# Ioannis P. AntoniadesAristotle University of Thessaloniki | AUTH · School of Physics

Ioannis P. Antoniades

Doctor of Philosophy

## About

30

Publications

2,982

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180

Citations

Introduction

My current research activity focuses on modeling, simulation and analysis of complex & chaotic systems from an interdisciplinary point of view, concentrating on diverse applications in alloys and semiconductors and in nano-electronics, economics, social systems, secure communications and biophysics by employing methods such as ODEs, non-linear analysis, non-extensive statistics, complex networks, reservoir computing, deep neural nets as well as atomistic (Monte Carlo or MD) simulations.

## Publications

Publications (30)

We perform non-linear analysis on stock market indices using time-dependent extended Tsallis statistics. Specifically, we evaluate the q-triplet for particular time periods withthe purpose of demonstrating the temporal dependence of the extended characteristicsoftheunderlyingmarketdynamics.Weapplytheanalysisondaily close price time series of four m...

In this work we present a thorough investigation of the effect of noise (internal or external) on the synchronization of a drive-response configuration system (unidirectional coupling between two identical systems). Moreover, since in every practical implementation of a communication system, the transmitter and receiver circuits (although identical...

The present paper presents a first attempt to produce a dynamical simulation model for the development process of open source software projects. First, a general framework for such models is introduced. Then, a specific simulation model is described and demonstrated. The model equations are based on available literature case studies whenever possib...

We derive a mean field equation for a [001] twist grain boundary. For the description of the one-site probability function we use the coincident-site lattice symmetry and the displacement shift complete lattice with two order parameters: one corresponding to the direction of the coincident-site lattice supercell lattice vector and one to the [001]...

This software implements the procedure and algorithm prescribed in
[1]. "The use of scaling properties to detect relevant changes in financial time series: A new visual warning tool", I.P. Antoniades, Giuseppe Brandi, L. Magafas, T.Di Matteo, Physica A, 565 (2021), DOI: 10.1016/j.physa.2020.125561.
to calculate and plot Temporal Patterns (TP) for...

The dynamical electric behavior of a NiTi smart alloy thin filament when driven by time varying current pulses is studied by a structure-based phenomenological model that includes rate-based effects. The simulation model relates the alloy's electrical resistivity to the relative proportions of the three main structural phases namely Martensite, Aus...

The dynamical electric behavior of a NiTi smart alloy thin filament when driven by time varying current pulses is studied by a structure-based phenomenological model that includes rate-based effects. The simulation model relates the alloy's electrical resistivity to the relative proportions of the three main structural phases namely Martensite, Aus...

We perform non-linear analysis on stock market indices using time-dependent extended Tsallis statistics. Specifically, we evaluate the q-triplet for particular time periods with the purpose of demonstrating the temporal dependence of the extended characteristics of the underlying market dynamics. We apply the analysis on daily close price timeserie...

The dynamical evolution of multiscaling in financial time series is investigated using time-dependent Generalized Hurst Exponents (GHE), Hq, for various values of the parameter q. Using Hq, we introduce a new visual methodology to algorithmically detect critical changes in the scaling of the underlying complex time-series. The methodology involves...

The dynamical evolution of multiscaling in financial time series is investigated using time-dependent Generalized Hurst Exponents (GHE), $H_q$, for various values of the parameter $q$. Using $H_q$, we introduce a new visual methodology to algorithmically detect critical changes in the scaling of the underlying complex time-series. The methodology i...

Timeseries produced by a idealized macroeconomic model are analyzed by means of conversion to complex networks by three different methods: the re-cursive graph method, the natural visibility graph method and the ordinal partition graph method. For several values of one of the model's control parameters yielding both fully chaotic time-series and in...

In this study Tsallis non-extensive statistics and multifractal analysis for the physical description and understanding of the Random Telegraph Noise (RTN), observed in UTBB FD-SOI MOSFET current timeseries is presented. Specifically, we estimate the Tsallis q-triplet and q-entropy production, the Hurst exponent, the multifractal singular
spectrum...

In this paper, the experimental study and confirmation of the memristive behavior demonstrated by nanowires made of a smart alloy, namely NiTi, are presented. Further contribution to the characterization of the proposed novel NiTi memristor, included measurements in the ac domain, confirming the memristive nature of these NiTi wires/devices. These...

Data stream coder based on chaotic synchronous response is considered. An estimate of the number of keys available in this scheme is obtained by cascading the basic building block of the system and thus repeating the encoding procedures. Efficiency of the discussed algorithm (in the sense of computational expenses) is evaluated and compared to know...

One important question in FLOSS is whether and to what extent open source information systems are of
higher quality than their proprietary counterparts. A second question raised is what to define as information
systems quality. This question becomes more pertinent when it comes to enterprise systems such as the ERP and CRM ones. This paper implemen...

