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2007

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Articles 271 - 300 of 1355

Full-Text Articles in Computer Sciences

Comparing Disjunctive Well-Founded Semantics, Matthias Knorr, Pascal Hitzler Sep 2007

Comparing Disjunctive Well-Founded Semantics, Matthias Knorr, Pascal Hitzler

Computer Science and Engineering Faculty Publications

While the stable model semantics, in the form of Answer Set Programming, has become a successful semantics for disjunctive logic programs, a corresponding satisfactory extension of the well-founded semantics to disjunctive programs remains to be found. The many current proposals for such an extension are so diverse, that even a systematic comparison between them is a challenging task. In order to aid the quest for suitable disjunctive well-founded semantics, we present a systematic approach to a comparison based on level mappings, a recently introduced framework for characterizing logic programming semantics, which was quite successfully used for comparing the major semantics …


Interactive Web Portal Application For Ambalta School For Children With Autism, Cathy Talbot Sep 2007

Interactive Web Portal Application For Ambalta School For Children With Autism, Cathy Talbot

Regis University Student Publications (comprehensive collection)

Abalta is a school, based in Galway, designed to educate children who suffer from autism. The school was borne out of the identified need for children with autism to get a specific focused education. In July, 2001, four sets of parents came together, using their own personal funds, to establish the school and had it up and running by September, 2001. It took months of hard work, political negotiating, and lobbying, culminating with a high court case to attain funding from the state. In today's Internet-oriented world, a web application is essential for businesses, organiiations and individuals to optimiie their …


Group Rekeying Schemes For Secure Group Communication In Wireless Sensor Networks, Yong Wang, Byrav Ramamurthy, Yuyan Xue Sep 2007

Group Rekeying Schemes For Secure Group Communication In Wireless Sensor Networks, Yong Wang, Byrav Ramamurthy, Yuyan Xue

School of Computing: Technical Reports

Wireless sensor networks are promising solutions for many applications. However, wireless sensor nodes suffer from many constraints such as low computation capability, small memory, limited energy resources, and so on. Grouping is an important technique to localize computation and reduce communication overhead in wireless sensor networks. In this paper, we use grouping to refer to the process of combining a set of sensor nodes with similar properties. We propose four centralized group rekeying (CGK) schemes for secure group communication in sensor networks. The lifetime of a group is divided into three phases, i.e., group formation, group maintenance, and group dissolution. …


The Effect Of A New Version Of Software On Its Use: A Case Study Of A Course Management System, John Beckett Sep 2007

The Effect Of A New Version Of Software On Its Use: A Case Study Of A Course Management System, John Beckett

Faculty Works

Course Management Systems (CMS) are used to support the growing trend of colleges and universities to offer classes at a distance, and to use technology to provide resources and communication with and for students in traditional classroom settings. Actual use and success of these systems has been mixed in practice, however, for reasons which are not entirely clear.

The theory of Diffusion of Innovations (DOI) described and codified by Everett M. Rogers in 1962 is used to describe how innovations are selected, adopted, and brought to bear on the needs of people with jobs to do. Gary C. Moore and …


An Efficient Scheme For Removing Compromised Sensor Nodes From Wireless Sensor Networks, Yong Wang, Byrav Ramamurthy, Xukai Zou, Yuyan Xue Sep 2007

An Efficient Scheme For Removing Compromised Sensor Nodes From Wireless Sensor Networks, Yong Wang, Byrav Ramamurthy, Xukai Zou, Yuyan Xue

School of Computing: Technical Reports

Key management is a core mechanism to ensure the security of applications and network services in wireless sensor networks. It includes two aspects: key distribution and key revocation. Key distribution has been extensively studied in the context of sensor networks. However, key revocation has received relatively little attention. Existing key revocation schemes can be divided into two categories: centralized key revocation scheme and distributed key revocation scheme. In this paper, we first review and summarize the current key revocation schemes for sensor networks. Then, we present an efficient scheme of removing compromised sensor nodes from wireless sensor networks. Unlike most …


