
Please note that schedules are subject to change without notice, particularly changes within a given session.
Algebraic Combinatorics (IM2)  
Organizer and Chair: Steph Van Willigenburg (University of British Columbia)  
Algebraic combinatorics is a vibrant area whose results and tools in both algebra and combinatorics impact other areas such as representation theory, algebraic geometry and quantum physics. This minisymposium will showcase a variety of the latest results and applications.  
Monday June 10  
15:15  15:40  Drew Armstrong (University of Miami), Maximal Chains of Parabolic Subgroups, Arts A1043 
15:45  16:10  Brendon Rhoades (UCSD), Extending the parking space, Arts A1043 
16:15  16:40  Rosa Orellana (Dartmouth), The quasipartition algebra, Arts A1043 
16:45  17:10  Hugh Thomas (University of New Brunswick), A reflection group perspective on cvectors, Arts A1043 
17:15  17:40  Abraham Broer (Université de Montréal), Algorithms of making linebundles on cotangent bundles of complete homogeneous spaces more positive., Arts A1043 
Algorithmic Methods in Comparative Genomics (IM6)  
Organizer and Chair: Max Alekseyev (University of South Carolina)  
Comparative genomics studies similarities and differences in genome structure and function across different species to yield insights into evolution. Comparative genomics heavily relies on computation to process the huge amount of information contained in genomic data. This minisymposium features talks on algorithmic methods in comparative genomics from experts in the field.  
Wednesday June 12  
15:15  15:40  Bahar Behsaz (Simon Fraser University), Turing Universality of DNA SelfAssembly Models at Temperature 1, Arts A1043 
15:45  16:10  Patricia Evans (University of New Brunswick), Finding RNA structure motifs, Arts A1043 
16:15  16:40  David Sankoff (University of Ottawa), Fractionation, rearrangement, consolidation and reconstruction, Arts A1043 
16:45  17:10  Jijun Tang (University of South Carolina), Binary Encoding and Genome Rearrangement Analysis, Arts A1043 
17:15  17:40  Max Alekseyev (University of South Carolina), Genome rearrangements: when intuition fails, Arts A1043 
Analytic Combinatorics (IM3)  
Organizer and Chair: Alfredo Viola (Universidad de la República, Uruguay)  
As defined in the book ``Analytic Combinatorics'' by Philippe Flajolet and Robert Sedgewick (2009): "Analytic combinatorics aims to enable precise quantitative predictions of the properties of large combinatorial structures. The theory has emerged over recent decades as essential both for the analysis of algorithms and for the study of scientific models in many disciplines, including probability theory, statistical physics, computational biology and information theory". This minisymposium aims at presenting new results and applications in the area.  
Tuesday June 11  
10:10  10:35  Marcos Kiwi (Universidad de Chile), Towards the distribution of the size of the largest noncrossing matchings in random bipartite graphs, Arts A1043 
10:40  11:05  Daniele Gardy (Université de Versailles SaintQuentin), Some problems related to the enumeration of lambdaterms, Arts A1043 
11:10  11:35  Julien Clement (GREYC, CNRS), A general framework for the realistic analysis of sorting and searching algorithms. Application to some popular algorithms, Arts A1043 
11:40  12:05  Brigitte Vallee (GREYC, CNRS), Typical depth of a digital search tree built on a general source, Arts A1043 
12:10  12:35  Alois Panholzer (Technische Universität Wien), Occurrences of exactly solvable PDEs in combinatorial problems, Arts A1043 
Applications of Generating Functions (CM5)  
Organizer and Chair: Alois Panholzer (Technische Universität 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.  
Monday June 10  
15:15  15:40  Bernhard Gittenberger (Technische Universität 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 República), 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)  
Chair: Chris Soteros (University of Saskatchewan) Org: Marni Mishna (Simon Fraser University), Chris Soteros (University of Saskatchewan) and 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.  
Wednesday June 12  
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)  
Chair: Marni Mishna (Simon Fraser University) Org: Marni Mishna (Simon Fraser University), Chris Soteros (University of Saskatchewan) and 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.  
