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Articles 1351 - 1380 of 2906

Full-Text Articles in Physical Sciences and Mathematics

Integral Traces Of Weak Maass Forms Of Genus Zero Odd Prime Level, Nathan Eric Green Jul 2013

Integral Traces Of Weak Maass Forms Of Genus Zero Odd Prime Level, Nathan Eric Green

Theses and Dissertations

Duke and Jenkins defined a family of linear maps from spaces of weakly holomorphic modular forms of negative integral weight and level 1 into spaces of weakly holomorphic modular forms of half integral weight and level 4 and showed that these lifts preserve the integrality of Fourier coefficients. We show that the generalization of these lifts to modular forms of genus 0 odd prime level also preserves the integrality of Fourier coefficients.

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Spectral Stability Of Weak Detonations In The Majda Model, Jeffrey James Hendricks Jul 2013

Spectral Stability Of Weak Detonations In The Majda Model, Jeffrey James Hendricks

Theses and Dissertations

Using analytical and numerical Evans-function techniques, we examine the spectral stability of weak-detonation-wave solutions of Majda's scalar model for a reacting gas mixture. We provide a proof of monotonicity of solutions. Using monotonicity we obtain a bound on possible unstable eigenvalues for weak-detonation-wave solutions that improves on the more general bound given by Humpherys, Lyng, and Zumbrun. We use a numerical approximation of the Evans function to search for possible unstable eigenvalues in the bounded region obtained by the energy estimate. For the parameter values tested, our results combined with the result of Lyng, Raoofi, Texier, and Zumbrun demonstrate that …

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Market Dynamics With Non-Homogeneous Poisson Processes, Preston T. Redd Jun 2013

Market Dynamics With Non-Homogeneous Poisson Processes, Preston T. Redd

Theses and Dissertations

The Bertrand Duopoly model for demand in economics is a well-used model. Although this model has important insights towards pricing strategy, it does not accurately depict true market behaviors. In this paper, we will examine the advantages and disadvantages of the current model and its assumptions.We then take a whole new approach towards modeling this phenomena, using Poisson processes to model the demand of goods. We will discuss why this is a better approach and explain how we can extend this to better understand pricing strategies and market dynamics. We then apply our findings to the newsvendor problem, a commonly …

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Investigation Of Water-Molecule Complexes And Their Catalytic Effect On Important Atmospheric Reactions, Taylor Scott Cline Jun 2013

Investigation Of Water-Molecule Complexes And Their Catalytic Effect On Important Atmospheric Reactions, Taylor Scott Cline

Theses and Dissertations

This dissertation is a collection of works that investigates issues related to environmental chemistry. The first portion of this research explores the role of water vapor on the kinetics of important atmospheric reactions. Work is presented on the self-reaction of β-hydroxyethyl peroxy radical (β-HEP) and the catalytic increase in reaction rate by water vapor. β-HEP serves as a model system for investigating the possible role of water vapor in perturbing the kinetics and product branching ratio of atmospheric reactions of other alkyl peroxy radicals. The self-reaction rate coefficient of β-HEP was investigated between 276-296 K with 1.0 × 10^15 to …

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The Frobenius Manifold Structure Of The Landau-Ginzburg A-Model For Sums Of An And Dn Singularities, Rachel Megan Webb Jun 2013

The Frobenius Manifold Structure Of The Landau-Ginzburg A-Model For Sums Of An And Dn Singularities, Rachel Megan Webb

Theses and Dissertations

In this thesis we compute the Frobenius manifold of the Landau-Ginzburg A-model (FJRW theory) for certain polynomials. Specifically, our computations apply to polynomials that are sums of An and Dn singularities, paired with the corresponding maximal symmetry group. In particular this computation applies to several K3 surfaces. We compute the necessary correlators using reconstruction, the concavity axiom, and new techniques. We also compute the Frobenius manifold of the D3 singularity.

