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Rcu Semantics: A First Attempt, Paul E. Mckenney, Jonathan Walpole Jan 2005

Rcu Semantics: A First Attempt, Paul E. Mckenney, Jonathan Walpole

Computer Science Faculty Publications and Presentations

There is not yet a formal statement of RCU (read-copy update) semantics. While this lack has thus far not been an impediment to adoption and use of RCU, it is quite possible that formal semantics would point the way towards tools that automatically validate uses of RCU or that permit RCU algorithms to be automatically generated by a parallel compiler. This paper is a first attempt to supply a formal definition of RCU. Or at least a semi-formal definition: although RCU does not yet wear a tux (though it does run in Linux), at least it might yet wear some …

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An Empirical Study Of Imputation Techniques For Software Data Sets, Sumanth Yenduri Jan 2005

An Empirical Study Of Imputation Techniques For Software Data Sets, Sumanth Yenduri

LSU Doctoral Dissertations

Software Project Effort/Cost/Time Estimation has been one of the hot topics of research in the current software engineering industry. Solutions for effort/cost/time estimation are in great demand. Knowledge of accurate effort/cost/time estimates early in the software project life cycle enables project managers manage and exploit resources efficiently. The constraints of cost and time can also be met. To this day, most companies rely on their historical database of past project data sets to predict estimates for future projects. Like other data sets, software project data sets also suffer from numerous problems. The most important problem is they contain missing/incomplete data. …

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Efficient Automatic Correction And Segmentation Based 3d Visualization Of Magnetic Resonance Images, Mikhail V. Milchenko Jan 2005

Efficient Automatic Correction And Segmentation Based 3d Visualization Of Magnetic Resonance Images, Mikhail V. Milchenko

LSU Doctoral Dissertations

In the recent years, the demand for automated processing techniques for digital medical image volumes has increased substantially. Existing algorithms, however, still often require manual interaction, and newly developed automated techniques are often intended for a narrow segment of processing needs. The goal of this research was to develop algorithms suitable for fast and effective correction and advanced visualization of digital MR image volumes with minimal human operator interaction. This research has resulted in a number of techniques for automated processing of MR image volumes, including a novel MR inhomogeneity correction algorithm derivative surface fitting (dsf), automatic tissue detection algorithm …

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Broadcast In Sparse Conversion Optical Networks Using Fewest Converters, Tong Yi Jan 2005

Broadcast In Sparse Conversion Optical Networks Using Fewest Converters, Tong Yi

LSU Doctoral Dissertations

Wavelengths and converters are shared by communication requests in optical networks. When a message goes through a node without a converter, the outgoing wavelength must be the same as the incoming one. This constraint can be removed if the node uses a converter. Hence, the usage of converters increases the utilization of wavelengths and allows more communication requests to succeed. Since converters are expensive, we consider sparse conversion networks, where only some specified nodes have converters. Moreover, since the usage of converters induces delays, we should minimize the use of available converters. The Converters Usage Problem (CUP) is to use …

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Biologically Inspired Learning System, Patrick Mcdowell Jan 2005

Biologically Inspired Learning System, Patrick Mcdowell

LSU Doctoral Dissertations

Learning Systems used on robots require either a-priori knowledge in the form of models, rules of thumb or databases or require that robot to physically execute multitudes of trial solutions. The first requirement limits the robot’s ability to operate in unstructured changing environments, and the second limits the robot’s service life and resources. In this research a generalized approach to learning was developed through a series of algorithms that can be used for construction of behaviors that are able to cope with unstructured environments through adaptation of both internal parameters and system structure as a result of a goal based …

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Medical Image Enhancement, Alina Monica Trifas Jan 2005

Medical Image Enhancement, Alina Monica Trifas

LSU Doctoral Dissertations

Each image acquired from a medical imaging system is often part of a two-dimensional (2-D) image set whose total presents a three-dimensional (3-D) object for diagnosis. Unfortunately, sometimes these images are of poor quality. These distortions cause an inadequate object-of-interest presentation, which can result in inaccurate image analysis. Blurring is considered a serious problem. Therefore, “deblurring” an image to obtain better quality is an important issue in medical image processing. In our research, the image is initially decomposed. Contrast improvement is achieved by modifying the coefficients obtained from the decomposed image. Small coefficient values represent subtle details and are amplified …

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Automatic Segmentation Of Magnetic Resonance Images Of The Brain, Kirk V. N. Spence Jan 2005

