Every week or two during the Fall and Winter semesters we have a Combinatorics Seminar. Refreshments are frequently provided.
Speakers and topics for the present semester (and recent semesters) are shown below.
Presentations listed in italics were given as Colloquia.


Date  Speaker  Topic 
Friday, 2 November 
Gena Hahn, Universite de Montreal  Cops and robbers on graphs  finite and infinite 


Date  Speaker  Topic 
Friday, 29 June  Daniel Horsley, Monash University  Compressed sensing and hash families 


Date 
Speaker  Topic 
Wednesday, 14 March  Ryan Tifenbach, Memorial University of Newfoundland  Spectral graph theory I 
Wednesday, 21 March  Rebecca Milley, Dalhousie University  Lessons in Losing: An Introduction to Misere Game Theory 
Wednesday, 28 March  Ryan Tifenbach, Memorial University of Newfoundland  Spectral graph theory II 


Date 
Speaker  Topic 
Wednesday, 23 March  Jared Howell, Memorial University of Newfoundland  The Intersection of Latin Squares 


Date  Speaker  Topic 
Tuesday, 31 August  Colin Reid, McMaster University  Tchromatic index for Steiner S(2; k; v)s 


Date 
Speaker  Topic 
Monday, 15 February 
Robert Bailey, University of Regina  Hamiltonian decompositions of hypergraphs 
Friday, 26 February 
Andrea Burgess, Memorial University of Newfoundland  Cycle decompositions of some families of graphs 
Friday, 05 March 
Daniel Horsley, Memorial University of Newfoundland  Nimber Theory: Impartial Combinatorial Games  I 
Friday, 12 March 
Daniel Horsley, Memorial University of Newfoundland  Nimber Theory: Impartial Combinatorial Games  II 
Friday, 09 April 
Robert Gallant, Sir Wilfred Grenfell College  Finding discrete logarithms using additional information 


Date 
Speaker  Topic 
Thursday, 08 October 
Dariusz Dereniowski, Gdansk University of Technology  Nonclassical measures for evaluating search strategies 
Thursday, 15 October 
Daniel Horsley, Memorial University of Newfoundland 
Embedding partial Steiner triple systems 
Thursday, 22 October 
Asiyeh Sanaei, Memorial University of Newfoundland 
Rectilinear Symmetric Crossing Number of Complete Graphs 
Thursday, 05 November 
J.C. LoredoOsti, Memorial University of Newfoundland 
Trees of descent, Steiner trees and the computation of likelihood in complex genealogies 
Thursday, 03 December 
Andrew Jesso, Memorial University of Newfoundland 
The Hamiltonicity of BlockIntersection Graphs of Balanced Incomplete Block Designs 
Friday, 11 December 
Rebecca Keeping, Memorial University of Newfoundland  The Watchman's Walk Problem and its Variations 


Date 
Speaker  Topic 
Friday, 31 July 
Adrian Vetta, McGill University  Paths, viruses, and galaxy cutsets 


Date 
Speaker  Topic 
Friday, February 13th 
Oznur Yasar Diner, Memorial University of Newfoundland  Forbidden Minor Constructions for 4Searchable SeriesParallel Graphs 
Friday, February 20th 
David Pike, Memorial University of Newfoundland  Phylogenetic Networks for Human mtDNA Haplogroup T 
Friday, February 27th 
Danny Dyer, Memorial University of Newfoundland  Cyclic perfect $T(P_2 cup P_2 cup P_2)$ triple systems 
Friday, March 13th 
Nabil Shalaby, Memorial University of Newfoundland  SkolemLangford Type Sequences 
Friday, March 20th 
Ahmed Ababheh, Memorial University of Newfoundland  Disjoint starter sequences 
Tuesday, April 28th 
Rebecca Keeping, Memorial University of Newfoundland  The Watchman's Walk Problem with Time Restraints 


