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The Mathematical Association of America

North Central Section

Fall 2002 Meeting

October 25-26, 2002

Minnesota State University, Moorhead MN

Preliminary Program

Friday, October 25

7:00-8:00  Registration, Center for Business Atrium, $8.00 for members; students and first time attendees free

            7:00-8:00  MAA Book Sale, Center for Business 108

            8:00-9:00  Evening Session, Center for Business 109, Derald Rothmann presiding .
                                Invited Address:  Teaching with MATHEMATICA, Davis Cope, NDSU  

            9:00-???   Reception, Center for Business Atrium

Saturday, October 26

8:00-11:00  Registration, Center for Business Atrium

8:00-2:45  Book Sale, Center for Business 108

9:00-11:55  Morning Session, Tim Peil presiding        

9:00-9:05  Welcome, Vice President Bette Midgarden

9:10-9:30  “Cluster Analysis for Contours”, M.B. Rao, NDSU

Abstract:  A consulting problem from the Geosciences Department will be presented.  The basic question is how to form clusters of contours so that in each cluster the contours are more or less similar and contours belonging to different clusters are not alike.  We use Fourier Analysis to achieve the objective.

9:30-9:50  “One, Two, Three, Many:  Subitizing, Homomorphisms, and Cancellation”, Thomas Q. Sibley, St. John’s University

Abstract:  Cognitive psychologists have started to figure out how children get from “one, two, three, many” to fancier mathematics, such as the natural numbers.  However, homomorphisms provide a more mathematical way to link the natural numbers to childhood counting and other systems.  I’ll generalize this using the cancellation law:  if x+z = x+y, then x = y.

9:50-10:10  “Elliptic Functions as Trigonometry”, Bill Schwalm, UND  

Abstract:  Elementary properties of the Jacobi elliptic functions sn(x,k), cn(x,k) and dn(x,k) are developed as ratios using an ellipse, exactly as trig functions are developed using a reference circle.  Suggested homework includes the hyperbolic analogs sh(x,k), ch(x, k) and dh(x, k).

10:10-10:30  “The Semigroup of Quotients of a Semigroup S”, Eric Lund, Bemidji State University  

Abstract:  For a semigroup S with identity and with subsemigroup A, we define the right semigroup of fractions S[A^-1], and give necessary and sufficient conditions for this semigroup of fractions to exist.  The subsemigrouop M of regular elements in S is then defined, together with the semigroup of quotients, S[M^-1].

10:30-11:00  Break

11:00-11:55  Invited Address:  Attributable Risk Estimation:  A Tale of Mathematical/Statistical     Modeling, W. Michael O’Fallon, Mayo Clinic

12:00-12:50  Lunch, Comstock Memorial Union Comstock Room, $8.00 (email reservations to Don Mattson,, by October 22)

1:00-1:30  Business Meeting, M.B. Rao, President, presiding

1:30-2:10  Afternoon Session, M.B. Rao presiding

1:30-1:50  “Pertinent Porcine Probability Problems”, Marc Brodie, College of St. Benedict  

Abstract:  We will determine the probability of winning in some games in which a player must match an opponent’s success to avoid conceding a point.

1:50-2:10  “Distance and Area Measurement”, Wally Sizer, Minnesota State University Moorhead  

Abstract:  We will review some distance notions and see some analogous notions of area, concluding with the concept of an area metric.