Open Access. Powered by Scholars. Published by Universities.®

Computer Sciences Commons

Open Access. Powered by Scholars. Published by Universities.®

Old Dominion University

Discipline
Keyword
Publication Year
Publication
Publication Type
File Type

Articles 1381 - 1410 of 1996

Full-Text Articles in Computer Sciences

A Nonrigid Registration Method For Correcting Brain Deformation Induced By Tumor Resection, Yixun Liu, Chengjun Yao, Fotis Drakopoulos, Jinsong Wu, Liangfu Zhou, Nikos Chrisochoides Jan 2014

A Nonrigid Registration Method For Correcting Brain Deformation Induced By Tumor Resection, Yixun Liu, Chengjun Yao, Fotis Drakopoulos, Jinsong Wu, Liangfu Zhou, Nikos Chrisochoides

Computer Science Faculty Publications

Purpose: This paper presents a nonrigid registration method to align preoperative MRI with intraoperative MRI to compensate for brain deformation during tumor resection. This method extends traditional point-based nonrigid registration in two aspects: (1) allow the input data to be incomplete and (2) simulate the underlying deformation with a heterogeneous biomechanical model.

Methods: The method formulates the registration as a three-variable (point correspondence, deformation field, and resection region) functional minimization problem, in which point correspondence is represented by a fuzzy assign matrix; Deformation field is represented by a piecewise linear function regularized by the strain energy of a heterogeneous biomechanical …


Moved But Not Gone: An Evaluation Of Real-Time Methods For Discovering Replacement Web Pages, Martin Klein, Michael L. Nelson Jan 2014

Moved But Not Gone: An Evaluation Of Real-Time Methods For Discovering Replacement Web Pages, Martin Klein, Michael L. Nelson

Computer Science Faculty Publications

Inaccessible Web pages and 404 “Page Not Found” responses are a common Web phenomenon and a detriment to the user’s browsing experience. The rediscovery of missing Web pages is, therefore, a relevant research topic in the digital preservation as well as in the Information Retrieval realm. In this article, we bring these two areas together by analyzing four content- and link-based methods to rediscover missing Web pages. We investigate the retrieval performance of the methods individually as well as their combinations and give an insight into how effective these methods are over time. As the main result of this work, …


Enhancing Understanding Of Discrete Event Simulation Models Through Analysis, Kara Ann Olson Jan 2014

Enhancing Understanding Of Discrete Event Simulation Models Through Analysis, Kara Ann Olson

Computer Science Theses & Dissertations

Simulation is used increasingly throughout research, development, and planning for many purposes. While model output is often the primary interest, insights gained through the simulation process can also be valuable. Insights can come from building and validating the model as well as analyzing its behaviors and output; however, much that could be informative may not be easily discernible through these existing traditional approaches, particularly as models continue to increase in complexity.

This research extends current work in model analysis and program understanding to assist modelers in obtaining more insight into their models and the systems they represent. A primary technique …


Telling Stories With Web Archives, Michele C. Weigle Nov 2013

Telling Stories With Web Archives, Michele C. Weigle

Computer Science Presentations

PDF of a powerpoint presentation from the Southeast Women in Computing Conference in Lake Guntersville State Park, Alabama, November 16, 2013. Also available on Slideshare.


Control System Of An Atomic Layer Deposition (Ald) Machine, Nitin Vishnu Hegde Oct 2013

Control System Of An Atomic Layer Deposition (Ald) Machine, Nitin Vishnu Hegde

Electrical & Computer Engineering Theses & Dissertations

Atomic Layer Deposition is one of the most efficient deposition processes for obtaining ultrathin films. The deposition by this process happens one atomic layer at a time. ALD is known for its precision and ability to develop quality films with great thickness control. ALD machines simultaneously control DC and AC currents, low pressure operations, temperature control and heating (up to 500'C), precision flow control, precision timing intervals for deposition (milli-second intervals) and constantly monitor temperature. Such a high control comes at a high price. Furthermore, at the university level, the capacity to modify or enhance a machine is critical but …


Use Of Immersive Visualization For The Control Of Dental Anxiety During Dental Hygiene Treatment, Carmelo Padrino-Barrios Oct 2013

