TAGUCHI Ryo (MURAKAMI laboratory), a second-year master’s student in the Electrical Engineering Program received the Electronics, Information and Systems Research Group Encouragement Award of the Institute of Electrical Engineers of Japan (IEEJ) in 2025. This award was presented to TAGUCHI in recognition of his research findings titled “Signal Start Point Estimation Based on the Least-Squares Error Norm of the Frequency Spectrum and Computational Complexity Reduction via Polynomial Approximation,” which he presented at the IEEJ Joint Technical Meeting on Systems and Control in June 2025.
This research is one of several efforts addressing a phenomenon known as “frequency leakage” that occurs in the short-time Fourier transform (STFT), which is widely used in the processing of time-series signals such as audio signals. When the short-time signal subjected to the STFT contains the exact moment the signal begins (the starting point), a greater amount of frequency leakage occurs than usual, causing momentary performance degradation in various signal processing techniques. In his research, TAGUCHI developed a method for estimating the starting point of a signal contained within a short-time signal to mitigate the adverse effects caused by increased frequency leakage. Furthermore, by introducing spectral approximation using a mathematical technique known as Taylor expansion into the developed signal start point estimation method, he succeeded in significantly reducing the amount of necessary computation without degrading estimation performance.