Seminar KiDM
Izvor: KiWi
Seminar se održava četvrtkom od 17 do 19 sati u predavaonici 109 na PMF-Matematičkom odjelu. Obavijest o održavanju seminara šalje se članovima math liste i članovima seminara. Ako želite putem e-pošte primati obavijest o rasporedu seminara, molim da mi se javite na adresu igaly@math.hr
Sadržaj |
Članovi
Članovi seminara
Voditelj: dr. Dragutin Svrtan
Tajnik: dr. Goran Igaly
Članovi: Tonći Crmarić, dr. Tomislav Došlić, Mathieu Dutour, dr. Svjetlan Feretić, dr. Goran Igaly, dr. Antoaneta Klobučar (Sveučilište u Osijeku), Snježana Majstorović (Sveučilište u Osijeku), Mandi Orlić, Sarah Michele Rajtmajer (University of Dubrovnik), mr. Jelena Sedlar (Sveučilište u Splitu), dr. Dragutin Svrtan, dr. Darko Veljan, dr. Damir Vukičević, mr. Milena Sošić, dr. Igor Urbiha, Tanja Vojković
Predavanja
Najavljujemo:
- Lavoslav Čaklović: Inkonzistentnost grafova preferencija (u pripremi)
Predavanja u akademskoj godini 2011/12.
- 08.12.2011. Ivica Martinjak: Taktičke dekompozicije simetričnih dizajna
- 01.12.2011. Igor Urbiha: Sternov dijatomički niz (3)
- 17.11.2011. Igor Urbiha: Sternov dijatomički niz (2)
- 10.11.2011. Igor Urbiha: Sternov dijatomički niz
- 03.11.2011. Tomislav Došlić: Prebrojavanje konjugiranih ciklusa u benzenoidnim lancima
Predavanja u akademskoj godini 2010/11.
- 26.05.2011. Jelena Sedlar: Nezavisni skupovi u lančanim kaktusima (Independent sets in chain cacti)
- 28.04.2011. Milena Sošić: Računanje konstanti u nekim potprostorima slobodne asocijativne kompleksne algebre - treći dio
- 14.04.2011. Snježana Majstorović: Totalne dominacije na m-kaktus lancima i dominacije na višestrukim linearnim heksagonalnim lancima (3.dio)
- 13.04.2011. Damir Vukičević: Dvije primjene diskretnih matematičkih modela u ekonomiji i socijalnoj evoluciji
- 07.04.2011. Milena Sošić: Računanje konstanti u nekim potprostorima slobodne asocijativne kompleksne algebre – drugi dio
- 25.03.2011. Sarah Rajtmajer: Community Structure and Hub Detection in Complex Networks (PART II: Hub Detection) sažetak
- 24.03.2011. Milena Sošić: Računanje konstanti u nekim potprostorima slobodne asocijativne kompleksne algebre
- 24.03.2011. Sarah Rajtmajer: Community Structure and Hub Detection in Complex Networks (PART I: Community Structure Detection) sažetak
- 10.02.2011. Sarah Rajtmajer: NP-Completeness of the Modularity problem on complex networks
- 27.01.2011. Snježana Majstorović: Dominacije na m-kaktus lancima (2. dio) sažetak
- 20.01.2011. Snježana Majstorović: Dominacije na m-kaktus lancima sažetak
- 16.12.2010. Milena Sošić: Formule za bazične konstante u multiparametarskim quonskim algebrama
- 25.11.2010. Tomislav Došlić: Raspodjela π-elektrona u benzenoidnim paralelogramima
- 21.10.2010. Damir Vukičević: Bridno aditivno modeliranje
Predavanja u akademskoj godini 2009/10.
- 31.05.2010. Sarah Michele Rajtmajer: Structure Analysis and Hub Detection in Complex Networks
(Joint work with Damir Vukicevic) We present a structural analysis of complex networks. More specifically, we speak about communities and hubs in the networks. We examine Estrada’s method for community structure detection and some of its properties. We additionally propose a novel method for fast detection of hubs within a system. The algorithm identifies a set of nodes in the network as most significant, aimed to be the most effective points of distribution for fast, widespread coverage throughout the system. We show that our hubs have in general greater closeness centrality and betweenness centrality than vertices with maximal degree, and have in general higher degree than vertices with greatest closeness centrality and betweenness centrality. As such, they serve as all-purpose network hubs. Several theoretical and real world networks are tested and results are analyzed. We further develop a classification of three types of hubs related to the spread of SIR-type epidemics. We define a network outhub as a node which, if infected first, causes the most extensive spread of a disease throughout the network. An inhub is a node which is most likely to become infected at some point during the spread of the disease through the system. And a network transitive hub is a node which, if vaccinated, most decreases the spread of the disease through the system. We show that on some networks, these three hubs are distinct, indicating the need for more specific identification of network hubs than the general use of vertex degree and connectivity.