Use Of Immersive Visualization For The Control Of Dental Anxiety During Dental Hygiene Treatment, Carmelo Padrino-Barrios

Dental Hygiene Theses & Dissertations

Purpose: The purpose of this study was to determine the effectiveness of immersive visualization (IV) therapy, a technique that provides visual and stereoscopic display through the use of eyewear, in anxious patients during an oral prophylaxis. Methods: A convenience sample of thirty adults was enrolled. A split mouth design was utilized. Subjects were randomly divided into two groups: group A (use of IV for the right side of the mouth), and group B (use of IV for the left side of the mouth). Subjects received a full mouth oral prophylaxis (removal of supra and subgingival calculus and selective polishing), always …


Parallel Implementations Of The Frank-Wolfe Algorithms For The Traffic Assignment Problem, Shawn Eugene Allen Oct 2013

Parallel Implementations Of The Frank-Wolfe Algorithms For The Traffic Assignment Problem, Shawn Eugene Allen

Computational Modeling & Simulation Engineering Theses & Dissertations

Transportation planners seek to understand how to best invest limited resources for future transportation network development. The traffic assignment problem is one algorithm of great importance to planners because it provides insight into how traffic will flow within the network. The Frank-Wolfe algorithm is a traditional solution method for this optimization problem, but it has been characterized by its slow rate of convergence and poor computational performance. This thesis examines and implements several modern advancements in this algorithm which are designed to improve the rate of convergence.

In addition to algorithm changes, another method to improve the performance of an …


Using Real Property Layouts To Study The Foreclosure Contagion Effect In Real Estate With Agent-Based Modeling And Simulation, Daniele Vernon-Bido Oct 2013

Using Real Property Layouts To Study The Foreclosure Contagion Effect In Real Estate With Agent-Based Modeling And Simulation, Daniele Vernon-Bido

Computational Modeling & Simulation Engineering Theses & Dissertations

Foreclosures in the United States increased sharply from 2007 to 2009. These foreclosures had a spillover effect on neighboring property values causing additional foreclosures. This is known as the foreclosure contagion effect.

Recent studies have quantified the discount attributed to foreclosure contagion using equation-based techniques. However, the discount varied between studies and markets. Further studies using agent-based modeling and simulation have demonstrated the relationship between the discounts, the time a foreclosure remains on the market, the prevailing interest rates and the average property values.

This study uses agent-based modeling and simulation (ABMS) to explore the differences that varying neighborhood densities …


Linear Programming Algorithm With Mixed Real-Integer Variables In Matlab Environments, Gelareh Bakhtyar Jul 2013

Linear Programming Algorithm With Mixed Real-Integer Variables In Matlab Environments, Gelareh Bakhtyar

Civil & Environmental Engineering Theses & Dissertations

Efficient numerical procedures for solving general Linear Programming (LP) problems with mixed real-integer variables are developed in this work. The proposed algorithms employ the revised dual simplex with Branch and Bound (B&B) algorithms, with special procedures for limited search of subsequent branches. Computational time can be significantly reduced by incorporating the updated inverse formulas into the developed procedures. Both generic LP problems and deterministic pavement maintenance and rehabilitation (M&R) problems are used in this study to vaiidate the developed procedures. Medium to large-scale examples ( 11 pavement M&R) presented in this work have demonstrated that the developed numerical procedures consistently …


Http Mailbox - Asynchronous Restful Communication, Sawood Alam Jul 2013

Http Mailbox - Asynchronous Restful Communication, Sawood Alam

Computer Science Theses & Dissertations

Traditionally, general web services used only the GET and POST methods of HTTP while several other HTTP methods like PUT, PATCH, and DELETE were rarely utilized. Additionally, the Web was mainly navigated by humans using web browsers and clicking on hyperlinks or submitting HTML forms. Clicking on a link is always a GET request while HTML forms only allow GET and POST methods. Recently, several web frameworks/libraries have started supporting RESTful web services through APIs. To support HTTP methods other than GET and POST in browsers, these frameworks have used hidden HTML form fields as a workaround to convey the …


