Digital Commons Network^™

Autonomous Vehicle Technologies For Small Fixed Wing Uavs, Derek B. Kingston, Randal Beard, Timothy Mclain, Michael Larsen, Wei Ren

Faculty Publications

Autonomous unmanned air vehicle flight control systems require robust path generation to account for terrain obstructions, weather, and moving threats such as radar, jammers, and unfriendly aircraft. In this paper, we outline a feasible, hierarchal approach for real-time motion planning of small autonomous fixed-wing UAVs. The approach divides the trajectory generation into four tasks: waypoint path planning, dynamic trajectory smoothing, trajectory tracking, and low-level autopilot compensation. The waypoint path planner determines the vehicle's route without regard for the dynamic constraints of the vehicle. This results in a significant reduction in the path search space, enabling the generation of complicated paths …

Modular Verification Of Timed Circuits Using Automatic Abstraction, Eric G. Mercer, Chris Myers, Hao Zheng

Faculty Publications

The major barrier that prevents the application of formal verification to large designs is state explosion. This paper presents a new approach for verification of timed circuits using automatic abstraction. This approach partitions the design into modules, each with constrained complexity. Before verification is applied to each individual module, irrelevant information to the behavior of the selected module is abstracted away. This approach converts a verification problem with big exponential complexity to a set of subproblems, each with small exponential complexity. Experimental results are promising in that they indicate that our approach has the potential of completing much faster while …

Dynamic Sociometry In Particle Swarm Optimization, Mark Richards, Dan A. Ventura

Faculty Publications

The performance of Particle Swarm Optimization is greatly affected by the size and sociometry of the swarm. This research proposes a dynamic sociometry, which is shown to be more effective on some problems than the standard star and ring sociometries. The performance of various combinations of swarm size and sociometry on six different test functions is qualitatively analyzed.

A Study Of Radiofrequency Cardiac Ablation Using Analytical And Numerical Techniques, Ryan Todd Roper

Theses and Dissertations

Studies on radiofrequency (RF) ablation are often aimed at accurately predicting tissue temperature distributions by numerical solution of the bioheat equation. This thesis describes the development of an analytical solution to serve as a benchmark for subsequent numerical solutions. The solution, which was obtained using integral transforms, has the form of a surface integral nested within another surface integral. An integration routine capable of evaluating such integrals was developed and a C program was written to implement this routine. The surface integration routine was validated using a surface integral with a known analytical solution. The routine was, then, used to …

First-Principles Calculations For Nitrogen-Containing Single-Walled Carbon Nanotubes, James P. Lewis, Mingwen Zhao, Yueyugan Xia, Ruiqin Zhang

Faculty Publications

We present calculations for possible configurations of nitrogen-containing single-walled carbon nanotubes and their electronic properties obtained with the ab initio tight-binding FIREBALL method. It is found that nitrogen atoms can be energetically incorporated into the carbon network in three forms: Substitution, substitution with formation of a vacancy structure, and chemical adsorption. The different forms exhibit different local densities of states near the Fermi levels, which might suggest a potential method to control the electronic properties of nitrogen-doped carbon nanotubes

Incorporating Functionally Graded Materials And Precipitation Hardening Into Microstructure Sensitive Design, Mark Edward Lyon

Theses and Dissertations

The methods of MSD are applied to the design of functionally graded materials. Analysis models are presented to allow the design of compliant derailleur for a case study and constraints are placed on the design. Several methods are presented for relating elements of the microstructure to the properties of the material, including Taylor yield theory, Hill elastic bounds, and precipitation hardening.

Applying n-point statistics to the MSD framework is also discussed. Some results are presented for the information content of the 2-point correlation statistics that follow from the methods used to integrate functionally graded materials into MSD.

