- January 12
Organization Meeting

- January 19
Ryan Jones:
From a Checkerboard Problem to an Edge Coloring Problem

- January 26
Kyle Kolasinski:
Moving Gracefully
Toward Graph Labelings

- February 2
David Richter:
How to Draw a Tait-Colored Graph

- February 16
Allan Bickle:
Application of Cores to Graph Coloring Problems

Abstract: The k-core of a graph is the maximal subgraph with minimum degree at least k. Cores have a very natural application to graph coloring. They can be used to prove the core number bound, an upper bound for chromatic number which is both sharp and easy to compute. Cores make possible simpler proofs of existing results including Brooks' Theorem and suggest extensions of some results. Time permitting, we will discuss the Nordhaus-Gaddum Theorem and using cores to determine which graphs achieve this upper bound.

- February 23
Allen Schwenk:
How many fours are needed?

Abstract: A well known problem challenges us to write an expression using four 4s to obtain each integer from 1 to 100. For example

1 = 44/44

2 = 4x4/(4+4)

3 = sqrt(4x4)-4/4

etc.

But do we really need as many as four 4s? We are allowed to use common mathematical operations that are represented with symbols, but not words or letters, +, ?, x, /, sqrt (but using the surd symbol), factorial, decimal point, etc. We must not use any other digits or letters.

What is the fewest number of 4s needed to represent every natural number? I'll bet it is less than four.

- March 16
Jianwei Lin:
Vertex Rainbow Colorings of Graphs

- March 23
Ping Zhang:
Sigma Colorings of Graphs

Gary Chartrand: Oriented Graphs

- March 30
Bryan Phinezy:
Local Metric Sets in Graphs

- April 6
Kyle Kolasinski:
Modular Edge-Graceful Graphs

Ryan Jones: Cents and Sensitivity

- April 13
Gary Chartrand:
Hamiltonicity

- April 13
Weston Mitchell :
Detour Distance in Graphs

Spring 2009

Fall 2008

Spring 2008

Fall 2007

Spring 2007

Fall 2006