
Veuillez noter que l'horaire peut Ãªtre modifiÃ© sans prÃ©avis, surtout s'il s'agit de modifications Ã l'intÃ©rieur d'une session.
Applications of Generating Functions (CM5)  
Responsable et prÃ©sident: Alois Panholzer (Technische UniversitÃ¤t Wien)  
Starting with Leonard Euler's computation of the number of triangulations of a convex $n$gon generating functions are an indispensable tool in combinatorial enumeration. Generating functions allow to apply algebraic and analytic techniques and thus might be considered as a bridge between both ``worlds''. Often inspired by concrete problems from the analysis of algorithms and data structures, powerful analytic combinatorics methods have been developed to describe the asymptotic behaviour of quantities in random structures. In this minisymposium several such recent results will be presented, where generating functions techniques play an essential r\^{o}le.  
lundi 10 juin  
15:15  15:40  Bernhard Gittenberger (Technische UniversitÃ¤t Wien), Associative and commutative tree representations for Boolean functions, Science SN2101 
15:45  16:10  Helmut Prodinger (Stellenbosch University), Generating functions in the analysis of $m$versions of approximate counting, binary search trees and other structures, Science SN2101 
16:15  16:40  Alfredo Viola (Universidad de la RepÃºblica), Counting reducible, powerful, and relatively irreducible multivariate polynomials over finite fields, Science SN2101 
16:45  17:10  Mark Daniel Ward (Purdue University), Recent Directions in Tries, Pattern Matching, Suffix Trees, and Subword Complexity, Science SN2101 
17:15  17:40  MarieLouise Bruner (Vienna University of Technology, Austria), Parking in trees, Science SN2101 
Applied Combinatorics and the Natural Sciences I (CM16)  
PrÃ©sident: Chris Soteros (University of Saskatchewan) Org: Marni Mishna (Simon Fraser University), Chris Soteros (University of Saskatchewan) et Karen Yeats (Simon Fraser University)  
The natural sciences provide a rich source of inspiration for discrete mathematics. The proposed minisymposia (2 sessions with 45 speakers each) bring together researchers with a common interest in combinatorial modelling of natural phenomena in chemistry, physics and biology. Areas of application include: phase transitions, models of DNA/RNA, and quantum field theory. Combinatorial approaches include: integral and functional equation methods, kernel method, Monte Carlo and random generation schemes. The session speakers reflect a mixture of applied combinatorics expertise: some focussed more on the analytical and computational tools while others focussed more on the applications. This crossfertilization at the interface between discrete mathematics and the natural sciences will inspire improvements both in the models and in the combinatorial analysis.  
mercredi 12 juin  
10:10  10:35  Stuart Whittington (University of Toronto, Canada), Partially directed walks and polymer adsorption on striped surfaces, Science SN2105 
10:40  11:05  Marni Mishna (Simon Fraser University, Canada), A combinatorial approach to lattice path asymptotics, Science SN2105 
11:10  11:35  Aleks Owczarek (University of Melbourne, Australia), Exact solution of two friendly walks above a sticky wall with single and double interactions, Science SN2105 
11:40  12:05  Iain Crump (Simon Fraser University, Canada), Forbidden minors and Feynman graphs, Science SN2105 
12:10  12:35  Michael Szafron (University of Saskatchewan, Canada), Using selfavoiding polygons to study DNAEnzyme Interactions, Science SN2105 
Applied Combinatorics and the Natural Sciences II (CM23)  
PrÃ©sident: Marni Mishna (Simon Fraser University) Org: Marni Mishna (Simon Fraser University), Chris Soteros (University of Saskatchewan) et Karen Yeats (Simon Fraser University)  
The natural sciences provide a rich source of inspiration for discrete mathematics. The proposed minisymposia (2 sessions with 45 speakers each) bring together researchers with a common interest in combinatorial modelling of natural phenomena in chemistry, physics and biology. Areas of application include: phase transitions, models of DNA/RNA, and quantum field theory. Combinatorial approaches include: integral and functional equation methods, kernel method, Monte Carlo and random generation schemes. The session speakers reflect a mixture of applied combinatorics expertise: some focussed more on the analytical and computational tools while others focussed more on the applications. This crossfertilization at the interface between discrete mathematics and the natural sciences will inspire improvements both in the models and in the combinatorial analysis.  
