Digital Commons Network^™

New Fellow: Robert A. Willis, Jr.

Virginia Journal of Science

Robert A. Willis, Jr. has been named Fellow of the Virginia Academy of Science. He has been an active member of the Virginia Academy of Science and the Association of Departments of Computer, Information Science/Engineering at Minority Institutions (ADMI) for nearly fifteen years.

Cs 340: Programming Language Workshop In Java, Krishnaprasad Thirunarayan

Computer Science & Engineering Syllabi

This course is designed as a self-study in Java. You are expected to learn the Java language and solve a set of programming problems assigned to you using it. (You may develop your code using any IDE you like, but you must ensure that it eventually runs using JDK 5). There are no exams. We officially meet only once in a quarter. However, I will be available in the posted office hours for clarifications and discussions about the programming problems.

Answer Set Programming Based On Propositional Satisfiability, Enrico Giunchiglia, Yuliya Lierler, Marco Maratea

Computer Science Faculty Publications

Answer set programming (ASP) emerged in the late 1990s as a new logic programming paradigm that has been successfully applied in various application domains. Also motivated by the availability of efficient solvers for propositional satisfiability (SAT), various reductions from logic programs to SAT were introduced. All these reductions, however, are limited to a subclass of logic programs or introduce new variables or may produce exponentially bigger propositional formulas. In this paper, we present a SAT-based procedure, called ASPSAT, that (1) deals with any (nondisjunctive) logic program, (2) works on a propositional formula without additional variables (except for those possibly introduced …

Localization In Wireless Sensor Networks, Mark Terwilliger

Dissertations

With the proliferation of wireless sensor networks, providing location-aware technology and services to new applications have become important for developers. Localization is the problem of determining the positions of nodes in an ad hoc network. With the constrained resources of network sensors, providing robust localization services remains a fundamental research challenge facing the entire sensor network development community.

The initial localization problem that we addressed was to design and develop a working system that could locate equipment, such as a laptop or video projector. Ferret, the localization system developed, uses two different ranging techniques to help locate an object to …

A Practical Password-Based Two-Server Authentication And Key Exchange System, Yanjiang Yang, Robert H. Deng, Feng Bao

Research Collection School Of Computing and Information Systems

Most password-based user authentication systems place total trust on the authentication server where cleartext passwords or easily derived password verification data are stored in a central database. Such systems are, thus, by no means resilient against offline dictionary attacks initiated at the server side. Compromise of the authentication server by either outsiders or insiders subjects all user passwords to exposure and may have serious legal and financial repercussions to an organization. Recently, several multiserver password systems were proposed to circumvent the single point of vulnerability inherent in the single-server architecture. However, these multiserver systems are difficult to deploy and operate …

Extracting A Mobility Model From Real User Traces, Minkyong Kim, David Kotz, Songkuk Kim

Dartmouth Scholarship

Understanding user mobility is critical for simulations of mobile devices in a wireless network, but current mobility models often do not reflect real user movements. In this paper, we provide a foundation for such work by exploring mobility characteristics in traces of mobile users. We present a method to estimate the physical location of users from a large trace of mobile devices associating with access points in a wireless network. Using this method, we extracted tracks of always-on Wi-Fi devices from a 13-month trace. We discovered that the speed and pause time each follow a log-normal distribution and that the …

Whole Word Phonetic Displays For Speech Articulation Training, Fansheng Meng

Electrical & Computer Engineering Theses & Dissertations

The main objective of this dissertation is to investigate and develop speech recognition technologies for speech training for people with hearing impairments. During the course of this work, a computer aided speech training system for articulation speech training was also designed and implemented. The speech training system places emphasis on displays to improve children's pronunciation of isolated Consonant-Vowel-Consonant (CVC) words, with displays at both the phonetic level and whole word level. This dissertation presents two hybrid methods for combining Hidden Markov Models (HMMs) and Neural Networks (NNs) for speech recognition. The first method uses NN outputs as posterior probability estimators …

A Unified Log-Based Relevance Feedback Scheme For Image Retrieval, Steven Hoi, Michael R. Lyu, Rong Jin

Research Collection School Of Computing and Information Systems

Relevance feedback has emerged as a powerful tool to boost the retrieval performance in content-based image retrieval (CBIR). In the past, most research efforts in this field have focused on designing effective algorithms for traditional relevance feedback. Given that a CBIR system can collect and store users' relevance feedback information in a history log, an image retrieval system should be able to take advantage of the log data of users' feedback to enhance its retrieval performance. In this paper, we propose a unified framework for log-based relevance feedback that integrates the log of feedback data into the traditional relevance feedback …

A Component Based Formal Ontology Model, A Method For Evaluating Such A Model, And The Results Of An Application Of That Method, Charles Tumitsa

Computational Modeling & Simulation Engineering Theses & Dissertations

For systems to truly communicate effectively, more than just data interchange is necessary. The systems must achieve conceptual interoperability, which implies communicating with understanding.

