Digital Commons Network^™

Image Quality Modeling And Characterization Of Nyquist Sampled Framing Systems With Operational Considerations For Remote Sensing, Rey Jan D. Garma

Theses

The trade between detector and optics performance is often conveyed through the Q metric, which is defined as the ratio of detector sampling frequency and optical cutoff frequency. Historically sensors have operated at Q~1, which introduces aliasing but increases the system modulation transfer function (MTF) and signal-to-noise ratio (SNR). Though mathematically suboptimal, such designs have been operationally ideal when considering system parameters such as pointing stability and detector performance. Substantial advances in read noise and quantum efficiency of modern detectors may compensate for the negative aspects associated with balancing detector/optics performance, presenting an opportunity to revisit the potential for implementing …

Hybrid Statistical Data Mining Framework For Multi-Commodity Fixed Charge Network Flow Problem, Anurag A. Ladage

Theses

This paper presents a new approach to analyze the network structure in multi-commodity fixed charge network flow problems (MCFCNF). This methodology uses historical data produced from repeatedly solving the traditional MCFCNF mathematical model as input for the machine-learning framework. Further, we reshape the problem as a binary classification problem and employ machine-learning algorithms to predict network structure. This predicted network structure is further used as an initial solution for our mathematical model. The quality of the initial solution generated is judged on the basis of predictive accuracy, feasibility and reduction in solving time.

Factors Influencing Asiatic Oak Weevil Interactions With Native Ecosystem Engineers Over Time, Daniel Rothschild O'Brien

Theses

I sought to build a model to predict current and future abundance of Asiatic oak weevil (Coleoptera: Curculionidae: Cyrtepistomus castaneus) by using the relative abundance of leaf tying and leaf rolling caterpillars. The Asiatic oak weevil is an exotic species that has been observed inside leaf ties and leaf rolls made by native Lepidoptera caterpillars. Chapter one is a review of the known relationships between animal constructs and exotic species. Within this review I transition from natural structures, to animal architects, and to ecosystem engineers and how they have a population dynamic impact on the invasive species. I also discuss …

Performance Evaluation Of Iii-V Hetero/Homojunction Esaki Tunnel Diodes On Si And Lattice Matched Substrates, Paul M. Thomas

Theses

Understanding of quantum tunneling phenomenon in semiconductor systems is increasingly important as CMOS replacement technologies are investigated. This work studies a variety of heterojunction materials and types to increase tunnel currents to CMOS competitive levels and to understand how integration onto Si substrates affects performance. Esaki tunnel diodes were grown by Molecular Beam Epitaxy (MBE) on Si substrates via a graded buffer and control Esaki tunnel diodes grown on lattice matched substrates for this work. Peak current density for each diode is extracted and benchmarked to build an empirical data set for predicting diode performance. Additionally, statistics are used as …

Design And Analysis Of A Reconfigurable Hierarchical Temporal Memory Architecture, Abdullah M. Zyarah

Theses

Self-learning hardware systems, with high-degree of plasticity, are critical in performing spatio-temporal tasks in next-generation computing systems. To this end, hierarchical temporal memory (HTM) offers time-based online-learning algorithms that store and recall temporal and spatial patterns. In this work, a reconfigurable and scalable HTM architecture is designed with unique pooling realizations. Virtual synapse design is proposed to address the dynamic interconnections occurring in the learning process. The architecture is interweaved with parallel cells and columns that enable high processing speed for the cortical learning algorithm.

HTM has two core operations, spatial and temporal pooling. These operations are verified for two …

Characterization Of Cardiac Electrogram Signals During Atrial Fibrillation, Prasanth Ganesan

Theses

Atrial fibrillation (AF) is the most common cardiac arrhythmia in United States. The most popular treatment for AF is a percutaneous procedure called catheter ablation. Current AF ablation procedures unfortunately have a poor success rate, primarily because the mechanisms involved in AF are incompletely understood even today. Intra-atrial electrograms have previously been shown to provide information on the mechanisms of AF. This thesis focuses on two such mechanisms – AF-sustaining sites known as sustained rotational activities (RotAs), and atrial tissue with unique electrical properties known as myocardial scars. Catheter ablation procedures today construct the 3D electroanatomic map of the left …

Power Analysis Attacks On Keccak, Xuan D. Tran

Theses

Side Channel Attacks (SCA) exploit weaknesses in implementations of cryptographic functions resulting from unintended inputs and outputs such as operation timing, electromagnetic radiation, thermal/acoustic emanations, and power consumption to break cryptographic systems with no known weaknesses in the algorithm’s mathematical structure. Power Analysis Attack (PAA) is a type of SCA that exploits the relationship between the power consumption and secret key (secret part of input to some cryptographic process) information during the cryptographic device normal operation. PAA can be further divided into three categories: Simple Power Analysis (SPA), Differential Power Analysis (DPA) and Correlation Power Analysis (CPA). PAA was first …

