Yasar Kemal Alp

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a r t i c l e i n f o a b s t r a c t Since Hermite–Gaussian (HG) functions provide an orthonormal basis with the most compact time– frequency supports (TFSs), they are ideally suited for time–frequency component analysis of finite energy signals. For a signal component whose TFS tightly fits into a circular region around the origin, HG function expansion(More)
Localization of the sources of Event Related Potentials (ERP) is a challenging inverse problem, especially to resolve sources of neural activity occurring simultaneously. By using an effective dipole source model, we propose a new technique for accurate source localization of ERP signals. The parameters of the dipole ERP sources are optimally chosen by(More)
In phased array antennas, by varying the complex element weights beam patterns with desired shapes can be synthesized and/or steered to desired directions. These complex weights can be implemented by using amplitude controllers and phase shifters at the system level. Since controlling the phase of an RF signal is much easier than controlling its power, many(More)
Ultra-Wideband (UWB) communication systems have been developed for short distance, high data rate communications. To avoid interfering with the existing systems in the same environment, very short duration pulses used by these systems should satisfy a predefined spectral mask. Data rate of UWB systems can be increased by using multiple pulse shapes(More)
For a signal component whose time-frequency support tightly fits into a circular region around origin, Hermite-Gaussian function expansion provides optimal representation by using the fewest number of basis functions. However, for signal components which have non-circular time-frequency supports away from the origin, straight forward expansions require(More)
A time-frequency signal analysis technique for detection and extraction of signal components is developed. The proposed technique is observed to be successful even under high noise levels, for signals whose components have compact support in the time-frequency plane. It is an iterative algorithm which detects and extracts one component at a time. The robust(More)
The lack of boundary information in region based image segmentation algorithms resulted in many hybrid methods that integrate the complementary information sources of region and boundary, in order to increase the segmentation performance. In compliance with this trend, we propose a novel method to unify the region and boundary characteristics within the(More)
The advances in convex optimization techniques have offered new formulations of design with improved control over the performance of FIR filters. By using lifting techniques, the design of a length- L FIR filter can be formulated as a convex semidefinite program (SDP) in terms of an L×L matrix that must be rank-1. Although this formulation provides(More)
Detection of FMCW/CW (Frequency Modulated Continuous Wave / Continuous Wave) radars is a critical problem for applying electronic counter measures. Since these radars use continuous waves with very low amplitude levels, their detection is very difficult. In this work, a new HMM (Hidden Markov Model) based track-before-detect type iterative method for(More)
Finite impulse response (FIR) filters have been a primary topic of digital signal processing since their inception. Although FIR filter design is an old problem, with the developments of fast convex solvers, convex modelling approach for FIR filter design has become an active research topic. In this work, we propose a new method based on convex programming(More)