A Multi-Configuration Display Methodology Incorporating Reflection For Real-Time Haptic-Interactive Virtual Environments, Mohammad F. Obeid Jul 2013

A Multi-Configuration Display Methodology Incorporating Reflection For Real-Time Haptic-Interactive Virtual Environments, Mohammad F. Obeid

Computational Modeling & Simulation Engineering Theses & Dissertations

There is a natural need for real-time min-or reflection in many interactive virtual reality applications to achieve visuo-haptic collocation through optical reflection. Its use, however, calls for adjustments to the original model since a mirror reverses image characteristics. This thesis introduces a design and implementation of a generic configuration component for virtual environments that adjusts image characteristics and haptic interfaces to accommodate various display setups while preserving the correct orientation and properties of the original models in the graphical scene. Four different but related approaches were developed for image connection and are compared and contrasted against primary criteria. The haptic …


Multi-Objective Preliminary Design Optimization Of Planing Craft Using Differential Evolution And Artificial Networks, Robert Eugene Weidman Jul 2013

Multi-Objective Preliminary Design Optimization Of Planing Craft Using Differential Evolution And Artificial Networks, Robert Eugene Weidman

Mechanical & Aerospace Engineering Theses & Dissertations

The differential evolution (DE) algorithm is an evolutionary algorithm that has been utilized as a metaheuristic optimizer in the last few years. A recently developed multi-objective version of DE is utilized in this research in order to optimize the preliminary design of planing craft. The craft performance is evaluated using the planing hull preliminary design software PHAST. The optimization problem objectives are the craft acquisition cost and the overall measure of effectiveness; the latter comprises various performance aspects: ride quality, transportability, payload, and mobility. Static stability and operating constraints are also considered. Each of the aforementioned four measures of effectiveness …


Optimization Of Solar Cell Arrays Using The Fibonacci Search Algorithm, Felicia Tyyan Farrow Jul 2013

Optimization Of Solar Cell Arrays Using The Fibonacci Search Algorithm, Felicia Tyyan Farrow

Electrical & Computer Engineering Theses & Dissertations

In our energy hungry world, there is a growing demand to develop creative mechanisms to extract, conserve, and use energy from different resources. The use of solar cells to extract and convert solar energy into electrical energy is a growing and popular field of study because solar energy is clean, free, and renewable. One limitation for photovoltaic (PU) or solar technology is its loss in efficiency and availability as a result of shading or partial shading. Shading or partial shading decreases the total capable output power that the PV system can produce because the array is receiving irradiation from the …


Protein Loop Length Estimation From Medium Resolution Cryoem Images, Andrew R. Mcknight Jul 2013

Protein Loop Length Estimation From Medium Resolution Cryoem Images, Andrew R. Mcknight

Computer Science Theses & Dissertations

In the post-genomic era, proteomics research presents a new frontier in life science. Proteins play roles in virtually every biological process, and understanding their atomic structures is the key to unraveling how they carry out their work. Compared to the over half million protein sequences in UniProt, only around 25,000 unique sequences have been atomically modeled and deposited to PDB (Protein Databank). Cryoelectron Microscopy (cryoEM) is an important biophysical technique that produces 3D subnanometer resolution images of molecules not amenable to past approaches like x-ray crystallography or nuclear magnetic resonance. De novo modeling is becoming a promising approach to derive …


Section Abstracts: Computer Science May 2013

Section Abstracts: Computer Science

Virginia Journal of Science

Abstracts of the Computer Science Section for the 91st Annual Virginia Journal of Science Meeting, May 2013


Computational Dynamics For The Flexible Multi-Body System, Yu Liu Apr 2013

Computational Dynamics For The Flexible Multi-Body System, Yu Liu

Mechanical & Aerospace Engineering Theses & Dissertations

Research in computational dynamics has tremendously developed in the recent years because of the demand for analysis and simulation of various multi-body systems in the growing bio-medical, mechanical and aerospace industries. These multi-body systems are made of individual bodies that are interconnected via mechanical joints. Mathematically, these joints that connect the bodies can be described as constraint equations imposed upon the motions of the involved free bodies. This process will result in an equation of motion expressed in the form of a differential-algebraic equation (DAE). This is one of the main difficulties when dealing with the multi-body system because these …


