Inna Pivkina

New Mexico State University, Computer Science, Faculty Member

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Papers by Inna Pivkina

Annotated revision programs

Artificial Intelligence, Jun 1, 2002

Revision programming is a formalism to describe and enforce updates of belief sets and databases.... more 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.

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Adoption of a three-part approach in a discrete mathematics course

Journal of Computing Sciences in Colleges, Apr 1, 2013

ABSTRACT The paper describes the experience of using a new teaching approach in a lower-level dis... more ABSTRACT The paper describes the experience of using a new teaching approach in a lower-level discrete mathematics course for computer science students. The approach replaces lectures by active student work in class. Assignments consist of three parts: part A, part B, and part C. Part A assignments ask students to read new material and answer some questions on the reading before the material is discussed in class. Part B assignments consist of some exercises on the new material which students do in groups in class and present solutions on the board. Part C assignments are regular individual homework assignments. The approach was used two times. The second time it was modified based on students&#39; feedback. Student questionnaires were administered in the middle and in the end of the semester to assess students&#39; reactions to the teaching approach. The paper describes the approach and its modification in details, provides examples of assignments, and presents students&#39; reactions to it.

Processing of experimental data using discretization of their domains

Optoelectronics, Instrumentation and Data Processing, Oct 1, 2010

ABSTRACT A method for processing observation data based on their discretization and graphical ana... more ABSTRACT A method for processing observation data based on their discretization and graphical analysis is proposed. The purpose of the processing is to determine and model the functional relationship between the inputs and output of an experimental object. The case of a series of experiments is considered.

Session details: Special session

SIGCSE bulletin, Mar 4, 2009

Historical sources as a teaching tool

The session will introduce participants to curricular modules (projects) based entirely on primar... more 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.

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Minimality of a solution update in conflict resolution: An application of revision programming to the von Neumann-Morgenstern approach

International Journal of Intelligent Systems, 2005

In a 1944 book that started game theory (and mathematical approach to conflict resolution), von N... more In a 1944 book that started game theory (and mathematical approach to conflict resolution), von Neumann and Morgenstern proposed the notion of a solution. When the situation changes, the old solution is often no longer a solution, so it needs to be updated. In practical applications, it is usually desirable to keep the solution change "minimal" in some reasonable sense. We show that for a seemingly straightforward formalization of this minimality, checking whether a change is minimal is NP-hard. We also show that by representing the notion of a solution as a collection of revision rules, we can produce a reasonable notion of minimality for which there exists a feasible algorithm for checking minimality of update.

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Revision Programming = Logic Programming + Integrity Constraints

Lecture Notes in Computer Science, 1999

We study revision programming, a logic-based mechanism for enforcing constraints on databases. Th... more We study revision programming, a logic-based mechanism for enforcing constraints on databases. The central concept of this approach is that of a justi ed revision based on a revision program. We show that for any program P and for any pair of initial databases I and I 0 we can transform (shift) the program P to a program P 0 so that the size of the resulting program does not increase and so that P-justi ed revisions of I are shifted to P 0-justi ed revisions of I 0. 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 modi ed stable model semantics. Finally, we use the connection between revision programming and general logic programming to introduce a disjunctive version of our formalism. Revision rules also have a computational interpretation that expresses a preferred way to enforce a constraint. Namely, assume that all data items a i , 1 i m, belong to the current database, say I, and none of the data items b j , 1 j n, belongs to I. Then, to enforce the constraint (1), the item a must be added to the database (removed from it, in the case of the constraint (2)), rather than some item a i removed or some item b j added. Consequently, R is a P-justi ed revision of I (in fact, unique).

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Original historical sources in data structures and algorithms courses

Journal of Computing Sciences in Colleges, Apr 1, 2011

ABSTRACT Data Structure and Algorithms courses are often hard for students. Can the use of projec... more ABSTRACT Data Structure and Algorithms courses are often hard for students. Can the use of projects based on original historical sources make it a better experience for students? The paper describes three such projects which were used to cover some of the material in Data Structures and Algorithms courses. Classroom experience with the projects and student reactions to them are presented.

Peer learning assistants in undergraduate computer science courses

The paper describes the experience of using undergraduate students as peer learning assistants (P... more 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.

Approximating Answer Sets of Unitary Lifschitz-Woo Programs

Lecture Notes in Computer Science, 2005

We investigate techniques for approximating answer sets of general logic programs of Lifschitz an... more We investigate techniques for approximating answer sets of general logic programs of Lifschitz and Woo, whose rules have single literals as heads. We propose three different methods of approximation and obtain results on the relationship between them. Since general logic programs with single literals as heads are equivalent to revision programs, we obtain results on approximations of justified revisions of databases by revision programs.

