[in Japanese]

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[in Japanese]

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This paper describes an original concurrent decoding method for multi-channel motion videos which is useful for B-ISDN telecommunication services Because decoding activity varies with significant block rates (SBR), sharing the decoding facility would reduce its size. To investigate this possibility, typical SBR of several motion videos are measured and decoding facility reduction is estimated. An alternative decoding scheme which prevents decoder congestion by using the transform domain integration method (TIM) is proposed and its performance is studied by simulation.

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Many TV stations use Rubidium atomic frequency oscillators (Rb OSC) to generate the chrominance sub-carrier frequency (F_sc). F_sc is widely used for practical frequency distribution and comparison. Compared to other frequency standards, F_sc has more advantages vis-a-vis complexity of instrumental equipment and measuring time. On the other hand, more and more video carrier frequencies (F_ν) of TV stations are stabillized by the Rb OSC, and the F_ν can be used for new frequency standards.
This paper compares F_ν and F_sc for frequency stability and accuracy. Experiments show F_ν stability is about 5 to 20 times superior to, but less accurate than F_sc which is periodically calibrated. It is clear from this study that F_ν has priority for use as a highly accurate practical frequency standard with periodical calibration.

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This paper describes an analog 3-state switching circuit which supplies current to display elements to set the display or undisplay state of the matrix display panel. The circuit consists of two groups of complementary transistors, and supplies either positive current, negative current or isolation by three control voltages. When applied to the matrix circuit, elements can be collectively selected in the row or the column.
Experimental results are verified through results of circuit analysis using Ebers-Moll's model. The source voltage and the control voltage are determined by considering the maximum load current. The 3-state circuit design and the matrix display circuit design with 3-state circuits are simple and power is not consumed during the display or the undisplay state.

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Motion compensated prediction is one of the most important techniques in image coding. A comparison between motion compensated interfield and interframe predictions is conducted through theoretical investigation and computer simulation. The results show that interfield prediction has advantages of better or equal performance to interframe prediction and narrower vector search range, although it is disadvantageous for certain kinds of movement, such as horizontal panning. The results also indicate that hybrid motion compensation, where interfield motion compensation is combined with horizontally one-directional interframe motion compensation, is an effective method.

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[in Japanese]

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[in Japanese]

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