• Fashion & Textile Research Journal
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• v.11 no.6
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• pp.947-952
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• 2009

The purpose of this study is to analyze skin wettedness($w$) used as the rate index of thermal comfort, and to evaluate the wear comfort of outdoorwear. Skin wettedness is widely used to express the degree of thermal comfort. If skin wettedness exceeds a certain threshold, the body feels damp and discomfort. An experiment which consisted of rest(30 min), exercise(30 min) and recovery(20 min) periods was administered in a climate chamber with 10 healthy male participants. Two kinds of outdoorwears made of 100% cotton fabrics (Control) and specially engineered fabrics having feature of quick sweat absorbency and high speed drying fabric (Functional) were evaluated in the experiment. The condition of climate chamber was controlled according to the thermal insulation of 4 kinds of experimental ensembles(E1~E4). Total sweat loss, sweat loss absorbed into clothing and skin temperature were measured. Skin wettedness was calculated from the ratio of evaporative rate to the maximal evaporative capacity. Skin wettedness of 'Functional' was lower than 'Control' in the 3 kinds of ensembles(E1, E2, E4) because the materials of 'Functional' were composed of quick sweat absorbency and high speed drying fabrics, water vapour permeability and waterproof fabrics.

• KIEAE Journal
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• v.10 no.4
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• pp.67-73
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• 2010

As more and more people desire to live in an apartment complex with a comfortable outdoor space, many construction company became interested in outdoor design. In order to increase the use of outdoor space and create the most pleasant environment, outdoor thermal environment and comfort should be evaluated quantitatively from the design stage. This study utilized ENVI-met 3.1 model to analyze outdoor thermal environment in apartment complex, and evaluated outdoor thermal comfort in 6 points of apartment complex. The physiologically equivalent temperature(PET) was employed as a outdoor thermal index. Playground B had a poor thermal environment with the maximum PET $43^{\circ}C$ (Very hot). Because shading by building and tree didn't affect outdoor thermal environment of playground B. To design comfortable outdoor space from the view point of thermal environment, the factors influencing Mean radiant temperature(MRT) and wind speed should be considered in design stage. Since it is difficult to control outdoor thermal environment compared with indoor environment, we should take into account an assessment for outdoor thermal environment and comfort in outdoor design stage.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.10 no.6
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• pp.721-731
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• 1998

Recently, many researchers are studying the relation between thermal environment and human comfort. The purpose of this study was to obtain basic data which are necessary to determine the thermal comfort sensation and physiological responses for men in winter indoor environment. From January to February 1998, subject experiment was 40 times proceeded under twenty different conditions of air temperature and relative humidity with early-twenty male university students. We examined subjective evaluation, Electrocardiogram(ECG), Electroencephalogram(EEG) of subjects. The results of this study can be summarized as follows : The comfort zone of people in winter was achieved at Standard new effective temperature($SET^*$) $ 25.2^{\circ}C$, PMV range was obtained by Fanger's statistical calculation was －0.27＜PMV＜＋0.62, TSV range obtained subjects vote was －0.76＜TSV＜＋0.36. The largest difference of skin temperature was found at the calf area as air temperature changes. vote rate of human body presented calflongrightarrowheadlongrightarrowforearmlongrightarrowchestlongrightarrowabdo men in turn. Heart rate was decreased at low $SET^*$ and heart rate was increased at high $SET^*$ But there was no change at EEG.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.23 no.5
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• pp.463-471
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• 2013

This paper presents design and control of electronic control suspension(ECS) equipped with controllable magnetorheological(MR) damper for passenger vehicle. In order to achieve this goal, a cylindrical type MR fluid damper that satisfies design specification of a middle-sized commercial passenger vehicle is proposed. After manufacturing the MR damper with design parameters, their field-dependent damping forces are experimentally evaluated and compared with those of a conventional damper. A quarter-vehicle MR ECS system consisting of sprung mass, spring, tire, controller and the MR damper is established in order to investigate the ride comfort performances. On the basis of the governing equation of motion of the suspension system, five control strategies(soft, hard, comfort, sport and optimal mode) are formulated. The proposed control strategies are then experimentally realized with the quarter-vehicle MR ECS system. Control performances such as vertical acceleration of the car body and tire deflection are evaluated in frequency domains on random road condition. In addition, performance comparison of WRMS(weighted root mean square) of the quarter-vehicle MR ECS system on random road are undertaken in order to investigate ride comfort characteristics.