For the compliant …

Geobotany Of The Niobrara Chalk Barrens In Colorado: A Study Of Edaphic Endemism, Sylvia Kelso, Nathan W. Bower, Kirsten E. Heckmann, Paul M. Beardsley, Darren G. Greve

Western North American Naturalist

The chalk barrens of the Niobrara Formation in the Arkansas River valley of Colorado exhibit a high degree of plant endemism and rarity. We examined their geochemistry and structure as well as the reproductive ecology of their signature species Mirabilis rotundifolius to assess factors influencing endemism. While no single component consistently identified the barren soils, the natural locations that support Mirablilis can be identified using elemental profiles from a cluster analysis of soil extracts. Because seeds germinate and plants proliferate in transplant gardens with non-calcic soils, bedrock and soil chemistry do not appear to be determinant components of endemism. Mirabilis …

Consensus-Based Table Form Recognition, William A. Barrett, Heath E. Nielson

Faculty Publications

Zoning documents increases the resolution of indexing from the image level to the field level. A line-delimited tabular document forms a well defined series of regions. However, as image quality decreases, accurate zoning becomes increasingly difficult. Given a sequence of documents with the same layout, we present a robust zoning method which exploits both intra- and inter-document consensus to form a more accurate combined result (template) that can be applied to any other document with the same layout.

Just-In-Time Browsing For Digitized Microfilm And Other Similar Image Collections, William A. Barrett, Douglas J. Kennard

Faculty Publications

This paper describes “Just-In-Time Browsing” (JITB), a method for image browsing (at modem-like speed) in which image data is transmitted and presented to the user progressively, in prioritized order, based on image content and user interaction. Spatial resolution and grayscale or color fidelity is increased first for the portions of the image that are immediately of most interest to the user. JITB is specifically geared toward digitized microfilm and other similar document image collections, although it can also be used for other types of images. A series of common browsing tasks performed by multiple users demonstrates that JITB compares favorably …

Learning Real-Time A* Path Planner For Sensing Closely-Spaced Targets From An Aircraft, Jason K. Howlett, Michael A. Goodrich, Timothy W. Mclain

Faculty Publications

This work develops an any-time path planner, based on the learning real-time A* (LRTA*) search, for generating flyable paths that allow an aircraft with a specified sensor footprint to sense a group of closely-spaced targets. The LRTA* algorithm searches a tree of flyable paths for the branch that accomplishes the desired objectives in the shortest distance. The tree of paths is created by assembling primitive turn and straight sections of a specified step size. The operating parameters for the LRTA* search directly influence the running time and path-length performance of the search. A modified LRTA* search is presented that terminates …

Modeling Electromagnetic Wave Propagation In Electrically Large Structures, Jon Wallace

Theses and Dissertations

Existing unified numerical electromagnetic methods are often unable to analyze electrically large structures due to the amount of memory and processing power required, necessitating approximate analyses with limited applicability. In this research a hybrid modeling methodology is adopted to solve these complex problems more efficiently than unified numerical methods and more accurately than analytical methods. Electromagnetic modeling problems are divided into two or more levels of scale. Each level analyzes a specific level of detail and only promotes the required information to the next level. The method is demonstrated by successful application to three important problems: (1) remote sensing of …

T-Splines And T-Nurccs, Thomas W. Sederberg, Jianmin Zheng, Almaz Bakenov, Ahmad Nasri

Faculty Publications

This paper presents a generalization of non-uniform B-spline surfaces called T-splines. T-spline control grids permit T-junctions, so lines of control points need not traverse the entire control grid. T-splines support many valuable operations within a consistent framework, such as local refinement, and the merging of several B-spline surfaces that have different knot vectors into a single gap-free model. The paper focuses on T-splines of degree three, which are C2 (in the absence of multiple knots). T-NURCCs (Non-Uniform Rational Catmull-Clark Surfaces with T-junctions) are a superset of both T-splines and Catmull-Clark surfaces. Thus, a modeling program for T-NURCCs can handle any …

Multienergetic External-Beam Pixe As A Means Of Stydying The Surface Enrichment Effect In Coins, Scott Evans Perry

