Weekly SFU Discrete Math Seminars
Tuesdays 1:302:30PM in SCK 9509
Please join us for this weekly seminar on a wide variety of topics under the umbrella of discrete mathematics. We are pleased to offer cookies, coffee and tea. We gratefully acknowledge the Pacific Institute of Mathematical Sciences for their generous funding since 2010.
Unless otherwise noted, all talks take place on Tuesdays at 1:30pm in K9509. We welcome remote participation from groups at other universities; for details on how to arrange this, see our Remote Participation page.
All talks will be announced on this page, on the department calendar, and on the DM Seminar mailing list. If you have an SFU email address, you can subscribe or unsubscribe to the mailing list by logging in to maillist.sfu.ca and searching for the mathdmsem list. Otherwise, you can ask any discrete math faculty member to manually add you to the list.
Current organizer: Marni Mishna
Fall 2017
Date  Speaker, Affiliation  Talk Title 

24 Oct  Ross McConnell Colorado State 
Outerplanar and Planar Graphs 
17 Oct  Ron Aharoni Israel Institute of Technology 
Cooperative colorings 
10 Oct  Sheila Sundaram Pierrepont School 
Variations on the S_nmodule Lie_n: results and conjecture 
3 Oct  Amanda Montejano Universidad Nacional Autónoma de México 
Zerosum over Z 
26 Sept  Jehanne Dousse Universität Zürich 
Refinement of partition identities 
19 Sept  Moshe Rosenfeld U of Washington 
Starters what you know or don't care to know: old and new open problems 
12 Sept  Amelie Trotignon SFU 
Simple Walks in the Three Quarter Plane 
Summer 2017
Date  Speaker, Affiliation  Talk Title 

29 Aug  David Wood Monash University 
Monotone expanders and applications 
08 Aug  Aniket Mane SFU 
A tractable variant of the Single Cut or Join distance with duplicated genes 
08 Aug 
Abhinav Shantanam SFU 
Hadwiger Number of Complements of Kneser Graphs with \alpha = 2 
01 Aug  Dirk Nowotka Kiel University 
kabelian pattern matching 
25 July  Cesar Hernandez Cruz Universidad National Automate de Mexico 
kquasitransitive digraphs of large diameter 
25 July  Samuel Simon SFU 
Linking Systems of Difference Sets 
18 July  Shuxing Li Zhejiang University/SFU 
Construction and nonexistence of strong external difference family 
11 July  Julian Sahasrabudhe U of Cambridge 
Exponential Patterns in Arithmetic Ramsey Theory 
04 July  Avi Kulkarni SFU 
Reading graphs into SAGE from an IPE diagram 
04 July  Sebastian Gonzalez Hermosillo de la Maza SFU 
Proper Orientations of Planar Bipartite Graphs 
06 Jun 
Arnaud Casteigts, LaBRI, U de Bordeaux 
Robustness in Highly Dynamic Networks 
30 May  Joao Meidanis, U of Campinas, Brazil 
Genome Matrices and the Median Problem 
23 May 
Stephen Melczer, U of Waterloo 
Effective Analytic Combinatorics in Several Variables 
16 May  Mark Kayll, U of Montana 
Derangements through the years: 170819962014 
Spring 2017
Date  Speaker, Affiliation  Talk Title 

18 April  Julian Sahasrabudhe, U of Cambridge 
Exponential Patterns in Arithmetic Ramsey Theory 
28 Mar  Jonathan Jedwab, SFU 
Costas cubes 
21 Mar 
Pavol Hell, SFU 
Obstruction Certificates for Geometrically Defined Graph (and Digraph) Classes 
14 Mar  David Rowe, Universitat Mainz 
*This Talk Will Begin At 2pm* The Role of Configurations in Classical Algebraic Geometry 
7 Mar  Peter Wu, SFU 
On maximal size of 2weakly compatible split system 
28 Feb  Sean Griffin, U of Washington 
Schur positivity and labeled binary trees 
21 Feb  Bojan Mohar, SFU 
The Crossing Number of the Cone of the Graph 
7 Feb  Fiachra Knox, SFU 
Majority Colourings of Digraphs 
31 Jan  Luis Goddyn, SFU 
Parity Trackles on Surfaces and Perturbations of Bilinear Forms 
24 Jan  Jernej Azarija, SFU 
On a classification of some small strongly regular graphs 
2016 Talks
Fall 2016
Date  Speaker, Affiliation  Talk Title 

20 Sep  Tony Huynh, U Libre de Bruxelles 
The matroid secretary problem for minorclosed classes and random matroids 
18 Oct  Marni Mishna, SFU 
Universality classes for weighted lattice paths: where probability and ACSV meet 
25 Oct  Jørgen BangJensen, U of Southern Denmark 
Connectivity properties of tournaments and semicomplete digraphs 
1 Nov  Seyyed Aliasghar Hosseini, SFU 
Cops and Robbers on Oriented Grids I 
8 Nov  Sebastian Gonzalez, SFU  Cops and Robbers on Oriented Grids II 
15 Nov  Samantha Dahlberg, UBC  Pattern Avoidance in Restricted Growth Functions 
22 Nov  Steffen Borgwardt, U of Colorado  The Hirsch Conjecture is true for NetworkFlow Polytopes 
29 Nov  Justin Chan, SFU  Suitable Cores And Arrays 
*Please Note Date/Location: Talk on December 5th will be held in the IRMACS Theatre on MONDAY, Dec 5th 

5 Dec  Fan Chung Graham, U of California, San Diego 
Sequences: random, structured or something in between? 
Summer 2016
10 May  Natalia GarcíaColín U Nacional Autónoma de México 
On the tolerated Tverberg number 
17 May  Jonathan Jedwab Simon Fraser University 
How many mutually unbiased bases can exist in complex space of dimension d? 
24 May  Dmitry Doryn IBS Center for Geometry and Physics 
c_{2} invariants of Feynman graphs 
31 May  —  CANCELLED 
7 Jun  —  CANCELLED 
14 Jun  César Hernández Cruz U Autónoma de Zacatecas 
A dichotomy for the kernel by Hwalks problem in digraphs 
21 Jun  Flavia Bonomo U Buenos Aires 
Threecoloring and list threecoloring graphs without induced paths on seven vertices 
28 Jun (extra) 11:30am 
Ross McConnell Colorado State University 
Algorithms on graphs arising from intersections of intervals 
28 Jun  Melissa Huggan Dalhousie University 
Conjoined games: gocut and snogo 
5 Jul (extra) 11:30am 
Mathew Francis Indian Statistical Institute, Chennai Centre 
Uniquely restricted matchings in interval graphs 
5 Jul  Hendrik Süß University of Manchester 
Frobenius splitting of toric and Tvarieties 
12 Jul  Bruce Reed McGill University 
How to determine if a random graph with a fixed degree sequence has a giant component 
19 Jul  —  CANCELLED 
26 Jul  Iain Crump Simon Fraser University 
The extended graph permanent as an affine variety 
Thursday 28 Jul 3:30pm 
Mordecai Golin Hong Kong UST 
Optimal binary comparison search trees 
Spring 2016
12 Jan  Rodolphe Garbit Université d'Angers 
On the exit time from a cone for random walks with drift 
19 Jan  Suil O Simon Fraser 
Interlacing families and their application to digraphs 
26 Jan IRMACS Theatre 1:00pm (12:00 reception) 
Kilian Raschel CNRS / U François Rabelais  Tours 
Counting quadrant walks via Tutte's invariants and transformation theory of elliptic functions 
2 Feb  Stefan Hannie Simon Fraser 
Immersion of 2regular digraphs 
9 Feb  Reading break  CANCELLED 
16 Feb  Pierre Tarrago Saarlandes University 
Categories of twocolored noncrossing partitions 
23 Feb  —  CANCELLED 
1 Mar  Cedric Chauve Simon Fraser 
Counting, generating and sampling tree alignments 
8 Mar  Julien Courtiel UBC 
Terminal chords in connected diagrams chords 
15 Mar  Claudia Linhares Sales UF Ceará 
Bcontinuity of lexicographic product of graphs 
22 Mar  Alejandro Morales UCLA 
Hook Formulas for Skew Shapes 
22 Mar (2nd talk) 3:00pm 
Barnaby Martin Middlesex University London 
The packing chromatic number of the infinite square lattice 
29 Mar  Fiachra Knox Simon Fraser 
Ramanujan gap for the norm of adjacency operators 
5 Apr    PIMSSFU Colloquium: Anthony VárillyAlvarado in IRMACS Theatre 
2015 Talks
Fall 2015
22 Sept  Ilya Shmulevich Institute for Systems Biology 
Probabilistic Boolean Networks as Models of Genetic Regulatory Networks 
Thursday 24 Sept 11:00am 
Harrison Chapman University of Georgia 
Asymptotic laws for knot diagrams 
29 Sept  Gary Greaves Tohoku University 
Equiangular lines in Euclidean spaces 
6 Oct  Karen Yeats Simon Fraser 
A few c_2 invariants of circulant graphs 
13 Oct  Abbas Mehrabian UBC/SFU 
Cops and a Fast Robber on Planar and Random Graphs 
20 Oct  Matt DeVos Simon Fraser 
Flows with large support 
27 Oct  Alejandro Erickson Durham University 
Graphs at the heart of the cloud 
3 Nov  Eric Fusy CNRS / École Polytechnique 
Baxter permutations and meanders 
10 Nov  Yota Otachi Japan Advanced Institute of Science and Technology 
Induced minorfree graphs: isomorphism and cliquewidth 
17 Nov  Theodore Kolokolnikov Dalhousie University 
Maximizing algebraic connectivity for certain families of graphs 
24 Nov  Shenwei Huang Simon Fraser University 
Colouring graphs without an induced path: A survey 
1 Dec  Luis Goddyn Simon Fraser 
Extending Hawiger’s Conjecture and Bicircular Matroids 
8 Dec  Campus closure  CANCELLED 
Monday 14 Dec PIMS 8500 1:30pm 
Chính Hoàng Wilfred Laurier University 
On the structure of (pan, even hole)free graphs 
Monday 14 Dec PIMS 8500 3:00pm 
Mark Giesbrecht U Waterloo 
Eigenvalues, invariant factors and random integer matrices (with a little bit of computing) 
Summer 2015
12 May 
Nicholas Beaton U. Saskatchewan 
Solvable selfavoiding walk and polygon models with large growth rates 
19 May  Matt DeVos Simon Fraser 
On nowherezero flows 
26 May  Luis Goddyn Simon Fraser 
Odd thrackles on surfaces 
02 June  CanaDAM 2015  CANCELLED 
09 June  Robert Samal Charles U. 
Unique Vector Coloring and Cores 
16 June  Ron Graham conference  CANCELLED 
23 June  Amanda Montejano UNAM 
Cyclic orders and oriented 3hypergraphs. 
30 June  Marni Mishna Simon Fraser 
Efficient uniform generation of reluctant walks 
07 July  Moshe Rosenfeld  The wondering salmon problem and (unrelated) graph designs 
14 July  Christopher Duffy UVic 
Colourings and simple colourings of (j,k)mixed graphs 
Thursday 23 July 
Bruce Reed McGill University 
Connectivity preserving iterative compaction 
28 July  César HernándezCruz UNAM 
Mixed cages Acyclic disconnection and minimum feedback arc sets of graphs 
04 August  Jan Manuch UBC 
Spring 2015
Tuesday Jan 13 
David Gajser, University of Ljubljana, Slovenia  Simple PTAS’s for families of graphs excluding a minor 
Tuesday Jan 20 
Martina Mockovciakova (University of West Bohemia, Pilsen, Czech Republic)  Star Edge Coloring of Some Classes of Graphs 
Tuesday Jan 27 (IRMACS, 12:30 reception) 
Michael Singer (NCSU) (PIMS Distinguished Visitor) 
Galois theory of difference and differential equations. 
Tuesday Feb 3 
Manuel Kauers (RISC) 
Walks in the Quarter Plane with Multiple Steps 
Tuesday Feb 10 
(Reading Week) 