Automatic Segmentation Of Magnetic Resonance Images Of The Brain, Kirk V. N. Spence

LSU Doctoral Dissertations

Magnetic resonance imaging (MRI) is a technique used primarily in medical settings to produce high quality images of the human body’s internal anatomy. Each image is of a thin slice through the body, with the typical distance between slices being a few millimeters. Brain segmentation is the delineation of one or more anatomical structures within images of the brain. It promotes greater understanding of spatial relationships to aid in such tasks as surgical planning and clinical diagnoses, particularly when the segmented outlines from each image slice are displayed together as a surface in three-dimensions. A review of the literature indicates …

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Adaptive Remote Visualization System With Optimized Network Performance For Large Scale Scientific Data, Mengxia Zhu Jan 2005

Adaptive Remote Visualization System With Optimized Network Performance For Large Scale Scientific Data, Mengxia Zhu

LSU Doctoral Dissertations

This dissertation discusses algorithmic and implementation aspects of an automatically configurable remote visualization system, which optimally decomposes and adaptively maps the visualization pipeline to a wide-area network. The first node typically serves as a data server that generates or stores raw data sets and a remote client resides on the last node equipped with a display device ranging from a personal desktop to a powerwall. Intermediate nodes can be located anywhere on the network and often include workstations, clusters, or custom rendering engines. We employ a regression model-based network daemon to estimate the effective bandwidth and minimal delay of a …

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Learning Discrete Hidden Markov Models From State Distribution Vectors, Luis G. Moscovich Jan 2005

Learning Discrete Hidden Markov Models From State Distribution Vectors, Luis G. Moscovich

LSU Doctoral Dissertations

Hidden Markov Models (HMMs) are probabilistic models that have been widely applied to a number of fields since their inception in the late 1960’s. Computational Biology, Image Processing, and Signal Processing, are but a few of the application areas of HMMs. In this dissertation, we develop several new efficient learning algorithms for learning HMM parameters. First, we propose a new polynomial-time algorithm for supervised learning of the parameters of a first order HMM from a state probability distribution (SD) oracle. The SD oracle provides the learner with the state distribution vector corresponding to a query string. We prove the correctness …

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Radio Resource Management For Cellular Wireless Local Area Networks., Olivia Brickley Jan 2005

Radio Resource Management For Cellular Wireless Local Area Networks., Olivia Brickley

Theses

The growing demand for mobile computing worldwide has led to the increasing deployment and use of Wireless Local Area Networks (WLANs) in the last number of years. During this time, user requirements have evolved, resulting in a more diverse mix of services being carried over the wireless medium. In particular, delay sensitive real-time applications such as streaming multimedia and voice over IP are growing in importance. The widely accepted IEEE 802.11b standard, however, was not designed with sufficient Quality of Service (QoS) constraints for such applications. A new draft of the standard named 802.1 le has been proposed that deals …

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Opto-Vlsi Processing For Reconfigurable Optical Devices, Chung-Kiak Poh Jan 2005

Opto-Vlsi Processing For Reconfigurable Optical Devices, Chung-Kiak Poh

Theses: Doctorates and Masters

The implementation of Wavelength Division Multiplexing system (WDM) optical fibre transmission systems has the potential to realise this high capacity data rate exceeding 10 Tb/s. The ability to reconfigure optical networks is a desirable attribute for future metro applications where light paths can be set up or taken down dynamically as required in the network. The use of microelectronics in conjunction with photonics enables intelligence to be added to the high-speed capability of photonics, thus realising reconfigurable optical devices which can revolutionise optical telecommunications and many more application areas. In this thesis, we investigate and demonstrate the capability of Opto-VLSI …

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The Pedagogical And Practical Issues Of Using Ict In Post-Primary Schools, Kay O'Sullivan Mc Carty Jan 2005

The Pedagogical And Practical Issues Of Using Ict In Post-Primary Schools, Kay O'Sullivan Mc Carty

Theses

This study was an investigation into some of the pedagogical and practical issues that need to be considered when using ICT, with particular reference to post-primary schools. This investigation was prompted by the introduction of broadband into Irish schools in the next twelve months. Resources need to be developed that are subject specific and relevant to the Irish curriculum. The principle learning theories were examined and their pedagogical implications for post-primary teachers were discussed. The definition of learning styles was explored, different measurements were looked at and several internet based inventories were examined. The VARK questionnaire was administered to a …