Impact Of Primary User Activity On The Performance Of Energy-Based Spectrum Sensing In Cognitive Radio Systems, Sara L. Macdonald Apr 2013

Impact Of Primary User Activity On The Performance Of Energy-Based Spectrum Sensing In Cognitive Radio Systems, Sara L. Macdonald

Electrical & Computer Engineering Theses & Dissertations

Increasing numbers of wireless devices and mobile data requirements have led to a spectrum shortage. However spectrum utilization percentages are often low due to the current static spectrum allocation process where primary users (PUs) are given exclusive use to spectrum. Several mechanisms to increase spectrum utilization have been proposed including opportunistic spectrum access (OSA). Cognitive Radio (CR) is an emerging concept in wireless communication systems that aims to enable OSA in licensed frequencies by secondary users (SUs). CR systems are expected to sense the spectrum in order to determine if the PU is transmitting. Therefore OSA performance relies on the …


Study Of Spatiotemporal Signatures Between Objects To Improve Video Segmentation In Complex Environments, Adam Robert Reckley Apr 2013

Study Of Spatiotemporal Signatures Between Objects To Improve Video Segmentation In Complex Environments, Adam Robert Reckley

Electrical & Computer Engineering Theses & Dissertations

Background subtraction is often considered to be a required stage of any video surveillance system being used to detect objects in a single frame and/or track objects across multiple frames in a video sequence. Most current state-of-the-art techniques for object detection and tracking utilize some form of background subtraction that involves developing a model of the background at a pixel, region or frame level and designating any elements that deviate from the background model as foreground. Most existing approaches are capable of segmenting a number of distinct components, but are unable to distinguish between the desired object of interest and …


The Use Of Visual-Based Simulated Environments In Teacher Preparation, Sharon Judge, Jonna Bobzien, Ann Maydosz, Sabra Gear, Petros Katsioloudis Apr 2013

The Use Of Visual-Based Simulated Environments In Teacher Preparation, Sharon Judge, Jonna Bobzien, Ann Maydosz, Sabra Gear, Petros Katsioloudis

Communication Disorders & Special Education Faculty Publications

While virtual technology for training in the simulation field has a long history in medicine, aviation, and the military, the application of similar emerging and innovative technologies in teacher preparation and education has been limited. TLE TeachLive™ (Teaching Learning Environment, Teaching in a Virtual Environment) [TLE] is an inventive mixed-reality environment (the blending of real and synthetic content) where prospective teachers can interact with a group of virtual students. The purpose of the virtual teaching environment of TLE is to strengthen teacher recruitment, preparation, and retention in education by allowing teachers to improve their skills with virtual students, providing a …


Measuring The Value Of Conceptual Modeling A Return On Investment (Roi) Analysis, Jeffrey Alan Brelsford Apr 2013

Measuring The Value Of Conceptual Modeling A Return On Investment (Roi) Analysis, Jeffrey Alan Brelsford

Computational Modeling & Simulation Engineering Theses & Dissertations

This thesis presents a method for calculating the return on investment (ROI) of conceptual modeling. Conceptual modeling as it relates to Modeling and Simulation (M&S) studies is a process that abstracts a model of a real or proposed system to be subsequently used for developing computer models. The conceptual modeling process is a critical constituent in an M&S project because it produces the central reference for building the computer model. Computer models require formal logic to carry out procedures, and consistent arguments in formal logic are crucial for the model to be useful. Not only does formal logic provide the …


Tdma Slot Reservation In Cluster-Based Vanets, Mohammad Salem Almalag Apr 2013

Tdma Slot Reservation In Cluster-Based Vanets, Mohammad Salem Almalag

Computer Science Theses & Dissertations

Vehicular Ad Hoc Networks (VANETs) are a form of Mobile Ad Hoc Networks (MANETs) in which vehicles on the road form the nodes of the network. VANETs provide several services to enhance the safety and comfort of drivers and passengers. These services can be obtained by the wireless exchange of information among the vehicles driving on the road. In particular, the transmission of two different types of messages, safety/update and non-safety messages.

