Digital Commons Network^™

Ignition Mechanism In Nanocomposites Thermites, Rayon Williams

Dissertations

Nanocomposite thermites (n-thermites) have been actively investigated for a wide range of potential applications including propellants, explosives, and pyrotechnics. There have been several recent efforts aimed at understanding ignition mechanisms of nanocomposite reactive materials. Although significant progress has been made, ignition mechanisms remain elusive. At the same time, a robust ignition model is required to incorporate these materials in practical energetic formulations. A challenge of this effort is to describe the mechanisms of ignition of n-thermites prepared by Arrested Reactive Milling (ARM) with different stimuli, including heat, spark and impact and also develop a multi-step kinetic model describing different processes …

Intent-Based User Segmentation With Query Enhancement, Wei Xiong

Dissertations

With the rapid advancement of the internet, accurate prediction of user's online intent underlying their search queries has received increasing attention from the online advertising community. As a rich source of information on web user's behavior, query logs have been leveraged by advertising companies to deliver personalized advertisements. However, a typical query usually contains very few terms, which only carry a small amount of information about a user's interest. The tendency of users to use short and ambiguous queries makes it difficult to fully describe and distinguish a user's intent. In addition, the query feature space is sparse, as only …

Gaussian Beam Scattering From A Deterministic Rough Metal Surface, Qi Wang

Theses

A full-wave theory of plane wave scattering from rough surfaces called the Correction Current (CC) method was recently developed for the two-dimensional scatter problem that have a one-dimensional roughness profile. The method involves a primary field and radiation modes that are plane-wave-type fields that satisfy the boundary conditions at the rough surface. These fields do not satisfy Maxwell's source free equations, but they are forced to satisfy Maxwell's equations with distributed sources upon the introduction of fictitious volume currents distributions which correct for the field errors. Additionally, current sheet distributions are introduced which generate a radiation modal field that satisfies …

The Control Of The False Discovery Rate Under Structured Hypotheses, Gavin Lynch

Dissertations

The hypotheses in many multiple testing problems often have some inherent structure based on prior information such as Gene Ontology in gene expression data. However, few false discovery rate (FDR) controlling procedures take advantage of this inherent structure. In this dissertation, we develop FDR controlling methods which exploit the structural information of the hypotheses.

First, we study the fixed sequence structure where the testing order of the hypotheses has been pre-specified. We are motivated to study this structure since it is the most basic of structures, yet, it has been largely ignored in the literature on large scale multiple testing. …

Electro-Deformation Of A Moving Boundary: A Drop Interface And A Lipid Bilayer Membrane, Herve Nganguia

Dissertations

This dissertation focuses on the deformation of a viscous drop and a vesicle immersed in a (leaky) dielectric fluid under an electric field. A number of mathematical tools, both analytical and numerical, are developed for these investigations. The dissertation is divided into three parts. First, a large-deformation model is developed to capture the equilibrium deformation of a viscous spheroidal drop covered with non-diffusing insoluble surfactant under a uniform direct current (DC) electric field. The large- deformation model predicts the dependence of equilibrium spheroidal drop shape on the permittivity ratio, conductivity ratio, surfactant coverage, and the elasticity number. Results from the …

Data Analysis And Simulation For Warranties And Golf Handicaps, Sonia Bandha

Dissertations

In this dissertation, we discuss the application of data analysis and numerical simulation in order to gain insight into problems related to warranty cost management and the effectiveness of the golf handicap system. Despite the commonalities of the approaches, we will discuss these problems in turn.

For many moderately high value items with a substantial sales volume (such as automobiles), a warranty is used as an important element of marketing products as a better warranty typically signals higher product quality to customers. Much recent research on modeling and optimization of servicing costs for Non-Renewing Free Replacement Warranties (NR-FRW) assumes that …

Global Optimization Methods For Localization In Compressive Sensing, Marco Rossi

Dissertations

The dissertation discusses compressive sensing and its applications to localization in multiple-input multiple-output (MIMO) radars. Compressive sensing is a paradigm at the intersection between signal processing and optimization. It advocates the sensing of “sparse” signals (i.e., represented using just a few terms from a basis expansion) by using a sampling rate much lower than that required by the Nyquist-Shannon sampling theorem (i.e., twice the highest frequency present in the signal of interest). Low-rate sampling reduces implementation’s constraints and translates into cost savings due to fewer measurements required. This is particularly true in localization applications when the number of measurements is …

Fwer Controlling Procedures For Testing Multiple Hypotheses With Hierarchical Structure And Applications In Clinical Trials, Zhiying Qiu

