• Proceedings of the Korean Society for Agricultural Machinery Conference
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• 2000.11c
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• pp.676-683
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• 2000

For high quality storage of agricultural products, temperature, humidity and gas conditions in a storage house should be controlled properly. But most of the low temperature storage house is depending on temperature control. This study aimed to develop an automatic control system for low temperature storage house that can control storage conditions such as temperature, humidity and $CO_2$ gas concentration. The developed system alarms the user, by telephone or beeper, when abnormal condition has occurred. The farmer can also monitor the inside condition of warehouse in his residence, by Internet. From the results of the performance test, the temperature and relative humidity in the warehouse is controlled within the range of ${\pm}0.5^{circ}C$ and ${\pm}2%$, respectively.

• KIEAE Journal
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• v.11 no.2
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• pp.91-96
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• 2011

The purpose of this study is to measure the environmental effects of different alternative building materials. The following building materials were tested: clay bricks, cement wall, and red-clay plaster. Four mock-up models were constructed using clay bricks, cement wall, red-clay plaster and the last model as the control model. The effects of the above four building materials on temperature, humidity, the emissions of formaldehyde, and V.O.C were measured. This experiment was conducted during September. The conclusions are as follows. Clay bricks were able to control temperature, humidity and filter formaldehyde by itself. The environment within the cement wall was not affected by the humidity changes outside. Red-clay plaster walls had little impact on the environment because it is very thin.!

• Journal of Bio-Environment Control
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• v.29 no.3
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• pp.259-264
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• 2020

In this study, the humidity control effect of a counter-flow ventilator was analyzed in a greenhouse with high relative humidity at night in the winter season. A case of the counter-flow ventilator was 0.96 × 0.65× 0.82(W × D × H, m) and there were heat transfer element and two fans for air supply and exhaust in the counter-flow ventilator. Two counter-flow ventilators were used in this study and the setting humidity of the ventilators was 80%. The temperature and relative humidity at night(18:00-8:00) in the greenhouse were measured. In a greenhouse without a counter-flow ventilator, the average temperature and humidity was 14.9℃, 82.8%, respectively. When the counter-flow ventilator was operated, the corresponding averages were 15.1℃, 79.9%. The independent sample t test of monthly temperature and relative humidity showed no difference in temperature, and a significant difference in relative humidity with 1% of the significance level. Therefore, using the counter-flow ventilator helps to control relative humidity in greenhouse and increase yield.. And further research considering the pros and cons of using the counter-flow ventilator is needed.

• Journal of computational fluids engineering
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• v.21 no.2
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• pp.32-39
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• 2016

The Gradient Biome is a unique and large greenhouse(length 200 m, width 50 m, height:40 m) in which the elements of the weather, such as temperature and humidity, are controlled and reproduced in such a way as to create a continuous gradient from the tropical to frigid zones along specified longitudinal or transvers lines on the earth. One of the main purposes of the Gradient Biome is to observe the possible responses of the ecosystems (mainly plants), which are to be corresponding to each test climate and be introduced in the Biome, to the expected global warming. As one of the expected responses is the shift of the ecosystem(s) toward the region of suitable environment, there should be no artificial obstacles, which can prevent the shift, inside the facility. However, it is important but not so easy to find the ways of how the temperature and humidity in the Biome could be reproduced since the environmental variables tends to be homogeneous. In this paper, numerical simulations were carried out to find the effective control methods for air temperature and humidity inside the real scale Biome. One of the contributed solvers of OpenFOAM, which is an open source physics simulation code, was modified and used for the simulations.

• Proceedings of the SAREK Conference
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• 2007.11a
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• pp.322-327
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• 2007

Dedicated outdoor air-conditioning(DOA) system that utilizes pre-cooling and desiccant dehumidification can be superior to conventional cooling and reheating system with respect to energy consumption and indoor thermal comfort. In this work, simulation has been conducted to study various factors that affect the performance of DOA. Dynamic simulation shows the transient variation of temperature and humidity as the on/off control logic is imposed. Exit humidity of process air and flow rate are varied to study the effect on exit temperature of process air, dehumidification quantity, required regeneration temperature and exit humidity of regeneration air. For an outdoor air condition of $28.5^{\circ}C$ temperature, 16 g/kg humidity ratio and 2000 cmh flow rate, the dehumidification efficiency is increased by 4.6% as the flow rate is doubled.

• KIEAE Journal
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• v.10 no.6
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• pp.67-72
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• 2010

This study was conducted to examine the change of heating environment with the creation of an indoor water space. Living environments and comfort of dwellers can be improved by utilizing the physical properties of water effectively. This study focuses on the basic examination of the effect of water space and the environmental effects of water space by experiment. Two identical models were fabricated to compare the changes in indoor temperature and humidity with and without a water space. With the water space, temperature was reduced by an average of $0.55^{\circ}C$ a day and moisture content increased by an average of 4%. As a result, it was possible to obtain quantitative data on water space's temperature reduction and humidity control capacities. This study is expected to provide basic information for further studies on the effect of water spaces in various buildings.

