Discrete Math Seminar Archive of Talks

Department of Mathematics
University of Nebraska-Lincoln

Meeting Time: Tuesdays 2:00-2:50pm in 351 Avery Hall

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Fall 2011

Seminar Coordinator: Katie Johnson

Aug 23: Organizational Meeting
Aug 30: Jamie Radcliffe, Extremal Independent Sets (abstract)
Sep 6: Katie Johnson, The Technique of "Focusing'' in Ramsey Theory (abstract)
Sep 13: Derek Boeckner, Ramsey Theory Continued (abstract)
Sep 20: Jeonghan Ko, UNL Engineering, An Application of Mixed Integer Programming in Industrial Engineering: Module-Centric Approach to Integrated Adaptation of Assembly Products and Supply Chains (abstract)
Sep 27: Jason Smith, Iowa State University, Induced Saturation Number (abstract)
Oct 4: Zach Roth, Channel Polarization (abstract)
Oct 11: No Seminar - moved to Thursday. (Sectional meeting this weekend)
Oct 13: Special Seminar - Thursday, Oldfather 205, 2:30-3:30pm, Neal Bushaw, University of Memphis, Turán numbers of Multiple Paths and Equibipartite Trees (abstract)
Oct 18: No Seminar. (Fall break)
Oct 25: Sarah Behrens, Compressions and Isoperimetric Inequalities (abstract)
Nov 1: Lauren Keough, Maximizing Matchings in Threshold Graphs (abstract)
Nov 8: Derrick Stolee, Even More Generalizations of van der Waerden (abstract)
Nov 15: James Carraher, Mr. Paint and Mrs. Correct a Marker/Remover Game (abstract)
Nov 22: No Seminar. (Thanksgiving break)
Nov 29: Stephen Hartke, An entropy compression approach to nonrepetitive sequences (abstract)
Dec 6: Marcelo Firer, Universidade Estadual de Campinas (UNICAMP), Coding in the presence of semantic value of information (abstract)

Spring 2011

Seminar Coordinator: Katie Johnson

Jan 11: No Seminar.
Jan 18: Tyler Seacrest, Degree Sequences, Bisections, and Edge-Disjoint 1-factors (abstract)
Jan 25: No Seminar (special talk on Thursday instead).
Jan 27: (Note: this is a Thursday and the talk will be in Oldfather 207 from 2-2:50pm) Fan Chung, University of California, San Diego, Flipping edges and vertices in graphs (abstract)
Feb 1: Adam Azzam, Game Theory and School Choice (abstract)
Feb 8: Mike Ferrara, University of Colorado, Denver, Saturation numbers for Families of Ramsey-Minimal Graphs (abstract)
Feb 15: Jamie Radcliffe, Enumeration problems for homomorphisms (abstract)
Feb 22: Katie Johnson, The Linear Algebra Method (abstract)
Mar 1: No Seminar.
Mar 8: Brendon Stanton, Iowa State University, Vertex Identifying Codes (abstract)
Mar 15: Derek Boeckner, Limits of Dense Graph Sequences (abstract)
Mar 22: No Seminar (Spring Break)
Mar 29: Stephen Hartke, Brooks' Theorem from the Alon--Tarsi Theorem (abstract)
Apr 5: Katie Johnson, The Magic of Universal Cycles (abstract)
Apr 12: (Special Place: Avery 347) Andrew Ray, Extremal Trees and Reconstruction (abstract)
Apr 19: (Special Place: Avery 347) Tyler Seacrest, Packings and Realizations of Degree Sequences with Specified Substructures (abstract)
Apr 26: Jay Cummings, Invariants of Replacement Product Graphs (abstract)

