carried out through review of related literature and need assessment from the research and extension workers in charge of greenhouse management using questionnaire survey, interview and field study. The results of the study were summarized as fallows: 1) About 89% of respondents responded positively on the need to establish automatic control system using internet. 2) The greenhouse management and environmental control system using internet was possible to control the greenhouse in remote, automatic, and simultaneous manner, and additionally by cellular phone in emergent situation. 3) The system was possible to precisely control the greenhouse environment, and it was able to connect the environmental control data with information on growth of crops. 4) By networking the farmer, extension educator of agricultural technology center and researcher, web based farm consulting was possible through the system. Based on the results of the study recommendations were suggested as follows: 1) Thorough spot inspections and field trials should be performed before the diffusion of this system. 2) The costs of the system installation and maintenance should be moderate. 3) The operation of the system should be simple and easy for tamers to adopt. 4) National support should be made to build better internet infrastructure in rural areas.

• The Transactions of the Korean Institute of Electrical Engineers D
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• v.53 no.9
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• pp.644-649
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• 2004

To control a greenhouse is to control environmental parameters in greenhouse. Controlled environments may be as simple as saran-covered shade houses or as complex as growth chambers. Although greenhouses are probably the most common example of a controlled environment used in agricultural/horticultural production, the type of controlled environment or system that is needed depends upon the climate, time of year, crops being produced and the environmental parameters that must be controlled. In this contribution puts emphasis on construction of automatic-controlled greenhouse system by personal computer.

• Journal of Bio-Environment Control
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• v.15 no.1
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• pp.1-7
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• 2006

This study was conducted to develop a system and an control algorithm for control the environment of a plant factory. The greenhouse control system for environmental control was largely composed of a computer and a PLC. The screen of control program was composed of a greenhouse figure which was included machinery and equipments for greenhouse, the graph of environmental factors of inside greenhouse and the image of greenhouse. In order to reduce temperature change, the operation time of ventilation window was changed by 3 stage according to difference between a target and present temperature. When is heating, a temperature variation was shown to be $16.7{\pm}0.8^{\circ}C$. When is cooling, a temperature variation was shown to be $23.1{\pm}0.6^{\circ}C$. When is humidifing, a humidity variation was shown to be $39.3{\pm}1.6^{\circ}C$ %RH. An environmental control system and a control algorithm were proved that it was shown a good performance in a control accuracy. So a computer control system should be adapted to a control system of a greenhouse and a plant factory.

• Journal of Service Research and Studies
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• v.11 no.2
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• pp.118-130
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• 2021

This study designs and validates a greenhouse complex environmental control algorithm with a multi-phase processing scheme that can combine and control actuators according to the degree of change in the greenhouse environment. The composite environmental control system is a system in which the complex environmental controller analyzes the information detected by sensors and operates appropriately actuators to maintain the crop growth environment. A composite environmental controller directs control devices driving actuators through a composite environmental control algorithm, which calculates the values necessary for the operation of the control devices. Most existing algorithms carry out control procedures on a single phase by iteration cycle, which can cause abnormal changes in the greenhouse environment due to errors in output. The proposed algorithm distributes control procedures over multiple phases: environmental control, environmental control, and device operation, and every iteration cycle, detects environmental changes in the environmental control phase first, and then combines control devices that can control the environment in the environmental control phase, and finally, performs the controls to derive the actuators in the device operation phase. The proposed algorithm is designed based on the analysis of the relationship between greenhouse environmental elements and control devices deriving actuators. According to verification analysis, the multi-phase processing scheme provides room to modify or supplement the setting value and enables the control devices to reflect changes in the associated environmental components.

• Journal of Environmental Science International
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• v.30 no.11
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• pp.907-914
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• 2021

In this study, strawberry cultivation environment in a greenhouse located in Jeonju was monitored and internal environmental parameters were analyzed. Temperature, humidity, RAD, and PPF sensors were installed to monitor environmental conditions in the test greenhouse. Data were collected every 10 minutes during four winter months from sensors placed across the greenhouse to assess its permeability and environmental uniformity. Temperature and humidity inside the greenhouse were relatively uniform with negligible deviations among the center, south, and north; however, it was judged that further analysis of gradients of these parameters from the east to the west of the greenhouse would be needed. Both RAD (Total solar radiation) and PPF (Photosynthetic photon flux) had high values on the south and were low on the north and the reduction rate of these parameters was 54% and 61%, respectively, indicating that a significant amount of light could not be transmitted. This implied a significant decrease in the amount of light entering the greenhouse during winter. Therefore, it is concluded that environmental control devices and auxiliary lighting are needed to achieve uniform greenhouse environment for efficient strawberry cultivation.

