• KIEAE Journal
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• v.14 no.1
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• pp.75-81
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• 2014

This study aims at investigating the benefit of actively controlling humidity to improve thermal comfort and energy efficiency in climate zones other than hot-dry. For this research purpose, three thermal control strategies, which adopted different initiative degrees in humidity control, were developed - i) temperature controls, ii) temperature and humidity controls, and iii) thermal sensation controls. Performance of the developed strategies were experimentally tested in a full scale mock up of an office environment. The study revealed that air temperature was better controlled in the occupied zone under the first two strategies than the thermal sensation based strategy. On the other hand, the thermal sensation-based strategy maintained thermal sensation levels more comfortably. In addition, energy consumption was significantly reduced when humidity was actively controlled for thermal comfort. The thermal sensation-based control strategy consumed significantly less electricity than the first two strategies. From these findings, this study indicated that adoption of an active humidity control system based on thermal sensation can provide increased thermal comfort as well as energy savings for summer seasons in climatic zones other than hot-dry.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.29 no.7 s.238
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• pp.868-877
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• 2005

We performed the experimental and the numerical study on the comparison of thermal comfort performance indices for cooling loads in the lecture room for 4 cases: Fan coil unit(FCU) or 4-way cassette air-conditioner is respectively operated with the ventilation system or without. We measured the velocity, the temperature distribution and predicted mean vote(PMV) value in the lecture room for 4 different air-conditioning methods. Effective draft temperature(EDT) and PMV were investigated to analyze the characteristics of two thermal comfort indices in the lecture room and to compare their values each other. From the results we knew that there is the similarity between PMV values and EDTs when the room is air-conditioned for cooling loads. It turned out that definition of the control temperature is very important when the EDT is calculated. Finally EDT should not be used to predict the accurate thermal comfort in case that the temperature and humidity are suddenly varied and the zone affected by the solar and inner wall radiation.

• Journal of Korea Multimedia Society
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• v.23 no.2
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• pp.155-165
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• 2020

In this paper, we propose a smart thermostat temperature set-point control method based on machine learning and rule engine, which controls thermostat's temperature set-point so that it can achieve energy savings as much as possible without sacrifice of occupants' comfort while users' preference usage pattern is respected. First, the proposed method periodically mines data about how user likes for heating (winter)/cooling (summer) his or her home by learning his or her usage pattern of setting temperature set-point of the thermostat during the past several weeks. Then, from this learning, the proposed method establishes a weekly schedule about temperature setting. Next, by referring to thermal comfort chart by ASHRAE, it makes rules about how to adjust temperature set-points as much as low (winter) or high (summer) while the newly adjusted temperature set-point satisfies thermal comfort zone for predicted humidity. In order to make rules work on time or events, we adopt rule engine so that it can achieve energy savings properly without sacrifice of occupants' comfort. Through experiments, it is shown that the proposed smart thermostat temperature set-point control method can achieve better energy savings while keeping human comfort compared to other conventional thermostat.

• Journal of the Korean Society of Clothing and Textiles
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• v.19 no.1
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• pp.36-50
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• 1995

The purpose of this study was 1) to estimate the improvement of thermal storage/release and moisture transport properties of PEG-treated acrylic athletic socks and suggest the optimum add-on for PEG treatment, 2) to investigate wear performance of untreated cocks and two kinds of socks treated with PEG of minimum and optimum add-on respectively, and 3) to consider the effect of thermal storage/release and moisture transport properties of PEG- treated socks on the wear performance and the subjective comfort zone. Thermal activities of specimens treated by PDC were evaluated on a DSC by measuring the heat of fusion on heating and the heat of crystallization on cooling. Moisture regain, absorption speed, wickability, water retenti on value, and water-vapor permeability were measured. In the wear trials that the subjects performed a subsequent exercise protocol wearing three differently treated socks in a conditioned environment ($14\pm2^{\circ}C$, 65$\pm$2% R.H.), microclimate temperature and humidity, and subjective wear sensations including thermal sensation, wettedness, softness, fit, and overall comfort were obtained. PEC-treated specimens with more than 20% add-on showed thermal storage on heating and thermal release on cooling by a DSC and the heat contents of treated ones were generally proportional to the add-ons. Moisture transport properties were highly improved after PEG treatment and increased rapidly with increasing add-on. The tendencies were, however, relaxed above 50% add-on and the treated knits were much stiffer above that add-on. In the wear trials of untreated, PEG add-on 20%, and 50% acrylic socks, the changes of microclimate temperature of 50% socks were significantly less than that of 20% socks. PEG add-on 50% socks showed significantly less changes of microclimate humidity than other two kinds of socks. Three kinds of socks showed significant differences in overall comfort and add-on 50% socks were accepted more comfortable than other two kinds of socks. Comfort zone of foot was extended after PEG treatment on socks and it implied that the subjects wearing PEG- treated socks felt comfortable in wider ranges of microclimate temperature and humidity.