Tuesday Feb 17 
Cedric Chauve, SFU  Graphtheoretical algorithms to correct gene trees 
Tuesday Feb 24 
Edita Rollova (KMA)  Homomorphisms and colourings of signed graphs 
Tuesday Mar 3 
Murilo da Silva  Evenholefree graphs 
Tuesday Mar 10 
Henry Liu, New University Lisbon, Portugal  Connected subgraphs in edgecoloured graphs 
Tuesday Mar 17 
Ashok Rajaraman  Vertex Ordering Problems for Hypergraphs: Connections to the Consecutive Ones Property 
Tuesday Mar 24 
Veronika Irvine (U Victoria)  Lace patterns 
Tuesday Mar 31 
Guillaume Chapuy (Liafa/ Paris 7)  Spanning trees of the graph of spanning trees. 
Tuesday April 7  Karen Yeats (SFU)  Rooted tree classes and the renormalization group equation 
Tuesday April 14  Nathan Ilten (SFU)  Counting lines on toric surfaces 
2014 Talks
Fall 2014
Tuesday Sept 16 
Scott Garrabrant, UCLA 
Counting with Irrational Tiles 
Tuesday Sept 23 
Daryl Funk (SFU) 
Biased graphs, group labelled graphs, and wellquasiordering 
Tuesday Sept 30 
Jonathan Jedwab SFU  The structure of Costas arrays 
Tuesday Oct 7 
Eric Fusy (CNRS/Polytechnique)  Bijections on Schnyder woods 
Tuesday Oct 14 
Anna Galluccio ( IASICNR (Italy)) 
Minimally nonbalanced diamondfree graphs 
Tuesday Oct 21 
Karen Yeats (SFU)  Tree Feynman rules 
Tuesday Oct 28 
Thomas Mattman (California State/Chico)  There are too many knotted graphs! 
Tuesday Nov 4 
Julien Courtiel (SFU/PIMS)  Planar maps and spanning forests 
Tuesday Nov 11 
No Seminar (Remembrance day)  
Tuesday Nov 18 
Markus Hihn (Humboldt University, Berlin) 
Decorated chord diagrams and DysonSchwinger equations 
Tuesday Nov 25, 2:30  3:20 
Bala Krishnamoorthy (Washington State)  Flat Norm Decomposition of Integral Currents 
Tuesday Dec 2 (2:30 1:30 IRMACS THEATRE) 
Ross Churchley, Tara Petrie, Stefan Hannie, Stefan Trandafir, Ashok Rajaraman, Laura Guiterrez Funderburk 
Rapid Fire Discrete Mathematics 
Summer 2014
Tuesday May 20 
Tom Boothby (SFU)  Existence of Heffter Arrays 
Tuesday May 27 
Aiden A. Bruen, Carleton University 
Perspective sets and blocking sets 
Tuesday June 3 
Luis Goddyn (SFU)  Open Problems in Hypergraph coverings 
Tuesday June 10  Yann Ponty (Polytechnique/CNRS)  Treedecomposition and sequence/structure alignment of RNA structures 
Tuesday June 17  Luis Goddyn (SFU)  
Tuesday June 24  Bradley Jones (SFU)  Hook length formulae, Butcher series and tree factorials 
Tuesday July 8  Mike Hoffman (US Naval Academy) 
Multiple zeta values and algebraic combinatorics 
Tuesday July 15  Cancelled  
Tuesday July 22  Cesar Cruz  The strong convexity spectra of grids / Split digraphs 
Tuesday July 29  Ebad Mahmoodian (Sharif University of Technology, Iran) 
From defining sets in graph coloring to Sudoku puzzles 
Spring 2014
Friday January 10, 10 AM  Olivier Bodini (LIPN/ Paris 13)  Three ways to generate at random a binary tree 
Tuesday Jan 21 
Marni Mishna (SFU) 
Diagonals and Dfiniteness 
Tuesday Jan 28 
Iain Crump (SFU)  Forbidden minors for graphs with no first obstruction to parametric Feynman integration 
Tuesday February 4 
Saeed Rezaei (SFU)  Entropy and Graphs 
Tuesday February 11 
Martin Skutella (TU Berlin)  In defense of the simplex algorithm's worstcase behavior 
Tuesday February 18 
Amy Wiebe (SFU)  Constructions of complex equiangular lines 
Tuesday February 25 
Steve Butler (Iowa State University)  Hypercube orientations with degree restrictions 
Tuesday March 4 TASC 1: 9204 
Jarik Nesetril (Charles University)  Ramsey Classes  Old and New 
Tuesday March 11 
Veselin Jungic (SFU)  Sometimes it is easier to see than to say: A few classical theorems in Ramsey theory. 
Tuesday March 18 
Hehui We (SFU)  Dicromatic number and fractional chromatic number 
Tuesday March 25 
Justin Chan (SFU)  An infinite family of invWilfequivalent permutation pairs 
Tuesday April 1 
Lerna Pehlivan (Washington)  Random 312Avoiding Permutations 
Tuesday April 8 
Huang Huo (IAS) 
The minimum number of nonnegative edges in hypergraphs 
Tuesday April 15 
Matej Stehlik (Grenoble) 
Colouring quadrangulations of projective spaces 
Tues/Wed April 15  16 TASC II 8500 
PIMS Analytic RNA Combinatorics  (Introductory talk Monday 1:30  3PM 
Tuesday April 22 
David Bryant (Otago)  The Geometry of Hypergraphs 
2013 Talks
Fall 2013
Tues Sept 10 / 2:30 / K9509 
Karen Yeats (SFU)  Factorizations of Feynman graph denominators 
Tues Sept 17 / 2:30 / K9509 
Petr Lisonek (SFU) 
On KochenSpecker sets 
Tues Sept 24 / 2:30 / K9509 
Ka Hin Leung (National U, Singapore) 
Unique Sums and Differences in Finite Abelian Groups 
Tues Oct 1 / 2:30 / K9509  Yvan le Borgne  On computing Baker and Norine's rank parameter on complete graphs. 
Tues Oct 15 / 2:30 / K9509 
Dan Archdeacon (U Vermont)  Embedding complete graphs with every triangle a face. 
Tues Oct 22 / 2:30 / K9509 
Krystal Guo (SFU)  Simple eigenvalues of vertextransitive graphs 
Tues Oct 29 / 2:30 / K9509  Jérémie Lumbroso (SFU) 
Elegantly taming data streams with randomness 
Tues Nov 12 / 2:30 / K9509  Tamon Stephen (SFU)  Lower Bounds for Colourful Simplicial Depth 
Tues Nov 19/ 2:30 / K9509  Ameera Chowdhury  A Proof of the ManickamMiklo ́sSinghi Conjecture for Vector Spaces 
Tues Nov 26/ 2:30 / K9509  Arash Rafieh  
Tues Dec 3 / 2:30 /IRMACS  Cedric Chauve  Comparative assembly of the Black Death agent genome 
Tues Dec 10/ 2:30 / K9509  Jernej Rus  Stable traces 
Summer 2013
Thurs May 2 / 11:00 / K9509  Bernard Lidicky (Illinois)  Planar 4critical graphs with four triangles 
Tues May 14 / 2:30 / K9509  Shonda Gosselin (Winnipeg)  Algebraic hypergraph decompositions 
Tues May 21 / 2:30 / K9509  Steve Melczer (SFU)  Classifying Lattice Walks in the Quarter Plane 
Tues May 28 / 2:30 / K9509  Andrew Poelstra  RamseyScript and Double Arithmetic Progressions 
Thurs June 6 / 2:30 / K9509  Brian Alspach (Newcastle)  The Coxeter Group Project: A Progress Report 
Tues June 18 / 2:30 / K9509  Robert Samal (Charles U) 
Hedetniemi conjecture for strict vector chromatic number 
Tues June 25 / 2:30 / K9509  Jessica McDonald  Packing Steiner Trees 
Tues July 23 / 2:30 /TASC2 8500 Joint with computer algebra seminar 
Manuel Kauers (Johannes Kepler U) 
Finding Closed Form Solutions of Differential Equations 
Tues Aug 6 / 2:30 / TASC2 8500  Ales Drapal (Charles U) 
Dissections of equilateral triangles and their embeddings into finite abelian groups 
Spring 2013
Tues Jan 8 / 2:30 / K9509  Jon Noel (McGill) 
A Proof of a Conjecture of Ohba 
Tues Jan 15 / 2:30 / K9509  Graham Banero (SFU)  Additive Complexity of Infinite Words 
Tues Jan 22 / 2:30 / K9509  Aidan Roy (DWave)  Graph minor embeddings and quantum annealing 
Tues Jan 29 / 2:30 / K9509  Vijaykumar Singh (SFU/UBC)  Algebraic and Combinatorial Quantum Codes 
Tues Feb 5 / 2:30 / K9509  Tony Huynh (SFU)  Even Cycle Decompositions of Graphs with no oddK_4minor 
Tues Feb 19 / 2:30 / K9509  Karen Yeats (SFU)  The corolla polynomial of a 3regular graph 