Phylogeographic Study Of Ctenosaura Similis, Hasret Ozturk

Theses

The genus Ctenosaura (spiny-tailed iguanas) represents the most diverse group of iguanas with 18 currently recognized species. Ctenosaura similis has the most widespread ranges of all the Ctenosaura species, and extends from southern Mexico to Panama including many coastal islands. The purpose of this study is to explore the genetic diversity within C. similis and look for correlations between genetic relationships and biogeographic patterns related to the spread of the species. This study sequenced and aligned 1140 bp from the cytochrome b (cytb) locus for 159 individuals and 847-878 bp from the rhodopsin locus for 127 individuals. A total of …

Experimental Evaluate Gas Separation Using Ranuehilsch Vortex Tube, Ali Salah Omar Owiemer Omar Owiemer

Theses

Through experimental investigation, this study is offering a closer look into the performance of the vortex tube energy separation and a better understanding of the effect of the vortex tube length, diameter and internal tapering angle on the energy separation. Also the study addresses the effect of inlet pressure on the performance of the vortex tube and the effect of different working fluids (Air, H2 and O2). The vortex tube is a thermal static tube that was discovered by the French scientist George Ranque in 1933 and it is used to separate compressed gas flow into two different streams: one …

Principles And Applications Of Mechanical Dry Coating - Review And State-Of-The-Art, Sayani Bhaumik

Theses

Dry Coating of powders to form composite particulates has been firmly established and has garnered interest both in academia and industry due to its myriad applications. This thesis work is an attempt to map the progress of the dry coating technology from its incipient years in the '80s to the thriving practice in the present day. Dry coating is a relatively simple approach to coat powders with specific guest particles via mechanical means to produce composites with desired tailor-made properties, without the constraints of harmful emissions or huge capital investment. Composite particulates with enhanced flowability, high-temperature resistant properties, and modified …

Development Of A Finite Element Method For Light Activated Polymers, Craig Hamel

Theses

Traditional Shape Memory Polymers (SMPs) belong to a class of smart materials which have shown promise for a wide range of applications. They are characterized by their ability to maintain a temporary deformed shape and return to an original parent permanent shape. The first SMPs developed responded to changes in temperature by exploiting the difference in modulus and chain mobility through the glass transition temperature. However, in recent years, new SMPs have been developed that respond to other stimuli besides temperature; these can include electricity, magnetism, changes in chemical concentration, and even light.

In this thesis, we consider the photo-mechanical …

Characterizing Alma For Solar Observation, Yi Chai

Theses

ALMA (Atacama Large Millimeter/submillimeter Array) is an antenna array of 66 antennas located in northern Chile at 5000 meters altitude. It is the largest ground-based array operated at millimeter/submillimeter wavelengths. In this thesis, the advantages of using ALMA for solar observation are presented, together with the introduction of a campaign to commission ALMA for solar observations. Observation modes of the solar campaign are reviewed in Chapter 2. Methods for constructing images from single dish data as well as the procedure for processing interferometer data, including calibration and imaging, are given in Chapter 3. The CLEAN algorithm that is used for …

Modeling Of Electrical Behavior Of Graphene-Based Ultracapacitors, Patrick Dzisah

Theses

Graphene has been identified as a promising material for energy storage, especially for high performance ultracapacitors. Graphene-based ultracapacitors show high stability, significantly-improved capacitance and energy density with fast charging and discharging time at a high current density, due to enhanced ionic electrolyte accessibility in deeper regions. The surface area of a single graphene sheet is 2630 m2/g, substantially higher than values derived from Brunauer Emmett Teller (BET) surface area measurements of activated carbons used in the current electrochemical double layer capacitors.

In an ultracapacitor cell, chemically modified graphene (CMG) materials demonstrate high specific capacitances of 135 and 99 F/g in …

Design, Construction And Characterization Of A Wind Tunnel, Chang Ge

Theses

The wind tunnel is the most fundamental test equipment for aircraft testing and studying aerodynamics. Because of the complexity of the test-subject's geometry, it is difficult to study the aerodynamic pattern simply based on theoretical calculations. Most of the aerodynamics experiments still use wind tunnels. The progress of the wind tunnel is highly related to the advancements in air crafts. Aircraft manufacturing has pushed the wind tunnel technology forward. Wind tunnels can be categorized by the wind speed limit differences, which are controlled by the mechanism of the driving methods, structure applications, etc. In this case, we built a small …