jeudi 13 juin  
10:10  10:35  E. J. Janse van Rensburg (York University, Canada), Some results on inhomogeneous percolation, Science SN2101 
10:40  11:05  Sophie Burrill (Simon Fraser University, Canada), Using generating trees to construct Skolem sequences, Science SN2101 
11:10  11:35  Chris Soteros (University of Saskatchewan, Canada), Combinatorics of the entanglement complexity of stretched polygons in a lattice tube, Science SN2101 
11:40  12:05  Tom Boothby (Simon Fraser University), Topological Metrics on Permutations, Science SN2101 
12:10  12:35  Karen Yeats (Simon Fraser University, Canada), Using combinatorics to understand DysonSchwinger equations, Science SN2101 
Chromatic Graph Theory (CM6)  
Responsable et prÃ©sident: Joan P. Hutchinson (Macalester College, emerita)  
Coloring graphs has interested practicioners since the beginning of graph theory. Over time a wide variety of approaches has been developed, turning the field into one of continuing interest and connection with other branches of graph theory and its applications. In this minisymposium we sample a range of topics: edgecoloring and its connections with Hamiltonicity; listcoloring and its uses with graphs on surfaces, planar and nonplanar; and algorithms and complexity of injective and frugal colorings and related homomorphisms.  
lundi 10 juin  
15:15  15:40  Stan Wagon (Macalester College), Computational Hamiltonianism, Science SN2098 
15:45  16:10  Gary MacGillivray (University of Victoria), Locally injective homomorphisms, Science SN2098 
16:15  16:40  Luke Postle (Emory University), Linear Isoperimetric Bounds in Graph Coloring, Science SN2098 
16:45  17:10  Joan Hutchinson (Macalester College), A variation on Heawoodlistcoloring for graphs on surfaces, Science SN2098 
Cycle Decompositions of Graphs I (CM12)  
PrÃ©sident: Mateja Sajna (University of Ottawa) Org: Andrea Burgess (Ryerson University) et Mateja Sajna (University of Ottawa)  
In the last 15 years, enormous progress has been made in the area of cycle decompositions of graphs. A breakthrough was made by Alspach, Jordon and \v{S}ajna, who determined necessary and sufficient conditions for the existence of an $m$cycle decomposition of the complete graph $K_n$. In 2011, this result was extended to complete multigraphs by Bryant, Horsley, Maenhaut, and Smith. Perhaps even more impressive are the 2012 complete solution to the longoutstanding Alspach's conjecture on decomposing complete graphs into cycles of various lengths by Bryant, Horsley, and Pettersson, and the first solution to the Oberwolfach Problem for an infinite set of orders by Bryant and Scharaschkin. Many other results on cycle decompositions of various graphs and with various prescribed properties have been proved during this time. In this 2part minisymposium, we would like to gather some of the researchers who have contributed most to this flourishing research area.  
mardi 11 juin  
15:15  15:40  Darryn Bryant (University of Queensland), Repacking in cycle decompositions., Science SN2098 
15:45  16:10  Daniel Horsley (Monash University), Decomposing complete bipartite graphs into short cycles and related results, Science SN2098 
16:15  16:40  Barbara Maenhaut (University of Queensland), Cycle decompositions of complete multigraphs, Science SN2098 
16:45  17:10  Peter Danziger (Ryerson University), Bipartite 2factorisations of complete multipartite graphs, Science SN2098 
17:15  17:40  Andrea Burgess (Ryerson University), Orthogonally resolvable cycle decompositions, Science SN2098 
Cycle Decompositions of Graphs II (CM17)  
PrÃ©sident: Andrea Burgess (Ryerson University) Org: Andrea Burgess (Ryerson University) et Mateja Sajna (University of Ottawa)  
In the last 15 years, enormous progress has been made in the area of cycle decompositions of graphs. A breakthrough was made by Alspach, Jordon and \v{S}ajna, who determined necessary and sufficient conditions for the existence of an $m$cycle decomposition of the complete graph $K_n$. In 2011, this result was extended to complete multigraphs by Bryant, Horsley, Maenhaut, and Smith. Perhaps even more impressive are the 2012 complete solution to the longoutstanding Alspach's conjecture on decomposing complete graphs into cycles of various lengths by Bryant, Horsley, and Pettersson, and the first solution to the Oberwolfach Problem for an infinite set of orders by Bryant and Scharaschkin. Many other results on cycle decompositions of various graphs and with various prescribed properties have been proved during this time. In this 2part minisymposium, we would like to gather some of the researchers who have contributed most to this flourishing research area.  
mercredi 12 juin  
10:10  10:35  Marco Buratti (UniversitÃ degli Studi di Perugia), Cycle decompositions and their automorphism groups, Science SN2098 
10:40  11:05  Danny Dyer (Memorial University), Graceful Labellings of Triangular Cacti, Science SN2098 
11:10  11:35  Heather Jordon (American Mathematical Society), Cycle Decompositions of Complete Graphs and Circulants, Science SN2098 
11:40  12:05  Sibel Ozkan (Gebze Institute of Technology), On the HamiltonWaterloo Problem with uniform cycle sizes, Science SN2098 
12:10  12:35  Mateja Sajna (University of Ottawa), On the directed Oberwolfach Problem with equal cycle length, Science SN2098 
Decidability in Automatic and Related Sequences (CM8)  
Responsable et prÃ©sident: Jeffrey Shallit (University of Waterloo)  
A sequence $(a(n))$ over a finite alphabet is said to be $k$automatic if there is a deterministic finite automaton that, on input $n$ expressed in base $k \geq 2$, reaches a state with output $a(n)$; a typical example is the classical ThueMorse sequence. The recent realization that many questions about these sequences can be phrased in the logical theory $(\mathbb{N}, +, <, V_k)$, where $V_k(n)$ is the highest power of $k$ dividing $n$, leads to a decision procedure for answering these questions. In this minisymposium we will describe this decision procedure and look at some of its many ramifications. Using the decision procedure, we can reprove many results in the literature and find new ones. Although the worstcase running time of the decision procedure is very bad, an implementation often succeeds in mechanically proving the assertions in question. We also address the limitations of the method.  
