2004/1

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    Neural Network Program Package for Prosody Modeling
    (Společnost pro radioelektronické inženýrství, 2004-04) Tuckova, Jana; Santarius, Jiri
    This contribution describes the programme for one part of the automatic Text-to-Speech (TTS) synthesis. Some experiments (for example [14]) documented the considerable improvement of the naturalness of synthetic speech, but this approach requires completing the input feature values by hand. This completing takes a lot of time for big files. We need to improve the prosody by other approaches which use only automatically classified features (input parameters). The artificial neural network (ANN) approach is used for the modeling of prosody parameters. The program package contains all modules necessary for the text and speech signal pre-processing, neural network training, sensitivity analysis, result processing and a module for the creation of the input data protocol for Czech speech synthesizer ARTIC [1].
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    Digital Image Watermaking in Color Models Using DCT Transformation
    (Společnost pro radioelektronické inženýrství, 2004-04) Hovancak, Rastislav; Levicky, Dusan
    In recent years, an access to multimedia data has become much easier due to the rapid growth of the Internet. While this is usually considered an improvement of everyday life, it also makes unauthorized copying and distributing of multimedia data much easier, therefore presenting a challenge in the field of copyright protection. Digital watermarking, which is inserting copyright information into the data, has been proposed to solve the problem. In this paper two original watermarking schemes based on DCT transformation for ownership verification and authentication of color images were proposed. Some color models in process of watermarks embedding and extracting are described too.
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    Contribution to the Chebyshev Approximations of the Normalized Low-Pass Prototype
    (Společnost pro radioelektronické inženýrství, 2004-04) Laipert, Milos; Vlcek, Miroslav; Vrbata, Jan
    The standard approximation algorithms are well described in the literature, but some equiripple approximations are described with some deficiencies. Especially Chebyshev and inverse Chebyshev approximations are often wrongly interpreted or implemented. In this paper, we propose all formulas for computing Chebyshev approximations in a standard form. Transformations, which are necessary for circuit implementation, are presented in the analytical form too.
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    The Performance of W-CDMA Highways Infostations
    (Společnost pro radioelektronické inženýrství, 2004-04) Taha-Ahmed, Bazil; Calvo-Ramon, Miguel; de Haro-Ariet, Leandro
    The expected value of the signal to noise ratio of W-CDMA infostations is derived. A model of 5 cells is used to analyze the system performance. The infostations are assumed to exist in rural zones. The performance of the infostations is studied for different breakpoint distances, different infostations separation, a different number of users for each infostation and for different bit rate.
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    Estimator Comparison of the Nakagami-m Parameter and its Application in Echocardiography
    (Společnost pro radioelektronické inženýrství, 2004-04) Kolar, Radim; Jirik, Radovan; Jan, Jiri
    This article deals with the comparison of various estimators of the m parameter from the Nakagami distribution. This kind of distribution has been used in many engineering applications and we present another possible application in biomedical engineering, particularly the ultrasound tissue characterization in the echocardiographic application. Matlab 6.5 was used as a proper tool for fast and efficient scientific research.