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2005

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Articles 901 - 930 of 1206

Full-Text Articles in Computer Sciences

Epics: A Service Learning Program At Butler University, Jonathan P. Sorenson, Panos K. Linos Jan 2005

Epics: A Service Learning Program At Butler University, Jonathan P. Sorenson, Panos K. Linos

Scholarship and Professional Work - LAS

In this paper we present our experiences teaching EPICS (Engineering Projects In Community Service) at Butler University, a small, private university, from within the Department of Computer Science and Software Engineering. The EPICS program began at Purdue University in 1995. The idea behind EPICS is to have undergraduate students earn college credit for working on long-term, multi-semester projects to benefit charity and non-profit organizations. The projects are student-driven, under faculty supervision. There are many good reasons for having an EPICS program in an undergraduate computer science major. It is excellent for leveraging knowledge from other areas of computer science such …


Finding And Maintaining Rigid Components, Audrey Lee, Ileana Streinu, Louis Theran Jan 2005

Finding And Maintaining Rigid Components, Audrey Lee, Ileana Streinu, Louis Theran

Computer Science: Faculty Publications

We give the first complete analysis that the complexity of finding and maintaining rigid components of planar bar-and-joint frameworks and arbitrary d-dimensional body-and-bar frameworks, using a family of algorithms called pebble games, is O(n2). To this end, we intro- duce a new data structure problem called union pair- find, which maintains disjoint edge sets and supports pair-find queries of whether two vertices are spanned by a set. We present solutions that apply to generalizations of the pebble game algorithms, beyond the original rigidity motivation.


Scene Monitoring With A Forest Of Cooperative Sensors, Omar Javed Jan 2005

Scene Monitoring With A Forest Of Cooperative Sensors, Omar Javed

Electronic Theses and Dissertations

In this dissertation, we present vision based scene interpretation methods for monitoring of people and vehicles, in real-time, within a busy environment using a forest of co-operative electro-optical (EO) sensors. We have developed novel video understanding algorithms with learning capability, to detect and categorize people and vehicles, track them with in a camera and hand-off this information across multiple networked cameras for multi-camera tracking. The ability to learn prevents the need for extensive manual intervention, site models and camera calibration, and provides adaptability to changing environmental conditions. For object detection and categorization in the video stream, a two step detection …


Enhancing Message Privacy In Wired Equivalent Privacy., Darshan Purandare Jan 2005

Enhancing Message Privacy In Wired Equivalent Privacy., Darshan Purandare

Electronic Theses and Dissertations

The 802.11 standard defines the Wired Equivalent Privacy (WEP) and encapsulation of data frames. It is intended to provide data privacy to the level of a wired network. WEP suffered threat of attacks from hackers owing to certain security shortcomings in the WEP protocol. Lately, many new protocols like WiFi Protected Access (WPA), WPA2, Robust Secure Network (RSN) and 802.11i have come into being, yet their implementation is fairly limited. Despite its shortcomings one cannot undermine the importance of WEP as it still remains the most widely used system and we chose to address certain security issues and propose some …


Qos In Cognitive Packet Networks: Adaptive Routing, Flow And Congestion Control, Pu Su Jan 2005

Qos In Cognitive Packet Networks: Adaptive Routing, Flow And Congestion Control, Pu Su

Electronic Theses and Dissertations

With the emergence of various applications that have different Quality of Service (QoS) requirements, the capability of a network to support QoS becomes more and more important and necessary. This dissertation explores QoS in Cognitive Packet Networks (CPN) by using adaptive routing, flow and congestion control. We present a detailed description and analysis of our proposed routing algorithms based on single and multiple QoS constraints. An online estimation of packet loss rate over a path is introduced. We implement and evaluate the adaptive routing scheme in an experimental CPN test-bed. Our experiments support our claims that the users can achieve …


Access Games: A Game Theoretic Framework For Fair Bandwidth Sharing In Distributed Systems, Sudipta Rakshit Jan 2005

Access Games: A Game Theoretic Framework For Fair Bandwidth Sharing In Distributed Systems, Sudipta Rakshit

