The instrument is developped for the measurement of the speed and the accuracy in a target pointing motion. It consists of LED matrix board, a digitizer and a microcomputer.
It works as follows. By illuminating LED, LED matrix board indicates the target position to the subject. The subject is to point the position by a pen, an fast and correct as possible. The digitizer measures the pointed position. And the timer in the microcomputer calculates period of time between the moment LED illuminates and the moment the subject points the position. If the distance between the assigned position and pointed position is within the given allowance, the measuring process goes on. Otherwise the subject must repeat the same positioning.
This instrument is expected to determine the proper size and position of the Kanji-characters on the Kanji-input device.

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The purpose of the present study is to deside the optimum size of targets which are arranged on the display-board in the Kanji-input device. Twelve persons are participated as the subjects. Their task is pointing with the write-pen successively 100 targets lighted in order on the display-board.
The results are as follows;
1) The percentage of correct responses increased in proportion to the logalithmic enlargement of the target-size in the range of 4×4mm, 6×6mm and 10×10mm.
2) The number of mispointings and the time required to finish 100 pointings decreased in proportion to the logalithmic enlargement of the target-size.
3) Considering the trading-off between pointing acuracy and consuming time, it was concluded in this experimental situation that at least 6×6mm was required as the target-size and that the target-size of 10×10mm was quite enough.
4) There was the tendency to show the better results of the pointings in the right hand side, namely, the area of the hand holding the pen, apparently corresponding to easiness of hand movements.

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The purpose of this study is to develop a simple measurement of three-dimensional movements from motion picture film taken from one direction. The principle of this measurement is focussed on the difference between the actual length and the projected. The points in the three-dimensional coordinates are determined from the difference through the calculation processing.
The advantages of this method are as follows;
1) The recording arrangement provided with one motion picture camera.
2) There are few limitations in consideration to determine the place for recording.
3) This method does not involve any discomfort for subject.
The method was applied to the measurement of knee joint angles in walking. The results obtained agreed with the previous report using a goniometer. This method developed by the present study is available for three-dimensional measurement.

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Process of visual interpolation of an one-mm. extent between two scale lines was analyzed from the point of view of information theory. Theoretical simulations by means of three kinds of model on hypothetical observers and an experimental study with three human observers were conducted on the same situation. Transmitted information, ambiguity, and output information were obtained from both simulation data and experimental data. Experimental data indicated a systematic bias of scale reading that observers judged the positing of pointer nearer to the center of the empty extent than its physical position. This bias was strongest at a quarter from the both ends of the extent. A model including discriminal dispersions (random fluctuation) and a systematic bias fitted the experimental results. The standard deviation of the discriminal dispersion was inferred to be approximately 0.02 of the extent from the comparison of simulation and experimental data. The amplitude of bias was inferred to be 0.06 to 0.09. Four kinds of steps, 1/5, 1/10, 1/20, and 1/40 steps, were used in the scale reading. The obtained SN ratio (transmitted information to amguity ratios) indicated that the 1/10 steps are small enough to reach a nearly maximum SN ratio.

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This paper discusses pilot dynamics from the optimality point of view. The optimal pilot model in a compensatory feedback system, where the controlled element is a stable but oscillatory second-order system, is theoretically calculated as a Wiener filter, and is compared with the pilot describing functions obtained in an experiment. Two kinds of performance indices are used to calculate the optimal pilot model. The comparison shows that (1) the pilot may behave as an approximately optimal controller and (2) the performance index consisting of the mean square error and the mean square pilot-control rate better explains the pilot dynamics.

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The purpose of this study was to investigate the relationship between paced (conveyer system) and unpaced work under various conditions. A comparison has been made among their physiological functions and changes in the quantity or in the quality of performance for operators. The subjects were eight healthy male students. They were engaged in the stamping tasks as a simple repetitive hand work. In the unpaced work, operators worked freely for 30min., 120min., and 150min. at their own pace. In the paced work, they worked for 120min. under two conditions in velocity that adopted the mean cycle time of the unpaced conditions and that was one point five times of the mean cycle time in the unpaced 120min. work.
The results obtained were as follows;
1) The TAF value in 150min. and 120min. tasks under the unpaced work lowered significantly. When the conveyer speed is equal to one point five times of the mean cycle time in the unpaced work, TAP showed the significant lowering.
2) Complaints of subjective symptoms on conveyer systems were apt to increase in comparison with those in the unpaced work conditions.
3) Unsatisfactory results of stamped papers were in the greatest quantity in 150min. task under unpaced work, but when the conveyer speed was kept to one point five times of the mean cycle time in the unpaced work, they were the smallest quantity.
4) When a continuous working hour was not instructed to the operators under the unpaced work, the operation efficiency decreased exponentially in parallel with the increase of working hours.

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