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Inverted Sequence Identification In Diploid Genomic Scaffold Assembly Via Weighted Max-Cut Reduction, Paul Mark Bodily Jun 2013

Inverted Sequence Identification In Diploid Genomic Scaffold Assembly Via Weighted Max-Cut Reduction, Paul Mark Bodily

Theses and Dissertations

Virtually all genome assemblers to date are designed for use with data from haploid or homozygous diploid genomes. Their use on heterozygous genomic datasets generally results in highly-fragmented, error-prone assemblies, owing to the violation of assumptions during both the contigging and scaffolding phases. Of the two phases, scaffolding is more particularly impacted and algorithms to facilitate the scaffolding of heterozygous data are lacking. We present a stand-alone scaffolding algorithm, ScaffoldScaffolder, designed specifically for scaffolding diploid genomes. A fundamental step in the scaffolding phase is the assignment of sequence orientations to contigs within scaffolds. Deciding such an assignment in the presence …

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Patchmatch-Based Content Completion Of 3d Images, Joel Arthur Howard Jun 2013

Patchmatch-Based Content Completion Of 3d Images, Joel Arthur Howard

Theses and Dissertations

This thesis presents a method for completing target regions ("hole filling") in RGB stereo pairs. It builds upon the state of the art for completing single images by matching to and then blending source patches drawn from the rest of the image. A method is introduced for first completing the respective disparity maps using a coupled partial differential equation based on that of Bertalmio, et al. extended to create mutual disparity consistency. Estimated disparities are then used to guide completion of the missing color image texture. An extension to the coherence-based objective function introduced by Wexler, et al. is then …

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Exploration Of The Low-Molecular Weight Proteome Of Tissue And Serum, With Applications To Disease Biomarker Discovery, Meihwa Tanielle Alvarez Jun 2013

Exploration Of The Low-Molecular Weight Proteome Of Tissue And Serum, With Applications To Disease Biomarker Discovery, Meihwa Tanielle Alvarez

Theses and Dissertations

The low-molecular weight proteome is of great interest due to the vast number of smaller proteins and peptides present within it, some of which are likely to be disease-related and may provide insights into disease mechanisms or even prediction and diagnosis. Serum is often the most preferred specimen for disease prediction or diagnosis, as it can be obtained less-invasively and its collection is fairly routine in a clinical setting. Although serum samples are one of the most preferred specimens for disease studies, additional disease information may also be obtained using other specimens, such as tissue. The study of tissue specimens …

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Interactive Depth-Aware Effects For Stereo Image Editing, Joshua E. Abbott Jun 2013

Interactive Depth-Aware Effects For Stereo Image Editing, Joshua E. Abbott

Theses and Dissertations

This thesis introduces methods for adding user-guided depth-aware effects to images captured with a consumer-grade stereo camera with minimal user interaction. In particular, we present methods for highlighted depth-of-field, haze, depth-of-field, and image relighting. Unlike many prior methods for adding such effects, we do not assume prior scene models or require extensive user guidance to create such models, nor do we assume multiple input images. We also do not require specialized camera rigs or other equipment such as light-field camera arrays, active lighting, etc. Instead, we use only an easily portable and affordable consumer-grade stereo camera. The depth is calculated …

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Modelling Infertility With Markov Chains, Rebecca Dorff Jun 2013

Modelling Infertility With Markov Chains, Rebecca Dorff

Theses and Dissertations

Infertility affects approximately 15% of couples. Testing and interventions are costly, in time, money, and emotional energy. This paper will discuss using Markov decision and multi-armed bandit processes to identify a systematic approach of interventions that will lead to the desired baby while minimizing costs.

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Computational Techniques For Public Health Surveillance, Scott H. Burton Jun 2013

Computational Techniques For Public Health Surveillance, Scott H. Burton

Theses and Dissertations

Public health surveillance is a critical part of understanding, and ultimately influencing, health behaviors. Traditional methods, such as questionnaires and focus groups have significant limitations including cost, delay, and size. Online social media data has the potential to overcome many of the challenges of traditional methods, but its exploitation is not trivial. We develop and apply computational techniques to enable public health surveillance in novel ways and on a larger scale than currently performed.In this regard, we present techniques for mining the who, what, and where of public health surveillance in social media. We show how computational methods can identify …

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Investment-Consumption With A Randomly Terminating Income, James Benjamin Taylor Jr. Jun 2013

Investment-Consumption With A Randomly Terminating Income, James Benjamin Taylor Jr.