Ukeying: A Key Management Framework For Wireless Sensor Networks Utilizing A Unique Session Key, Yong Wang, Byrav Ramamurthy, Yuyan Xue Sep 2007

Ukeying: A Key Management Framework For Wireless Sensor Networks Utilizing A Unique Session Key, Yong Wang, Byrav Ramamurthy, Yuyan Xue

School of Computing: Technical Reports

Key management is a core mechanism to ensure the security of applications and network services in wireless sensor networks. Key management includes two aspects: key distribution and key revocation. The goal of the key distribution is to establish the required keys between sensor nodes which must exchange data. Key revocation is used to remove compromised sensor nodes from the network. Although many key distribution schemes and key revocation schemes have been proposed in the literature, there is a lack of a framework which can integrate the schemes. In this paper, we propose a key management framework, uKeying, for wireless sensor …


Improving Neural Network Classification Training, Michael Edwin Rimer Sep 2007

Improving Neural Network Classification Training, Michael Edwin Rimer

Theses and Dissertations

The following work presents a new set of general methods for improving neural network accuracy on classification tasks, grouped under the label of classification-based methods. The central theme of these approaches is to provide problem representations and error functions that more directly improve classification accuracy than conventional learning and error functions. The CB1 algorithm attempts to maximize classification accuracy by selectively backpropagating error only on misclassified training patterns. CB2 incorporates a sliding error threshold to the CB1 algorithm, interpolating between the behavior of CB1 and standard error backpropagation as training progresses in order to avoid prematurely saturated network weights. CB3 …


Enabling The Interoperability Of Large-Scale Legacy Systems, Kalyan Moy Gupta, Michael A. Zang, Adam Gray, David W. Aha, Joe Kriege, Jens G. Pohl Sep 2007

Enabling The Interoperability Of Large-Scale Legacy Systems, Kalyan Moy Gupta, Michael A. Zang, Adam Gray, David W. Aha, Joe Kriege, Jens G. Pohl

Collaborative Agent Design (CAD) Research Center

Legacy system data models can interoperate only if their syntactic and semantic differences are resolved. To address this problem, we have developed the Intelligent Mapping Toolkit (IMT), which enables mixed-initiative mapping of meta-data and instances between relational data models. IMT employs a distributed multi-agent architecture so that, unlike many other efforts, it can perform mapping tasks that involve thousands of schema elements. This architecture includes a novel federation of matching agents that leverage case-based reasoning methods. As part of our pre-deployment evaluation for USTRANSCOM and other DoD agencies, we evaluated IMT’s mapping performance and scalability. We show that combinations of …


Dolce Ergo Sumo: On Foundational And Domain Models In Swinto (Smart Web Integrated Ontology), Daniel Oberle, Anupriya Ankolekar, Pascal Hitzler, Philipp Cimiano, Michael Sintek, Malte Kiesel, Babak Mougouie, Stephan Baumann, Shankar Vembu, Massimo Romanelli, Paul Buitelaar, Ralf Engel, Daniel Sonntag, Norbert Reithinger, Berenike Loos, Hans-Peter Zorn, Vanessa Micelli, Robert Porzel, Christian Schmidt, Moritz Weiten, Felix Burkhardt, Jianshen Zhou Sep 2007

Dolce Ergo Sumo: On Foundational And Domain Models In Swinto (Smart Web Integrated Ontology), Daniel Oberle, Anupriya Ankolekar, Pascal Hitzler, Philipp Cimiano, Michael Sintek, Malte Kiesel, Babak Mougouie, Stephan Baumann, Shankar Vembu, Massimo Romanelli, Paul Buitelaar, Ralf Engel, Daniel Sonntag, Norbert Reithinger, Berenike Loos, Hans-Peter Zorn, Vanessa Micelli, Robert Porzel, Christian Schmidt, Moritz Weiten, Felix Burkhardt, Jianshen Zhou

