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Articles 140641 - 140670 of 303061

Full-Text Articles in Physical Sciences and Mathematics

Automatic Detection And Denoising Of Signals In Large Geophysical Datasets, Gabriel O. Trisca Aug 2015

Automatic Detection And Denoising Of Signals In Large Geophysical Datasets, Gabriel O. Trisca

Boise State University Theses and Dissertations

To fully understand the complex interactions of various phenomena in the natural world, scientific disciplines such as geology and seismology increasingly rely upon analyzing large amounts of observations. However, data collection is growing at a faster rate than what is currently possible to analyze through traditional approaches. These datasets, supplied by the increasing use of sensors and remote sensing, require specialized computer programs to effectively analyze complex and expansive volumes of data.

Elaborating on existing geophysical data processing approaches for infrasound data collected from an avalanche-prone area, this project proposes new techniques for processing large geophysical datasets. These improved techniques …


Monodromy Representation Of The Braid Group, Phillip W. Hart Aug 2015

Monodromy Representation Of The Braid Group, Phillip W. Hart

Boise State University Theses and Dissertations

In the mid 1980s, it was realized that solutions to what is known as the Knizhnik- Zamolodchikov equation, or KZ equation, provided a pathway to representations of the braid group Bn on n strands, with early mathematical treatments of the topic by Kohno and Drinfel'd. Such representations are typically referred to as monodromy representations of the braid group along solutions of the KZ equation. These linear representations are of great interest within topology, integral to the construction of isotopy invariants of knots and links, such as the well known Jones polynomial. More current discussions of the KZ equation and …


Geometry Of Scales, Kyle Stephen Austin Aug 2015

Geometry Of Scales, Kyle Stephen Austin

Doctoral Dissertations

The geometry of coverings has widely been used throughout mathematics and it has recently been a promising tool for resolving longstanding problems in topological rigidity such as the Novikov conjecture and Gromov's positive scalar curvature conjecture. We discuss rigidity conjectures and how large scale geometry is being applied in order to resolve them for important cases.

Not only is small scale and large scale geometry very applicable to understanding global geometry of objects, but it is an interesting topic in its own right. The first chapter of this paper is devoted to building a framework for small scale geometry alongside …


Numerical Methods For Deterministic And Stochastic Phase Field Models Of Phase Transition And Related Geometric Flows, Yukun Li Aug 2015

Numerical Methods For Deterministic And Stochastic Phase Field Models Of Phase Transition And Related Geometric Flows, Yukun Li

Doctoral Dissertations

This dissertation consists of three integral parts with each part focusing on numerical approximations of several partial differential equations (PDEs). The goals of each part are to design, to analyze and to implement continuous or discontinuous Galerkin finite element methods for the underlying PDE problem.

Part One studies discontinuous Galerkin (DG) approximations of two phase field models, namely, the Allen-Cahn and Cahn-Hilliard equations, and their related curvature-driven geometric problems, namely, the mean curvature flow and the Hele-Shaw flow. We derive two discrete spectrum estimates, which play an important role in proving the sharper error estimates which only depend on a …


Versatile Synthetic Methods For Photoluminescent Pyrylium Tosylates, Jung Jae Koh Aug 2015

Versatile Synthetic Methods For Photoluminescent Pyrylium Tosylates, Jung Jae Koh

UNLV Theses, Dissertations, Professional Papers, and Capstones

Pyrylium salts are an important class of cationic organic molecules that exhibit good absorption, fluorescence, and photo-induced electron transfer properties. They can also function as precursors for synthesis of different heterocyclic organic molecules such as furan, pyridine, pyridinium salt, and betaine dyes. This thesis describes versatile methods of synthesis for a series of 2,4,6-triarylsubstitued pyrylium tosylates with different substituents by using p-toluenesulfonic acid monohydrate instead of conventional acid catalysts including perchloric acid or boron trifluoride diethyl etherate that accompany explosion danger and difficult storage problem, respectively. The chemical structures were established by 1H and 13C NMR spectroscopic techniques …


Control Of Coupled Oscillator Networks With Application To Microgrid Technologies, Per Sebastian Skardal, Alex Arenas Aug 2015

Control Of Coupled Oscillator Networks With Application To Microgrid Technologies, Per Sebastian Skardal, Alex Arenas

Faculty Scholarship

The control of complex systems and network-coupled dynamical systems is a topic of vital theoretical importance in mathematics and physics with a wide range of applications in engineering and various other sciences. Motivated by recent research into smart grid technologies, we study the control of synchronization and consider the important case of networks of coupled phase oscillators with nonlinear interactions—a paradigmatic example that has guided our understanding of self-organization for decades. We develop a method for control based on identifying and stabilizing problematic oscillators, resulting in a stable spectrum of eigenvalues, and in turn a linearly stable synchronized state. The …