Exact Genome Alignment, Nandini Ghosh

Theses

The increase in the volume of genomic data due to the decrease in the cost of whole genome sequencing techniques has opened up new avenues of research in the field of Bioinformatics, like comparative genomics and evolutionary dynamics. The fundamental task in these studies is to align the genome sequences accurately. Sequence alignment helps to identify regions of similarity between the sequences to establish their functional, evolutionary and structural relationship. The thesis investigates the performance of two sequence alignment programs LASTZ, a hash table based faster method and SSEARCH, a slower but more rigorous Smith-Waterman based approach, on whole genome …

Communication Risk And Strategy In Temporary Organizations, Shelley R. Mcivor

Theses

Communication is a critical and emerging metric for successful outcomes in the high-stakes field of project management. Professional management societies have quantified financial losses caused by ineffective communication. Consulting project management exemplifies a maximum communication risk environment - misunderstanding threatens project finances, strict deadlines, and technical benchmarks - exacerbated by the complexity of a temporary organization structure.

The context of work in a temporary organization adds layers of ambiguity to project communications - an ill-structured domain in technical communication terms. Formal study of communication in temporary organizations is relatively new. Recent studies are derived from engineering and business management perspectives. …

Thermal Properties Of Graphene, Vishal Vijay Nakhate

Theses

The two-dimensional (2D) monolayer structure of carbon atoms were initially considered as unstable. The 2D materials have recently been discovered and many researchers have started analyzing these materials. Graphene, a two-dimensional allotrope of graphite with sp2 bonded carbon atoms, is arranged in honeycomb structure. Graphene has excellent thermal conductivity and can be considered as a potential material for applications in the electronics industry where heating of materials is a serious concern.

In this study, thermal properties of p and n doped graphene nanosheets and nanoribbons are studied as function of percentage composition of the dopants and the direction of dissipation …

Unsupervised Gene Regulatory Network Inference On Microarray Data, Nidhi Radia

Theses

Obtaining gene regulatory networks (GRNs) from expression data is a challenging and crucial task. Many computational methods and algorithms have been developed to infer gene networks for gene expression data, which are usually obtained from microarray experiments. A gene network is a method to depict the relation among clusters of genes. To infer gene networks, the unsupervised method is used in this study. The two types of data used are time-series data and steady-state data. The data is analyzed using various tools containing different algorithms and concepts. GRNs from time-series data tools are obtained using the Time-delayed Algorithm for the …

Design, Construction And Characterization Ofa Magnetic Augmented Rotation System (Mars) Based Wind Turbine, Da Li

Theses

Magnetic Augmented Rotation System (MARS) works by magnetic field coupling, to transfer torque from the driver to the rotor without contact. This characteristic has significant applications to the wind turbine but research in combination of MARS and wind turbine has not been done in the literature. In this thesis, a small-scale wind turbine is designed, built and characterized in a prototype wind tunnel. The test results are analyzed and computer-aided software simulation is used as an auxiliary method to understand the mechanism of MARS. The power coefficient of this new wind turbine is estimated to be about 40%. The “gear …

Identifying Modifier Genes In Sma Model Mice, Weiting Xu

Theses

Spinal Muscular Atrophy (SMA) involves the loss of nerve cells called motor neurons in the spinal cord and is classified as a motor neuron disease, it affects 1 in 5000-10000 newborns, one of the leading genetic causes of infant death in USA. Mutations in the SMN1, UBA1, DYNC1H1 and VAPB genes cause spinal muscular atrophy. Extra copies of the SMN2 gene modify the severity of spinal muscular atrophy. Mutations in SMN1 (Motor Neuron 1) mainly causes SMA (Autosomal recessive inheritance). SMN1 gene mutations lead to a shortage of the SMN protein and SMN protein forms SMN complex …

A Voxel-Based Approach For Imaging Voids In Three-Dimensional Point Clouds, Katie N. Salvaggio

Theses

Geographically accurate scene models have enormous potential beyond that of just simple visualizations in regard to automated scene generation. In recent years, thanks to ever increasing computational efficiencies, there has been significant growth in both the computer vision and photogrammetry communities pertaining to automatic scene reconstruction from multiple-view imagery. The result of these algorithms is a three-dimensional (3D) point cloud which can be used to derive a final model using surface reconstruction techniques. However, the fidelity of these point clouds has not been well studied, and voids often exist within the point cloud. Voids exist in texturally difficult areas, as …

Symmetric Product Graphs, Evan Witz

Theses

We describe four types of hyperspace graphs; namely, the simultaneous and nonsimultaneous symmetric product graphs, as well as their respective layers. These hyperspace graphs are meant to be analogous to the concepts of hyperspaces in topology, in that they are constructed by taking in another graph as an input in the construction of the hyperspace graph. We establish subgraph relationship between these graphs and establish some properties on the orders and sizes of the graphs, as well as on the degrees of the individual vertices of these graphs. We establish that these graphs are connected (providing that the input graph …

X10 Comics: Reimagining The Sequential Narrative, Sten E. Mckinzie

Theses

At its core a comic book is a narrative told using a sequence of images or a sequential art narrative. There are a number of conventions, established early in the history of comics, which make the comic panel format a powerful tool for visual communication.