The nonlinear behaviour of an R–L-Varactor circuit, simulated by Multisim 7.0 at a driving frequency that is below the circuit resonance frequency, is reported and evaluated. A new high amplitude oscillation is observed and attributed to the emergence of a large diode junction capacitance. Increasing the driving signal amplitude, the circuit is led...

We present the implementation of a chaotic communication system with enhanced security features. The enhancement in the security of the system at hand is achieved neither by increasing chaos dimensionality nor by making synchronization of transmitter and receiver more sensitive to system parameters but by introducing a set of parameters used in the...

Polycrystalline silicon obtained by the crystallization of thin amorphous silicon films has been an important material for microelectronics technology during the last decades. Many properties are improved in crystallized amorphous silicon compared to the as-deposited polysilicon such as larger grain size, smoother surface, and higher-carrier mobili...

Quantum Cryptography is assumed as a next generation crypto-graphic system that may replace the public key protocol. The advantage of quantum cryptography over traditional key exchange methods is that the ex-change of information can be shown to be secure in a very strong sense, with-out making assumptions about the intractability of certain mathem...

In this paper we present the functional design of a resource arbiter based on Neural Networks. The decision for the access of the shared resource is based on a multilevel hierarchical Neural Network. The arbitration is based on a winner-take-all scheme and the priority measures are distributed in the neural network's adaptive weights. The system is...

This chapter will discuss attempts to produce formal mathematical models for dynamical simulation of the development process of Free/Open Source Software (F/OSS) projects. First, a brief overview for simulation methods of closed source software development is given. Then, based on empirical facts reported in F/OSS case studies, we describe a genera...

In this paper we present a technique using feedforward neural nets to treat some types of noise frequently encountered in experimental measurements. We show that these neural nets act as inherent filters in lineshapes contaminated with noise, and propose solutions that could be implemented online to smooth the curves of interest. This method works...

This chapter will discuss attempts to produce formal mathematical models for dynamical simulation of the development process of Free/Open Source Software (F/OSS) projects. First, a brief overview for simulation methods of closed source software development is given. Then, based on empirical facts reported in F/OSS case studies, we describe a genera...

This paper presents a short review of theoretical developments in Quantum Cryptography, a field that has attracted significant attention and multi-disciplinary scientific effort mainly in the past ten years. Since its birth (about two decades ago) advances in Quantum Cryptography have yielded important results from a conceptual as well as practical...

We derive a mean field equation for a [001] twist grain boundary. For the description of the one-site probability function we use the CSL symmetry and the DSC lattice with two order parameters one corresponding to the direction of the CSL supercell lattice vector and one to direction [001] (normal to boundary). We then present a new analytical meth...

We address the problem of the controversial energy cusp around the [001] Σ5 twist grain boundary in a binary alloy system (Cu3Au) using a molecular dynamics approach. We find a definite cusp at Σ5 which is, however, much shallower than previous simulation results in single metal Cu, Au [001] twists. A Read-Shockley type formula by Vitek does not fi...

Sixteen [001] twist boundaries in Cu3Au spanning a wide range of misorientation angles are investigated at T=0 K using the molecular dynamics and Monte Carlo techniques within the framework of the coincident site lattice approach. Grain boundary (GB) energies vary smoothly with misorientation angle and are described satisfactorily by formulas deriv...

## Questions

Question (1)

In Voltage Controlled Magnetic Anisotropy (VCMA) of a nanomagnet, one needs an ultrathin ferromagnetic layer attached to a dielectric like MgO. In order to deterministically switch the magnetization from in plane to out-of-plane and vice-versa (i.e by 90 degrees) by a change of the voltage applied between two electrodes sandwitching the ferromagnet+dielectric layers ,

**is an additional external magnetic field required?**If yes, does the direction of the external magnetic field have to be perpendicular to the plane of the nanomagnet or parallel to it? Note that I want only a 90o switching NOT a complete reversal (180o).## Projects

Projects (5)

NiTi belongs to the broad class of smart materials and is best known for its remarkable thermoelastic properties, particularly for its "memory" effect, i.e. its ability to "recall" its initial shape when heated after it has been plastically deformed.
Apart from its peculiar thermo-mechanical properties, NiTi also displays interesting electrical behavior and it has been shown to behave as an extended memristor, the well-known 4th basic electrical element.
In this project we study NiTi electrical properties under DC or AC (time-varying) currents both experimentally as well as by theoretical modeling and simulation.

This projects aims to look into the temporal evolution of scaling but also any other metric that depends of financial time-series (macro-economical, stock market etc,). The purpose is to detect relevant temporal changes in the metric that can be used, for example, as warning/signaling tool for future events.