DREI '98
Research Program Schedule
July 20 - 24, 1998


Monday Tuesday Wednesday Thursday Friday
7:30-8:00 shuttle shuttle shuttle shuttle shuttle
8:00-9:00 Breakfast Breakfast Breakfast Breakfast Breakfast
9:00-9:30 Introduction
Fred Roberts & Linda Lesniak


Cops,Robbers, and Dismantle Graphs
Peter Winkler 		On k-Ordered Graphs Jill Faudree Maximizing the number of certain subgraphs in various classes of graphs Owen Byer Can You Find a Second Hamiltonian Circuit in a Hamiltonian 3-Regular Graph? Enrique Moreno Open Problem Session
9:30-9:40 Break Break Break Break
9:40-10:00 On k-ordered Hamiltonicity in Bipartite Graphs Allison Wolf Combinatorial Card Tricks Hal Kierstead Hong-Jian Lai General properties of algebraically defined graphs Andrew Woldar
10:00-10:10
10:20-10:30 Vertex Disjoint Cycles in Star-Free Graphs Lisa Markus Extremal Problems for Forbidden Pairs that Imply Hamiltonicity Ralph Faudree Walks in Graphs XingXing Yu Applications of Some Families of Algebraically Defined Graphs Felix Lazebnik
10:30-10:50
10:50-11:00 Break Break Break Break Break
11:00-11:30 Long Cycles and the Cycle Space of a Graph
Steve Locke 		Coffee break Coffee break Coffee break Coffee break
11:30-11:40 Break LINK Software Jon Berry Plenary Session Ron Gould Plenary Session Brian Alspach A Single Way to solve All of the problems in Mathmematics Education Joe Rosenstein
11:40-12:10 The Cycle Space a 3-Connected Hamiltonian GraphMark Barovich
12:10-12:30 Break
12:30-1:30 Lunch Lunch Lunch Lunch Lunch
1:30-2:00 DIMACS Module Series
Steve Maurer 		Computer discussion Spanning Cycles in Dense Graphs Sarmad Abbasi Research discussion Research discussion
2:00-2:30 Uniquely Hamiltonian Graphs Bill Jackson Two-factors with few components in claw-free graph Mike Jacobson Cycles on Locally n-connected graphs Glenn Acree
2:10-2:30 On Colored Paths and Cycles Andras Gyarfas
2:30-2:40 Break Break Break Break
2:40-2:50 Long Paths: A Stroll Along Two Open Problems John Harris Planar Hamiltonian Chordal Graphs are Cycle Extendable Tao Jiang Connectivities and Paths Guantao Chen
2:50-3:00 Average Diameter and Its Estimation Zhizhang Shen
3:00-3:10
3:10-3:20 Break Break Break Break
3:20-4:00 Coffee break Coffee break Coffee break Coffee break Coffee break
4:00-4:30 On Circuit Semi-Isomorphism of Graphs Alex Kelmans Hamiltonian cycle, toughness, and chordal graphs Jeno Lehel Special Event: Professors who snooze and those who steal: an introduction to interval graphs and some generalizations Ann Trenk
4:30-5:00 shuttle Light subgraphs of polyhedral graphsHeinz-Juergen Voss Liar!
Joel Spencer 		shuttle
5:00-5:10 shuttle
5:10-5:30 shuttle
5:30-6:00 shuttle
6:00-6:30
6:30- Barbeque Dinner Dinner Dinner - Ethnic restaurant Dinner Dinner
8:00-9:00 Trees That Keep the Walls from Falling Down Ruth Haas Teacher Presentations




DREI '98 Program Schedule

July 27 - 31, 1998

Sunday , July 26 (AT THE WYNDHAM GARDEN HOTEL)
6:30-7:30 Dinner
7:30-8:30 Shortest Connecting Networks Henry Pollak

Monday Tuesday Wednesday Thursday Friday
7:30- shuttle shuttle shuttle shuttle shuttle
8:00-9:00 Breakfast Breakfast Breakfast Breakfast Breakfast
9:00-9:55 Introduction
Fred Roberts & Linda Lesniak


