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Discontinuous Waveband Switching In Wdm Optical Networks, Bhavana Lekkala, Byrav Ramamurthy Jan 2005

Discontinuous Waveband Switching In Wdm Optical Networks, Bhavana Lekkala, Byrav Ramamurthy

School of Computing: Conference and Workshop Papers

Routing techniques used in wavelength routed optical networks (WRN) do not give an efficient solution with Waveband routed optical networks (WBN) as the objective of routing in WRN is to reduce the blocking probability and that in WBN is to reduce the number of switching ports. Routing in WBN can be divided two parts, finding the route and grouping the wavelength assigned into that route with some existing wavelengths/wavebands. In this paper, we propose a heuristic for waveband routing, which uses a new grouping strategy called discontinuous waveband grouping to group the wavelengths into a waveband. The main objective of …

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Performance Analysis Of Sparse Traffic Grooming In Wdm Mesh Networks, Wang Yao, Mengke Li, Byrav Ramamurthy Jan 2005

Performance Analysis Of Sparse Traffic Grooming In Wdm Mesh Networks, Wang Yao, Mengke Li, Byrav Ramamurthy

School of Computing: Conference and Workshop Papers

Sparse traffic grooming is a practical problem to be addressed in heterogeneous multi-vendor optical WDM networks where only some of the optical cross-connects (OXCs) have grooming capabilities. Such a network is called as a sparse grooming network. The sparse grooming problem under dynamic traffic in optical WDM mesh networks is a relatively unexplored problem. In this work, we propose the maximize-lightpath-sharing multi-hop (MLS-MH) grooming algorithm to support dynamic traffic grooming in sparse grooming networks. We also present an analytical model to evaluate the blocking performance of the MLS-MH algorithm. Simulation results show that MLSMH outperforms an existing grooming algorithm, the …

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Utilizing Device Slack For Energy-Efficient I/O Device Scheduling In Hard Real-Time Systems With Non-Preemptible Resources, Hui Cheng, Steve Goddard Jan 2005

Utilizing Device Slack For Energy-Efficient I/O Device Scheduling In Hard Real-Time Systems With Non-Preemptible Resources, Hui Cheng, Steve Goddard

School of Computing: Technical Reports

The challenge in conserving energy in embedded real-time systems is to reduce power consumption while preserving temporal correctness. Much research has focused on power conservation for the processor, while power conservation for I/O devices has received little attention. In this paper, we analyze the problem of online energy-aware I/O scheduling for hard real-time systems based on the preemptive periodic task model with non-preemptible shared resources. We extend the concept of device slack proposed in [2] to support non-preemptible shared resources; and propose an online energy-aware I/O scheduling algorithm: Energy-efficient Device Scheduling with Non-preemptible Resources (EEDS NR). The EEDS NR algorithm …

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Network Intrusion Detection: Monitoring, Simulation And Visualization, Mian Zhou Jan 2005

Network Intrusion Detection: Monitoring, Simulation And Visualization, Mian Zhou

Electronic Theses and Dissertations

This dissertation presents our work on network intrusion detection and intrusion sim- ulation. The work in intrusion detection consists of two different network anomaly-based approaches. The work in intrusion simulation introduces a model using explicit traffic gen- eration for the packet level traffic simulation. The process of anomaly detection is to first build profiles for the normal network activity and then mark any events or activities that deviate from the normal profiles as suspicious. Based on the different schemes of creating the normal activity profiles, we introduce two approaches for intrusion detection. The first one is a frequency-based approach which …

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Isram: Information Security Risk Analysis Method, Bilge Karabacak, Ibrahim Sogukpinar Jan 2005

Isram: Information Security Risk Analysis Method, Bilge Karabacak, Ibrahim Sogukpinar

All Faculty and Staff Scholarship

Continuously changing nature of technological environment has been enforcing to revise the process of information security risk analysis accordingly. A number of quantitative and qualitative risk analysis methods have been proposed by researchers and vendors. The purpose of these methods is to analyze today's information security risks properly. Some of these methods are supported by a software package. In this study, a survey based quantitative approach is proposed to analyze security risks of information technologies by taking current necessities into consideration. The new method is named as Information Security Risk Analysis Method (ISRAM). Case study has shown that ISRAM yields …

