Mihaela C. Sabin

Greater efficiency for conditional constraint satisfaction

A conditional constraint satisfaction problem (CCSP) extends a standard constraint satisfaction problem (CPS) with a condition-based component that controls what variables participate in problem solutions. CCSPs adequately represent configuration and design problems in which selected subsets of variables, rather than the entire variable set, are relevant to final solutions. The only algorithm that is available for CCSP and operates directly on the original, unreformulated CCSP statement has been basic backtrack search. Reformulating CCSPs into standard CSPs has been proposed in order to bring the full arsenal of CSP algorithms to bear. One reformulation approach adds null values to variable domains and transforms CCSP constraints into CSP constraints. However, a complete null-based reformulation of CCSPs has not been available. In this paper we provide more advanced algorithms for CCSP and a full null-based reformulation into standard CSP. Thorough testing reveals that the advanced algorithms perform up to two orders of magnitude better than plain backtracking, but that realizing practical advantages from reformulation is problematic. The advanced algorithms extend forward checking and maintaining arc consistency to CCSPs. The null-based reformulation improves on the preliminary findings in [1] by removing the limitation on multiple activation, and by localizing changes. It identifies and addresses a difficulty presented by activity cycles.

Generating diagnostic tools for network fault management

Today’s network management applications mainly collect and display information, while providing limited information processing and problem-solving capabilities. A number of different knowledge-based approaches have been proposed to correct this deficiency, evolving from rule-based systems through case-based systems, to more recent model-based systems. Part of this evolution has been the recognition of the importance of constraints in a management context. This makes possible the assimilation into network management of a mature, theoretically developed technology from artificial intelligence, namely, the constraint satisfaction problem (CSP). In this paper we investigate the role of constraints in manipulating management data, and give an example of the use of the constraint satisfaction framework in diagnosing problems arising with Internet domain name service configurations. We also present ADNET, a system for automatically constructing C++ diagnostic programs from a model written in a simple modeling language.

A collaborative and experiential learning model powered by real-world projects

Information Technology (IT) curriculas strong application component and its focus on user centeredness and team work require that students experience directly real-world projects for real users of IT solutions. Although the merit of this IT educational tenet is universally recognized, delivering collaborative and experiential learning has its challenges. Reaching out to identify projects formulated by actual organizations adds significantly to course preparation. There is a certain level of risk involved with delivering a useful solution while, at the same time, enough room should be allowed for students to experiment with, be wrong about, review, and learn. Challenges pertaining to the real-world aspect of problem-based learning are compounded by managing student teams and assessing their work such that both individual and collective contributions are taken into account. Finally, the quality of the project releases is not the only measure of student learning. Students should be given meaningful opportunities to practice, improve, and demonstrate their communication and interpersonal skills. In this paper we present our experience with two courses in which teams of students worked on real-world projects involving three external partners. We describe how each of the challenges listed above has impacted the course requirements, class instruction, team dynamics, assessment, and learning in these courses. Course assessment and survey data from students are linked to learning outcomes and point to areas where the collaborative and experiential learning model needs improvement.

A constraint-based approach to fault management for groupware services

There is no standard model at the service layer. However, fault management to distributed services and applications needs to construct and utilize complex models of the participating objects and their interdependencies. Thus, model-based fault management tools can predict the correct behavior of diagnosed systems and use the resulting predictions to identify faults. When used on-line in real systems, diagnostic tools based on such models should be able to provide prompt response and accurate, comprehensive explanations of the root causes of faults. In this paper we propose to address these requirements: modeling, proactive diagnosis, and explanation. We apply a recent extension to the constraint satisfaction paradigm, called composite constraint satisfaction, to facilitate modeling of complex systems, and we use constraint propagation techniques to support proactive diagnosis and explanation. We demonstrate the applicability of our approach on an example of a basic groupware service, namely, distributed database replication.