• 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.

• The KIPS Transactions:PartD
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• v.8D no.4
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• pp.427-438
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• 2001

Recently, Environmental Control Devices of Green House for Protected Cultivation is composed of on/off-type Controller to control each device using timer in equipment of intensive Labor. In case of system, it is difficult to grasp condition of the greenhouse about errors when this system has defect of a hardware, and it operates in the remote place or at night. In this paper, we developed a system that capable of replacing the existing control method of on/off with display panel in the greenhouse, monitoring data aquisition and status in the greenhouse using client computer based on internet. Also this system can communicate with each local greenhouse, and send alarm message about error. And we constructed web server to manage efficient informations for environmental control and corps cultivation in the greenhouse.

• Korean Journal of Environmental Biology
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• v.39 no.1
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• pp.39-45
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• 2021

To establish the environmentally friendly biological control of two-spotted spider mites (TSSM), Tetranychus urticae, in exported strawberry greenhouses, the TSSM density reduction efficiency of chemical and biological control measures was compared in commercial, exported strawberry greenhouses. In the biological control greenhouse, only Phytoseiulus persimilis, a natural enemy of TSSM, was released, and the chemical control greenhouse was only sprayed with commercial chemical pesticides. The density of each developmental stage of TSSM was higher in the chemical control greenhouse than in the biological control greenhouse. The management costs were lower for the biological control greenhouse than the chemical control greenhouse. These results suggest that it is possible to effectively control TSSM using P. pesrsimilis in exported strawberry greenhouses.

• Korean Journal of Environmental Agriculture
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• v.42 no.3
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• pp.231-238
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• 2023

We analyzed the variations in the CO₂ concentration and temperature between a CO₂-enriched and control greenhouse. We cultivated Alstroemeria 'Hanhera' in the two greenhouses and assessed the growth parameters (stem length, stem thickness, and the number of flowers) and yield. The CO₂-enriched greenhouse had a CO₂ generator that produced CO₂ at rate of 0.36 kg/h and its windows were programmed to open when the temperature exceeded 20℃ and close when it dropped below 15℃. The control greenhouse had no additional CO₂ supplementation, and its windows were programmed to open when the temperature exceeded 20℃ and close at approximately 17:00. In the morning, CO₂ concentration remained above 500 ppm in the CO₂-enriched greenhouse, which was higher than that in the control greenhouse (approximately 370 ppm). The ventilation effect only through the side windows to reduce the temperature in both greenhouses did not appear dynamically. CO₂ supplementation promoted plant growth, resulting in a significant increase in plant yield of over 60% compared to that of the control greenhouse. Our findings suggest that elevated CO₂ concentration in the morning can significantly promote the growth and development of Alstroemeria during the winter.

• Journal of Biosystems Engineering
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• v.15 no.2
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• pp.134-142
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• 1990

This study was carried out for the development of greenhouse temperature control system by modifying an APPLE-II microcomputer attached with several interface systems. The interface systems are composed of 12 bit A/D converter, output port, multiplexer, time clock, etc. Under the operation of developed system, the greenhouse temperature was to be manipulated within the setting temperatures assumed to be appropriate for certain plant growth. The temperature control equimpents installed in the greenhouse are one-speed propeller type fan and two-phase electric heater, which are selectively started or stopped according to the control logic programmed in the control system. The results are summarized as follows : 1. The difference between two temperatures measured by the developed system and the self-recording thermometer calibrated with standard thermometer was less than $1^{\circ}C$. 2. When the temperature were measurd by 12 bit A/D converter and both electric heater and ventilation fan were controlled by developed ON/OFF logic, greenhouse temperature showed narrow fluctuation bands of less than $1^{\circ}C$ near the setting temperatures. 3. The temperature acquisition and control system developed in this study is expected to be applicable to environment control system such as greenhouse only by modifying the logic based on long term experimental data. 4. In order to reduce the measurement error and to increase the system control efficiency, it is recommended that continuous study should be carried out in the aspect of eliminating various systematic noises and improving the environmental control logic.