• Journal of the Korean Society for Railway
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• v.13 no.6
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• pp.589-594
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• 2010

Superimposition of horizontal and vertical curves may hamper the ride comfort and running stability of train and largely affect the maintenance costs. However, in many cases, it is not easy to make a track alignment plan because of the geographic conditions or undesirable environmental factors. In this paper, a comparative study on the effect of superimposition of vertical and horizontal curve on the ride comfort and optimum horizontal curve conditions was performed. That is, optimal cant and ride comfort analysis with and without a vertical curve superimposed on the horizontal curve were evaluated. Also the superimposition effect on ride comfort and alignment conditions in high speed zone were evaluated. From the analysis results, it was found that the ride comfort is similar to that at the only horizontal curves when applying the compensation cant for the superimposed site.

• Journal of the Optical Society of Korea
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• v.4 no.1
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• pp.58-61
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• 2000

Viewing zone shape and size perform a key role in creating viewing comfort for the viewer. The horizontal and vertical sizes of viewing zones, formed by a full color transmission type holographic screen with a stereoscopic image projection are investigated. The screens have been recorded as holograms of a narrow stripe shaped object with different width; to extend the vertical size of the viewing zone the holograms were exposed two times with the hologram shifting between exposures. The viewing zone parameters were measured as a function of the stripe width of the object and of the exit pupil size of projection optics for several holographic screens having the size of the 30 $\times$ 40 $\textrm{cm}^2$.

• 한국태양에너지학회:학술대회논문집
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• 2011.11a
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• pp.202-207
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• 2011

This study has measured indoor temperature and relative humidity and evaluated it for one year by selecting Chungnam's rural areas for improving indoor environment of rural housing in the circumstance that the environment of housing is poor due to deterioration of rural housing. As a result of its evaluation, the indoor temperature difference by household appeared to be more than $13^{\circ}C$, and it was measured that the indoor temperature was mostly low. A difference of more than 40% in case of relative humidity occurred, so the difference of the indoor environment by household was clear. In case of the thermal comfort zone, the number of households that are distributed to more than 50% of a thermal comfort criterion in the winter was only 3 households, rather than the summer.

• International Journal of Air-Conditioning and Refrigeration
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• v.8 no.1
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• pp.73-83
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• 2000

The purpose of this study is to analyze and characterize the correlation of the thermal comfort sensation with physiological responses for men in winter indoor environment. A number of experiments were conducted under twenty different environmental conditions with college male students. Clinical information on each participant was reported in terms of electrocardiogram (ECG), electroencephalogram (EEG) and self-centered evaluation. The comfort zone in winter is found, throughout the study, at Standard New Effective Temperature (SET$T^+$) of 25.2$^{\circ}C$, Predicted Mean Vote (PMV) between 0.27 and 0.62, and Thermal Sensation Vote (TSV) in the range of -0.76 and 0.36. The largest difference in skin temperature is measured at the calf area with respect to air temperature changes. Skin sensitivity to environment temperature is explained as calf, head, chest and abdomen in descending order. Change in heat rate is analyzed to be in parallel with that of SET$T^+$.

• Journal of the Korean housing association
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• v.14 no.3
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• pp.1-8
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• 2003

It is not sufficient to control the indoor thermal environment using only one or two parameters by itself as human response for the control of indoor thermal environment. So a proper environmental thermal index is required for the control of indoor thermal environment effectively. In this study, the physical environment was measured and analysed and the skin temperature of the subjects and their response were investigated to evaluate the optimum thermal comfort range for cooling season in an apartment house. As a result, the optimal temperature was 26.1$^{\circ}C$ and the temperature ranges which more than 80% responded as satisfactory were 24.1~28.$0^{\circ}C$, respectively. As the OT had most significant interrelation with the PMV, it is desirable to use the OT in evaluating the thermal environment during cooling. Also, the comfort range was concluded between OT 25.5~27.3$^{\circ}C$ by appointing the PMV of -0.5~0.5 as the optimum comfort condition. In addition, the Human responses were compared with calculated PMV, OT and MRT and the relationships are suggested in order to utilize to control indoor thermal environment.

• Proceeding of Spring/Autumn Annual Conference of KHA
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• 2008.04a
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• pp.281-284
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• 2008

The purposes of this study were to make clear the present condition of indoor thermal environment in apartment units and to analyze the relation of the living factors with indoor thermal elements. The field surveys consisted of measurements on physical elements and observations on living factors and interview on resident's subjective responses were carried out in 20 apartment units. The field surveys were carried out during the $January{\sim}March$ 2007. Measuring elements were air temperature, globe temperature, and relative humidity. As results, the averages of indoor temperature each houses were $21.2{\sim}27.2^{\circ}C$, the number of houses exceed the comfort zone were 4. The averages of globe temperature each houses were $21.3{\sim}27.5^{\circ}C$, 6 houses exceeded the comfort zone. The means of relative humidity were $19.5{\sim}58.8%$, relatively dry condition. The clothing value of residents were $0.39{\sim}0.89$ clo(average 0.68 clo). The average of thermal sensation ratings each room were $4.2{\sim}4.8$, 'neutral'$\sim$'slightly warm'. The results of regression analysis on relations of living factors with the thermal elements are as follow; ventilation time(outdoor air exchange), door opening time with balcony, and gas cooker use time had significant effect on indoor temperature.