mardi 11 juin  
10:10  10:35  Jeffrey Shallit (University of Waterloo), Decidability in Automatic Sequences, Science SN2101 
10:40  11:05  Daniel Goc (University of Waterloo), Automatic TheoremProving in Automatic Sequences, Science SN2101 
11:10  11:35  Narad Rampersad (University of Winnipeg), Extremal words in the shift orbit closure of a morphic sequence, Science SN2101 
11:40  12:05  James Currie (University of Winnipeg), Abelian powers and patterns in words: problems and perspectives, Science SN2101 
12:10  12:35  Luke Schaeffer (University of Waterloo), Abelian powers in automatic sequences are not always automatic, Science SN2101 
Discrete Math Coast to Coast: Newfoundland and the West (CM24)  
PrÃ©sident: Kseniya Garaschuk (University of Victoria) Org: Gary MacGillivray (University of Victoria)  
This twopart minisymposium features a speaker from each province, where "from" means was born there, or educated there, or grew up there. One of the goals is for the talks to reflect the richness and diversity of discrete mathematics across Canada. The speakers in this part are "from" Newfoundland, BC, Alberta, Saskatchewan, and Manitoba.  
jeudi 13 juin  
10:10  10:35  Kathleen Barnetson (Memorial University of Newfoundland), Searching for Class Uniformly Resolvable Partial Coverings, Arts A1046 
10:40  11:05  Kseniya Garaschuk (University of Victoria), Fractional decompositions of dense graphs, Arts A1046 
11:10  11:35  Bill Sands (University of Calgary), Covering with intervals in distributive lattices, Arts A1046 
11:40  12:05  Karen Meagher (University of Regina), Minimum number of distinct eigenvalues of a graph, Arts A1046 
12:10  12:35  Shonda Gosselin (University of Winnipeg), Algebraic hypergraph decompositions, Arts A1046 
Discrete Math Coast to Coast: The Maritimes and the Middle (CM27)  
PrÃ©sident: Chris Duffy (University of Victoria) Org: Gary MacGillivray (University of Victoria)  
This twopart minisymposium features a speaker from each province, where "from" means was born there, or educated there, or grew up there. One of the goals is for the talks to reflect the richness and diversity of discrete mathematics across Canada. The speakers in this part are "from" New Brunswich, Nova Scotia, PEI, Quebec and Ontario.  
jeudi 13 juin  
15:15  15:40  Nancy Clarke (Acadia University), Oriented Injective Colouring, Arts A1046 
15:45  16:10  Shannon Fitzpatrick (University of Prince Edward Island), Grundy Number and the Strong Product, Arts A1046 
16:15  16:40  Ben Seamone (Universite de Montreal), Some results on strong edge colourings, Arts A1046 
16:45  17:10  MargaretEllen Messinger (Mount Allison University), The Cop Number and Tree Decompositions, Arts A1046 
17:15  17:40  Chris Duffy (University of Victoria), Game Show Scheduling and Orderings of Elements of a Product, Arts A1046 
Domination in Graphs (CM13)  
Responsable et prÃ©sident: Gary MacGillivray (University of Victoria)  
Domination is one of the most studied topics in graph theory. The goal of this minisymposuim is to string together five talks on recent progress in different aspects of this broad area.  
mardi 11 juin  
15:15  15:40  Stephen Finbow (St. Francis Xavier), Equality in the Domination Chain in Planar Triangulisations, Science SN2101 
15:45  16:10  Ortrud Oellermann (University of Winnipeg), Domination and Digital Convexity Parameters, Science SN2101 
16:15  16:40  Rick Brewster (Thompson Rivers University), Broadcast domination and its dual multipackings, Science SN2101 
16:45  17:10  Michelle Edwards (University of Victoria), Independent Domination Bicritical Graphs, Science SN2101 
17:15  17:40  Ruth Haas (Smith College), The kdominating graph, Science SN2101 
Eric Mendelsohn: Colleagues and Descendants I (CM1)  
PrÃ©sident: Brett Stevens (Carleton University) Org: Peter Danziger (Ryerson University) et Brett Stevens (Carleton University)  
These minisymposia celebrate the influence and work of Eric Mendelsohn through his collaborators, students, and other colleagues. At age 1, Eric Mendelsohn was a registered participant at the inaugural 1945 Montreal meeting of the Canadian Mathematics Society. His activities and influence in discrete mathematics continue to this day. He was hired at the Department of Mathematics at the University of Toronto in 1970, where he has been full professor since 1982. He retired from the University in 2010, and is now professor emeritus. He is currently an adjunct professor with the department of Mathematics at Ryerson University, whose support we gratefully acknowledge. Eric has 94 publications, 55 coauthors, 13 official "descendants". He has been an important force in combinatorics and discrete mathematics over many years, his energy and vision have provided many important directions and insights.  