Electronic Theses and Dissertations

In this dissertation, the central objective is to achieve fairness in bandwidth sharing amongst selfish users in a distributed system. Because of the inherent contention-based nature of the distributed medium access and the selfishness of the users, the distributed medium access is modeled as a non-cooperative game; designated as the Access Game. A p-CSMA type medium access scenario is proposed for all the users. Therefore, in the Access Game, each user has two actions to choose from: "transmit" and "wait". The outcome of the Access Game and payoffs to each user depends on the actions taken by all the users. …


Resource Allocation Schemes And Performance Evaluation Models For Wavelength Division Multiplexed Optical Networks, Mounire El Houmaidi Jan 2005

Resource Allocation Schemes And Performance Evaluation Models For Wavelength Division Multiplexed Optical Networks, Mounire El Houmaidi

Electronic Theses and Dissertations

Wavelength division multiplexed (WDM) optical networks are rapidly becoming the technology of choice in network infrastructure and next-generation Internet architectures. WDM networks have the potential to provide unprecedented bandwidth, reduce processing cost, achieve protocol transparency, and enable efficient failure handling. This dissertation addresses the important issues of improving the performance and enhancing the reliability of WDM networks as well as modeling and evaluating the performance of these networks. Optical wavelength conversion is one of the emerging WDM enabling technologies that can significantly improve bandwidth utilization in optical networks. A new approach for the sparse placement of full wavelength converters based …


A Brief History Of Bioperl, Colin Crossman, Arti K. Rai Jan 2005

A Brief History Of Bioperl, Colin Crossman, Arti K. Rai

Faculty Scholarship

Large-scale open-source projects face a litany of pitfalls and difficulties. Problems of contribution quality, credit for contributions, project coordination, funding, and mission-creep are ever-present. Of these, long-term funding and project coordination can interact to form a particularly difficult problem for open-source projects in an academic environment.

BioPerl was chosen as an example of a successful academic open-source project. Several of the roadblocks and hurdles encountered and overcome in the development of BioPerl are examined through the telling of the history of the project. Along the way, key points of open-source law are explained, such as license choice and copyright.

The …


Srt Division Algorithms As Dynamical Systems, Mark Mccann, Nicholas Pippenger Jan 2005

Srt Division Algorithms As Dynamical Systems, Mark Mccann, Nicholas Pippenger

All HMC Faculty Publications and Research

Sweeney--Robertson--Tocher (SRT) division, as it was discovered in the late 1950s, represented an important improvement in the speed of division algorithms for computers at the time. A variant of SRT division is still commonly implemented in computers today. Although some bounds on the performance of the original SRT division method were obtained, a great many questions remained unanswered. In this paper, the original version of SRT division is described as a dynamical system. This enables us to bring modern dynamical systems theory, a relatively new development in mathematics, to bear on an older problem. In doing so, we are able …


Efficient Test Compaction For Pseudo-Random Testing, Sheng Zhang, Sharad C. Seth, Bhargab B. Bhattacharya Jan 2005

Efficient Test Compaction For Pseudo-Random Testing, Sheng Zhang, Sharad C. Seth, Bhargab B. Bhattacharya

School of Computing: Conference and Workshop Papers

Compact set of 3-valued test vectors for random pattern resistant faults are covered in multiple test passes. During a pass, its associated test cube specifies certain bits in the scan chain to be held fixed and others to change pseudo-randomly. We propose an algorithm to find a small number of cubes to cover all the test vectors, thus minimizing total test length. The test-cube finding algorithm repeatedly evaluates small perturbations of the current solution so as to maximize the expected test coverage of the cube. Experimental results show that our algorithm covers the test vectors by test cubes that are …


Face Recognition Using Landmark-Based Bidimensional Regression, Jiazheng Shi, Ashok Samal, David Marx Jan 2005

Face Recognition Using Landmark-Based Bidimensional Regression, Jiazheng Shi, Ashok Samal, David Marx

School of Computing: Conference and Workshop Papers

This paper studies how biologically meaningful landmarks extracted from face images can be exploited for face recognition using the bidimensional regression. Incorporating the correlation statistics of landmarks, this paper also proposes a new approach called eigenvalue weighted bidimensional regression. Complex principal component analysis is used for computing eigenvalues and removing correlation among landmarks. We evaluate our approach using two standard face databases: the Purdue AR and the NIST FERET. Experimental results show that the bidimensional regression is an efficient method to exploit geometry information of face images.


