Hristos T. Anastassiu

Prof. Hristos T. Anastassiu

CIT Engineering, International Hellenic University, Thessaloníki, Kentrikí Makedonía, Greece
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Research Focus & Metrics

Academic Career Length

31Years (1996-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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1 July 2021 in Composites Part B: Engineering
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ASApostolos Sotiropoulos
Apostolos Sotiropoulos
Stavros KoulouridisStavros Koulouridis
Stavros Koulouridis
AMAthanasios Masouras
Athanasios Masouras
VKVasilis Kostopoulos
Vasilis Kostopoulos
Hristos T. AnastassiuHristos T. Anastassiu
Hristos T. Anastassiu

17 May 2022 in Technologies
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EPEvridiki Papachristou
Evridiki Papachristou
Hristos T. AnastassiuHristos T. Anastassiu
Hristos T. Anastassiu
A very large number of scientific papers have been published in the literature on wearable antennas of several types, structure and functionality. The main focus is always antenna efficiency from an engineering point of view. However, antenna integration into actual, realistic garments is seldom addressed. In this paper, 2D pattern and 3D virtual prototyping technology is utilized to develop regular clothing, available in the market, in which wearable antennas are incorporated in an automated manner, reducing the chances of compromising the garment elegance or comfort. The functionality of various commercial software modules is described, and particular design examples are implemented, proving the efficiency of the procedure and leading the way for more complex configurations.

12 March 2014 in Sensors
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Hristos T. AnastassiuHristos T. Anastassiu
Hristos T. Anastassiu
Stavros VougioukasStavros Vougioukas
Stavros Vougioukas
TFTheodoros Fronimos
Theodoros Fronimos
CRChristian Regen
Christian Regen
LPLoukas Petrou
Loukas Petrou
JKJana Käthner
Jana Käthner
A computational model for radio wave propagation through tree orchards is presented. Trees are modeled as collections of branches, geometrically approximated by cylinders, whose dimensions are determined on the basis of measurements in a cherry orchard. Tree canopies are modeled as dielectric spheres of appropriate size. A single row of trees was modeled by creating copies of a representative tree model positioned on top of a rectangular, lossy dielectric slab that simulated the ground. The complete scattering model, including soil and trees, enhanced by periodicity conditions corresponding to the array, was characterized via a commercial computational software tool for simulating the wave propagation by means of the Finite Element Method. The attenuation of the simulated signal was compared to measurements taken in the cherry orchard, using two ZigBee receiver-transmitter modules. Near the top of the tree canopies (at 3 m), the predicted attenuation was close to the measured one—just slightly underestimated. However, at 1.5 m the solver underestimated the measured attenuation significantly, especially when leaves were present and, as distances grew longer. This suggests that the effects of scattering from neighboring tree rows need to be incorporated into the model. However, complex geometries result in ill conditioned linear systems that affect the solver’s convergence.

28 October 2004 in Radio Science
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Hristos T. AnastassiuHristos T. Anastassiu
Hristos T. Anastassiu
DKDimitria I. Kaklamani
Dimitria I. Kaklamani

4 September 2024 in Electronics
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PPPANAGIOTIS PAPAKANELLOS
PANAGIOTIS PAPAKANELLOS
Nikolaos TsitsasNikolaos Tsitsas
Nikolaos Tsitsas
Hristos T. AnastassiuHristos T. Anastassiu
Hristos T. Anastassiu
This paper presents a comprehensive review of research conducted on the Method of Auxiliary Sources (MAS) over a period of the last 22 years, i.e., since the last up-to-date survey was published. MAS is a very attractive numerical technique due to its simple algorithmic structure and the generally low computational cost it requires in terms of memory and CPU time; this is why it has been applied to a vast variety of cases, as concluded by the long citations list included. After a short introduction summarizing the fundamental concepts of the method, references since 2002 are categorized, briefly described, and commented on. This work is intended to assist every researcher who is involved in MAS computations, providing an exhaustive, to the best of the authors’ knowledge, list of related publications.

5 September 2022 in Mathematics
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EMEleftherios Mastorakis
Eleftherios Mastorakis
PPPANAGIOTIS PAPAKANELLOS
PANAGIOTIS PAPAKANELLOS
Hristos T. AnastassiuHristos T. Anastassiu
Hristos T. Anastassiu
Nikolaos TsitsasNikolaos Tsitsas
Nikolaos Tsitsas
The Method of Auxiliary Sources (MAS) is an established technique for the numerical solution of electromagnetic (EM) scattering and radiation problems. This paper presents a hybrid of MAS with the Fast Multipole Method (FMM), which provides a strategy for reducing the computational cost and for solving large-scale problems without notable accuracy loss (and in a reasonable time). The hybrid MAS-FMM scheme is applied to the problem of EM scattering from an arbitrarily large array of lossless/lossy dielectric cylinders. Numerical results are presented to verify the MAS and MAS-FMM schemes, as well as to illuminate the improvements stemming from the proposed hybridization (especially the ones regarding the associated complexity and computational cost). A few concluding remarks offer a summary of this work, along with a list of possible future extensions.