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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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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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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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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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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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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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Performance Analysis And Validation Of A Recoverable Flight Control System In A Simulated Neutron Environment, Hong Zhang, W. Steven Gray, Oscar R. Gonzalez Jan 2005

Performance Analysis And Validation Of A Recoverable Flight Control System In A Simulated Neutron Environment, Hong Zhang, W. Steven Gray, Oscar R. Gonzalez

Electrical & Computer Engineering Faculty Publications

This paper introduces a class of stochastic hybrid models for the analysis of closed-loop control systems implemented with NASA's Recoverable Computer System. Such Recoverable Computer Systems have been proposed to insure reliable control performance in harsh environments. The stochastic hybrid models consist of either a stochastic finite-state automaton or a finite-state machine driven by a Markov input, which in turn drives a switched linear discrete-time dynamical system. Their stability and output tracking performance are analyzed using an extension of the existing theory for Markov jump-linear systems. For illustration, a stochastic hybrid model is used to calculate the tracking error performance …

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A Heuristic With Bounded Guarantee To Compute Diverse Paths Under Shared Protection In Wdm Mesh Networks, Ajay Todimala, Byrav Ramamurthy Jan 2005

A Heuristic With Bounded Guarantee To Compute Diverse Paths Under Shared Protection In Wdm Mesh Networks, Ajay Todimala, Byrav Ramamurthy

School of Computing: Conference and Workshop Papers

Establishing a fault-tolerant connection in a network involves computation of diverse working and protection paths. The Shared Risk Link Group (SRLG) [1] concept is used to model several types of failure conditions such as link, node, fiber conduit, etc. In this work we focus on the problem of computing optimal SRLG/link diverse paths under shared protection. Shared protection technique improves network resource utilization by allowing protection paths of multiple connections to share resources. In this work we propose an iterative heuristic for computing SRLG/link diverse paths. We present a method to calculate a quantitative measure that provides a bounded guarantee …

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An Empirical Study Of Fault Localization For End-User Programmers, Joseph R. Ruthruff, Margaret Burnett, Gregg Rothermel Jan 2005

An Empirical Study Of Fault Localization For End-User Programmers, Joseph R. Ruthruff, Margaret Burnett, Gregg Rothermel

School of Computing: Conference and Workshop Papers

End users develop more software than any other group of programmers, using software authoring devices such as e-mail filtering editors, by-demonstration macro builders, and spreadsheet environments. Despite this, there has been little research on finding ways to help these programmers with the dependability of their software. We have been addressing this problem in several ways, one of which includes supporting end-user debugging activities through fault localization techniques. This paper presents the results of an empirical study conducted in an end-user programming environment to examine the impact of two separate factors in fault localization techniques that affect technique effectiveness. Our results …

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A Controlled Experiment Assessing Test Case Prioritization Techniques Via Mutation Faults, Hyunsook Do, Gregg Rothermel Jan 2005

A Controlled Experiment Assessing Test Case Prioritization Techniques Via Mutation Faults, Hyunsook Do, Gregg Rothermel

School of Computing: Conference and Workshop Papers

Regression testing is an important part of software maintenance, but it can also be very expensive. To reduce this expense, software testers may prioritize their test cases so that those that are more important are run earlier in the regression testing process. Previous work has shown that prioritization can improve a test suite’s rate of fault detection, but the assessment of prioritization techniques has been limited to hand-seeded faults, primarily due to the belief that such faults are more realistic than automatically generated (mutation) faults. A recent empirical study, however, suggests that mutation faults can be representative of real faults. …

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Helping End-Users “Engineer” Dependable Web Applications, Sebastian Elbaum, Kalyan-Ram Chilakamarri, Bhuvana Gopal, Gregg Rothermel Jan 2005

Helping End-Users “Engineer” Dependable Web Applications, Sebastian Elbaum, Kalyan-Ram Chilakamarri, Bhuvana Gopal, Gregg Rothermel

School of Computing: Conference and Workshop Papers

End-user programmers are increasingly relying on web authoring environments to create web applications. Although often consisting primarily of web pages, such applications are increasingly going further, harnessing the content available on the web through “programs” that query other web applications for information to drive other tasks. Unfortunately, errors can be pervasive in web applications, impacting their dependability. This paper reports the results of an exploratory study of end-user web application developers, performed with the aim of exposing prevalent classes of errors. The results suggest that end-users struggle the most with the identification and manipulation of variables when structuring requests to …

