Wyniki wyszukiwania - BazTech

1

Application of satellite observations for the evaluation of the land surface temperature from GEM model forecast

Gawuc L., Struzewska J., Kaminski J. W., Durka P.

Challenges of Modern Technology

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2014

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Vol. 5, no. 2

25--32

EN

Application of satellite observations for the evaluation of the land surface temperature from GEM model forecastAbstract: The Global Environmental Multiscale model (GEM) was evaluated against satellite observations and measurements from synoptic stations. The computational grid was set up in the global variable mode with the resolution of ~25 km over Central Europe. Model evaluation was performed over Central Europe within a window of 43-56°N latitude and 10-25°E longitude. Surface temperature forecasts were compared with the Moderate Resolution Imaging Spectroradiometer (MODIS) land surface temperature product. Air temperature measured at the height of 2 metres was obtained from about 480 synoptic stations from 13 Central Europe countries. Air temperature measurements collected at 9 UTC and 12 UTC during five days (31 January, 2 February, 3 March, 27 April and 18 June 2012) was compared with the GEM model results. Evaluation showed good agreement between modelled and observed data. In case of air temperature, the averaged value of the Mean Bias Error (MBE) was -0.42, the averaged Root Mean Square Error (RMSE) and the Mean Absolute Gross Errors (MAGE) were 3.21 and 2.32, respectively. Land surface temperature comparisons gave results of -2.01; 3.91 and 3.24 of the (MBE), (RMSE), and (MAGE), respectively. Also, correlation of derived modelling errors between surface temperature and air temperature are discussed. In each case the correlation coefficient was positive. The highest value (0.70) was obtained for periods when surface – atmosphere radiative exchange processes were dominant.

2

User-centered design of brain-computer interfaces: OpenBCI.pl and BCI Appliance

Durka P., Kuś R., Żygierewicz J., Michalska M., Milanowski P., Łabęcki M., Sputek T., Laszuk D., Duszyk A., Kruszyński M.

Bulletin of the Polish Academy of Sciences. Technical Sciences

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2012

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Vol. 60, nr 3

427-431

EN

Brain-Computer Interface (BCI) allows for non-muscular communication with external world, which may be the only way of communication for patients in a locked-in state. This paper presents a complete software framework for BCI, a novel hardware solution for stimuli rendering in BCIs based on Steady State Visual Evoked Potentials (SSVEP), and a univariate algorithm for detection of SSVEP in the EEG time series. OpenBCI is a complete software framework for brain-computer interfaces. Owing to an open license and modular architecture, it allows for flexible implementations of different communication channels in the serial or parallel hybrid mode, minimization of costs and improvements of stability and efficiency. Complete software is freely available from http://openbci.pl. BCI Appliance is a hardware solution that allows for dynamic control of menus with stable generation of stimuli for the SSVEP paradigm. The novelty consists of a design, whereby the LCD screen is illuminated from behind using an array of LEDs. Design pioneers also proposed a new line of thought about the user-centered design of BCI systems: a simple box with one on/off button, minimum embedded software, wireless connections to domotic and EEG acquisition devices, and user-controlled mode switching in a hybrid BCI.

3

Neuroinformatics

Durka P.

Bio-Algorithms and Med-Systems

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2011

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Vol. 7, no. 3

29--34

EN

This article describes the world's first BSc course in Neuroinformatics, launched in 2009 at the Faculty of Physics, University of Warsaw. The curriculum includes solid background in physics, mathematics, informatics, statistics and signal processing, and parallel biomedical course from basics of biochemistry, biology and histology, to bioelectricity and neurobiology. Over 300 hours of biosignals laboratories are run entirely on GPL (open source) software, which students are free to explore, modify and use at no charge in future businesses including e.g. neurofeedback, brain-computer interfaces or eyetracking applications. Project of a matching MSc course has been submitted to the Ministry.

4

Nowe rozwiązania w stacjach transformatorowych SN/nn w aspekcie aktualnych wymagań normalizacyjnych

Durka P.

Wiadomości Projektanta Budownictwa

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2009

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nr 12

10--12

5

Szacowanie istotności statystycznej zmian w mocy sygnału EEG związanego z bodźcem

Żygierewicz J., Durka P., Mazurkiewicz J., Crone N., Franaszczuk P.

Bio-Algorithms and Med-Systems

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2005

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Vol. 1, no. 1/2

339--347

PL

Interesujących danych na temat przetwarzania informacji przez mózg dostarczają badania zmian synchronizacji aktywności komórek piramidowych kory mózgowej związanych z reakcjami na proste zdarzenia. Zmiany synchronizacji przejawiają się jako zmiany mocy sygnału EEG lub ECoG. Szacowanie istotności statystycznej tych zmian mocy stwarza kilka praktycznych problemów. W artykule zaproponowano kompleksowe ich rozwiązanie. Składa się ono z następujących kroków: oszacowania gęstości energii sygnału EEG w dziedzinie czas-częstość, wyznaczenia średnich zmian mocy, oszacowania ich istotności statystycznej wraz z poprawkami na wykonywanie testów wielokrotnych oraz weryfikowania hipotez dotyczących współzależności zmian zachodzących w różnych pasmach częstości.

EN

Event related changes in the synchronization of pyramidal neurons activity are a valuable source of information about the information processing in the brain. These changes can be measured as the changes in the power of EEG or ECoG signal. This paper presents a methodology of estimating the statistical significance of those changes. It consists of the following steps: estimation of signal energy density in the time-frequency space, computation of mean relative changes of power and assessment of their significance with the respect of multiple comparison problem, and testing the hypothesis concerning the possible covariance of different band-power changes. Usefulness of this methodology is presented on ECoG data.

6

Inter-neuro: from chaos to neuroinformatics knowledge base

Blinowski G., Durka P., Spasiński A.

Journal of Medical Informatics & Technologies

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2004

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Vol. 7

KB33--40

EN

Almost unlimited possibilities of sharing neuroinformatics resources, opened by the Internet, create an almost unlimited number of issues. Growing amount of available data, combined with the lack of reliable and large enough metainformation resources, limits the proliferation and reliability of this media. In this paper we propose a solution, which may help in an efficient sharing of neuroinformatics resources, by means of a network of vortals dedicated to particular and well defined topics. These vortals are responsible for collection of high quality resources in their particular fields. They are interconnected in a way transparent to the user, using a low level interface for interchanging queries. For a user this means that a query entered in one of the vortals will return relevant results found also in the other vortals of the Network. We also describe technical details and pilot implementation; metainformation is based upon Open Archives/ Dublin Core standards, and interchange of queries on XML/SOAP.

7

Elektroencefalogram i przybliżenia adaptacyjne sygnałów

Durka P.

Postępy Fizyki

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1999

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T. 50, z. 5

234-240

EN

Research on the electrical activity of the brain (electroencephalogram, EEG) has over a 100 years history - with Polish scientists among the pioneers. In spite of a rapid development of new brain imaging systems, EEG still retains a privileged position. With greatly improved recording techniques, analysis of these data poses nowadays a major challenge. New signal processing techniques (adaptive approximations) are suitable for analysis of non-stationary signals and provide time-frequency resolution, superior to any of the previously known methods. A unified parametrization of transient and stationary phenomena is possible within the presented framework.