The LCIM (Levels of Conceptual Interoperability Model) describes a number of levels of interoperability, each of which shows systems with an increased amount of conceptual understanding of the other systems they are communicating with. The lowest levels of this model, technical and syntactic interoperability, are achieved (and there are many existing examples) via data exchange in a number of different ways. Research has shown, however, that to attain higher levels of conceptual understanding, that there must …

An Interactive Relaxation Approach For Anomaly Detection And Preventive Measures In Computer Networks, Garrick A. Bell

Theses and Dissertations

It is proposed to develop a framework of detecting and analyzing small and widespread changes in specific dynamic characteristics of several nodes. The characteristics are locally measured at each node in a large network of computers and analyzed using a computational paradigm known as the Relaxation technique. The goal is to be able to detect the onset of a worm or virus as it originates, spreads-out, attacks and disables the entire network. Currently, selective disabling of one or more features across an entire subnet, e.g. firewalls, provides limited security and keeps us from designing high performance net-centric systems. The most …

Reversing Ticket Based Probing (Rtbp) Routing For Manet, Turgut Yucel

Electrical & Computer Engineering Theses & Dissertations

The delay-constrained maximum-bandwidth routing problem in MANET (Mobile Ad hoc Networks) is to find the maximum bandwidth path which satisfies a given delay constraint. The research challenge for this problem is that the networking information used for routing may be imprecise. The Ticket-Based Probing (TBP) routing algorithm provides a heuristic approach by using two types of ticket. In this thesis a Reversing Ticket-based Probing (RTBP) routing algorithm is proposed. The RTBP has two novel features compared to the original ticket based probing algorithms. The first feature is using just one type ticket, instead of two types of ticket. RTBP generates …

Understanding Powerpoint Through Rhetoric, Andrea K. Murphy

English Theses & Dissertations

PowerPoint has been described by critics and proponents alike as ubiquitous. This tool, created primarily for the business world, is now found everywhere from elementary school classes to the highest levels of government. Critics of PowerPoint, like Edward Tufte, charge the software with such crimes as the corruption of data and changing the way that people think. Meanwhile, PowerPoint proponents such as Cliff Atkinson and Richard E. Mayer assert PowerPoint's value as an excellent tool that, if designed properly, can take advantage of the promise of research into multimedia theory.

Even as we reconcile these diverse views within a larger …

Traffic Grooming, Routing, And Wavelength Assignment In Wdm Transport Networks With Sparse Grooming Resources, Osama Awwad

Masters Theses

While a single fiber strand in wavelength division multiplexing (WDM) has over a terabit-per-second bandwidth and a wavelength channel has over a gigabit-persecond transmission speed, the network may still be required to support traffic requests at rates that are lower than the full wavelength capacity. To avoid assigning an entire lightpath to a small request, many researchers have looked at adding traffic grooming to the routing and wavelength assignment (RWA) problem. In this work, we consider the RWA problem with traffic grooming (GRWA) for mesh networks under static and dynamic lightpath connection requests. The GRWA problem is NPComplete since it …

Enterprise Agility And The Enabling Role Of Information Technology, Eric Overby, Anandhi S. Bharadwaj, V. Sambamurthy

Research Collection School Of Computing and Information Systems

In turbulent environments, enterprise agility, that is, the ability of firms to sense environmental change and respond readily, is an important determinant of firm success. We define and deconstruct enterprise agility, delineate enterprise agility from similar concepts in the business research literature, explore the underlying capabilities that support enterprise agility, explicate the enabling role of information technology (IT) and digital options, and propose a method for measuring enterprise agility. The concepts in this paper are offered as foundational building blocks for the overall research program on enterprise agility and the enabling role of IT.