Plenary Session - Crossing Numbers Dan Archdeacon 		Flexibility of Embeddings of Graphs in Surfaces Bojan Mohar Trading Crossings for Handles and Crosscaps Dan Archdeacon Dirac's Conjecture Wolfgang Mader Group Representations and Graph Embeddings Jozef Siran,

Cayley Maps Tom Tucker,

Regular Maps with Arbitrarily Large Planar Width Roman Nedela
10:00-10:05 Break New Bounds on Crossing Numbers
Geza Toth 		Break
10:05-10:30 Bounded Flexibilility of Polyhedral Embeddings on a Surface Neil Robertson Some Applications of the Robertson - Seymour Clique - Minor Exclusion Theorem
Bruce Reed
10:30-11:00 Coffee break Crossing Numbers
Gelasio Salazar
11:00-11:30 Graph Planarity Alexander Kelmans Coffee break Coffee break Coffee break Coffee break
11:30-12:00 Tom Sawyer Software for Graphical Visualizations Therese Biedl
Plenary Session
Pedagogy Panel 		Graph Coloring Related to Knots and Links
Louis Kauffman 		Trees and Euler Tours in Planar Graphs and Its Relatives
Bruce Richter
12:00-12:30 On the Maximum Planar Subgraph Problem
Gruia Calinescu
12:30-1:30 Lunch Lunch Lunch Lunch Lunch
1:30-2:00 DIMACS Educational Module SeriesStephen Maurer Quadrangulations of Closed Surfaces
Atsuhiro Nakamoto 		Loose Ends in Knot Theory (The Computational Complexity of Uknotting)
Jeff Lagarias 		Virtual Knot Theory Louis Kauffman Caley Snarks and Regular Maps on Surfaces Martin Skoviera
2:00-2:05 Pfaffian Orientations and Drawing of Cubes MartinLoebl Break Break
2:05-2:15 Diagonal Flips in Pseudo - Triangulations on Closed Surfaces Seiya Negami The Classification of Planar Groups Tom Tucker
2:15-2:30 Break
2:30-2:35 A characterization
of those topologically - minor - minimal graphs of crossing number at least 2 which have no V _ 8 minor Bogdan Oporowski 		Intercalate Matroids
Isidoro Gitler
2:35-2:40
2:40-2:50 Reconstructing Graphs Embedded in Surfaces Yue Zhao
2:55-3:15 K4, $-e Has no finite planar cover Peter Hlineny A Whitney 2-Isomorphism theorem for hypergraphs Dirk Vertigan The 1, 2, Infinity Conjecture for Embedding Covering Spaces of Finite Graphs Henry Glover
3:15-3:30 Defective Coloring of Graphs on Surfaces Lenore Cowen
3:30-4:00 Coffee break Coffee break Coffee break Coffee break Coffee break
4:00-4:30 Vertex Accumulation Points in Infinite Planar Graphs R. Bruce Richter Light subgraphs of multigraphs embedded in compact 2-Manifolds Heinz-Juergen Voss The Geometry of Fullerness Joeseph Malkevitch A Splitter Theorem for Internally Four-Connected Graphs
Thor Johnson 		FREE TIME
4:30-4:40 Surfaces and connectivities Xiaoya Zha Combinatorics of Vassiliev Invariants in Relation to Functional Integration Louis Kauffman
4:40-5:00 A Characterization
of Weakly
Bipartite Graphs Bertrand Guenin
5:00-5:05 A Short proof of the excluded grid theorem Reinhard Diestel Digraph Minors Paul Seymour
5:05-5:30 Triangular imbeddings of $G_{(m)}$
Andre Bouchet
5:30-5:45 Between Planarity And Flatness Hein van der Holst
5:45-6:00 The looseness of triangulations on closed surfaces Takayuki Tanuma
6:00-6:30 Shuttle Shuttle Shuttle Shuttle
7:00-8:00 Barbeque Dinner -At Hotel Dinner -At Hotel Dinner -At Hotel Dinner -At Hotel
8:00-9:00 Teacher Presentations - optional Free Time Free Time



