Mathematical Colloquim
PROGRAM
ODELJENJE ZA MATEMATIKU MATEMATICKOG INSTITUTA SANU |
OPSTI MATEMATICKI SEMINAR NA MATEMATICKOM FAKULTETU U BEOGRADU |
-- PROGRAM ZA OKTOBAR 2005 --
Petak, 07. oktobar 2005. u 14h, sala 2 MI SANU BG:
Miroslav Ciric, University of Nis, Faculty of Sciences and Mathematics
FUZZY RELATIONS AND THEIR APPLICATIONS
Abstract: The concept of a fuzzy relation naturally arose from that of fuzzy
set in Zadeh's
very first paper on fuzzy sets, and it was further developed in his 1971
paper, where the
notions of a fuzzy equivalence relation and fuzzy ordering were introduced.
After that, a
number of papers dealing with various aspects related with these relations
have appeared,
and today, the theory of fuzzy binary relations is probably one of the most
important and
influential branches of fuzzy set theory. By allowing intermediate degrees
of relationship,
fuzzy relations provide much more freedom to express the subtle nuances of
human
preferences so they found natural applications in modelling various concepts
inherent to
so-called ^Soft' sciences like psychology, sociology, linguistics, etc.
Here we give a survey of the most interesting results concerning fuzzy
equivalence relations,
fuzzy quasi-orders, fuzzy tolerance (preference) relations, and their
applications in fuzzy
cluster analysis, fuzzy control, approximate reasoning etc.
Petak, 14. oktobar 2005. u 14h, sala 2 MI SANU:
Katica (Stevanovic) Hedrih, Masinski fakultet, Nis
SOLUTION OF THE TWO COUPLED PARTIAL FRACTIONAL ORDER DIFFERENTIAL EQUATIONS
Abstract: The solution of the two coupled partial fractional order
differential equations of transversal vibrations of a creeping connected
double plate homogeneous system have been derived. The analytical solution
of system coupled partial fractional differential equations of corresponding
dynamical free and forced processes are obtained by using method of
Bernoulli's particular integral and Laplace's transform method. By using
inverse Laplace's transform it is obtained time series function as a
particular components of the solution. By using these components
visualizations an analysis of the solution components is done.
Keywords: Fractional order derivative, partial fractional-differential
equations, visualization, double plate homogeneous system.
Petak, 21. oktobar 2005. u 14h, sala 2 MI SANU:
Henning Haahr Andersen, Department of Mathematics, Aarhus University,
Denmark
TWISTING FUNCTORS ON HIGHEST WEIGHT CATEGORIES
Abstract: Some 35 years ago J. Bernstein, I. M. Gelfand, and S. I. Gelfand
introduced a category of highest weight modules for a semisimple complex Lie
algebra. In this talk I shall discuss some recent progress in understanding
the finer structure of this category via certain twisting functors. These
are operations which to standard objects in the category associate modules
with the same composition factors but with new and interesting submodule
structure. They turn out to be equivalences on the level of derived
categories. This fact in turn can be used for instance to give information
about their values on simple modules. Our approach works equally well for
quantum groups.
Petak, 28. oktobar 2005. u 12h, bibloteka, MI SANU:
Miodrag M. Spalevic, Prirodno-matematicki fakultet, Kragujevac
GRANICE GRESAKA GAUSS-TURAN-ovih KVADRATURNIH FORMULA ZA ANALITICKE FUNKCIJE
Sadrzaj: Cuvene Gaussove
kvadraturne formule za aproksimiranje razvijane su u vise pravaca. Jedan od
njih je teorija kvadratura sa visestrukim cvorovima, tj. Gauss-Turan-ovih
kvadraturnih formula
???
Nas cilj je analiza ostataka u slucaju kada je f analiticka funkcija u
nekoj oblasti kompleksne ravni koja u svojoj unutrasnjosti sadrzi interval .
U okviru ovog predavanja bice izlozen pregled nedavno dobijenih rezultata
(zajedno sa prof. G. V. Milovanovicem).
Petak, 28. oktobar 2005. u 14h, sala 718, MF BG:
Predavanja ce se odrzavati na Matematickom Institutu (sala 2),
petkom sa pocetkom u 14 casova. Odeljenje za matematiku je opsti seminar
sa najduzom tradicijom u Institutu.
Svakog meseca, jedno predavanje ce biti odrzano na Matematickom Fakultetu
u terminu koji ce biti posebno odredjen.
Molimo sve zainteresovane ucesnike u radu naucnih sastanaka da posebno
obrate paznju na vreme odrzavanja svakog sastanka. Na Matematickom
fakultetu su moguce izmene termina.
Obavestenje o programu naucnih sastanaka ce biti objavljeno na oglasnim
tablama MI (Beograd), MF (Beograd), PMF (Novi Sad), PMF (Nis) i PMF (Kragujevac).
Odeljenje za matematiku
Matematickog instituta SANU
Stevan Pilipovic
Opsti matematicki seminar na Matematickom
fakultetu u Beogradu,
Sinisa Vrecica
Ako zelite da se obavestenja o Vasim naucnim
skupovima pojave u
Newsletter of EMS (European Mathematical Society)
i na Internetu na lokaciji EMS, onda se obratite na
emsvesti@mi.sanu.ac.yu
gde cete dobiti format obavestenja.
Mathieu Dutour Sikiric, Ecole Normale Superieure, Paris, France, (visiting
Institut "Rudjer Boskovic" Zagreb)
FACE REGULAR MAPS
Abstract: Call two-faced map and, specifically, (p,q)-map a 3-valent
3-connected map (on sphere or torus) with only p- and q-gonal faces (at
least one each), for given integers 3 (
p
Here we address the characterization of all weakly face-regular (p,q)-maps
on sphere or torus.
Examples of obtained results:
1. Any (3,q)-map is 3R0 and have 4 ( q ( 12. It is strongly face-regular for
q=4,5 (Prism3 and Barrel3 only) and q=11,12 (only tori, unique for
q=12).
2. All such weakly face-regular maps are infitities of polyhedra and tori
for each 7 ( q ( 10 and (characterized) infinity of (3,6)-polyhedra.
3. (5,q)-polyhedra 5Rj exist, besides classified case j=2, only for j=3, 6 (
q ( 10.
4. If a (p,q)-polyhedron is qRj, then j( 5. The number of such polyhedra is
infinite if and only if q ( 12,10,8,7,7 for j=0,1,2,3,4,5, respectively
(except some undecided cases for j=0,3,5). (5,q)-torus 5Rj was found exactly
for all cases, when the number of (5,q)-polyhedra qRj was proven to be
infinite.
5. In many cases full classification was reached.
We used large computations, variations of Euler formula, analysis of coronae
of faces, the decomposition of (p,q)-maps into elementary (p,3)-polycycles
and many ad hoc arguments.
Rukovodioci Odeljenja za matematiku Matematickog instituta SANU i
Opsteg matematickog seminara na Matematickom fakultetu u Beogradu,
Stevan Pilipovic i Sinisa Vrecica predlazu zajednicki program rada
naucnih sastanaka.