Dissertations

In applications of clinical trials, the hypotheses to be tested often exhibit a hierarchical structure, and are usually hierarchically ordered based on their importance, clinical relevance, or dose concentration, etc. Thus, they are tested in a pre-defined fixed sequence. In some more complex cases, the hypotheses to be tested are hierarchically grouped into several families, and thus the families are tested in a sequential order. Although such problems of structured multiple testing have received much attention and several popular FWER controlling procedures, such as conventional fixed sequence procedure, fallback procedure and gatekeeping procedure have been introduced, not much progress has …

Computational Methods For The Analysis Of Next Generation Sequencing Data, Wei Wang

Dissertations

Recently, next generation sequencing (NGS) technology has emerged as a powerful approach and dramatically transformed biomedical research in an unprecedented scale. NGS is expected to replace the traditional hybridization-based microarray technology because of its affordable cost and high digital resolution. Although NGS has significantly extended the ability to study the human genome and to better understand the biology of genomes, the new technology has required profound changes to the data analysis. There is a substantial need for computational methods that allow a convenient analysis of these overwhelmingly high-throughput data sets and address an increasing number of compelling biological questions which …

Investigation Of New Feature Descriptors For Image Search And Classification, Atreyee Sinha

Dissertations

Content-based image search, classification and retrieval is an active and important research area due to its broad applications as well as the complexity of the problem. Understanding the semantics and contents of images for recognition remains one of the most difficult and prevailing problems in the machine intelligence and computer vision community. With large variations in size, pose, illumination and occlusions, image classification is a very challenging task. A good classification framework should address the key issues of discriminatory feature extraction as well as efficient and accurate classification. Towards that end, this dissertation focuses on exploring new image descriptors by …

Characterizing Motor Control Signals In The Spinal Cord, Yi Guo

Dissertations

The main goal of this project is to develop a rodent model to study the central command signals generated in the brain and spinal cord for the control of motor function in the forearms. The nature of the central command signal has been debated for many decades with only limited progress. This thesis presents a project that investigated this problem using novel techniques. Rats are instrumented to record the control signals in their spinal cord while they are performing lever press task they are trained in. A haptic interface and wireless neural data amplifier system simultaneously collects dynamic and neural …

Physical Controls On Water Flow And Solute Transport In Coastal Aquifers, Xiaolong Geng

Dissertations

Groundwater flow and associated subsurface solute fates have a significant impact on the structure and productivity of near-shore coastal ecosystems. For proper assessment and management of these coastal groundwater resources, it is quite essential to investigate the key factors (tides, waves, evaporation, and freshwater recharge etc.) affecting coastal groundwater systems. The main objective of this study is to examine and quantify two important physical control factors, oceanic waves and evaporation, on the groundwater flow and solute transport in near-shore aquifers. For the investigation of wave effects, a Computational Fluid Dynamics (CFD) modeling tool, Fluent, is used to simulate wave- induced …

Field Methods For Rapidly Characterizing Contaminant Mobility In Paint Waste During Bridge Rehabilitation, Zhan Shu

Dissertations

Currently, the New York State Department of Transportation (NYSDOT) uses a conservative approach of classifying all paint waste as hazardous from bridges undergoing rehabilitation which were constructed before 1989. This practice stems from the fact that there is no approved reliable, fast, and efficient method for classifying paint waste in-situ as non-hazardous. The main objective of this study was to develop a model that can predict the leachability of trace metals in paint waste generated during bridge rehabilitation. A statistically significant number of bridge sites were sampled based on hypothesis testing. Samples were then evaluated for total concentration of Resource …

Analysis Of Far-Infrared Optical Spectra Of Multiferroics, Eric C. Standard

Dissertations

The optical spectra of multiferroic crystals Dy₃Fe₅O₁₂, Tb₃Fe₅O₁₂, and four hexagonal RMnO₃ (5D= Er, Tm, Yb, Lu) are studied using intense bright synchrotonic light in the infrared spectral range. In regards to the materials analyzed, two rare earth iron garnets and four rare earth manganites in total are examined. These materials have attracted much attention due to their interesting magnetoelectric properties. They could serve as the basis for the next generation of faster and more energy efficient memory and logic devices. To examine these materials, two …

Nanocarbon Immobilized Membrane For Separation And Analysis, Madhuleena Bhadra

Dissertations

Membrane processes classically cover a wide range of applications associated with various aspects of separation and purification. Over the last few years, membrane based processes have received much interest due to their compact and modular architecture, low energy consumption and cost effective separation. With the development of diverse nanomaterials which can serve as nanosorbents, or provide specific morphology for selective solute transport, recent years have witnessed the emergence of nanocarbon based membranes that can address some of the limitations of conventional membrane processes and make feasible the next generation of breakthroughs.

