Jonathan P. Sorenson

EPICS: A Service Learning Program at Butler University

Jonathan P. Sorenson et al. — Mon, 01 Mar 2010 07:01:38 PST

In this paper we present our experiences teaching EPICS (Engineering Projects In Community Service) at Butler University, a small, private university, from within the Department of Computer Science and Software Engineering. The EPICS program began at Purdue University in 1995. The idea behind EPICS is to have undergraduate students earn college credit for working on long-term, multi-semester projects to benefit charity and non-profit organizations. The projects are student-driven, under faculty supervision. There are many good reasons for having an EPICS program in an undergraduate computer science major. It is excellent for leveraging knowledge from other areas of computer science such as databases, networks, operating systems, and of course software engineering. The students are highly motivated because the project is real: there are real clients who use the software, making the software lifecycle come to life. Students practice teamwork, project management, professionalism, and communication skills. In our paper, we share feedback from our students on what EPICS means to them. At Butler, EPICS has been a success. Our EPICS program started in the Fall 2001 semester. We now have two ongoing projects: Spanish-In-Action (SIA), with Spanish middle school teachers from Crispus Attuchs Middle School in Indianapolis as clients, and Social Assets and Vulnerabilities Indicators (SAVI), with the POLIS Center at IUPUI as the client. We describe both projects in some detail in our paper. EPICS currently counts towards both the computer science major and the software engineering major as an elective at Butler. Our department has about 50 students and 4 full-time faculty, and each semester we have roughly 15 students enrolled in EPICS. We elaborate on how EPICS fits into our curriculum and provide details on how we deliver this course in our paper.

Computing Prime Harmonic Sums

Eric Bach et al. — Mon, 01 Mar 2010 06:29:46 PST

We discuss a method for computing Σ 𝑝≤𝑥 1/𝑝, using time about 𝑥2/3 and space about 𝑥1/3. It is based on the Meissel-Lehmer algorithm for computing the prime-counting function 𝜋(𝑥), which was adapted and improved by Lagarias, Miller, and Odlyzko. We used this algorithm to determine the first point at which the prime harmonic sum first crosses.

Modular exponentiation via the explicit Chinese remainder theorem

Daniel J. Bernstein et al. — Thu, 25 Feb 2010 09:25:20 PST

In this paper we consider the problem of computing xe mod m for large integers x, e, and m. This is the bottleneck in Rabin’s algorithm for testing primality, the Diffie-Hellman algorithm for exchanging cryptographic keys, and many other common algorithms.

The Pseudosquares Prime Sieve

Jonathan P. Sorenson — Wed, 24 Feb 2010 12:09:09 PST

We present the pseudosquares prime sieve, which finds all primes up to n.

Fast Bounds on the Distribution of Smooth Numbers

Scott T. Parsell et al. — Wed, 24 Feb 2010 12:03:45 PST

In this paper we present improvements to Bernstein’s algorithm, which finds rigorous upper and lower bounds for (x, y).

Genetic Algorithms for the Extended GCD Problem

Jonathan P. Sorenson — Wed, 24 Feb 2010 11:47:33 PST

We present several genetic algorithms for solving the extended greatest common divisor problem. After defining the problem and discussing previous work, we will state our results.

A Randomized Sublinear Time Parallel GCD Algorithm for the EREW PRAM

Jonathan P. Sorenson — Sat, 16 Jan 2010 11:56:47 PST