18 research outputs found

    A parametric multiclass Bayes error estimator for the multispectral scanner spatial model performance evaluation

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    The author has identified the following significant results. The probability of correct classification of various populations in data was defined as the primary performance index. The multispectral data being of multiclass nature as well, required a Bayes error estimation procedure that was dependent on a set of class statistics alone. The classification error was expressed in terms of an N dimensional integral, where N was the dimensionality of the feature space. The multispectral scanner spatial model was represented by a linear shift, invariant multiple, port system where the N spectral bands comprised the input processes. The scanner characteristic function, the relationship governing the transformation of the input spatial, and hence, spectral correlation matrices through the systems, was developed

    Robusna procedura za umetanje vodenog ┼żiga u sliku zasnovana na Hermitovoj projekcijskoj metodi

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    A procedure for combined image watermarking and compression, based on the Hermite projection method is proposed. The Hermite coefficients obtained by using the Hermite expansion are used for watermark embedding. The image can be efficiently reconstructed by using a set of Hermite coefficients that is quite smaller than the number of original ones. Hence, the watermark embedding is actually done in the compressed domain, while maintaining still high image quality (measured by high PSNR). The efficiency of the proposed procedure is proven experimentally, showing high robustness even for very strong standard attacks. Moreover, the method is robust not only to the standard attacks, but to the geometrical attacks, as well. The proposed approach can be suitable for different copyright and ownership protection purposes, especially in real-applications that require image compression, such as multimedia and Internet applications, remote sensing and satellite imaging.U radu je predlo┼żena procedura za umetanje vodenog ┼żiga u sliku i kompresiju slike zasnovana na Hermitovoj projekcijskoj metodi. Odgovaraju─çi koeficijenti, dobiveni kao rezultat primjene razvoja slike u red Hermitovih funkcija, kori┼íteni su za umetanje vodenog ┼żiga watermark). S obzirom na to da se slika mo┼że efikasno rekonstruirati kori┼ítenjem znatno manjeg broja Hermitovih koeficijenata u odnosu na broj originalnih koeficijenata slike, umetanje vodenog ┼żiga zapravo je provedeno u domeni kompresije, uz o─Źuvanje visoke kvalitete slike (velika vrijednost PSNR). U─Źinkovitost predlo┼żene procedure ispitana je eksperimentalno i pokazuje zna─Źajnu otpornost na uobi─Źajene napade. Osim uobi─Źajenih, procedura pokazuje robusnost i na geometrijske napade. Predlo┼żeni pristup mo┼że biti kori┼íten u razli─Źitim aplikacijama za za┼ítitu autorskih prava, naro─Źito u aplikacijama koje ujedno zahtijevaju i kompresiju slike, kao ┼íto su multimedijske i internetske aplikacije, daljinsko o─Źitavanje podataka i satelitska snimanja

    Cognitive Reserve and the Prevention of Dementia: the Role of Physical and Cognitive Activities

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    Purpose of Review: The article discusses the two most significant modifiable risk factors for dementia, namely, physical inactivity and lack of stimulating cognitive activity, and their effects on developing cognitive reserve. Recent Findings: Both of these leisure-time activities were associated with significant reductions in the risk of dementia in longitudinal studies. In addition, physical activity, particularly aerobic exercise, is associated with less age-related gray and white matter loss and with less neurotoxic factors. On the other hand, cognitive training studies suggest that training for executive functions (e.g., working memory) improves prefrontal network efficiency, which provides support to brain functioning in the face of cognitive decline. Summary: While physical activity preserves neuronal structural integrity and brain volume (hardware), cognitive activity strengthens the functioning and plasticity of neural circuits (software), thus supporting cognitive reserve in different ways. Future research should examine whether lifestyle interventions incorporating these two domains can reduce incident dementia

    Wavelet analysis of modulated signals

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