The transmission of safety/update message aims to inform the nearby vehicles about the sender's current status and/or a detected dangerous situation. This type of transmission is designed to …


Special Issue On Medical Simulation, Michel Audette, Hanif M. Ladak Jan 2013

Special Issue On Medical Simulation, Michel Audette, Hanif M. Ladak

Computational Modeling & Simulation Engineering Faculty Publications

We would like to welcome you to this Special Issue on Medical Simulation, the first of its kind not only for SIMULATION: Transactions of The Society for Modeling and Simulation International, but for any technical journal. Our respective backgrounds are an indication of the technical and clinical breadth of medical simulation, as we approach the subject as primarily medical image analysis and biomechanics experts respectively, each with a variety of clinical interests spanning virtual reality (VR)–based neuro-, orthopedic and ear-nose-and-throat surgery. Moreover, we believe that the breadth of the papers that comprise this issue reflects an even broader perspective. After …


Security Risks And Protection In Online Learning: A Survey, Yong Chen, Wu He Jan 2013

Security Risks And Protection In Online Learning: A Survey, Yong Chen, Wu He

Distance Learning Faculty & Staff Publications

This paper describes a survey of online learning which attempts to determine online learning providers' awareness of potential security risks and the protection measures that will diminish them. The authors use a combination of two methods: blog mining and a traditional literature search. The findings indicate that, while scholars have identified diverse security risks and have proposed solutions to mitigate the security threats in online learning, bloggers have not discussed security in online learning with great frequency. The differences shown in the survey results generated by the two different methods confirm that online learning providers and practitioners have not considered …


Using Architecture Models To Design Adaptive Socio-Technical Systems, Holly A. H. Handley Jan 2013

Using Architecture Models To Design Adaptive Socio-Technical Systems, Holly A. H. Handley

Engineering Management & Systems Engineering Faculty Publications

An architecture framework is used to capture the overall design and structure of a complex system. The Human Viewpoint was developed to augment existing architectural frameworks with additional information relevant to the human component in the system. The Human View models collect and organize social parameters in order to understand the way that humans interact with other elements of the system; the Human View models define the socio-technological boundaries of the system. Analyses performed with the architectural data provide information regarding the congruence, or fit of the human and the system. For example, different key thread analyses identify problematic paths …


Unmanned Autonomous Object Retrieval: Old Dominion University 2013 International Aerial Robotics Competition Entry, Johnathan Bailey, Austin Boyd, Chung-Hao Chen, Stephen Dailey, Lisa Henderson, Jeremy Stuart, Christina Williams Jan 2013

Unmanned Autonomous Object Retrieval: Old Dominion University 2013 International Aerial Robotics Competition Entry, Johnathan Bailey, Austin Boyd, Chung-Hao Chen, Stephen Dailey, Lisa Henderson, Jeremy Stuart, Christina Williams

Electrical & Computer Engineering Faculty Publications

This paper describes the design implementation of a Quadrotor Unmanned Aerial Vehicle (UAV) with the capability of exploring indoor locations without the assistance of external aids. For relative position, the use of a laser range sensor, an optical flow sensor, and sonar sensor combined allows for the vehicle to generate mapping information. With relative position in mind, the vehicle uses vision algorithms to recognize immediate obstacles, sign, and entry ways to allow for quick movement responses and object recognition. A proportional-integral-differentiator controller allows for flight stability and mitigation in the tight confines of the indoor spaces. A mapping algorithm allows …


The Root Cause Of Failure In Complex It Projects: Complexity Itself, Kaitlynn M. Whitney, Charles B. Daniels Jan 2013

The Root Cause Of Failure In Complex It Projects: Complexity Itself, Kaitlynn M. Whitney, Charles B. Daniels

Engineering Management & Systems Engineering Faculty Publications

Increased demand for better technology and perpetual global expansion continue to provide developers with many project opportunities for success, as well as failure. While no industry is immune from project failure, the Information Technology (IT) industry is shown to be more susceptible to risk and failure than those of other industries. Agile project management, which facilitates adaptation to changing circumstances and alleviates rigid formal controls, has become more popular in the software development industry though is not entirely compatible with traditional project management approaches.In this paper we will examine the primary causes of IT project management failure stated in modern …


