Physical Sciences and Mathematics Commons^™

A Simplified Model For Growth Factor Induced Healing Of Wounds, F. J. Vermolen, E. Van Baaren, J. A. Adam

Mathematics & Statistics Faculty Publications

A mathematical model is developed for the rate of healing of a circular or elliptic wound. In this paper the regeneration, decay and transport of a generic 'growth factor', which induces the healing of the wound, is taken into account. Further, an equation of motion is derived for radial healing of a circular wound. The expressions for the equation of motion and the distribution of the growth factor are related in such a way that no healing occurs if the growth factor concentration at the wound edge is below a threshold value. In this paper we investigate the influence of …

An Adaptive Algorithm To Identify Ambiguous Prostate Capsule Boundary Lines For Three-Dimensional Reconstruction And Quantitation, Rania Yousry Hussein

Electrical & Computer Engineering Theses & Dissertations

Currently there are few parameters that are used to compare the efficiency of different methods of cancerous prostate surgical removal. An accurate assessment of the percentage and depth of extra-capsular soft tissue removed with the prostate by the various surgical techniques can help surgeons determine the appropriateness of surgical approaches. Additionally, an objective assessment can allow a particular surgeon to compare individual performance against a standard. In order to facilitate 3D reconstruction and objective analysis and thus provide more accurate quantitation results when analyzing specimens, it is essential to automatically identify the capsule line that separates the prostate gland tissue …

Learning As A Nonlinear Line Of Attraction For Pattern Association, Classification And Recognition, Ming-Jung Seow

Electrical & Computer Engineering Theses & Dissertations

Development of a mathematical model for learning a nonlinear line of attraction is presented in this dissertation, in contrast to the conventional recurrent neural network model in which the memory is stored in an attractive fixed point at discrete location in state space. A nonlinear line of attraction is the encapsulation of attractive fixed points scattered in state space as an attractive nonlinear line, describing patterns with similar characteristics as a family of patterns.

It is usually of prime imperative to guarantee the convergence of the dynamics of the recurrent network for associative learning and recall. We propose to alter …

New Fellow: Robert A. Willis, Jr.

Virginia Journal of Science

Robert A. Willis, Jr. has been named Fellow of the Virginia Academy of Science. He has been an active member of the Virginia Academy of Science and the Association of Departments of Computer, Information Science/Engineering at Minority Institutions (ADMI) for nearly fifteen years.

Hessian Matrix-Free Lagrange-Newton-Krylov-Schur-Schwarz Methods For Elliptic Inverse Problems, Widodo Samyono

Mathematics & Statistics Theses & Dissertations

This study focuses on the solution of inverse problems for elliptic systems. The inverse problem is constructed as a PDE-constrained optimization, where the cost function is the L² norm of the difference between the measured data and the predicted state variable, and the constraint is an elliptic PDE. Particular examples of the system considered in this stud, are groundwater flow and radiation transport. The inverse problems are typically ill-posed due to error in measurements of the data. Regularization methods are employed to partially alleviate this problem. The PDE-constrained optimization is formulated as the minimization of a Lagrangian functional, formed …

A Comparative Analysis Of Air-To-Ground Engagement Outcomes In The Joint Warfare System (Jwars) And The Jwars-Joint Semi-Automated Forces Federation, Melissa Anne St. Peter

Computational Modeling & Simulation Engineering Theses & Dissertations

Multi-resolution modeling is the process by which a single model is created by connecting multiple individual models to describe phenomena at different levels of resolution [1]. "When we change resolutions, replacing a detailed model by a more aggregate one, we must ask whether results are 'consistent'" [2].

There are many methods of determining if the results of two simulations are 'consistent'. However, they are very entailed and require a detailed understanding of the individual models including their functionality, algorithms, and inner workings. A straight forward and rapid way of assessing potential inconsistencies is through a statistical comparison of the model …

Whole Word Phonetic Displays For Speech Articulation Training, Fansheng Meng

Electrical & Computer Engineering Theses & Dissertations

The main objective of this dissertation is to investigate and develop speech recognition technologies for speech training for people with hearing impairments. During the course of this work, a computer aided speech training system for articulation speech training was also designed and implemented. The speech training system places emphasis on displays to improve children's pronunciation of isolated Consonant-Vowel-Consonant (CVC) words, with displays at both the phonetic level and whole word level. This dissertation presents two hybrid methods for combining Hidden Markov Models (HMMs) and Neural Networks (NNs) for speech recognition. The first method uses NN outputs as posterior probability estimators …

