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Full-Text Articles in Physical Sciences and Mathematics

Engineering Management Framework In Support Of Modeling & Simulation Application For Domain Specific Procurement, Thomas Guy Litwin Oct 2008

Engineering Management Framework In Support Of Modeling & Simulation Application For Domain Specific Procurement, Thomas Guy Litwin

Engineering Management & Systems Engineering Theses & Dissertations

A strategic process is desirable for project-based organizations in order for them to be efficient and effective when developing Modeling & Simulation (M&S) systems. This thesis proposes an overarching process that combines traditional M&S and Engineering Management methodologies in a new framework to support M&S organizations during the procurement process.

This thesis proposes both a Strategic Project Management Process (SPMP) and a systems engineering process for M&S federation development projects. The systems engineering process utilizes the artifacts of Model Driven Architecture (MDA) to support building M&S federations driven by operational requirements. Detailed research of this systems engineering process revealed a …


Modeling Geographic Population Dispersion Utilizing Geospatial Information System Environment Agents In An Agent Based Model, Karl D. Liebert Oct 2008

Modeling Geographic Population Dispersion Utilizing Geospatial Information System Environment Agents In An Agent Based Model, Karl D. Liebert

Computational Modeling & Simulation Engineering Theses & Dissertations

New capabilities in agent based model (ABM) environments are opening the door to the creation of ABM that may incorporate high-quality, real world environment data in the form of Geospatial Information System (GIS) files . In the past, GJS environments were only possible through extensive software development efforts focused on specific model applications.

This thesis explores the value and issues of using GIS data to provide an ABM environment. It examines the ability of ABM development environments (DE) to support GIS environment data. The selected ABM DE is then used to model population behavior in an environment defined by authoritative …


Using Timed-Release Cryptography To Mitigate Preservation Risk Of Embargo Periods, Rabia Haq Oct 2008

Using Timed-Release Cryptography To Mitigate Preservation Risk Of Embargo Periods, Rabia Haq

Computer Science Theses & Dissertations

This research defines Time-Locked Embargo, a framework designed to mitigate the Preservation Risk Interval: the preservation risk associated with embargoed scholarly material. Due to temporary access restrictions, embargoed data cannot be distributed freely and thus preserved via data refreshing during the embargo time interval. A solution to mitigate the risk of data loss has been developed by suggesting a data dissemination framework that allows data refreshing of encrypted instances of embargoed content in an open, unrestricted scholarly community. This framework has been developed by exploiting implementations of existing technologies to"time-lock" data using Timed-Release Cryptology (TRC) so that it can be …


Tools For A Preservation-Ready Web, Joan A. Smith, Michael L. Nelson Jul 2008

Tools For A Preservation-Ready Web, Joan A. Smith, Michael L. Nelson

Computer Science Presentations

PDF of a powerpoint presentation from the National Digital Information Infrastructure and Preservation Program (NDIIPP) Partners Meeting, Washington D.C., July 9, 2008. Also available on Slideshare.


Biology-Inspired Approach For Communal Behavior In Massively Deployed Sensor Networks, Kennie H. Jones Jul 2008

Biology-Inspired Approach For Communal Behavior In Massively Deployed Sensor Networks, Kennie H. Jones

Computer Science Theses & Dissertations

Research in wireless sensor networks has accelerated rapidly in recent years. The promise of ubiquitous control of the physical environment opens the way for new applications that will redefine the way we live and work. Due to the small size and low cost of sensor devices, visionaries promise smart systems enabled by deployment of massive numbers of sensors working in concert. To date, most of the research effort has concentrated on forming ad hoc networks under centralized control, which is not scalable to massive deployments. This thesis proposes an alternative approach based on models inspired by biological systems and reports …


Using Agile Software Development Practices In A Research Oriented Distributed Simulation, Douglas James Mielke Jul 2008

Using Agile Software Development Practices In A Research Oriented Distributed Simulation, Douglas James Mielke

Computational Modeling & Simulation Engineering Theses & Dissertations

Although sometimes controversial, agile methodologies have proven to be a viable choice for some software development projects. Projects suited to agile methodologies are those that involve new technology, have requirements that change rapidly, and are controlled by small, talented teams. Much literature about agile software development leans towards business products and non-government entities. Only a handful of literature resources mention agile software development being used in government contracts and even fewer resources mention research projects. NASA's Airspace and Traffic Operations Simulation (ATOS) is a research oriented simulation that doesn't follow the traditional business project mold. In an effort to gain …