Theses and Dissertations

We develop a stochastic control model for an investor's optimal investment and consumption over an uncertain planning horizon when the investor is endowed with a defaultable income stream. The distributions of the random time of default and the random terminal time are prescribed by deterministic hazard rates, and the investor makes investments in a standard financial market with a bond and a stock, modeled by geometric Brownian motion. In addition, the investor purchases insurance against both default and the terminal date, the default insurance serving as a proxy for the investor's disutility for default. We approximate the original continuous-time problem …

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Miniaturized Electrostatic Ion Beam Trap Mass Analyzer, Junting Wang Jun 2013

Miniaturized Electrostatic Ion Beam Trap Mass Analyzer, Junting Wang

Theses and Dissertations

The electrostatic ion beam trap (EIBT) was designed by D. Zajfman during the previous decade. This ion trap combines many properties of the Fourier-transform ion cyclotron resonance (FTICR) mass analyzer and time-of-flight (TOF) mass analyzer. There are several advantages for the electrostatic ion beam trap. First, large mass-to-charge particles in an electrostatic field could be easier to analyze. Second, there is a folded flight path, which could make the mass analyzer smaller compared to conventional TOF mass analyzer. This principle of operation of this ion trap is analogous to an optical resonator. The ions are trapped in a voltage valley …

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Simulation Of 810 Nm Light Propagation Through The Human Finger For Non-Invasive Blood Analysis, Nichole Millward Maughan Jun 2013

Simulation Of 810 Nm Light Propagation Through The Human Finger For Non-Invasive Blood Analysis, Nichole Millward Maughan

Theses and Dissertations

Non-invasive blood analysis devices that can measure characteristics less prominent than the oxygenation of hemoglobin are of interest in the medical community. An important step in creating these devices is to model the interaction of photons with human tissue in increasingly greater physiological detail. We have modeled, using a Monte Carlo technique, the interaction of photons through epidermis, blood and water arranged both in layers and in a homogeneous mixture. We confirm the expected linear relation between photon attenuation and material volumetric percentage in our two-layer models. We discovered that this relationship becomes non-linear in the homogeneously mixed models where …

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Identification And Differentiation Of Tier 1 Bacterial Agents Using Gas Chromatography-Mass Spectrometry, Dan Li Jun 2013

Identification And Differentiation Of Tier 1 Bacterial Agents Using Gas Chromatography-Mass Spectrometry, Dan Li

Theses and Dissertations

A simple method was developed for detection and differentiation of five Tier 1 bacterial agents, including Bacillus anthracis, Francisella tularensis, Yersinia pestis, Burkholderia pseudomallei and Burkholderia mallei as well as their closely related near neighbors by gas chromatography-mass spectrometry (GC-MS). Generally, different classes of compounds can be used as biomarkers for biowarfare agent detection, including nucleic acids (i.e., DNA or RNA), proteins (i.e., antibodies), carbohydrates (i.e., sugars), lipopolysaccharides, lipids (i.e., fatty acids) and small molecules. One-step thermochemolysis (TCM) was developed to provide GC-MS detectable biomarker signatures, including sugars, fatty acids and small molecules. Solid phase micro-extraction (SPME) was used for …

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Poincaré Polynomial Of Fjrw Rings And The Group-Weights Conjecture, Julian Boon Kai Tay Jun 2013

Poincaré Polynomial Of Fjrw Rings And The Group-Weights Conjecture, Julian Boon Kai Tay

Theses and Dissertations

FJRW-theory is a recent advancement in singularity theory arising from physics. The FJRW-theory is a graded vector space constructed from a quasihomogeneous weighted polynomial and symmetry group, but it has been conjectured that the theory only depends on the weights of the polynomial and the group. In this thesis, I prove this conjecture using Poincaré polynomials and Koszul complexes. By constructing the Koszul complex of the state space, we have found an expression for the Poincaré polynomial of the state space for a given polynomial and associated group. This Poincaré polynomial is defined over the representation ring of a group …