Tues Feb 26 / 2:30 / K9509  Andrew King (SFU)  Circular backbone colouring 
Tues Mar 5 / 2:30 / K9509  Arash Rafiey (SFU)  Fixed Parameter Algorithms for Interval Vertex Deletion and Interval Completion Problems 
Tues Mar 12 / 2:30 / K9509  Matt DeVos (SFU)  Small Products in Groups 
Tues Mar 19 / 2:30 / K9509  Sam Johnson (SFU)  Towards a combinatorial understanding of lattice path asymptotics. 
Tues Mar 26 / 2:30 / K9509  Frederic Havet (SFU)  Disjoint union of directed cycles of length at least 3 
Tues Apr 2 / 2:30 / K9509  TJ Yusun (SFU)  Counting inequivalent monotone Boolean functions 
Tues Apr 9 / 2:30 / K9509  Justin Chan (SFU)  The ncard problem 
Tues Apr 16 / 2:30 / K9509  Daryl Funk (SFU)  Rearranging edge sets of cycles in graphs. 
2012 Talks
Fall 2012
Tues Sept 18 / 2:30 / K9509  Jason Bell (SFU) 
Diagonals of rational functions and differential equations 
Tues Sept 25 / 2:30 / K9509  Nicolas Marie (SFU)  Chord Diagrams Expansion and DysonSchwinger Equations 
Tues Oct 2 / 2:30 / K9509  Nick Harvey (UBC)  Graph Sparsifiers: A Survey 
Tues Oct 9 / 2:30 / K9509  Mohit Singh (McGill and Microsoft)  A Randomized Rounding Approach for Traveling Salesman Problem 
Tues Oct 16 / 2:30 / K9509  Frederic Havet  Finding a subdivision of a digraph 
Tues Oct 23 / 2:30 / K9509  Daniel Katz (SFU)  A New Record for Low Autocorrelation Sequences 
Tues Oct 30 / 2:30 / K9509  Katherine Edwards (Princeton) 
Edgecoloring 8regular planar graphs 
Tues Nov 6 / 2:30 / K9509  Jan Manuch  Selfassembly without cooperativity 
Tues Nov 13 / 2:30 / K9509  David Gunderson (Manitoba)  Random permutations and graceful paths 
Tues Nov 20 / 2:30 / K9509  Lily Yen (Capilano and SFU)  Crossings and Nestings for ArcColoured Permutations 
Tues Nov 27 / 2:30 / K9509  Bojan Mohar (SFU)  Median eigenvalues of graphs and HOMOLUMO separation 
Tues Dec 4 / 2:30 / K9509  Ryan Schwartz (UBC)  Unit distances with restricted angles 
Tues Dec 11 / 2:30 / K9509  Kenza Guenda (UVic) 
Automorphism Groups and Isomorphisms of Cyclic Combinatorial Objects 
Summer 2012
Tues May 15 / 2:30 / K9509  Bruce Sagan (Michigan State)  Permutation Patterns and Statistics 
Tues May 22 / 2:30 / K9509  Steve Chaplick (UofT)  BendBounded Path Intersection Graphs: Sausages, Noodles, and Waffles on a Grill 
Tues May 29 / 2:30 / K9509  Tamon Stephen (SFU)  The width of 4prismatoids 
Tues June 5 / 2:30 / K9509  Bruce Shepherd (McGill)  Maximum Throughput versus Minimum Congestion in Disjoint Path Problems in Planar Graphs 
Tues June 12 / 2:30 / K9509  Petr Škoda (SFU) and Sophie Burrill (SFU) 
SIAM preview: Petr Škoda  Obstructions of connectivity 2 for embedding graphs into the torus Sophie Burrill  Generating trees for partitions and permutations with no knestings 
Tues June 19 / 2:30 / K9509  Ryuhei Uehara (JAIST)  The Graph Isomorphism Problem on Geometric graphs 
Tues June 26 / 2:30 / K9509  Tony Huynh (KAIST)  Intertwining Connectivities in Matroids 
Tues July 10 / 2:30 / K9509  Matthew Folz (UBC)  Volume growth and the spectrum of infinite graphs 
Tues Aug 14 / 2:30 / K9509 Joint with CS seminar 
Luisa Gargano (Salerno) and Ugo Vaccaro (Salerno) 
Luisa Gagarno  Minimum Weight Dynamo and Fast Opinion Spreading Ugo Vaccaro  On the (in)approximability and exact algorithms for vector domination and related problems in graphs 
Spring 2012
Tues Jan 10 / 2:30 / K9509  James King (Oxford) 
Generating kFacets by Induction on the Dimension 
Tues Jan 17 / 2:30 / K9509  Roman Nedela (IMCS)  Decomposition of snarks along 6edgecuts 
Tues Jan 24 / 2:30 / K9509  Ladislav Stacho (SFU)  Minmax relations for odd cycles in planar graphs 
Tues Jan 31 / 2:30 / K9509  Arun Sharma (Berkeley)  Coloring with Crayons 
Wed Feb 1 / 3:30 / K9509 Joint with Computer algebra seminar  Christian Krattenthaler (Universität Wien)  A method for determining the mod2^k behaviour of (certain) recursive sequences 
Tues Feb 7 / 2:30 / K9509  Vlad Gheorghiu (Calgary) 
Optimal semiquantum secret sharing schemes 
Fri Feb 17 / 2:00 / K9509  Zdenek Dvorak (Charles University, Prague)  A sharper structure theorem for excluded topological minors 
Tues Feb 21 / 2:30 / K9509  Daniel Katz (SFU)  The Proof of Helleseth's Conjecture 
Tues Feb 28 / 2:30 / K9509  Juhani Karhumaki (University of Turku, Finland)  Independent systems and chains of solution sets of word equations 
Tues Mar 6 / 2:30 / K9509  Dennis Epple (UVic)  CANCELLED (rescheduled for Apr 17) 
Tues Mar 13 / 2:30 / K9509  Aaron Robertson (Colgate)  Thoughts on the 2Large Conjecture 
Tues Mar 20 / 2:30 / K9509  Ararat Harutyunyan (SFU)  Vertexarboricity of planar graphs 
Tues Mar 27 / 2:30 / K9509  Chris Mitchell (University of London)  Applying combinatorial group testing to trust evaluation in a distributed computing model 
Tues Apr 3 / 2:30 / K9509  Jane Wodlinger (SFU)  Wavelength Isolation Sequence Pairs: New Progress on an Abandoned Problem 
Tues Apr 10 / 2:30 / K9509  Cedric Chauve (SFU)  Certificates and spectral approach for the ConsecutiveOnes Property 
Tues Apr 17 / 2:30 / K9509  Dennis Epple (UVic)  The bichromatic number of graphs 
Tues Apr 24 / 2:30 / K9509  César HernandezCruz (SFU)  (k,l)kernels of digraphs 
2011 Talks
Fall 2011
Tues Sept 13 / 2:30 / K9509  Karen Yeats, SFU  Denominators and insertions 
Tues Sept 20 / 2:30 / K9509  Lino Demasi, SFU  Rooted Minors and Delta Wye Transformations 
Tues Sept 27 / 2:30 / K9509  Veselin Jungic, SFU  Chaotic orderings of the rationals and reals 
Tues Oct 4 / 2:30 / K9509  Luis Goddyn, SFU  TUM formulations for Hadwigger, Tutte and Wills 
Tues Oct 11/ 2:30 / K9509  Irene Pivotto, SFU 
Pairs of representations of signed binary matroids 
Thurs Oct 13 / 2:00 / K9509  Chris Godsil, U Waterloo  Quantum Problems in Algebraic Graph Theory 
Tues Oct 18 / 2:30 / K9509  Krystal Guo, SFU  Quantum Walks on Strongly Regular Graphs 
Tues Oct 25 / 2:30 / K9509  KaiUwe Schmidt, SFU  The peak sidelobe level of binary sequences 
Tues Nov 1 / 2:30 / K9509  Sam Johnson, SFU  Analytic combinatorics of walks with small steps in the quarter plane. 
Tues Nov 8 / 2:30 / K9509  Vasu Tewari, UBC  Computation of certain Kronecker coefficients 
Tues Nov 15 / 2:30 / K9509  Andrew King, SFU  Proving the LovászPlummer Conjecture 
Tues Nov 22 / 2:30 / K9509  Pavel Rytir (Charles University, Prague)  Geometric Representations of Linear Codes 
Mon Nov 28 / 1:30 / K9509  Michael Kozdron, Regina  A Random Look at the SchrammLoewner Evolution 
Tues Dec 6 / 2:30 / TASC2 8500  Bojan Mohar, SFU  5choosability of graphs with crossings 
Summer 2011
Tue May 17 / 2:30 / K9509  Bruno Salvy, INRIA Rocquencourt 
Newton's Iteration for Combinatorial Systems and Applications 
Tue May 24 / 2:30 / K9509  Steven Chaplick, Toronto 
Characterizing Path Graphs and Directed Path Graphs using PRtrees 
THURS May 26 / 1:30 / K9509  Ararat Harutyunyan, SFU  On the digraph chromatic number 
Tue May 31  CANADAM Victoria (No seminar) 