An Implicit Level Set Model For Firespread, Pallop Huabsomboon

Mathematics & Statistics Theses & Dissertations

The level set method is a mathematical and computational, technique for tracking a moving interface over time. It can naturally handle topological changes such as merging or breaking interfaces. Intrinsic geometric properties of the interface, such as curvature and normal direction, are easily determined from the level set function &phis;. There are many applications of the level set method, including kinetic crystal growth, epitaxial growth of thin films, image restoration, vortex dominated flows, and so forth. Most applications described in the growing literature on the applications of level sets advance the level set equation with explicit time integration. Hence, small …

A Tabu Search Algorithm To Minimize The Makespan For The Unrelated Parallel Machines Scheduling Problem With Setup Times, Magdy Helal, Ghaith Rabadi, Ameer Al-Salem

Engineering Management & Systems Engineering Faculty Publications

In this paper we propose a tabu search implementation to solve the unrelated parallel machines scheduling problem with sequence- and machine- dependent setup times to minimize the schedules makespan. The problem is NP-hard and finding an optimal solution efficiently is unlikely. Therefore, heuristic techniques are more appropriate to find near-optimal solutions. The proposed tabu search algorithm uses two phases of perturbation schemes: the intra-machine perturbation, which optimizes the sequence of jobs on the machines, and the inter-machine perturbation, which balances the assignment of the jobs to the machines. We compare the proposed algorithm to an existing one that addressed the …

The Formal Laplace-Borel Transform Of Fliess Operators And The Composition Product, Yaqin Li, W. Steven Gray

Electrical & Computer Engineering Faculty Publications

The formal Laplace-Borel transform of an analytic integral operator, known as a Fliess operator, is defined and developed. Then, in conjunction with the composition product over formal power series, the formal Laplace-Borel transform is shown to provide an isomorphism between the semigroup of all Fliess operators under operator composition and the semigroup of all locally convergent formal power series under the composition product. Finally, the formal Laplace-Borel transform is applied in a systems theory setting to explicitly derive the relationship between the formal Laplace transform of the input and output functions of a Fliess operator. This gives a compact interpretation …

Hybrid Committee Classifier For A Computerized Colonic Polyp Detection System, Jiang Li, Jianhua Yao, Nicholas Petrick, Ronald M. Summers, Amy K. Hara, Joseph M. Reinhardt (Ed.), Josien P.W. Pluim (Ed.)

Electrical & Computer Engineering Faculty Publications

We present a hybrid committee classifier for computer-aided detection (CAD) of colonic polyps in CT colonography (CTC). The classifier involved an ensemble of support vector machines (SVM) and neural networks (NN) for classification, a progressive search algorithm for selecting a set of features used by the SVMs and a floating search algorithm for selecting features used by the NNs. A total of 102 quantitative features were calculated for each polyp candidate found by a prototype CAD system. 3 features were selected for each of 7 SVM classifiers which were then combined to form a committee of SVMs classifier. Similarly, features …

Ontological Implications Of The Levels Of Conceptual Interoperability Model, Andreas Tolk, Charles D. Turnitsa, Saikou Y. Diallo

Computational Modeling & Simulation Engineering Faculty Publications

The Levels of Conceptual Interoperability Model (LCIM) was developed to cope with the different layers of interoperation of modeling & simulation applications. It introduced technical, syntactic, semantic, pragmatic, dynamic, and conceptual layers of interoperation and showed how they are related to the ideas of integratability, interoperability, and composability. This paper will be presented in the invited session "Ontology Driven Interoperability for Agile Applications using Information Systems: Requirements and Applications for Agent Mediated Decision Support" at WMSCI 2006.

Fedcor: An Institutional Cordra Registry, Giridhar Manepalli, Henry Jerez, Michael L. Nelson

Computer Science Faculty Publications

FeDCOR (Federation of DSpace using CORDRA) is a registry-based federation system for DSpace instances. It is based on the CORDRA model. The first article in this issue of D-Lib Magazine describes the Advanced Distributed Learning-Registry (ADL-R) [1], which is the first operational CORDRA registry, and also includes an introduction to CORDRA. That introduction, or other prior knowledge of the CORDRA effort, is recommended for the best understanding of this article, which builds on that base to describe in detail the FeDCOR approach.

