• Proceedings of the Korea Concrete Institute Conference
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• 2008.11a
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• pp.741-744
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• 2008

Quality control of early age concrete significantly influences the long term performance. Primary factors for early age concrete quality control should include the relative humidity and temperature variation, and these are more important as structures become massive and huge. Temperature raise due to cement hydration causes stress, which can develop to cracking with internal and/or external restraints. Exposure conditions including ambient temperature, humidity and wind also significantly affect the cracking behavior of early age concrete. Among many of studies on the early age concrete behavior, investigation on the variation of temperature and relative humidity internal of concrete is not common. That is in part because the difficulties in measuring the relative humidity and temperature inside the concrete. This study used a digital sensor with an appropriate logger to measure internal temperature and relative humidity. This direct measuring method is expected to provide more reliable and comprehensive data acquisition on the early age behavior of concrete.

• Journal of Biosystems Engineering
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• v.36 no.4
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• pp.279-284
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• 2011

Protected vegetable production area is greater than 26% of the total vegetable production area in Korea, and portion of protected production area is increasing for flowers and fruits. To secure stable productivity and profitability, continuous and intensive monitoring and control of protected crop production environment is critical, which is labor- and time-consuming. Failure to maintain proper environmental conditions (e.g., light, temperature, humidity) leads to significant damage to crop growth and quality, therefore farmers should visit or be present close to the production area. To overcome these problems, application of remote monitoring and control of crop production environment has been increasing. Wireless monitoring and control systems have used CDMA, internet, and smart phone communications. Levels of technology adoption are different for farmers' needs for their cropping systems. In this paper, potential of wireless remote monitoring of protected agricultural environment using CDMA SMS text messages was reported. Monitoring variables were outside weather (precipitation, wind direction and velocity, temperature, and humidity), inside ambient condition (temperature, humidity, $CO_2$ level, and light intensity), irrigation status (irrigation flow rate and pressure), and soil condition (volumetric water content and matric potential). Scenarios and data formats for environment monitoring were devised, tested, and compared. Results of this study would provide useful information for adoption of wireless remote monitoring techniques by farmers.

• The Journal of the Korea institute of electronic communication sciences
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• v.17 no.4
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• pp.729-738
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• 2022

Existing wardrobes have been used only for storing simple clothes. Since it has a function to store clothes, there is only one way to control the environment such as humidity or temperature, and there is only one way to purchase and store items such as a desiccant. In this paper, by increasing the convenience in the existing wardrobe, automatic temperature and humidity control and various convenient functions were added. In line with the smart home market and smart phone application market that have grown over the past several years, along with the development of a wardrobe with sensors, the temperature and humidity control function and other functions inside the wardrobe through Bluetooth pairing between the wardrobe and the smartphone can be customized to the user using a smartphone. Through the clothing selection function and the weather data in the application, we want to implement convenient functions such as the function of recommending clothes in the closet to match the weather.

• Proceedings of the IEEK Conference
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• 2002.07b
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• pp.841-843
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• 2002

In this paper, we develop the remote control device of vending machine through internet. This device can control the temperature, humidity and on/off switch. This device is operated by the Java based TCP/IP control program.

• Journal of the Korean Society of Clothing and Textiles
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• v.32 no.7
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• pp.1129-1136
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• 2008

The gaiter is one of the personal protective equipments worn in various industrial sites. This study was performed on humans to investigate the physiological strain of wearing gaiters and to compare control gaiters that are currently on the market and new gaiters that are developed for alleviating heat stress. Experiments were conducted in a climatic chamber of WBGT $30.0\pm0.7^{\circ}C$ under five differed experimental conditions: None, Control A, Control B, New A, New B. The results were as follows. The temperature inside gaiters was significantly lower in both New A and New B than in both Control A and Control B and the difference between news and controls was 1$^{\circ}C$ (p<.01). The humidity inside gaiters in both New A and New B were higher than that in Control A, and lower than that in Control B (p<.01). The outermost surface temperature of the gaiter was the lowest in None and it increased in the following order: New B < New A < Control A < Control B. Mean skin temperature was higher by 0.14$^{\circ}C$ in wearing gaiters than in no gaiters. Skin temperatures in lower body were lower in Control than in New and skin temperature in upper body were higher in Control than in New (p<.01). Local sweat rate, total weight loss and subjective sensations did not show a significant difference according to the gaiters. It was concluded that wearing gaiters affected distribution of skin temperature and local sweat rate.

• Journal of the Korean Society of Radiology
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• v.14 no.1
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• pp.15-22
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• 2020

PET(Positron Emission Tomography) devices are used as PET/CT or PET/MRI devices fused with the devices of CT or MRI for obtaining anatomical information. Therefore, the devices are constructed in circular ring-type structure whose length of gantry(the main part of filming) becomes wider and the interior depth becomes longer in comparison to other common medical equipments. scintillator, one of the components in PET devices, is inside the gantry, and as it is consisted of crystal which is sensitive to the change of temperature and humidity, large temperature change can cause the scintillator to be damaged. Though scintillator located inside the gantry maintains temperature and humidity with a thermo-hygrostat, changes in temperature and humidity are expected due to structural reasons. The output value was measured by dividing the inside of the gantry of the PET/CT device into six zones, each of which an Adafruit BME 280 temperature and humidity sensor was placed at. A thermo-hygrostat keeps the temperature and humidity constant in the PET/CT room. As the measured value of temperature and humidity of the sensor was obtained, the measured value of temperature and humidity appeared in the thermohygrostat was taken at the same time. Comparing the average measured values of temperature and humidity measured at each six zones with the average values of the thermo-hygrostat results in a difference of 2.71℃ in temperature and 21.5% in humidity. The measured temperature and humidity of PET Gantry is out of domestic quality control range. According to the results of the study, if there is continuous change in temperature and humidity in the future, the aging of the scintillator mounted in the PET Gantry is expected to be aging, so it is necessary to find a way to properly maintain the temperature and humidity inside the Gantry structure.