Thursday June 13  
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 
Broadcast and Algorithms (CT13)  
Chair: Hovhannes Harutyunyan (Concordia University)  
Thursday June 13  
15:15  15:40  Jan Goedgebeur (Ghent University), House of Graphs: a database of interesting graphs, Arts A1049 
15:45  16:10  Patrick Gaskill (Virginia Commonwealth University), The Independence Number Project: Difficult Graphs and Conjectures, Arts A1049 
16:15  16:40  Hovhannes Harutyunyan (Concordia University), Diametral Broadcast Graphs, Arts A1049 
16:45  17:10  Puspal Bhabak (Concordia University, Montreal, Canada), Broadcast Problem in kpaths Connected at Two Junctions, Arts A1049 
17:15  17:40  Sirma Cagil Altay (Concordia University), Broadcasting on Kn{\"o}del graphs and minimum average broadcast graphs, Arts A1049 
Chromatic Graph Theory (CM6)  
Organizer and Chair: 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.  
Monday June 10  
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 
Combinatorics and Geometry of Linear Optimization (IM4)  
Organizer and Chair: Antoine Deza (McMaster University)  
Optimization has long been a source of inspiration and applications for geometers, and similarly, discrete and convex geometry have provided foundations for many efficient optimization techniques. Combinatorics forms an intrinsic part of optimization, and there is a rich interplay between geometry and combinatorics. The intent of the minisymposium is to bring together geometers and combinatorial and continuous optimizers.  
Tuesday June 11  
15:15  15:40  Henry Wolkowicz (University of Waterloo), Taking advantage of Degeneracy and Special Structure in Linear Cone Optimization, Arts A1043 
15:45  16:10  Nathan Krislock (University of Britsih Columbia), BiqCrunch: a semidefinitebased solver for binary quadratic problems, Arts A1043 
16:15  16:40  Frauke Liers (Universität ErlangenNürnberg), Geometry of Network Design with Certain and Uncertain Demands, Arts A1043 
16:45  17:10  Manuel Vieira (Universidade Nova Lisboa), Extracting information of unsatisfiable formulas using Semidefinite certificates of infeasibility, Arts A1043 
17:15  17:40  Antoine Deza (McMaster University), Combinatorial, computational, and geometric approaches to the colourful simplicial depth, Arts A1043 
Complexity and Reductions (CT14)  
Chair: Alejandro Erickson (University of Victoria)  
Thursday June 13  
15:15  15:40  Alejandro Erickson (University of Victoria), Domino tatami cover is NPcomplete, Arts A1045 
15:45  16:10  Bundit Laekhanukit (McGill University), Parameters of TwoProverOneRound Game and The Hardness of Connectivity Problems, Arts A1045 
16:15  16:40  Andrei Bulatov (Simon Fraser University), Counting CSPs and Datalog fixed points, Arts A1045 
16:45  17:10  Ross Churchley (Simon Fraser University), Algorithms and obstructions for treetransverse matchings, Arts A1045 
Cycle Decompositions of Graphs I (CM12)  
Chair: Mateja Sajna (University of Ottawa) Org: Andrea Burgess (Ryerson University) and 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.  
Tuesday June 11  
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)  
Chair: Andrea Burgess (Ryerson University) Org: Andrea Burgess (Ryerson University) and 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.  
Wednesday June 12  
10:10  10:35  Marco Buratti (Università 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)  
Organizer and Chair: 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.  
Tuesday June 11  
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 
Design Theory (IM9)  
Organizer and Chair: Ian Wanless (Monash University)  
This minisymposium will cover the existence, enumeration and properties of combinatorial designs such as Latin squares, Steiner triple systems, Hadamard matrices and so on. Such designs are widely used in statistical analysis, communication technologies and scheduling problems, to name just a few areas.  
Thursday June 13  
15:15  15:40  Daniel Horsley (Monash University), Embeddings of partial Steiner triple systems with few triples, Arts A1043 
15:45  16:10  Hadi Kharaghani (University of Lethbridge), Biangular lines in $\mathbb{R}^n$, Arts A1043 
16:15  16:40  Joy Morris (University of Lethbridge), Generalised $n$gons with symmetry conditions, Arts A1043 
16:45  17:10  David Pike (Memorial University of Newfoundland), Cycle Extensions in PBD BlockIntersection Graphs, Arts A1043 
17:15  17:40  Doug Stones (Dalhousie University), Enumeration and symmetries of partial Latin rectangles, Arts A1043 
Designs (CT11)  
Chair: Mathieu Loiselle (Concordia University)  
Thursday June 13  
10:10  10:35  Richard Anstee (UBC Mathematics), Forbidden Families of Configurations, Arts A1045 
10:40  11:05  Ian Wanless (Monash University), Nonextendible latin cubes, Arts A1045 
11:10  11:35  Raúl Falcón (University of Seville), Concurrence designs based on partial Latin rectangles autotopisms, Arts A1045 
11:40  12:05  Mathieu Loiselle (Concordia University), Design's Inspired by the ErdösKoRado Theorem, Arts A1045 
12:10  12:35  Aneesh Hariharan (University of Washington), nGraceful Blocks, Arts A1045 
Discrete Math Coast to Coast: Newfoundland and the West (CM24)  
Chair: 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.  
