18 research outputs found
CS Circles: An In-Browser Python Course for Beginners
Computer Science Circles is a free programming website for beginners that is
designed to be fun, easy to use, and accessible to the broadest possible
audience. We teach Python since it is simple yet powerful, and the course
content is well-structured but written in plain language. The website has over
one hundred exercises in thirty lesson pages, plus special features to help
teachers support their students. It is available in both English and French. We
discuss the philosophy behind the course and its design, we describe how it was
implemented, and we give statistics on its use.Comment: To appear in SIGCSE 201
Recommended from our members
The influence of gender pairing of perpetrator and victim on perceptions of sexual harassment
The influence of gender pairing of perpetrator and victim on students\u27 perceptions of the degree of severity and offensiveness of sexual harassment, as well as the degree of likelihood of the scenarios depicting sexual harassment occurring in an actual work setting were investigated
On the iteration of certain quadratic maps over GF(p)
AbstractWe consider the properties of certain graphs based on iteration of the quadratic maps x→x2 and x→x2−2 over a finite field GF(p)
Graphs associated with the map in finite fields of characteristic three
In this paper we study the structure of the graphs associated with the
iterations of the map over finite fields of characteristic
three.Comment: The definitions of the maps and have been slightly
modified in order to simplify the following discussion. 6 page
Error Detection in Number-Theoretic and Algebraic Algorithms
CPU's are unreliable: at any point in a computation, a bit may be altered with some (small) probability. This probability may seem negligible, but for large calculations (i.e., months of CPU time), the likelihood of an error being introduced becomes increasingly significant. Relying on this fact, this thesis defines a statistical measure called robustness, and measures the robustness of several number-theoretic and algebraic algorithms.
Consider an algorithm A that implements function f, such that f has range O and algorithm A has range O' where O⊆O'. That is, the algorithm may produce results which are not in the possible range of the function. Specifically, given an algorithm A and a function f, this thesis classifies the output of A into one of three categories:
1. Correct and feasible -- the algorithm computes the correct result,
2. Incorrect and feasible -- the algorithm computes an incorrect result and this output is in O,
3. Incorrect and infeasible -- the algorithm computes an incorrect result and output is in O'\O.
Using probabilistic measures, we apply this classification scheme to quantify the robustness of algorithms for computing primality (i.e., the Lucas-Lehmer and Pepin tests), group order and quadratic residues.
Moreover, we show that typically, there
will be an "error threshold" above which the algorithm is unreliable (that is, it will rarely give the correct result)
Around Pelikan's conjecture on very odd sequences
Very odd sequences were introduced in 1973 by J. Pelikan who conjectured that
there were none of length >=5. This conjecture was disproved by MacWilliams and
Odlyzko in 1977 who proved there are in fact many very odd sequences. We give
connections of these sequences with duadic codes, cyclic difference sets,
levels (Stufen) of cyclotomic fields, and derive some new asymptotic results on
their lengths and on S(n), which denotes the number of very odd sequences of
length n.Comment: 21 pages, two tables. Revised version with improved presentation and
correction of some typos and minor errors that will appear in Manuscripta
Mathematic
Squares and overlaps in the Thue-Morse sequence and some variants
We consider the position and number of occurrences of squares in the Thue-Morse sequence, and show that the corresponding sequences are 2-regular. We also prove that changing any finite but nonzero number of bits in the Thue-Morse sequence creates an overlap, and any linear subsequence of the Thue-Morse sequence (except those corresponding to decimation by a power of 2) contains an overlap.http://www.numdam.org/item/ITA_2006__40_3_473_0
On the Iteration of Certain Quadratic Maps over GF(p)
We consider the properties of certain graphs based on iteration of the quadratic maps x ! x and x ! x 2 over a finite field GF(p)
Objective Scoring for Computing Competition Tasks
Computing competitions like the International Olympiad in Informatics (IOI) typically pose several problems that contestants are required to solve by writing a program. The program is tested automatically on several sets of input data to determine whether or not it computes the correct answer within specified time and memory limits. We consider the controversy of whether and how to award partial credit for programs that fail some of the tests. Using item response theory, we analyze the degree to which the scores from these automatic tests, separately and in various combinations, truly reflect the contestants ’ achievement.
Squares and overlaps in the Thue-Morse sequence and some variants
We consider the position and number of occurrences of squares
in the Thue-Morse sequence, and show that the corresponding sequences
are 2-regular. We also prove that changing any finite but nonzero
number of bits in the Thue-Morse sequence creates an overlap, and any
linear subsequence of the Thue-Morse sequence (except those corresponding
to decimation by a power of 2) contains an overlap