1. The Sierpiński product of graphsJurij Kovič, Tomaž Pisanski, Sara Sabrina Zemljič, Arjana Žitnik, 2023, original scientific article Abstract: In this paper we introduce a product-like operation that generalizes the construction of the generalized Sierpiński graphs. Let ▫$G, \, H$▫ be graphs and let ▫$f: V(G) \to V(H)$▫ be a function. Then the Sierpiński product of graphs ▫$G$▫ and ▫$H$▫ with respect to ▫$f$▫, denoted by ▫$G\otimes_f H$▫, is defined as the graph on the vertex set ▫$V(G) \times V(H)$▫, consisting of ▫$|V(G)|$▫ copies of ▫$H$▫; for every edge ▫$\{g, g'\}$▫ of ▫$G▫$ there is an edge between copies ▫$gH$▫ and ▫$g'H$▫ of form ▫$\{(g, f(g'), (g', f(g))\}$▫. Some basic properties of the Sierpiński product are presented. In particular, we show that the graph ▫$G\otimes_f H$▫ is connected if and only if both graphs ▫$G$▫ and ▫$H$▫ are connected and we present some conditions that ▫$G, \, H$▫ must fulfill for ▫$G\otimes_f H$▫ to be planar. As for symmetry properties, we show which automorphisms of ▫$G$▫ and ▫$H$▫ extend to automorphisms of ▫$G\otimes_f H$▫. In several cases we can also describe the whole automorphism group of the graph ▫$G\otimes_f H$▫. Finally, we show how to extend the Sierpiński product to multiple factors in a natural way. By applying this operation ▫$n$▫ times to the same graph we obtain an alternative approach to the well-known ▫$n$▫-th generalized Sierpiński graph. Keywords: Sierpiński graphs, graph products, connectivity, planarity, symmetry Published in RUP: 06.11.2023; Views: 314; Downloads: 3 Full text (526,44 KB) |
2. Izseljevanje Slovencev v Avstralijo po 2. svetovni vojni s poudarkom na vzrokih za izseljevanje in integraciji : magistrsko deloVesna Taljat, 2023, master's thesis Keywords: izseljevanje, Avstralija, imigracijska politika, integracija, avstralski Slovenci, etnična identiteta, zgodovina, magistrske naloge Published in RUP: 05.10.2023; Views: 641; Downloads: 4 Full text (2,38 MB) |
3. Upravna struktura in turističen razvoj Škocjanskih jam med letoma 1945 in 1997 : magistrsko deloUrška Ivančič Petelin, 2022, master's thesis Keywords: Škocjanske jame, upravljanje, upravljavec, turizem, 1945-1997, Kraške jame Slovenije, Turistični zavod Škocjanske jame, ObLO Divača, zavod Postojnska jama, Kras Sežana, TOZD Gostinstvo Sežana, HTG Sežana, TOP Portorož, UNESCO in Javni zavod Park Škocjanske jame, Slovenija, zgodovina, magistrske naloge Published in RUP: 08.07.2022; Views: 1447; Downloads: 28 Full text (1,21 MB) |
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7. Combinatorial configurations, quasiline arrangements, and systems of curves on surfacesJürgen Bokowski, Jurij Kovič, Tomaž Pisanski, Arjana Žitnik, 2018, original scientific article Keywords: pseudoline arrangement, quasiline arrangement, projective plane, incidence structure, combinatorial configuration, topological configuration, geometric configuration, sweep, wiring diagram, allowable sequence of permutations, maps on surfaces Published in RUP: 03.01.2022; Views: 753; Downloads: 17 Full text (3,66 MB) |
8. Classification of convex polyhedra by their rotational orbit Euler characteristicJurij Kovič, 2017, original scientific article Abstract: Let ▫$\mathcal P$▫ be a polyhedron whose boundary consists of flat polygonal faces on some compact surface ▫$S(\mathcal P)$▫ (not necessarily homeomorphic to the sphere ▫$S^{2}$)▫. Let ▫$vo_{R}(\mathcal P), eo_{R}(\mathcal P)$▫, ▫$ fo_{R}(\mathcal P)$▫ be the numbers of rotational orbits of vertices, edges and faces, respectively, determined by the group ▫$G = G_{R}(P)$▫ of all the rotations of the Euclidean space ▫$E^{3}$▫ preserving ▫$\mathcal P$▫. We define the ''rotational orbit Euler characteristic'' of ▫$\mathcal P$▫ as the number ▫$Eo_{R}(\mathcal P) = vo_{R}(\mathcal P) - eo_{R}(\mathcal P) + fo_{R}(\mathcal P)$▫. Using the Burnside lemma we obtain the lower and the upper bound for ▫$Eo_{R}(\mathcal P)$▫ in terms of the genus of the surface ▫$S(P)$▫. We prove that ▫$Eo_{R} \in \lbrace 2,1,0,-1\rbrace $▫ for any convex polyhedron ▫$\mathcal P$▫. In the non-convex case ▫$Eo_{R}$▫ may be arbitrarily large or small. Keywords: polyhedron, rotational orbit, Euler characteristic Published in RUP: 03.01.2022; Views: 796; Downloads: 18 Full text (272,96 KB) |
9. Point-ellipse configurations and related topicsGábor Gévay, Nino Bašić, Jurij Kovič, Tomaž Pisanski, 2021, original scientific article Keywords: point-line configuration, conic section, point-ellipse configuration, point-conic configuration, Levi graph, Carnot's theorem Published in RUP: 18.10.2021; Views: 1253; Downloads: 21 Link to full text |
10. Športne prireditve kot del turistične ponudbe : primer Evropskega univerzitetnega prvenstva v odbojki na mivkiMiroslav Jurij Butina, 2007, undergraduate thesis Keywords: športni turizem, šport, rekreacija, prireditve, management prireditev, organizacija, turistični proizvod, strategija razvoja, odbojka, tekmovanja, analize, diplomske naloge Published in RUP: 14.05.2021; Views: 1059; Downloads: 34 Full text (1,23 MB) |