Thursday June 13  
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)  
Chair: 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.  
Thursday June 13  
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)  
Organizer and Chair: 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.  
Tuesday June 11  
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 
Enumeration I (CT7)  
Chair: Valentin Féray (CNRS, Université Bordeaux 1)  
Tuesday June 11  
15:15  15:40  Daniel Krenn (TU Graz, Austria), The Width of ``Canonical'' Trees and of Acyclic Digraphs, Arts A1049 
15:45  16:10  Mohan Gopaladesikan (Purdue University), Building Random Trees from Blocks, Arts A1049 
16:15  16:40  Stephen Melczer (Simon Fraser University), Enumerating Lattice Walks in the Quarter Plane, Arts A1049 
16:45  17:10  Max Alekseyev (University of South Carolina), Unlabeled Motzkin numbers, Arts A1049 
Enumeration II (CT15)  
Chair: MarieLouise Bruner (Vienna University of Technology, Austria)  
Thursday June 13  
15:15  15:40  Valentin Féray (CNRS, Université Bordeaux 1), Multiparameter hook formula for labelled trees, Science SN2105 
15:45  16:10  José Plínio Santos (State University of CampinasUNICAMPBrazil), Further Applications of the twoline array for representing partitions, Science SN2105 
16:15  16:40  Joon Yop Lee (POSTECH), Eulerian and Stirling numbers over multisets, Science SN2105 
Enumerative Combinatorics (IM1)  
Organizer and Chair: Marni Mishna (Simon Fraser University)  
Developments in enumerative combinatorics clarify connections between classes and can help us understand the large scale behaviour. This session explores recent work of both theoretical and applied interest, with an emphasis on bijective connections, and asymptotic enumeration.  
Monday June 10  
10:10  10:35  Sergi Elizalde (Dartmouth College), Bijections for lattice paths between two boundaries, Arts A1043 
10:40  11:05  Bruce Sagan (Michigan State University), A factorization theorem for $m$rook placements, Arts A1043 
11:10  11:35  Alejandro Morales (LaCIM, UQAM), Counting matrices over finite fields with zeroes on Rothe diagrams, Arts A1043 
11:40  12:05  Mathilde Bouvel (CNRS/LaBRI Bordeaux I), Operators of equivalent sorting power and related Wilfequivalences, Arts A1043 
12:10  12:35  Markus Nebel (University of Kaiserslautern), The Combinatorics of RNA in the Polymere Zeta Model, Arts A1043 
Eric Mendelsohn: Colleagues and Descendants I (CM1)  
Chair: Brett Stevens (Carleton University) Org: Peter Danziger (Ryerson University) and 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.  
Monday June 10  
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)  
Chair: Brett Stevens (Carleton University) Org: Peter Danziger (Ryerson University) and 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.  
Monday June 10  
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)  
Chair: Peter Danziger (Ryerson University) Org: Peter Danziger (Ryerson University) and 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.  
Tuesday June 11  
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 
Extremal Combinatorics (IM8)  
Organizer and Chair: Dhruv Mubayi (University of Illinois at Chicago)  
Extremal combinatorics studies the extreme value of some parameter over a class of combinatorial objects. This minisymposium will cover extremal graph and hypergraph theory, a subject that began with Turans theorem from graph theory over 70 years ago. Modern extremal combinatorics showcases tools from diverse areas including algebra, probability, number theory, analysis, and also has applications in these areas.  
Thursday June 13  
10:10  10:35  Penny Haxell (University of Waterloo), Extremal hypergraphs for packing and covering, Arts A1043 
10:40  11:05  John Lenz (University of Illinois at Chicago), Hypergraph Quasirandomness, Arts A1043 
11:10  11:35  Sergey Norin (McGill University), Forcing multidimensional graphons, Arts A1043 
11:40  12:05  Mathias Schacht (Universität Hamburg), Sharp threshold vor van der Waerden's theorem, Arts A1043 
12:10  12:35  Jacques Verstraete (UCSD), Random Independent Sets in Hypergraphs, Arts A1043 
Finite Fields in Combinatorics I (CM14)  
Chair: David Thomson (Carleton University) Org: Petr Lisonek (Simon Fraser University) and 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.  
