A5004246635- Theoretical and Computational Physics
- Stochastic processes and statistical mechanics
- Complex Network Analysis Techniques
- Spectroscopy and Quantum Chemical Studies
- Opinion Dynamics and Social Influence
- Material Dynamics and Properties
- Diffusion and Search Dynamics
- Complex Systems and Time Series Analysis
- Advanced Thermodynamics and Statistical Mechanics
- Photochemistry and Electron Transfer Studies
- Advanced Chemical Physics Studies
- nanoparticles nucleation surface interactions
- stochastic dynamics and bifurcation
- Drug Solubulity and Delivery Systems
- Molecular Junctions and Nanostructures
- Neural Networks and Applications
- Random Matrices and Applications
- Statistical Mechanics and Entropy
- Neural dynamics and brain function
- Gene Regulatory Network Analysis
- Advanced Drug Delivery Systems
- Quantum chaos and dynamical systems
- Random lasers and scattering media
- Nonlinear Dynamics and Pattern Formation
- Electron Spin Resonance Studies
Aristotle University of Thessaloniki
2014-2023
International Hellenic University
2021
University of Macedonia
2003-2019
University of Michigan
1993-2013
University of Manchester
2005
P.N. Lebedev Physical Institute of the Russian Academy of Sciences
2000
KU Leuven
2000
Bulgarian Academy of Sciences
1993-1998
Universidade de Vigo
1996
Forschungszentrum Jülich
1995
We study tolerance and topology of random scale-free networks under attack defense strategies that depend on the degree $k$ nodes. This situation occurs, for example, when robustness a node depends its or in an intentional with insufficient knowledge network. determine, all strategies, critical fraction ${p}_{c}$ nodes must be removed disintegrating find that, attack, little well-connected sites is sufficient to strongly reduce ${p}_{c}$. At criticality, network removal strategy, implying...
We have re-examined the random release of particles from fractal polymer matrices using Monte Carlo simulations, a problem originally studied by Bunde et al. [J. Chem. Phys. 83, 5909 (1985)]. A certain population diffuses on structure, and as reach boundaries structure they are removed system. find that number escape matrix function time can be approximated Weibull (stretched exponential) function, similar to case Euclidean matrices. The earlier result rates described power laws is correct...
We introduce an immunization method where the percentage of required vaccinations for immunity are close to optimal value a targeted scheme highest degree nodes. Our strategy retains advantage being purely local, without need knowledge on global network structure or identification The consists selecting random node and asking neighbor that has more links than himself given threshold immunizing him. compare this other efficient strategies three real social networks scale-free model find it be...
We model the spreading of a crisis by constructing global economic network and applying Susceptible-Infected-Recovered (SIR) epidemic with variable probability infection. The infection depends on strength relations between pair countries, target country. It is expected that which originates in large country, such as USA, has potential to spread globally, like recent crisis. Surprisingly we show also countries much lower GDP, Belgium, are able initiate Using {\it k}-shell decomposition method...
We show that the chemical reactions of model systems $A+A\ensuremath{\rightarrow}0$ and $A+B\ensuremath{\rightarrow}0$ when performed on scale-free networks exhibit drastically different behavior as compared to same in normal spaces. The exponents characterizing density evolution a function time are considerably higher than 1, implying both occur at much faster rate. This is due fact discerning effects generation depletion zone ($A+A$) segregation reactants ($A+B$) do not all Instead we...
We investigate the trapping problem in Erdős-Rényi (ER) and scale-free (SF) networks. calculate evolution of particle density ρ(t) random walkers presence one or multiple traps with concentration c. show using theory simulations that ER networks, while for short times ρ(t)∝exp(-Act), longer exhibits a more complex behavior, explicit dependence on both number size network. In SF networks we reveal significant impact trap's location: is drastically different when trap placed node compared to...
Random-walk simulations at and above the percolation threshold were performed for two- three-dimensional lattices. The number of distinct sites visited on percolating cluster obeys "superuniversality" relation, showing a fractal spectral (fracton) dimensionality $\frac{4}{3}$. We also observe fractal-to-Euclidean crossovers with time increased concentration (above threshold). mean-squared displacement (from origin) shows similar behavior its critical exponents are compared previous work.
A microscopic transport theory is developed for stochastic and correlated hopping on ordered random lattices that contain a small fraction of supertraps number ’’hoppers’’ (i.e., excitons). It includes short-time (’’transient’’) behavior, which interest both time-resolved steady-state experiments. The relations with diffusion, percolation, walk, rate equations are exhibited applications to energy in disordered molecular aggregates illustrate the approach, combination rigorous analytical...
We report the critical point for site percolation ``explosive'' type two-dimensional square lattices using Monte Carlo simulations and compare it to classical well-known percolation. use similar algorithms as have been recently reported bond networks. calculate explosive threshold ${p}_{c}=0.695$ we find evidence that surprisingly may belong a different universality class than on lattices, providing transitions (a) are continuous (b) obey conventional finite size scaling forms. Finally,...
Monte Carlo simulation of transient, diffusion-controlled annihilation (A+A\ensuremath{\rightarrow}0) and fusion (A+A\ensuremath{\rightarrow}A) reactions have been performed on one- two-dimensional lattices the fractal, critical percolation cluster a square lattice (applying breadth-first search algorithm). Fast self-ordering is demonstrated via analyses interparticle distributions nearest-neighbor distance (NNDD). Good agreement obtained with few existing analytical results in one...
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTStirring in chemical reactionsPanos Argyrakis and Raoul KopelmanCite this: J. Phys. Chem. 1989, 93, 1, 225–229Publication Date (Print):January 1989Publication History Published online1 May 2002Published inissue 1 January 1989https://pubs.acs.org/doi/10.1021/j100338a048https://doi.org/10.1021/j100338a048research-articleACS PublicationsRequest reuse permissionsArticle Views323Altmetric-Citations44LEARN ABOUT THESE METRICSArticle Views are the...
The Living Earth Simulator (LES) is one of the core components FuturICT architecture. It will work as a federation methods, tools, techniques and facilities supporting all simulation-related activities to allow encourage interactive exploration understanding societal issues. Society-relevant problems be targeted by leaning on approaches based complex systems theories data science in tight interaction with other FuturICT. LES evaluate provide answers real-world questions taking into account...
We compare reaction-diffusion processes of the $A+A\to 0$ type on scale-free networks created with either configuration model or uncorrelated model. show via simulations that except for difference in behavior two models, different results are observed within same when minimum number connections a node varies from $k_{\rm min}=1$ to min}=2$. This is attributed varying local properties systems. In all cases we able identify power law density decay time an exponent $f>1$, considerably larger...
Simulations of random walkers on two-dimensional (square lattice) percolation clusters were performed for a range occupation probabilities from critical to unity. The number distinct sites visited, over 2×105 steps, shows the conjectured scaling, crossover and superuniversaility (ds=4/3, within 1%) behavior wide site probabilities. Possible deviations superuniversality and/or scaling are discussed.
Monte Carlo simulations of transient, diffusion-controlled A+B\ensuremath{\rightarrow}0 reactions are performed on one-, two-, and three-dimensional Euclidean lattices a fractal lattice (two-dimensional critical percolation cluster). The particle distributions analyzed by partial nearest-neighbor distance (NNDD), taxicab NNDD, linearized NNDD. Comparisons made with NNDD interparticle the A+A\ensuremath{\rightarrow}0 A+A\ensuremath{\rightarrow}A (extending some preceding paper [Phys. Rev. A...