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Articles 2101 - 2130 of 2906

Full-Text Articles in Physical Sciences and Mathematics

A Constructive Incremental Learning Algorithm For Binary Classification Tasks, Christophe G. Giraud-Carrier, Tony R. Martinez Jul 2006

A Constructive Incremental Learning Algorithm For Binary Classification Tasks, Christophe G. Giraud-Carrier, Tony R. Martinez

Faculty Publications

This paper presents i-AA1*, a constructive, incremental learning algorithm for a special class of weightless, self-organizing networks. In i-AA1*, learning consists of adapting the nodes’ functions and the network’s overall topology as each new training pattern is presented. Provided the training data is consistent, computational complexity is low and prior factual knowledge may be used to “prime” the network and improve its predictive accuracy. Empirical generalization results on both toy problems and more realistic tasks demonstrate promise.

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The Provenance Of Eocene Tuff Beds In The Fossil Butte Member Of The Green River Formation Of Wyoming: Relation To The Absaroka And Challis Volcanic Fields, Matthew R. Chandler Jul 2006

The Provenance Of Eocene Tuff Beds In The Fossil Butte Member Of The Green River Formation Of Wyoming: Relation To The Absaroka And Challis Volcanic Fields, Matthew R. Chandler

Theses and Dissertations

The Green River Formation was deposited between 53.5 and 48.5 Ma. The Angelo, Fossil Butte, and Lower members of the Green River Formation at Fossil Basin, preserve ash fall tuffs deposited in ancient Fossil Lake. 40Ar/39Ar dating of sanidine yielded eruptive ages of 51.29 ± 1.29 Ma and 52.20 ± 3.08 Ma for two of the tuff beds within Fossil Basin. Immobile element and mineral compositions of Fossil Basin tuffs indicate that most tuffs erupted from a subduction zone originally as rhyolites and dacites. X-ray diffraction analyses reveal that the tuffs' glassy matrices have been altered to illite, calcite, clinoptilolite, …

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Vectorization Of Raster Images Using B-Spline Surfaces, Curtis A. Armstrong Jul 2006

Vectorization Of Raster Images Using B-Spline Surfaces, Curtis A. Armstrong

Theses and Dissertations

A system has been developed for converting raster images into vector images. Raster images are made of pixels, while vector images are made of smoother shapes. The image is first segmented, and the segments are layered. The boundary of each segment is approximated with a periodic B-Spline curve. This curve is then used to create a B-Spline surface to approximate the interior of the segment. The algorithm fits each B-Spline to the colors of the image using least-squares approximation. The color and shape of each B-Spline surface are extrapolated into regions behind other segments. The result is a vector image …

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Optimization Of Active Noise Control For Small Axial Cooling Fans, Brian B. Monson Jul 2006

Optimization Of Active Noise Control For Small Axial Cooling Fans, Brian B. Monson

Theses and Dissertations

Previous work has shown that active noise control is a feasible solution to attenuate tonal noise radiated by small axial cooling fans, such as those found in desktop computers. One such control system reduced noise levels of a baffled 80-mm fan in the free field with four small loudspeakers surrounding the fan. Due to industry specified spatial constraints, a smaller fan and speaker configuration was desirable. The smaller configuration maintains similar control performance, further facilitating practical implementation of the control system. The smaller control system employs a smaller fan running at a higher speed. Different loudspeaker configurations for control exist …

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Characterizing Dynamic Power And Data Rate Policies For Wirelessusb Networks, Jeffrey L. Barlow Jul 2006

Characterizing Dynamic Power And Data Rate Policies For Wirelessusb Networks, Jeffrey L. Barlow

Theses and Dissertations

Wireless communication is increasingly ubiquitous. However, mobility depends intrinsically on battery life. Power can be conserved at the Media Access Control (MAC) layer by intelligently adjusting transmission power level and data rate encoding. WirelessUSB is a low-power, low-latency wireless technology developed by Cypress Semiconductor Corporation for human interface devices such as keyboards and mice. WirelessUSB devices conserve power by employing power-efficient hardware, dynamic power level adjustment and dynamic data rate adjustment. We characterize the effects on power consumption of dynamically adjusting node power using two dynamic power negotiation techniques as well as two reactive techniques. We also characterize the effects …

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The Effect Of Protein Dielectric Coefficient On The Ionic Selectivity Of A Calcium Channel, Douglas Henderson, Dezso Boda, Monika Valisko, Bob Eisenberg, Wolfgang Nonner, Dirk Gillespie Jul 2006