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Balancing Exploration And Exploitation: A New Algorithm For Active Machine Learning, Thomas Osugi, Deng Kun, Stephen Scott Jan 2005

Balancing Exploration And Exploitation: A New Algorithm For Active Machine Learning, Thomas Osugi, Deng Kun, Stephen Scott

School of Computing: Conference and Workshop Papers

Active machine learning algorithms are used when large numbers of unlabeled examples are available and getting labels for them is costly (e.g. requiring consulting a human expert). Many conventional active learning algorithms focus on refining the decision boundary, at the expense of exploring new regions that the current hypothesis misclassifies. We propose a new active learning algorithm that balances such exploration with refining of the decision boundary by dynamically adjusting the probability to explore at each step. Our experimental results demonstrate improved performance on data sets that require extensive exploration while remaining competitive on data sets that do not. Our …

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Disseminating Usability Design Knowledge Through Ontology-Based Pattern Languages, Scott Henninger, Padmapriya Ashokkumar Jan 2005

Disseminating Usability Design Knowledge Through Ontology-Based Pattern Languages, Scott Henninger, Padmapriya Ashokkumar

School of Computing: Technical Reports

Usability patterns represent knowledge about known ways to design graphical user interfaces that are usable and meet the needs and expectations of users. There is currently a plethora of usability patterns published in books, private repositories and the World-Wide Web. The dominance of pattern discovery efforts has neglected the emerging need to organize the patterns so they can become a proactive resource for developing interfaces. This paper presents an approach using Semantic Web concepts that turns informal patterns into formal representations capable of supporting systematic design methods. Through this method, loosely coupled pattern collections can be turned into strongly coupled …

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Dgkd: Distributed Group Key Distribution With Authentication Capability, Pratima Adusumilli, Xukai Zou, Byrav Ramamurthy Jan 2005

Dgkd: Distributed Group Key Distribution With Authentication Capability, Pratima Adusumilli, Xukai Zou, Byrav Ramamurthy

School of Computing: Conference and Workshop Papers

Group key management (GKM} is the most important issue in secure group communication (SCC). The existing GKM protocols fall into three typical classes: centralized group key distribution (CGKD), decentralized group key management (DGKM), and distributed/contributory group key agreement (CGKA). Serious problems remains in these protocols, as they require existence of central trusted entities (such as group controller or subgroup controllers), relaying of messages (by subgroup controllers), or strict member synchronization (JOT multiple round stepwise key agreement), thus suffering from the single point of failure and attack, performance bottleneck, or mis-operations in the situation of transmission delay or network failure. In …

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Crtdh: An Efficient Key Agreement Scheme For Secure Group Communications In Wireless Ad Hoc Networks, Ravi K Balachandran, Byrav Ramamurthy, Xukai Zou, N.V. Vinodchandran Jan 2005

Crtdh: An Efficient Key Agreement Scheme For Secure Group Communications In Wireless Ad Hoc Networks, Ravi K Balachandran, Byrav Ramamurthy, Xukai Zou, N.V. Vinodchandran

School of Computing: Conference and Workshop Papers

As a result of the growing popularity of wireless networks, in particular ad hoc networks, security over such networks has become very important. In this paper, we study the problem of secure group communications (SGC) and key management over ad hoc networks. We identify the key features of any SGC protocol for such networks. We also propose an efficient key agreement scheme for SGC. The scheme solves two important problems that exist in most current SGC schemes: requirement of member serialization and existence of a central entity. Besides this, the protocol also has many highly desirable properties such as contributory …

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Same-Destination-Intermediate Grouping Vs. End-To-End Grouping For Waveband Switching In Wdm Mesh Networks, Mengke Li, Wang Yao, Byrav Ramamurthy Jan 2005

Same-Destination-Intermediate Grouping Vs. End-To-End Grouping For Waveband Switching In Wdm Mesh Networks, Mengke Li, Wang Yao, Byrav Ramamurthy

