Zaharias D. Zaharis

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—A near-optimal base-station antenna array synthesis suitable for broadcasting applications is presented. The array is required to provide a high-gain radiation pattern with a main lobe slightly tilted from the horizontal plane and null filling inside an angular sector under the main lobe. To satisfy the above requirements, a novel invasive weed(More)
—A new antenna array beamformer based on neural networks (NNs) is presented. The NN training is performed by using optimized data sets extracted by a novel invasive weed optimization (IWO) variant called modified adaptive dispersion IWO (MADIWO). The trained NN is utilized as an adaptive beamformer that makes a uniform linear antenna array steer the main(More)
A method is presented for the compression of biomedical images using in place of the discrete cosine transform (DCT) the discrete orthogonal Gauss-Hermite transform (DOGHT). The latter expands the signals on a basis of Gauss-Hermite functions instead of the cosine functions and leads, in many practical cases, to 2-3 times better compression for the same(More)
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—The Invasive Weed Optimization (IWO) is an effective evolutionary and recently developed method. Due to its better performance in comparison to other well-known optimization methods, IWO has been chosen to solve many complex non-linear problems in telecommunications and electromagnetics. In the present study, the IWO is applied to optimize the geometry of(More)
An optimal design of a linear antenna array is presented. The antenna array is optimized under the restriction of uniform excitation distribution using a particle swarm optimization based method. The optimization procedure is applied under the requirements for the minimum possible side lobe level and the maximum possible power gain at the desired direction.(More)