The Effect Of Protein Dielectric Coefficient On The Ionic Selectivity Of A Calcium Channel, Douglas Henderson, Dezso Boda, Monika Valisko, Bob Eisenberg, Wolfgang Nonner, Dirk Gillespie

Faculty Publications

Calcium-selective ion channels are known to have carboxylate-rich selectivity filters, a common motif that is primarily responsible for their high Ca2+ affinity. Different Ca2+ affinities ranging from micromolar (the L-type Ca channel) to millimolar (the ryanodine receptor channel) are closely related to the different physiological functions of these channels. To understand the physical mechanism for this range of affinities given similar amino acids in their selectivity filters, we use grand canonical Monte Carlo simulations to assess the binding of monovalent and divalent ions in the selectivity filter of a model Ca channel. We use a reduced model where the electrolyte …

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Particle Swarm Optimization In Dynamic Pricing, Christopher K. Monson, Patrick B. Mullen, Kevin Seppi, Sean C. Warnick Jul 2006

Particle Swarm Optimization In Dynamic Pricing, Christopher K. Monson, Patrick B. Mullen, Kevin Seppi, Sean C. Warnick

Faculty Publications

Dynamic pricing is a real-time machine learning problem with scarce prior data and a concrete learning cost. While the Kalman Filter can be employed to track hidden demand parameters and extensions to it can facilitate exploration for faster learning, the exploratory nature of Particle Swarm Optimization makes it a natural choice for the dynamic pricing problem. We compare both the Kalman Filter and existing particle swarm adaptations for dynamic and/or noisy environments with a novel approach that time-decays each particle's previous best value; this new strategy provides more graceful and effective transitions between exploitation and exploration, a necessity in the …

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Cooperation-Based Clustering For Profit-Maximizing Organizational Design, Christophe G. Giraud-Carrier, Kevin Seppi, Nghia Tran, Sean C. Warnick Jul 2006

Cooperation-Based Clustering For Profit-Maximizing Organizational Design, Christophe G. Giraud-Carrier, Kevin Seppi, Nghia Tran, Sean C. Warnick

Faculty Publications

This paper shows how the notion of value of cooperation, a measure of the percentage of a firm’s profits due strictly to the cooperative effects among the goods it sells, can be used to analyze the relative economic advantage afforded by various organizational structures. The value of cooperation is computed from transactions data by solving a regression problem to fit the parameters of the consumer demand function, and then simulating the resulting profit-maximizing dynamic system under various organizational structures. A hierarchical agglomerative clustering algorithm can be applied to reveal the optimal organizational substructure.

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On The N-Body Problem, Zhifu Xie Jul 2006

On The N-Body Problem, Zhifu Xie

Theses and Dissertations

In this thesis, central configurations, regularization of Simultaneous binary collision, linear stability of Kepler orbits, and index theory for symplectic path are studied. The history of their study is summarized in section 1. Section 2 deals with the following problem: given a collinear configuration of 4 bodies, under what conditions is it possible to choose positive masses which make it central. It is always possible to choose three positive masses such that the given three positions with the masses form a central configuration. However, for an arbitrary configuration of 4 bodies, it is not always possible to find positive masses …

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Knots Not For Naught, Sharleen Adrienne Roberts Jul 2006

Knots Not For Naught, Sharleen Adrienne Roberts

Theses and Dissertations

The goal of this paper is to find the Homfly polynomial for each knot in a specific family of knots. This family of knots is generated from placing the Whitehead link into a solid torus, slicing the torus at a spot where the Whitehead has no crossings and then twisting the torus 360 degrees in either direction an integral number of times. Let L(n) denote the knot obtained by twisting the torus 360 degrees, n times. Note that n is an integer. Let the twists be towards the center of the torus for positive n and away from the center …

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Local Url Resolution Protocol, Joseph Clark Ekstrom Jul 2006

Local Url Resolution Protocol, Joseph Clark Ekstrom

Theses and Dissertations

DOGMA is a resource management system designed to create a supercomputer like system from unused desktop computers. Scalability is one of the challenges faced by DOGMA because it uses a strict client/server architecture. Distributing large files over a client server architecture is problematic since available network bandwidth is limited. The Local URL Resolution Protocol(LURP) addresses this problem for environments where there are high node densities. LURP implements a locality aware Peer-to-Peer file distribution model to increase the speed of file distribution while reducing the overall network congestion.