Theses and Dissertations

This thesis paper examines the feasibility of using external-beam PIXE to study the surface enrichment effect in metal artifacts. By varying the energy of the incident proton beam, we penetrated the artifact's surface to different levels and were able to produce a depth profile of the elemental composition of the sample. In this study, the sample set we chose to examine consisted of ancient and modern coins. This paper first describes the surface enrichment effect and theoretically how PIXE can be used to study it. It then details the construction of the components of the external-beam setup. Many of the …

Observation Of And Model For Nonlinear Mode Conversion In A Non-Neutral Plasma, Grant W. Hart, Bryan G. Peterson, Ross L. Spencer

Faculty Publications

The nonlinear interaction of the two lowest Trivelpiece-Gould modes in a non-neutral plasma has been observed. Because of coupling in the nonlinear terms of the continuity and momentum equations, the two modes can exchange energy and convert one to the other. This can be modeled using the cold fluid equations and the averaging method. Experimentally, this process always stops with the lower frequency mode dominating the final state. Numerical integration of the model suggests that this occurs because the higher frequency mode is more strongly damped than the lower frequency mode.

Identification Of Macro- And Micro-Compliant Mechanism Configurations Resulting In Bistable Behavior, Brian D. Jensen

Theses and Dissertations

The purpose of this research is to identify the configurations of several mechanism classes which result in bistable behavior. Bistable mechanisms have use in many applications, such as switches, clasps, closures, hinges, and so on. A powerful method for the design of such mechanisms would allow the realization of working designs much more easily than has been possible in the past. A method for the design of bistable mechanisms is especially needed for micro-electro-mechanical systems (MEMS) because fabrication and material constraints often prevent the use of simple, well-known bistable mechanism configurations. In addition, this knowledge allows designers to take advantage …

A Self-Retracting Fully-Compliant Bistable Micromechanism, Nathan D. Masters

Theses and Dissertations

The purpose of this research is to present a class of Self-Retracting Fully-compliant Bistable Micromechanisms (SRFBM). Fully-compliant mechanisms are needed to overcome the inherent limitations of microfabricated pin joints, especially in bistable mechanisms. The elimination of the clearances associated with pin joints will allow more efficient bistable mechanisms with smaller travel. Small travel, in a linear path facilitates integration with efficient on-chip actuators. Tensural pivots are developed and used to deal with the compressive loading to which the mechanism is subject. SRFBM are modeled using the Pseudo-Rigid-Body Model and finite element analysis. Suitable configurations of the SRFBM concept have been …

Iteration Methods For Approximating The Lowest Order Energy Eigenstate Of A Given Symmetry For One- And Two-Dimensional Systems, Chad Everett Junkermeier

Theses and Dissertations

Using the idea that a quantum mechanical system drops to its ground state as its temperature goes to absolute zero several operators are devised to enable the approximation of the lowest order energy eigenstate of a given symmetry; as well as an approximation to the energy eigenvalue of the same order.

Types Of Digital Library Cooperation In German Studies, Richard Hacken

Faculty Publications

A paper delivered at the ACRL/WESS Program in Toronto on June 23, 2003. A small sampling of the types of cooperative work being done in German studies, especially of retrospective digitization (as opposed to ongoing electronic publications).

Minimal Graphs In R3 Over Convex Domains, Michael Dorff

Faculty Publications

Krust established that all conjugate and associate surfaces of a minimal graph over a convex domain are also graphs. Using a convolution theorem from the theory of harmonic univalent mappings, we generalize Krust's theorem to include the family of convolution surfaces which are generated by taking the Hadamard product or convolution of mappings. Since this convolution involves convex univalent analytic mappings, this family of convolution surfaces is much larger than just the family of associated surfaces. Also, this generalization guarantees that all the resulting surfaces are over close-toconvex domains. In particular, all the associate surfaces and certain Goursat transformation surfaces …

The Topology Of Hyperbolic Attractors On Compact Surfaces, Todd L. Fisher

Faculty Publications

Suppose M is a compact surface and M is a nontrivial mixing hyperbolic attractor for some f 2 Diff(M). We show that if is a hyperbolic set for some g 2 Diff(M), then is a nontrivial mixing hyperbolic attractor or repeller for g.