Tuesday June 11  
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)  
Chair: Petr Lisonek (Simon Fraser University) Org: Petr Lisonek (Simon Fraser University) and 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.  
Wednesday June 12  
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)  
Chair: Jan De Beule (Ghent University) Org: Jan De Beule (Ghent University) and 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.  
Wednesday June 12  
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)  
Chair: Petr Lisonek (Simon Fraser University) Org: Jan De Beule (Ghent University) and 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.  
Thursday June 13  
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)  
Organizer and Chair: 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.  
Tuesday June 11  
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 Colouring (CT12)  
Chair: Christopher Martin van Bommel (St. Francis Xavier University)  
Thursday June 13  
10:10  10:35  Ignacio M Pelayo (Universitat Politècnica de Catalunya, Barcelona, Spain), NordhausGaddumtype results for locating domination, Arts A1049 
10:40  11:05  Christopher Martin van Bommel (St. Francis Xavier University), An Extension of Parity Vertex Colourings, Arts A1049 
11:10  11:35  Hediyeh Mashhadi Avaz Tehrani (Brock University), Edgechoosability of Planar Graphs, Arts A1049 
11:40  12:05  James Carraher (University of NebraskaLincoln), Finding compatible circuits in eulerian digraphs., Arts A1049 
12:10  12:35  Aysel Erey (Dalhousie University), Chromatic Polynomials, Arts A1049 
Graph Homomorphisms (CM2)  
Organizer and Chair: Pavol Hell (SFU)  
The speakers will focus on recent results concerning various aspects of graph homomorphisms  
Monday June 10  
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)  
Organizer and Chair: 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.  
Monday June 10  
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 (IM5)  
Organizer and Chair: Matthias Kriesell (Universität Hamburg)  
Wednesday June 12  
10:10  10:35  Johannes Carmesin (Universität Hamburg), Canonical tree decomposition into highly connected pieces, Arts A1043 
10:40  11:05  Bojan Mohar (Simon Fraser University/University of Ljubljana), On median eigenvalues of graphs, Arts A1043 
11:10  11:35  Jonathan Noel (McGill University), Choosability of Graphs with Bounded Order: Ohba's Conjecture and Beyond, Arts A1043 
11:40  12:05  Robert Šámal (Charles University), Cyclecontinuous mappings  order structure, Arts A1043 
12:10  12:35  Gábor Simonyi (Hungarian Academy of Sciences), Comparing the local chromatic number of a digraph and its underlying undirected graph, Arts A1043 
Graph Theory I (CT1)  
Chair: Odile Marcotte (CRM and UQAM)  
Monday June 10  
10:10  10:35  Odile Marcotte (CRM and UQAM), On the maximum orders of an induced forest, an induced tree, and a stable set, Arts A1045 
10:40  11:05  Paul Wenger (Rochester Institute of Technology), Saturated Subgraphs of Multipartite Graphs, Arts A1045 
11:10  11:35  Matthias Kriesell (Technical University Ilmenau), On the Structure of Graphs of Minimum Degree at least Four, Arts A1045 
11:40  12:05  Sarada Herke (The University of Queensland), Perfect 1factorisations of circulant graphs of degree 4, Arts A1045 
12:10  12:35  Mustapha Aouchiche (GERAD and HEC), Two Laplacians for the Distance Matrix of a Graph, Arts A1045 
Graph Theory II (CT2)  
Chair: Mark Ellingham (Vanderbilt University)  
Monday June 10  
15:15  15:40  Mark Ellingham (Vanderbilt University), Hamiltonicity of 3connected planar graphs with a forbidden minor, Arts A1045 
15:45  16:10  Nishad Kothari (University of Waterloo), Characterizing prismfree planar bricks., Arts A1045 
16:15  16:40  Jan Foniok (Queen's University), Right adjoints of Pultr functors, Arts A1045 
16:45  17:10  Steven Schluchter (George Washington University), Ordinary voltage graphs, pseudosurfaces, and derived cellular homology., Arts A1045 
17:15  17:40  Ágnes Tóth (Alfréd Rényi Institute of Mathematics, Budapest), The asymptotic value of the independence ratio for the direct graph power, Arts A1045 
Graph Theory III (CT8)  
Chair: Danielle Cox (Dalhousie University)  
Tuesday June 11  
15:15  15:40  Danielle Cox (Dalhousie University), All Terminal Reliability and Optimality, Arts A1045 
15:45  16:10  Lucas Mol (Dalhousie University), On the uniformity dimension of hypergraphs, Arts A1045 
