|Archive of LIT seminars (2010)|
|December 23, 2010, at 15.00 ( LIT, r.407 ) the seminar LIT will be held: |
1. Alexey Stavtsev (RUPF): "Mathematical modeling of the laser radiation scattering in three-layer irregular waveguide"
In the present report the methods and algorithms permitting to calculate fields for various directed, radiant and leaky TE and TM modes of symmetrical and
asymmetrical integrated-optical waveguides are presented. The description of the theoretical approaches and algorithm of calculation of the field of a scattered
radiation outside of an irregular integrated-optical waveguide in the system of visual programming Delphi is given. The results of numerical experiments of the
calculation of the dispersion dependences for TE and TM modes of both direct and leaky modes for the regular planar integrated optical waveguide, profiles of
radiative fields of the TE modes of the substrate layer and fields of electromagnetic radiation scattered in an integrated-optical waveguide with three-dimensional
irregularities are also given.
2. Alexey Khokhlov (RUPF): "Modeling of diffraction of a linearly polarized light on the multilayer thin film coatings"
The problem of modeling of normal electromagnetic wave of optical range in homogeneous isotropic and anisotropic media is considered. The methods of simulation
of multilayer optical systems, the characteristic dimensions are comparable with the wavelength of light, are presented. The diffraction of normal optical range of
electromagnetic wave on a dielectric one-dimensional diffraction grating for cases of TE and TM polarization of the incident wave is considered. We discuss the specifics
of the Modal Fourier Method and the Rayleigh Hypothesis for binary gratings in the case of TM polarization. A stable computer implementation of the Fourier Modal Method
and examples of calculations are presented.
|December 23, 2010, at 11.00 ( LIT, r.407 ) the seminar LIT will be held: |
I. Filozova, V. Borisovski, S. Kouniaev, G. Musulmanbekov, R. Semenov, G. Shestakova, P. Ustenko, T. Zaikina:
"OAI repository for scientific publications of JINR researchers"
In the framework of the international program OAI the electronic open access archive-repository JINR Document Server (JDS) is built up.
The main documents downloaded in JDS are publications of JINR researchers. As software for build up and support of JDS the CDS Invenio package,
elaborated in CERN, has been chosen. CDS Invenio is an integrated digital library system with an environment and tools for building and maintenance of
digital library servers. Document sources for JDS are the worldwide known archive ‘arXiv.org’, search servers ‘SPIRES’ and ‘MathSciNet’, JINR information
base PIN and self-archiving.
|December 21, 2010, at 15.00 ( LIT, r.406 ) the seminar LIT will be held: |
I.M. Gostev: "About the metrics invariant to the group of projective transformations"
The report discusses the principles of constructing the metrics that are applied for recognition of the geometric form
of graphic objects invariant to their projective images.
|November 23, 2010, at 15.00 ( LIT, r.407 ) the seminar LIT will be held: |
D.V. Belyakov, I.M. Gostev, N.A. Davydova, L.A.Kalmykova,
"DoctorDoc Information System of the Electronic Document Circulation"
|November 18, 2010, at 15.00 ( LIT, r.407 ) the seminar LIT will be held: |
Anirudh Pradhan (Department of Mathematics, Hindu Post-graduate College, Zamania-232 331, Ghazipur, India; LIT, JINR, Dubna, Russia),
Hassan Amirhashchi (Department of Physics, Islamic Azad University, Mahshahr Branch, Mahshahr, Iran),
Bijan Saha (LIT, JINR, Dubna, Russia):
"Anisotropic Dark Energy Models"
The Wilkinson Microwave Anisotropy Probe (WMAP) satellite experiment suggests 73% content of the Universe in the form of dark energy,
23% in the form of non-baryonic dark matter and the rest 4% in the form of usual baryonic matter as well as radiation. Lots of candidates to represent dark energy
(viz. cosmological constant, vacuum energy, scalar field, brane world, cosmological nuclear energy etc.) have been constructed and confronted with observations.