Computer Science and Engineering Faculty Publications

Increased availability of mobile computing, such as personal digital assistants (PDAs), creates the potential for constant and intelligent access to up-to-date, integrated and detailed information from the Web, regardless of one's actual geographical position. Intelligent question-answering requires the representation of knowledge from various domains, such as the navigational and discourse context of the user, potential user questions, the information provided by Web services and so on, for example in the form of ontologies. Within the context of the SmartWeb project, we have developed a number of domain-specific ontologies that are relevant for mobile and intelligent user interfaces to open-domain question-answering …


Toward Automating Ea Configuration: The Parent Selection Stage, Ekaterina Smorodkina, Daniel R. Tauritz Sep 2007

Toward Automating Ea Configuration: The Parent Selection Stage, Ekaterina Smorodkina, Daniel R. Tauritz

Computer Science Faculty Research & Creative Works

One of the obstacles to Evolutionary Algorithms (EAs) fulfilling their promise as easy to use general-purpose problem solvers, is the difficulty of correctly configuring them for specific problems such as to obtain satisfactory performance. Having a mechanism for automatically configuring parameters and operators of every stage of the evolutionary life-cycle would give EAs a more widely spread popularity in the non-expert community. This paper investigates automatic configuration of one of the stages of the evolutionary life-cycle, the parent selection, via a new concept of semi-autonomous parent selection, where mate selection operators are encoded and evolved as in Genetic Programming. We …


Problems With Precision: A Response To “Comments On ‘Data Mining Static Code Attributes To Learn Defect Predictors’”, Tim Menzies, Alex Dekhtyar, Justin Distefano, Jeremy Greenwald Sep 2007

Problems With Precision: A Response To “Comments On ‘Data Mining Static Code Attributes To Learn Defect Predictors’”, Tim Menzies, Alex Dekhtyar, Justin Distefano, Jeremy Greenwald

Computer Science and Software Engineering

Zhang and Zhang argue that predictors are useless unless they have high precison & recall. We have a different view, for two reasons. First, for SE data sets with large neg/pos ratios, it is often required to lower precision to achieve higher recall. Second, there are many domains where low precision detectors are useful.


Any-World Access To Owl From Prolog, Tobias Matzner, Pascal Hitzler Sep 2007

Any-World Access To Owl From Prolog, Tobias Matzner, Pascal Hitzler

Computer Science and Engineering Faculty Publications

The W3C standard OWL provides a decidable language for representing ontologies. While its use is rapidly spreading, efforts are being made by researchers worldwide to augment OWL with additional expressive features or by interlacing it with other forms of knowledge representation, in order to make it applicable for even further purposes. In this paper, we integrate OWL with one of the most successful and most widely used forms of knowledge representation, namely Prolog, and present a hybrid approach which layers Prolog on top of OWL in such a way that the open-world semantics of OWL becomes directly accessible within the …


A Computational Model Of Culture-Specific Conversational Behavior, Dusan Jan, David Herrera, Bilyana Martinovski, David Novick, David Traum Sep 2007

A Computational Model Of Culture-Specific Conversational Behavior, Dusan Jan, David Herrera, Bilyana Martinovski, David Novick, David Traum

Selected Works Temporary Series

This paper presents a model for simulating cultural differences in the conversational behavior of virtual agents. The model provides parameters for differences in proxemics, gaze and overlap in turn taking.We present a review of literature on these factors and show results of a study where native speakers of Nrth American English, Mexican Spanish and Arabic were asked to rate the realism of the simulations generated based on different cultural parameters with respect to their culture.


The Programmable Web: Agile, Social, And Grassroots Computing, E. Michael Maximilien, Ajith Harshana Ranabahu Sep 2007

The Programmable Web: Agile, Social, And Grassroots Computing, E. Michael Maximilien, Ajith Harshana Ranabahu

Kno.e.sis Publications

Web services, the semantic Web, and Web 2.0 are three somewhat separate movements trying to make the Web a programmable substrate. While each has achieved some level of success on their own right, it is becoming apparent that the grassroots approach of the Web 2.0 is gaining greater success than the other two. In this paper we analyze each movement, briefly describing its main traits, and outlining its primary assumptions. We then frame the common problem of achieving a programmable Web within the context of distributed computing and software engineering and then attempt to show why Web 2.0 is closest …