Date 
Speaker  Topic 
Thursday, 
Dominique de Werra, École Polytechnique Fédérale de Lausanne 
Graph transformations and peseudoboolean reduction 
Thursday, 
David Pike, Memorial University of Newfoundland 
Hamiltonicity and Restricted BlockIntersection Graphs of tDesigns 
Thursday, 
Dariusz Dereniowski, Gdansk University of Technology 
Using edge rankings for searching in partial orders 
Thursday, 
Daniel Horsley, Memorial University of Newfoundland 
A solution to Alspach's problem for complete graphs of large odd order 
Thursday, 
Edgar Goodaire, Memorial University of Newfoundland 
Groupbased Latin Squares 
Thursday, 
Rebecca Keeping, Memorial University of Newfoundland 
Maximum kLimited Packings in Trees 
Thursday, 
Danny Dyer, Memorial University of Newfoundland 
Two coloured path decompositions 
Tuesday, 
Rebecca Keeping, Memorial University of Newfoundland 
A Review of the Watchman's Walk Problem 


Date 
Speaker  Topic 
Wednesday, 
Vaclav Linek, University of Winnipeg 
Octahedral Designs 
Tuesday, 
Nancy Clarke, Acadia University 
Variations of the Cops and Robber Game Played with Imperfect Information 
Wednesday, 
Boting Yang, University of Regina 
Edge Searching on CycleDisjoint Graphs 
Wednesday, 
Pawel Pralat, Dalhousie University 
Cleaning dregular graphs with brushes 


Date  Speaker  Topic 
Wednesday, Feb 13th 
Daniela Silvesan, Memorial University 
The spectrum of Skolem and hooked Skolem sequences with prescribed pairs in common 
Friday, Feb 29th 
Oznur Yasar Memorial University 
Fast Search is Linear for Trees 
Wednesday, May 7th 
Laura ChavezLomeli, Simon Fraser University 
Chromatic and flow number for matroids 


Date  Speaker  Topic 
Friday, Jan 26th 
Vaclav Linek, University of Winnipeg 
Langford sequences: parametrizations, commutative diagrams and quotients 


Date  Speaker  Topic 
Tuesday, Oct 31st 
Josh Manzer Memorial University 
Skolem labeling of generalized windmill graphs 


Date  Speaker  Topic 
Thursday, May 11 
Brian Alspach, University of Regina 
Groups acting on graphs 
Thursday, Jun 15 
Gary MacGillivray, University of Victoria 
Circular colourings of hypergraphs 
Tuesday, Aug 8 (Japan) 
Shinya Fujita, Gunma National College of Technology 
Recent results on vertexdisjoint cycles in graphs 
Tuesday, Aug 15 
Shinya Fujita, Gunma National College of Technology (Japan) 
Nonseparating subgraphs in highly connected graphs 


Date  Speaker  Topic 
Thursday, Feb 16 
SuengByond (Light) Go, Memorial University 
Cyclic Steiner triple systems with cyclic subsystems 
Thursday, Mar 2 
Yubo Zou, Memorial University 
Dominating hypercubes 
Thursday, Apr 6 
Brenda Wicks, Memorial University 
Graceful labelings of triangular cacti graphs 
Thursday, Apr 20 
Oznur Yasar, Memorial University 
Edge searching weighted graphs 


Date  Speaker  Topic 
Friday, Nov 18 
Colin Reid, Memorial University 
Nearlambdafold Skolem sequences and infinite Skolem sequences 
Friday, Nov 25 
Yubo Zou, Memorial University Decycling 
Fibonacci cubes 


Date  Speaker  Topic 
Thursday, Jun 30 
Danny Dyer, University of Regina 
Isomorphic factorizations of circulant graphs 


Date  Speaker  Topic 
Friday, Feb 25 
Oliver Ittig, Swiss Federal Institute of Technology 
Scheduling with multiprocessors: A rounding network algorithm with a constant error 