Tue June 7/ 2:30 / K9509  Loic Foissy, U. Reims  Free and cofree combinatorial Hopf algebras 
Tue June 14/ 2:30 / K9509  Juraj Stacho, University of Haifa, Israel  Unique perfect phylogeny is NPhard 
THURS June 16 1:30/ K9509  Mathew Francis, SFU 
Contact representations of planar graphs with cubes 
Tue June 21/ 2:30 / K9509  Matt Devos, SFU  Immersing Complete Graphs 
Tue June 28/ 2:30 / K9509  Sophie Burrill, SFU 
Understanding nestings in RNA 
Tue/ July 5/2:30/ K9509  
Tue/ July 12/2:30/ K9509  Ed Richmond, UBC  LittlewoodRichardson coefficients and tight fusion frames 
Spring 2011
Tue Jan 18 / 2:30 / K9509  Ladislav Stacho, SFU  Strong Orientations of Plane Graphs with Bounded Stretch Factor 
Tue Jan 25 / 2:30 / K9509  Jonathan Jedwab, SFU 
The asymptotic merit factor of binary sequences 
Tue Feb 1 / 2:30 / K9509  Roi Krakovski, University BenGurion  Subdivisions in Graphs 
Tue Feb 8 / 2:30 / K9509  Sam Black, SFU  A new state model for the Alexander polynomial 
Tue Feb 22 / 2:30 / K9509  Winfried Hochstaettler, FernUniversität 
Some heuristics for the binary paint shop problem and their expected number of colour changes 
Tue March 1 / 2:30 / K9509  Pavol Hell, SFU  Obstruction Characterizations in Graph Partition Problems 
Tue March 8 / 2:30 / K9509  Diegeo Scheide, SFU 
Average degree in graph powers 
Tue March 15 / 2:30 / K9509  Lino Demasi, SFU  Domination in Plane Triangulations 
Tue March 22 / 2:30 / K9509  Sergi Elizalde, Dartmouth  A greedy sorting algorithm 
Tue March 29/ 2:30 / K9509  Daniel Katz, SFU  The Inevitability of 1 in ThreeValued CrossCorrelations of Maximal Sequencesï 
Tue April 5 / 2:30 / K9509  Gelasio Salazar, Universidad Autonoma de San Luis Potosi/ Waterloo 
Recent progress on Turan's Brickyard Problem 
Tue April 12 / 2:30 / K9509  Mahdad Khatirinejad, UBC 
Steiner Triple Systems Satisfying the 4Vertex Condition 
Tue April 19 / 2:30 / K9509  CANCELLED 
Seminars 20012010
Fall 2010  
Tue Sept 14 / 2:30 / K9509  Zdenek Dvorak  Choosability of planar graphs + Welcome party 
Tue Sept 21 / 2:30 / K9509  Jessica McDonald, SFU  Characterizing high chromatic index 
Tue Sept 28 / 2:30 / K9509  Emmanuel Godard, CNRS/ U. Aix (Marseilles)  Using isometric embeddings in distributed algorithms for the median problem in partial rectangular grids and their relatives 
Tue Oct 5 / 2:30 / K9509  Mohamed Omar, UC Davis.  Graph Automorphism and Permutation Groups via Polytopes 
Tue October 12 / 2:30 / K9509  Karen Yeats, SFU  The support of power series given by systems of equations 
Tue October 19 / 2:30 / K9509  Cedric Chauve, SFU  On matrices that do not have the ConsecutiveOnes Property. 
Tue October 26 / 2:30 / K9509  Andrew Crites, U. Washington  Affine permutations and pattern avoidance 
Tue Nov 2 / 2:30 / K9509  Petr Lisonek, SFU  Nonlinear functions 
Tue Nov 9 / 2:30 / K9509  Flavio Guinez, UBC  The reconstruction of a colored grid by its projections: a solution to the 2atom problem in discrete tomography 
Tue November 16 / 2:30 / K9509  Amites Sarkar, UWW  Partitioning geometric covers 
Tue November 23 / 2:30 / K9509  Kurt Luoto, UBC  Quasisymmetric and noncommutative Schur functionsï»¿ 
Tue Nov 30 / 2:30 / K9509  Aki Avis, SFU  3Phase Golay Triads 
Tue Dec 7 / 2:30 / K9509  Pradeep Sarvepalli (UBC)ï»¿  Topological color codes over prime power alphabet 
Satruday December 11 (Western Washington University)  Combinatorial potlatch  Richard Guy, University of Calgary Christine Kelley, University of Nebraska, Lincoln KaiUwe Schmidt, Simon Fraser University 
Tue Dec 14 / 2:30 / K9509  Bruce Shepherd  Minimum Cost Networks Supporting All Matchings 
Summer 2010  
Tue 08 Jun / 2:30 / K9509  John Stardom, Statistics Canada  Sample Stratification and Allocation: an Application to Statistics Canada's Unified Enterprise Survey 
Tue 22 Jun / 2:30 / K9509  Christian Stump, CRM/ LaCIM UQAM  Noncrossing and nonnesting partitions and the cyclic sieving phenomenon 
Tue 07 July / 2:30 / K9509  Karel Casteels, SFU  Combinatorial aspects of the prime spectrum of quantum matrices 
Tue 13 July / 2:30 / K9509  Guillaume Chapuy, SFU  Covered Maps on Orientable Surfaces 
Tue 10 August / 2:30 / K9509  KaiUwe Schmidt, SFU  Appended msequences with merit factor greater than 3.34 
Spring 2010 