lundi 10 juin  
10:10  10:35  Jason Brown (Dalhousie University), Colourful problems in combinatorics, Arts A1046 
10:40  11:05  Nevena Francetic (Carleton University), Relation between optimal group divisible packing and covering designs, Arts A1046 
11:10  11:35  Douglas Stinson (University of Waterloo), Combinatorial Aspects of Key Distribution for Sensor Networks, Arts A1046 
11:40  12:05  Karen Meagher (University of Regina), Covering arrays on graphs, Arts A1046 
Eric Mendelsohn: Colleagues and Descendants II (CM7)  
PrÃ©sident: Brett Stevens (Carleton University) Org: Peter Danziger (Ryerson University) et Brett Stevens (Carleton University)  
These minisymposia celebrate the influence and work of Eric Mendelsohn through his collaborators, students, and other colleagues. At age 1, Eric Mendelsohn was a registered participant at the inaugural 1945 Montreal meeting of the Canadian Mathematics Society. His activities and influence in discrete mathematics continue to this day. He was hired at the Department of Mathematics at the University of Toronto in 1970, where he has been full professor since 1982. He retired from the University in 2010, and is now professor emeritus. He is currently an adjunct professor with the department of Mathematics at Ryerson University, whose support we gratefully acknowledge. Eric has 94 publications, 55 coauthors, 13 official "descendants". He has been an important force in combinatorics and discrete mathematics over many years, his energy and vision have provided many important directions and insights.  
lundi 10 juin  
15:15  15:40  Robert Bailey (Ryerson University), Generalized packing designs with block size 5, Arts A1046 
15:45  16:10  Derek Corneil (University of Toronto), Graph searches and cocomparability graphs, Arts A1046 
16:15  16:40  Peter Dukes (University of Victoria), Designs of high dimension, Arts A1046 
16:45  17:10  Nabil Shalaby (Memorial University of Newfoundland), Skolem labelled graphs, old and new results, Arts A1046 
Eric Mendelsohn: Colleagues and Descendants III (CM9)  
PrÃ©sident: Peter Danziger (Ryerson University) Org: Peter Danziger (Ryerson University) et Brett Stevens (Carleton University)  
These minisymposia celebrate the influence and work of Eric Mendelsohn through his collaborators, students, and other colleagues. At age 1, Eric Mendelsohn was a registered participant at the inaugural 1945 Montreal meeting of the Canadian Mathematics Society. His activities and influence in discrete mathematics continue to this day. He was hired at the Department of Mathematics at the University of Toronto in 1970, where he has been full professor since 1982. He retired from the University in 2010, and is now professor emeritus. He is currently an adjunct professor with the department of Mathematics at Ryerson University, whose support we gratefully acknowledge. Eric has 94 publications, 55 coauthors, 13 official "descendants". He has been an important force in combinatorics and discrete mathematics over many years, his energy and vision have provided many important directions and insights.  
mardi 11 juin  
10:10  10:35  Aiden Bruen (Carleton University), Unimbeddable nets of small deficiency, Arts A1046 
10:40  11:05  Frantisek Franek (McMaster University), On the singularities of extremal periodic strings, Arts A1046 
11:10  11:35  Sebastian Raaphorst (University of Ottawa), The Lovasz Local Lemma and Variable Strength Covering Arrays, Arts A1046 
11:40  12:05  Ben Seamone (University de Montreal), Bounding a graph's weight choosability number, Arts A1046 
12:10  12:35  Daniela Silvesan (Memorial University of Newfoundland), Cyclic, Simple and Indecomposable ThreeFold Triple Systems, Arts A1046 
Finite Fields in Combinatorics I (CM14)  
PrÃ©sident: David Thomson (Carleton University) Org: Petr Lisonek (Simon Fraser University) et David Thomson (Carleton University)  
The areas of finite fields and combinatorics are strongly linked. The talks in this minisymposium highlight the versatility in the use of finite fields to construct interesting classes of combinatorial objects and prove results about them. Topics addressed in the talks include error control codes, finite geometries, planar functions, Costas and related arrays, sequences with good correlation properties, permutation polynomials, decomposition of polynomials, and more.  
