Ljubljanska izjava

Ljubljanska izjava o rabi slovenskega jezika v visokošolskih ustanovah v Sloveniji z namenom ohranjanja jezikovne raznolikosti v Evropski unij

A quadratic lower bound for subset sums

Let A be a finite nonempty subset of an additive abelian group G, and let \Sigma(A) denote the set of all group elements representable as a sum of some subset of A. We prove that |\Sigma(A)| >= |H| + 1/64 |A H|^2 where H is the stabilizer of \Sigma(A). Our result implies that \Sigma(A) = Z/nZ for every set A of units of Z/nZ with |A| >= 8 \sqrt{n}. This consequence was first proved by Erd\H{o}s and Heilbronn for n prime, and by Vu (with a weaker constant) for general n.Comment: 12 page

Warburton, N. (2012). Vprasanje umetnosti [The art question]. Afterword study by Marjan Simenc. Ljubljana: Sophia. [Book review]

Book review of: Warburton, N. (2012). Vprasanje umetnosti [The art question]. Afterword study by Marjan Simenc. Ljubljana: Sophia. 158 p., ISBN 978-961-6768-48-1

27th European Congress of Arachnology, Ljubljana, Slovenia, 2 - 7 September 2012

Recently 157 participants from 39 countries met in Ljubljana, Slovenia, for presenting, discussing and sharing arachnological topics. This was the 27th European Congress of Arachnology, held from the 2nd to 7th of September 2012

Transport in tunnelling recombination junctions: a combined computer simulation study

The implementation of trap-assisted tunneling of charge carriers into numerical simulators ASPIN and D-AMPS is briefly described. Important modeling details are highlighted and compared. In spite of the considerable differences in both approaches, the problems encountered and their solutions are surprisingly similar. Simulation results obtained for several tunneling recombination junctions made of amorphous silicon (a-Si), amorphous silicon carbide (a-SiC), or microcrystalline silicon (µc-Si) are analyzed. Identical conclusions can be drawn using either of the simulators. Realistic performances of a-Si/a-Si tandem solar cells can be reproduced with simulation programs by assuming that extended-state mobility increases exponentially with the electric field. The same field-enhanced mobilities are needed in single tunneling recombination junctions in order to achieve measured current levels. Temperature dependence of the current-voltage characteristics indicates that the activation energy of enhanced mobilities should be determined. Apparent discrepancies between simulation results and measurements are explained and eliminated making use of Gill’s law. For application in tandem and triple solar cell structures, tunneling recombination junctions made of (µc-Si) are the most promising of all examined structures.Fil: Vukadinovic, M.. University of Ljubljana; EsloveniaFil: Smole, F.. University of Ljubljana; EsloveniaFil: Topič, M.. University of Ljubljana; EsloveniaFil: Schropp, R. E. .. Utrecht University; Países BajosFil: Rubinelli, Francisco Alberto. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Desarrollo Tecnológico para la Industria Química. Universidad Nacional del Litoral. Instituto de Desarrollo Tecnológico para la Industria Química; Argentin

Top Quark Properties

Recent measurements of top-quark properties at the LHC and at the Tevatron are presented. The results include precision measurements of standard model parameters, such as the top-quark mass, the measurement of angular distributions as well as the search for anomalous couplings.Comment: Conference proceedings for Lepton Photon, Ljubljana, 17-22 August 2015, 12 pages, 10 figure