A Self-Adapting Healthcare Information Infrastructure Using Mobile Computing Devices, James K. Archibald, Eric S. Hall, Charles D. Knutson, David K. Vawdrey

Faculty Publications

Despite recent improvements in the gathering and sharing of patient medical information among healthcare providers, there remains a gap in the electronic medical record infrastructure. Patient data is not available in some situations, either because the infrastructure is inaccessible (as in a natural disaster) or because there is no way to link the patient to the infrastructure (e.g., the patient cannot supply necessary identification information). This paper describes the Poket Doktor System, an architecture that allows an individual to carry personal electronic medical information on a wireless handheld device such as a smart card, cell phone, or PDA. Medical workers …

Detecting Lehi’S Genetic Signature: Possible, Probable, Or Not?, David A. Mcclellan

Review of Books on the Book of Mormon 1989–2011

No abstract provided.

Appendix, On Aping Aristotle: Modern-Day Simplicios, Glen M. Cooper

Review of Books on the Book of Mormon 1989–2011

No abstract provided.

Elusive Israel And The Numerical Dynamics Of Population Mixing, Brian D. Stubbs

Review of Books on the Book of Mormon 1989–2011

No abstract provided.

The 1710 Von Graffenried Settlement Of New Bern, North Carolina, Lewis B. Rohrbach Cg

Swiss American Historical Society Review

In the following study I have endeavored to identify and document the lives and descendants of all 752 Swiss and Germans who came from Bern, Switzerland and London, England in 1710 to found New Bern , North Carolina. There were approximately 177 families in the migration traveling on three ships, of whom 51 families were Swiss, 106 were German, and approximately 20 families died out entirely on the voyage so that we do not know their names or nationality . The much better known 1710 New York settlement involved 10 ships and 847 families, but although the New Bern settlement …

Prolegomena To The Dna Articles, Daniel C. Peterson

Review of Books on the Book of Mormon 1989–2011

No abstract provided.

Trustworthy History?, Steven C. Harper

Review of Books on the Book of Mormon 1989–2011

Review of Grant H. Palmer. An Insider’s View of Mormon Origins.

Full Issue

Swiss American Historical Society Review

No abstract provided.

Dynamic Joint Action Perception For Q-Learning Agents, Nancy Fulda, Dan A. Ventura

Faculty Publications

Q-learning is a reinforcement learning algorithm that learns expected utilities for state-action transitions through successive interactions with the environment. The algorithm's simplicity as well as its convergence properties have made it a popular algorithm for study. However, its non-parametric representation of utilities limits its effectiveness in environments with large amounts of perceptual input. For example, in multiagent systems, each agent may need to consider the action selections of its counterparts in order to learn effective behaviors. This creates a joint action space which grows exponentially with the number of agents in the system. In such situations, the Q-learning algorithm quickly …

Knot Intervals And Multi-Degree Splines, Thomas W. Sederberg, Jianmin Zheng, Xiaowen Song

Faculty Publications

This paper studies the merits of using knot interval notation for B-spline curves, and presents formulae in terms of knot intervals for common B-spline operations such as knot insertion, differentiation, and degree elevation. Using knot interval notation, the paper introduces MD-splines, which are B-spline-like curves that are comprised of polynomial segments of various degrees (MD stands for \multi-degree"). MD-splines are a generalization of B-spline curves in that if all curve segments in an MD-spline have the same degree, it reduces to a B-spline curve. The paper focuses on MD-splines of degree 1, 2, and 3, as well as degree 1 …