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A Microformatted Registry Alternative, Thomas R. Warne Jul 2006

A Microformatted Registry Alternative, Thomas R. Warne

Theses and Dissertations

To effectively use Web services, providers and consumers need to be connected by a registry. Several registry solutions exist today, including UDDI and WSIL. Also, many organizations simply use Web pages to list available Web services and their descriptions. This research describes a microformat for representing Web service description documents. These microformatted documents can be converted back to the original format for use by machines. They can also contain additional information, making them more useful to people. A registry, allowing indexing and searching of microformatted service descriptions, is also described. The benefits of this solution include: using existing standards; allowing …

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Conjugacy Classes Of The Piecewise Linear Group, Matthew L. Housley Jul 2006

Conjugacy Classes Of The Piecewise Linear Group, Matthew L. Housley

Theses and Dissertations

The piecewise linear group is the set of all piecewise linear orientation preserving homeomorphisms from the interval to itself under the operation of composition. We present here a complete set of invariants to classify the conjugacy classes of this group. Our approach to this problem relies on the factorization of elements into elements having only a single breakpoint.

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Topics On The Spectral Theory Of Automorphic Forms, Dustin David Belt Jul 2006

Topics On The Spectral Theory Of Automorphic Forms, Dustin David Belt

Theses and Dissertations

We study the analytic properties of the Eisenstein Series of $frac {1}{2}$-integral weight associated with the Hecke congruence subgroup $Gamma_0(4)$. Using these properties we obtain asymptotics for sums of certain Dirichlet $L$-series. We also obtain a formula reducing the study of Selberg's Eigenvalue Conjecture to the study of the nonvanishing of the Eisenstein Series $E(z,s)$ for Hecke congruence subgroups $Gamma_0(N)$ at $s=frac {1+i}{2}$.

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Understanding Brigham Young University's Technology Teacher Education Program's Sucess In Attracting And Retaining Female Students, Katrina M. Cox Jul 2006

Understanding Brigham Young University's Technology Teacher Education Program's Sucess In Attracting And Retaining Female Students, Katrina M. Cox

Theses and Dissertations

The purpose of the study was to attempt to understand why Brigham Young University Technology Teacher Education program has attracted and retained a high number of females. This was done through a self-created survey composed of four forced responses, distributed among the Winter 2006 semester students. Likert-scale questions were outlined according to the five theoretical influences on women in technology, as established by Welty and Puck (2001) and two of the three relationships of academia, as established by Haynie III (1999), as well as three free response questions regarding retention and attraction within the major. Findings suggested strong positive polarity …

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Jumpstarting Phylogenetic Searches, Jesse Lewis Mecham Jul 2006

Jumpstarting Phylogenetic Searches, Jesse Lewis Mecham

Theses and Dissertations

Phylogenetic analysis is a central tool in studies of comparative genomics. When a new region of DNA is isolated and sequenced, researchers are often forced to throw away months of computation on an existing phylogeny of homologous sequences in order to incorporate this new sequence. The previously constructed trees are often discarded, and the researcher begins the search again from scratch. The jumpstarting algorithm uses trees from the prior search as a starting point for a new phylogenetic search. This technique drastically decreases search time for large data sets. This kind of analysis is necessary as researchers analyze tree of …

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Improving Record Linkage Through Pedigrees, Burdette N. Pixton Jul 2006

Improving Record Linkage Through Pedigrees, Burdette N. Pixton

Theses and Dissertations

Record linkage, in a genealogical context, is the process of identifying individuals from multiple sources which refer to the same real-world entity. Current solutions focus on the individuals in question and on complex rules developed by human experts. Genealogical databases are highly-structured with relationships existing between the individuals and other instances. These relationships can be utilized and human involvement greatly minimized by using a filtered structured neural network. These neural networks, using traditional back-propagation methods, are biased in a way to make the network human readable. The results show an increase in precision and recall when pedigree data is available …

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Dna-Templated Surface Alignment And Characterization Of Carbon Nanotubes., Huijun Xin Jul 2006

Dna-Templated Surface Alignment And Characterization Of Carbon Nanotubes., Huijun Xin