• Journal of the Ergonomics Society of Korea
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• v.32 no.4
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• pp.381-387
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• 2013

Objective: This paper studies the method of measuring whole-body vibration in the car and terms associated. Background: Human exposure to vibration can be broadly classified as localized and whole-body vibration. The whole-body vibration affects the entire body of the exposed person. It is mainly transmitted through the seat surfaces, backrests, and through the floor to an individual sitting in the vehicle. It can affect the comfort, performance, and health of individuals. Method: Human responses to whole-body vibration can be evaluated by two main standards such as ISO 2631 and BS 6841. The vibration is measured at 8 axes - three translations at feet, 3 translations of hip and two translations of back proposed by Griffin. B&K's sensors used in this study are the 3-axes translational acceleration sensor to measure the translational accelerations at the hip, back and foot. Results: The parameters associated with the whole-body vibration in the car are frequency weightings, frequency weighted root-mean-square, vibration dose values, maximum transient vibration value, seat effective amplitude transmissibility, ride values and ride comfort. Conclusion: Studied the evaluating methods of vibration exposure and ride comfort. Application: Evaluation of whole-body vibration in the car.

• Journal of the Korean Society of Clothing and Textiles
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• v.37 no.8
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• pp.1095-1106
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• 2013

This study evaluated the wear comfort properties of water-vapor-permeable (WVP) garments using a movable sweating thermal manikin. Manikin tests were performed in a climatic chamber (temperature T=20, $35{\pm}0.5^{\circ}C$ and relative humidity $H=50{\pm}10%$) using seven sportswear outfits (a long sleeve shirts and a long pants) made with seven different WVP fabrics. Physiological responses of wear trials could be correlated with measurement parameters of the thermal manikin experiment; subsequently, a regression model that represented a final comfort sensation could be obtained. The regression model developed in this work is based on thermal manikin measurements; consequently, it provides an independent comfort sensation level in a relatively short time at a low cost while maintaining the reproducibility of results. It translates into more actual choices for sportswear manufacturers and sportswear consumers.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.28 no.6
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• pp.217-223
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• 2016

In this study, we investigated the operating method of a driver for an air conditioning system according to the temperature difference between the indoor and outdoor environments of a car parked outside during the summer. Researchers of this study suggest the comfort mode of a car air conditioner to improve the thermal comfort of the driver, thereby maintaining longer comfort. This study separately, analyzed temperatures on a cloudy day and sunny day. The results showed the car indoor heat environment and physiological results (EEG, ECG) of the subject. It showed a difference of the car indoor heat environment by weather with the difference also appearing in the physiological response of the subject. In conclusion, in this paper, on the basis of the physiological response of a subject, a comfortable algorithm of automobile air conditioner is being suggested.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.16 no.3
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• pp.303-309
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• 2004

In order to improve thermal comfort in the Rotunda, which is high and wide visiting space of the new national museum of Korea, eight ventilating fans were installed near the ceiling of Rotunda. It has been analyzed thermal comfort of Rotunda with/without ventilating fans by numerical simulation. To evaluate thermal comfort of the Rotunda, well-known indices, PMV and PPD were introduced. The results of present investigation show that temperature distribution of the case with fans is closer to target temperature than the case with-out fans at the breathing zone. In the case without fans, thermal stratification with 16$^{\circ}C$ of temperature difference occurs along the height of the Rotunda which makes the thermal environment worse and the PPD values reach up to 50% in the 6th floor connection passage. In the case with fans, however, the vertical temperature difference were reduced to 9$^{\circ}C$ and the PPD values were lower below 20%. Consequently, the ventilating fans adopted on this study are effectively used for improving the thermal comfort in large space structure with thermal stratification.

• Journal of the Korean Society of Radiology
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• v.16 no.7
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• pp.889-896
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• 2022

This study attempted to evaluate the usefulness of the air mattress by analyzing the subjective comfort of the patient due to the application of the air mattress to the table of computed tomography through a questionnaire and analyzing the change in image quality through quantitative and qualitative evaluation of the patient's clinical images. The subjects who participated in the study were 221 men and 229 women, and the age range was from 18 to 86. To evaluate the change in image quality, a total of 150 patients, 50 patients per group, were selected for quantitative evaluation, and 20 patients per group, a total of 60 patients were selected for qualitative evaluation. As a result of this study, the subjective comfort of patients increased due to air mattresses, and there was no difference in image quality as a result of quantitative and qualitative evaluation of clinical images. From the above results, it is believed that the air mattress can be usefully applied in a way that can increase the subjective comfort of the patient without any harm to the diagnostic image.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.22 no.3
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• pp.214-222
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• 2012

Driver's feeling is variously affected by lots of components such as engine, frame, wheels, and seats during the operation of automobiles. The main objective of this research is to identify the correlation between subjective evaluation and vibration metrics that was set by ISO to investigate development of the car vibration quality index using multiple linear regressions(MLR). A previous research related with automotive vibration quality used the method of calculating acceleration values of the point of a seat, a seat back, foot as RMS for objective evaluation. The automotive comfort is determined by RMS values. In comparison with the previous research, this study includes not only the vibration metrics, but also subjective values by jury evaluation. By indentifying the correlation between subjective evaluation and vibration metrics, the automotive vibration quality index is developed through MLR. Based on the results of this study, the proposed the automotive vibration quality index which developed through MLR will be helpful to obtain objective and reliable automotive comfort values.