Ground Water Monitoring Using Smart Sensors, Srikanth Anumalla, Byrav Ramamurthy, David Gosselin Jan 2005

Ground Water Monitoring Using Smart Sensors, Srikanth Anumalla, Byrav Ramamurthy, David Gosselin

School of Computing: Conference and Workshop Papers

Groundwater resources are the principal source of drinking water for about 50 percent of the United States population. Groundwater resources in Nebraska are under increasing stress as there is a rapid growth in their usage. Water managers need more timely and accurate data to assess ground-water conditions to manage adverse situations such as drought and loss of pumpage in agriculture and domestic water supply. Currently groundwater researchers use stand-alone data logging equipment which is labor intensive and the method is not easily scalable if the number of logging locations increases. Commercially available real-time data monitoring solutions are either prohibitively costly …


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 …


Least-Cost Disjoint Paths With Dependent Cost Structure In Wavelength Continuous Optical Wdm Networks, Ajay Todimala, Byrav Ramamurthy Jan 2005

Least-Cost Disjoint Paths With Dependent Cost Structure In Wavelength Continuous Optical Wdm Networks, Ajay Todimala, Byrav Ramamurthy

School of Computing: Conference and Workshop Papers

One of the important issues in establishing a fault tolerant connection in a wavelength division multiplexing optical network is computing a pair of disjoint working and protection paths and a free wavelength along the paths. While most of the earlier research focused only on computing disjoint paths, in this work we consider computing both disjoint paths and a free wavelength along the paths.

The concept of dependent cost structure (DCS) of protection paths to enhance their resource sharing ability was proposed in our earlier work. In this work we extend the concept of DCS of protection paths to wavelength continuous …


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 …


Assessing The Cost-Benefits Of Using Type Inference Algorithms To Improve The Representation Of Exceptional Control Flow In Java, Alex Kinneer, Gregg Rothermel Jan 2005

Assessing The Cost-Benefits Of Using Type Inference Algorithms To Improve The Representation Of Exceptional Control Flow In Java, Alex Kinneer, Gregg Rothermel

School of Computing: Technical Reports

Accurate representations of program control flow are important to the soundness and efficiency of program analysis and testing techniques. The Java programming language has introduced structured exception handling features that complicate the task of constructing safe and precise representations of the possible control flow in Java programs. Prior work has considered applying various type inference algorithms to exceptions, but has not yet investigated whether the use of higher cost algorithms is necessarily justified. It is important to understand and assess the tradeoffs associated with the use of more powerful yet costly algorithms, thus we conducted an empirical study to evaluate …


Computing Rigid Components Of Pseudo-Triangulation Mechanisms In Linear Time, Jack Snoeyink, Ileana Streinu Jan 2005

Computing Rigid Components Of Pseudo-Triangulation Mechanisms In Linear Time, Jack Snoeyink, Ileana Streinu

Computer Science: Faculty Publications

We investigate the problem of detecting rigid components (maximal Laman subgraphs) in a pseudotriangulation mechanism and in arbitrary pointed planar frameworks.F or general Laman graphs with some missing edges, it is known that rigid components can be computed in O(n2) time.Here we make substantial use of the special geometry of pointed pseudo-triangulation mechanisms to achieve linear time. The main application is a more robust implementation and a substantial reduction in numerical computations for the solution to the Carpenter's Rule problem given by the second author.


Pseudo-Triangulations, Rigidity And Motion Planning, Ileana Streinu Jan 2005

Pseudo-Triangulations, Rigidity And Motion Planning, Ileana Streinu

Computer Science: Faculty Publications

This paper proposes a combinatorial approach to planning non-colliding trajectories for a polygonal bar-and-joint framework with n vertices. It is based on a new class of simple motions induced by expansive one-degree-of-freedom mechanisms, which guarantee noncollisions by moving all points away from each other. Their combinatorial structure is captured by pointed pseudo-triangulations, a class of embedded planar graphs for which we give several equivalent characterizations and exhibit rich rigidity theoretic properties. The main application is an efficient algorithm for the Carpenter's Rule Problem: convexify a simple bar-and-joint planar polygonal linkage using only non-self-intersecting planar motions. A step of the algorithm …