Shibboleth As A Tool For Authorized Access Control To The Subversion Repository System, Amy Apon, Linh B. Ngo Sep 2007

Shibboleth As A Tool For Authorized Access Control To The Subversion Repository System, Amy Apon, Linh B. Ngo

Publications

Shibboleth is an architecture and protocol for allowing users to authenticate and be authorized to use a remote resource by logging into the identity management system that is maintained at their home institution. With Shibboleth, a federation of institutions can share resources among users and yet allow the administration of both the user access control to resources and the user identity and attribute information to be performed at the hosting or home institution. Subversion is a version control repository system that allows the creation of fine-grained permissions to files and directories. In this project an infrastructure, Shibbolized Subversion, has been …


Shibboleth As A Tool For Authorized Access Control To The Subversion Repository System, Linh B. Ngo, Amy W. Apon Sep 2007

Shibboleth As A Tool For Authorized Access Control To The Subversion Repository System, Linh B. Ngo, Amy W. Apon

Publications

Shibboleth is an architecture and protocol for allowing users to authenticate and be authorized to use a remote resource by logging into the identity management system that is maintained at their home institution. With Shibboleth, a federation of institutions can share resources among users and yet allow the administration of both the user access control to resources and the user identity and attribute information to be performed at the hosting or home institution. Subversion is a version control repository system that allows the creation of fine-grained permissions to files and directories. In this project an infrastructure, Shibbolized Subversion, has been …


Variable Neighbor Selection In Live Peer-To-Peer Multimedia Streaming Networks, Jagannath Ghoshal, Byrav Ramamurthy, Lisong Xu Sep 2007

Variable Neighbor Selection In Live Peer-To-Peer Multimedia Streaming Networks, Jagannath Ghoshal, Byrav Ramamurthy, Lisong Xu

School of Computing: Technical Reports

Data-driven (or swarming based) streaming is one of the popular ways to distribute multimedia streaming traffic over live Peer-to-Peer (P2P) networks. In data-driven streaming networks, each peer independently selects its neighbors based on gossip-style overlay construction and then exchanges streaming data with the neighbors using data scheduling. In a P2P network the major advantage is that each peer contributes its own resources to the network. As a result, there is an increase in the amount of overall resources of the network, such as bandwidth, storage space, and computing power. However such type of networks exhibit end user bandwidth heterogeneity. Consequently, …


Sa-Rest And (S)Mashups: Adding Semantics To Restful Services, Jonathan Lathem, Karthik Gomadam, Amit P. Sheth Sep 2007

Sa-Rest And (S)Mashups: Adding Semantics To Restful Services, Jonathan Lathem, Karthik Gomadam, Amit P. Sheth

Kno.e.sis Publications

The evolution of the Web 2.0 phenomenon has led to the increased adoption of the RESTful services paradigm. RESTful services often take the form of RSS/Atom feeds and AJAX based light weight services. The XML based messaging paradigm of RESTful services has made it possible to compose various services together. Such compositions of RESTful services is widely referred to as Mashups. In this paper, we outline the limitations in current approaches to creating mashups. We address these limitations by proposing a framework called as SA-REST. SA-REST adds semantics to RESTful services. Our proposed framework builds upon the original ideas in …


Rushes Video Summarization By Object And Event Understanding, Feng Wang, Chong-Wah Ngo Sep 2007

Rushes Video Summarization By Object And Event Understanding, Feng Wang, Chong-Wah Ngo

Research Collection School Of Computing and Information Systems

This paper explores a variety of visual and audio analysis techniques in selecting the most representative video clips for rushes summarization at TRECVID 2007. These techniques include object detection, camera motion estimation, keypoint matching and tracking, audio classification and speech recognition. Our system is composed of two major steps. First, based on video structuring, we filter undesirable shots and minimize the inter-shot redundancy by repetitive shot detection. Second, a representability measure is proposed to model the presence of objects and four audio-visual events: motion activity of objects, camera motion, scene changes, and speech content, in a video clip. The video …


Who’S Creating?, M. Thulasidas Sep 2007

Who’S Creating?, M. Thulasidas

Research Collection School Of Computing and Information Systems

We don’t read to retain information or knowledge any more. We search, scan, locate keywords, browse and bookmark. The Internet is doing to our reading habits what the calculator did to our arithmetic abilities. Knowledge is not cheap, although our easy access to it through the Internet may indicate otherwise. When we all become users of information, our knowledge will stop at its current level because nobody will be creating it any more.


