The author presented the opinion about environment in the area of ergonomics. In the present time environmental conditions should be carried out as the man (man-machine system)-system from the standpoint of public nuisance, and also from the view point of terrestrial ecology. As the thema of research and development of environment in ergonomics, (1) Research and Development (R&D) of environments, which includes the outer information. (2) R&D of environmental control system, (3) R&D of human adaptability, (4) R&D of environmental control system, which makes up the human conditions. (5) R&D of generalized evaluation method of environment, (6) R&D of environmental manikin, (7) R&D of human reactive pattern for environment.

View full abstract

Glare can cause discomfort, or it can affect the visual performance; or it can do both, thereto the visual discomfort brought about by glare is of a subjective nature.
In this paper, I described the recent researches in discomfort glare in various countries.
A number of investigators have been working on methods for evaluating the discomfort glare. Many formulas of discomfort glare rating of luminans environment have been presented by National Committees on Illumination at the CIE meeting, Washington, 1967. German DIN glare evaluation system is related to the luminance limitation of luminaire.

View full abstract

The optimum temperature for workers depends, of course, on metabolic rate of work, race, sex, age, clothing, climate of the districts, and state of acclimatization.
Ishikawa advocated that the optimum temperature could be defined from three different points of view as follows: 1) subjective optimum temperature, 2) productive optimum temperature, 3) physiological optimum temperature. According to him, the subjective optimum temperature means the most comfortable temperature, and the productive optimum temperature means the temperature at which workers show their highest efficiency. It is considered, however, that the subjective and productive optimum temperature ought to coincide with the physiological optimum temperature. The productive optimum temperature for typewriting seemed to range from 10°C to 20°C and that for purely mental work such as addition seemed to be 25°C. It seemed that many of workers at present would prefer somewhat higher temperature than those just after the World War II. Twenty years ago the average homes and offices were not so well heated as today, and clothing worn on the average was considerable heavier. The workers engaged in sedentary light work felt indifferent and pleasant at rather a high temperature in summer and rather a low temperature in winter
The difference of the optimum temperature in dayshift from that in nightshift must be attributable to the circadian rhythm of physiological functions.

View full abstract

There are the following problems on the subjective estimation of sound in the field of ergonomics. At first estimation of sound quality when transmitted through electrical sound reproducing system such as radio, telephone, record, magnetic tape, etc. comes into question. Frequency distortion, non-linear distortion, one-circuit sound reproducing system acoustic characteristics of listening room are the good examples included in this problem. Besides, there are the problems of subjective estimation and tolerance level of noises and the caliculation of articulation score and intelligibility of speech when transmitted through electrical sound reproducing system or among some noises. In this paper referring the previous studies we gave an outline of the problems andmethods, mentioned above, concerning the subjective estimation of sound from the viewpoint of ergonomics.

View full abstract

One of the aims of this paper is a presentation of the results concerning the frequency characters, noise contours, NNI contours and PWL (A) of aircraft in flight obtained from the measured values of sound level in the vicinity of Osaka International Airport. Another aim is a suggestion of some remedies for the noise-problem around the airport.
The noise from aircraft in flight in the area in question was found the most intense in the slender zone right beneath the take-off flight path. In this zone the effects of noise upon the inhabitants are observed unbearable to them, judging from the NNI values there.
The first radical step to settle this noise problem is, of course, the removal of the airport itself. For the present, however; in order to reduce the effects of the noise these measures should be taken: (1) putting in force the noise certification by establi shing a noise criterion which will be settled below the present noise level of aircraft within the technological possibility, (2) shifting the present flight paths to improved ones, (3) controlling the number of flights in the airport.

View full abstract

Interval and ratio scales on human vibration sensation are determined in order to establish evaluation methods for compound sinusoidal and random vibrations. Namely, perceptional threshold (minimum perceptible value) and equal sensation (vibration acceleration level (VAL) of the sinusoidal vibration of 20Hz as the standard, just when the sensation of the vibration is equalized to that of the vibration of 20Hz) are measured for sinusoidal and octave band random vibrations and “vibration greatness level” of an interval scale (unit in VGL) is defined from this result. “Vibration greatness” (unit in VG) of a ratio scale in which the additional principle holds good is obtained by experiment.
Then, a weighting summation method for VG values of frequency components of the compound sinusoidal and the random vibrations analyzed by an octave band filter is examined (VG_T=VG_M+0.3(∑VG_i-VG_M), where the VG_M value is the maximum value of VG_i), The sensation of these compound sinusoidal and random vibrations is compared to that of the sinusoidal vibration of 20Hz to obtain their VGL values, and these VGL values are changed to VG values (VG_{T, ob}), It is concluded that the weighting summation method can estimate their VGL values within±3dB in an accuracy.

View full abstract

Proposed scales of apparent brightness are introduced, which were reported by S. S. Stevens and R. G. Hopkinson. Procedures for designing visual environment were briefly stated on the basis of the scales of apparent brightness.
The present authors propose following further studies on the application of apparent brightness to illuminating engineering: 1) Consideration of effect of brightness contrast and constancy in addition to adaptation on prediction of apparent brightness. 2) Relations between visual functions and apparent brightness. 3) Specification of pleasant or comfort distribution of apparent brightness in visual environment. 4) Specification of the design procedure of visual environment based on apparent brightness for easier use. 5) Necessity to use apparent brightness meter, which is similar to the color appearance meter desingned by R. W. G. Hunt. 6) Necessity of interim international unification of scales of apparent brightness. 7) Necessity to establish the system to appraise visual environment subjectively, which woluld calrify the relation between the pleasantness (or comfortability) and apparent brightness.

View full abstract