Baryon femtoscopy in heavy-ion collisions at ALICE

In this report, femtoscopic measurements with proton-proton, antiproton-antiproton, proton-antiproton, proton-antilambda, antiproton-lambda and lambda-antilambda pairs in Pb-Pb collisions at sqrt(s_NN)=2.76 TeV registered by ALICE at the LHC are presented. Emission source sizes extracted from the correlation analysis with (anti)protons grow with the event multiplicity, as expected. A method to extract the interaction potentials (e.g. for proton-antilambda and antiproton-lambda pairs) based on femtoscopy analysis is discussed. The importance of taking into account the so-called residual correlations induced by pairs contaminated by secondary particles is emphasized for all analyses mentioned above.Comment: 8 pages, 8 figures, submitted to the European Physical Journal: Web of Conferences (proceedings of ICNFP 2013 conference

Determination of the electric field gradient and the magnetic field in M\"ossbauer spectrocsopy by half-cube method

This paper presents a new method to determine all components of the electric field gradient tensor and orientation of the hyperfine magnetic field axis in the absorber Cartesian frame for M\"ossbauer spectroscopy for nuclear transitions between levels with spin 3/2 and 1/2. The method can be applied for single-crystal absorbers with well separated absorption lines in their spectra. Explicit formulas derived from velocity moments are presented. The new method allows full separation of the electric quadrupolar and magnetic dipolar hyperfine interactions by using unpolarized radiation.Comment: 6 page

C∗C^*-algebras associated to C∗C^*-correspondences and applications to mirror quantum spheres

The structure of the $C^*$-algebras corresponding to even-dimensional mirror quantum spheres is investigated. It is shown that they are isomorphic to both Cuntz-Pimsner algebras of certain $C^*$-correspondences and $C^*$-algebras of certain labelled graphs. In order to achieve this, categories of labelled graphs and $C^*$-correspondences are studied. A functor from labelled graphs to $C^*$-correspondences is constructed, such that the corresponding associated $C^*$-algebras are isomorphic. Furthermore, it is shown that $C^*$-correspondences for the mirror quantum spheres arise via a general construction of restricted direct sum.Comment: 27 page

Evolution of entanglement under an Ising-like Hamiltonian with particle losses

We present analytical compact solution for the density matrix and correlation functions of two collective-macroscopic spins evolving via Ising-like Hamiltonian in the presence of particle losses. The losses introduce non-local phase noise which destroys highly entangled states arising in the evolution. On the other hand, the states appearing at relatively short timescales, possessing EPR-like entanglement will survive. Applying our solutions to the recently proposed scheme to entangle two Bose-Einstein condensates, we estimate the optimal number of atoms for EPR correlations.Comment: 12 pages, 5 Figure

Comparative Analysis Of The Utilisation Of Electronic Commerce And Business In Polish E-shops In The Years 2009-2011

The aim of the article is to present the results of research concerning the utilisation of different aspects of electronic commerce and business in Polish e-shops, based on a number of comparative analyses performed for the years 2009-2011. Some of the presented data concern also the year 2008. The most important aspects covered by the analyses are: international trade and exports of Polish e-shops, marketing aspects of online businesses, the infrastructure and safety of Polish e-shops, their financial results, and also actions planned in order to minimise the effects of the economic crisis. The main conclusions drawn from these analyses, as well as predictions for the future for the Polish e-market, are also presented.Celem artykułu jest zaprezentowanie wyników badań dotyczących wykorzystania różnych aspektów handlu i biznesu elektronicznego w polskich e-sklepach oraz ich komparatywnej analizy wykonanej dla lat 2009-2011. Niektóre zaprezentowane dane dotyczą także roku 2008. Najważniejsze aspekty poruszane w analizach to: międzynarodowy handel i eksport polskich sklepów internetowych, aspekty marketingowe biznesu internetowego, infrastruktura i bezpieczeństwo polskich e-sklepów oraz ich wyniki finansowe, a także działania, które są planowane w celu zminimalizowania skutków kryzysu gospodarczego. W artykule zaprezentowane są również wnioski z wykonanych analiz oraz przewidywania na przyszłość dotyczące polskiego e-rynku

Wpływ barw pułapek Moerickego na liczebność i zróżnicowanie pozyskiwanych pszczół (Apoidea, Hymenoptera)

In deciduous and pine forests the effect of white, yellow and Ыие Moericke traps on numbers and sped es diversity of Apoidea was assessed. It was proven that the most useful in forest are white traps. They caught several times greater numbers of bees. The white traps caught also over 90% of all determined spedes while the yellow ones 56.4% and the blue traps only 31.6%.W lesie liściastym i sosnowym oceniono wpływ białych, żółtych i niebieskich pułapek Moerickego na liczebność i zróżnicowanie pozyskiwanych Apoidea. Wykazano, że najbardziej przydatne do odławiania Apoidea w lasach są pułapki białe. Stwierdzono kilkakrotnie wyższe liczebności pszczół odłowionych przez białe pułapki. Trafiło też do nich ponad 90% wszystkich stwierdzonych gatunków, podczas gdy do żółtych 56.4% i 31.6% do niebieskich.Zadanie pt. „Digitalizacja i udostępnienie w Cyfrowym Repozytorium Uniwersytetu Łódzkiego kolekcji czasopism naukowych wydawanych przez Uniwersytet Łódzki” nr 885/P-DUN/2014 dofinansowane zostało ze środków MNiSW w ramach działalności upowszechniającej naukę

How is a data-driven approach better than random choice in label space division for multi-label classification?

We propose using five data-driven community detection approaches from social networks to partition the label space for the task of multi-label classification as an alternative to random partitioning into equal subsets as performed by RAkELd: modularity-maximizing fastgreedy and leading eigenvector, infomap, walktrap and label propagation algorithms. We construct a label co-occurence graph (both weighted an unweighted versions) based on training data and perform community detection to partition the label set. We include Binary Relevance and Label Powerset classification methods for comparison. We use gini-index based Decision Trees as the base classifier. We compare educated approaches to label space divisions against random baselines on 12 benchmark data sets over five evaluation measures. We show that in almost all cases seven educated guess approaches are more likely to outperform RAkELd than otherwise in all measures, but Hamming Loss. We show that fastgreedy and walktrap community detection methods on weighted label co-occurence graphs are 85-92% more likely to yield better F1 scores than random partitioning. Infomap on the unweighted label co-occurence graphs is on average 90% of the times better than random paritioning in terms of Subset Accuracy and 89% when it comes to Jaccard similarity. Weighted fastgreedy is better on average than RAkELd when it comes to Hamming Loss