At present, there is a great interest in cosmological models with a variable equation of state (EoS), which is also a possible suspect for dark energy.
New dark energy models in anisotropic space-time with variable equation of state (EoS) parameter have been investigated. The Eos for dark energy is found to be
time dependent and its existing range for these models is in good agreement with the recent observations of Supernova type Ia (SNe Ia) data (Knop et al. 2003),
SNe Ia data with Cosmic Microwave Background Radiation (CMBR) anisotropy galaxy clustering statistics (Tegmark et al. 2004) and latest a combination of cosmological
datasets coming from CMB anisotropies, luminosity distances of high red-shift type Ia supernova and galaxy clustering (Hinshaw et al . 2009, Komatsu et al. 2009).
The cosmological constant is found to be a positive decreasing function of time and it approaches a small positive value at late time (i.e., at present epoch) which is
corroborated by results from recent supernova Ia observations. The physical aspects of the models are also discussed in detail.
|September 28, 2010, at 15.00 ( LIT, r.310 ) the seminar LIT will be held: |
Vladimir Todorov Dimitrov (Sofia University): "Problems in the specification of the business processes semantics"
|September 17, 2010, at 12.00 ( LIT Conference Hall ) the seminar LIT will be held: |
Scientific and historical memorial seminar dedicated to M.G. Mescheryakov's 100th anniversary.
Programme of events.
|September 02, 2010, at 14.00 ( LIT, r.310 ) the seminar LIT will be held: |
A.V. Korolkova (Russian University of People's Friendship): "Mathematical model of a traffic transfer process with the dynamical intensity of the
stream regulated by a RED-type algorithm"
(Materials of a PhD thesis)
|August 26, 2010, at 11.00 ( LIT, r.310 ) the seminar LIT will be held: |
Csaba Torok: "On selecting join parameters of segments in piecewise polynomial smoothin"
We present a new approach to piecewise parametric smoothing of noisy data with
complex structure based on an Akaike-type criterion and shared parameters.
|August 25, 2010, at 11.00 ( LIT, r.310 ) the seminar LIT will be held: |
S.A. Lebedev: "Algorithm and software for cherenkov ring reconstruction and electron identification in the RICH detector of the CBM experiment"
(Materials of Master’s Thesis)
|August 05, 2010, at 15.00 ( LIT, r.310 ) the seminar LIT will be held: |
P.H. Atanasova, E.V. Zemlyanaya, Yu.M. Shukrinov: "Numerical analysis of the LJJ model accounting the second harmonic in the Josephson current
We consider a mathematical model of the static magnetic flux distributions in the long Josephson junctions (LJJ) taking into account the second
harmonic in the decomposition of the Josephson current. Main solutions the have been found. Stability of magnetic flux distributions has been investigated.
We observe that the second harmonic contribution changes properties of solutions that are known in the traditional model. New stable states
are shown to be appearing.
|July 28, 2010, at 11.00 ( LIT, r.310 ) the seminar LIT will be held: |
А.А. Лебедев: "Алгоритмы и программное обеспечение для реконструкции треков в детекторе переходного излучения и в мюонной
системе эксперимента СВМ" (по материалам кандидатской диссертации)
|July 09, 2010, at 15.00 ( LIT, r.310 ) the seminar LIT will be held: |
Владимир Димитров, Василь Георгиев (Софийский университет): "Исследования, проекты и обучение
в области распределенной обработки информации в Софийском университете"
|April 01, 2010, at 11.00 ( LIT, r. 310 ) the seminar LIT will be held: |
Yu.L. Kalinovsky: " Effective QCD at finite temperature and density" (Materials of Doctoral Thesis)
An effective model for the description of hadron physics at low energy on the assumption of the basic QCD principles and the separable interaction is considered. It has been shown that the separable approach to the choice of the nucleus interaction allows one to build a quark propagator in a phenomenological way, to solve numerically the Bethe-Salpeter equation and to describe the behaviour of both light and heavy mesons. For the local separable interaction, a generalization is carried out for a case of finite temperature and density of the nuclear matter. It is demonstrated that all low energy theorems are fulfilled, complete investigation of the behaviour of the symmetry violation is performed, phase transitions are considered and critical exponents are calculated.