Template-Based Metadata Extraction For Heterogeneous Collection, Jianfeng Tang

Computer Science Theses & Dissertations

With the growth of the Internet and related tools, there has been a rapid growth of online resources. In particular, by using high-quality OCR (Optical Character Recognition) tools it has become easy to convert an existing corpus into digital form and make it available online. However, a number of organizations have legacy collections that lack metadata. The lack of metadata hampers not only the discovery and dispersion of these collections over the Web, but also their interoperability with other collections. Unfortunately, manual metadata creation is expensive and time-consuming for a large collection, and most existing automated metadata extraction approaches have …

Group Key Management In Wireless Ad-Hoc And Sensor Networks, Mohammed A. Moharrum

Computer Science Theses & Dissertations

A growing number of secure group applications in both civilian and military domains is being deployed in WAHNs. A Wireless Ad-hoc Network (WARN) is a collection of autonomous nodes or terminals that communicate with each other by forming a multi-hop radio network and maintaining connectivity in a decentralized manner. A Mobile Ad-hoc Network (MANET) is a special type of WARN with mobile users. MANET nodes have limited communication, computational capabilities, and power. Wireless Sensor Networks (WSNs) are sensor networks with massive numbers of small, inexpensive devices pervasive throughout electrical and mechanical systems and ubiquitous throughout the environment that monitor and …

Observed Web Robot Behavior On Decaying Web Subsites, Joan A. Smith, Frank Mccown, Michael L. Nelson

Computer Science Faculty Publications

We describe the observed crawling patterns of various search engines (including Google, Yahoo and MSN) as they traverse a series of web subsites whose contents decay at predetermined rates. We plot the progress of the crawlers through the subsites, and their behaviors regarding the various file types included in the web subsites. We chose decaying subsites because we were originally interested in tracking the implication of using search engine caches for digital preservation. However, some of the crawling behaviors themselves proved to be interesting and have implications on using a search engine as an interface to a digital library.

Splai: Computational Finite Element Model For Sensor Networks, Ruzana Ishak, Shadaruddin Salleh, Stephan Olariu, Mohd.Ismail Abdul Aziz

Computer Science Faculty Publications

Wireless sensor network refers to a group of sensors, linked by a wireless medium to perform distributed sensing task. The primary interest is their capability in monitoring the physical environment through the deployment of numerous tiny, intelligent, wireless networked sensor nodes. Our interest consists of a sensor network, which includes a few specialized nodes called processing elements that can perform some limited computational capabilities. In this paper, we propose a model called SPLAI that allows the network to compute a finite element problem where the processing elements are modeled as the nodes in the linear triangular approximation problem. Our model …

Synchronization And Multiple Group Server Support For Kepler, K. Maly, M. Zubair, H. Siripuram, S. Zunjarwad, Yannis Manolopoulos (Ed.), Joaquim Filipe (Ed.), Panos Constantopoulos (Ed.), José Cordeiro (Ed.)

Computer Science Faculty Publications

In the last decade literally thousands of digital libraries have emerged but one of the biggest obstacles for dissemination of information to a user community is that many digital libraries use different, proprietary technologies that inhibit interoperability. Kepler framework addresses interoperability and gives publication control to individual publishers. In Kepler, OAI-PMH is used to support "personal data providers" or "archivelets".". In our vision, individual publishers can be integrated with an institutional repository like Dspace by means of a Kepler Group Digital Library (GDL). The GDL aggregates metadata and full text from archivelets and can act as an OAI-compliant data provider …

A Dyadic Composition To Foster Virtual Team Effectiveness: An Experimental Study, Gamze Karayaz

Engineering Management & Systems Engineering Theses & Dissertations

The importance of effectiveness for virtual teamwork continues to gain momentum as technology and globalization of work accelerate. The implementation of virtual teams provides one approach to enhance competitiveness, overcoming the disadvantages of space and time differences through collaborative technologies. The influence of structure to virtual team performance has not been clearly established in the literature. The purpose of this research study was to investigate the effectiveness of a dyad structured approach for virtual teams using a quasi-experimental research design.

This research investigated four questions related to the influence of structure on virtual team effectiveness related to task performance, communication …