Methods For Approximate Reasoning, Perry Groot, Pascal Hitzler, Ian Horrocks, Boris Motik, Jeff Z. Pan, Heiner Stuckenschmidt, Daniele Turi, Holger Wache Jan 2005

Methods For Approximate Reasoning, Perry Groot, Pascal Hitzler, Ian Horrocks, Boris Motik, Jeff Z. Pan, Heiner Stuckenschmidt, Daniele Turi, Holger Wache

Computer Science and Engineering Faculty Publications

This deliverable shows examples about approximating symbolic inference engines in a Semantic Web environment. Approaches of language weakening, knowledge compilation, and approximated deduction are presented. The last one is evaluated in practical applications with mixed results.


Visualizing Very Large-Scale Vascular Structures Interactively, Thomas Wischgoll, Joerg Meyer, Benjamin Kaimovitz, Yoram Lanir, Ghassan S. Kassab Jan 2005

Visualizing Very Large-Scale Vascular Structures Interactively, Thomas Wischgoll, Joerg Meyer, Benjamin Kaimovitz, Yoram Lanir, Ghassan S. Kassab

Computer Science and Engineering Faculty Publications

No abstract provided.


An Explorational Exhibit Of A Pig's Heart, Thomas Wischgoll, Joerg Meyer Jan 2005

An Explorational Exhibit Of A Pig's Heart, Thomas Wischgoll, Joerg Meyer

Computer Science and Engineering Faculty Publications

No abstract provided.


The "Best K" For Entropy-Based Categorical Data Clustering, Keke Chen, Ling Liu Jan 2005

The "Best K" For Entropy-Based Categorical Data Clustering, Keke Chen, Ling Liu

Kno.e.sis Publications

With the growing demand on cluster analysis for categorical data, a handful of categorical clustering algorithms have been developed. Surprisingly, to our knowledge, none has satisfactorily addressed the important problem for categorical clustering – how can we determine the best K number of clusters for a categorical dataset? Since categorical data does not have the inherent distance function as the similarity measure, traditional cluster validation techniques based on the geometry shape and density distribution cannot be applied to answer this question. In this paper, we investigate the entropy property of the categorical data and propose a BkPlot method for determining …


Predicting Software Size And Development Effort: Models Based On Stepwise Refinement, David P. Voorhees Jan 2005

Predicting Software Size And Development Effort: Models Based On Stepwise Refinement, David P. Voorhees

CCAC Theses and Dissertations

This study designed a Software Size Model and an Effort Prediction Model, then performed an empirical analysis of these two models. Each model design began with identifying its objectives, which led to describing the concept to be measured and the meta-model. The numerical assignment rules were then developed, providing a basis for size measurement and effort prediction across software engineering projects. The Software Size Model was designed to test the hypothesis that a software size measure represents the amount of knowledge acquired and stored in software artifacts, and the amount of time it took to acquire and store this knowledge. …


Robust Temporal Constraint Networks, Hoong Chuin Lau, Thomas Ou, Melvyn Sim Jan 2005

Robust Temporal Constraint Networks, Hoong Chuin Lau, Thomas Ou, Melvyn Sim

Research Collection School Of Computing and Information Systems

In this paper, we propose the Robust Temporal Constraint Network (RTCN) model for simple temporal constraint networks where activity durations are bounded by random variables. The problem is to determine whether such temporal network can be executed with failure probability less than a given 0 ≤ E ≤ 1 for each possible instantiation of the random variables, and if so. how one might find a feasible schedule with each given instantiation. The advantage of our model is that one can vary the value of ∊ to control the level of conservativeness of the solution. We present a computationally tractable and …


Revising And Unifying The Use Case Textual And Graphical Worlds, Pierre Metz Jan 2005

Revising And Unifying The Use Case Textual And Graphical Worlds, Pierre Metz

Theses

This thesis traces the evolution of use cases and use case relationships from the initial suggestion by Jacobson et al. in OOSE until today. This tracing reveals that there are two distinct streams of development, as referred in this thesis to as the “textual world” and the “graphical world”: the textual world being literature concentrating on textual use case properties, i.e. use case writing techniques and use case templates. The second stream that has been developed in parallel with the use case template progression is UML, i.e. Unified Modeling Language, which defines the standard for the use case diagram notation …


Numerical Modelling Of Sediments In Cork Harbour, Jérémy Pingon Jan 2005

Numerical Modelling Of Sediments In Cork Harbour, Jérémy Pingon

Theses

In recent years there have been considerable developments in the new and emerging field of hydroinformatics. This relatively new discipline is concerned with the application of computer and networking technology for the planning, management and protection of water bodies.

