Seminar za računarstvo i primenjenu matematiku, 6. oktobar 2014.

Zajednički sastanak Seminara za računarstvo i primenjenu matematiku biće održan u ponedeljak, 6. oktobra 2014. u sali 301f sa početkom u 14:15.

Predavač: Prof. Zoran Obradović, Temple University, Philadelphia, USA

Naslov predavanja: NEURAL GAUSSIAN CONDITIONAL RANDOM FIELDS AND HOSPITAL PRICING ESTIMATION BY STRUCTURED REGRESSION ON A TEMPORAL GRAPH

Sadržaj: First, we will show how to improve the representational power of Gaussian Conditional Random Field (GCRF) model for structured regression by (1) introducing an adaptive feature function that can learn nonlinear relationships between inputs and outputs and (2) allowing the weights of feature functions to be dependent on inputs. Experimental evaluation on the remote sensing problem of aerosol estimation from satellite measurements and on the problem of document retrieval showed that the proposed model is more accurate than the benchmark alternatives. Then, we will describe how we used GCRF to estimate unreported hospital charges by utilizing structured regression on a temporal graph of more than 4,000 hospitals observed over 8 years constructed from the US National Inpatient Sample database. The estimates of cost-to-charge ratio obtained using convex optimization of the GCRF parameters on the constructed graph were much better than those relying on group average based cost-to-charge estimates. In addition, cost-to-charge ratio estimates by our GCRF model outperformed regression by nonlinear artificial neural networks.

The first result is obtained in joint research with V. Radosavljevic and S. Vucetic and will be published at the Proc. European Conf. on Machine Learning and Principles and Practice of Knowledge Discovery in Databases, Nancy, France, September, 2014. The second result is obtained jointly with A. Polychronopoulou and will be published at the Proc. 2014 IEEE Int'l Conf, on Bioinformatics and Biomedicine, Belfast, UK, Nov. 2014.

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Seminar za geometiju, obrazovanje i vizuelizaciju sa primenama, 3. oktobar 2014.

Naredni sastanak seminara biće održan u četvrtak, 3. oktobra 2014. u sali 301f Matematičkog instituta SANU sa početkom u 17:15.

Predavači: Mirjana Đorić, Branko Dragović i Zoran Rakić

Naslov predavanja: Matematika danas, sutra.

Sadržaj: Profesori će prikazati neke od rezultata i utiske sa konferencija na kojima su prisustvovali u ovoj godini.

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Odeljenje za matematiku, 3. oktobar 2014.

Zajednički sastanak Odeljenja za matematiku i Seminara za istoriju i filozofiju matematike i mehanike biće održan u petak, 3. oktobra 2014. u sali 301f sa početkom u 14 časova.

Predavač: dr Menso Folkerts, Bayerische Akademie, Munich, Germany

Naslov predavanja:

PRAKTIČNA RAČUNICA U SREDNjEM VEKU I RENESANSI
PRACTICAL ARITHMETIC IN THE MIDDLE AGES AND RENAISSANCE

Sadržaj: Situacija u ranom srednjem veku 500-1100. Prevodi na latinski u 12 veku. Uloga univerziteta. Matematika izvan univerziteta, tzv. Abacistička tradicija. Doprinos Abacističke tradicije algebri.

(The early Middle Ages (ca. 500 - 1100 AD). The translation into Latin in the 13th century. The Universities. Mathematics outside universities: the abbaco tradition. The contribution of abbaco tradition to algebra).

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Seminar iz astronomije i astrofizike, 30. septembar 2014.

Naredni sastanak Seminara biće održan u utorak, 30. septembra 2014. sa početkom u 18h u sali 809 Matematičkog fakulteta, V sprat.

Predavač: dr Sonia Giovanna Temporin, Institute for Astro- and Particle Physics, University of Innsbruck

Naslov predavanja: Small galaxy groups and their role in galaxy evolution

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CGTA seminar, 30. septembar 2014.

Naredni sastanak CGTA seminara biće održan u utorak, 30. septembra 2014. od 14-16h u sali 844 Matematičkog fakulteta, 5. sprat.

Predavač: Jovana Đuretić, Matematički fakultet, Beograd

Naslov predavanja: O kobordizmima i Štifel-Vitnijevim brojevima

Sadržaj: Poznati rezultat Toma (Rene Thom) kaže da su dve mnogostrukosti kobordantne ako i samo ako imaju jednake Štifel-Vitnijeve brojeve.

Biće skiciran dokaz ovog rezultata baziran na idejama Buonkristijana i Hakona (Buoncristiano, Hacon).

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Seminar Geometrija, obrazovanje i vizuelizacija sa primenama, 25. septembar 2014.

Naredni sastanak Seminara biće održan u četvrtak, 25. septembra 2014. sa početkom u 17:15 časova u sali 301f MI SANU.

