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  • Author or Editor: Ilona Kovács x
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A tanulmány a látás fejlodését két dimenzió mentén elemzi. A lokális-integrativ dimenzió a lokális ingertulajdonságok (például szín, orientáció, mozgás, mélység) mérése, s ezek téri integrációja. Míg a lokális folyamatok viszonylag korán kialakulnak, a téri integráció lassan fejlodik. A lokális-integratív dimenziót a hátsó halántéklebenyi agyterületekkel lehet társítani. Az akció-percepció dimenzió a magasabb szintu látási muködések funkcionális felosztásán alapul, mely az anatómiailag is meghatározott két fo látópályához kapcsolódik. Az occipitoparietális vagy a dorzális látórendszeri agyi struktúrák gyors fejlodése a látáson alapuló mozgásos (vizuomotoros) kontrollban kap szerepet; míg lassabb érés, fokozottabb hajlékonyság jellemezheti a tárgyak, események kategorizálását végrehajtó occipito­tempo­rá­lis vagy ventrális látórendszert.

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The form of the second movement of the String Quartet in A major, Op. 7 is original not only in Dohnányi’s oeuvre but in music history in general, as well. This new musical idea is a fusion of two traditional forms: a variation and a ternary form. The theme of the movement is followed by four variations, but at the end of the second one there is an unexpected break: a contrasting Trio-like section comes in between and the flow of variations continues only after it finishes. This unique structure is analysed in detail for the first time in present study. Relying on analyses of Dohnányi’s compositions, this study traces similar formal characteristics in other works of the composer too. Finally, the article provides with an example for this hybrid form in one of its three closest relatives: the second movement of the Piano Quintet in Eb minor, Op. 26.

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Béla Julesz (1928–2003), known for his work in depth perception and pattern recognition, was an inspirational master to a whole generation of neuroscientists. He developed new techniques (involving computer-generated random-dot stereograms, cinematograms, and textures) that led to a new field of perceptual research called “early vision”. Julesz often emphasized the importance of “scientific bilingualism__

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The paper deals with the development of the management system of regional policy in four countries (Hungary, Poland, Slovakia and Romania). It presents the results and dilemmas concerning the creation of the territorial administration and the administrative meso-level, the special organs of regional policy and their interconnections with public administration. It also touches upon the emerging conflicts between the traditional institutions of democratic participation and publicity, and the new characteristics of the partnership networks. The presentation points out the decentralisation and modernisation challenges initiated by regional policy in the new member states in the light of European regional development strategy in the future and the domestic situation as well.

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Learning & Perception
Authors: Dov Sagi, Ilona Kovács, and Mihály Racsmány
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In the present explorative study, different time-series analysis methods, such as moving average, deterministic methods (linear trend with seasonality), and non-parametric Mann–Kendall trend test, were applied to monthly precipitation data from January 1871 to December 2014, with the aim of comparing the results of these methods and detecting the signs of climate change. The data set was provided by the University of Pannonia, and it contains monthly precipitation data of 144 years of measurements (1,728 data points) from the Keszthely Meteorological Station. This data set is special because few stations in Hungary can provide such long and continuous measurements with detailed historical background. The results of the research can provide insight into the signs of climate change in the past for the region of West Balaton. Parametric methods (linear trend and t-test for slope) for analyzing time series are the simplest ones to obtain insight into the changes in a variable over time. These methods have a requirement for normal distribution of the residuals that can be a limitation for their application. Non-parametric methods are distribution-free and investigators can get a more sophisticated view of the variable tendencies in time series.

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The primary visual cortex (V1) of the mammalian brain is equipped with a specifically connected network of neurons that can potentially solve difficult image processing tasks. These neurons are selectively tuned for locations in visual space and also for line orientation. The coupling of location and orientation tuning results in the neural representation of the visual world in terms of local features. These local features, e.g., oriented line segments, will have to be linked together in order to parse the visual world into regions corresponding to object and ground. Although standard models of V1 do not address the issue of interacting neuronal populations, we suggest that the long-range connectivity pattern of V1 provides an architecture where spreading neural activity may lead to pertinent figure-ground segmentation. The model relies on the fact that in addition to the processing units, their connections are also selectively tuned for space and orientation. From the computational point of view, the model uses a minimalist approach that applies the fundamental concepts of Gestalt psychology – proximity, similarity and continuity – to the spreading of neuronal activation signals. This model is successful in predicting psychophysical performance of human observers, and provides an account of the computational power of V1.

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Abstract

The River Tisza is one of Central Europe's most important rivers. In the last one and a half century numerous anthropogenic activities have influenced its watershed. As a result measures need to be taken to protect its water quality, necessitating a comprehensive picture of the spatial and temporal variability of its processes, which this study aims to extend further. In this study five sampling locations were analyzed in the upper section of the Tisza over the time interval 1974–2005, dealing with 24 parameters using multi-variate data analysis methods. Employing time series analysis and taking the river's tributaries into account, the strong influence of the River Szamos was pointed out, while stochastic connections indicated the influence of the Tiszalök Water Barrage System on the spatial variation of the Tisza's processes. Finally, by using principal component analysis (PCA), the different background factors were revealed in space and time (seasonal separation) as well. During summer the processes tended to be nitrogen-related, while during winter inorganic compounds play a greater role. Most importantly, spatial variety was observable in the factors.

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The estimation of environmental risk caused by pollution with potentially toxic elements (PTE) is usually carried out using the (3+1) step sequential extraction procedure suggested in 1993 by the Community Bureau of Reference (BCR). In the 1st step the water-soluble, exchangeable and carbonate-bound element content is extracted with acetic acid. In 2002 a fractionation procedure based on the application of supercritical CO2, subcritical H2O and of a mixture of subcritical H2O/CO2 was proposed, which allowed the water-soluble and carbonatebound element contents to be extracted separately from sediment or soil samples weighed into the preparative column of a supercritical fluid extractor and diluted with quartz sand in a mass ratio of 1:20. The aim of the present study was to develop a new reduced-size column construction with which this dilution rate could be decreased to 1:2. A kinetic study was performed to determine the extraction time necessary for samples with different carbonate contents and the extracted element contents were compared to the results of the BCR sequential procedure on the same samples. It was established that fractionation using the reduced-size column may be a rapid way to obtain more reliable information on the easily mobilizable (watersoluble and carbonate-bound) PTE content of soils and sediments than was previously available to supplement BCR fractionation.

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Journal of Thermal Analysis and Calorimetry
Authors: Katalin Kovács-Hadady, Éva Balázs, Ilona Kiss, Sándor Bohátka, and Gyula Szö'or
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