The objective of this research is the exploration of …

Inverse Methods For Sound Speed Estimation In The Ocean, Tao Lin

Dissertations

This dissertation presents theoretical and computational approaches for estimating sound-speed in the ocean under different conditions. The first part of the dissertation discusses a fast approach for solving the inverse problem of estimating sediment sound-speed based on the Deift-Trubowitz trace formula. Under certain assumptions, this algorithm can recover the sound speed profile in the seabed using pressure field measurements in the water column at low frequencies. The inversion algorithm requires solving a non-linear integral equation. In the past, Stickler and Zhou employed a first order Born approximation for solving the integral equation. This work introduces two new methods. The first …

Modeling, Control And Simulation Of Control-Affine Nonlinear Systems With State-Dependent Transfer Functions, Roger Kobla Kwadzogah

Dissertations

There has been no known research that applies nonlinear transfer function to a nonlinear control problem. The belief is that nonlinear systems have no transfer functions. The Laplace transformation required to define transfer functions is not tractable mathematically when the coefficients of the differential equation are functions of state, output and control variables. In other words, it is not defined for systems that do not obey principles of superposition. Only linear systems obey this principle. Therefore, this dissertation work represents the very first research to demonstrate how transfer functions can be used to represent and design feedback control for nonlinear …

Dynamics Of 1d Granular Column, Luo Zuo

Dissertations

This dissertation is focused on a discrete element study of the dynamics of a one- dimensional column of inelastic spheres that it subjected to taps by prescribing a half sine wave pulse to supporting floor. Contact interactions obey the Walton-Braun soft-sphere model in which the loading (unloading) path is governing by linear springs of stiffness K1, thereby producing col lisional energy loss through a constant restitution coefficient e. Over a ‘short time scale’, computations are done to examine the floor pulse wave as it propagates through the column contact network. Comparisons of the simulated findings are made with experimental measurements …

Hydrodynamic Cfd Modeling Of A Pharmaceutical Reactor Vessel Provided With A Retreat-Blade Impeller Under Different Baffling Conditions, Christopher G. Foehner

Theses

In the pharmaceutical industry, glass-lined reactors and vessels are often utilized to carry out a variety of different unit operations. Within these systems, both the vessel and impellers are typically glass-lined in order to provide superior corrosion resistance, prevent product contamination, and enhance cleanability. This approach, in turn, often requires the use of different, and sometimes sub-optimal, baffling conditions, which affect the hydrodynamics of the vessels and the reactor performance.

Computational Fluid Dynamics (CFD) is a computational tool that employs numerical methods and algorithms to discretize and numerically solve partial differential equations (PDEs) representing mass, energy, and momentum conservation equations …

Risk Prediction With Genomic Data, Bharati Jadhav

Theses

Genome wide association study (GWAS) is widely used with various machine learning algorithms to predict disease risk. This thesis investigates this widely used approach of GWAS using Single Nucleotide Polymorphism (SNP) genotype data and a novel approach of disease risk prediction with whole exome sequencing data, namely Whole Exome Wide Association Study (WEWAS). It further applies a discriminating machine learning algorithm, namely a Support Vector Machine (SVM) with different Kernel functions. For this study, only SNPs generated using genotyping technology, which focuses more on common variants, are used initially for disease prediction. Later, the whole exome data generated using Next …

Evaluation Of Methods To Account For Release From Nanofiber Scaffolds, Jennifer Moy

Theses

Electrospinning is a common technique utilized to form fibers from the micro- to nanometer range. Nanofibers form through electrospinning can be utilized as scaffolds since the fiber structures are similar to the structures within the extracellular matrix. Researchers use additives, such as growth factors, to help facilitate cell proliferation and function. Also, researchers are attempting to use electrospun fibers for drug delivery and as wound dressings since the electrospun fibers have high surface area to volume ratio. In both situations, the release of either the additive or the drug needs to be controlled so that the fibers would release the …

Optimization Of Vehicle Routing And Scheduling With Travel Time Variability - Application In Winter Road Maintenance, Haifeng Yu

Dissertations

This study developed a mathematical model for optimizing vehicle routing and scheduling, which can be used to collect travel time information, and also to perform winter road maintenance operations (e.g., salting, plowing). The objective of this research was to minimize the total vehicle travel time to complete a given set of service tasks, subject to resource constraints (e.g., truck capacity, fleet size) and operational constraints (e.g., service time windows, service time limit).