16:15  16:40  Krystal Guo (Simon Fraser University), Simple eigenvalues of vertextransitive graphs and digraphs, Arts A1045 
16:45  17:10  Sadegheh Haghshenas (Memorial University of Newfoundland), Spectrum of Packing and Covering of the Complete Graph with Stars, Arts A1045 
17:15  17:40  Terry McKee (Wright State University, Dayton Ohio, USA), Requiring Pairwise Nonadjacent Chords in Cycles, Arts A1045 
Graph Theory IV (CT10)  
Chair: Susanna Ferreri (Brock University)  
Wednesday June 12  
15:15  15:40  Susanna Ferreri (Brock University), ACYCLIC 5CHOOSABLILITY OF PLANAR GRAPH WITHOUT ADJACENT SHORT CYCLES, Arts A1045 
15:45  16:10  Asiyeh Sanaei (Brock University), Threecolourability of planar graphs without 5cycles and triangular 3 and 6cycles, Arts A1045 
16:15  16:40  Henry Martyn Mulder (Econometrisch Instituut, Erasmus Universiteit), Location functions on graphs: why is anonymity an issue?, Arts A1045 
16:45  17:10  David Richter (Western Michigan University), Combinatorial gluings of outerplanar graphs, Arts A1045 
17:15  17:40  Michael Barrus (Brigham Young University), Realization polytopes for the degree sequence of a graph, Arts A1045 
Graph Theory with Applications in Chemistry I (CM19)  
Chair: Patrick Fowler (University of Sheffield) Org: Patrick Fowler (University of Sheffield) and 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.  
Wednesday June 12  
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)  
Chair: Wendy Myrvold (University of Victoria) Org: Patrick Fowler (University of Sheffield) and 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.  
Wednesday June 12  
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)  
Chair: Joe Sawada (University of Guelph) Org: Joe Sawada (University of Guelph) and 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''.  
Tuesday June 11  
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)  
Chair: Amin Bahmanian (University of Ottawa) Org: Amin Bahmanian and 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.  
Wednesday June 12  
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)  
Chair: Craig Larson (Virginia Commonwealth University) Org: Ermelinda DeLaVina (University of HoustonDowntown) and 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.  
Thursday June 13  
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)  
Chair: Ermelinda DeLaVina (University of HoustonDowntown) Org: Ermelinda DeLaVina (University of HoustonDowntown) and 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.  
Thursday June 13  
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 
Matroids, Codes and Numbers (CT5)  
Chair: Daryl Funk (Simon Fraser University)  
Tuesday June 11  
10:10  10:35  Daryl Funk (Simon Fraser University), Unique graph representations of bias matroids, Arts A1049 
10:40  11:05  Max Alekseyev (University of South Carolina), Integral points on biquadratic curves and nearmultiples of squares in Lucas sequences, Arts A1049 
11:10  11:35  Attila Sali (Alfréd Rényi Institute of Mathematics, Hungarian Academy of Sciences), A note on binary Armstrong codes, Arts A1049 
11:40  12:05  Fanxuan Zeng (Universitat Autonoma de Barcelona), On the minimum distance of qary nonlinear codes, Arts A1049 
Nested Recurrence Relations (CM4)  
Organizer and Chair: 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 $…Q(…Q(…)…)…$. 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.  
Monday June 10  
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 
Optimization (CT6)  
Chair: Bruce Shepherd (McGill University)  
Tuesday June 11  
10:10  10:35  Bruce Shepherd (McGill University), Almosttight Bounds for Online Vector Bin Packing, Arts A1045 
10:40  11:05  Tom McCormick (UBC Sauder School of Business), A parametric min cut approximation algorithm for network inhibition, Arts A1045 
11:10  11:35  Ahmad Abdi (University of Waterloo), Integer flows in binary matroids, Arts A1045 
11:40  12:05  Zhihan Gao (Department of Combinatorics and Optimization, University of Waterloo), An LPbased 3/2approximation algorithm for the graphic st path TSP, Arts A1045 
12:10  12:35  John Goldwasser (West Virginia University), Maximum density of exact copies of a subgraph of the dcube in the ncube, Arts A1045 
Partitioning Graphs into Independent Sets and Cliques (CM11)  
Organizer and Chair: 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.  
