Inna Pivkina

Young women in computing : lessons learned from an educational & outreach program

This paper describes the Young Women in Computing program, an ongoing outreach program in Computer Science at New Mexico State University (NMSU). Features of the program include summer camps and academic year activities, computing in context, peer mentoring, and role models. The main goal is to increase interest in computing among female high school students. The paper discusses lessons learned from three years of experience with the program.

Revision Programming = Logic Programming + Integrity Constraints

We study revision programming, a logic-based mechanism for enforcing constraints on databases. The central concept of this approach is that of a justified revision based on a revision program. We show that for any program P and for any pair of initial databases I and I’ we can transform (shift) the program P to a program P’ so that the size of the resulting program does not increase and so that P-justified revisions of I are shifted to P’-justified revisions of I’. Using this result we show that revision programming is closely related to a subsystem of general logic programming of Lifschitz and Woo. This, in turn, allows us to reduce revision programming to logic programming extended by the concept of a constraint with a suitably modified stable model semantics. Finally, we use the connection between revision programming and general logic programming to introduce a disjunctive version of our formalism.

Annotated revision programs

Revision programming is a formalism to describe and enforce updates of belief sets and databases. That formalism was extended by Fitting who assigned annotations to revision atoms. Annotations provide a way to quantify the confidence (probability) that a revision atom holds. The main goal of our paper is to reexamine the work of Fitting, argue that his semantics does not always provide results consistent with intuition, and to propose an alternative treatment of annotated revision programs. Our approach differs from that proposed by Fitting in two key aspects: we change the notion of a model of a program and we change the notion of a justified revision. We show that under this new approach fundamental properties of justified revisions of standard revision programs extend to the annotated case.

Proactively applied encryption in multipath networks

In providing data privacy on multipath networks, it is important to conserve bandwidth by ensuring that only the necessary level of encryption is applied to each path. This is achieved by dispersing data along multiple secure paths in such a way that the highest encryption level is applied to those paths where threats are most likely to be present. Conversely, for those paths where the likelihood of attack is least, the encryption levels should be commensurately lower. In order to maintain data privacy, path encryption level adjustments should be proactive. In so doing, the multipath network should have the ability to calculate the probability of an attack and proactively adjust the encryption strength long before the final steps of an attack sequence occur. The unique methods described in this research, are able to sense when an attack sequence is initiated on a path. This is achieved by calculating the probability of the presence of specific attack sequence signatures along each network path using statistical learning techniques, and by deriving path information assurance levels using these probabilities. As an attack sequence progresses, the likelihood of the presence of specific attacks grows until a threshold level is met and an encryption adjustment for a path is warranted.

Cheshire: Towards an Alice Based Game Development Tool

This paper presents on-going research that aims to modify the open source 3D programming environment Alice in order to adapt it for use as a development tool for teaching game programming. The advantages and disadvantages of the current version of Alice for game development are described, along with an account of experiences using Alice for game development in the classroom. We set forth the changes that we plan to make to Alice and the challenges that we are facing.

Revising knowledge in multi-agent systems using revision programming with preferences

In this paper we extend the Revision Programming framework—a logic-based framework to express and maintain constraints on knowledge bases—with different forms of preferences. Preferences allow users to introduce a bias in the way agents update their knowledge to meet a given set of constraints. In particular, they provide a way to select one between alternative feasible revisions and they allow for the generation of revisions in presence of conflicting constraints, by relaxing the set of satisfied constraints (soft constraints). A methodology for computing preferred revisions using answer set programming is presented.

Dynamically Differentiated Multipath Security in Fixed Bandwidth Networks

Networks can be secured using a secure quality of service approach in which a sender disperses data along multiple secure paths. In this secure multipath approach, a portion of the data from the sender is transmitted over each path on fixed bandwidth networks, and the receiver assembles the data fragments that arrive. The research presented explores the effects of cloud infrastructure attack scenarios, and gauges the threat levels along each path. Optimal sampling and compression via compressed sensing is employed in order to minimize the possibility of dropped packets and missed attacks. The probability of the presence of specific attack signatures along each network path is determined using statistical learning techniques. Path information assurance levels are derived using these probabilities and encryption strengths are dynamically increased along those paths found to be most vulnerable. As compared to statically employed path encryption schemes, the devised methods in this research significantly increase data throughput on fixed bandwidth networks.

Annotated Revision Programs

Revision programming was introduced as a formalism to describe and enforce updates of belief sets and databases. Revision programming was extended by Fitting who assigned annotations to revision atoms. Annotations provide a way to quantify certainty (likelihood) that a revision atom holds. The main goal of our paper is to reexamine the work of Fitting, argue that his semantics does not always provide results consistent with intuition and to propose an alternative treatment of annotated revision programs. Our approach differs from that proposed by Fitting in two key aspects: we change the notion of a model of a program and we change the notion of a justified revision. We show that under this new approach fundamental properties of justified revisions of standard revision programs extend to the case of annotated revision programs.

Peer learning assistants in undergraduate computer science courses

The paper describes the experience of using undergraduate students as peer learning assistants (PLAs) in different undergraduate computer science courses which have graduate teaching assistants (TAs) as well. Depending on the course, PLAs have some of the following roles - holding office hours, helping with the labs and tutorials, facilitating student group work in class. The impact of PLAs on student learning outcomes is assessed by comparing student grades in the offerings of the course with and without PLAs and comparing the numbers of student visits outside of the class meeting times to the instructor, to the TAs, and to the PLAs. In addition to that, questionnaires are used to solicit feedback from students and PLAs about their experience. We find that the use of PLAs results in statistically significant increase in student course grades and decrease in the number of non-passing grades. Student experiences with PLAs are very positive. Many students prefer to seek help from the PLAs rather than from the TAs or instructor. PLAs report that the experience was beneficial to them, too. The paper discusses benefits of using PLAs, student preferences regarding PLAs and TAs, and what practices worked best.

Historical sources as a teaching tool

The session will introduce participants to curricular modules (projects) based entirely on primary historical source material, developed by an interdisciplinary team of seven computer science and mathematical sciences faculty at New Mexico State University and Colorado State University Pueblo. More than twenty projects have been developed and are available on the Internet at: http://www.cs.nmsu.edu/historical-projects/ . The projects are intended for courses in discrete mathematics, algorithm design, automata, graph theory, and logic.