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1

Analysis of epileptic EEG signals by using dynamic mode decomposition and spectrum

Karabiber Cura Ozlem, Akan Aydin

Biocybernetics and Biomedical Engineering

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2021

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Vol. 41, no. 1

28--44

EN

Dynamic mode decomposition (DMD) is a new matrix decomposition method proposed as an iterative solution to problems in fluid flow analysis. Recently, DMD algorithm has successfully been applied to the analysis of non-stationary signals such as neural recordings. In this study, we propose single-channel, and multi-channel EEG based DMD approaches for the analysis of epileptic EEG signals. We investigate the possibility of utilizing the ‘‘DMD Spectrum’’ for the classification of pre-seizure and seizure EEG segments. We introduce higher-order DMD spectral moments and DMD sub-band powers, and extract them as features for the classification of epileptic EEG signals. Experiments are conducted on multi-channel EEG signals collected from 16 epilepsy patients. Single-channel, and multi-channel EEG based DMD approaches have been tested on epileptic EEG data recorded from only right, only left, and both brain hemisphere channels. Performance of various classifiers using the proposed DMD-Spectral based features are compared with that of traditional spectral features. Experimental results reveal that the higher order DMD spectral moments and DMD sub-band power features introduced in this study, outperform the analogous spectral features calculated from traditional power spectrum.

2

Model order reduction for a flow past a wall-mounted cylinder

Stankiewicz W., Kotecki K., Morzyński M., Roszak R., Szeliga W.

Archives of Mechanics

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2016

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Vol. 68, nr 2

161--176

EN

Reduced order models allow quickly predict fluid behaviour and to better understand flow phenomena. They are the key enablers of closed-loop flow control. In this paper, reduced-order model (ROM) of an incompressible flow around a wall-mounted cylinder is constructed, by means of Galerkin projection of Navier–Stokes equations onto space spanned by the most dominant eigenmodes of dynamic mode decomposition (DMD). Additionally, genetic algorithm-based calibration is applied to improve the predictive performance of the model. The resulting low-dimensional model of the flow consists of six degrees of freedom and precisely reproduces the dynamics of limit cycle oscillations.

3

Modal analysis of viscous flow and reduced order models

Nowak M., Stankiewicz W., Morzyński M.

Vibrations in Physical Systems

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2014

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Vol. 26

223--228

EN

Phenomena occurring in the flows are very complex. Their interpretation, as well as an effective impact on them in the flow control is often only possible with the use of modal analysis and low-dimensional models. In this paper, the selected modal decomposition techniques, namely Proper Orthogonal Decomposition (POD), Dynamic Mode Decomposition (DMD) and global stability analysis, are briefly introduced. The design of Reduced Order models basing on Galerkin projection is presented on the example of the flow past a bluff body. Finally, the issues of widening of the application of the models are addressed.

4

Exposure of printed circuits by sub-pixel scroll method

Domanowski P., Wocianiec R.

Journal of Polish CIMAC

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2013

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Vol. 8, no 3

25--30

EN

Abstract The article shows principle of operation of the direct transfer of the image, and the idea of sub-pixel image scroll used in digital platesetter. It consists of a UV radiation source, the micro mirror image forming, system of the projection of an image onto the photopolymer and placed in the optical path mirror deflecting UV rays at an angle of 45°, and associated with the piezoelectric actuator. Such shaped optical system allows the usage of sub-pixel scrolling image projected on the photopolymer. The second mirror with the actuator deflecting the image in a direction perpendicular to the primary scanning direction placed in the optical path allows to increase the accuracy of the transfer of the image.

5

Zastosowanie matryc DMD do bezpośredniego naświetlania obrazu ścieżek elektrycznych o wysokiej gęstości upakowania na płytkach drukowanych

Barbucha R., Kocik M., Mizeraczyk J.

Elektronika : konstrukcje, technologie, zastosowania

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2008

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Vol. 49, nr 1

52-53

PL

W ostatnich latach coraz więcej firm polskich zaczęło produkować tzw. płytki wielowarstwowe. Obwody drukowane na poszczególnych warstwach w takich płytkach coraz częściej są wykonywane na świecie w technologii HDI (High Density Interconnects), co pozwala na znaczą optymalizację połączeń w procesie projektowania obwodu drukowanego (a tym samym miniaturyzację całej płytki drukowanej). Aby wykonać obwód drukowany w płytce wielowarstwowej o dużej gęstości połączeń, konieczne jest stosowanie metody bezpośredniego naświetlania laserowego mozaiki ścieżek na poszczególnych warstwach płytki drukowanej. Tzw. technologia LDI (Laser Direct Imaging) jest - jak na razie - jedyną komercyjnie dostępną technologią umożliwiającą wykonywanie połączeń w technologii HDI. Pracując nad własną metodą i modelem urządzenia laserowego do bezpośredniego naświetlania mozaiki ścieżek na PD, stwierdziliśmy, że możliwe jest udoskonalenie technologii naświetlania mozaiki ścieżek na PD, łączące zalety metody konwencjonalnej (jednorazowe naświetlenie całkowitego obrazu mozaiki z rozdzielczością 100 µm/100 µm) z metodą LDI (wysoka rozdzielczość 50 µm/50 µm, ale "rysowanie" mozaiki "linia po linii"). W artykule przedstawiono ideę zastosowania modułów DMD do naświetlania mozaiki ścieżek na PD.

EN

In this paper we present the application of DMD device into direct imaging process for high density interconnects PCB manufacturing. Our experiment setup consisted of DMD module, UV lamp and XY Table. We used UV-A lamp, because most of available photoresists used in process of imaging are sensitive for radiation ranged from 350 nm to 400 nm. Our method for creating electric patterns on PCB covered by photoresist consist on projecting pattern directly on photoresist. If dimensions of pattern are larger than dimensions of DMD matrix, then the whole pattern is divided into smaller sub-patterns, which dimensions are the same as DMD matrix. We used XY table to move PCB to the next sub-pattern position. The results of our investigations shows, that is possible to achieve good quality of PCB electric patterns at very high density of tracks. Moreover, our system for imaging can be successfully turned from prototype into commercial system. Of course, the estimated price will be much more lower comparing with very expensive LDI systems.