• The International Journal of Costume Culture
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• v.3 no.1
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• pp.30-40
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• 2000

The purpose of this research was to device thermal comfort model for radiation power plant workers in protective clothing. Three fabrics commonly used in protective workwear were made into coveralls of identical design and were evaluated by adult healthy males in four simulated work environment. It was investigated between the physiological response and subjects comfort according to environmental variance and clothing types. The of simulated work enviro mensent was controlled under four different humidity and temperature of each type. (Temperature 20±1℃, RH 40∼70%±5%, Temperature 30±1℃, RH 40∼70%±5%) An index of physiological response was connected with the thermal comfort designed. Mean skin temperature, skim temperature, Axillasy temperature ear canal temperature, clothing climate, total sweat, blood pressure, and R-R interval were be evaluated. Skin temperature difference ocurring during exercise and rest were significant only with respect to time and regions of the body, This despite physical differences in the three coveralls, particulary mass statistically experiment. Also, an index of subject wearing sensation was designed for thermal comfort after investigation determined the kind of clothes and the type of environment. As a result of this research, two types of multiple regressions was deviced to estimate thermal comfort of the protective clothing.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.15 no.2
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• pp.57-65
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• 2016

The suspension system of a subway vehicle is composed of $1^{st}$ and $2^{nd}$ springs. The suspension system is the most important parameter in determining the vibration ride comfort. If the $1^{st}$ suspension spring is designed as a spring with strong stiffness to improve the running stability at high speed, it causes vehicle vibrations. In this paper, by testing and analyzing changes of the characteristics of Chevron springs, which have been the primary suspension springs used for about 20 years, we study how changing the characteristics affects vehicle acceleration and ride comfort. The lateral and longitudinal vibrational ride comfort index levels were lower than the vertical ones. Therefore, as increasing the stiffness of Chevron springs has the greatest effect on the vertical vibrational ride comfort index level, a countermeasure for vertical vibration reduction is needed when the stiffness increases owing to aging. Finally, maintenance guidelines, including the replacement time for the Chevron rubber, were proposed based on these findings.

• 유체기계공업학회:학술대회논문집
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• 2006.08a
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• pp.105-108
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• 2006

should be in This paper presents review on human comfort criteria in major codes and standards for tall buildings. In general, human comfort criteria of tall buildings have been used by magnitude of wind-induced acceleration response. Two different indexes in determination of the magnitude have been used: the peak value which occurs during a period of time and the rms value averaged over this same period. These distinctive acceleration indexes are discussed in detail and each criterium was reviewed and compared. The distinctions arisen because of the different wave forms, or acceleration signatures were addressed. It is described that which index of acceleration should be adopted in establishment of Korean human comfort criteria. In addition, some arguments from a technical standpoint that favor the use of each index are presented.

• Proceedings of the KSR Conference
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• 2000.11a
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• pp.250-257
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• 2000

The speed-up of conventional trains is considered as one of the efficient methods to relieve traffic jam and to increase the capacity of transportation. In this study, we measured and analyzed the ride comfort of a push-pull Saemaeul Train with speed-up of 5km/h in curves and 10km/h on straight tracks as compared with present operation speed of the push-pull Saemaeul Trains. Four main lines-Honam, Kyungboo, Janghang, Kyungjeon- were chosen as representative lines for speed-up feasibility study. The increase of mean ride comfort index in case of speed-up is 0.5-2㏈. The mean ride comfort index of vertical direction in case of speed-up is 107-110㏈ for Honam line, 104-112㏈ for Kyungboo line, 108-112㏈ for Janghang line and 105-108㏈ for Kyungjeon line, which are rather high as compared with German trains of similar grade with maximum vehicle speed of 160km/h.

• Proceedings of the KSR Conference
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• 1998.11a
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• pp.405-412
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• 1998

Recently“ride comfort”problem becomes increasingly important because of today's needs for train speedup The concept of term “riding comfort” is equivocal. Generally it is defined as the vehicle vibration. There are many studies on evaluation method of ride comfort for railway. But each of then recommends the different assessment method and the different guidance. So users must review whether they can apply it to their system or not. In this paper, we discuss the evaluation methods defined in the standards - ISO 2631, UIC 513 R, CEN DRAFT prENV 12299 and the ride index suggested by Sperling.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2001.11a
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• pp.450-454
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• 2001

The aim of the study is to develope an objective index for the evaluation of vehicle ride comfort using the measured vehicle accelerations. The equation of the index was derived from the correlation analysis of subjective ratings on selected vehicles and the reduced measure of the vehicle motions. First whole procedure of from the measurements to the calculation of the perceptual vibration was developed. Test condition of both the vehicle speed and the road condition was selected so as to maximize the reliability of the index. This paper suggested the equation of the objective ride index on vibration harshness, of which expected error is about 0.3 in 10 scale of subjective rating at 95％ of the significance level.