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A Context-Dependent Model Of Proximity In Physically Situated Environments, John D. Kelleher, Geert-Jan M. Kruijff Jan 2005

A Context-Dependent Model Of Proximity In Physically Situated Environments, John D. Kelleher, Geert-Jan M. Kruijff

Conference papers

The paper presents a computational model for a context-dependent analysis of a physical environment in terms of spatial proximity. The model provides a basis for grounding linguistic analyses of spatial expressions in visual perception. The model uses potential fields to model spatial proximity. It has been implemented, and when combined with a handcrafted grammar, is used to enable a conversational robot to carry out a situated dialogue with a human. The key concept in our approach is defining the region that is proximal to a landmark based on the spatial configuration of other objects in the scene. The model extends …

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Maintaining The Identity Of Dynamically Embodied Agents, Alan Martin, Gregory O'Hare, Brian Duffy, Bianca Schoen-Phelan, John Bradley Jan 2005

Maintaining The Identity Of Dynamically Embodied Agents, Alan Martin, Gregory O'Hare, Brian Duffy, Bianca Schoen-Phelan, John Bradley

Conference papers

Virtual agents are traditionally constrained in their embod- iment, as they are restricted to one form of body. We propose allowing them to change their embodiment in order to expand their capabili- ties. This presents users with a number of di±culties in maintaining the identity of the agents, but these can be overcome by using identity cues, certain features that remain constant across embodiment forms. This pa- per outlines an experiment that examines these identity cues, and shows that they can be used to help address this identity problem.

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Intentional Embodied Agents, Alan Martin, Gregory M.P. O'Hare, Brian R. Duffy, John F. Bradley, Bianca Schoen-Phelan Jan 2005

Intentional Embodied Agents, Alan Martin, Gregory M.P. O'Hare, Brian R. Duffy, John F. Bradley, Bianca Schoen-Phelan

Conference papers

The notion of embodiment within a virtual environment and an intelligent agent could be intimately linked, in order to form a single Agent Chameleon. This paper presents an architecture for achieving this, while allowing agents freedom to chose an embodiment suitable to the task at hand..

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The Amphere Algorithm: Area Masking With The Performance Equation, Bianca Schoen-Phelan, Gregory O'Hare, Brian Duffy, Alan Martin, John Bradley Jan 2005

The Amphere Algorithm: Area Masking With The Performance Equation, Bianca Schoen-Phelan, Gregory O'Hare, Brian Duffy, Alan Martin, John Bradley

Conference papers

This paper is concerned with the employment of an autonomous and intelligent agent within the context of a 3-dimensional virtual environment. As the agent is immersed within the virtual environment, it empowers the 3D world with mechanisms to adjust itself to the specific needs of its user. Therefore, the agent serves as a middle layer between user and the environment. The 3-dimensional environment thus evolved into an intelligent user interface. We track user’s motion within this environment and present an equation upon which the agent classifies the user’s performance. Based upon this performance value, the agent autonomously determines if the …

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Bi-Directional Ontology Versioning Bov, Siyang Zhao, Brendan Tierney Jan 2005

Bi-Directional Ontology Versioning Bov, Siyang Zhao, Brendan Tierney

Conference papers

his paper defines a new type of ontology versioning: Bi-directional Ontology Versioning: BOV. BOV provides bi-directional mappings and transformations between concepts in two ontology versions. BOV is identified by two levels mapping processes: linguistic mapping and structural mapping. BOV can satisfy the requirement of mapping in distributed environment.

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Protecting The Communication Structure In Sensor Networks, S. Olariu, Q. Xu, M. Eltoweissy, A. Wadaa Jan 2005

Protecting The Communication Structure In Sensor Networks, S. Olariu, Q. Xu, M. Eltoweissy, A. Wadaa

Computer Science Faculty Publications

In the near future wireless sensor networks will be employed in a wide variety of applications establishing ubiquitous networks that will pervade society. The inherent vulnerability of these massively deployed networks to a multitude of threats, including physical tampering with nodes exacerbates concerns about privacy and security. For example, denial of service attacks (DoS) that compromise or disrupt communications or target nodes serving key roles in the network, e.g. sink nodes, can easily undermine the functionality as well as the performance delivered by the network. Particularly vulnerable are the components of the communications or operation infrastructure. Although, by construction, most …