mardi 11 juin  
15:15  15:40  Aiden Bruen (Carleton University), Dickson's theorem: applications and generalizations, Arts A1046 
15:45  16:10  Yue Zhou (OttovonGuericke University of Magdeburg), Planar functions over finite fields with characteristic two, Arts A1046 
16:15  16:40  Petr Lisonek (Simon Fraser University), Construction X for quantum errorcorrecting codes, Arts A1046 
16:45  17:10  Kenza Guenda (University of Victoria), The equivalency problem for cyclic combinatorial objects, Arts A1046 
17:15  17:40  Jane Wodlinger (University of Victoria), Structural properties of Costas arrays, Arts A1046 
Finite Fields in Combinatorics II (CM18)  
PrÃ©sident: Petr Lisonek (Simon Fraser University) Org: Petr Lisonek (Simon Fraser University) et David Thomson (Carleton University)  
The areas of finite fields and combinatorics are strongly linked. The talks in this minisymposium highlight the versatility in the use of finite fields to construct interesting classes of combinatorial objects and prove results about them. Topics addressed in the talks include error control codes, finite geometries, planar functions, Costas and related arrays, sequences with good correlation properties, permutation polynomials, decomposition of polynomials, and more.  
mercredi 12 juin  
10:10  10:35  Daniel Katz (California State University, Northridge), Weil Sums of Binomials with ThreeValued Spectra, Arts A1046 
10:40  11:05  Jing He (Carleton University), A new class of almost perfect sequences and a new family of Zero Correlation Zone sequences, Arts A1046 
11:10  11:35  Xiangdong Hou (University of South Florida), A Class of Permutation Binomials over Finite Fields, Arts A1046 
11:40  12:05  Mark Giesbrecht (University of Waterloo), Decomposition of additive polynomials and matrix similarity classes, Arts A1046 
12:10  12:35  David Thomson (Carleton University), On a conjecture of Golomb and Moreno, Arts A1046 
Galois geometries and applications I (CM20)  
PrÃ©sident: Jan De Beule (Ghent University) Org: Jan De Beule (Ghent University) et Petr Lisonek (Simon Fraser University)  
Galois geometries is the research field in which projective spaces over the finite fields, also called Galois fields, are investigated. This includes the study of their substructures and their links to other research areas. Many of these substructures are investigated for their geometrical importance, such as the quadrics and the Hermitian varieties, but many substructures are investigated because of their links to other research areas such as coding theory. This includes the link between arcs in Galois geometries and linear MDS codes. Recently, also links between random network coding and Galois geometries have been found. The techniques used in Galois geometries involve, next to geometrical techniques, also other techniques such as the polynomial method.
This minisymposium will discuss different aspects of Galois geometries. This includes theoretical results and links to coding theory.  
mercredi 12 juin  
15:15  15:40  Peter Sziklai (Eotvos Lorand University, Budapest, Hungary), The direction problem: old and new results, Science SN2105 
15:45  16:10  Qing Xiang (University of Delaware, USA), Constructions of difference sets and strongly regular graphs using cyclotomic classes, Science SN2105 
16:15  16:40  Brett Stevens (Carleton University, Canada), Linear feedback shift registers and covering arrays, Science SN2105 
16:45  17:10  Petr Lisonek (Simon Fraser University, Canada), Quantum codes from generalized quadrangles, Science SN2105 
17:15  17:40  Kathryn Haymaker (University of Nebraska  Lincoln, USA), Write once memory codes from finite geometries, Science SN2105 
Galois Geometries and Applications II (CM25)  
PrÃ©sident: Petr Lisonek (Simon Fraser University) Org: Jan De Beule (Ghent University) et Petr Lisonek (Simon Fraser University)  
Galois geometries is the research field in which projective spaces over the finite fields, also called Galois fields, are investigated. This includes the study of their substructures and their links to other research areas. Many of these substructures are investigated for their geometrical importance, such as the quadrics and the Hermitian varieties, but many substructures are investigated because of their links to other research areas such as coding theory. This includes the link between arcs in Galois geometries and linear MDS codes. Recently, also links between random network coding and Galois geometries have been found. The techniques used in Galois geometries involve, next to geometrical techniques, also other techniques such as the polynomial method. This minisymposium will discuss different aspects of Galois geometries. This includes theoretical results and links to coding theory.  