Integrating Preservation Functions Into The Web Server, Joan A. Smith Jul 2008

Integrating Preservation Functions Into The Web Server, Joan A. Smith

Computer Science Theses & Dissertations

Digital preservation of theWorldWideWeb poses unique challenges, different fromthe preservation issues facing professional Digital Libraries. The complete list of a website’s resources cannot be cited with confidence, and the descriptive metadata available for the resources is so minimal that it is sometimes insufficient for a browser to recognize. In short, the Web suffers from a counting problem and a representation problem. Refreshing the bits, migrating from an obsolete file format to a newer format, and other classic digital preservation problems also affect the Web. As digital collections devise solutions to these problems, the Web will also benefit. But the core …


Real-Time Ultrasound Simulation For Medical Training And Standardized Patient Assessment, Bo Sun Apr 2008

Real-Time Ultrasound Simulation For Medical Training And Standardized Patient Assessment, Bo Sun

Computational Modeling & Simulation Engineering Theses & Dissertations

With the increasing role played by ultrasound in clinical diagnostics, ultrasound training in medical education has become more and more important. The clinical routine for ultrasound training is on real patients; therefore monitored and guided examinations involving medical students are quite time-constrained. Furthermore, standardized patients (SPs), who are increasingly used in medical school for teaching and assessing medical students, need to be augmented. These SPs are typically healthy individuals who can not accurately portray the variety of abnormalities that are needed for training especially when medical examinations involve instrument interactions. To augment SPs in a realistically effective way and also …


Parallel Mpi/Fortran Finite Element Symmetrical/Unsymmetrical Domain Decomposition, Siroj Tungkatara Apr 2008

Parallel Mpi/Fortran Finite Element Symmetrical/Unsymmetrical Domain Decomposition, Siroj Tungkatara

Civil & Environmental Engineering Theses & Dissertations

MPI/FORTRAN finite element analysis software based on Domain Decomposition (DD) formulas has been developed in this work. Efficient input data storage/data communication schemes, domain partitioning, fast symbolical and numerical sparse assembly, symmetrical/unsymmetrical sparse solver and robust symmetrical/unsymmetrical iterative solvers algorithms are all incorporated into the developed code. Parallel Precondition Conjugated Gradient (PCG) and Flexible Generalized Minimum Residual (FGMRES) are developed. Efficient computational techniques used in the developed code are explained. Numerical performance and the accuracy of the developed code are conducted on acoustic examples with medium to large grid sizes. The results obtained from ODU Wilbur cluster (under parallel processing …


A Practical Approach To Robotic Design For The Darpa Urban Challenge, Benjamin J. Patz, Yiannis Papelis, Remo Pillat, Gary Stein, Don Harper Jan 2008

A Practical Approach To Robotic Design For The Darpa Urban Challenge, Benjamin J. Patz, Yiannis Papelis, Remo Pillat, Gary Stein, Don Harper

VMASC Publications

This article presents a practical approach to engineering a robot to effectively navigate in an urban environment. Inherent in this approach is the use of relatively simple sensors, actuators, and processors to generate robot vision, intelligence, and planning. Sensor data are fused from multiple low-cost, two-dimensional laser scanners With an innovative rotational mount to provide three-dimensional coverage with image processing using both range and intensity data. Information is combined With Doppler radar returns to yield a world view processed by a context-based reasoning control system to yield tactical mission commands forwarded to traditional proportional-integral-derivative (PID) control loops. As an example …


Emergent Behavior In Massively-Deployed Sensor Networks, Ekaterina Shurkova, Ruzana Ishak, Stephan Olariu, Shaharuddin Salleh Jan 2008

Emergent Behavior In Massively-Deployed Sensor Networks, Ekaterina Shurkova, Ruzana Ishak, Stephan Olariu, Shaharuddin Salleh

Computer Science Faculty Publications

The phenomenal advances in MEMS and nanotechnology make it feasible to build small devices, referred to as sensors that are able to sense, compute and communicate over small distances. The massive deployment of these small devices raises the fascinating question of whether or not the sensors, as a collectivity, will display emergent behavior, just as living organisms do. In this work we report on a recent effort intended to observe emerging behavior of large groups of sensor nodes, like living cells demonstrate. Imagine a massive deployment of sensors that can be in two states "red" and "blue". At deployment time …


Efficient Corona Training Protocols For Sensor Networks, Alan A. Bertossi, Stephan Olariu, Cristina M. Pinotti Jan 2008

Efficient Corona Training Protocols For Sensor Networks, Alan A. Bertossi, Stephan Olariu, Cristina M. Pinotti

Computer Science Faculty Publications

Phenomenal advances in nano-technology and packaging have made it possible to develop miniaturized low-power devices that integrate sensing, special-purpose computing, and wireless communications capabilities. It is expected that these small devices, referred to as sensors, will be mass-produced and deployed, making their production cost negligible. Due to their small form factor and modest non-renewable energy budget, individual sensors are not expected to be GPS-enabled. Moreover, in most applications, exact geographic location is not necessary, and all that the individual sensors need is a coarse-grain location awareness. The task of acquiring such a coarse-grain location awareness is referred to as training. …


