Hyun-Yeol Chung

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In this paper, we propose a discrete wavelet transform (DWT) based watermarking method, which can be conveniently integrated in up-coming JPEG-2000 baseline. Conventional DWT based watermarking techniques insert a watermark into the coefficients after the transform completed, while the proposed method inserts a watermark into the coefficients obtained from(More)
In this paper, we present some methods to improve the performance of microphone array speech recognition system based on Limabeam algorithm. For improving recognition accuracy, we proposed weighted Mahalanobis distance (WMD) based on traditional distance measure in a Gaussian classifier and is a modified method to give weights for different features in it(More)
A Speech and Character Combined Recognition System (SCCRS) is developed for working on PDA (Personal Digital Assistants) or on mobile devices. In SCCRS, feature extraction for speech and for character is carried out separately, but recognition is performed in an engine. The recognition engine employs essentially CHMM (Continuous Hidden Markov Model)(More)
The difference between training and testing environments is the major reason of performance degradation of speech recognition. In this paper, to further decrease the mismatch, we apply temporal filtering, Auto-Regression and Moving-Average (ARMA) filtering or RelAtive SpecTrAl (RASTA) filtering, as a post-processor for the log-Energy dynamic Range(More)