Theses and Dissertations

Carbon nanotubes are appealing materials for nanofabrication due to their unique properties and structures. However, for carbon nanotubes to be used in mass-fabricated devices, precise control of nanotube orientation and location on surfaces is critical. I have developed a technique to align single-walled carbon nanotubes (SWNTs) on surfaces from a droplet of nanotube suspension under gas flow. Fluid motion studies indicate that alignment is likely due to circulation of SWNTs in the droplet. My work provides a facile method for generating oriented nanotubes for nanodevice applications. I have also devised an approach for localizing SWNTs onto 1-pyrenemethylamine-decorated DNA on surfaces. …

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A Stratigraphic And Geochronologic Analysis Of The Morrison Formation/Cedar Mountain Formation Boundary, Utah, Brent W. Greenhalgh Jul 2006

A Stratigraphic And Geochronologic Analysis Of The Morrison Formation/Cedar Mountain Formation Boundary, Utah, Brent W. Greenhalgh

Theses and Dissertations

The Lower Cretaceous Cedar Mountain Formation preserves several vertebrate faunas and has the potential of providing critical timing information pertaining to Early Cretaceous dinosaurs and the Sierran magmatic arc. Historically, the Morrison/Cedar Mountain contact and the duration of the unconformity between them have been difficult or impossible to determine because 1) the formations were deposited in similar environments, 2) the basal Cedar Mountain Formation is composed of reworked Morrison Formation, and 3) there are no radiometric ages for the lower Cedar Mountain Formation. A stratigraphic study through central Utah reveals a diagnostic suite of pedogenic and sedimentologic characters across the …

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Proven Cases Of A Generalization Of Serre's Conjecture, Jonathan H. Blackhurst Jul 2006

Proven Cases Of A Generalization Of Serre's Conjecture, Jonathan H. Blackhurst

Theses and Dissertations

In the 1970's Serre conjectured a correspondence between modular forms and two-dimensional Galois representations. Ash, Doud, and Pollack have extended this conjecture to a correspondence between Hecke eigenclasses in arithmetic cohomology and n-dimensional Galois representations. We present some of the first examples of proven cases of this generalized conjecture.

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A Search For Low-Amplitude Variability Among Population I Main Sequence Stars, Michael Benjamin Rose Jul 2006

A Search For Low-Amplitude Variability Among Population I Main Sequence Stars, Michael Benjamin Rose

Theses and Dissertations

The detection of variable stars in open clusters is an essential component of testing stellar structure and evolution theories. The ability to detect low-amplitude variability among cluster members is directly related to the quality of the photometric results. Point Spread Function (PSF) fitting is the best method available for measuring accurate magnitudes within crowded fields of stars, while high-precision differential photometry is the preferred technique for removing the effects of atmospheric extinction and variable seeing. In the search for new variable stars among hundreds or thousands of stars, the Robust Median Statistic (RoMS) is proven more effective for finding low-amplitude …

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On The Combinatorics Of Certain Garside Semigroups, Christopher R. Cornwell Jul 2006

On The Combinatorics Of Certain Garside Semigroups, Christopher R. Cornwell

Theses and Dissertations

In his dissertation, F.A. Garside provided a solution to the word and conjugacy problems in the braid group on n-strands, using a particular element that he called the fundamental word. Others have since defined fundamental words in the generalized setting of Artin groups, and even more recently in Garside groups. We consider the problem of finding the number of representations of a power of the fundamental word in these settings. In the process, we find a Pascal-like identity that is satisfied in a certain class of Garside groups.

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Enhanced Electrospray Ionization For Mass Spectrometry And Ion Mobility Spectrometry, Li Zhou Jul 2006

Enhanced Electrospray Ionization For Mass Spectrometry And Ion Mobility Spectrometry, Li Zhou

Theses and Dissertations

Electrospray ionization (ESI) has become one of the most commonly used ionization techniques for mass spectrometry (MS) and ion mobility spectrometry (IMS), and efforts continue to improve its performance. ESI-MS is most recognized for its wide application to biomacromolecules where high sensitivity is of paramount importance. However, the major limitation in sensitivity with ESI-MS is due to its low ion transmission efficiency from the ESI source into the sampling orifice and through any stages utilized for transfer of ions from atmosphere to vacuum in the MS. A series of atmospheric pressure ion focusing interfaces were designed and implemented to enhance …

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Electric Field Gradient Focusing-Uv Detection For Protein Analysis, Shu-Ling Lin Jul 2006