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Bacterial Spores Remain Viable After Electrospray Charging And Desolvation, Sara Nielson Pratt Jun 2013

Bacterial Spores Remain Viable After Electrospray Charging And Desolvation, Sara Nielson Pratt

Theses and Dissertations

The electrospray survivability of B. subtilis spores and E. coli was tested in atmospheric mobility experiments. E. coli did not survive electrospray charging and desolvation, but B. subtilis did. Experimental conditions ensured that any surviving bacteria were charged, desolvated, and de-agglomerated. B. subtilis was also found to survive both positive and negative electrospray and subsequent introduction into vacuum conditions. Attempts were made to measure the charge distribution of viable B. subtilis spores using electrostatic deflection. From those experiments, it was found that either the spores do not become highly charged under the electrospray conditions used or only spores in a …

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American Spread Option Models And Valuation, Yu Hu May 2013

American Spread Option Models And Valuation, Yu Hu

Theses and Dissertations

Spread options are derivative securities, which are written on the difference between the values of two underlying market variables. They are very important tools to hedge the correlation risk. American style spread options allow the holder to exercise the option at any time up to and including maturity. Although they are widely used to hedge and speculate in financial market, the valuation of the American spread option is very challenging. Because even under the classic assumptions that the underlying assets follow the log-normal distribution, the resulting spread doesn't have a distribution with a simple closed formula. In this dissertation, we …

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Exploring Connections Between A Very Large Volume Ignimbrite And An Intracaldera Pluton: Intrusions Related To The Oligocene Wah Wah Springs Tuff, Western Us, Chloe Noelle Skidmore May 2013

Exploring Connections Between A Very Large Volume Ignimbrite And An Intracaldera Pluton: Intrusions Related To The Oligocene Wah Wah Springs Tuff, Western Us, Chloe Noelle Skidmore

Theses and Dissertations

The Wah Wah Springs Tuff and the Wah Wah Springs Intrusive Granodiorite Porphyry(Wah Wah Springs Intrusion) both originated from the Indian Peak caldera complex, which wasa major focus of explosive silicic activity in the middle Cenozoic Great Basin ignimbrite flareup. This caldera formed 30.0 Ma when an estimated 5,900 km3 of crystal-rich dacitic magma erupted to create the Wah Wah Springs Tuff. The Wah Wah Springs Intrusion later intruded the tuff, causing resurgence of the caldera. Field, modal, and geochemical evidence suggest the tuff and intrusion are cogenetic. The mineral assemblages of the two rocks are similar: both include similar …

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Isolation, Characterization And Synthesis Of Asthma Inducing Fungal Glycolipid And Analytical Method Development For Novel Antimicrobial Peptide Mimics, Vinod Chaudhary May 2013

Isolation, Characterization And Synthesis Of Asthma Inducing Fungal Glycolipid And Analytical Method Development For Novel Antimicrobial Peptide Mimics, Vinod Chaudhary

Theses and Dissertations

NKT cells are an important part of human immune system and recognize a specific set of antigens called glycolipids. Only a handful of "natural" NKT cell antigens are known till date. Although NKT cells play a protective role against pathogenic organisms, imbalances in NKT cell functions are implicated in many diseases including asthma. Allergic asthma, a Th2 driven inflammation of airways, is primarily caused by inhalation of environmental allergens. In the last decade, inhaled allergen Aspergillus fumigatus has been under scrutiny for the presence of NKT cell antigens that might trigger asthma. We successfully isolated, characterized and synthesized a "natural" …

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Synthesis And Immunological Evaluation Of Type I, Type Ii, And Gamma Delta Nkt Cell Antigens, Brian L. Anderson May 2013

Synthesis And Immunological Evaluation Of Type I, Type Ii, And Gamma Delta Nkt Cell Antigens, Brian L. Anderson