Fall 2010

Seminar Coordinator: Christine Kelley

Aug 24: No Seminar.
Aug 31: Ryan Martin, Iowa State, Recent results on the edit distance of graphs. (abstract)
Sept 7: Derrick Stolee, The Lovasz Cathedral Theorem and Applications (abstract)
Sept 14: Tyler Seacrest, A circuitous proof of the Erdos-Gallai Theorem (abstract)
Sept 21: Zach Roth, Public-key cryptography using error-correcting codes, (abstract)
Sept 28: No Seminar.
Oct 5: Kenneth Monks, Colorado State University, The Odd Partition Poset and Moebius Numbers.(abstract)
Oct 12: Andrew Ray, Reconstructing Trees from their Wiener Matrix or Subtree Matrix.(abstract)
Oct 19: No Seminar, Fall Break.
Oct 26: Josh Laison, Willamette University, Obstacle Numbers of Graphs (abstract).
Nov 2: James Sellers, Penn. State University, Enumeration of the degree sequences of non-separable graphs and connected graphs. (abstract)
Nov 9: No Seminar (Math Day)
Nov 16: Rebecca Swanson, Nebraska Wesleyan University, Coloring Complexes (abstract).
Nov 23: Derrick Stolee, The Lovasz Two Ear Theorem and the Enumeration of 1-Extendable Graphs (abstract)
Nov 30: (NOTE: Room 19, Avery Hall) Joerg Kliewer, New Mexico State University, Coding Strategies for the Wiretap Channel and for Secure Network Coding (abstract).
Dec 7: Adam Azzam, TBA.

Spring 2010

Seminar Coordinator: Christine Kelley

Jan 12: No Seminar
Jan 19: Oliver Collins, University of Notre Dame, Continuous waveforms from binary signals
Jan 26: No Seminar
Feb 2: Christine Kelley , Coding for the wiretap channel
Feb 9: Tyler Seacrest , More on coding for the wiretap channel
Feb 16: Derrick Stolee , Topics in Graph Automorphisms (abstract)
Feb 23: Andrew Ray , Computing the Characteristic Polynomial of Graphs (abstract)
Mar 2: Kathryn Haymaker , Perfect codes in the Lee metric (abstract)
Mar 9: Michael Barrus, Black Hills State University, South Dakota, Substitution closures of the split graphs and matrogenic graphs (abstract)
Friday Mar 12: Derrick Stolee , Proposal Defense, Symmetric Optimization , (abstract) , 10:30-11:10 am, Avery 347 (Note special day and time)
Mar 16: No Seminar (Spring Break)
Monday Mar 22: Deanna Dreher , PhD defense. Pseudocodewords on Graph Covers and Computation Trees , 3:00 pm, Avery 351 (Note special day and time)
Mar 30: Nathan Axvig and Katie Morrison . Two short talks: "The Generalized Omura Decoder" by Nathan Axvig and "Towards a Duality Theory of Subspace Codes for Network Coding" by Katie Morrison
Monday Apr 5, 2:35 pm, Avery 351: Jeremy Martin, University of Kansas, Graph Varieties (abstract) (Note special time and day)
Apr 13: Cancelled so that people can attend Anthony DeLegge's dissertation defense. 1:30-3pm in 304 Oldfather Hall, "Mathematical Modeling of Optimal Seasonal Reproduction Strategies of Plant Populations and a Comparison of Long-Term Viabilities of Annuals and Perennials"
Apr 20: John Orr , The PageRank Algorithm and Web Search Engines (abstract)
Apr 27: Vinod Variyam , Green's Theorem and Isolation in Planar Graphs (abstract)