Date  Speaker  Topic 
Tuesday, Nov 2 
Nabil Shalaby, Memorial University 
Skolemtype rectangles 
Tuesday, Nov 9 
Yubo Zou, Memorial University 
Decycling of Cartesian product of cycles 
Tuesday, Nov 16 
David Morgan, University of Alberta 
Useful vertex names: Informative labelling schemes for graphs 
Tuesday, Nov 23 
Andrea Burgess, Memorial University 
Invariants for even cycle systems 
Tuesday, Nov 30 
Colin Reid, Memorial University 
The existence of looped mnearSkolem sequences 


Date  Speaker  Topic 
Friday, Jun 18 
Danny Dyer, Simon Fraser University 
Using cliques to sweep graphs 


Date  Speaker  Topic 
Thursday, Oct 16 
Eddie Cheng, Oakland University 
An introduction to linear integer programming via the stable set problem 


Date  Speaker  Topic 
Wednesday, Jul 2 
Danny Dyer, Simon Fraser University 
Twocoloured path decompositions 


Date  Speaker  Topic 
Tuesday, Feb 4 
Rolf Rees, Memorial University 
Constructing Steiner triple systems for all admissible orders  Part I 
Tuesday, Feb 18 
Rolf Rees, Memorial University 
Constructing Steiner triple systems for all admissible orders  Part II 
Tuesday, Mar 25 
Nabil Shalaby, Memorial University 
Skolemtype sequences 
Tuesday, Apr 1 
Rolf Rees, Memorial University 
Constructing Steiner triple systems for all admissible orders  Part III 


Date  Speaker  Topic 
Friday, Aug 9 
Martin Grüttmüller, University of Rostock (Germany) 
Completing partial Latin squares with prescribed diagonals 
Wednesday, Aug 14 
Gennian Ge, Suzhou University (P.R. China) 
Whist tournaments 


Date  Speaker  Topic 
Wednesday, Jan 30 
Eric Moorhouse, University of Wyoming 
Projective planes  Part I 
Wednesday, Feb 6 
Eric Moorhouse, University of Wyoming 
Projective planes  Part II 
Wednesday, Feb 20 
Nabil Shalaby, Memorial University Disjoint 
Skolem sequences 
Wednesday, Mar 6 
Rolf Rees, Memorial University 
Embedding cyclic partial Steiner triple systems 
Wednesday, Mar 27 
Patrick Fleming, University of Wyoming 
Generating functions 
Wednesday, Apr 3 
Alasdair Graham, Memorial University 
A survey of packings and coverings of simple graphs 
Wednesday, Apr 3 
Aygul Mamut, Memorial University and Xinjiang University 
Decompositions of graphs into 1factors 
Thursday, Apr 4 
Chao Zhong, Memorial University 
Perfect graphs 


Date  Speaker  Topic 
Monday, Sep 10 
Sarah Mathews, Memorial University 
Configurations in Steiner triple systems 
Wednesday, Sep 19 
Rolf Rees, Memorial University 
On holes in tdesigns  Part I 
Thursday, Sep 27 
Vaclav Linek, University of Winnipeg 
Pattern avoidance: The Abelian case 
Wednesday, Oct 3 
Rolf Rees, Memorial University 
On holes in tdesigns  Part II 
Wednesday, Oct 17 
Alasdair Graham, Memorial University 
Skolem labelled graphs 
Wednesday, Oct 31 
Eric Moorhouse, University of Wyoming 
The transfer matrix method 
Wednesday, Nov 21 
Eddie Cheng, Oakland University 
Submodular functions, polymatroids and strength 
Friday, Nov 30 
Joanna EllisMonaghan, University of Vermont 
An introduction to the Tutte polynomial 