Theses and Dissertations

The purpose of the immune system is to protect our bodies from infection. One way it accomplishes this task is through the presentation of foreign pathogens to NKT cells. After an antigen is presented to the T cell receptor, activated NKT cells quickly release soluble chemical signals, termed chemokines and cytokines, that modulate the response of the immune system. Due to the immunological relevance of NKT cell activation, we developed and synthesised non-natural analogs of immunostimulatory type I, II, and gamma delta NKT cell antigens. The immunological evaluations of these analogs resulted in identification of sulfatide as a gamma delta …

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Message Protector: Demonstrating That Manual Encryption Improves Usability, Nathan I. Kim May 2013

Message Protector: Demonstrating That Manual Encryption Improves Usability, Nathan I. Kim

Theses and Dissertations

Billions of people currently use the Internet. Many Internet users share sensitive information through online services. Several secure data sharing tools have been developed to protect this sensitive information. A common practice in the design of usable security is to provide automatic data encryption that is transparent to users. We hypothesize that automatic encryption can decrease usability and comprehensibility, increasing the likelihood that users will unknowingly disclose sensitive information. This thesis presents Message Protector (MP), a novel Internet secure data sharing tool design that through manual encryption, purposely exposes technical details in a usable manner to increase usability and reduce …

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Cluster Expansion Models Via Bayesian Compressive Sensing, Lance Jacob Nelson May 2013

Cluster Expansion Models Via Bayesian Compressive Sensing, Lance Jacob Nelson

Theses and Dissertations

The steady march of new technology depends crucially on our ability to discover and design new, advanced materials. Partially due to increases in computing power, computational methods are now having an increased role in this discovery process. Advances in this area speed the discovery and development of advanced materials by guiding experimental work down fruitful paths. Density functional theory (DFT)has proven to be a highly accurate tool for computing material properties. However, due to its computational cost and complexity, DFT is unsuited to performing exhaustive searches over many candidate materials or for extracting thermodynamic information. To perform these types of …

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Improving Crowd Simulation With Optimal Acceleration Angles, Movement On 3d Surfaces, And Social Dynamics, Brian C. Ricks Apr 2013

Improving Crowd Simulation With Optimal Acceleration Angles, Movement On 3d Surfaces, And Social Dynamics, Brian C. Ricks

Theses and Dissertations

Crowd simulation plays a critical role in modern films, games, and architectural design. However, despite decades of algorithmic improvements, crowds use sub-optimal heuristics, are primarily constrained to 2D surfaces, and show few if any social dynamics. This dissertation proposes that a solution to these problems lies in altering how each agent perceives its environment as opposed to new obstacle avoidance algorithms. First, this dissertation presents a theoretical look at optimal agent movement. Next, in order to place crowds on arbitrary 3D manifolds, algorithms are proposed that change how each agent perceives its environment. The resulting crowds move naturally across a …

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Prevalence Of Reflexivity And Its Impact On Success In Open Source Software Development: An Empirical Study, Brandon D. Foushee Apr 2013

Prevalence Of Reflexivity And Its Impact On Success In Open Source Software Development: An Empirical Study, Brandon D. Foushee

Theses and Dissertations

Conventional wisdom, inspired in part by Eric Raymond, suggests that open source developers primarily develop software for developers like themselves. In our studies we distinguish between reflexive software (software written primarily for other developers) and irreflexive software (software written primarily for passive users). In the first study, we present four criteria which we then use to assess project reflexivity in SourceForge. These criteria are based on three specific indicators: intended audience, relevant topics, and supported operating systems. Based on our criteria, we find that 68% of SourceForge projects are reflexive (in the sense described by Raymond). In the second study, …

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Probabilistic Explicit Topic Modeling, Joshua Aaron Hansen Apr 2013