• Journal of Sensor Science and Technology
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• v.30 no.4
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• pp.243-249
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• 2021

Humidity is an important physical quantity that is closely related with the quality of everyday life as well as the quality control of products in various industries. Here, we have developed a divided-flow type humidity generator of which humidity generation is faster than the saturator-based humidity generator in ppm level. The operation principle of the divided-flow humidity generator is first introduced. Then, the performance of the divided-flow humidity generator is verified by testing the radiosonde humidity sensor at low temperature. As a result, the humidity generated from the divided-flow humidity generator is consistent with the saturator-based precision humidity generator within 1.6% relative humidity in the range from 10% to 40% at -45 ℃. It is also found that the radiosonde humidity sensor shows measurement errors by 3% - 5% at -45 ℃ when it is only calibrated at room temperature. The response times of radiosonde humidity sensor using the divided-flow humidity generator are between about 2 and 9 minutes, whereas those by the saturator-based humidity generator are about 20 minutes. In this regard, the divided-flow humidity generator has a merit in terms of fast humidity changes for the calibration of radiosonde humidity sensors at low-temperatures.

• Journal of Conservation Science
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• v.38 no.1
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• pp.72-79
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• 2022

A paulownia wood has been widely used with various advantages as its low weight, permeability, convenient workability and aesthetic patterns for a long time. However, the related empirical researches and simultaneous evaluations of functionality are insufficient compared with acid-free archival boxes for now. In this study, the indoor and outdoor temperature and relative humidity control and heat release rate were evaluated under the controlled and uncontrolled circumstance in 2018. The paulownia wood storage box showed superior control effect of relative humidity than the acid-free archival box in constantly uncontrolled environment. Also, the possibility of the flame diffusion from the surface of the materials was higher for the paulownia materials, and the acid-free archival box showed more dangerous patterns in the early stages of the fire.

• Journal of Biosystems Engineering
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• v.25 no.3
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• pp.213-220
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• 2000

Grafting of fruit-bearing vegetables has been widely used to increase the resistance to soil-borne diseases, to increase the tolerance to low temperature or to soil salinity, to increase the plant vigor, and to extend the duration of economic harvest time. After grafting, it is important to control the environment around grafted seedlings for the robust joining of a scion and rootstock. Usually the shading materials and plastic films are used to keep the high relative humidity and low light intensity in greenhouse or tunnel. It is quite difficult to optimally control the environment for healing and acclimation of grafted seedlings under natural light. So the farmers or growers rely on their experience for the production of grafted seedling with high quality. If artificial light is used as a lighting source for graft-taking of grafted seedlings, the light intensity and photoperiod can be easily controlled. The purpose of this study was to develop a prototype system for the graft-taking enhancement of grafted seedlings using artificial lighting and to investigate the effect of air current speed on the distribution of air temperature and relative humidity in a graft-taking enhancement system. A prototype graft-taking system was consisted by polyurethane panels, air-conditioning unit, system controller and lighting unit. Three band fluorescent lamps (FL20SEX-D/18, Kumho Electric, Inc.) were used as a lighting source. Anemometer (Climomaster 6521, KANOMAX), T-type thermocouples and humidity sensors (CHS-UPS, TDK) were used to measure the air current speed, air temperature and relative humidity in a graft-taking system. In this system, air flow acted as a driving force for the diffusion of heat and water vapor. Air current speed, air temperature and relative humidity controlled by a programmable logic controller (UP750, Yokogawa Electric Co) and an inverter (MOSCON-G3, SAMSUNG) had an even distribution. Distribution of air temperature and relative humidity in a graft-taking enhancement system was fairly affected by air current speed. Air current speed higher than 0.1m/s was required to obtain the even distribution of environmental factors in this system. At low air current speed of 0.1m/s, the evapotranspiration rate of grafted seedlings would be suppressed and thus graft-taking would be enhanced. This system could be used to investigate the effects of air temperature, relative humidity, air current speed and light intensity on the evaportranspiration rate of grafted seedlings.

• Journal of the Korean housing association
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• v.17 no.2
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• pp.41-46
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• 2006

This study aims to analyzed thermal comfort characteristics and subject response for thermal environment of Korean traditional houses.. The air temperature and humidity in the living area of the residence were measured in during a day. And the subject response were surveyed to evaluate of controling the thermal environment factor (temperature, humidity, comfort) of the korean traditional houses. As a result, the variation of air temperature and humidity of most rooms are considerably static while condition of outdoors are much varied, it is showed that indoor climate has been controled with traditional soiled walls. And environmental control for the air temperature and humidity is estimated considerably satisfactory.