- 27.05.2010. Jelena Sedlar: Globalni prisiljavajući broj benzenoidnog paralelograma
- 13.05.2010. Mathieu Dutour: The homology of PSL4(Z)
Abstract: The homology of the group SL3(Z) was determied by Soule. The notion of group homology can be defined from the action of a group acting fixed point free on a space X. For the group SL3(Z) and PSL4(Z) it is not easy to find such space, but if one make such groups act on the space of quadratic form, then one gets an action whose stabilizers are finite. We can then apply perturbation techniques and compute some homology groups. In particular we found the groups H_n(PSL4(Z),Z) for n<=5 and we computed explicitly the 5-part of those groups.
- 29.04.2010. Tomislav Došlić: Strukturalni i enumerativni aspekti maksimalnih sparivanja u nanostrukturama
- 01.04.2010. Mathieu Dutour: Space fullerenes: computer search for new Frank-Kasper structures
Abstract: A Frank-Kasper structure is a 3-periodic tiling of the Euclidean space E^3 by tetrahedra such that the vertex figure of any vertex belongs to 4 specified patterns with, respectively, 20, 24, 26, 28 faces. Those polyhedra correspond to fullerenes with isolated hexagons. Frank-Kasper structures occur in the crystallography of metallic alloys and clathrates but also in the solution of Kelvin's conjecture.
A new computer enumeration method has been devised for obtaining Frank-Kasper structures up to 20 cells in a reduced fundamental domain. The method decomposes in two parts: one combinatorial of enumeration of possibilities. Another topological of recognition of the structure by the use of Delaney symbols and the program 3dt. We compared the 84 obtained structure with the known 27 physical structures and the known special constructions by Deza-Shtogrin, Sadoc-Mossieri, Frank-Kasper-Sullivan and Shoemaker-Shoemaker.
- 25.03.2010. Damir Vukičević: Mreže i zajednice
- 18.03.2010. Mathieu Dutour: Covering maxima and Delaunay polytopes in lattices
Abstract: A family of balls in Euclidean space is called a packing if for any two balls B and B' their interior do not self-intersect. It is called a covering if every point belong to at least one ball.
We focus here on packings and coverings for which the calls are of the form x + B(0,R) with x belonging to a lattice L. If L is fixed then we adjust the value of R to a value R0 to find the best packing. Alternatively we can adjust the value of R to a value R1 to find the best covering. This allow us to define the packing density pack(L) and covering density cov(L) of L.
The geometry of the function pack on the space of lattices has been elucidated by Minkovski, Voronoi and Ash. They showed that the function pack has no local minimum, that it is a Morse function and they give a characterization of the local maximum in terms of the algebraic notions of perfection and eutaxy.
The covering function cov is much more complex. It has local minimum and local maximum and it is not a Morse function. We also characterize the local maximum of the covering density in terms of the corresponding notions of perfection and eutaxy this time for Delaunay polytope.
- 11.03.2010. Dragutin Svrtan: Kombinatorne formule za inverz polinomijalnih preslikavanja
- 17.12.2009. Sarah Michele Rajtmajer: A Note on the Estrada Algorithm for Community Structure Detection in Complex Networks
- 03.12.2009. Dragutin Svrtan: Dokaz Đokovićevih hipoteza za diedralne konfiguracije (2. dio)
- 26.11.2009. Dragutin Svrtan: Dokaz Đokovićevih hipoteza za diedralne konfiguracije
Predavanja u akademskoj godini 2008/09.
