A configuration factor between the human body or its equivalent simple model and a rectangular plane is necessary for calculation of the mean radiant temperature and the rate of radiant heat exchange between the human body and its surroundings. A cylindrical element may be most useful for this purpose. Ibamoto and Nishi (1968) first defined configuration factors between a clyndrical element and a rectangular plane. However, their model may be insufficient because the top and bottom end of the model were not considered for the calculation. Then, configuration factors for cylindrical elements with top and bottom ends were redefined and calculated. The calculations are now graphically shown in some charts. This factor depends on the ratio of height h to diameter d of the cylindrical element. The configuration factors for cylindrical elements with the ratio h:d=1:1 and h:d=3:1 fairly corresponds to those for the seated and standing human elements reported by Fanger (1970), respectively.

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The purpose of this study is to investigate the effect of work load durations on the relationships between aerobic and anaerobic thresholds determined from gas exchange parameters, and lactate thresholds determined from blood lactate concentrations. Aerobic and anaerobic thresholds (Aer T, An T) were detected from the plot of changes in gas exchange parameters against increasing work load by a breath-by-breath system. Lactate thresholds (LT 1, LT 2) were detected from the plot of blood lactate level in the same manner as Aer T and An T. Ten normal subjects were studied doing progressive bicycle ergometer exercise (after 2 minutes warming-up at 0.5kp) until exhaustion under three experimental conditions (work load duration was increased every 1, 3 and 5 minute by 0.5kp respectively) in a random order. Neither aerobic nor anaerobic threshold expressed in VO₂ was significantly different despite of the different work load durations, but those data expressed as work load (kp) had significant differences with the different work load durations (for both Aer T and An T, p0.01). Significant correlations were found between the average values of VO₂ at Aer T and LT I (for 3 min., p0.05, for 5 min., p0.01), and between An T and LT 2 (for all of 1, 3 and 5 min., p 0.01). These results suggest that Aer T and An T were well coincide with LT 1 and 2 under any experimental conditions studied here. Therefore, it seems that Aer T and An T determined from gas exchange parameters can be used as an index of the aerobic performance in man.

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Ventilatory response to carbon dioxide in the summer and winter was measured on healthy 9 male subjects by means of CO₂ rebreathing method; the subject rebreathed a gas mixture (about 7% CO₂ in O₂) of 6 liters for 4 min after the subjects rested in a sitting position for about 20 min. During rebreathing, CO₂ concentration of expired air and tidal volume were determined continuously using an infrared CO₂, analyzer and respirometer, respectively. The mean and standard deviations for the slope of the ventilatory response line in the summer and winter were 2.42i±0.75 and 2.45±1.03 1·min¹'mmHg¹. There were no significant differences in the slope of hypercapnic ventilatory response in the summer and winter. However, ventilation corresponding to alveolar CO₂ pressure of 60mmHg calculated from regression equation of ventilatory response line were 35.2±15.6 in summer and 25.4±15.2 1·min¹ in winter, the difference being significant.

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The purpose of the present study was to derive regression equation based on anthropometric measurements to estimate pulmonary residual volume (RV) and to ascertain its applicability in calculation of body density (BD). Subjects were 30 males living in Santa Barbara, California, USA, ranging in age from 20 to 52 years. Nine anthropometric measuretnents, actual RV, vital capacity (VC), and BD using the conventional underwater weighing method were made on each subject. Four measurements (age, height, biiliac diameter, and chest diameter) were selected by Wherry-Doolittle test selection method. The resulting formula using these measurements was as follows : RV = 38.89(X1) + 30.43(X2) - 12.43(X3) + 10.70(X4) - 4573.4 (R = 0.832, SEE= 251.9ml) where RV : predicted RV (ml). X1 : age (years), X2 : height (cm), X3 : billiac diameter (mm), X4 : chest diameter (mm), R: multiple correlation coefficient. SEE : standard error of estimation. When this formula was used to calculate RV, mean absolute difference between BDS obtained by using the actual and the predicted RVs was 0.0033lg/cm³. On the other hand, the absolute differences using the formula of Goldman and Becklake, fraction of VC (24%), and the constant value (1300ml) were 0.00477g/cm³, 0.00763g/cm³, and 0.00787glcm³ respectively. It was concluded that using the formula obtained in the present study to predict RV would be a useful method in the situation where mass managements were neccesary and more precise measurements were required than the other simplified estimations. Thus in predicting RV our formula could reduce the extent of the potential error largely as compared with the other predictions. Additionally it does not require special knowledge, technique, and devices.

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Music is one aspect of acoustical environment. According to the development of technology, the music production processes and the listening situations have been considerably diversified. Recently we have had many opportunities to listen to music by electro-acoustical reproduction systems. The reproduced musical sounds are supposed to reflect the listener's desire on music. In the present study of the acoustical environment of music, the optimum listening volume of the reproduced music was measured by the psycho-acoustical experiment using a method of adjustment. A-weighted equivalent sound level was used as a criterion of loudness. Further, the musical impression was evaluated by a semantic differential method using 15 scales. The average power spectrum and the temporal sound pressure level fluctuation were measured as the acoustical properties of musical sounds. The powerful and sharp music is listened at a very large volume. The loud music usually shows a trapezoidal spectrum pattern with strong high-frequency components and a smaller fluctuation pattern of sound pressure level fluctuation. On the contrary, the soft music usually shows a triangular spectrum pattern and a larger level -fluctuation pattern.

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We examined whether indirect maximal oxygen debt (YmA or YmB) derived by a mathematical equation (Dimri et al., 1980) would accurately approximate the directly measured maximal oxygen debt. The subjects for this study were 17 healthy male volunteers (8 athletes and 9 untrained college students) 18-26 years of age. An exhaustive 60-s cycling, as an exercise stimulus for determining maximal oxygen debt, was administered to each subject on a Monark bicycle ergometer with toe-stirrups. Criteria for the resting condition were a heart rate approximately equal to his usual rate and time of his lying (more than 30 min). The maximal oxygen debt (1) was calculated as the difference between the total oxygen uptake of recovery period (60 min) and the product of the pre-exercise resting oxygen uptake (1/min) and equivalent time in minutes required for the post-exercise gas collection. The pre- and post-exercise gas collection were made each minute during the respective entire testing periods. YmA and YmB were extrapolated from the measurements of excess oxygen uptake over the pre-exercise resting value at the end of 9 min and 15 min of the post-exercise period respectively ; and both were assumed to represent maximal oxygen debt over a 60 min period. YmA (6.73±2.60l) and YmB (6.24±2.10l) calculated from the extrapolation procedure were highly correlated (r=0.950 and r=0.940, respectively) with observed maximal oxygen debt. Absolute oxygen debt determined by the extrapolation procedure, however, differed siguificantly (P< 0.001) from the directly measured maximal oxygen debt (7.31±2.00l), i.e., YmA and YmB were 0.581 (or 7.9%) and 0.891 (12.2%) lower than the directly measured maximal oxygen debt. It is suggested that the extrapolation procedure proposed by Dimri et al. needs to be investigated in further studies.

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