|March 18, 2010, at 15.00 ( LIT Conference hall, 5 th Floo ) the seminar LIT will be held: |
the Memorial seminar :is devoted to the 80th anniversary of N.N. Govorun's
|February 15, 2010, at 11.00 ( LIT, r. 310 ) the seminar LIT will be held: |
A.S. Gevorkyan: "New Algorithms for High Performance Computations"
1. The problem of 3D reactive scattering in the three-bodies system.
The quantum 3D reactive scattering theory is developed in the framework of natural collision coordinates. It is shown that the quantum scattering processes fully are described by the system of ordinary differential equations of second-order. In work two algorithms of numerical simulation of these equations are discussed. The idea of the first algorithm consists in the following. With the help of integral transformation the initial system of equations is reduced to the Koshi problem for the ordinary integral-differential equations of first order. It is shown that this system of equations on a grid of points of coordinate reaction is reduced into the system of linear ordinary differential equations of first order, which can be simulated with the help of standard programs BLAS or LaPack. The second scheme of simulation of problem is proposed on the basis of Runge-Kutta method of 4th order. In this case also the system of integral-differential equations of first order is used and the computations are conducted by iterative method.
2. The statistical and dynamical properties of spin-glass system under the influence of external fields.
The dielectric medium consisting of rigidly polarized molecules is treated as a 3D disordered spin system. For investigation of statistical and dynamical properties of this system on scales of space-time periods of standing electromagnetic wave a microscopic approach is developed. Using Birgoff’s ergodic hypothesis the initial 3D spin-glass problem is reduced to two conditionally separated 1D problems along the external electromagnetic field's propagation. It is shown that the first problem describes a quantum dynamics of 1D disordered N-particles system with relaxation in 3D medium, while the second one consists in investigation of statistical properties of ensemble of disordered steric 1D spin-chain with environment. Both problems are investigated in detail. All necessary equations for calculation of coefficient of polarizability related with the collective orientational effects of dipoles in external field are obtained. The Clausius-Mossotti equation for effective dielectric constant on the space-time scale's of external standing field is generalized. The effective parallel algorithm for computation of stationary dielectric constant in conditions far from equilibrium is proposed.
|February 11, 2010, at 11.00 ( LIT, r. 310 ) the seminar LIT will be held: |
M.R. Bogdanov (MSUEE): "Computer simulation of adiabatic invariants in weakly version of KAM theory"
(materials of a PhD thesis)
|January 29, 2010, at 14.00 ( LIT, r. 310 ) the seminar LIT will be held: |
O. Chuluunbaatar: "Variation-projection methods for research in small-particle quantum systems"
(materials of a Doctor’s thesis)
|January 28, 2010, at 15.00 ( LIT, r. 310 ) the seminar LIT will be held: |
S.A. Mikheev, V.P. Tsvetkov (Tver State University, Tver, Russia): "Large critical points of density distribution of rapidly rotating superdense newtonian polytropes"
In this work we have obtained an analytic expression of density distribution of rapidly rotating superdense Newtonian polytropes by polynomials based on
degrees of parameter flatness e and a polytropic index n approximating it with an accuracy of 10-3. We have built a diagram of definition of critical
points in configuration density distribution. For the case where n=1.4, we have obtained the parameter values characterizing the analytic expression of
density near the critical points. In this work there has been studied the critical points dynamics versus e parameter. This work visualizes formation of
bumping of type A2, A3. It has been proved that near the point of e=0.3503 in density distribution, a "bubble area" in the form of elliptic torus arises.
|January 22, 2010, at 11.00 ( LIT, r. 310 ) the seminar LIT will be held: |
D.Z. Muzafarov: "Numerical study of nonlinear equations in the models of thermal spike and polaron evolution"
(Materials of a PhD thesis)
|Archive of LIT Seminars (2009)