School of Computing: Conference and Workshop Papers

We investigate waveband switching (WBS) with different grouping strategies in wavelength-division multiplexing (WDM) mesh networks. End-to-end waveband switching (ETEWBS) and same-destination-intermediate waveband switching (SD-IT-WBS) are analyzed and compared in terms of blocking probability and cost savings. First, an analytical model for ETEWBS is proposed to determine the network blocking probability in a mesh network. For SD-IT-WBS, a simple waveband switching algorithm is presented. An analytical model to determine the network blocking probability is proposed for SD-IT-WBS based on the algorithm. The analytical results are validated by comparing with simulation results. Both results match well and show that ETE-WBS slightly outperforms …

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A Novel Cost-Efficient On-Line Intermediate Waveband-Switching Scheme In Wdm Mesh Networks, Mengke Li, Wang Yao, Byrav Ramamurthy Jan 2005

A Novel Cost-Efficient On-Line Intermediate Waveband-Switching Scheme In Wdm Mesh Networks, Mengke Li, Wang Yao, Byrav Ramamurthy

School of Computing: Conference and Workshop Papers

Waveband switching (WBS) is an important technique to save switching and transmission cost in wavelength -division multiplexed (WDM) optical networks. A cost-efficient WBS scheme would enable network carriers to increase the network throughput (revenue) while achieving significant cost savings. We identify the critical factors that determine the WBS network throughput and switching cost and propose a novel intermediate waveband switching (IT-WBS) algorithm, called the minimizing-weighted-cost (MWC) algorithm. The MWC algorithm defines a cost for each candidate route of a call. By selecting the route with the smallest weighted cost, MWC balances between minimizing the call blocking probability and minimizing the …

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Towards More Comprehensive Information Retrieval Systems: Entity Extraction Using Xslt, Chris A. Mcmanigal Jan 2005

Towards More Comprehensive Information Retrieval Systems: Entity Extraction Using Xslt, Chris A. Mcmanigal

UNF Graduate Theses and Dissertations

One problem that exists in today's document management arena is the issue of retrieving information from electronic documents such as images, Microsoft Office documents, and e-mail. Specific data entities must be extracted from these documents so that the data can be searched and queried. This study presents a unique approach to extracting these entities: using Extensible Stylesheet Language Transformations (XSLT) to match patterns in text. Because XSLT is processed at run time, new XSLT templates can be created and used without having to recompile and redeploy the application. The specific implementation addressed in this project extracts entities from an image …

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An End-User Development Approach To Building Customizable Web-Based Document Workflow Management Systems, Stacy Hutchings Jan 2005

An End-User Development Approach To Building Customizable Web-Based Document Workflow Management Systems, Stacy Hutchings

UNF Graduate Theses and Dissertations

As organizations seek to control their practices through Business Process Management (BPM - or the process of improving the efficiency and effectiveness of an organization through the automation of tasks), workflow management systems (WFMS) have emerged as fundamental supporting software tools. A WFMS must maintain process state while managing the utilization of people and applications (resources), data (context), and constraints (rules) associated with each of the tasks [Baeyens04]. It must also be configurable so it can be easily adapted to manage specific workflows within any application domain. Finally, the WFMS should be flexible enough to allow for changing business needs. …

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Autonomous Vehicle Technologies For Small Fixed-Wing Uavs, Randal Beard, Derek Kingston, Morgan Quigley, Deryl Snyder, Reed Christiansen, Walt Johnson, Timothy Mclain, Michael A. Goodrich Jan 2005

Autonomous Vehicle Technologies For Small Fixed-Wing Uavs, Randal Beard, Derek Kingston, Morgan Quigley, Deryl Snyder, Reed Christiansen, Walt Johnson, Timothy Mclain, Michael A. Goodrich

Faculty Publications

The objective of this paper is to describe the design and implementation of a small semi-autonomous fixed-wing unmanned air vehicle. In particular we describe the hardware and software architectures used in the design. We also describe a low weight, low cost autopilot developed at Brigham Young University and the algorithms associated with the autopilot. Novel PDA and voice interfaces to the UAV are described. In addition, we overview our approach to real-time path planning, trajectory generation, and trajectory tracking. The paper is augmented with movie files that demonstrate the functionality of the UAV and its control software.

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