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Milenov T.I.,Bulgarian Academy of Science | Milenov T.I.,European Polytechnical University | Rafailov P.M.,Bulgarian Academy of Science | Tomov V.,Bulgarian Academy of Science | And 7 more authors.
Journal of Physics Condensed Matter

Single crystals of the mixed valence compound Pb3Ni 1.5Mn5.5O15 were successfully grown. Polarized Raman spectroscopy revealed that they belong to the point group D3d, in accordance with single-crystal x-ray diffraction data which were refined within the trigonal space group p3c(No.165), with lattice parameters a = 9.941(3)Å and c = 13.543(3)Å. Strongly anisotropic long range magnetic order is established below 65K. © 2011 IOP Publishing Ltd. Source

Budakova D.,Technical University of Sofia | Dakovski L.,European Polytechnical University
ICAART 2012 - Proceedings of the 4th International Conference on Agents and Artificial Intelligence

This paper investigates the social behaviour of an intelligent virtual agent (IVA) with PRE-ThINK architecture with the help of typical working student's life scenario modeling. The program system and the PRE-ThINK architecture, adapted for this scenario, are proposed, and their components are considered. The dynamics of the decision making process in problem situations caused by the implementation of this architecture is shown, when mixed emotions arise and the realization of what happened reflects on the agent's temper. IVA's social behavior is shown, during which in the process of communicating with the user the agent expresses learned from experience secondary emotions, which can be either in harmony or in conflict with the realized secondary emotions, resulting both from the agent's generalized condition and the events. The investigated secondary emotions are: relief, confidence, prestige, uncertainty, confirmed fear, disappointment; and also the socially expressed secondary emotions such as refrained sadness, refrained anger, businesslike manners, politeness and authoritativeness. Source

Dezert J.,The French Aerospace Laboratory | Tchamova A.,Bulgarian Academy of Science | Konstantinova P.,European Polytechnical University
Cybernetics and Information Technologies

The main purpose of this paper is to apply and to test the performance of a new method, based on belief functions, proposed by Dezert et al. in order to evaluate the quality of the individual association pairings provided in the optimal data association solution for improving the performances of multisensor-multitarget tracking systems. The advantages of its implementation in an illustrative realistic surveillance context, when some of the association decisions are unreliable and doubtful and lead to potentially critical mistake, are discussed. A comparison with the results obtained on the base of Generalized Data Association is made. Source

Milenov T.I.,Bulgarian Academy of Science | Milenov T.I.,European Polytechnical University | Rafailov P.M.,Bulgarian Academy of Science | Thomsen C.,TU Berlin | And 4 more authors.
Optical Materials

Crystals of BSO doped with Se in two different concentrations (BSO:Se(I) and BSO:Se(II)) were grown by the Czochralski method. It is established that doping with Se is accompanied with preferential absorption of Fe from the melt. According to the in-depth chemical analysis, it is assumed that the doping Se ions enter the tetrahedral positions by means of the substitution of 3Si 4+ by (Se6++ 2Fe3+) ions. The measured absorption spectrum of the low-concentration Se-doped crystal (BSO:Se(I)) confirms such a conclusion as the absorption coefficient is increased in a broad spectral interval (1.4-3.1 eV) - an effect typical for all Fe-doped Bi 12SiO20 crystals. The polarized Raman spectra of BSO:SeI show that the doping-induced lattice distortions are small. The IR spectrum of the BSO:SeI crystal yields indications for local lowering of the symmetry of the Fe-occupied tetrahedral positions. Doping with Se at high concentration (BSO:Se(II)) leads to occasional second phase inclusions and to a downshift of practically all modes in the Raman spectrum by 2-5.5 cm-1. It is concluded that the doping with Se at high concentrations follows the same mechanism as that at low concentrations but the introduced lattice distortions are more significant, and lead to an enlargement of the unit cell while preserving the overall cubic symmetry. © 2011 Elsevier B.V. All rights reserved. Source

Egorysheva A.V.,RAS Kurnakov Institute of General and Inorganic Chemistry | Volodin V.D.,RAS Kurnakov Institute of General and Inorganic Chemistry | Berezovskaya I.V.,Ukrainian Academy of Sciences | Zubar' E.V.,Ukrainian Academy of Sciences | And 4 more authors.
Inorganic Materials

We gave studied the crystallization behavior of 30BaO • 25Bi 2O 3 • 45B 2O 3 glasses doped with Eu 2O 3 to different levels. At a Eu 2O 3 content of 7 mol % or higher, the glasses undergo volume crystallization. The only precipitating phase is a solid solution between europium and bismuth oxides. With increasing europium concentration in the glass, the structure of the crystallites changes from cubic to rhombohedral. We have investigated the morphology, physicochemical properties, and luminescence spectra of the glasses and glass-ceramics. © 2012 Pleiades Publishing, Ltd. Source

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