Huseyin Koçak

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The electroencephalogram (EEG), like many other biological phenomena, is quite likely governed by nonlinear dynamics. Certain characteristics of the underlying dynamics have recently been quantified by computing the correlation dimensions (D2) of EEG time series data. In this paper, D2 of the unbiased autocovariance function of the scalp EEG data was used(More)
Analysis of drifter trajectories in the Gulf of Mexico has revealed the existence of a region on the southern portion of the West Florida Shelf (WFS) that is not visited by drifters that are released outside of the region. This so-called "forbidden zone" (FZ) suggests the existence of a persistent cross-shelf transport barrier on the southern portion of the(More)
Several theories have been proposed to explain the development of harmful algal blooms (HABs) produced by the toxic dinoflagellate Karenia brevis on the West Florida Shelf. However, because the early stages of HAB development are usually not detected, these theories have been so far very difficult to verify. In this paper we employ simulated Lagrangian(More)
Motivated by observations of surface drifters in the Adriatic Sea, transport in a three-gyre system is studied with the aid of dynamical systems techniques. Particular attention is paid to the issue of intergyre transport. The velocity field is assumed to be two-dimensional and incompressible, and composed of a steady three-gyre background flow on which a(More)
Despite many advances, still image storage and transfer, particularly in low-cost devices, remain to be important problems. For example, some wireless phone displays do not have the capacity to handle true colors. To remedy this problem, a color quantization (color palette) technique is often applied to images in order to reduce the number of colors.(More)
Pseudo-color images are widely used on World-Wide-Web (WWW) to reduce file storage, RAM, video memory buffer space, and to speed up data transfers. A pseudo-color image consists of indices and indices are stored in a file with raster scan order. The investigations on different scanning patterns in filing of indices showed that further improvements on(More)
We empirically study power consumptions of two linear transformations and lossless data compression algorithms on a TI MSP432 microcontroller. We developed a custom circuit using a TI INA219 breakout board and an Arduino Uno R3 board and programmed it to record power usage automatically. We validated the accuracy of our measurements with that obtained from(More)
The pseudo-distance technique (PDT) in lossless compression of color-mapped images has proved to be effective. We showed previously that by utilizing the PDT along with the Burrows-Wheeler transformation and an entropy coder, we obtained better compression gain than other well-known generic image compressors e.g. Portable Network Graphics (PNG). Most of(More)
Turin guested a " WORKSHOP ON DYNAMICS ". We invited six among the speakers to write a survey for this special issue of the Journal. Zanolin wrote a paper with coauthors, moreover Matteo Franca's survey is based on the seminar delivered by Russell Johnson at the Workshop. Some of the articles present new results in a more general framework, so they also(More)
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