Probabilistic Explicit Topic Modeling, Joshua Aaron Hansen

Theses and Dissertations

Latent Dirichlet Allocation (LDA) is widely used for automatic discovery of latent topics in document corpora. However, output from analysis using an LDA topic model suffers from a lack of identifiability between topics not only across corpora, but across runs of the algorithm. The output is also isolated from enriching information from knowledge sources such as Wikipedia and is difficult for humans to interpret due to a lack of meaningful topic labels. This thesis introduces two methods for probabilistic explicit topic modeling that address these issues: Latent Dirichlet Allocation with Static Topic-Word Distributions (LDA-STWD), and Explicit Dirichlet Allocation (EDA). LDA-STWD …

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Kinetics Of Atmospheric Reactions Of Biogenic Volatile Organic Compounds: Measurement Of The Rate Constant Ofthujone + Cl· At 296 K And Calculation Ofthe Equilibrium Constant For The Ho2ch2ch2o2· H2o Complex, Marie Coy Killian Apr 2013

Kinetics Of Atmospheric Reactions Of Biogenic Volatile Organic Compounds: Measurement Of The Rate Constant Ofthujone + Cl· At 296 K And Calculation Ofthe Equilibrium Constant For The Ho2ch2ch2o2· H2o Complex, Marie Coy Killian

Theses and Dissertations

Biogenic volatile organic compounds (VOCs) react with Cl and OH radicals and the resulting radicals combine with oxygen to form peroxy radicals RO2. Organic peroxy radicals can then react with NO to form NO2, a precursor of tropospheric ozone. The work presented here explored the initial reaction between Cl and thujone, a VOC emitted by Great Basin sagebrush. The rate constant for the reaction of thujone + Cl at 296 K was measured with the method of relative rates with FTIR for detection of reactants. LEDs were used to photolyze Cl2 to generate Cl in the reaction cell. Thujone was …

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Facies And Reservoir Characterization Of The Permian White Rim Sandstone, Black Box Dolomite, And Black Dragon Member Of The Triassic Moenkopi Formation For Co2 Storage And Sequestration At Woodside Field, East-Central Utah, Walter Andrew Harston Apr 2013

Facies And Reservoir Characterization Of The Permian White Rim Sandstone, Black Box Dolomite, And Black Dragon Member Of The Triassic Moenkopi Formation For Co2 Storage And Sequestration At Woodside Field, East-Central Utah, Walter Andrew Harston

Theses and Dissertations

Geologic sequestration of anthropogenic carbon dioxide (CO2) greenhouse gas emissions is an engineering solution that potentially reduces CO2 emissions released into the atmosphere thereby limiting their effect on climate change. This study focuses on Woodside field as a potential storage and sequestration site for CO2 emissions. The Woodside field is positioned on a doubly plunging, asymmetrical anticline on the northeast flank of the San Rafael Swell. Particular focus will be placed on the Permian White Rim Sandstone, Black Box Dolomite and Black Dragon Member of the Triassic Moenkopi Formation as the reservoir/seal system to store and sequester CO2 at Woodside …

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Probability Of Belonging To A Language, Kevin Michael Brooks Cook Apr 2013

Probability Of Belonging To A Language, Kevin Michael Brooks Cook

Theses and Dissertations

Conventional language models estimate the probability that a word sequence within a chosen language will occur. By contrast, the purpose of our work is to estimate the probability that the word sequence belongs to the chosen language. The language of interest in our research is comprehensible well-formed English. We explain how conventional language models assume what we refer to as a degree of generalization, the extent to which a model generalizes from a given sequence. We explain why such an assumption may hinder estimation of the probability that a sequence belongs. We show that the probability that a word sequence …

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Warping-Based Approach To Offline Handwriting Recognition, Douglas J. Kennard Apr 2013

Warping-Based Approach To Offline Handwriting Recognition, Douglas J. Kennard

Theses and Dissertations

An enormous amount of the historical record is currently trapped in non-indexed handwritten format. Even after being scanned into images, only a minute fraction of the existing records can be manually transcribed / indexed with reasonable amounts of time and cost. Although progress continues to be made with automatic handwriting recognition (HR), it is not yet good enough to replace manual transcription or indexing. Much of the recent HR work has focused on incremental improvements to methods based on Hidden Markov Models (HMMs) and other similar probabilistic approaches. In this dissertation we present a fundamentally new approach to HR based …

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