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.

Growth and structure of Slovenia's scientific collaboration network

Abstract: We study the evolution of Slovenia's scientific collaboration network from 1960 till present with a yearly resolution. For each year the network was constructed from publication records of Slovene scientists, whereby two were connected if, up to the given year inclusive, they have coauthored at least one paper together. Starting with no more than 30 scientists with an average of 1.5 collaborators in the year 1960, the network to date consists of 7380 individuals that, on average, have 10.7 collaborators. We show that, in spite of the broad myriad of research fields covered, the networks form "small worlds" and that indeed the average path between any pair of scientists scales logarithmically with size after the largest component becomes large enough. Moreover, we show that the network growth is governed by near-liner preferential attachment, giving rise to a log-normal distribution of collaborators per author, and that the average starting year is roughly inversely proportional to the number of collaborators eventually acquired. Understandably, not all that became active early have till now gathered many collaborators. We also give results for the clustering coefficient and the diameter of the network over time, and compare our conclusions with those reported previously.

Study of double charmonium production in e + e - annihilation at √(s)≈10.6 GeV

Abstract: We present a new analysis of double charmonium production in ${e}^{+}{e}^{\ensuremath{-}}$ annihilation. The observation of the processes ${e}^{+}{e}^{\ensuremath{-}}\ensuremath{\rightarrow}J/\ensuremath{\psi}{\ensuremath{\eta}}_{c}$, $J/\ensuremath{\psi}{\ensuremath{\chi}}_{c0}$, and $J/\ensuremath{\psi}{\ensuremath{\eta}}_{c}(2S)$ is confirmed using a data set more than 3 times larger than that of Belle's previous report, and no evidence for the process ${e}^{+}{e}^{\ensuremath{-}}\ensuremath{\rightarrow}J/\ensuremath{\psi}J/\ensuremath{\psi}$ is found. We perform an angular analysis for $J/\ensuremath{\psi}{\ensuremath{\eta}}_{c}$ production and set an upper limit on the production of $J/\ensuremath{\psi}J/\ensuremath{\psi}$. Processes of the type ${e}^{+}{e}^{\ensuremath{-}}\ensuremath{\rightarrow}\ensuremath{\psi}(2S)(c\overline{c}{)}_{\mathrm{r}\mathrm{e}\mathrm{s}}$ have been observed for the first time; their rates are found to be comparable to those of ${e}^{+}{e}^{\ensuremath{-}}\ensuremath{\rightarrow}J/\ensuremath{\psi}(c\overline{c}{)}_{\mathrm{r}\mathrm{e}\mathrm{s}}$ processes.

Memetic firefly algorithm for combinatorial optimization

Abstract: Firefly algorithms belong to modern meta-heuristic algorithms inspired by nature that can be successfully applied to continuous optimization problems. In this paper, we have been applied the firefly algorithm, hybridized with local search heuristic, to combinatorial optimization problems, where we use graph 3-coloring problems as test benchmarks. The results of the proposed memetic firefly algorithm (MFFA) were compared with the results of the Hybrid Evolutionary Algorithm (HEA), Tabucol, and the evolutionary algorithm with SAW method (EA-SAW) by coloring the suite of medium-scaled random graphs (graphs with 500 vertices) generated using the Culberson random graph generator. The results of firefly algorithm were very promising and showed a potential that this algorithm could successfully be applied in near future to the other combinatorial optimization problems as well.