Fall 2009

Seminar Coordinator: Christine Kelley

Aug 25: Christine Kelley, Organizational meeting/ a graph-theoretic approach to designing hash functions (abstract)
Sept 1: Tyler Seacrest, A packing problem and a potential packing problem (abstract)
Sept 8: Stephen Hartke, Packings of degree sequences (abstract)
Sept 15: Katie Johnson, Counting Lower Hessenberg Matrices (abstract)
Sept 22: Andrew Ray, Festoon Trees (abstract)
Sept 29: Katie Morrison, Error-correction coding for an operator channel: Combinatorial bounds on the trade-off between the size of these codes and their minimum distance (abstract)
Oct 6: Katie Morrison, Error-correction coding for an operator channel (Part II): Combinatorial bounds on the trade-off between the size of these codes and their minimum distance (abstract)
Oct 13: Jamie Radcliffe, Extremal graphs for the number of k-colourings (abstract)
Oct 20: Fall break, no seminar.
Oct 27: No seminar.
Nov 3: Carina Curto, Geometry of stable cliques in neural networks (abstract)
Nov 10: Stephen Hartke, The Gallai-Edmonds theorem (abstract)
Nov 17: Judy Walker, Codes on Graphs: Shannon's Challenge and Beyond (abstract).
Nov 24: No seminar.
Dec 1: Jamie Radcliffe
Dec 8: Pascal Vontobel, Hewlett-Packard, Connections between the edge zeta function of a graph, counting in graph covers, and message-passing iterative decoding (abstract).

Spring 2009

Seminar Coordinator: Stephen Hartke

Jan 13: Stephen Hartke, Fisher's proof for tournaments of Seymour's 2nd neighborhood conjecture (abstract)
Jan 20: Jamie Radcliffe, Threshold graphs and the Grone-Merris conjecture (abstract)
Jan 27: Derrick Stolee, Log-space algorithm for reachability problem in planar DAGs with few sources (abstract)
Feb 3: Derrick Stolee, part 2
Feb 10: Andrew Ray, an introduction to algebraic graph theory (abstract)
Feb 17: Stephen Hartke, interlacing of eigenvalues for subgraphs
Feb 24: Christine Kelley, the spectral gap and expander graphs
Mar 3: Brenda Mammenga, Disjunctive and Selectivity Rado Numbers (abstract)
Fri Mar 13 at 2:30pm in 109 Avery: John Konvalina, Boolean Networks, Combinatorics, and the Fractal Nature of Life (abstract)
Mar 17: No seminar, spring break.
Mar 24: Travis Johnston, sorting signed permutations with cut-and-paste operations (abstract)
Mar 31: Jamie Radcliffe, the sign of a permutation of a multiset
Apr 7: Justin DeVries, the chromatic polynomial via homology (abstract)
Apr 14: Nate Axvig, an introduction to matroids
Apr 21: Cancelled so people may attend Duane Einfeld's thesis defense
Apr 28: Nate Axvig, an introduction to matroids, part 2: greedy algorithm and the matroid intersection theorem

Fall 2008

Seminar Coordinator: Stephen Hartke

Aug 26: Organization; Stephen Hartke, Two short beautiful proofs: the number of degree sequences of forests on n vertices and extending perfect matchings in the hypercube to hamiltonian cycles.
Sept 2: Christine Kelley, the Hirsch conjecture and 0/1 polytopes (abstract)
Sept 9: Stephen Hartke, the second short beautiful proof: extending perfect matchings in the hypercube to hamiltonian cycles.
Sept 16: Brian Kell, partial cubes
Sept 23: Brian Kell, partial cubes, continued.
Sept 30: Nate Axvig, Some Aspects of Cycle Codes. (abstract)
Fri Oct 3: Mike Ferrara will be speaking in the colloquium about Some Problems on Graph Subdivisions. (abstract)
Oct 7: Nate Axvig, cycle codes, continued.
Oct 14: Katie Morrison, an introduction to network coding. (abstract)
Oct 21: Fall break, no seminar.
Oct 28: Katie Morrison, network coding, continued.
Nov 4: Jamie Radcliffe, Entropy methods for estimating the number of perfect matchings in graphs. (abstract)
Nov 11: Stephen Hartke, counting perfect matchings in planar graphs.
Nov 18: Derek Boeckner, higher correlation inequalities. (abstract)
Nov 25: Abby Brackins, derivation of the uncertainty function. (abstract)
Dec 2: Katie Haymaker, On optimal instantaneous codes: A look at Huffman coding. (abstract)
Fri Dec 5: Christine Kelley will be speaking in the colloquium about algebraic constructions of codes using voltage graphs. (abstract)
Dec 9: Cancelled.

This page last modified January 19, 2012.