Tuesday June 11  
10:10  10:35  Dennis D.A. Epple (University of Victoria), Young diagrams for $(k,l)$colourings, Science SN2098 
10:40  11:05  Tınaz Ekim (Boğaziçi 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 
Popular Lecture  
This lecture is sponsored by AARMS.  
Wednesday June 12  
20:00  21:00  Robert Bosch (Oberlin College), Opt Art, Bruneau IIC2001 
Probabilistic Combinatorics (IM7)  
Organizer and Chair: Mike Molloy (University of Toronto)  
This minisymposium will cover areas related to random graphs and the probabilistic method. These subjects were pioneered by Erdos and Renyi more than 50 years ago. By now, they have a major impact throughout combinatorics as well as in other fields such as physics and computer science.  
Wednesday June 12  
15:15  15:40  Bruce Reed (McGill University), Variants of the ErdosSos Conjecture, Arts A1046 
15:45  16:10  Tom Bohman (Carnegie Mellon University), Selfcorrecting estimates for the triangle free process, Arts A1046 
16:15  16:40  Amin CojaOghlan (Goethe University Frankfurt/Main), Chasing the kSAT threshold, Arts A1046 
16:45  17:10  Mike Molloy (University of Toronto), Clusters of solutions to random linear equations, Arts A1046 
17:15  17:40  David Galvin (University of Notre Dame), Colouring regular bipartite graphs, cubes and grids, Arts A1046 
Ramsey Theory and Extremal Combinatorics (CT16)  
Chair: Steve Butler (Iowa State University)  
Thursday June 13  
15:15  15:40  Steve Butler (Iowa State University), Unrolling residues to avoid progressions, Science SN2101 
15:45  16:10  Andrzej Dudek (Western Michigan University), On generalized Ramsey numbers of Erd\H{o}s and Rogers, Science SN2101 
16:15  16:40  Stanisław Radziszowski (Rochester Institute of Technology), New Computational Bounds for Ramsey Numbers $R(3,K_ke)$, Science SN2101 
16:45  17:10  Liana Yepremyan (McGill University), Sparse halves in dense trianglefree graphs, Science SN2101 
17:15  17:40  Nana Li (Georgia State University), Union Closed Conjecture, Science SN2101 
Random Graphs (CT3)  
Chair: Pu Gao (University of Toronto)  
Monday June 10  
15:15  15:40  Pu Gao (University of Toronto), Change of limiting distributions of the number of large matchings, Science SN2105 
15:45  16:10  Cristiane M. Sato (University of Waterloo), On the robustness of random kcores, Science SN2105 
16:15  16:40  Deepak Bal (Carnegie Mellon University), Packing Tree Factors in Random and PseudoRandom Graphs, Science SN2105 
16:45  17:10  Florian Lehner (Graz University of Technology), Automorphism breaking in locally finite graphs, Science SN2105 
17:15  17:40  Katy Beeler (Wake Forest University), Deterministic walks, fairness, and choice, Science SN2105 
Visibility and Geometry (CT9)  
Chair: Suzanne Seager (Mount Saint Vincent University)  
Wednesday June 12  
10:10  10:35  Suzanne Seager (Mount Saint Vincent University), Locating a Robber on a Caterpillar, Arts A1045 
10:40  11:05  Hamideh Vosoughpour (University of Waterloo), Cops and Robbers in a Polygon, Arts A1045 
11:10  11:35  Bill Kinnersley (Ryerson University), How long does it take to catch a robber?, Arts A1045 
11:40  12:05  Khalegh Mamakani (University of Victoria), Simple symmetric Venn diagrams with 11 and 13 curves, Arts A1045 
12:10  12:35  Bette Bultena (University of Victoria), Minimum Area Polyomino Venn Diagrams, Arts A1045 
Words and Recurrences (CT4)  
Chair: Lowell Abrams (The George Washington University)  
Monday June 10  
15:15  15:40  Lowell Abrams (The George Washington University), A Family of NimLike Arrays: The Locator Theorem, Arts A1049 
15:45  16:10  Mousavi Haji Seyyed Hamoon (University of Waterloo), Repetition Avoidance in Circular Factors, Arts A1049 
16:15  16:40  Sahand Saba (University of Victoria), NonTrivial Decidable Nested Recurrence Relations, Arts A1049 
16:45  17:10  Russell Hendel (Towson University), Ruskey's Open Problem on Hofstadter's $Q$ Function, Arts A1049 