• Journal of Biosystems Engineering
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• v.43 no.4
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• pp.342-351
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• 2018

Purpose: Recently, an increasing number of farms have been cultivating shiitake mushrooms using a sawdust substrate and a cooler/heater. In this study, an attempt was made to develop an environmental control system using a heat pump for cultivating high-quality shiitake mushrooms. Methods: An environmental control system, consisting of an air-to-water type heat pump, a thermal storage tank, and a radiator in a variable opening chamber, was designed and fabricated. The system was also installed in the cultivation facility of a farm cultivating shiitake mushrooms so as to compare the proposed control system with a conventional environmental control system using a cooler-condensing unit and an electric hot water boiler. Results: The uniformity of the environment was analyzed through environment measurements taken at several positions inside the cultivation facility. It was determined that the developed environmental control system is able to control the variations in temperature and relative humidity to within 1% and 3%, respectively. In addition, a maximum temperature difference of $30^{\circ}C$ (maximum of $35^{\circ}C$, minimum of $5^{\circ}C$) and a maximum relative humidity difference of 30% (maximum of 90%, minimum of 60%) can be attained within 30 min inside the cultivation facility through the cooling of the heat pump and heating of the radiator in a variable opening chamber. Thus, the developed control system can be used to cultivate high-quality shiitake mushrooms more effectively than a conventional cooler and heater. Conclusions: In comparison with a conventional environmental control system, the developed system decreased the yield of ordinary mushrooms by 65%, and increased that of high-quality mushrooms by 217%. This corresponds to a 16% increase in gross farm income. Consequently, the developed system is expected to improve the income of shiitake mushroom cultivating farms.

• Proceedings of the Korean Society for Agricultural Machinery Conference
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• 2017.04a
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• pp.135-135
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• 2017

Greenhouse have been developed to provide the plants with good environmental conditions for cultivation crop, two major factors of which are the inside air temperature and humidity. The inside temperature are influenced by the heating systems, ventilators and for systems among others, which in turn are geverned by some type of controller. Likewise, humidity environment is the result of complex mass exchanges between the inside air and the several elements of the greenhouse and the outside boundaries. Most of the existing models are based on the energy balance method and heat balance equation for modelling the heat and mass fluxes and generating dynamic elements. However, greenhouse are classified as complex system, and need to make a sophisticated modeling. Furthermore, there is a difficulty in using classical control methods for complex process system due to the process are non linear and multi-output(MIMO) systems. In order to predict the time evolution of conditions in certain greenhouse as a function, we present here to use of recurrent neural networks(RNN) which has been used to implement the direct dynamics of the inside temperature and inside humidity of greenhouse. For the training, we used algorithm of a backpropagation Through Time (BPTT). Because the environmental parameters are shared by all time steps in the network, the gradient at each output depends not only on the calculations of the current time step, but also the previous time steps. The training data was emulated to 13 input variables during March 1 to 7, and the model was tested with database file of March 8. The RMSE of results of the temperature modeling was $0.976^{\circ}C$, and the RMSE of humidity simulation was 4.11%, which will be given to prove the performance of RNN in prediction of the greenhouse environment.

• Membrane Journal
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• v.20 no.1
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• pp.76-86
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• 2010

This study investigated the effect of 2-butoxyethanol (BE) as a nonsolvent additive, relative humidity and air contact time on the structure formation of microfiltration membranes, permeation and morphology properties in phase inversion process. The membranes were prepared by using polyethersulfone (PES)/Dimethyl formamide (DMF)/p-toluenesulfonic acid (TSA)/Polyvinylpyrrolidone (PVP)/BE casting solution and water coagulant. Casting solutions containing various concentration of BE were exposed to a water vapor, under 60 and 80% of relative humidity for 40 and 90 sec, which would be absorbed on. The correlations between the membrane permeation properties and surface/inner structures of membrane were investigated. The characterization of membranes was carried out by a capillary flow porometer, a FE-SEM and a water permeation test apparatus. The surface structure of PES membranes was affected by the exposure time as well as the relative humidity strongly. Furthermore, the addition of BE helped control surface and inner structure at certain humidity and exposure time.

• The Journal of the Korea institute of electronic communication sciences
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• v.12 no.4
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• pp.645-650
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• 2017

It is a system that controls temperature, humidity and fine-dust to make interior environment more comfortable for modern people who spend 90% of the time in indoor. In an experiment of finding which one of temperature and humidity influence more to discomfort index, for a fixed temperature of 21, discomfort index increased by 0.1 with a 1 change of humidity, and for a fixed humidity of 40, discomfort index increased by 1.2 with a 1 change of temperature. As a result, it was found that the temperature is more influential than the humidity to discomfort index. In an experiment of measuring communicational limitation of Bluetooth, the communication was possible for at most 30 meters without obstacles. With high obstacles like walls or steel bars, it was able to penetrate at most 2 obstacles and maximum distance which it can communicate was 10 meters for just one high molecule obstacle.