2016 |
The Ever-Changing World of Ramsey Numbers MIGHTY LVII, Wright State Univeristy, Dayton Ohio |

2015 |
Hamilton and Hamiltonian Graphs COLLEGE OF CHARLESTON, Charleston, South Carolina. From Connectivity to Coloring The 29th MIDWEST CONFERENCE ON COMBINATORICS, CRYPTOGRAPHY AND COMPUTING, College of Charleston, South Carolina. Hamiltonian Extension ANNUAL MEETING OF AMERICAN MATHEMATICAL SOCIETY, San Antonio, TX |

2014 |
A Graph Theoretic Division Algorithm ANNUAL MEETING OF AMERICAN MATHEMATICAL SOCIETY, Baltimore, MD. On the Eulerian Cycle Decomposition Conjecture ANNUAL MEETING OF AMERICAN MATHEMATICAL SOCIETY, Baltimore, MD. On Hamiltonian Graphs MIGHTY LV, University of Detroit Mercy, MI |

2013 |
Eulerian Graphs and a Cycle Decomposition Conjecture The Yousef Alavi Memorial Symposium Western Michigan University, Kalamazoo, MI On Cycle Decompositions of Eulerian Graphs The 27th MIDWEST CONFERENCE ON COMBINATORICS, CRYPTOGRAPHY AND COMPUTING, Southwestern University, Georgetown, TX Hamiltonian Walks in Graphs ANNUAL MEETING OF AMERICAN MATHEMATICAL SOCIETY, San Diego, CA. |

2012 |
Powers of Strong Digraphs ANNUAL MEETING OF AMERICAN MATHEMATICAL SOCIETY, Boston, MA. Modular and Graceful Colorings FORTY-SECOND SOUTHEASTERN INTERNATIONAL CONFERENCE ON COMBINATORICS,GRAPH THEORY AND COMPUTING, Boca Raton, FL The early years of what became graph theory CALVIN COLLEGE, Grand Rapids, MI A graph coloring view of some combinatorial problems TWENTY-SIXTH MIDWEST CONFERENCE ON COMBINATORICS, CRYPTOGRAPHY AND COMPUTING, Southern Utah University, Cedar City, UT |

2011 |
Two theorems on four colorings ANNUAL MEETING OF AMERICAN MATHEMATICAL SOCIETY, New Orleans, LA. On four colorings in graphs FORTY-SECOND SOUTHEASTERN INTERNATIONAL CONFERENCE ON COMBINATORICS,GRAPH THEORY AND COMPUTING, Boca Raton, FL Reflections on colorings GRAND VALLEY STATE UNIVERSITY, Allendale, MI Graph Theory -- 275 Years and Counting THE MICHIGAN MAA & MichMATYC, WMU, Kalamazoo, MI |

2010 |
Graph colorings that are sum colorings FORTY-FIRST SOUTHEASTERN INTERNATIONAL CONFERENCE ON COMBINATORICS,GRAPH THEORY AND COMPUTING, Boca Raton, FL Reflections on colorings MIGHTY XLIX, University of Detroit Mercy, MI |

2009 |
From checkerboards to graph colorings FORTIETH SOUTHEASTERN INTERNATIONAL CONFERENCE ON COMBINATORICS,GRAPH THEORY AND COMPUTING, Boca Raton, FL Reflections on colorings TEXAS A\& M UNIVERSITY at Galveston, TX. Rainbow connectivities of graphs TWENTY-THIRD MIDWEST CONFERENCE ON COMBINATORICS CRYPTOGRAPHY, AND COMPUTING, Rochester, NY. |

2008 |
Hamiltonian colorings of graphs THIRTY-NINTH SOUTHEASTERN INTERNATIONAL CONFERENCE ON COMBINATORICS,GRAPH THEORY AND COMPUTING, Boca Raton, FL Rainbow connectivities of graphs CENTRAL SECTION OF THE AMS ANNUAL MEETING, Kalamazoo, MI. Hamiltonian labelings of graphs TWENTY-SECOND MIDWEST CONFERENCE ON COMBINATORICS CRYPTOGRAPHY, AND COMPUTING, Las Vegas, LV. |

2007 |
From edge coloring to vertex coloring THIRTY-EIGHTH SOUTHEASTERN INTERNATIONAL CONFERENCE ON COMBINATORICS,GRAPH THEORY AND COMPUTING, Boca Raton, FL Radio colorings of graphs PEKING UNIVERSITY, Beijing, P. R. China From a banquet seating problem to a
graph coloring problem YAN TAI UNIVERSITY, Yan Tai, P. R. China |

2006 |
On Hamiltonian Walks in Graphs ANNUAL MEETING OF THE AMERICAN MATHEMATICAL SOCIETY, San Antonio, TX. Detectable colorings of graphs SRINAKHARINWIROT UNIVERSITY, Bangkok, Thailand Irregular colorings of graphs PEKING UNIVERSITY, Beijing, P. R. China Distance in graphs TSINGHUA UNIVERSITY, Beijing, P. R. China |

2005 |
Detectable colorings of graphs THIRTY-SIXTH SOUTHEASTERN INTERNATIONAL CONFERENCE ON COMBINATORICS,GRAPH THEORY AND COMPUTING, Boca Raton, FL Domination and stratification in graphs FUJIAN NORMAL UNIVERSITY, Fujian, P. R. China Distance in graphs - Taking the long view FUZHOU UNIVERSITY, Fuzhou, P. R. China |

