Combinatorial Potlatch
University of Puget Sound
Saturday, February 16, 2002

Definitions | Speakers | Schedule | Abstracts | Registration | Getting There | Lodging | Eating | Conference Party | History | Contacts

The n-th Annual Combinatorial Potlatch will be held February 16, 2002 on the campus of the University of Puget Sound in Tacoma, Washington.


Combinatorial Potlatches have been held for many years at various locations around Puget Sound and southern British Columbia, and are an opportunity for combinatorialists in the region to gather informally for a day of invited talks and conversation. While most who attend work in, or near, the Puget Sound basin, all are welcome.

The American Heritage Dictionary defines "potlatch" as: A ceremonial feast among certain Native American peoples of the northwest Pacific coast, as in celebration of a marriage or an accession, at which the host distributes gifts according to each guest's rank or status. Between rival groups the potlatch could involve extravagant or competitive giving and destruction by the host of valued items as a display of superior wealth. [Chinook Jargon, from Nootka p'achitl, to make a potlatch gift.]

Invited Speakers

  • Brian Alspach, University of Regina and Simon Fraser University (Emeritus)
    Title: Group Actions and Hamilton Decompositions of Complete Graphs
  • Brett Stevens, Carleton University (Ottawa)
    Title: On Universal Cycles of k-sets of an n-set
  • Jonathan Jedwab, Simon Fraser University
    Title: Combinatorial Design Theory and the IEEE 802.12 Transmission Code

  • Abstracts

  • Group Actions and Hamilton Decompositions of Complete Graphs
    Brian Alspach, University of Regina and Simon Fraser University (Emeritus)

    Abstract: We shall take a look at the problem of determining for which values of n there exist Hamilton decompositions of the complete graph of order n which are invariant under the action of cyclic groups. We shall also consider some extensions of this problem. In summary, not a lot is known.

  • On Universal Cycles of k-sets of an n-set
    Brett Stevens, Carleton University (Ottawa)

    Abstract: In 1992 Chung, Diaconis and Graham wrote the readable and thoroughly enjoyable "Universal Cycles for Combinatorial Structures". In it they generalize both the definition and construction of de Bruijn cycles to other families of combinatorial objects: permutations, partitions and subset systems. These generalizations resonate with generalizations of Gray Code, being gray codes that are compatible with queue data structures. Hurlbert and Jackson have continued this work solving, among other families, universal cycles for $k$-sets of $n$-sets for $k=2, 36$ and partially for other $k$. In their empirical work it was noted and conjectured that a universal cycle for the $n-2$-sets of an $n$-set never exists, even thought the standard necessary conditions are satisfied for all odd $n$. This was recently proved by Stevens, et al. This talk will review the past work, this recent result and the future look at Gray codes or de Bruijn generalizations compatible with different data structures.

  • Title: Combinatorial Design Theory and the IEEE 802.12 Transmission Code
    Jonathan Jedwab, Simon Fraser University

    Abstract: TBA

  • Schedule

  • 10:00-10:30 Registration, Coffee and Doughnuts
  • 10:30-11:30 Brian Alspach, Group Actions and Hamilton Decompositions of Complete Graphs
  • 11:30-1:30 Lunch, Engine House #9, 611 N. Pine Street, 253-272-3435
  • 1:30-2:30 Brett Stevens, On Universal Cycles of k-sets of an n-set
  • 2:30-3:00 Break, Coffee and Cookies
  • 3:00-4:00 Jonathan Jedwab, Combinatorial Design Theory and the IEEE 802.12 Transmission Code
  • 5:00-7:00 Dinner, Harmon Brewery
  • 7:00-???? Conference Party at Coles Tavern, A Blues Oasis

  • Registration

    Please help us plan food for break services by carefully considering the following (punitive) registration options.

  • Advance registration: Free. Contact Nancy Neudauer <> with your probability of attending, hopefully at least a few days in advance. To receive more announcements, or for future Combinatorial Potlatches, send a request to Rob Beezer <> to be added to the announcement list.
  • On-site registration: $100 per person.

  • Getting There (Location and Driving Directions)

    All talks and breaks will be conducted in the Murray Boardroom, which is located on the first floor of the Wheelock Student Center in the northeast corner. The Wheelock Student Center is building number 20 on the campus map. A larger map of the Tacoma area works well with written directions describing travel by car, plane, train or bus. Parking on the weekend should not present any special problems, and no parking passes are necessary. Approaching the Student Center from the south along Lawrence Street (off N 11th Street) will lead to a large parking lot adjacent to the building. Or find the parking lot just west of the intersection of N 14th and Alder.

    Local Lodging

    For those traveling from some distance the UPS web site has some suggestions for overnight accomodations, bed and breakfasts and hotels and motels. Keenan House is the closest bed and breakfast at just a few blocks from campus. If you are combining business with pleasure, The Villa is pretty deluxe, but has also been eager to accomodate visitors to the university at their lowest rates for some of the fancier rooms.

    For more traditional hotels and motels, we can recommend The Tacoma Sheraton, though it is likely the most expensive of the lot. Some of the hotels listed on the UPS site as being "off I-5" can be pretty ordinary. If you are coming down through the Olympic Peninsula, The Inn at Gig Harbor is a nice location 15 minutes short of campus, while the Maritime Inn is a small hotel right on the waterfront in Gig Harbor proper - very picturesque.

    Local Eateries

    Some suggestions for lunch or dinner that are nearby are provided by the UPS web site. Or consult this list, which seems to have it about right, or the Tacoma Weekly's more comprehensive list. The Engine House #9 might be a good location for a group lunch - close to campus, variants on pub food, and a wide selection of beer, some brewed next door. More scenic is Katie Downs with good pizza and good beer right on the waterfront along Ruston Way. Gateway to India is close by, and caters to vegetarians (more info on a couple of the lists referenced above).

    Conference Party

    A no-host conference party will be held after dinner at Coles Tavern, A Blues Oasis located at 5811 N 51st St, which is close to the entrance to Pt Defiance Park at the northern tip of North Tacoma (though this is really the very small town of Ruston). Phone number there is 253-879-1119.


    A history of the Combinatorial Potlatch is available.
    Photos of the speakers in action are also available.


    Program Committee: Nancy Neudauer <>

    Local Arrangements Committee: Rob Beezer <>

    UPS Math/CS Department

    Last Updated: February 18, 2002