(za svako od predavanja trebalo bi staviti u koju kategoriju spada: originalni rad ili rad iz literature)
- 03.06.2009. Damir Vukičević: Koji su generalizirani Randićevi indeksi prikladne mjere grananja kemijskih molekula? sažetak
- 23.04.2009. Tanja Vojković: O degeneraciji molekulskog identifikacijskog broja MID06 sažetak (originalan rad)
- 02.04.2009. Jelena Sedlar: Generiranje i dokazivanje slutnji o binomnim invarijantama grafova
- 26.03.2009. Sarah Michele Rajtmajer: Community Structure in graphs - second part
- 19.03.2009. Dragutin Svrtan: Primjene Gröbnerovih baza na Robbinsov problem
- 05.03.2009. Igor Urbiha: Gröbnerova baza i Buchbergerov algoritam, 'rad iz literature'
- 26.02.2009. Mathieu Dutour: Practical polyhedral computation under symmetry
- 19.02.2009. Jelena Sedlar: Ograničavanje binomnih graf teorijskih invarijanti brojem bridova
- 04.12.2008. Sarah Michele Rajtmajer: Finding and Evaluating Community Structure in Networks
- 20.11.2008. Dragutin Svrtan: Teorija Sabitova i jednadžbe volumena oktaedara II
- 13.11.2008. Dragutin Svrtan: Teorija Sabitova i jednadžbe volumena oktaedara
- 06.11.2008. Tomislav Došlić: Konveksnost i logaritamska konveksnost kombinatornih nizova
Predavanja u akademskoj godini 2007/08.
(za svako od predavanja trebalo bi staviti u koju kategoriju spada: originalni rad ili rad iz literature)
- 29.05.2008. Damir Vukičević: Ekstremalne vrijednosti omjera brojeva staza dane duzine u grafovima
- 15.05.2008. Damir Vukičević: Ekstremalne vrijednosti omjera brojeva staza dane duzine u grafovima
- 13.05.2008. Sarah Michele Rajtmajer: The Anti-Kekule Number of the 3D Rectangular Grid
- 29.04.2008. Dragutin Svrtan: Računanje volumena konformnih simpleksa i Connellyeva hipoteza
- 08.04.2008. Dragutin Svrtan: Diskretne ekskurzije i simetrične funkcije II
- 01.04.2008. Dragutin Svrtan: Diskretne ekskurzije i simetrične funkcije
- 25.03.2008. Dragutin Svrtan: Diskretne ekskurzije
- 18.12.2007. Sarah Rajtmajer: Maximizing Zagreb Index
- 11.12.2007. Tomislav Došlić: Graf-teoretički indikatori stabilnosti fulerena
- 04.12.2007. Dragutin Svrtan: Stabla i operade
- 27.11.2007. Mandi Orlić: Bicentrički poligoni
- 20.11.2007. Dragutin Svrtan: Kombinatorika stabala
- 13.11.2007. Dragutin Svrtan: Konvergencija rješenja matričnih jednadžbi i Langrangeova inverzija
Gosti
Gosti Seminara u 2007/08
(ne mogu se sjetiti nikoga)
Gostovanja članova Seminara u 2007/08
Treba navesti gdje i kada ste gostovali, te koja je bila tema predavanja
- Tomislav Došlić: PMF u Sarajevu, Bosna i Hercegovina, 3.-5.V 2008.
Predavanje: Seven (lattice) paths to log-convexity
- Damir Vukičević: Comparing Zagreb indices, svibanj 2008, Ljubljana, Slovenija
Izlaganja na konferencijama u 2007/08
- Darko Veljan, Mathematical Inequalities and Applications 2008, Trogir,8.-14.VI 2008.
Predavanje: Non-Euclidean geometric inequalities in geometry, topology and physics.
- Tomislav Došlić: Mathematical Inequalities and Applications 2008, Trogir, lipanj 2008.
Predavanje: Log-convexity and how to prove it
- Darko Veljan, Četvrti hrvatski matematički kongres, Osijek, 12.-20.VI 2008.
Predavanje: Geometry of pentagons and volumes of fullerenes.
- Darko Veljan, Fifth European Congress of Mathematics, Amsterdam, Nizozemska, 14.-18.VII 2008.
Saopćenje: Geometry of pentagons and volumes of fullerenes.
- Tomislav Došlić: 13th Scientic-Professional Colloquium of CSGG, Poreč, rujan 2008.
Predavanje: Golden Section in paintings: is the cat there?
- Darko Veljan: Hrvatski prirodoslovci 17, Odjel za prirodosl. i matematiku Matice hrvatske, Varaždin, 16-17..X 2008.
Predavanje: Matematički fizičar, akademik Zlatko Janković.
- Damir Vukičević: On the Edge Degrees of Trees, Četvrti hrvatski matematički kongres, Osijek,
- Damir Vukičević: On the Ratios of the Numbers of Paths and Walks in Graphs, Math/Chem/Comp, Verabnia-Intra, Italy