Rapid Prototyping For Virtual Environments, Emre Baydogan Jan 2008

Rapid Prototyping For Virtual Environments, Emre Baydogan

Electrical & Computer Engineering Theses & Dissertations

Development of Virtual Environment (VE) applications is challenging where application developers are required to have expertise in the target VE technologies along with the problem domain expertise. New VE technologies impose a significant learning curve to even the most experienced VE developer. The proposed solution relies on synthesis to automate the migration of a VE application to a new unfamiliar VE platform/technology. To solve the problem, the Common Scene Definition Framework (CSDF) is developed, that serves as a superset/model representation of the target virtual world. Input modules are developed to populate the framework with the capabilities of the virtual world …


Biological Networks: Modeling And Structural Analysis, Emad Y. Ramadan Jan 2008

Biological Networks: Modeling And Structural Analysis, Emad Y. Ramadan

Computer Science Theses & Dissertations

Biological networks are receiving increased attention due to their importance in understanding life at the cellular level. There exist many different kinds of biological networks, and different models have been proposed for them. In this dissertation we focus on suitable network models for representing experimental data on protein interaction networks and protein complex networks (protein complexes are groups of proteins that associate to accomplish some function in the cell), and to design algorithms for exploring such networks. Our goal is to enable biologists to identify the general principles that govern the organization of protein-protein interaction networks and protein complex networks. …


Creating Preservation-Ready Web Resources, Joan A. Smith, Michael L. Nelson Jan 2008

Creating Preservation-Ready Web Resources, Joan A. Smith, Michael L. Nelson

Computer Science Faculty Publications

There are innumerable departmental, community, and personal web sites worthy of long-term preservation but proportionally fewer archivists available to properly prepare and process such sites. We propose a simple model for such everyday web sites which takes advantage of the web server itself to help prepare the site's resources for preservation. This is accomplished by having metadata utilities analyze the resource at the time of dissemination. The web server responds to the archiving repository crawler by sending both the resource and the just-in-time generated metadata as a straight-forward XML-formatted response. We call this complex object (resource + metadata) a CRATE. …


Nonlinear Random Response Of Large-Scale Sparse Finite Element Plate Bending Problems, Swati Chokshi Jan 2008

Nonlinear Random Response Of Large-Scale Sparse Finite Element Plate Bending Problems, Swati Chokshi

Civil & Environmental Engineering Theses & Dissertations

Acoustic fatigue is one of the major design considerations for skin panels exposed to high levels of random pressure at subsonic/supersonic/hypersonic speeds. The nonlinear large deflection random response of the single-bay panels aerospace structures subjected to random excitations at various sound pressure levels (SPLs) is investigated. The nonlinear responses of plate analyses are limited to determine the root-mean-square displacement under uniformly distributed pressure random loads. Efficient computational technologies like sparse storage schemes and parallel computation are proposed and incorporated to solve large-scale, nonlinear large deflection random vibration problems for both types of loading cases: (1) synchronized in time and (2) …


Towards A Metric For The Assessment Of Safety Critical Control Systems, Oscar R. Gonzalez, Jorge R. Chavez-Fuentes, W. Steven Gray Jan 2008

Towards A Metric For The Assessment Of Safety Critical Control Systems, Oscar R. Gonzalez, Jorge R. Chavez-Fuentes, W. Steven Gray

Electrical & Computer Engineering Faculty Publications

There is a need for better integration of the fault tolerant and the control designs for safety critical systems such as aircraft. The dependability of current designs is assessed primarily with measures of the interconnection of fault tolerant components: the reliability function and the mean time to failure. These measures do not directly take into account the interaction of the fault tolerant components with the dynamics of the aircraft. In this paper, a first step to better integrate these designs is made. It is based on the observation that unstable systems are intrinsically unreliable and that a necessary condition for …


Vegetation Identification Based On Satellite Imagery, Vamsi K.R. Mantena, Ramu Pedada, Srinivas Jakkula, Yuzhong Shen, Jiang Li, Hamid R. Arabnia (Ed.) Jan 2008

Vegetation Identification Based On Satellite Imagery, Vamsi K.R. Mantena, Ramu Pedada, Srinivas Jakkula, Yuzhong Shen, Jiang Li, Hamid R. Arabnia (Ed.)

Electrical & Computer Engineering Faculty Publications

Automatic vegetation identification plays an important role in many applications including remote sensing and high performance flight simulations. This paper presents a method to automatically identify vegetation based upon satellite imagery. First, we utilize the ISODATA algorithm to cluster pixels in the images where the number of clusters is determined by the algorithm. We then apply morphological operations to the clustered images to smooth the boundaries between clusters and to fill holes inside clusters. After that, we compute six features for each cluster. These six features then go through a feature selection algorithm and three of them are determined to …