My thesis project examines these conventions and attempt to distinguish which ones are results of the unique nature of sequential art and which began as a byproduct of technological limitations. By doing so my goal is to take advantage of current technology by creating a new comic book format that integrates digital media while celebrating …

Exploring Property Based Aluminum Specifications., Naitik Gada

Theses

Aluminum recycling is imperative because of the steady increase in its consumption. Recycling creates a secondary supply stream, lowers production costs and significantly reduces energy use during the production cycle. One of the limiting factors to increased use of scrap in alloys is problematic tramp elements that accumulate in the scrap stream. Currently, alloy producers make use of blending models to assist in choosing from a large number of inputs (scrap sources, primary aluminum, and alloying elements) to manufacture a portfolio of alloys within specification. The goal is to present cost-effective strategies to increase scrap consumption under the applicable context …

Information Security Policy For E-Government In Saudi Arabia: Effectiveness, Vulnerabilities And Threats, Khaled Algarni

Theses

This study focuses on the issue of information security policy for e-government in Saudi Arabia. It evaluates the three fundamental pillars that determine data security such as effectiveness, vulnerabilities, and threats. The paper is seeking to reveal the risks of information security policy for e-government in Saudi Arabia as well as to examine the vulnerabilities and the effectiveness of the system.

The methodology applied inductive approach where both qualitative and quantitative research method were used. A survey by use of questionnaires and an interview was conducted.

Rematerialize, Eunmi Han

Theses

The universal thinking about jewelry is that it is an art form with monetary value. Often, people consider jewelry or body ornamentation to be a symbol of riches—precious items with great monetary value. As a result, most jewelers prefer to use precious metals, gemstones and the like, in its production.

This thesis explores the meanings and forms of jewelry that does not incorporate such precious materials. Instead of focusing on the value of the materials, their other qualities and the alternative aesthetics will be approached and discussed. Creating new meanings and visual designs that address the beauty, style, wearability, and …

Museums And Visitors With Autism: An Overview Of Programs, Rachel Varner

Theses

Across the world, several museums are committed to accessibility and accommodations for the general public, such as closed captions for the D/HH (deaf and hard-of-hearing) visitors and ramps for wheelchair users. However, not all disabilities and disorders are visible. When it comes to working with people who have a specific disability or disorder, it is critical that museum professionals be aware of what should be done to ensure that visitors with disabilities or disorders have a pleasant experience in the museum. Numerous museums have already created programs for people with specific disabilities or disorders. Workshops about disabilities and disorders should …

Allocation Of Workers Utilizing Models With Learning, Forgetting, And Various Work Structures, Austin T. Chacosky

Theses

Much of the literature on cross-training and worker assignment problems focus on simulating production systems under cross-training methods. Many have found that for specific systems some methods of allocating workers are better performing than others in terms of overall productivity and ability to deal with change. This has lead researchers to create mathematical programming models with a goal of finding optimal levels of cross-training by changing worker allocations. Learning and forgetting curves have been a key method to improve the solutions produced by the optimization models, but learning curves are often nonlinear causing increased solving times. Because of this, most …

Frequency Constraints On D.C. Biasing In Deep Submicron Technologies, Jonathan Thomas Zimmermann

Theses

The progression of technology has required smaller devices to achieve faster circuits and more power-efficient systems. However, with supply voltage and device intrinsic gain decreasing, device biasing in deep sub-micron technologies can be challenging. A low-voltage current source is analyzed in a 28 nm CMOS, 0.85 V supply, technology to take into account undesirable effects introduced by aggressively scaled technologies. The analysis includes intrinsic gain degradation as well as short-channel effects to create a more accurate design methodology. Amplifier design challenges in deep sub-micron technologies are discussed along with a DAC bias correction technique. Frequency dependence of output resistance for …

Leadership Cultural Values Of United Arab Emirates-The Case Of United Arab Emirates University, Ebtesam Ali Alteneiji

Theses

UAE is a young country with a young population that has witnessed tremendous changes over the past decades. There has not been much research about the cultural values of the UAE in generational perspectives, and there have been rapid changes. Therefore, this study aimed at exploring systematic changes in leadership cultural values among the older and the younger generations of the United Arab Emirates. The author utilized Hofstede’s (VSM08) instrument to survey undergraduate students, administrators and faculty at UAE University.

The study found no significant differences between the younger and older generations’ tolerance to unequal distribution of power (power distance), …