• The Korean Journal of Community Living Science
• /
• v.21 no.4
• /
• pp.633-639
• /
• 2010

This study was carried out to compare human thermoregulatory responses and preferred air temperature by feet immersion between summer and winter in terms of thermal comfort. Five healthy female university students participated in the study as subjects. They experienced feet immersion at $40^{\circ}C$ of water in the climatic chamber of $24^{\circ}C$, 50%RH from 19:30 to 21:00 in the summer and winter, respectively. Rectal temperature gradually decreased and maintained $0.08^{\circ}C$ lower in winter than summer, while mean skin temperature changed $0.4^{\circ}C$ greater in winter than summer(p=0.00). Air temperature selected by each subject for their thermal comfort revealed $0.8^{\circ}C$ higher in summer than winter(p=0.06). The results obtained suggest an increase in human thermoregulation and be used as preliminary data to maintain optimal indoor temperature in summer and winter.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
• /
• v.10 no.3
• /
• pp.368-377
• /
• 1998

The purpose of this study was to examine theory about indoor thermal comfort-environment as well as to determine thermal sensation and physiological responses for men in summer indoor environment, under various air temperature and relative humidity, with male university students. Subjective Evaluation, Heart Rate(Electrocardiogram), Electroencephalogram(EEG) were examined. We found that comfort of people was achieved at SE $T^{*}$ 24.7$^{\circ}C$, -0.82＜PMV＜0.93, subject's clothing(0.41c1o)and the difference of skin temperature was found at the calf area as air temperature changes. At low SE $T^{*}$, heart rate was decreased and at high SE $T^{*}$, heart rate was increased but there was no change EEG(keeping $\alpha$-wave).wave).

• Journal of the Korean Society for Precision Engineering
• /
• v.30 no.4
• /
• pp.442-449
• /
• 2013

This study was to compare a domestic comfort shoes to the popular import(SAS$^{(R)}$) to gain a better understanding in biomechanical characteristics for shoe design for the elderly. For each shoe type, morphologic dimensions, shock absorption, and flexibility were assessed. From subjects(n = 20, $72.4{\pm}5.5$ years, $67.7{\pm}7.9$ kg), mean peak pressure(MPP) and contact area(CA) at the plantar surface were analyzed. The domestic shoes reflecting anatomic contour of the plantar surfaces of Asians resulted in wider CA(by 30.4 $cm^2$), higher shock absorption(by 2.4%) and stiffness(by 0.5 N/mm) than the import. With the domestic shoes, significantly less MPPs were found at the forefoot(by 42~49%) regions(p < .05) and higher CA was noted additionally at hallux and lessor toes(by 26~63%). More anatomically-contoured insole and favorable mechanical characteristics may help reduce the plantar pressures more effectively and more evenly, especially across the central forefoot and midfoot regions of the plantar surface, especially for the design of the comfort shoes for the elderly.

• Korean Journal of Agricultural Science
• /
• v.49 no.4
• /
• pp.983-993
• /
• 2022

The purpose of this study is to provide information on a forest healing environment using the analysis of nature volatile organic compounds (NVOCs) and thermal comfort in Chungnam National University Experimental Forest, with the aim of using the Experimental Forest as a healing environment for health promotion. We analyzed NVOCs and thermal comfort of Chungnam National University Experimental Forest measured on September 12^th, 2021. As a result of the NVOC analysis, a total of seven substances were detected, mainly including alpha pinene and beta pinene. The detection amount for each time period was highest at the time of sunset. The thermal comfort was analyzed by time-dependent changes and changes according to clothing and exercise amount. The results showed that the predicted mean vote of the experimental forest is within the range of 'slightly cool' and 'slightly warm' sensation, and thus a comfortable thermal environment could be controlled by the amount of clothing and activity. Based on the analysis, this study provides information on the healing environment of the experimental forest at Chungnam National University. It also indicates that the forest can be used as a health promotion and healing environment with thermal comfort by composing a physical activity program of appropriate intensity for each time period.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
• /
• v.7 no.2
• /
• pp.341-352
• /
• 1995

