President Ohle congratulates Carolyn Dobler

Gustavus President Jack Ohle presented Professor Carolyn Dobler, Chair of the Mathematics and Computer Science Department, with the Faculty Service Award at today’s Founders Day ceremony in chapel.

I have long been interested in the parallels between “continuous” calculus and discrete calculus.  Finite difference formulas look a lot like familiar derivative formulas–with the right tweaking and summation formulas likewise resemble familiar integration formulas. Furthermore, Newton’s interpolating formula based on higher differences can be seen as analogs of Taylor’s polynomial.  In this seminar I shall present a survey of these parallels and others.  Also I’ll present a result I think is new: a discrete analog of Gronwall’s Lemma, a useful result in the theory of differential equations.  The discrete version then has implications in the theory of finite difference equations.

Pizza & beverage will be served.

The goal of the project is to reconstruct three-dimensional shape of placentas, and provide shape characterization for exploring the relation between placental shapes and fetal growth. We investigate two types of surface reconstruction methods: implicit and explicit methods.  Our  approach can be applied to any unorganized set of points. This 3D level set method shrinks an initial guess to a smooth surface on the given data. Finally, some geometric descriptors, such as surface areas and volumes, are computed based on these reconstructed models for further shape analysis.

Josh Knutson presents at the Celebration of Creative Inquiry (Photo by Tom Roster)

Three students in Gustavus’s Department of Mathematics and Computer Science presented their honors thesis research recently. The photo shows Josh Knutson at the college-wide Celebration of Creative Inquiry presenting his work on the use of subdivision surfaces for three-dimensional graphics. Knutson also presented the work to the department, earning honors in both mathematics and computer science for his work under Mike Hvidsten’s supervision. Another student with a double-duty honors thesis was Sarah Cowles. For her honors majors in mathematics and biology, she presented a mathematical analysis of lion vocalizations, supervised by Tom LoFaro and Jon Grinnell. Alex Wauck’s honors thesis in computer science, supervised by Max Hailperin, merged two previously separate program-improving transformations. All three students will be among those graduating this Sunday.

I would like to encourage you to participate in this trip, even if career issues are not only your immediate horizon.  When we visited Federated before, students found it very valuable to hear some alumni perspectives, even if their own careers were likely to go down different paths.

Our bus will leave Olin Hall at 10:00am on March 6, and return by 3:45 that afternoon. Over lunch, we will hear about the actuarial and information services areas.  Then we will split up to follow individual alumni from either actuarial or information systems to their work sites and talk with them in more depth.

In order to help our hosts plan logistics, please email Max Hailperin with your estimated probability of attendance.  If you send me a non-zero probability, I’ll be back in touch with you as we get closer to the event.  It would also help if you indicated which of the two areas you want to split off into.

I recognize that you may have classes meeting during this block of time on a Friday and that class attendance is important.  I would ask you to weigh the value of this trip against the importance of those classes, and consider talking with your professors about ways you could minimize the damage done by going on the trip.

And how, exactly, did Brostom get elected?   “Actually, I’ve been on the Hall of Fame Board for 10 years which makes the selections.  I pride myself on perfect attendance.  But I had a doctor’s appointment and I couldn’t make that meeting.  I come to the next meeting and find out that they suspended the bylaws [forbidding election of a board member] and unanimously put me into the Hall of Fame.  I thought, wow! I should have missed earlier …”  (My editorialization: don’t try this at home.  This tactic of missing meetings could backfire unless you have done so remarkably much to earn so many people’s admiration.)

In the Introduction to Computer Science II, I’m planning on illustrating iterative numerical calculations by using an algorithm for approximating pi that was developed in the third century by Liu Hui and apparently used in the fifth century by Zu Chongzhi to calculate an approximation so precise that no one improved upon it for a millenium to come.  (This seems to be the longest any approximation to  pi ever has remained the record-holder, at least with the exception of 3, which was used so early as to be shrouded in the mists of time.)

In Computer Organization, I’m going to tell a story that definitely fits into the category of truth stranger than fiction.  A 17th century German Lutheran, collaborating with French Jesuits, becomes convinced not only that binary numerals express the perfection of God’s creation, but more remarkably that the Chinese had encountered the same truth thousands of years earlier.  In effect, the Chinese were Christians thousands of years before Christ himself!  (And, moreover, the Chinese emperor could be converted to Christianity if this were explained to him.)  Such, in the barest outline, is the story of Leibniz’s encounter with the Yi Jing, also known as the I Ching or the Book of Changes.

Finally, in Networking, we will follow up our discussion of network security by considering how broader conceptions of security–political and societal security–are realized through a combination of technical and non-technical means in various parts of the world.  Our example will be the control China exercises over the Internet, in which the technical filtering component is often called “The Great Firewall of China”.

Fibonacci, by Bethany Ringdal

They
don’t
march in
time, how I
thought I would find them;
these numbers slide, hum and nestle
in the pearly curves and coils of a poem in the sun.

Untitled, by Erik Alquist

Vote.
Please.
Cast with
Conviction
To send a message
Of preference or discontent.
Though with the plurality you may not be, have heart.
Choosing the loser of these contests beats waiting for a probability of 1.

Untitled, by Katie O’Bryan

guess
choose
who knows?
not anchors
nor politicians
who can predict, the oracle?
no, tis not the mystic but tis the statistician