Tue 09 Feb / 3:30 / TASC2 8500  Kevin Milans, U. Illinois UC  Degree Ramsey Numbers of Graphs 
Tue 02 Mar / 3:30 / TASC2 8500  Ararat Harutyunyan, SFU  Independent dominating sets in graphs of girth five 
Thu 04 Mar / 1:00 / K 9509  Adolfo Rodriguez, LaCIM UQAM  Bugs, colonies, and qBoson normal ordering 
Tue 23 Mar / 3:30 / TASC2 8500  Roland Wittler, Bielefeld and SFU.  Phylogenybased Analysis of Gene Clusters 
Thu 25 Mar / 1:00 / K 9509  Justin Chan, University of Victoria  The LamkenWilson Theorem and Its Applications 
Mon 12 Apr / 2:30 / IRMACS Theatre, ASB 10900, SFU  Peter Horak, U. Washington, Tacoma  Tiling nspace by cubes 
Tue 13 Apr / 3:30 / TASC2 8500  Alejandro Erickson, University of Victoria  Negative correlation properties for graphs 
Tue 20 Apr / 3:30 / TASC2 8500  Robert Samal, Charles University, Prague  Star Chromatic Index 
Fall 2009 

Tue 22 Sep / 1:30 / K9509  Bojan Monar, SFU  How useful can the spectral radius of a graph be? 
Tue 29 Sep / 1:30 / K9509  Ladislaw Stacho  Cyclic colorings of plane graphs with independent faces 
Tue 06 Oct / 1:30 / K9509  Guillaume Chapuy  Maps on surfaces : asymptotic enumeration and metric properties. 
Tue 13 Oct / 1:30 / K9509  Andrea Spencer, SFU  Title: Efficient Edge List Colouring of Cubic Planar Graphs 
Tue 27 Oct / 1:30 / K9509  Mahdad KhatirinejadFard, Helsinki U. of Tech.  Title: Edgeweighting vertex colouring of (di)graphs 
Sat 21 Nov / 10:00 / Labatt Room  2009 Combinatorial Potlach, SFU Harbour Centre  Speakers: TBA 
Summer 2009 

Tue 05 May / 2:00 / TASC2 8500  Daniel Kral, Charles U., Prague  Removal Lemma for systems of linear equations 
Tue 25 Aug / 3:30 / K9509  Gena Hahn, U. de Montreal  Cops and Robbers on Infinite Graphs 
Tue 01 Sep / 3:30 / K9509  Robert Samal, Charles U., Prague  Cubical chromatic number, spherical chromatic number, and Lovasz theta function 
Spring 2009  
Tue 10 Feb / 3:30 / K9509  Robert Bailey, Carleton University  Packing spanning trees in graphs and bases in matroids 
SatSun 2122 Feb, Univ. of Victoria  11th Coast Combinatorics Conference  
Tue 24 Feb / 3:30 / K9509  Markus Grassl, Centre for Quantum Technologies (NUS), Singapore  Searching for good errorcorrecting codes 
Tue 31 Mar / 3:30 / K9509  Hernando Bermudez, University of Montana  Sheduling Tournaments with Home and Away Constraints 
Tue 24 Mar / 3:30 / K9509  Natasa Przulj, UC Irvine  From Network Topology to Biological Function and Disease 
Tue 14 Apr / 3:30 / K9509  Cedric Chauve  Enumerative results for graph decompostion trees 
Tue 21 Apr / 3:30 / K9509  Eric Fusy  Schnyder woods generalized to higher genus surfaces 
Tue 28 Apr / 3:30 / K9509  Bruce Richter, University of Waterloo  Do we really know what characterizes planarity? 
Fall 2008 

Tue 23 Sep / 3:30 / K9509  Juanjo Ru\'e, Politechnical U. of Catalonia  On a question of S\'arkozy and S\'os on bilinear forms 
Thu 02 Oct / 1:30 / K9509  Mireille BousquetMelou, CNRS, Bordeaux  Enumeration of colored planar maps 
Tue 14 Oct / 3:30 / K9509  Eli Berger, Univeristy of Haifa  Using classical topology in combinatorial problems. 
Tue 28 Oct / 2:30 / ASB 10900  David Brydges, CRC Chair, UBC  Combinatorics with Gaussian Integreals 
Tue 04 Nov / 3:30 / K9509  Kenichi Kawarabayashi, Nat. Inst. of Informatics, Japan  From the Plane to Higher Surfaces 
Tue 18 Nov / 3:30 / K9509  Aida Ouangraoua, SFU  Algorithmic tools to compare treestructured biological objects 
Sat 22 Nov / 10:00 / U.P.S.  2008 Combinatorial Potlach, U. Puget Sound, Tacoma  Speakers: E. Fusy + C. Dunn + I. Dumitriu 
Tue 02 Dec / 3:30 / K9509  Brian Alspach, U. Newcastle  Hamilton paths in vertextransative graphs 
Summer 2008 

Tue 06 May / 3:30 / K9509  Bojan Mohar, SFU  On the sum of k largest eigenvalues of graphs and symmetric matrices 
Tue 20 May / 3:30 / K9509  Simon Spacapan, SFU  The Acyclic, the Star, and the Degenerate Chromatic Numbers 
Tue 22 Jul / 3:30 / K9509  Winfried Hochstaettler, U. of Hagen, Germany  Flows in Oriented Matroids and a Chromatic Number 
Tue 19 Aug / 2:30 / TASK 9204  David Coudert, CNRS U. Nice Sophia  Survivability and Routing in Oriented Networks 
Spring 2008 

Tue 15 Jan / 3:30 / K9509  Maia Fraser, U. Colima, Mx  Local routing on higher surfaces 
Tue 25 Feb / 3:30 / K9509  Gabor Kun, Etvos University, Hungary  Cops and robbers in random graphs 
Tue 04 Mar / 3:30 / K9509  Luis Goddyn, Simon Fraer University  How bad can a Euclidean Traveling Salesman Problem be? 
Tue 11 March / 3:30 / TASC2 8500  Penny Haxell, University of Waterloo  More on Sperner's Lemma 
Tue 25 March / 3:30 / K9509  Agelos Georgakopoulos, University of Hamburg  Infinite cycles in graphs 
Tue 25 March / 3:30 / K9509  Marni Mishna, Simon Fraser University  Decomposition and Enumeration of Planar Graphs, Part I: Combinatorial Warm Up 
Tue 01 April / 3:30 / K9509  Eric Fusy, Simon Fraser University  Decomposition and Enumeration of Planar Graphs, Part II 
Tue 08 April / 3:00 / K 9509  Laura Chavez, Simon Fraser University  Flow and chromatic numbers for matroids (reception to follow) 
Tue 15 April / 3:30 / K 9509  Derek Bingham, Simon Fraser University  Defining contrast subspaces and the randomization structure of factorial designs 
Tue 29 April / 3:30 / K 9509  Sean McGuinness, Thompson Rivers University  Perfect Path Double Covers, Matroids, A Theorem of Fan, ... And A Problem of Goddyn. 
Fall 2007 

Tue 25 Sep / 10:30 / ASB10900  Luis Goddyn, SFU (Coast to Coast)  Spectra of (3,6)Fullerenes 
Tue 25 Sep / 2:30 / TASC2 8500  Mark Siggers, SFU  Integer packings of hypergraphs through fractional packings 
Sat 29 Sep / 11:00 / U. Victoria  2007 Combinatorial Potlach  Speakers: Perkel + Moon + Quas 
Tue 02 Oct / 2:30 / TASC2 8500  Robert Samal, SFU  Trading Handles for Crossings 
Tue 09 Oct / 2:30 / TASC2 8500  Blair D Sullivan, Princeton  Feedback Arc Sets in Circular Interval Digraphs 
Tue 23 Oct / 2:30 / TASC2 8500  Gabor Kun, SFU  An asymptotic version of the BollobasCatlinEldridge conjecture 
Tue 30 Oct / 2:30 / TASC2 8500  Matthias Koeppe, U. Magdeburg, de  Topic: Ehrhart polynomials of matroid polytopes 
Tue 06 Nov / 2:30 / TASC2 8500  Eric Fusy, SFU  Transversal structures on triangulations: combinatorial study and algorithmic applications 
Tue 13 Nov / 2:30 / TASC2 8500  Vladmir Korzhik, Nat. U. Chernivtsi, Ukraine  Some open problems on the set of triangular embeddings of a complete graph 
Tue 27 Nov / 2:30 / TASC2 8500  Frederic Giroire, Intel Research  Probabilistic algorithms to compute the cardinality of very large datasets 
Summer 2007 

Tue 15 May / 3:30 / ASB10908  Ambat Vijayakumar  Graph operators and cographs: some recent trends 
Fri 18 May / 1:30 / ASB10900  Andre Raspaud  Injective Colourings of Graphs 
Tue 22 May / 3:30 / ASB10908  Jonathan Jedwab, SFU  Golay complementary sequences: a multidimensional approach 
Thu 24 May / 11:30 / ASB10900  Janos Pach  Decomposition of multiple coverings 
Fri 25 May / 2:30 / ASB10900  Herbert Wilf  Mathematics: An experimental science 
Fri 31 Aug / 2:30 / 1430 SFU Harbour Centre  Paul Seymour  Structure Theorems in Graph Theory 
Spring 2007 

Tue 30 Jan / 3:30 / ASB10908  Azhvan SheikhAhmady, SFU  Eigenvalues of Cayley graphs and group characters. 
Tue 6 Feb / 3:30 / ASB10908  Cedric Chauvre, SFU  Inferring ancestral genomes with common intervals 
Tue 20 Feb / 3:30 / ASB10908  Neil Robertson, Ohio State U.  CANCELLED 
SatSun 2425 Feb /9:30 / U. Victoria  Eighth Coast Combinatorics Conference  Speakers: Several 
Tue 27 Feb / 3:30 / ASB10908  Gena Hahn, Universite de Montreal  CANCELLED 
Tue 06 Mar / 3:30 / ASB10908  Francois Bergeron, UQAM  A combinatorial classification of polynomials 
Tue 13 Mar / 3:30 / ASB10908  Mike Zabrocki, York U.  A Zoo of Hopf Algebras 
Tue 20 Mar / 3:30 / ASB10908  Robert Samal, SFU  On XY mappings 
Tue 27 Mar / 3:30 / ASB10908  Jonathan Jedwab, SFU  On XY mappings 
Fall 2006 