Parallelization Of Ant Colony Optimization Via Area Of Expertise Learning, Adrian A. De Freitas Sep 2007

Parallelization Of Ant Colony Optimization Via Area Of Expertise Learning, Adrian A. De Freitas

Theses and Dissertations

Ant colony optimization algorithms have long been touted as providing an effective and efficient means of generating high quality solutions to NP-hard optimization problems. Unfortunately, while the structure of the algorithm is easy to parallelize, the nature and amount of communication required for parallel execution has meant that parallel implementations developed suffer from decreased solution quality, slower runtime performance, or both. This thesis explores a new strategy for ant colony parallelization that involves Area of Expertise (AOE) learning. The AOE concept is based on the idea that individual agents tend to gain knowledge of different areas of the search space …


Multi-Objective Optimization For Speed And Stability Of A Sony Aibo Gait, Christopher A. Patterson Sep 2007

Multi-Objective Optimization For Speed And Stability Of A Sony Aibo Gait, Christopher A. Patterson

Theses and Dissertations

Locomotion is a fundamental facet of mobile robotics that many higher level aspects rely on. However, this is not a simple problem for legged robots with many degrees of freedom. For this reason, machine learning techniques have been applied to the domain. Although impressive results have been achieved, there remains a fundamental problem with using most machine learning methods. The learning algorithms usually require a large dataset which is prohibitively hard to collect on an actual robot. Further, learning in simulation has had limited success transitioning to the real world. Also, many learning algorithms optimize for a single fitness function, …


Video Stabilization And Enhancement, Hany Farid, Jeffrey B. Woodward Sep 2007

Video Stabilization And Enhancement, Hany Farid, Jeffrey B. Woodward

Computer Science Technical Reports

We describe a simple and computationally efficient approach for video stabilization and enhancement. By combining multiple low-quality video frames, it is possible to extract a high-quality still image. This technique is particularly helpful in identifying people, license plates, etc. from low-quality video surveillance cameras.


Evaluating Opportunistic Routing Protocols With Large Realistic Contact Traces, Libo Song, David Kotz Sep 2007

Evaluating Opportunistic Routing Protocols With Large Realistic Contact Traces, Libo Song, David Kotz

Dartmouth Scholarship

Traditional mobile ad hoc network (MANET) routing protocols assume that contemporaneous end-to-end communication paths exist between data senders and receivers. In some mobile ad hoc networks with a sparse node population, an end-to-end communication path may break frequently or may not exist at any time. Many routing protocols have been proposed in the literature to address the problem, but few were evaluated in a realistic “opportunistic” network setting. We use simulation and contact traces (derived from logs in a production network) to evaluate and compare five existing protocols: direct-delivery, epidemic, random, PRoPHET, and Link-State, as well as our own proposed …


A Survey Of Schema Matching Research, Roger Blake Sep 2007

A Survey Of Schema Matching Research, Roger Blake

College of Management Working Papers and Reports

Schema matching is the process of developing semantic matches between two or more schemas. The purpose of schema matching is generally either to merge two or more databases, or to enable queries on multiple, heterogeneous databases to be formulated on a single schema (Doan and Halevy 2005). This paper develops a taxonomy of schema matching approaches, classifying them as being based on a combination schema matching technique and the type of data used by those techniques. Schema matching techniques are categorized as being based on rules, learning, or ontology, and the type of data used is categorized as being based …


Reliability Modeling For The Advanced Electric Power Grid, Ayman Z. Faza, Sahra Sedigh, Bruce M. Mcmillin Sep 2007