Predavač: Prof. Salvatore Capozziello, Universita di Napoli, Italy

Naslov predavanja: Hamiltonian Dynamics and Symmetries in Extended Gravity Cosmology

Sadržaj:

We discuss the Hamiltonian dynamics for cosmologies coming from Extended Theories of Gravity. In particular, minisuperspace models are taken into account searching for Noether symmetries. The existence of conserved quantities gives selection rules to recover classical behaviors in cosmic evolution according to the so called Hartle criterion, that allows to select correlated regions in the configuration space of dynamical variables.

We show that such a statement works for general classes of Extended Theories of Gravity and is conformally preserved. Furthermore, the presence of Noether symmetries allows a straightforward classification of singularities that represent the points where the symmetry is broken. Examples for nonminimally coupled and models are discussed.

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Matematički fakultet u Noći istraživača 2014, 26. septembar 2014.

Noć istraživača je manifestacija koja se organizuje širom Evrope sa ciljem da zainteresovanima svih uzrasta na dostupan i interesantan način približi svet nauke i istraživanja.

Pored cilja da afirmiše nauku i istraživače, ova manifestacija teži da podstakne mlade na istraživačko-naučnu karijeru kroz niz besplatnih programa koji će biti održani u petak 26. septembra od 17 do 23 sata.

Ove godine Noć istraživača će biti istovremeno održana u devet gradova Srbije: u Beogradu, Novom Sadu, Nišu, Kragujevcu, Subotici, Zrenjaninu, Pančevu, Jagodini i Ćupriji.


Matematički fakultet učestvuje u aktivnostima u Noći istraživača u Beogradu na Trgu Republike, u bivšoj robnoj kući Nama, u Knez Mihailovoj i u Ušće šoping centru.

Više detalja može se naći na strani.

Noć istraživača 2014 se organizuje u okviru projekta FLIRT (Fall in Love with Science Tonight), iz programa Horizon 2020.

Nosilac projekta je Centar za promociju nauke i umetnosti, a Matematički fakultet je jedan od partnera na projektu.

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Odeljenje za matematiku, 26. septembar 2014.

Sastanak Odeljenja za matematiku biće održan u petak, 26. septembra 2014. u sali 301f sa početkom u 14 časova.

Predavač: Ulrich Koschorke, University of Siegen

Naslov predavanja: TOPOLOGICAL FIXED POINT AND COINCIDENCE THEORY

Sadržaj: In topological fixed point theory we are mainly interested in the following question. Can a given selfmap $f$ of a manifold $M$ be deformed continuously until it has no fixed points? And we try to measure to what extent $f$ fails to be 'homotopically fixed point free' in  this sense. The classical Lefschetz number yields a necessary condition. But a much better measure is the Nielsen number of $f$. It vanishes precisely if $f$ is homotopic to a fixed point free map EXCEPT when $M$ is a surface with strictly negative Euler characteristic (in which case this statement can be dramatically wrong).

In coincidence theory we do not just compare a selfmap $f$ with the identity map but we study the coincidence set $C$ of an arbitrary pair $f,g$ of maps from the domain $M$ to a possibly different target manifold $N$ (i. e. $C$ is the set of points $x$ in $M$ where $f(x)=g(x)$). Can the maps $f,g$  be deformed away from one another? In other words: can $C$ be made empty by suitable homotopies?

Since the dimensions $m$ and $n$ of the domain and the target need not agree, generically the coincidence set $C$ will be an ($m$-$n$)-dimensional manifold (and not just consist of isolated points as in the fixed point setting). Thus the geometric methods of differential topology come into play, and deep notions such as bordism, Kervaire invariants, Hopf invariants etc. enter the picture. In particular, Nielsen numbers get a new, deeper meaning and answer some, but not all central questions (and may allow us to measure what can go wrong).

REFERENCE: U. Koschorke,  Minimum numbers and Wecken theorems in topological coincidence theory. I, J. Fixed Point Theory Appl. 10, 1 (2011), 3-36.

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CGTA seminar, 23. septembar 2014.

Naredni sastanak CGTA seminara biće održan u utorak, 23. septembra 2014. od 14-16 časova u sali 844 Matematičkog fakulteta, 5. sprat.

Predavač: Rade Živaljević

Naslov predavanja: Pregled osnovnih rezltata teorije kobordizama

Sadržaj: U okviru pripreme za predavanje Ulriha Koschorke-a, planirano za 26. septembar 2014, podsetićemo se najvažnijih delova teorije kobordizama (konstrukcija Pontrijagina-Toma, normalni bordizmi).

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Organizovane posete zgradi Rektorata Univerziteta u Beogradu

U okviru manifestacije "Dani evropske baštine" Rektorat Univerziteta u Beogradu otvoriće vrata Kapetan Mišinog zdanja za zainteresovane posetioce (u nedelju 21. septembra, kao i 28. septembra u terminima 13, 14, 15, 16 i 17 časova).

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