Tue 26 Sep / 3:30 / ASB10908  Tamon Stephen, SFU  Colourful Simplicial Depth 
Wed 27 Sep / 3:30 / ASB9705  Eyal Ackerman, SFU  Maximum size of a $k$quasiplanar graphs 
Tue 10 Oct / 3:30 / (UBC) WMAX110  Joachim Rosenthal, U. Zurich  Three challenges of Claude Shannon 
Tue 17 Oct / 3:30 / ASB10908  Tomas Kaiser, U. West Bohemia  Nonintersecting perfect matchings in cubic graphs 
Tue 31 Oct / 2:30 / ASB10900  Dragos Cvetkovic, U. of Belgrade  Signless Laplacians of finite graphs 
Sat 11 Nov / 10:00 / Portland State U.  2006 Combinatorial Potlach  Speakers: Brualdi + Gordon + DeVos 
Tue 21 Nov / 3:30 / ASB10900  Kevin Purbhoo, UBC  Puzzles, Tableaux, and Mosaics 
Tue 05 Dec / 3:30 / (UBC) WMAX110  John Gimbel, University of Alaska  Remarks on split graphs and related notions 
Tue 12 Dec / 2:30 / ASB10900  Moshe Rosenfeld, University of Washington, Tacoma  Spanning Graph Designs, an extension of the "Graph disease" 
Tue 12 Dec / 3:30 / ASB10900  John Irving, St. Mary's University  Counting Transitive Factorizations in the Symmetric Group 
Summer 2006 