Reliability Modeling For The Advanced Electric Power Grid, Ayman Z. Faza, Sahra Sedigh, Bruce M. Mcmillin

Electrical and Computer Engineering Faculty Research & Creative Works

The advanced electric power grid promises a self-healing infrastructure using distributed, coordinated, power electronics control. One promising power electronics device, the Flexible AC Transmission System (FACTS), can modify power flow locally within a grid. Embedded computers within the FACTS devices, along with the links connecting them, form a communication and control network that can dynamically change the power grid to achieve higher dependability. The goal is to reroute power in the event of transmission line failure. Such a system, over a widespread area, is a cyber-physical system. The overall reliability of the grid is a function of the respective reliabilities …


Temporal Factors To Evaluate Trustworthiness Of Virtual Identities, Luca Longo, Pierpaolo Dondio, Stephen Barrett Sep 2007

Temporal Factors To Evaluate Trustworthiness Of Virtual Identities, Luca Longo, Pierpaolo Dondio, Stephen Barrett

Conference papers

In this paper we investigate how temporal factors (i.e. factors computed by considering only the time-distribution of interactions) can be used as an evidence of an entity’s trustworthiness. While reputation and direct experience are the two most widely used sources of trust in applications, we believe that new sources of evidence and new applications should be investigated [1]. Moreover, while these two classical techniques are based on evaluating the outcomes of interactions (direct or indirect), temporal factors are based on quantitative analysis, representing an alternative way of assessing trust. Our presumption is that, even with this limited information, temporal factors …


Globally Distributed Software Development Project Performance: An Empirical Analysis, Narayanasamy Ramasubbu, Rajesh Krishna Balan Sep 2007

Globally Distributed Software Development Project Performance: An Empirical Analysis, Narayanasamy Ramasubbu, Rajesh Krishna Balan

Research Collection School Of Computing and Information Systems

Software firms are increasingly distributing their software development effort across multiple locations. In this paper we present the results of a two year field study that investigated the effects of dispersion on the productivity and quality of distributed software development. We first develop a model of distributed software development. We then use the model, along with our empirically observed data, to understand the consequences of dispersion on software project performance. Our analysis reveals that, even in high process maturity environments, a) dispersion significantly reduces development productivity and has effects on conformance quality, and b) these negative effects of dispersion can …


Scaling Ant Colony Optimization With Hierarchical Reinforcement Learning Partitioning, Erik J. Dries Sep 2007

Scaling Ant Colony Optimization With Hierarchical Reinforcement Learning Partitioning, Erik J. Dries

Theses and Dissertations

This research merges the hierarchical reinforcement learning (HRL) domain and the ant colony optimization (ACO) domain. The merger produces a HRL ACO algorithm capable of generating solutions for both domains. This research also provides two specific implementations of the new algorithm: the first a modification to Dietterich's MAXQ-Q HRL algorithm, the second a hierarchical ACO algorithm. These implementations generate faster results, with little to no significant change in the quality of solutions for the tested problem domains. The application of ACO to the MAXQ-Q algorithm replaces the reinforcement learning, Q-learning and SARSA, with the modified ant colony optimization method, Ant-Q. …


Collaborative, Trust-Based Security Mechanisms For A National Utility Intranet, Gregory M. Coates Sep 2007

Collaborative, Trust-Based Security Mechanisms For A National Utility Intranet, Gregory M. Coates

Theses and Dissertations

This thesis investigates security mechanisms for utility control and protection networks using IP-based protocol interaction. It proposes flexible, cost-effective solutions in strategic locations to protect transitioning legacy and full IP-standards architectures. It also demonstrates how operational signatures can be defined to enact organizationally-unique standard operating procedures for zero failure in environments with varying levels of uncertainty and trust. The research evaluates layering encryption, authentication, traffic filtering, content checks, and event correlation mechanisms over time-critical primary and backup control/protection signaling to prevent disruption by internal and external malicious activity or errors. Finally, it shows how a regional/national implementation can protect private …