• Animal Bioscience
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• v.37 no.1
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• pp.142-150
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• 2024

Objective: This study was conducted to assess effects of heat stress on growth performance, physiological parameters, and blood profiles of Hanwoo steers during early-fattening period in climate chambers. Methods: Four Hanwoo steers (body weight, 454.3±10.9 kg; age, 14±0.1 month) were allocated into four levels of temperature-humidity index (THI) in a 4×4 Latin square design for 21 days (pre-adaptation, 7 d; heat stress, 7 d; post-adaptation, 7 d) per period. Experimental treatments were assigned according to THI chart based on National Institute Animal Science (NIAS, 2022): Comfort (25.5℃ to 26.5℃, 60%; THI 73 to 75), Mild (28℃ to 29℃, 60%; THI 77 to 79), Moderate (29.5℃ to 30.5℃, 80%; THI 82 to 84), and Severe (31℃ to 32℃, 80%; THI 85 to 86) in separate climatic controlled chambers. Results: The dry matter intake (DMI) of the formula feed was lower in Severe compared to Mild and Comfort (p<0.05). The DMI of rice straw was the lowest in Severe and lower in Moderate than Comfort and Mild (p<0.05). Both average daily gain and feed conversion ratio of Severe and Moderate were lower than those of Mild and Comfort (p<0.05). Water intake was the highest in Severe and lower in Moderate compared with Comfort and Mild (p<0.05). Heart rate and rectal temperature increased as THI level increased (p<0.05). Glucose was the lowest in Severe and lower in Moderate compared to Comfort (p<0.05). On the contrary, non-esterified fatty acid was the highest in Severe and lower in Moderate compared with Comfort (p<0.05). Blood urea nitrogen of Moderate and Severe were higher than those of Comfort and Mild (p<0.05). Cortisol increased as THI increased (p<0.05). Conclusion: This study demonstrated the negative effects of heat stress on the performance and physiological responses of Hanwoo steers during the early-fattening period. In addition, it is judged that the THI chart for Hanwoo steers of National Institute of Animal Science (2022) was properly calculated.

• Journal of Environmental Science International
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• v.27 no.12
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• pp.1261-1269
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• 2018

The purpose of this study was to investigate changes in the external thermal environment, following the application of evaporative cooling systems in buildings, in response to climate change. In order to verify changes in the external thermal environment, a T-test was performed on the microclimate, Thermal Comfort Index (TCI), and building surface temperature. Differences in microclimate, following the application of the evaporative cooling system in the building, were significant in terms of temperature and relative humidity. In particular, temperature decreased by more than 7% when the evaporative cooling system was applied. According to the results of the Thermal Comfort Index analysis, the Wet-Bulb Globe Temperature (WBGT) was below the limit of outdoor activities, indicating that outdoor activities were possible. The Universal Thermal Climate Index (UTCI) values were within the very strong heat stress range when the evaporative cooling system was not applied, When the system was applied, the UTCI values were within the strong heat stress range, indicating that they were lowered by one level. The building surface temperature decreased by ~10% or more when the evaporative cooling system was applied, compared to when it was not applied. Finally, the outside surface temperature of the building decreased by ~12% or more when the system was applied, compared to when it was not applied. We conclude that the energy saving effect of the building was significant.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.13 no.7
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• pp.647-652
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• 2001

The thermal comfort of indoor spaces is very important factor in our life. Regions, cultures, climates and individual difference for establishing thermally comfortable environments should be considered carefully because these factors have a large influence on the thermal comfort doing some complicated interactions with environmental, psychological and physical elements. Recently, predicted mean vote(PMV) based on the heat transfer theory between environmental factors and human bodies has evaluated by many researchers and widely used nowadays. The objective of this study is to evaluate the thermal comfort in workspaces with personal air conditioning system using the measurements of environmental comfort parameters and the questionnaire survey of occupant's thermal senses with response to the environment.

• Proceedings of the KSR Conference
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• 2003.10a
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• pp.167-174
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• 2003

Recently, the "ride comfort" problem becomes increasingly important because of today′s needs for train speedup. The concept of term "ride comfort" is equivocal. Generally it is defined as the vehicle vibration. There are many studies on evaluation method of ride comfort for railway. But each of them recommends the different assessment method and the different guidance. So users must review whether they can apply it to their system or not. In general, the evaluation methods defined in the standards - ISO 2631, UIC 513 R, and Ride Index suggested by Sporting - have been used in the railroad. The ride comfort measuring system according to the previous mentioned evaluation methods "ride comfort" has developed, verified and utilized in the railways.