Lattice Boltzmann Simulations Of Thermal Convective Flows In Two Dimensions, Jia Wang, Donghai Wang, Pierre Lallemand, Li-Shi Luo Jan 2013

Lattice Boltzmann Simulations Of Thermal Convective Flows In Two Dimensions, Jia Wang, Donghai Wang, Pierre Lallemand, Li-Shi Luo

Mathematics & Statistics Faculty Publications

In this paper we study the lattice Boltzmann equation (LBE) with multiple-relaxation-time (MRT) collision model for incompressible thermo-hydrodynamics with the Boussinesq approximation. We use the MRT thermal LBE (TLBE) to simulate the following two flows in two dimensions: the square cavity with differentially heated vertical walls and the Rayleigh-Benard convection in a rectangle heated from below. For the square cavity, the flow parameters in this study are the Rayleigh number Ra = 103-106, and the Prandtl number Pr = 0.71; and for the Rayleigh-Benard convection in a rectangle, Ra = 2 . 103, 10 …


Design And Practical Application Of An Innovative, Pneumatically Latched Valve, Cheng Y. Lin, Jennifer G. Michaeli, Nathan J. Luetke Jan 2013

Design And Practical Application Of An Innovative, Pneumatically Latched Valve, Cheng Y. Lin, Jennifer G. Michaeli, Nathan J. Luetke

Engineering Technology Faculty Publications

This article explains the design and fabrication of an innovative five-port, two-position (5/2), pneumatically latched valve. The initial application to repeatedly and automatically lift a mechanical cover or gate was presented as part of an undergraduate student project in the Mechanical Engineering Technology Program's Automation and Controls course in the Department of Engineering Technology at Old Dominion University. Valve operation, including self-latching, utilizes mechanical means only. The valve does not require any electrical power, electronic sensors, or controller, which makes it an energy-saving device. For light-duty operation, a bellows foot-air pump is used for air supply. A single activation of …


Orientation Invariant Ecg-Based Stethoscope Tracking For Heart Auscultation Training On Augmented Standardized Patients, Nahom Kidane, Salim Chemlal, Jiang Li, Frederic D. Mckenzie, Tom Hubbard Jan 2013

Orientation Invariant Ecg-Based Stethoscope Tracking For Heart Auscultation Training On Augmented Standardized Patients, Nahom Kidane, Salim Chemlal, Jiang Li, Frederic D. Mckenzie, Tom Hubbard

Computational Modeling & Simulation Engineering Faculty Publications

Auscultation, the act of listening to the heart and lung sounds, can reveal substantial information about patients’ health and other cardiac-related problems; therefore, competent training can be a key for accurate and reliable diagnosis. Standardized patients (SPs), who are healthy individuals trained to portray real patients, have been extensively used for such training and other medical teaching techniques; however, the range of symptoms and conditions they can simulate remains limited since they are only patient actors. In this work, we describe a novel tracking method for placing virtual symptoms in correct auscultation areas based on recorded ECG signals with various …


Integration Of Multispectral Face Recognition And Multi-Ptz Camera Automated Surveillance For Security Applications, Chung-Hao Chen, Yi Yao, Hong Chang, Andreas Koschan, Mongi Abidi Jan 2013

Integration Of Multispectral Face Recognition And Multi-Ptz Camera Automated Surveillance For Security Applications, Chung-Hao Chen, Yi Yao, Hong Chang, Andreas Koschan, Mongi Abidi

Electrical & Computer Engineering Faculty Publications

Due to increasing security concerns, a complete security system should consist of two major components, a computer-based face-recognition system and a real-time automated video surveillance system. A computer-based face-recognition system can be used in gate access control for identity authentication. In recent studies, multispectral imaging and fusion of multispectral narrow-band images in the visible spectrum have been employed and proven to enhance the recognition performance over conventional broad-band images, especially when the illumination changes. Thus, we present an automated method that specifies the optimal spectral ranges under the given illumination. Experimental results verify the consistent performance of our algorithm via …