University of Maribor

About: University of Maribor is a education organization based out in Maribor, Slovenia. It is known for research contribution in the topics: Population & KEKB. The organization has 3987 authors who have published 13077 publications receiving 258339 citations. The organization is also known as: Univerza v Mariboru.

Resolution of the Stochastic Strategy Spatial Prisoner's Dilemma by Means of Particle Swarm Optimization

Abstract: We study the evolution of cooperation among selfish individuals in the stochastic strategy spatial prisoner's dilemma game. We equip players with the particle swarm optimization technique, and find that it may lead to highly cooperative states even if the temptations to defect are strong. The concept of particle swarm optimization was originally introduced within a simple model of social dynamics that can describe the formation of a swarm, i.e., analogous to a swarm of bees searching for a food source. Essentially, particle swarm optimization foresees changes in the velocity profile of each player, such that the best locations are targeted and eventually occupied. In our case, each player keeps track of the highest payoff attained within a local topological neighborhood and its individual highest payoff. Thus, players make use of their own memory that keeps score of the most profitable strategy in previous actions, as well as use of the knowledge gained by the swarm as a whole, to find the best available strategy for themselves and the society. Following extensive simulations of this setup, we find a significant increase in the level of cooperation for a wide range of parameters, and also a full resolution of the prisoner's dilemma. We also demonstrate extreme efficiency of the optimization algorithm when dealing with environments that strongly favor the proliferation of defection, which in turn suggests that swarming could be an important phenomenon by means of which cooperation can be sustained even under highly unfavorable conditions. We thus present an alternative way of understanding the evolution of cooperative behavior and its ubiquitous presence in nature, and we hope that this study will be inspirational for future efforts aimed in this direction.

Corrosion monitoring system based on measurement and analysis of electrochemical noise

Abstract: A corrosion monitoring system using electrochemical noise measurements and their numerical analysis was developed. Electrochemical noise was measured in a freely corroding system containin...

Measurement of e+e- →π+π-ψ (2S) via initial state radiation at Belle

Abstract: We report measurement of the cross section of e(+)e(-) -> pi(+)pi(-)psi(2S) between 4.0 and 5.5 GeV, based on an analysis of initial state radiation events in a 980 fb(-1) data sample recorded with the Belle detector. The properties of the Y(4360) and Y(4660) states are determined. Fitting the mass spectrum of pi(+)pi(-)psi(2S) with two coherent Breit-Wigner functions, we find two solutions with identical mass and width but different couplings to electron-positron pairs: M-Y(4360) = (4347 +/- 6 +/- 3) MeV/c(2), Gamma(Y(4360)) = (103 +/- 9 +/- 5) MeV, M-Y(4660) = (4652 +/- 10 +/- 8) MeV/c(2), Gamma(Y(4660)) = (68 +/- 11 +/- 1) MeV; and B[Y(4360) -> pi(+)pi(-)psi(2S)] . Gamma(e+e-)(Y(4360)) = (10.9 +/- 0.6 +/- 0.7) eV and B[Y(4660) -> pi(+)pi(-)psi(2S)] . Gamma(e+e-)(Y(4660)) = (8.1 +/- 1.1 +/- 0.5) eV for one solution; or B[Y(4360) -> pi(+)pi(-)psi(2S)] . Gamma(e+e-)(Y(4360)) = (9.2 +/- 0.6 +/- 0.6) eV and B[Y(4660) -> pi(+)pi(-)psi(2S)] . Gamma(e+e-)(Y(4660)) = (2.0 +/- 0.3 +/- 0.2) eV for the other. Here, the first errors are statistical and the second systematic. Evidence for a charged charmoniumlike structure at 4.05 GeV/c(2) is observed in the pi(+/-)psi(2S) intermediate state in the Y(4360) decays.

High resolution, all-fiber, micro-machined sensor for simultaneous measurement of refractive index and temperature

Abstract: This paper presents a highly-sensitive, miniature, all-silica, dual parameter fiber-optic Fabry-Perot sensor, which is suitable for independent measurement of the refractive index and the temperature of the fluid surrounding the sensor. The experimental sensor was produced by a micromachining process based on the selective etching of doped silica glass and a simple assembly procedure that included fiber cleaving, splicing and etching of optical fibers. The presented sensor also allows for direct compensation of the temperature’s effect on the fluid’s refractive index change and consequently provides opportunities for the detection of very small changes in the surrounding fluid’s composition. A measurement resolution of 2x10−7RIU was demonstrated experimentally for a component of the refractive index that is related purely to the fluid’s composition. This resolution was achieved under non-stabilized temperature conditions. The temperature resolution of the sensor proved to be about 10−3°C. These high resolution measurements were obtained by phase-tracking of characteristic components in a Fourier transform of sensor’s optical spectrum.