2004 |
Homogeneous embeddings and stratified graphs ANNUAL MEETING OF THE AMERICAN MATHEMATICAL SOCIETY, Phoenix, AZ Hamiltonian colorings of graphs THIRTY-FIFTH SOUTHEASTERN INTERNATIONAL CONFERENCE ON COMBINATORICS,GRAPH THEORY AND COMPUTING, Boca Raton, FL On gamma-labelings of graphs MIGHTY XXXVIII, Western Kentucky University |

2003 |
Local Colorings of Graphs THIRTY-FOURTH SOUTHEASTERN INTERNATIONAL CONFERENCE ON COMBINATORICS,GRAPH THEORY AND COMPUTING, Boca Raton, FL Homogeneous embeddings and stratified graphs MIGHTY XXXVII, Valparaiso University at Valparaiso, IN |

2002 |
Distance-Defined Subgraphs of a Graph THIRTY-THIRD SOUTHEASTERN INTERNATIONAL CONFERENCE ON COMBINATORICS,GRAPH THEORY AND COMPUTING, Boca Raton, FL |

2001 |
Full domination in graphs THIRTY-SECOND SOUTHEASTERN INTERNATIONAL CONFERENCE ON COMBINATORICS,GRAPH THEORY AND COMPUTING, Baton Rouge, LA Divisor graphs MICHIGAN SECTION OF THE MAA ANNUAL MEETING, Hope College, MI. |

2000 |
On the planarity of iterated jump graphs FIFTEENTH CLEMSON MINI CONFERENCE, Clemson University, Clemson, SC. Radio labelings of graphs NINTH QUADRENNIAL INTERNATIONAL CONFERENCE ON GRAPH THEORY, COMBINATORICS, ALGORITHMS, AND APPLICATIONS Western Michigan University, Kalamazoo, MI. Don't touch that dial! MICHIGAN SECTION OF THE MAA ANNUAL MEETING, Central Michigan University, MI. On the metric dimension of a graph THIRTY-FIRST SOUTHEASTERN INTERNATIONAL CONFERENCE ON COMBINATORICS,GRAPH THEORY AND COMPUTING, Boca Raton, FL. Full domination in graphs ANNUAL MEETING OF THE AMERICAN MATHEMATICAL SOCIETY, Special Session on Graph Theory, Washington, DC |

1999 |
Stratification and domination in graphs MIGHTY XXXII, Indiana-Purdue University at Fort Wayne, MI. Convexity in Graphs MICHIGAN SECTION OF THE AMS ANNUAL MEETING, Eastern Michigan University, MI. How large can the domination numbers of a graph be? MIGHTY XXXI, Oakland University, MI. The Steiner number and Steiner sets in graphs THIRTIETH SOUTHEASTERN INTERNATIONAL CONFERENCE ON COMBINATORICS,GRAPH THEORY AND COMPUTING, Boca Raton, FL. |

1998 |
On the planarity of jump graphs MIGHTY XXX, Ball Sate University, IN. Geodetic graphs and geodetic numbers in graphs WINNIPEG COMBINATORICS MATHEMATICS CONFERENCE University of Winnipeg, Winnipeg, CANADA Graph representations by means of partitions and
distance TWENTY-NINTH SOUTHEASTERN INTERNATIONAL CONFERENCE ON COMBINATORICS,GRAPH THEORY AND COMPUTING, Boca Raton, FL. |

1997 |
Arithmetic properties of generalized Euler numbers ANNUAL MEETING OF THE AMERICAN MATHEMATICAL SOCIETY, San Diego, CA. Truncated Boolean algebras as subspace arrangementsTWENTY-EIGHTH SOUTHEASTERN INTERNATIONAL CONFERENCE ON COMBINATORICS,GRAPH THEORY AND COMPUTING, Boca Raton, FL. The characteristic polynomials of interpolations between
Coxexter arrangements CENTRAL SECTIONAL MEETING OF THE AMERICAN MATHEMATICAL SOCIETY, Special Session on Algebraic Combinatorics Wayne State University, Detroit, MI. Starfree biclique decompositions of complete graphs MIGHTY XXVII, University of Wisconsin, Oshkosh, WI Subspace arrangements and signed graphs THE FIRST CONFERENCE OF YOUNG CHINESE MATHEMATICIANS IN NORTH AMERICA University of California at Berkeley, Berkeley, CA. The geodetic number of a graph MIGHTY XXVIII, Eastern Michigan University, MI. |

1996 |
Signed graphs and subspace arrangements WESTERN MICHIGAN UNIVERSITY, Kalamazoo, MI. The Wiener polynomial of a graph EIGHTH QUADRENNIAL INTERNATIONAL CONFERENCE ON GRAPH THEORY, COMBINATORICS, ALGORITHMS, AND APPLICATIONS Western Michigan University, Kalamazoo, MI. |

1995 |
Subposets of Boolean algebras UNIVERSITY of MICHIGAN, Ann Arbor, MI The A, B and C in hyperplane arrangements UNIVERSITY OF TEXAS AT EL PASO, El Paso, TX. |

1994 |
The characteristic polynomials of hyperplane arrangements INTERNATIONAL CONFERENCE ON ARRANGEMENTS OF HYPERPLANES Marseilles, FRANCE. Signed graphs MIGHTY XXIII, Kalamazoo, MI Subposets of Boolean algebras MICHIGAN STATE UNIVERSITY, Lansing, MI |