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A project in algorithms based on a primary historical source about catalan numbers

We discuss a project based on an original source from 1838 by Gabriel Lamé, which was used to tea... more We discuss a project based on an original source from 1838 by Gabriel Lamé, which was used to teach dynamic programming in an Algorithms and Data Structures course for junior level computer science students. The project was developed as part of a group effort at New Mexico State University on using original historical sources in teaching. The project is based on an excerpt from a letter of Monsieur Lamé to Monsieur Liouville on the question: Given a convex polygon, in how many ways can one partition it into triangles by means of diagonals? A variety of tasks in the project, which includes reading, writing, proving statements by mathematical induction, deriving formulas, writing computer programs and analyzing and comparing them for efficiency, help students to develop verbal, analytical and discrete mathematics skills necessary for computer science. We also discuss student reactions to the project and to learning from historical sources.

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Dynamically Differentiated Multipath Security in Fixed Bandwidth Networks

ABSTRACT Networks can be secured using a secure quality of service approach in which a sender dis... more ABSTRACT 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.

Minimality of a solution update in conflict resolution: An application of revision programming to the von Neumann–Morgenstern approach: Research Articles

Journal of intelligent systems, Sep 1, 2005

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Finding Least Expensive Tolerance Solutions and Least Expensive Tolerance Revisions: Algorithms and Computational Complexity

For an engineering design, tolerances in design parameters are selected so that within these tole... more For an engineering design, tolerances in design parameters are selected so that within these tolerances, we guarantee the desired functionality. Feasible algorithms are known for solving the corresponding computational problems: the problem of finding tolerances that guarantee the given functionality, and the problem of checking whether given tolerances guarantee this functionality. In this paper, we show that in many practical problems, the problem of choosing the optimal tolerances can also be solved by a feasible algorithm. We prove that a slightly different problem of finding the optimal tolerance revision is, in contrast, computationally difficult (namely, NP-hard). We also show that revision programming algorithms can be used to check whether a given combination of tolerance changes is optimal under given constraints-and even to find a combination that is optimal under given constraints.

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Relationship between time management in courses with online interactive textbooks and students' performance

The study aims to explore the relationship between time management in courses with online interac... more The study aims to explore the relationship between time management in courses with online interactive textbooks and students' performance. The study was done in two computer science courses — a second-year course on discrete mathematics for computer science and a first-year programming course. Each course used a required online interactive textbook on the course topic. Students had reading assignments that consisted of reading specified sections from the textbook and doing interactive activities from these sections. In discrete mathematics course reading assignments on a topic were due before the class period in which the topic was discussed. In the other course reading assignments were due after the material was discussed in class. For each student, we measured whether they tended to finish reading assignments early or late. We studied the relationship between this tendency of students and their academic performance in the courses. We found that students who tended to do their reading assignments early performed statically significantly better than students who tended to do their reading assignments late in discrete mathematics course where reading assignments were due before topics were discussed in class. In the other course, there was no statistically significant difference in performance among these groups of students.

Designing Student Projects for Teaching and Learning Discrete Mathematics and Computer Science via Primary Historical Sources

Based on a workshop presented at the HPM Group Satellite Meeting of ICME 11

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Revision programming: a knowledge representation formalism

Revision rules specify logical constraints on databases. For example, the rule (1.1) (called an i... more

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Proactively applied encryption in multipath networks

Computers & Security, May 1, 2016

In providing data privacy on multipath networks, it is important to conserve bandwidth by ensurin... more 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.

$Research paper thumbnail of Iterative Phase Retrieval Coherent Diffraction Imaging Algorithm$

Iterative Phase Retrieval Coherent Diffraction Imaging Algorithm

Bulletin of the American Physical Society, 2016

nanoscience and nanoscale materials requires non-destructive probes capable of mapping the local ... more nanoscience and nanoscale materials requires non-destructive probes capable of mapping the local structure (shape, chemical homogeneity and density modulations) in three dimensions of materials functional properties such as strain and electron density distribution. The Bragg Coherent Diffraction Imaging (BCDI) method has been developed for nondestructive imaging of 3D strain evolution within small crystals. This has widespread applications for medicine, material science and condensed matter systems. The inversion of diffraction data is a critical step that uses a computer algorithm that takes advantage of internal redundancies when the measurement points are spaced close enough together to meet the "oversampling" requirement. The first step is to postulate a 3D "support" volume in which all the sample density will be constrained to exist. Arguably, the bestmethod so far for phase. Here we demonstrate the development of a BCDI inversion algorithm that combines HIO, ER and phase constraint HIO to retrieve the phases and amplitudes from measured diffraction patterns. We demonstrate the applicability of the technique to imaging polar distortions in complex BaFe12O19 nanoparticles showing room temperature magneto-electric coupling.

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Annotated Revision Programs

Lecture Notes in Computer Science, 1999

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