Hakki Gökhan Ilk

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This paper proposes an alternative scheme to variable bit rate (VBR) speech coding for voice over Internet protocol (VoIP) during network congestion in Internet. The proposed scheme is called ‘‘adaptive bit rate switching’’ and ensures that the available bandwidth is most efficiently used. When congestion is signaled, a time scale modification algorithm(More)
Watermarking is a major technology to achieve copyright protection and multimedia security. In this study, combination of Discrete Wavelet Transform (DWT) and Singular Value Decomposition (SVD) via Lower-and-Upper (LU) Decomposition is proposed as a watermarking algorithm. Experimental results show that proposed algorithm is robust against filtering,(More)
In this study two frameworks, made up of digrams and trigrams, are built for a complete coverage of the Turkish language. In addition, character, digram and trigram entropy values for Turkish, English and Spanish are compared. Examining meaningful Turkish texts, we have achieved the result that, there are 3 major digram clusters which constitute slightly(More)
In this paper, a fixed point Variable Bit-Rate (VBR) Mixed Excitation Linear Predictive Coding (MELP TM ) vocoder is presented. The VBR-MELP vocoder is also implemented on a TMS320C54x and it achieves virtually indistinguishable federal standard MELP quality at bit-rates between 1.0 to 1.6 kb/s. The backbone of VBRMELP vocoder is similar to that of federal(More)
In wireless commercial and military communications systems, where bandwidth is at a premium, robust low-bit-rate speech coders are essential. They operate at fix bit rates and those bit rates cannot be altered without major modifications in the vocoder design. A novel approach to vocoders, in order to reduce the bit rate required to transmit speech signal,(More)
In this study, a rule based perceptual intonation model was proposed for Turkish text-to-speech synthesis systems. A proper intonation model is required for a natural synthesized speech. The proposed model is sentence based and includes the stress patterns of compounds, inflected verbs and some punctuation marks. The offered rules were determined with the(More)
In this work human action recognition problem was discussed in video sequences. Solution of the problem was studied in three stages. Firstly, points of interest were detected with preproccesing and these points which are called cuboids were declared in small windows, then feature extraction was performed and finally, human action is decided by using(More)
Watermarking is identified as a major technology to achieve copyright protection and multimedia security. In this study, combination of Discrete Wavelet Transform (DWT) and Singular Value Decomposition (SVD) via Lower-and-Upper (LU) Decomposition is used as a transform domain watermarking algorithm with a comparative study on chaotic map approaches as(More)