The Combinatorics Group: Seminars

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.


Fall 2012

 
Date Speaker Topic

Friday, 2 November

Gena Hahn, Universite de Montreal Cops and robbers on graphs - finite and infinite

 
Summer 2012

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


Winter 2012

 
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


Winter 2011

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


Summer 2010

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


Winter 2010

 

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


Fall 2009

 

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. Loredo-Osti,
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 Block-Intersection Graphs of Balanced Incomplete Block Designs

Friday, 11 December

Rebecca Keeping, Memorial University of Newfoundland The Watchman's Walk Problem and its Variations


Summer 2009

 

Date

Speaker Topic

Friday, 31 July

Adrian Vetta, McGill University Paths, viruses, and galaxy cutsets


Winter 2009

 

Date

Speaker Topic

Friday, February 13th

Oznur Yasar Diner, Memorial University of Newfoundland Forbidden Minor Constructions for 4-Searchable Series-Parallel 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 Skolem-Langford 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


Fall 2008

 

Date

Speaker Topic

Thursday,
September 11th

Dominique de Werra,
École Polytechnique Fédérale de Lausanne
Graph transformations and peseudoboolean reduction

Thursday,
September 18th

David Pike,
Memorial University of Newfoundland
Hamiltonicity and Restricted Block-Intersection Graphs of t-Designs

Thursday,
September 25th

Dariusz Dereniowski,
Gdansk University of Technology
Using edge rankings for searching in partial orders

Thursday,
October 2nd

Daniel Horsley,
Memorial University of Newfoundland
A solution to Alspach's problem for complete graphs of large odd order

Thursday,
October 9th

Edgar Goodaire,
Memorial University of Newfoundland
Group-based Latin Squares

Thursday,
October 16th

Rebecca Keeping,
Memorial University of Newfoundland
Maximum k-Limited Packings in Trees

Thursday,
October 23rd

Danny Dyer,
Memorial University of Newfoundland
Two coloured path decompositions

Tuesday,
October 28rd

Rebecca Keeping,
Memorial University of Newfoundland
A Review of the Watchman's Walk Problem


Summer 2008

 

Date

Speaker Topic

Wednesday,
July 9th

Vaclav Linek,
University of Winnipeg
Octahedral Designs

Tuesday,
August 19th

Nancy Clarke,
Acadia University
Variations of the Cops and Robber Game Played with Imperfect Information

Wednesday,
August 20th

Boting Yang,
University of Regina
Edge Searching on Cycle-Disjoint Graphs

Wednesday,
August 20th

Pawel Pralat,
Dalhousie University
Cleaning d-regular graphs with brushes


Winter 2008

 
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 Chavez-Lomeli,
Simon Fraser University
Chromatic and flow number for matroids


Winter 2007

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


Fall 2006

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


Spring 2006

 
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 vertex-disjoint cycles in graphs
Tuesday,
Aug 15
Shinya Fujita,
Gunma National College of Technology (Japan)
Non-separating subgraphs in highly connected graphs


Winter 2006

 
Date Speaker Topic
Thursday,
Feb 16
Sueng-Byond (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


Fall 2005

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


Spring 2005

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


Winter 2005

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


Fall 2004

 
Date Speaker Topic
Tuesday,
Nov 2
Nabil Shalaby,
Memorial University
Skolem-type 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 m-near-Skolem sequences


Spring 2004

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


Fall 2003

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


Spring 2003

 
Date Speaker Topic
Wednesday,
Jul 2
Danny Dyer,
Simon Fraser University
Two-coloured path decompositions


Winter 2003

 
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
Skolem-type sequences
Tuesday,
Apr 1
Rolf Rees,
Memorial University
Constructing Steiner triple systems for all admissible orders - Part III


Spring 2002

 
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


Winter 2002

 
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 1-factors
Thursday,
Apr 4
Chao Zhong,
Memorial University
Perfect graphs


Fall 2001

 
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 t-designs - 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 t-designs - 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 Ellis-Monaghan,
University of Vermont
An introduction to the Tutte polynomial


Winter 2001

 
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


Fall 2000

 
Date Speaker Topic
Tuesday,
Sep 19
Eugene Lilly,
Memorial University
Mutually orthogonal Latin squares
Tuesday,
Sep 26
Sarah Mathews,
Memorial University
Cyclically indecomposable two-fold triple systems from Skolem sequences
Tuesday,
Oct 3
Robin Swain,
Memorial University
8-cycle 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


Winter 2000

 
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


Fall 1999

 
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


Winter 1999

 
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 1-factorisations - I
Tuesday,
Feb 16
David Pike,
Memorial University
Perfect 1-factorisations - II
Tuesday,
Mar 2 
David Morgan,
Memorial University
Graceful labelings of graphs - II


Fall 1998

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