Schwarz, Wintzer, Gebhard, et al. have reported their studies of the frequency discriminating thresholds for flickering lights. However, data on such thresholds as changes in flicker frequencies from 10Hz to a critical fusion frequency involves problems as reference data in view of the advances in measuring instruments and difficulties in statistical processing of the data. This experimental study was conducted by separating two parallel spot of flickering lights into a standard and a variable stimulation by means of computer control. In the experiment, the subjects adjusted the frequencies of variable stimulations to the stipulated frequencies of standard stimulations by operating a handheld control. Six standard stimulations were set between 10 and 35Hz at intervals of 5Hz. Eighteen subjects with normal vision (12 males and 6 females aged 20 to 23 years) took part in the experiment. As a result, the Weber ratio (ΔS/S) was about 4% at 15, 20, 25 and 35Hz. The experimental results of Gebhard et al. could be refconfirmed with more accurate normative data.

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This paper experimentally investigates the hypothesis that the limiting oblique velocities of smooth pursuit eye movements are a function of both the limiting horizontal and vertical velocities.
The condition of the occurrence of a smooth pursuit of a visual target in the oblique direction, existed only when each eye movement in the horizontal and vertical directions on oblique-direction pursuing, was smooth pursuit. The limiting oblique velocities expressed as the resultant of the two individual movement components provided a good fit to the empirical data. These results, therefore, support the hypothesis of two independent orthogonal components in the control of smooth pursuit eye movement.
Furthermore, the largest value of the limiting velocities of smooth pursuit eye movement is obtained theoretically at the angle of about 15 degrees from the horizontal axis.

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Elderly disabled people's falling has a big risk of bone fracture. One of the main causes of falling is the failure of wheelchair brakes. This paper describes three devices which prevent this. The first of these devices gives an audible voice warning. When one side brake is applied, it starts checking the brakes and the foot plates. If the preparation for standing up is not complete, it gives a warning. The second device is designed to prevent the patient from standing up without applying the brakes. The brake lever is in front of the patient and in order to stand up, he/she must lift up this lever. In doing so, both side brakes are applied. The third device automatically applies both side brakes by using compression springs under the seat. When a patient stands up, the seat rises and automatically applies the brakes through actuating linkages. As the result of the field test at a geriatric medical center, the second device was found to be the most useful. The first device will be effective in training how to operate a wheelchair. The third device will be useful for more severely disabled patients if the mechanism is completed.

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Traditional automata perform only one pattern of motions because they are controlled by mechanical components like cams and gears. We have developed computer controlled automata which can perform various motions by changing computer programs. We try to use a human dancing motion for motion planning of the automata. But the automata has a limited degrees-of-freedom, while human dancing motions have many ones. Thus, it is difficult for us to express a human dancing motions under a limited degree-of-freedom. We propose a method to select important joints of the human dancing motion model, and to reduce degree-of-freedom by restricting unimportant ones. In this method, we evaluate the error (C_g) of centroid of each body part to decide the importance of joint. We also evaluate the generated motion by subjective evaluation. As the result, it is shown that the index C_g is useful for selecting the important joints of the human dancing motion.

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This study aims to reexamine the former definitions of a fixation point and to propose a new definition of it. One of the former definitions employs velocity of eye movements as its standard. When the actual velocity of the eye movement is kept below the limit velocity of fixation, that is 5deg/s, for a certain period of time, it is regarded as “a fixation”. But when the visual targets were moving rather fast, it is hard to detect fixation points by this definition, even when the subject can be thought to get some information. To reexamine the limit velocity of fixation and solve this problem, two measurements of eye movements were taken. By analysing the data while tracking a moving target and looking at a moving image, it was clarified that the limit velocity of fixation should be defined as about 10deg/s, if the visual targets were moving. The new definition made it possible to detect some fixation points.And the fixation points got from the analysis matched up to the position that subject had reported to have looked at. From above findings, it is suggested that the limit velocity of fixation should be defined with consideration to the velocity of visual targets.

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