Electric Field Gradient Focusing-Uv Detection For Protein Analysis, Shu-Ling Lin

Theses and Dissertations

Electric field gradient focusing (EFGF) utilizes a hydrodynamic flow and an electric field gradient to focus and concentrate charged analytes and order them in a separation channel according to electrophoretic mobility. Elution can be achieved by decreasing the applied voltage or increasing the hydrodynamic flow. EFGF has the advantages of concentrating a large volume (100 micro-L) of target proteins without significant band broadening and simultaneously removing unwanted components from the sample. Two types of EFGF devices have been investigated to concentrate and separate proteins: a fiber-based EFGF device and a hydrogel-based EFGF device. Using fiber-based EFGF with UV detection, a …

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Markov Approximations: The Characterization Of Undermodeling Errors, Lei Lei Jul 2006

Markov Approximations: The Characterization Of Undermodeling Errors, Lei Lei

Theses and Dissertations

This thesis is concerned with characterizing the quality of Hidden Markov modeling when learning from limited data. It introduces a new perspective on different sources of errors to describe the impact of undermodeling. Our view is that modeling errors can be decomposed into two primary sources of errors: the approximation error and the estimation error. This thesis takes a first step towards exploring the approximation error of low order HMMs that best approximate the true system of a HMM. We introduce the notion minimality and show that best approximations of the true system with complexity greater or equal to the …

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Reinforcement Programming: A New Technique In Automatic Algorithm Development, Spencer Kesson White Jul 2006

Reinforcement Programming: A New Technique In Automatic Algorithm Development, Spencer Kesson White

Theses and Dissertations

Reinforcement programming is a new technique for using computers to automatically create algorithms. By using the principles of reinforcement learning and Q-learning, reinforcement programming learns programs based on example inputs and outputs. State representations and actions are provided. A transition function and rewards are defined. The system is trained until the system converges on a policy that can be directly implemented as a computer program. The efficiency of reinforcement programming is demonstrated by comparing a generalized in-place iterative sort learned through genetic programming to a sorting algorithm of the same type created using reinforcement programming. The sort learned by reinforcement …

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Learning A Rendezvous Task With Dynamic Joint Action Perception, Nancy Fulda, Dan A. Ventura Jul 2006

Learning A Rendezvous Task With Dynamic Joint Action Perception, Nancy Fulda, Dan A. Ventura

Faculty Publications

Groups of reinforcement learning agents interacting in a common environment often fail to learn optimal behaviors. Poor performance is particularly common in environments where agents must coordinate with each other to receive rewards and where failed coordination attempts are penalized. This paper studies the effectiveness of the Dynamic Joint Action Perception (DJAP) algorithm on a grid-world rendezvous task with this characteristic. The effects of learning rate, exploration strategy, and training time on algorithm effectiveness are discussed. An analysis of the types of tasks for which DJAP learning is appropriate is also presented.

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Preparing More Effective Liquid State Machines Using Hebbian Learning, David Norton, Dan A. Ventura Jul 2006

Preparing More Effective Liquid State Machines Using Hebbian Learning, David Norton, Dan A. Ventura

Faculty Publications

In Liquid State Machines, separation is a critical attribute of the liquid—which is traditionally not trained. The effects of using Hebbian learning in the liquid to improve separation are investigated in this paper. When presented with random input, Hebbian learning does not dramatically change separation. However, Hebbian learning does improve separation when presented with real-world speech data.

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Spatiotemporal Pattern Recognition Via Liquid State Machines, Eric Goodman, Dan A. Ventura Jul 2006

Spatiotemporal Pattern Recognition Via Liquid State Machines, Eric Goodman, Dan A. Ventura

Faculty Publications

The applicability of complex networks of spiking neurons as a general purpose machine learning technique remains open. Building on previous work using macroscopic exploration of the parameter space of an (artificial) neural microcircuit, we investigate the possibility of using a liquid state machine to solve two real-world problems: stockpile surveillance signal alignment and spoken phoneme recognition.

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Learning Quantum Operators From Quantum State Pairs, Neil Toronto, Dan A. Ventura Jul 2006

Learning Quantum Operators From Quantum State Pairs, Neil Toronto, Dan A. Ventura

Faculty Publications

Developing quantum algorithms has proven to be very difficult. In this paper, the concept of using classical machine learning techniques to derive quantum operators from examples is presented. A gradient descent algorithm for learning unitary operators from quantum state pairs is developed as a starting point to aid in developing quantum algorithms. The algorithm is used to learn the quantum Fourier transform, an underconstrained two-bit function, and Grover’s iterate.

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