Tue 7 May / 3:30 / ASB10908  Winfried Hochstaettler, Fern Univ at Hagen  Online matching on a line 
Thu 22 Jun / 9:30 / ASB10900  SFU Discrete Math Day  Seven talks by distinguished visitors 
Thu 29 Jun / 2:30 / AQ 3149  Winfried Hochstaettler, Fern Univ at Hagen  On the game chromatic index of trees 
Tue 4 Jul / 3:30 / K9509  Brian Lucena, American Univ. in Cairo  Minimal forbidden minors for treewidth 
Tue 8 Aug / 3:30 / ASB10900  Jacob Fox  Ramseytype results for intersection graphs:w 
Spring 2006  
Tue 24 Jan / 3:30 / ASB10900  Maria Chudnovski, Princeton U.  The structure of bullfree graphs 
Tue 14 Feb / 3:30 / ASB10900  Luis Goddyn, SFU  Silver Cubes 
Tue 28 Feb / 3:30 / (UBC) WMAX216  Shakhar Smorodinsky, Courant Inst.  On Ksets in dimensions 2, 3 and 4. 
Tue 14 Mar / 3:30 / ASB10900  Arie Bialostocki, University of Idaho  Some Problems in View of Recent Developments of the Erdos Ginzburg Ziv theorem 
Tue 21 Mar / 3:30 / ASB10900  Susan Barwick, University of Adelaide  The geometry of linear perfect hash families 
Tue 28 Mar / 3:30 / (UBC) WMAX216  Kee Yuen Lam, UBC  The combinatorics of sums of squares as studied via topology 
Tue 4 Apr / 3:30 / ASB10908  Aidan Roy, University of Waterloo  Equiangular lines, mutually unbiased bases, and difference sets 
Fall 2005  
Tue 13 Sep / 3:30 / (UBC) WMAX216  Gabor Tardos, SFU  Toward and Extremal Theory of Ordered Graphs 
Tue 20 Sep / 3:30 / ASB10908  Brian Alspach, University of Regina  Time constrained searching and sweeping 
Tue 27 Sep / 3:30 / ASB10908  Richard Anstee, UBC  Forbidden Configurations: An update 
Tue 04 Oct / 3:30 / EAA1100  Matt DeVos, SFU  Pentagon Colouring 
Tue 11 Oct / 3:30 / ASB 10900  Bojan Mohar, SFU  Quadrangulations, Eulerian triangulations, and 5critical graphs 
Tue 25 Oct / 3:30 / (UBC) WMAX216  David Kirkpatrick, UBC  Minimizing precision/input in the evaluation of geometric primitives 
Tue 08 Nov / 3:30 / (UBC) WMAX216  Luis Goddyn, SFU  An Optimization Problem Arising from VideoonDemand Broadcasting 
Wed 09 Nov / 3:30 / ASB10908  Santosh Kabadi, U New Brunswick  Integer Exact Network Synthesis Problem 
Tue 15 Nov / 3:30 / ASB10908  Jonathan Jedwab, SFU  Proof of the Barker Array Conjecture 
Sat 19 Nov / 10:30 / Seattle U.  2005 Combinatorial Potlach  Speakers: Mohar + Quinn + Caughman 
Summer 2005  
Tue 03 May / 3:30 / EAA1100  Cedric Chauve, Universite du Quebec a Montreal  Conservation of combinatorial structure in genome rearrangement scenarios 
Tue 17 May / 3:30 / EAA1100  Rados Radoicic, Rutgers University  Intersection patterns of geometric objects 
Tue 31 May / 3:30 / EAA1100  Danny Dyer, University of Regina  Digraphs with small sweep number 
Tue 21 Jun / 3:30 / EAA1100  Anna Galluccio, IASICNR, Roma, Italy  Regular Join Graphs 
Tue 28 Jun / 3:30 / ASB 10900  CANCELLED: Mordecai Golin, Hong Kong U. of Science  The KnuthYao QuadrangleInequality & TotalMonotonicity 
Wed 06 Jul / 3:30 / ASB 10900  Ebad Mahmoodian, Sharif University  Problems and Motivations 
Tue 19 Jul / 3:30 / EAA1100  Ron Aharoni, Technion Institute, Israel  Topological Methods in Matching Theory 
Spring 2005  
Tue 18 Jan / 3:30 / EAA1100  Colin Percival, University of Oxford  Matching with mismatches 
Thu 10 Feb / 3:30 / EAA1100  Peter Horak, University of Washington  Completing Latin squares 
Tue 15 Feb / 3:30 / EAA1100  Binay Bhattacharya, Simon Fraser University  Collection depots problem on networks 
Tue 22 Feb / 3:30 / EAA1100  Evangelos Kranakis, Carleton University  The Mobile Agent Rendezvous Problem 
Mon 28 Feb / 4:00 / K9509  Chris Mitchell, Royal Holloway  Cryptanalysis of methods for combining confidentiality and integrity 
Tue 1 Mar / 3:30 / EAA1100  Nati Linial, U. Washington & Hebrew University  Finite Metric Spaces  A quick overview 
Tue 15 Mar / 3:30 / EAA1100  Frank Fiedler, Simon Fraser University  The Search for More Golay Sequences 
Tue 22 Mar / 3:30 / EAA1100  Petr Lisonek, Simon Fraser University  Enumeration of Codes of Fixed Cardinality up to Isomorphism 
Tue 29 Mar / 4:30 / AQ 3182  Laszlo Lovasz, Microsoft Research and Eotvos Lorand University  Graph homomorphisms, statistical physics, and limits of graph sequences 
Tue 05 Apr / 3:30 / EAA1100  Boaz Benmoshe, Simon Fraser University  Guarding 1.5D terrains 
Fall 2004  
Tue 21 Sep / 2:30 / K9509  Abraham P. Punnen, University of New Brunswick  The number of distinct tour values for the traveling salesman problem: one, two, three, all 
Tue 28 Sep / 3:30 / EAA1100  Arash Rafiey, University of London  Characterization of edgecolored complete graphs with properly colored Hamilton paths 
Tue 5 Oct / 3:30 / EAA1100  Frank Fiedler, Simon Fraser  On the degree of Mathon maximal arcs 
Tue 12 Oct / 3:30 / EAA1100  Jonathan Jedwab, Simon Fraser  A survey of the merit factor problem for binary sequences 
Tue 19 Oct / 3:30 / EAA1100  Ladislav Stacho, Simon Fraser  Asymptotics of random RNA 
Tue 26 Oct / 3:30 / EAA1100  Jeffrey Farr, Simon Fraser  Large caps with free pairs in PG(N,q) 
Tue 2 Nov / 3:30 / EAA1100  Mohammad Ghebleh, Simon Fraser  Circular chromatic number of evenfaced torus graphs 
Tue 9 Nov / 3:30 / EAA1100  Petr Lisonek, Simon Fraser  Variable rate linear codes with an application to steganography 
Tue 16 Nov / 3:30 / EAA1100  Luis Goddyn, Simon Fraser  Two results for the Lonely Runner 
Sat 20 Nov / 10:30 / Harbour Centre  Combinatorial Potlatch 2004  
Tue 23 Nov / 3:30 / EAA1100  Pavol Hell, Simon Fraser  Matrix partitions of perfect graphs 
Tue 30 Nov / 3:45 / EAA1100  Xuding Zhu, National Sun Yatsen University  Circular coloring of Kneser graphs, Schrijver graphs and cones over graphs 
Tue 7 Dec / 3:30 / EAA1100  Victor Dalmau, Universitat Pompeu Fabra  Constraint Satisfaction Problems and Expressiveness 
Summer 2004  
Tue 18 May / 3:30 / EAA1100  Daniel Kral, Charles University  Circular edgecolorings of graphs with large girth 
Fri 28 May / 11:30 / EAA1100  Peter Pleasants, University of Queensland  Almost disjoint families of 3term arithmetic progressions 
Fri 28 May / 2:30 / K9509  Nantel Bergeron, York University  Combinatorial Hopf algebras 
Mon 31 May / 2:30 / K9509  Bojan Mohar, University of Ljubljana  Graph minors and graphs on surfaces 
Tue 29 Jun / 2:30 / K9509  Marni Mishna, LaBRI, University of Bordeaux  On the utility of effective Dfinite symmetric functions in combinatorics 
Tue 13 Jul / 3:30 / EAA1100  Bruce Reed, McGill University  Vertex Colouring Edge Weightings 
Tue 20 Jul / 2:30 / K9509  Nadya Shirokova, Inst. Hautes Etudes Sci.  Space approach to invariants for families 
Tue 27 Jul / 10:00 / Halpern Centre, Room 126  Roman Nedela, Slovak Academy of Sciences  Regular maps  combinatorial objects relating different fields of mathematics 
Tue 10 Aug / 3:30 / EAA1100  Moshe Rosenfeld, University of Washington  Prisms over graphs 
Tue 17 Aug / 3:30 / EAA1100  Tomas Kaiser, University of West Bohemia  Eulerian colorings of graphs 
Spring 2004  
Tue 20 Jan / 3:30 / EAA1100  Jim Davis, Math & CS, U of Richmond  Polynomial arithmetic behind the IEEE 802.12 standard for 100Mbit/s data transmission 
Tue 27 Jan / 3:30 / EAA1100  Jeffrey Farr, Mathematics, SFU  A new polynomial construction for some linear codes 
Tue 03 Feb / 3:30 / EAA1100  Petr Lisonek, Mathematics, SFU  Binary caps with many free pairs of points 
Tue 10 Feb / 3:30 / EAA1100  Jan Manuch, Computing, SFU  Inverse protein folding in 2D HP model 
Tue 17 Feb / 3:30 / EAA1100  SEMINAR CANCELLED  Reading break 
Tue 24 Feb / 3:30 / EAA1100  Ladislav Stacho, Mathematics, SFU  Traversal of quasiplanar subdivisions without using mark bits 
Tue 01 Mar / 3:30 / EAA1100  Chris Mitchell, U of London, UK  Universal cycles of permutations 
Tue 02 Mar / 3:30 / EAA1100  Mahdad Khatirinejad Fard , Mathematics, SFU  ICColorings and ICindices of graphs 
Thu 11 Mar / 11:30 / K9509 (!)  Juergen Bierbrauer, Michigan Technological University  Cyclic codes and their applications 
Tue 16 Mar / 3:30 / EAA1100  Veselin Jungic, Mathematics, SFU  Rainbow Ramsey Theory 
Tue 23 Mar / 3:30 / EAA1100  Van Vu, Mathematics, UCSD  ErdosFolkman conjecture 
Tue 30 Mar / 3:30 / EAA1100  Luis Goddyn, Mathematics, SFU  From graceful labelings to Heawood embeddings 
Tue 06 Apr / 3:30 / EAA1100  Jozsef Solymosi, Mathematics, UBC  Applications of hypergraph regularity 
Fall 2003  
Tue 30 Sep / 3:30 / EAA1100  Jan Manuch, Math & CS, SFU  On fwise Arc Forwarding Index and Wavelength Allocations in Faulty Alloptical Networks 
Tue 07 Oct / 3:30 / EAA1100  Luis Goddyn, Mathematics, SFU  Packing Groupnonvanishing Apaths 
Tue 14 Oct / 3:30 / EAA1100  Ladislav Stacho, Mathematics, SFU  Closure for the Property of Having a Hamiltonian Prism 
Tue 21 Oct / 3:30 / EAA1100  Petr Lisonek, Mathematics, SFU  A New Application of the Linear Programming Method in Coding Theory 
Tue 04 Nov / 3:30 / EAA1100  Russel Martin, Computing, U of Warwick  Rapidly Mixing Markov Chains for Sampling Contingency Tables with a Constant Number of Rows 
0810 Nov / / UVic  Combinatorial Potlatch and 5th Coast Combinatorics Conference  
Thu 13 Nov / 3:30 / EAA1100  Zdenek Ryjacek, Mathematics, U of West Bohemia  Closure Concepts, Stable Properties and Forbidden Subgraphs for Hamiltonicity 
Tue 18 Nov / 3:30 / AQ 3149  Helaman and Claire Ferguson  Mathematics in Stone and Bronze (The Alan Mekler Lecture) 
Tue 25 Nov / 3:30 / EAA1100  Alireza Hadj Khodabakhshi, Computing, SFU  A Fast Algorithm for Finding a Global Alignment Between Two Genomes 
Spring 2003  
Tue 07 Jan / 3:30 / EAA1100  Reza Naserasr, Mathematics, SFU  Homomorphisms of Planar Graphs 
Tue 14 Jan / 3:30 / EAA1100  Pavol Hell, Mathematics/Comp. Sci., SFU  Interval Bigraphs and Circular Arc Graphs 
Tue 21 Jan / 3:30 / EAA1100  Romeo Rizzi, University of Trento (Italy)  Permutation Routing on POPS Networks 
Tue 28 Jan / 3:30 / K9509 (!)  Nantel Bergeron, Mathematics and Statistics, York University  Quasisymmetric Polynomials and TemperleyLieb Invariants and Covariants 
Tue 11 Feb / 3:30 / EAA1100  Tom Friedetzky, Comp. Sci., SFU  A Proportionate Fair Scheduling Rule with Good Worstcase Performance 
Tue 18 Feb / 3:30 / EAA1100  Jan Manuch, SFU  Equations on Words and Defect Theorems 
Tue 25 Feb / 10:30 (!) / K9509  Wendy Myrvold, University of Victoria  Hunting for Torus Obstructions 
Tue 25 Feb / 3:30 / EAA1100  Jaroslav Nesetril, Charles University, Prague  Ramsey Classes and Homogeneous Graphs 
Tue 04 Mar / 3:30 / EAA1100  Veselin Jungic, Mathematics, SFU  Colorings of Plane Graphs with No Rainbow Faces 
Tue 11 Mar / 3:30 / EAA1100  Jessie Zhu, SFU  Phylogenetics Incorporating Stratophenetics 
Tue 18 Mar / 3:30 / EAA1100  Riste Skrekovski, PIMS/SFU  Coloring 1001 Maps on Surfaces 
Tue 25 Mar / 3:30 / EAA1100  Stephanie van Willigenburg, Mathematics, U. British Columbia  Acyclic Orientations and Excedence Permutations 
Tue 15 Apr / 10:30 (!) / ASB 9896 (!)  Yuri Gurevich, Microsoft Research  What is Polynomial Time Anyway? 
Tue 15 Apr / 3:30 / EAA1100  Joel Friedman, Mathematics, U. British Columbia  A Proof of Alon's Second Eigenvalue Conjecture 
Tue 29 Apr / 3:30 / EAA1100  Michael Molloy, Microsoft Research and University of Toronto  Random Constraint Satisfaction Problems, aka Homomorphisms of Random Hypergraphs 
Fall 2002  
Tue 10 Sep / 2:00 / EAA1100  Juan Jose MontellanoBallesteros, UNAM Mexico  Polychromatic Cliques 
Tue 17 Sep / 2:00 / EAA1100  Ladislav Stacho, Mathematics, SFU  Edgedisjoint Spanners in Multidimensional Torus 
Tue 24 Sep / 2:00 / EAA1100  Jan Manuch, SFU  On the Descriptional and Computational Complexities of Infinite Words 
Tue 01 Oct / 2:00 / EAA1100  Tom Brown, Mathematics, SFU  On the Canonical Version of a Simple Theorem in Ramsey Theory 
Tue 08 Oct / 2:00 / EAA1100  Petr Lisonek, Mathematics, SFU  A Family of Complete Caps in PG(n,2) 
Tue 15 Oct / 2:00 / EAA1100  Riste Skrekovski, PIMS/SFU  Cyclic, Diagonal, and Facial Colorings 
Tue 22 Oct / 2:00 / EAA1100  Veselin Jungic, Mathematics, SFU  Radoicic's Conjecture and Tight Graphs 
Tue 29 Oct / 2:00 / EAA1100  Bruce Reed, McGill University  Tree Width and Excluded Minors 
Tue 05 Nov / 2:00 / EAA1100  Richard Anstee, Mathematics, U. British Columbia  Forbidden Configurations 
Sat 09 Nov / 116 / UVic  A. Proskurowski, B. Grunbaum, J. Siran  Combinatorial Potlatch at UVic 
Tue 12 Nov / 2:00 / EAA1100  Qianping Gu, Comp. Sci., SFU  A 1.8Approximation Algorithm for Embedding Hypergraphs in a Cycle 
Tue 19 Nov / 2:00 / EAA1100  Daniel Kral, Charles University  Channel Assignment Problem 
Thu (!) 21 Nov / 2:00 / EAA1100  Vadim V. Lozin, Rutgers  Boundary Classes of Graphs for NPhard Problems 
Tue 26 Nov / 2:00 / EAA1100  Ron Ferguson, PIMS/SFU  Polyphase Sequences with Low Autocorrelation 
Tue 03 Dec / 2:00 / EAA1100  Cynthia Loten , Mathematics, SFU  Retractions and a Generalization of Chordal Graphs 
Summer 2002 