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Final Report For The Development Of The Nasa Technical Report Server (Ntrs), Michael L. Nelson Jan 2005

Final Report For The Development Of The Nasa Technical Report Server (Ntrs), Michael L. Nelson

Computer Science Faculty Publications

The author performed a variety of research, development and consulting tasks for NASA Langley Research Center in the area of digital libraries (DLs) and supporting technologies, such as the Open Archives Initiative Protocol for Metadata Harvesting (OAI-PMH). In particular, the development focused on the NASA Technical Report Server (NTRS) and its transition from a distributed searching model to one that uses the OAI-PMH. The Open Archives Initiative (OAI) is an international consortium focused on furthering the interoperability of DLs through the use of "metadata harvesting". The OAI-PMH version of NTRS went into public production on April 28, 2003. Since that …

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Archive Ingest And Handling Test, Michael L. Nelson, Johan Bollen, Giridhar Manepalli, Rabia Haq Jan 2005

Archive Ingest And Handling Test, Michael L. Nelson, Johan Bollen, Giridhar Manepalli, Rabia Haq

Computer Science Faculty Publications

The Archive Ingest and Handling Test (AIHT) was a Library of Congress (LC) sponsored research project administered by Information Systems and Support Inc. (ISS). The project featured five participants: Old Dominion University Computer Science Department; Harvard University Library; Johns Hopkins University Library; Stanford University Library; Library of Congress. All five participants received identical disk drives containing copies of the 911.gmu.edu web site, a collection of 9/11 materials maintained by George Mason University (GMU). The purpose of the AIHT experiment was to perform archival forensics to determine the nature of the archive, ingest it, simulate at least one of the file …

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Introduction: Data Communication And Topology Algorithms For Sensor Networks, Stephan Olariu, David Simplot-Ryl, Ivan Stojmenovic Jan 2005

Introduction: Data Communication And Topology Algorithms For Sensor Networks, Stephan Olariu, David Simplot-Ryl, Ivan Stojmenovic

Computer Science Faculty Publications

(First paragraph) We are very proud and honored to have been entrusted to be Guest Editors for this special issue. Papers were sought to comprehensively cover the algorithmic issues in the “hot” area of sensor networking. The concentration was on network layer problems, which can be divided into two groups: data communication problems and topology control problems. We wish to briefly introduce the five papers appearing in this special issue. They cover specific problems such as time division for reduced collision, fault tolerant clustering, self-stabilizing graph optimization algorithms, key pre-distribution for secure communication, and distributed storage based on spanning trees …

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Computer Security: Investigating The Impact That Security Specific Education Has On Users’ Behaviour, Samuel David Jones Jan 2005

Computer Security: Investigating The Impact That Security Specific Education Has On Users’ Behaviour, Samuel David Jones

Theses : Honours

A lack in end-user awareness in computer security issues provides the rationale for this investigation. The research considers whether or not the provision of an educational package addressing computer security issues will improve awareness and transform behaviour of end-users in assessing and enacting appropriate responses in computer security situations. A group of twenty participants was studied in detail using a mixed methods research approach. The participants were drawn from a cross section of computer end-users, from elementary to advanced levels of computer literacy. Outcomes include a positive response to the provision of material, however human factors were found to be …

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Artificial Neural Networks : A Comparative Study Of Implementations For Human Chromosome Classification, Nancy Akl Jan 2005

Artificial Neural Networks : A Comparative Study Of Implementations For Human Chromosome Classification, Nancy Akl

Theses : Honours

Artificial neural networks are a popular field of artificial intelligence and have commonly been applied to solve many prediction, classification and diagnostic tasks. One such task is the analysis of human chromosomes. This thesis investigates the use of artificial neural networks (ANNs) as automated chromosome classifiers. The investigation involves the thorough analysis of seven different implementation techniques. These include three techniques using artificial neural networks, two techniques using ANN s supported by another method and two techniques not using ANNs. These seven implementations are evaluated according to the classification accuracy achieved and according to their support of important system measures, …

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End User Preference Of Customisable Features Within A Course Management System, Diana Taylor Jan 2005

End User Preference Of Customisable Features Within A Course Management System, Diana Taylor

Theses : Honours

Customisation is the means by which people alter and change various elements of their environment with the purpose of making it more suited to their immediate needs. This aids in creating a more personalised experience. People are extremely diverse in terms of age, gender, nationality, and with the dominant presence of technology people also have various levels of computer skills and experience. In the context of computer environments, customisation provides the ability to cater for a diverse user group, providing tools and options that assist with specific tasks, improve accessibility and achieve greater user satisfaction. Carter, MacLean, Lovstard & Moran …