jeudi 13 juin  
10:10  10:35  Alfred Wassermann (University of Bayreuth, Germany), Construction of $q$analogs of Steiner systems, Science SN2105 
10:40  11:05  Michael Braun (University of Darmstadt, Germany), $q$Analog of Packing Designs, Science SN2105 
11:10  11:35  Maarten De Boeck (Ghent University, Belgium), The Erd\H{o}sKoRado problem for geometries, Science SN2105 
11:40  12:05  Sara Rottey (VUB (Vrije Universiteit Brussel), Belgium), The automorphism group of linear representations, Science SN2105 
12:10  12:35  Jan De Beule (Ghent University, Belgium), Constructing CameronLiebler line classes with large parameter, Science SN2105 
Geometric Representations of Graphs (CM10)  
Responsable et prÃ©sident: Steven Chaplick (Charles University, Prague, Czech Republic)  
Visualizations and representations of graphs by means of intersections or contacts of geometric objects have been widely investigated. Classical examples are interval graphs and Koebe circle representations. When representations are given they can sometimes be exploited in optimization problems. In many instances these problems are hard for general graphs but become polynomialtime solvable when restricted to intersection or contact graphs with a given representations. Another class of problems is to compute the representation or to decide whether it exists. In this minisymposium we highlight some recent developments in this active area at the intersection of graph theory and discrete geometry.  
mardi 11 juin  
10:10  10:35  Steven Chaplick (Charles University, Prague, Czech Republic), Max PointTolerance Graphs, Science SN2105 
10:40  11:05  Anna Lubiw (University of Waterloo, Waterloo, Canada), Morphing Planar Graph Drawings, Science SN2105 
11:10  11:35  Marcus Schaefer (DePaul University, Chicago, U.S.A.), Toward a Theory of Planarity: An algorithm for simultaneous planarity?, Science SN2105 
11:40  12:05  Torsten Ueckerdt (Karlsruhe Institute of Technology, Karlsruhe, Germany), Various Applications of L, Science SN2105 
12:10  12:35  Ryuhei Uehara (Japan Advanced Institute of Science and Technology, Nomi, Japan), The graph isomorphism problem on graphs with geometric representations, Science SN2105 
Graph Homomorphisms (CM2)  
Responsable et prÃ©sident: Pavol Hell (SFU)  
The speakers will focus on recent results concerning various aspects of graph homomorphisms  
lundi 10 juin  
10:10  10:35  Laszlo Egri (Hungarian Academy of Sciences, Budapest), List HColoring a Graph by Removing Few Vertices, Science SN2098 
10:40  11:05  Robert Samal (Charles University, Prague), Hedetniemi conjecture for strict vector chromatic number, Science SN2098 
11:10  11:35  Hamed Hatami (McGill University, Montreal), The entropy of randomfree graphons and properties, Science SN2098 
11:40  12:05  Jaroslav Nesetril (Charles University, Prague), Treedepth primer, Science SN2098 
12:10  12:35  Patrice Ossona de Mendez (L'Ecole des Hautes Etudes en Sciences Sociales, Paris), A first Intermediate class with limit object, Science SN2098 
Graph Structure and Algorithms (CM3)  
Responsable et prÃ©sident: Kathie Cameron (Wilfrid Laurier University)  
Often graphs arising in applications have special structure. This structure can sometimes be used to design efficient algorithms for problems that are hard in general. Clearly, special structure is needed to prove the existence of certain types of subgraphs which do not exist in more general graphs. In this minisymposium, we see four instances of efficient algorithms and existence theorems which exploit special structure, and one anomalous algorithmic problem which was solved by ignoring the special graph structure.  
lundi 10 juin  
10:10  10:35  Jessica Enright (University of Glasgow), On List Colouring and List Homomorphism of Permutation and Interval Graphs, Science SN2105 
10:40  11:05  Elaine Eschen (West Virginia University), Colored Graph Completion, Science SN2105 
11:10  11:35  R. Sritharan (University of Dayton), Hendry's conjecture holds for spider intersection graphs, Science SN2105 
11:40  12:05  Kathie Cameron (Wilfrid Laurier University), SameDegree Trees and Intermediate Trees, Science SN2105 
12:10  12:35  Katie Tsuji (University of Waterloo), Finding Monotone Path Systems in Regions with Holes, Science SN2105 
Graph Theory with Applications in Chemistry I (CM19)  
PrÃ©sident: Patrick Fowler (University of Sheffield) Org: Patrick Fowler (University of Sheffield) et Wendy Myrvold (University of Victoria)  
This session and the following linked session explore applications of graph theory to chemistry. Part I includes contributions on graph theory with applications to currents in molecules. Ballistic currents driven through molecules in an electric circuit and ring current circulations generated within aromatic molecules by a magnetic field are both of importance in chemistry and materials science, and both can be modelled using techniques from spectral graph theory and the theory of perfect matchings. Speakers will discuss some of these models and the connections between them.  
