The table look-up is a powerful method for high-speed execution of the Hough transform, and this paper describes how an efficient look-up table should be arranged. Investigating the constitution of the table from the viewpoint of size, number of execution steps, execution times, amount of error, etc reveals that the best way is to prepare a table based on the equationρ=r·sin (θ+φ), derived from p=x·cosθ+y·sinθ (which is the original equation of the Hough transform) A software experiment showed that the time of θ-ρ plane drawing is reduced 80-fold from that using the original Hough transform equation The proposed principle is implemented in experimental hardware in which the dimension of the plane in 512 (9bit) ×512, and only one ROM.The drawing time for one point on the θ-ρ plane is less than 100 ns.

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This study proposes a new method for estimating visual load rapidly and objectively The physiological indices used are the closing and opening durations of each spontaneous blink, which durations are derived from the peak of the electro-oculography waveform. Three experiments respectively investigating the changes of the closing and opening durations due to the experimental visual load, due to the biological rhythm, and due to the width of the palpebral fissure showed that the opening duraion of a spontaneous blink is prolonged by the visual load This effect does not depend on the biological rhythm, interindividual variations, and the initial width of the palpebral fissure

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The transmitter whose performance is described here uses hybrid modulation to produce an AM wave directly from the digitalized audio signal. In the prototype transmitter, the efficiency of the analogue-type power amplifier was too low for transmitters with much higher output because the analogue signal from the D/A converter was amplified linearly Using a carrier PWM modulator resulted in a module efficiency of 80%, twice that of the conventional one Since this transmitter has no modulator module like that in conventional transmitter, an overall efficiency of 84-93% (RF output/DC input) is obtained in the MF band. And because transient overvoltages do not occur when the output of the transmitter is shorted, power devices can be protected from breakdowns. In addition, using the serial-type combiner could greatly suppress impulse surges from the output. When a 10-kV (peak) impulse surge was impressed at the output transmitter, only a few volts (peak) appeared at the output of the RF power modules. This means that this tramsmitter is 30-40 times more resistant to lightning surges than conventional transmitters are.

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To find out how fixation points change when one gazes at the rim of a cylinder and the visibility of its upper surface changes, we measured binocular eye movements. When the upper surface is invisible, the fixation position is distributed within a bounded region. When the upper surface is visible, either (1) the fixation position is distributed on the inferred surface of an curved object or (2) the fixation position shifts to a background. From these results we conjecture that when the upper surface of a cylinder is visible, the fixation position is not located at the corresponding rim for each eye but (1) is located on the inferred surface's depth or (2) shifts to the background. This implies that a clue to a shape's contour is important in estimating the depth and inferred shapes of objects and that depth perception is reflected by eye movements.

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[in Japanese]

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[in Japanese]

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