Anonymous Signature Schemes, Guomin Yang, Duncan S. Wong, Xiaotie Deng, Huaxiong Wang

Research Collection School Of Computing and Information Systems

Digital signature is one of the most important primitives in public key cryptography. It provides authenticity, integrity and non-repudiation to many kinds of applications. On signer privacy however, it is generally unclear or suspicious of whether a signature scheme itself can guarantee the anonymity of the signer. In this paper, we give some affirmative answers to it. We formally define the signer anonymity for digital signature and propose some schemes of this type. We show that a signer anonymous signature scheme can be very useful by proposing a new anonymous key exchange protocol which allows a client Alice to establish …

Mobius: An Omnidirectional Robotic Platform And Software Architecture For Network Teleoperation, Samuel Aaron Miller

Electrical & Computer Engineering Theses & Dissertations

The following thesis presents the results of a project to develop and test an omnidirectional robotic system (hardware and software) at NASA Langley Research Center's Robotics and Intelligent Machines Lab. The impetus for the project was the unique capabilities of omnidirectional systems. Some of the many potential benefits these systems have include improved material-handling capabilities in constrained environments (such as might be found in extraterrestrial manned habitats), efficient camera-based vehicle teleoperation, and simplified route planning for autonomous robot operations.

The project's focus was to design, build, and test a system that used Mecanum wheels to achieve omnidirectional motion. In addition …

Determining The Level Of Network Security Awareness Of Utc Students Living On Campus, Alma Cemerlic

Honors Theses

While information technology divisions in various schools often conduct surveys on general computer use, almost no studies have been done that directly targeted the level of Internet security awareness among college students. The National Cyber Security Alliance (NCSA), a not-for-profit, public-private partnership focused on increasing online security awareness, in collaboration with the Government and the Internet industry, organized a number of different projects designed to promote "safe online practices" among college students. However, since research has not been done to investigate the relationship between students' demographics and their Internet security awareness, it is not possible to tell how effective these …

Back Matter

Journal of Digital Forensics, Security and Law

No abstract provided.

Front Matter

Journal of Digital Forensics, Security and Law

No abstract provided.

A Selective Approach To Bandwidth Overbooking, Feng Huang

Theses and Dissertations

Overbooking is a technique used by network providers to increase bandwidth utilization. If the overbooking factor is chosen appropriately, additional virtual circuits can be admitted without degrading quality of service for existing customers. Most existing implementations use a single factor to accept a linear fraction of traffic requests. High values of this factor may cause the degradation of quality of service whereas low overbooking factors will result in underutilization of bandwidth. Network providers often select overbooking factors based only on aggregate average virtual circuit utilization. This paper proposes a selective overbooking scheme based on trunk size and usage profile. Experiments …

Learning Real-World Problems By Finding Correlated Basis Functions, Adam C. Drake

Theses and Dissertations

Learning algorithms based on the Fourier transform attempt to learn functions by approximating the largest coefficients of their Fourier representations. Nearly all previous work in Fourier-based learning has been in the theoretical realm, where properties of the transform have made it possible to prove many interesting learnability results. The real-world usefulness of Fourier-based methods, however, has not been thoroughly explored. This thesis explores methods for the practical application of Fourier-based learning. The primary contribution of this thesis is a new search algorithm for finding the largest coefficients of a function's Fourier representation. Although the search space is exponentially large, empirical …

Browser-Based Trust Negotiation, Cameron Morris

Theses and Dissertations

Trust negotiation allows two parties on the Internet to establish trust in each other according to the digital credentials thateach other possesses. Traditionally, trust negotiation uses certificates as digital credentials. However, certificates make trust negotiation difficult to use since people rarely have certificates available to them, and they must physically possess and secure all needed certificates in order to negotiate. To avoid these problems, this thesis proposes that credential authorities negotiate on behalf of the user. This thesis defines BrowserBased Trust Negotiation (BBTN) as a method for negotiating with credential authorities using the Secure Assertion Markup Language (SAML).