Tue 14 May / 3:30 / EAA1100  Rados Rodoicic, MIT  Rainbow Arithmetic Progressions 
Tue 28 May / 3:30 / EAA1100  Sean McGuinness, U. Umea and Montana  Circuits intersecting cocircuits in graphs and matroids. 
Tue 11 Jun / 3:30 / EAA1100  Claude Tardif, U. Regina  The projectivity of the graphs $G_d^k$ 
Tue 18 Jun / 3:30 / K9509  Joergen BangJensen, U. Southern Denmark  Steiner type problems in tournamentlike digraphs 
Tue 25 Jun / 3:30 / K 9500 (!)  Winfried Hochstaettler, Brandenburg U. of Tech.  Maxflow mincut duality for a paint shop problem 
Tue 02 Jul / 3:30 / EAA1100  Luis Goddyn, Mathematics, SFU  Flows and Tensions on maps of high edge width. 
Tue 09 Jul / 3:30 / EAA1100  Peter Higgins, Mathematics,  Sur une Th\'eor\`eme de Sierpi\'nsk (In English!) 
Tue 16 Jul / 3:30 / EAA1100  KheeMeng Koh, Nat. U. of Singapore  On the Chromaticity of graphs 
Tue 23 Jul / 3:30 / EAA1100  UBC PiMS Event  Lovasz  See their program for titles and abstracts. 
Tue 30 Jul / 3:30 / EAA1100  Marnie Mishna  Enumeration via Dfinite Symmetric Functions 
Tue 6 Aug / 3:30 / EAA1100  Luis Goddyn  Chromatic numbers of matroids 
Tue 6 Aug / 3:30 / EAA1100  Bill McCuaig  Edmonds' arcdisjoint arborescences theorem 
Spring 2002 

Tue 05 Feb / 3:30 / EAA1100  Reza Naserasr, Math, SFU  Homomorphisms from sparse graphs with large girth. 
Tue 12 Feb / 3:30 / EAA1100  Qianping Gu, CS, SFU  Permutation routing on WDM optical hypercubes I. 
Tue 19 Feb / 3:30 / EAA1100  Qianping Gu, CS, SFU  Permutation routing on WDM optical hypercubes II. 
Tue 05 Mar / 3:30 / EAA1100  Luis Goddyn, Math, SFU  Graph coloring and Matroids. 
Tue 05 Mar / 3:30 / EAA1100  Tom Friedetzky, CS, SFU  The Natural WorkStealing Algorithm is Stable 
Tue 19 Mar / 3:30 / EAA1100  Petr Lisonek, Math, SFU  Caps and Binary Linear Codes 
Tue 26 Mar / 3:30 / EAA1100  Petra Berenbrink, CS, SFU  Simple routing strategies for Adversarial networks. 
Tue 02 Apr / 3:30 / EAA1100  Pavol Hell, CS/Math, SFU  Complexity of generalized listcolourings. 
Tue 09 Apr / 3:30 / EAA1100  Laco Stacho, Math, SFU  Edgedisjoint spanners in the Cartesian product of graphs 
Fall 2001  
Tue 18 Sep / 3:30 / EAA1100  Luis Goddyn, Math, SFU  Binary Gray Codes with long bit runs. 
Tue 25 Sep / 3:30 / EAA1100  Louis Ibarra, CS, SFU  The cliqueseparator graph for chordal graphs and its subclasses. 
Tue 02 Oct / 3:30 / EAA1100  Ladislav Stacho, Math, SFU  New upperbound for chromatic number. 
Tue 09 Oct / 3:30 / EAA1100  Amitava Bhattacharya, TIFR  A short proof of a EKR type theorem. 
Tue 16 Oct / 3:30 / EAA1100  Juan Montellano, UNAM  AntiRamsey Problems. 
Tue 23 Oct / 3:30 / EAA1100  Ladislav Stacho, Math, SFU  Spannin trees with bounded number of branch vertices. 
Tue 30 Oct / 3:30 / EAA1100  Bill McCuaig, Math, SFU  The Hat Game. 
Tue 06 Nov / 3:30 / EAA1100  Mohammad Ghebleh, Math, SFU  Uniuqely list colorable graphs. 
Tue 13 Nov / 3:30 / EAA1100  Petr Lisonek, Math, SFU  Geometric Representations of Graphs. 
Tue 20 Nov / 3:30 / EAA1100  Luis Goddyn, Math, SFU  Using the Nullstellensatz for edge list colouring. 
Tue 27 Nov / 3:30 / EAA1100  Reza Naserasr, Math, SFU  On the covering number of graphs. 
Tue 04 Dec / 3:30 / EAA1100  Roded Sharan, Technion, Haifa  Incomplete Directed Perfect Phylogeny. 
Tue 11 Dec / 3:30 / EAA1100  Frederic Havet, CNRS, France  Design of fault tolerant onboard networks with priorities 
Tue 18 Dec / 3:30 / EAA1100  Mirka Miller, Newcastle, Australia  Eccentric Digraphs 
Summer 2001  
Thu 10 May / 3:30 / EAA1100  John Mighton, Fields Inst.  A New Reduction of Graph Theory and Binary Matroids 
Tue 15 May / 3:30 / EAA1100  Sergei Bespamyatnikh, CS, U. British Columbia  Graph of triangulations of convex polytopes in R^3 
Tue 26 Jun / 3:30 / K9509  Matt DeVos, Princeton U.  On Packing TJoins 
Tue 10 Jul / 3:30 / EAA1100  Moishe Rosenfeld, U. of Washington  Hamiltonian Decomposition of Prisms over cubic graphs 
Tue 17 Jul / 3:30 / K9509  Claude Tardif, U. of Regina  Fractional aspects of Hedetniemi's conjecture 
Spring 2001  
Tue 30 Jan / 3:30 / K9509  Reza Naserasr, Math, SFU  On $\Delta$critical graphs 
Wed 31 Jan / 2:30 / K9509  Brett Stevens, Math, SFU  Packing and covering designs 
Tue 06 Feb / 3:30 / K9509  Luis Goddyn, Math, SFU  Rangerestricted flows in regular matroids. 
Tue 13 Feb / 3:30 / EAA1100  Jarik Nesetril, Charles University, Prague  On a homomorphism duality for oriented trees. 
Tue 20 Feb / 2:30 / EAA1100  Valentine Kabanets, Inst. for Advanced Study  In search of an easy witness: Exponential time vs probabilistic polytime. 
Tue 20 Feb / 3:40 / EAA1100  Wayne Broughton, Okanagan University Coll.  Quasi3 Designs and Hadamard Matrices. 
Wed 28 Feb / 3:30 / K9509  Pavol Hell, SFU  List homomorphisms and partitions 
Tue 6 Mar / 3:30 / EAA1100  Steph Durocher, U. British Columbia  The tangled tale of the rectilinear crossing number of K_n 
Tue 13 Mar / 3:30 / EAA1100  Richard Anstee, U. British Columbia  Small Forbidden Configurations 
Tue 20 Mar / 3:30 / EAA1100  Brett Stevens, Math, SFU  Packing Arrays II: Beyond Codes, the Triumphant Return of Designs! 
Tue 27 Mar / 2:30 / EAA1100  Lou Ibarra, U. Victoria  Dynamic algorithms for chordal and interval graphs. 
Tue 27 Mar / 3:30 / EAA1100  Jonathan Jedwab, HewlettPackard Labs, Bristol  Combinatorial Design Theory in an Industrial Research Lab 
Wed 28 Mar / 2:30 / K9509  William Evans, U. British Columbia  Recovering lines with fixed linear probes 
Wed 28 Mar / 3:30 / K9509  Petr Lisonek, Math, SFU  Classification of Binary Linear Codes with Small Codimension 
Tue 3 Apr / 3:30 / EAA1100  Mateja Sajna, Capilano Coll.  Decomposition of complete graphs into cycles of a fixed length 
Wed 4 Apr / 3:30 / K9509  Veselin Jungic, Math, SFU  Diophantine Ramsey Theory and Recurrence in Dynamical Systems 
Tue 10 Apr / 3:30 / EAA1100  Ladislav Stacho, Math, SFU  Edge Disjoint Cycles Through Prescribed Vertices 
Tue 17 Apr / 3:30 / EAA1100  Nancy Neudauer, Pacific Lutheren U.  Bicircular Matroids and Transversal Presentations 