mercredi 12 juin  
10:10  10:35  Patrick W Fowler (University of Sheffield), Conjugated circuits, currents in benzenoids and equiaromaticity, Science SN2101 
10:40  11:05  Wendy Myrvold (University of Victoria), Models of Current Density Maps of Benzenoids, Science SN2101 
11:10  11:35  Matthias Ernzerhof (University of Montreal), The zerovoltage conductance of nanographenes: Simple rules and, Science SN2101 
11:40  12:05  Irene Sciriha (University of Malta), Molecular Graphs with Analogous Conducting Connections, Science SN2101 
12:10  12:35  Barry T Pickup (University of Sheffield), Effects of Pauli blockade on singlemolecule conduction, Science SN2101 
Graph Theory with Applications in Chemistry II (CM21)  
PrÃ©sident: Wendy Myrvold (University of Victoria) Org: Patrick Fowler (University of Sheffield) et Wendy Myrvold (University of Victoria)  
This session and the previous linked session explore applications of graph theory to chemistry. Part II includes contributions on graph theory with applications to molecular structure, stability and reactivity. Stability and properties of fullerenes and benzenoids are of theoretical and practical interest in chemistry, and are often modelled using theories based on perfect matchings and graph spectra. Talks will include discussion of two models of fullerene (and benzenoid) stability based on the ideas proposed by Clar and Fries, extension of graph spectral models to saturated systems, and new models of chemical reactivity.  
mercredi 12 juin  
15:15  15:40  Elizabeth Hartung (Massachusetts College of Liberal Arts), The Clar Structures of a Fullerene, Science SN2101 
15:45  16:10  Jack E Graver (Syracuse University), The Fries Structures of a fullerene, Science SN2101 
16:15  16:40  Craig E Larson (Virginia Commonwealth University), Eigenvalues of Saturated Hydrocarbons, Science SN2101 
16:45  17:10  Nico Van Cleemput (University of Gent), Spherical Tilings by Congruent Quadrangles, Science SN2101 
17:15  17:40  Douglas J Klein (Texas A&M University at Galveston), Substitutionreaction posets in chemistry, Science SN2101 
Gray Codes and Universal Cycles (CM15)  
PrÃ©sident: Joe Sawada (University of Guelph) Org: Joe Sawada (University of Guelph) et Aaron Williams (McGill University)  
The ability to efficiently generate all possible instances of a particular combinatorial object (permutations, combinations, trees, necklaces, etc) is of practical importance to many areas of scientific research. It is the primary topic in Knuth's most recent addition to his series ``The Art Of Computer Programming''. This session will focus on several key aspects in this area including:
(Greedy) Gray codes, Universal cycles, Random generation. In particular, attendees may learn simple ways to construct their ``family tree'' and how to ``greedily flip pancakes''.  
mardi 11 juin  
15:15  15:40  Joe Sawada (University of Guelph), An overview of Combinatorial Generation, Science SN2105 
15:45  16:10  Aaron Williams (McGill University), Iterative Gray Codes, Science SN2105 
16:15  16:40  Ryuhei Uehara (Japan Advanced Institute of Science and Technology), On generation of graphs with geometric representations, Science SN2105 
16:45  17:10  Xi Sisi Shen (McGill University), A "Hot Potato" transposition Gray code for permutations, Science SN2105 
Hypergraphs (CM22)  
PrÃ©sident: Amin Bahmanian (University of Ottawa) Org: Amin Bahmanian et Mateja Sajna (University of Ottawa)  
In the last decade, hypergraph theory has emerged as a powerful mathematical tool in a variety of reallife applications. However, in spite of its remarkable developments, the theory of hypergraphs has not yet given rise to extensive literature comparing to the theory of graphs. For example, very little is known about edge decompositions of hypergraphs, even for special cases. Perhaps the best evidence for the difficulty of questions about hypergraphs is Sylvester's Problem, which asks about the existence of a 1factorization of the complete uniform hypergraph. It took 120 years before Baranyai finally solved this problem.
The goal of this minisymposium is to bring together experts in various areas of hypergraph theory. The main areas of interest are edge colorings, edge decompositions, amalgamations, detachments, and embeddings.  
mercredi 12 juin  
15:15  15:40  Shonda Gosselin (University of Winnipeg), Cyclic decompositions of complete and complete multipartite uniform hypergraphs, Science SN2098 
15:45  16:10  Andrzej Czygrinow (Arizona State University), Loose cycles in 3uniform hypergraphs, Science SN2098 
16:15  16:40  Amin Bahmanian (University of Ottawa), 2edgeconnected fair detachments of $(\leq 3)$graphs, Science SN2098 
16:45  17:10  Imdadullah Khan (Umm Al Qura University), Perfect matchings in uniform hypergraph with large vertex degree, Science SN2098 
17:15  17:40  Mateja Sajna (University of Ottawa), Euleriantype properties of hypergraphs, Science SN2098 
Independence Number: Theory and Applications I. (CM26)  
PrÃ©sident: Craig Larson (Virginia Commonwealth University) Org: Ermelinda DeLaVina (University of HoustonDowntown) et Craig Larson (Virginia Commonwealth University)  
Researchers will present recent work related to the independence structure of a graph. Several speakers discuss advances in the investigation of wellcovered graphs, graphs where every maximal independent set is a maximum independent set. Other research includes new bounds for the independence number, new bounds for the number of independent structures, and theory and problems related to the efficient computation of the independence number.  