Encryption Of Computer Peripheral Devices, Kelly Robert Norman

Theses and Dissertations

Computer peripherals, such as keyboards, scanners, printers, cameras, and Personal Data Assistants (PDAs) typically communicate with a host PC via an unencrypted protocol, leaving them vulnerable to eavesdropping techniques, such as keyloggers. An encryption system was developed that is simple enough to be used in peripherals that do not have large amounts of processing power and memory. A software driver loaded in the operating system of the host computer communicates with a simple 8-bit microcontroller in the peripheral device. The driver handles key generation, key exchange, and provides decrypted data to the operating system. A key exchange protocol allows the …

Computer Network Security And Arl Libraries, Deeann Allison, Scott Childers

University of Nebraska-Lincoln Libraries: Faculty Publications

This article reviews current recommendations for computer security practices for staff computing, summarizes current practices in United States Association of Research Libraries and proposes further areas to explore.

Factors Impacting Key Management Effectiveness In Secured Wireless Networks, Yongjoo Shin

Theses and Dissertations

The use of a Public Key Infrastructure (PKI) offers a cryptographic solution that can overcome many, but not all, of the MANET security problems. One of the most critical aspects of a PKI system is how well it implements Key Management. Key Management deals with key generation, key storage, key distribution, key updating, key revocation, and certificate service in accordance with security policies over the lifecycle of the cryptography. The approach supported by traditional PKI works well in fixed wired networks, but it may not appropriate for MANET due to the lack of fixed infrastructure to support the PKI. This …

Type Ii Quantum Computing Algorithm For Computational Fluid Dynamics, James A. Scoville

Theses and Dissertations

An algorithm is presented to simulate fluid dynamics on a three qubit type II quantum computer: a lattice of small quantum computers that communicate classical information. The algorithm presented is called a three qubit factorized quantum lattice gas algorithm. It is modeled after classical lattice gas algorithms which move virtual particles along an imaginary lattice and change the particles’ momentums using collision rules when they meet at a lattice node. Instead of moving particles, the quantum algorithm presented here moves probabilities, which interact via a unitary collision operator. Probabilities are determined using ensemble measurement and are moved with classical communications …

Idf: An Inconsistency Detection Framework – Performance Modeling And Guide To Its Design, Yijun Lu, Xueming Li, Hong Jiang

School of Computing: Technical Reports

With the increased popularity of replica-based services in distributed systems such as the Grid, consistency control among replicas becomes more and more important. To this end, IDF (Inconsistency Detection Framework), a two-layered overlay-based architecture, has been proposed as a new way to solve this problem—instead of enforcing a predefined protocol, IDF detects inconsistency in a timely manner when it occurs and resolves it based on applications’ semantics.
This paper presents a comprehensive analytical study of IDF to assess its performance and provide insight into its design. More specifically, it develops an analytical model to characterize IDF. Based on this model, …

Scouting Ecommerce: Electronic Tracking For Girl Scouts, Melissa Roetker

Regis University Student Publications (comprehensive collection)

Girl Scout Troop #343 relies on parent volunteers to keep the troop functioning. The troop leaders would like to reduce time spent on paperwork, in order to allow volunteers to focus on time spent with the girls. Other than meetings, the most time consuming activity for volunteers is the manual tracking of paperwork. This includes financial paperwork, badge and activity status, personal data, and other such information. Troops are on their own to find a method for maintaining records, without local or national support. Currently, Troop #343 has moved the finances to an electronic format, which has left the badge …

Perspective Models As A Means For Achieving True Representational Accuracy, Kym Jason Pohl

Collaborative Agent Design (CAD) Research Center

Accurate and expressive representation of the subject matter over which a context-oriented, decision-support system operates is fundamental to the effectiveness and longevity of the resulting solution. Often taking the form of an ontology, such extensive representational models, by their very nature, are rich in both relationships and fine-grained objects. It is, however, these two strengths that can significantly increase complexity for its users in addition to adversely affecting system performance. Further, due to the multitude of compartmentalized facets (i.e., populations of distinct, reasoning agents) inherent in such software solutions, it is important to recognize that a single-minded omniscient set of …

Formal Mitigation Strategies For The Insider Threat: A Security Model And Risk Analysis Framework, Jonathan W. Butts

Theses and Dissertations

The advancement of technology and reliance on information systems have fostered an environment of sharing and trust. The rapid growth and dependence on these systems, however, creates an increased risk associated with the insider threat. The insider threat is one of the most challenging problems facing the security of information systems because the insider already has capabilities within the system. Despite research efforts to prevent and detect insiders, organizations remain susceptible to this threat because of inadequate security policies and a willingness of some individuals to betray their organization. To investigate these issues, a formal security model and risk analysis …