Date  Speaker  Topic 
Tuesday, Feb 6 
Nabil Shalaby, Memorial University 
Skolem labelled graphs 
Tuesday, Feb 13 
Michael Parmenter, Memorial University 
Applications of graph theory to the study of DNA and RNA chains (1) 
Tuesday, Feb 20 
Michael Parmenter, Memorial University 
Applications of graph theory to the study of DNA and RNA chains (2) 
Tuesday, Mar 13 
Rolf Rees, Memorial University 
A survey of Kirkman designs (2) 
Tuesday, Mar 20 
David Morgan, Memorial University 
Domination in graphs (1) 
Tuesday, Mar 27 
A.E. Fekete, Memorial University 
Spectral sequences of integers 
Tuesday, Apr 10 
David Pike, Memorial University 
A cryptographic application of graph theory 
Tuesday, Apr 17 
David Morgan, Memorial University 
Domination in graphs (2) 
Tuesday, Apr 24 
David Morgan, Memorial University 
Gracefully labelled trees from Skolem and related sequences 
Wednesday, Apr 25 
Alex Rosa, McMaster University 
Large sets of Steiner triple systems 


Date  Speaker  Topic 
Tuesday, Sep 19 
Eugene Lilly, Memorial University 
Mutually orthogonal Latin squares 
Tuesday, Sep 26 
Sarah Mathews, Memorial University 
Cyclically indecomposable twofold triple systems from Skolem sequences 
Tuesday, Oct 3 
Robin Swain, Memorial University 
8cycle decompositions of the Cartesian product of two complete graphs 
Tuesday, Oct 10 
Vesselin Dresnky, Bulgarian Academy of Sciences 
Applications of the pigeon hole principle 
Tuesday, Oct 17 
Rolf Rees, Memorial University 
A survey of Kirkman designs (1) 
Tuesday, Oct 24 
David Morgan, Memorial University 
A survey of graceful labelings 


Date  Speaker  Topic 
Thursday, Feb 17 
Michael Parmenter, Memorial University 
On groups with redundancy in multiplication 
Thursday, Mar 2 
Rolf Rees, Memorial University 
Magic labelings of graphs 


Date  Speaker  Topic 
Thursday, Nov 4 
Nabil Shalaby, Memorial University 
Optimal complementary coverings of the complete graphs by paths of length three 
Thursday, Nov 23 
Yuri Bahturin, Memorial University, and Victor Petrogradsky, Ul'yanovsk State University (Russia) 
Young diagrams, generating functions and proper identities II 
Thursday, Dec 2 
David Morgan, Memorial University 
Applications of Polya's counting theorem in chemical compounds 


Date  Speaker  Topic 
Thursday, Jan 26 
Nabil Shalaby, Memorial University 
Skolem sequences and applications  I 
Tuesday, Feb 2 
Nabil Shalaby, Memorial University 
Skolem sequences and applications  II 
Tuesday, Feb 9 
David Pike, Memorial University 
Perfect 1factorisations  I 
Tuesday, Feb 16 
David Pike, Memorial University 
Perfect 1factorisations  II 
Tuesday, Mar 2 
David Morgan, Memorial University 
Graceful labelings of graphs  II 


Date  Speaker  Topic 
Tuesday, Sep 29 
Tara Stuckless, Memorial University 
The existence of looped Langford sequences 
Tuesday, Oct 6 
David Pike, Memorial University 
Decomposing blockintersection graphs of Steiner triple systems into triangles  I 
Tuesday, Oct 20 
David Pike, Memorial University 
Decomposing blockintersection graphs of Steiner triple systems into triangles  II 
Tuesday, Oct 27 
Antal Fekete, Memorial University 
Stepnumbers and their applications  I 
Tuesday, Nov 3 
Antal Fekete, Memorial University 
Stepnumbers and their applications  II 
Tuesday, Nov 10 
Antal Fekete, Memorial University 
Stepnumbers and their applications  III 
Tuesday, Nov 17 
Antal Fekete, Memorial University 
Stepnumbers and their applications  IV 
Tuesday, Nov 24 
David Morgan, Memorial University 
Graceful labelings of graphs  I 