Environmental issues in estuaries require accurate and detailed knowledge of cohesive sediment transport processes to assess different issues including water quality, pollutant dispersion, and dredging and maintenance of navigation channels.

This thesis presents a review of the main sediment properties and processes required for modelling the behaviour and transport of sediments. It also introduces a new approach to sediment properties using …


Building A Declarative Workflow Engine, Patrick Rushe Jan 2005

Building A Declarative Workflow Engine, Patrick Rushe

Theses

In the last two decades, technology has become available that not only allows certain activities of a business process to be automated, but also allows a business process itself to be automatically managed. A Workflow Management System assigns the work, passes it on, and tracks its progress. This technology is called Workflow. Workflow is the automation and formal management of a business process.

Many commercial and open-source Workflow Management Systems are available. However, the cost and technical difficulty in implementing either can be excessively high. The primary contribution of this work is to prove that building a workflow engine is …


Predictive Congestion Control Mac Protocol For Wireless Sensor Networks, Maciej Jan Zawodniok, Jagannathan Sarangapani Jan 2005

Predictive Congestion Control Mac Protocol For Wireless Sensor Networks, Maciej Jan Zawodniok, Jagannathan Sarangapani

Electrical and Computer Engineering Faculty Research & Creative Works

Available congestion control schemes, for example transport control protocol (TCP), when applied to wireless networks results in a large number of packet drops, unfairness with a significant amount of wasted energy due to retransmissions. To fully utilize the hop by hop feedback information, a suite of novel, decentralized, predictive congestion control schemes are proposed for wireless sensor networks in concert with distributed power control (DPC). Besides providing energy efficient solution, embedded channel estimator in DPC predicts the channel quality. By using the channel quality and node queue utilizations, the onset of network congestion is predicted and congestion control is initiated. …


A Multi-Hypothesis Approach For Salient Object Tracking In Visual Surveillance, Filiz Bunyak, Ilker Ersoy, S. R. Subramanya Jan 2005

A Multi-Hypothesis Approach For Salient Object Tracking In Visual Surveillance, Filiz Bunyak, Ilker Ersoy, S. R. Subramanya

Electrical and Computer Engineering Faculty Research & Creative Works

In this paper, a multiple object tracking method for visual surveillance applications is presented. Moving objects are detected by adaptive background subtraction and tracked by using a multi-hypothesis testing approach. Object matching between frames is done based on proximity and appearance similarity. a new confidence measure is assigned to each possible match. This information is arranged into a graph structure where vertices represent blobs in consecutive frames and edges represent match confidence values. This graph is later used to prune and refine trajectories to obtain the salient object trajectories. Occlusions are handled through position prediction using Kalman filter and robust …


Block Phase Correlation-Based Automatic Drift Compensation For Atomic Force Microscopes, Qinmin Yang, Eric W. Bohannan, Jagannathan Sarangapani Jan 2005

Block Phase Correlation-Based Automatic Drift Compensation For Atomic Force Microscopes, Qinmin Yang, Eric W. Bohannan, Jagannathan Sarangapani

Electrical and Computer Engineering Faculty Research & Creative Works

Automatic nanomanipulation and nanofabrication with an Atomic Force Microscope (AFM) is a precursor for nanomanufacturing. In ambient conditions without stringent environmental controls, nanomanipulation tasks require extensive human intervention to compensate for the many spatial uncertainties of the AFM. Among these uncertainties, thermal drift is especially hard to solve because it tends to increase with time and cannot be compensated simultaneously by feedback. In this paper, an automatic compensation scheme is introduced to measure and estimate drift. This information can be subsequently utilized to compensate for the thermal drift so that a real-time controller for nanomanipulation can be designed as if …