jeudi 13 juin  
10:10  10:35  Michael D. Plummer (Vanderbilt University), A Problem On Wellcovered Graphs, Science SN2098 
10:40  11:05  Art Finbow (Saint Mary's University), On WellCovered Planar Triangulations, Science SN2098 
11:10  11:35  William Staton (University of Mississippi), Independence Polynomials of kTrees, Science SN2098 
11:40  12:05  David Tankus (Ariel University of Samaria), Weighted WellCovered Graphs without Cycles of Lengths 4, 5, and 6, Science SN2098 
12:10  12:35  Ermelinda DeLaVina (University of HoustonDowntown), Graffiti.pc on Independence, Science SN2098 
Independence Number: Theory and Applications II. (CM28)  
PrÃ©sident: Ermelinda DeLaVina (University of HoustonDowntown) Org: Ermelinda DeLaVina (University of HoustonDowntown) et Craig Larson (Virginia Commonwealth University)  
Researchers will present recent work related to the independence structure of a graph. Several speakers discuss advances in the investigation of wellcovered graphs, graphs where every maximal independent set is a maximum independent set. Other research includes new bounds for the independence number, new bounds for the number of independent structures, and theory and problems related to the efficient computation of the independence number.  
jeudi 13 juin  
15:15  15:40  Doug Rall (Furman University), On Maximal Independent Sets in Cartesian Products, Science SN2098 
15:45  16:10  Bert Hartnell (Saint Mary's University), Eternal Domination with Independent Guards, Science SN2098 
16:15  16:40  Jochen Harant (Ilmenau University of Technology), Packing of isomorphic induced independent subgraphs, Science SN2098 
16:45  17:10  Craig Larson (Virginia Commonwealth University), The Independence Number Project, Science SN2098 
17:15  17:40  Ryan Pepper (University of HoustonDowntown), Recent Results on kindependence in graphs, Science SN2098 
Nested Recurrence Relations (CM4)  
Responsable et prÃ©sident: Frank Ruskey (University of Victoria)  
Hofstadter introduced the recurrence
$Q(n)=Q(nQ(n1))+Q(nQ(n2))$, an example of a \textit{nested
recurrence relation} (or NRR) because it has a subexpression of
the form $â€¦Q(â€¦Q(â€¦)â€¦)â€¦$. Other than composition, the only operations
that are used are addition/subtraction.
Recently there has been a flurry of activity in trying to understand and ``solve'' NRRs. Some NRRs have a solution and combinatorial interpretations, while others seemingly do not. It is still unknown whether $Q(n)$ is defined for all $n$. On the other hand, the recurrence $T(n)=T(n1T(n1))+T(n2T(n2))$ with $T(1)=T(2)=T(3)=1$, the number $T(n)$ counts the maximum number of leaves at the lowest level in a $n$node binary tree. There are many recent results that show that NRRs arise from natural counting problems in certain classes of highly structured infinite trees. There are undecidable NRRs and some that are related to automatic sequences. This minisymposium will introduce NRRs, present some recent results, and offer tantalizing open problems.  
lundi 10 juin  
10:10  10:35  Steve Tanny (University of Toronto), An Invitation to Nested Recurrence Relations, Science SN2101 
10:40  11:05  Mustazee Rahman (University of Toronto), Nested Recursions, Simultaneous Parameters and Tree Superpositions, Science SN2101 
11:10  11:35  Jeff Shallit (University of Waterloo), Automata and nested recurrences, Science SN2101 
11:40  12:05  Marcel Celaya (McGill University), Morphic Words and Nested Recurrence Relations, Science SN2101 
12:10  12:35  Frank Ruskey (University of Victoria), An undecidable nested recurrence relation, Science SN2101 
Partitioning Graphs into Independent Sets and Cliques (CM11)  
Responsable et prÃ©sident: Dennis D.A. Epple (University of Victoria)  
A natural generalization of graph colourings is to consider partitions of the vertex set of graphs into independent sets and cliques. This idea gives rise to a wide field of topics including $(k,l)$colourings, split graphs, the cochromatic number, and matrix partitions. This minisymposium features a broad selection of current research in the area.  
mardi 11 juin  
10:10  10:35  Dennis D.A. Epple (University of Victoria), Young diagrams for $(k,l)$colourings, Science SN2098 
10:40  11:05  TÄ±naz Ekim (BoÄŸaziÃ§i University), Defective Cocolorings, Science SN2098 
11:10  11:35  Juraj Stacho (University of Warwick), Stable$\Pi$ partitions of graphs, Science SN2098 
11:40  12:05  Pavol Hell (Simon Fraser University), Matrix partitions, Science SN2098 
12:10  12:35  Mayssam Mohammadi Nevisi (Simon Fraser University), Counting Partitions of Graphs, Science SN2098 