A Constraint-Based Approach to Diagnosing Software Problems in Computer Networks

Distributed software problems can be particularly mystifying to diagnose, for both system users and system administrators. Modelbased diagnosis methods that have been more commonly applied to physical systems can be brought to bear on such software systems. A prototype system has been developed for diagnosing problems in software that controls computer networks. Our approach divides this software into its natural hierarchy of layers, subdividing each layer into three separately modeled components: the interface to the layer above on the same machine, the protocol to the same layer on a remote machine, and the configuration. For each component knowledge is naturally represented in the form of constraints. User interaction modeling is accomplished through the introduction of constraints representing user assumptions, the finite-state machine specification of a protocol is translated to a standard CSP representation and configuration tasks are modeled as dynamic CSPs. Diagnosis is viewed as a partial constraint satisfaction problem (PCSP). A PCSP algorithm has been adapted for use as a diagnostic engine. This paper presents a case study illustrating the diagnosis of some problems involving the widely used FTP and DNS network software.

ACM/IEEE-CS Information Technology Curriculum 2017: A Status Update

The IT2008 Curriculum Guidelines for Undergraduate Degree Programs in Information Technology is showing its age, and in 2014, the ACM Education Board agreed to oversee the creation of a revision, now being referred to as IT2017. Members of the IT 2017 Task Group have been identified, and phone conference calls have been taking place. All proposed panel members are members of the IT2017 Task Group.

Free and open source software in computing education

Free and Open Source Software (FOSS) exemplifies the merit and successes of open content, understood broadly as creative work that explicitly allows sharing and further changes by anyone, whether an individual or organization. Although the benefits of improving computing education with open source practices are largely acknowledged, transforming teaching to create effective learning environments has many challenges. The panelists will bring different perspectives on teaching strategies and curricular content they have used in their classrooms. These perspectives will exemplify key issues with FOSS-based education and FOSS-based IT systems. The developer and user communities established around FOSS-based IT systems are of particular interest to the IT discipline because of its focus on user centeredness and advocacy for advancing professional practices in authentic environments.

Updating the ACM/IEEE 2008 Curriculum in Information Technology (Abstract Only)

At the direction of the ACM Education Board, the IT2017 Task Group was formed with the charge of updating the joint ACM and IEEE Computer Society Curriculum Guidelines for Undergraduate Degree Programs in Information Technology, known as IT2008. The revised document, called IT2017, should be appropriately forward looking given the significant advances in information technology that have occurred since 2008. Participants attending the BOF will contribute their insights and assist with the revision process to update IT2008. Discussions will center on delineating knowledge areas and learning outcomes specific to IT; exploring the current and future roles of IT in computing disciplines; recommending changes to improve the usefulness of the report; and planning further communications to fully engage the academic and professional community in the revision process. The objective is to ensure that the updated document is a forward-looking curriculum framework of the disciplinary content and practices in the field of information technology and remains relevant into 2020 and beyond for incoming students, computing departments with IT programs, accreditation bodies, and employers in the U.S. and anywhere else in the world.

Make and Learn: A CS Principles Course Based on the Arduino Platform

We present preliminary experiences in designing a Computer Science Principles undergraduate course for all majors that is based on physical computing with the Arduino microprocessor platform. The course goal is to introduce students to fundamental computing concepts in the context of developing concrete products. This physical computing approach is different from other existing CS Principles courses. Students use the Arduino platform to design tangible interactive systems that are personally and socially relevant to them, while learning computing concepts and reflecting on their experiences. In a previous publication [1], we reported on assessment results of using the Arduino platform in an Introduction to Digital Design course. We have introduced this platform in an introductory computing course at the University of Hartford in the past year as well as in a Systems Fundamentals Discovery Course at the University of New Hampshire to satisfy the general education requirements in the Environment, Technology, and Society category. Our goal is to align the current curriculum with the CS Principles framework to design a course that engages a broader audience through a creative making and contextualized learning experience.

Latin American Perspectives to Internationalize Undergraduate Information Technology Education

The computing education community expects modern curricular guidelines for information technology (IT) undergraduate degree programs by 2017. The authors of this work focus on eliciting and analyzing Latin American academic and industry perspectives on IT undergraduate education. The objective is to ensure that the IT curricular framework in the IT2017 report articulates the relationship between academic preparation and the work environment of IT graduates in light of current technological and educational trends in Latin America and elsewhere. Activities focus on soliciting and analyzing survey data collected from institutions and consortia in IT education and IT professional and educational societies in Latin America; these activities also include garnering the expertise of the authors. Findings show that IT degree programs are making progress in bridging the academic-industry gap, but more work remains.