DREI '98 Program Schedule

August 3 - 7, 1998

Sunday (AT THE WYNDHAM GARDEN HOTEL)
1:00-2:00 Flows, Discrepancy, and reorientations Luis Goddyn
2:00-3:00 Flows, coloring and 19th centery invariant theory Mike Tarsi
3:00-4:00 Coffee
4:00-4:40 Reducible configurations for the CDC-conjecture Andreas Huck
4:45-5:25 Contracting bonds Sean McGuinness & Jan Van den Heuvel
5:30-6:10 Hamiltonian weights and critically non-faithful coverage graphs C Q Zhang


Monday Tuesday Wednesday Thursday Friday
7:30- shuttle shuttle shuttle shuttle shuttle
8:00-9:00 Breakfast Breakfast Breakfast Breakfast Breakfast
9:00-9:45 Introduction Fred Roberts and Linda Lesniak
The four-colour theorem Plenary Session - Paul Seymor 		Circular chromatic number of a graph Xuding Zhu Problems related to graph colorings Zsolt Tuza Color spaces and minors Tommy Jensen The choice number of random bipartite graphs Michael Krivelevich
9:45-10:00 Break Break Break Break
10:00-10:20 Superposition and constructions of graphs without nowhere-zero k-flows Martin Kochol Coloring of mixed hypergraphs: results and open problems Vitaly Voloshin Coloring and Independence Ratio of Circulants Marcello Carvalho Jeff Kahn
10:20-10:30
10:30-11:00 Coffee Break
11:00-11:30 4-colouring even triangulations Joan Hutchinson Coffee Break Coffee Break Coffee Break Coffee break
11:30-12:00 REU Presentations Best Teacher Implementation Session Plenary: The radio channel assignment problem Dominic Welsh Plenary: Timetables, factors and colorings Bjarne Toft
12:00-12:30 3-colouring graphs on the Klein bottle Barrett Walls
12:30-1:30 Lunch Lunch Lunch Lunch Lunch
1:30-2:00 Plenary - Steve Maurer Break Break Break Break
2:00-2:10 Graph Colouring Via the Probabilitic Method Bruce Reed Coloring edges of graphs embedded in surfaces Yue Zhao Upper chromatic number in Steiner systems Lorenzo Milazzo Coloring and Independence Ratio of Circulants Karen Collins List Partitions Pavol Hell
2:20-2:25
2:25-2:30
2:30-2:40 Meaurements of Uncolorability Mark Goldeberg Coloring the maximal cliques of a graph Sylvain Gravier Covering designs and domination in Knesser graphs Douglas West
2:40-2:45
2:45-3:00 Tutte's edge 3-Coloring conjecture Robin Thomas
3:00-3:15 Flows and Antiflows, Colorings and Strong Colorings of Oriented Graphs Andre Raspaud Uniquely 4-Colourable Planar Graphs Tom Fowler Co-Coloring Graphs of Fixed Genus John Gimbel Varations on the classical Ramsey problem Dhruv Mubayi
3:15-3:30
3:30-4:00 Coffee break Coffee break Coffee break Coffee break Break
4:00-4:30 Non-Abelian Flows Matthew Devos Independent sets in cubic planar graphs Christopher Heckman Plenary Peter Winkler Uniquely colorable perfect graphs Gabor Bacso
4:30-5:00 Extending Graph Colorings Mike Albertson Flows and Antiflows, Colorings and Strong Colorings of Oriented Graphs Jarek Nesetril ON (a,w)--GRAPHS Alexander Kelmans
5:00-5:10 Problem session
5:10-5:30 Break Break
5:30-6:00 Shuttle Shuttle Shuttle
6:30 Barbeque Dinner Dinner Dinner - Ethnic restaurant Dinner
8:00 - 9:00 Ramsey Theory Nancy Eaton Teacher Presentations