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Towards Persistent Resource Identification With The Uniform Resource Name, Luke Brown Jan 2005

Towards Persistent Resource Identification With The Uniform Resource Name, Luke Brown

Theses : Honours

The exponential growth of the Internet, and the subsequent reliance on the resources it connects, has exposed a clear need for an Internet identifier which remains accessible over time. Such identifiers have been dubbed persistent identifiers owing to the promise of reliability they imply. Persistent naming systems exist at present, however it is the resolution of these systems into what Kunze, (2003) calls "persistent actionable identifiers" which is the focus of this work. Actionable identifiers can be thought of as identifiers which are accessible in a simple fashion such as through a web browser or through a specific application. This …

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An Investigation Of Network Security Management Methods, Shamila Anuranga Ratnayake Jan 2005

An Investigation Of Network Security Management Methods, Shamila Anuranga Ratnayake

Theses : Honours

Network Management (NM) is concerned with reducing complexity and managing cost. The traditional NM tools and techniques are based on the Open System Interconnection (OSI) NM model. However, several drawbacks have been identified when managing a network using traditional NM tools (Sarkar & Verma, 2001). Network security is a major issue when managing a network. Even though the technology assists to reduce security risks, unless properly managed, the security measures may not do the job as expected. The State Model (SM) diagram is a new method, which may assists in managing the network. This new method may provide functionality not …

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2d-Barcode For Mobile Devices, Hiroko Kato Jan 2005

2d-Barcode For Mobile Devices, Hiroko Kato

Theses : Honours

2D-barcodes were designed to carry significantly more data than its 1D counterpart. These codes are often used in industrial information tagging applications where high data capacity, mobility, and data robustness are required. Wireless mobile devices such as camera phones and Portable Digital Assistants (PDAs) have evolved from just a mobile voice communication device to what is now a mobile multimedia computing platform. Recent integration of these two mobile technologies has sparked some interesting applications where 2D-barcodes work as visual tags and/or information source and camera phones performs image processing tasks on the device itself. One of such applications is hyperlink …

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View Space Linking, Solid Node Compression And Binary Space Partitioning For Visibility Determination In 3d Walk-Throughs, Joel Anderson Jan 2005

View Space Linking, Solid Node Compression And Binary Space Partitioning For Visibility Determination In 3d Walk-Throughs, Joel Anderson

Theses : Honours

Today's 3D games consumers are expecting more and more quality in their games. To enable high quality graphics at interactive rates, games programmers employ a technique known as hidden surface removal (HSR) or polygon culling. HSR is not just applicable to games; it may also be applied to any application that requires quality and interactive rates, including medical, military and building applications. One such commonly used technique for HSR is the binary space partition (BSP) tree, which is used for 3D ‘walk-throughs’, otherwise known as 3D static environments or first person shooters. Recent developments in 3D accelerated hardware technology do …

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Lessons Learned With Arc, An Oai-Pmh Service Provider, Xiaoming Liu, Kurt Maly, Michael L. Nelson Jan 2005

Lessons Learned With Arc, An Oai-Pmh Service Provider, Xiaoming Liu, Kurt Maly, Michael L. Nelson

Computer Science Faculty Publications

Web-based digital libraries have historically been built in isolation utilizing different technologies, protocols, and metadata. These differences hindered the development of digital library services that enable users to discover information from multiple libraries through a single unified interface. The Open Archives Initiative Protocol for Metadata Harvesting (OAI-PMH) is a major, international effort to address technical interoperability among distributed repositories. Arc debuted in 2000 as the first end-user OAI-PMH service provider. Since that time, Arc has grown to include nearly 7,000,000 metadata records. Arc has been deployed in a number of environments and has served as the basis for many other …

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Weak Factorizations, Fractions And Homotopies, Alexander Kurz, Jiří Rosický Jan 2005

Weak Factorizations, Fractions And Homotopies, Alexander Kurz, Jiří Rosický

Engineering Faculty Articles and Research

We show that the homotopy category can be assigned to any category equipped with a weak factorization system. A classical example of this construction is the stable category of modules. We discuss a connection with the open map approach to bisimulations proposed by Joyal, Nielsen and Winskel.

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