The nature of the problem is to design vehicle routes and schedules to perform the required service on predetermined road segments, which can be interpreted as an arc …

Dynamics Of Phase Locking In Neuronal Networks In The Presence Of Synaptic Plasticity, Zeynep Akcay

Dissertations

The behavior generated by neuronal networks depends on the phase relationships of its individual neurons. Observed phases result from the combined effects of individual cells and synaptic connections whose properties change dynamically. The properties of individual cells and synapses can often be characterized by driving the cell or synapse with inputs that arrive at different phases or frequencies, thus producing a feed-forward description of these properties. In this study, a recurrent network of two oscillatory neurons that are coupled with reciprocal synapses is considered. Feed-forward descriptions of the phase response curves of the neurons and the short-term synaptic plasticity properties …

The Effect Of Mechanical Vestibular Stimulation On Muscle Tone And Spasticity In Individuals With Neurological Impairment, Ghaith J. Androwis

Dissertations

In the desire to better understand spasticity mainly in Cerebral Palsy (CP) and to examine vestibular stimulation as a future intervention for .muscle tone reduction, and to be able to describe the change in level of spasticity in subjects with disability and describe interventions effects, a series of experiments are done on children with spasticity. In addition to understanding the otoliths in the vestibular system and their projections, properties and pathways a more important major objective of this work is to validate the changes in otoliths signal caused by vestibular stimulation based on the Equilibrium Point Hypothesis and the inclusion …

Analyses Of Groundwater Contribution To A Riverine Wetland, Farzad Mahmoodinobar

Dissertations

Rainfall, runoff, overbank flow and groundwater, all contribute water to wetlands. Each transport element is associated with unique modeling approaches and uncertainties. Transpiration is perhaps the hardest to quantify as it is subject to all the variability of plant growth. Transpiration causes land area to lose moisture and the loss amount depends on precipitation incidence, the temperature and type and extent of vegetation. Plants can intercept virtually all recharge during the growing season and almost none from late fall to early spring in northeastern United States. Thus, an improvement in the transpiration element can contribute considerably to an improved groundwater …

Nanocarbons As Charge Carriers In Organic Solar Cells, Xinbo C. Lau

Dissertations

Organic photovoltaics (OPV) are an alternate to conventional silicon and thin film solar cells. They have several advantages such as simple fabrication, low material cost, light weight, and the ability to cover large areas. Typical OPV are based on bulk heterojunction structure consisting of a blend of an electron-donating semiconductor polymer and an electron-accepting molecule. Various approaches have been pursued to improve the performance of OPV: low bandgap polymers, new electron acceptors, processing additives, and tandem cell architecture.

Nanocarbons possess unique physical and chemical properties that can contribute to the enhancement of OPV performance, such as charge carrier mobility, thermal …

Increasing Adolescent Interest In Computing Through The Use Of Social Cognitive Career Theory, Osama Eljabiri

Dissertations

While empirical research efforts are sufficient to provide evidence of the role of most constructs in the Social Cognitive Career Theory (SCCT), this dissertation shifts the research focus and finds serious shortcomings in defining the construct of computer technology learning experiences design.

The purpose of this dissertation is to investigate whether, and to what extent, the proposed SCCT-enhanced framework can increase self-efficacy and interest of pre-college and college students in computer-based technology through the newly proposed “Learning Experiences” construct; in particular, whether it can reduce the gender gaps.

As a result of a comprehensive literature review, the dissertation connects learning, …

Innovative Local Texture Descriptors With Application To Eye Detection, Jiayu Gu

Dissertations

Local Binary Patterns (LBP), which is one of the well-known texture descriptors, has broad applications in pattern recognition and computer vision. The attractive properties of LBP are its tolerance to illumination variations and its computational simplicity. However, LBP only compares a pixel with those in its own neighborhood and encodes little information about the relationship of the local texture with the features. This dissertation introduces a new Feature Local Binary Patterns (FLBP) texture descriptor that can compare a pixel with those in its own neighborhood as well as in other neighborhoods and encodes the information of both local texture and …

Extracting Product Development Intelligence From Web Reviews, Ismail Artun Yagci

Dissertations

Product development managers are constantly challenged to learn what the consumer product experience really is, and to learn specifically how the product is performing in the field. Traditionally, they have utilized methods such as prototype testing, customer quality monitoring instruments, field testing methods with sample customers, and independent assessment companies. These methods are limited in that (i) the number of customer evaluations is small, and (ii) the methods are driven by a restrictive structured format. Today the web has created a new source of product intelligence; these are unsolicited reviews from actual product users that are posted across hundreds of …

A Modeling Study Of The History-Dependence Of Conduction Delay In Unmyelinated Axons, Yang Zhang

Dissertations

Conduction delay in an axon is the time required for an action potential to propagate between two positions. It is a function of the axon’s passive membrane properties, voltage-gated ion channels and the Na+/K+ pump, and can be substantially affected by neuromodulators. The conduction delay of action potential, generated by the pyloric dilator (PD) neuron unmyel i nated motor axon in the stomatogastric nervous system, shows significant variability with ongoing bursting or Poisson stimulation. When the axon is stimulated, the mean value (Dmean) and coefficient variation of conduction delay (CV-D) slowly increase with time (slow timescale effect), and the relationship …