In this paper, we present a method of reducing the effect of switching noise generated from the switching power supply using a GaN (gallium nitride) device for controlling industrial equipment communication signal. We point out the noise power with its peak at the resonance frequency determined by the parasitic impedance and circuit constants. We propose a contorted communication timing where the guard interval of the communication signal and the switching noise are overlapping. Then, we propose to select the dedicated LLR (log-likelihood ratio) calculation instantaneously when the switching noise overlaps the guard interval of the communication signal in the proposed timing. Using the proposed contorted communication timing, we have improved the SNR (signal-to-noise ratio) vs BER (bit error rate) from 1.0×10^-1 to 2.5×10^-2 at the SNR of 20[dB]. In addition using the proposed LLR calculation method, the SNR vs BER is improved by more than 5 [dB] while the SNR vs PER(packet error ratio) is improved by 10[dB] at the SNR of 20[dB].

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Conventional linear prediction (LP) analysis is known to suffer from problems in estimating the formant frequencies (vocal tract resonances) of high-pitched speech signals. The performance of conventional LP analysis deteriorates due to the harmonic structure of the glottal excitation source, especially in the case of high-pitched speech signals. Attempting to resolve this problem, a pitch-synchronous analysis technique based on a short-time energy function is presented. The proposed method has been verified to reduce the effect of the harmonic structure of the glottal excitation source. Experiments were carried out using synthetic vowels and real vowels. The results show that the proposed method yields a better performance in the estimation of formant frequencies than some previous LP analysis methods.

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High efficiency video coding (HEVC) achieves significant higher coding efficiency than previous video coding standards. In the intra prediction of HEVC, prediction unit sizes from 4×4 to 64×64 are employed, respectively defined as levels 1 to 5, to achieve higher coding efficiency. Nevertheless, this is at the expense of high computational complexity. This paper proposes a fast algorithm for the intra prediction of HEVC, which can efficiently decide the level on the basis of the roberts-cross edge detector. The proposed algortihm utilizes the high correlation between regional texture and prediction unit partitioning. It is mainly composed of a bottom-up level decision method and an efficient decision flow based on an authentic image feature. Furthermore, chrominance information is also employed to decide the prediction unit partitioning. The experimental results for the proposed algorithm demonstrated that it achieved a task with greatly reduced computational complexity compared with the original HEVC. The average time-saving is approximately 37%, while the increase in bit rate and decrease in PSNR are negligible.

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The reason why I have decided to start a new lecture series is explained in this article. The main purpose of transmission lines is to carry information using wave energy over long distances, which corresponds to the use of the telegrapher's equations in circuit theory. In this lecture, a new analysis method for the telegrapher's equations is explained. In other words, the equations are solved by the Laplace transform and expressed as the Riccati equation. The eigenvalue problem of the Riccati equation is solved to obtain a transmission equation and cascade matrix. It is suggested that the steady-state response can be obtained using the cascade matrix and may be applied to quantum theory.

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