In this paper a input-system control model of human operators is proposed on the basis of the fundamental characteristics obtained experimentally. This model is not characterized by applying the mathematical method to human operators as a mechanical element, but representing their responses as a combination of the input control and the system control on the basis of observation of actual control responses.
The input control is a continuous function of time generated by the input model in trained operator's brain, and is approximating to the ideal control. The system control which compensates the insufficiency of the input contr ol and reduces the error to zero, starts accompanied with the lag time when the deviation Z_in between the ideal control and the input control is over the threshold level. and shows the operation adapted to plant dynamics in consideration of Z_in in the interval of the input control.
Digital simulation results obtained in this way show close agreement with the experimental results, and validity of the model is confirmed. This model is also a fundamental model of remnant.

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Gait characteristics of three subject groups, i. e. young men (mean age of 28 years), eldely men (mean age of 70 years), and elderly women (mean age of 76 years) were investigated. In experiment I, the subjects walked on ten different walkways in outdoor. In experiment II, the subjects walked on a treadmill in order to find the influence of environmental difference between outdoors and in a laboratory room.
The results included the following:
(1) The lower the subjects' tolerance level of physical functions for work intensity was, the greater the degree that the subjects tried to suppress the increase of the work load. (2) The subjects, especially elderly groups, complain their suffering while their physiological signs still do not change remarkably. (3) The patterns of responses of both the physiological and subjective activity indexes depend on the manner of walking; whether it is active (outdoors) or passive (on the treadmill).

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One thousand measurements were made on 520 pregnant women to obtain basic data for designing of pregnant women's garments. Once or several times, pregnant women from second to 10th month of their pregnancy were measured on 44 items. The items concerning depth and girth of abdomen and waist showed a remarkable change, and linear increase after 4th month of pregnancy. But the items concerning height showed no change.
Principal component analysis revealed the body form of pregnant women can be estimated by the following three principal components. The first principal component, size factor, represents the size of the body. The second, shape factor, represents the degree of obesity. The third represents the characteristics of the body trunk of pregnant women. The scores of the first principal component increase linearly and the scores of the second and the third principal component decrease linearly with the progress of the individual pregnancy month.
Accordingly, the size of pregnant women's garment cannot be decided according to a month of pregnancy. Pregnant women's garment must be designed under consideration of the variety of sizes and shapes of body, changing with the progress of pregnant months.

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