In this paper, repeated compression-recovery behaviours of cylindrical fiber assemblies made of cupra fibers, and polyester fibers with heteromorphic and round sections are investigated experimentally with regard to sleeping comfort. The results are obtained as follows. (1) The same tendency in repeated compression-recovery behaviour is observed for three samples. The features of fiber type are recognized within sixth cycles, and after sixth cycles, the curves become converged to the same curve. (2) For compression displacement, three samples show different level of displacement under the condition that solidity is 0.0125 and maximum compression stress is 1176 Pa. The displacement of cupra fiber is the largest, and that of polyester fiber with heteromorphic section follows, and that of polyester fiber with round section is the smallest. (3) For WC, compression energy in compression process, the behavior has the same tendency as that of compression displacement. In contrast, the behavior of WC&prime, compression energy in recovery process is different from that of compression process. (4) The compression-recovery curve at sixth cycle under the condition that solidity is 0.0125 and maximum compression stress is 1176 Pa is analyzed using linearizing method. The relation between the logarithm of compression stress(Pc) and the logarithm of compression displacement(T) is linear. Empirical equation, Pc=ATⁿ is obtained, where A and n are constant parameters depending on material properties, measurement condition and compression stress.

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In this paper, the compressive stress relaxation properties of cylindrical fiber assembly made of polyester fibers with heteromorphic section, polyester fibers with round section and cupro-ammonium rayon fibers are investigated experimentally with regard to sleeping comfort. The results are obtained as follows.
(1) Experimental curve of SY, residual stress ratio is expressed by following empirical equation.
S_Y = σ/σ₀ = K(a₀ - ln t )
where, σ: stress at time t (Pa), σ₀ : initial stress (Pa), t: time(s), K(n.d.) and a₀(n.d.) : constants determined by fiber type and measurement condition. The results indicate that compressive stress relaxation phenomena of synthetic and regenerated fiber assembly show non-linear visco-elastic behaviour.
(2) Residual stress ratio at a certain time t of polyester fibers with w-shaped heteromorphic section and with round section has minimum value at 0.0179 in volume fraction, and that of cupra fiber is minimized at 0.0208 in volume fraction. The results indicate that the above conditions must be avoided in order to prevent large reduction of fiber volume in terms of preservation.
(3) Compression stress relaxation phenomena of cupra staple fiber assembly is expressed by following equation derived from non-linear two element visco-elastic model.
S_Y = σ/σ₀= K ln [coth {1/2(2e^-a0t + B)}]
where, K, a₀ and B are constants determined by experiment. In contrast, compression stress relaxation phenomena of polyester staple fiber assemblies with heteromorphic section and round section is not expressed by this equation.

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The long-term goal of this research is to design sportswear for elderly persons. In this study, we investigated the influence of four different shapes of sportswear (long-sleeved or sleeveless and zippered or zipper less) on dressing motions of young and dummy elderly persons. We experimentally prepared kits for dummy elderly persons. And psychological burdens and motions of young and dummy elderly persons dressing them were measured by sensory test and motion analysis. Subjects in the elderly-condition group felt greater psychological burden than those in the young-condition group while wearing the sportswear. Moreover, the psychological burden was greater in the case of the two clothing samples with long sleeves. When the test subjects put their arm through the sleeves of the clothing samples, the movement distance at three points (the acromion, lateral epicondyle of the humerus, and radial styloid process) were measured. In the case of the elderly-condition group, the movement distances at the radial styloid process were longer in the case of the two clothing samples with long sleeves. The results of motion analysis were in accordance with those of the psychological test.

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Temperature and humidity on the periphery of the human body is a direct factor in influencing thermal comfort. This paper describes the evaluation of thermal comfort through measurement of the physiological and psychological responses to changes in the microclimate surrounding the human body. The temperature and humidity were changed using 2 patterns: from neutral to hot, and from hot to neutral. We found that even in the same thermal state the thermal comfort zone for the 2 patterns is different during close ambient changes due to hysteresis. Based on the results of sensory testing, we have estimated the thermal comfort zone as defined by the humidity and temperature close to the human body. The thermal comfort zone was determined to be an area in the temperature range of 29 to 31 degrees Celsius with a range of 20 to 50 % relative humidity. Based on these factors, the thermal comfort zone was different for the 2 climate change patterns. We have concluded that thermal comfort varies depending on the direction of the climate change.

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