In this study, thermal parameters were measured and 213 occupants were also questioned in three office buildings located in Seoul during the summer season. Predicted mean vote-predicted percentage of dissatisfied(PMV-PPD) and standard new effective temperature(SET*) were used for evaluating Korean thermal sensation. The distribution of thermal sensation vote(TSV) and percentage of dissatisfied(PD) is very similar to that of PMV and PPD. By regression analysis, the following regression equation was obtained; TSV=0.339SET*-8.583. In this case, neutral temperature and comfort range are $25.3^{\circ}C$, $23.8{\sim}26.8^{\circ}C$ respectively. Present experimental results obtained from the field study is less sensitive to the temperature change than those obtained from the climate chamber study in Korea. But, thermal sensations are similar to each other near the neutral point. The neutral temperature and comfort range obtained by this experiment are higher than those of ANSI/ASHRAE Standard 55-1974 about $1.4{\sim}1.8^{\circ}C$.

• Journal of the Society of Naval Architects of Korea
• /
• v.42 no.4 s.142
• /
• pp.402-410
• /
• 2005

This paper focused on the analysis of the thermal comfort conditions in 1,000 ton class patrol ship's cabins through the evaluation of PMV(predicted mean vote) and PPD(predicted percentage of dissatisfied). Different areas have different clothing and activity in the ship. Therefore, any area may be thermally uncomfortable in case of air conditioning with equal temperature, relative humidity and relative air velocity. PMV or PPD-DCAC (demand controlled air conditioning) system is a new design that the whole cabins are maintainable with the ideal thermal comfort condition.

• Transactions of the Korean Society for Noise and Vibration Engineering
• /
• v.26 no.2
• /
• pp.210-216
• /
• 2016

In this work, performance analysis to improve ride comfort of an ER (electrorheological) fluid damper for a mid-sized passenger vehicle in terms of tire pressure is presented. An ER damper by considering specification for a mid-sized commercial passenger vehicle is proposed and mechanically designed. After manufacturing and assembling the proposed ER damper with design parameters, their performance such as field-dependent damping forces are experimentally measured. A quarter-vehicle ER ECS (Electronic Control Suspension) system consisting of the ER damper, sprung mass, spring, sky-hook controller and tire is constructed to analysis the ride comfort performances. Vertical tire stiffness with different tire pressure is experimentally measured and investigated. In addition, ride comfort analysis such as vertical acceleration root mean square (RMS) of sprung mass is investigated under bump road using quarter-vehicle test equipment.

• KIEAE Journal
• /
• v.16 no.1
• /
• pp.11-19
• /
• 2016

Purpose: PMV, PET, and similar thermal comfort indices and microclimate modeling have recently become actively used to evaluate thermal comfort. This study will look at pedestrian roads with diverse spatial characteristics on university campus using the ENVI-met model as the base for onsite measurement. Method: The PET was used as the thermal comfort index. The first microclimate measures were collected on September 20, 2014, and the second microclimate measures were collected on June 1, 2015. The ENVI-met model was used at the same time. Result: As a results, Onsite measurement results differed depending on the PET spatial characteristics. The location associated with the most discomfort had a PET of $47.8^{\circ}C$. The spatial characteristics of this place included a with no shade. The most comfortable location had shade, and the PET was $24.6^{\circ}C$. When the ENVI-met model and onsite measurements were compared, similar patterns were found, but with a few differences at specific points; this was due to the limitation of using input materials such as trees, buildings, and covering materials with the ENVI-met model. This factor must be thoroughly considered when analyzing modeling results.

• KIEAE Journal
• /
• v.10 no.4
• /
• pp.67-73
• /
• 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
• /
• v.10 no.6
• /
• pp.721-731
• /
• 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.