On The Existence And Uniqueness Of Static, Spherically Symmetric Stellar Models In General Relativity, Josh Michael Lipsmeyer Aug 2015

On The Existence And Uniqueness Of Static, Spherically Symmetric Stellar Models In General Relativity, Josh Michael Lipsmeyer

Masters Theses

The "Fluid Ball Conjecture" states that a static stellar model is spherically symmetric. This conjecture has been the motivation of much work since first mentioned by Kunzle and Savage in 1980. There have been many partial results( ul-Alam, Lindblom, Beig and Simon,etc) which rely heavily on arguments using the positive mass theorem and the equivalence of conformal flatness and spherical symmetry. The purpose of this paper is to outline the general problem, analyze and compare the key differences in several of the partial results, and give existence and uniqueness proofs for a particular class of equations of state which represents …


Morphology-Property Relationship For Binary Organic Thin Films, Alyssa Lynn Griffin Aug 2015

Morphology-Property Relationship For Binary Organic Thin Films, Alyssa Lynn Griffin

Master's Theses

Organic thin films can be readily mass-produced through solution-based fabrication methods including ink-printing and solution-casting because their light weight, flexibility, and inexpensive sources. Their applications range from organic field-effect transistors (OFET), organic solar cells (OSC), to organic light emitting diodes (OLEDs). Compared with pure component films, binary organic thin films (BOTF) allows for novel characteristics and specialized features to handle more demanding tasks. Due to the complex intermolecular interactions in BOTF, various microscopic phases with different morphological and electronic properties may be formed and this information is difficult to extract through conventional bulk measurements.

Organic thin films can be readily …


Mechanisms For Social Influence, Jeremy David Auerbach Aug 2015

Mechanisms For Social Influence, Jeremy David Auerbach

Masters Theses

Throughout the thesis, I study mathematical models that can help explain the dependency of social phenomena in animals and humans on individual traits. The first chapter investigates consensus building in human groups through communication of individual preferences for a course of action. Individuals share and modify these preferences through speaker listener interactions. Personality traits, reputations, and social networks structures effect these modifications and eventually the group will reach a consensus. If there is variation in personality traits, the time to reach consensus is delayed. Reputation models are introduced and explored, finding that those who can best estimate the average initial …


Face Recognition Under Varying Illuminations, Mohammadreza Faraji Aug 2015

Face Recognition Under Varying Illuminations, Mohammadreza Faraji

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Face recognition under illumination is really challenging. This dissertation proposes four effective methods to produce illumination-invariant features for images with various levels of illuminations. The proposed methods are called logarithmic fractal dimension (LFD), eight local directional patterns (ELDP), adaptive homomorphic eight local directional pat- terns (AH-ELDP), and complete eight local directional patterns (CELDP), respectively.

LFD, employing the log function and the fractal analysis (FA), produces a logarithmic fractal dimension (LFD) image that is illumination-invariant. The proposed FA feature-based method is an effective edge enhancer technique to extract and enhance facial features such as eyes, eyebrows, nose, and mouth.

The proposed …


Image Blur Detection With Two-Dimensional Haar Wavelet Transform, Sarat Kiran Andhavarapu Aug 2015

Image Blur Detection With Two-Dimensional Haar Wavelet Transform, Sarat Kiran Andhavarapu

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Efficient detection of image blur and its extent is an open research problem in computer vision. Image blur has a negative impact on image quality. Blur is introduced into images due to various factors including limited contrast, improper exposure time or unstable device handling. Toward this end, an algorithm is presented for image blur detection with the use of Two-Dimensional Haar Wavelet transform (2D HWT). The algorithm is experimentally compared with two other image blur detection algorithms frequently cited in the literature. When evaluated over a sample of images, the algorithm performed on par or better than the two other …


Comment On "Role Of Potentials In The Aharonov-Bohm Effect", Yakir Aharonov, Eliahu Cohen, Daniel Rohrlich Aug 2015

Comment On "Role Of Potentials In The Aharonov-Bohm Effect", Yakir Aharonov, Eliahu Cohen, Daniel Rohrlich

Mathematics, Physics, and Computer Science Faculty Articles and Research

Are the electromagnetic scalar and vector potentials dispensable? Vaidman [Phys. Rev. A 86, 040101(R) (2012)] has suggested that local interactions of gauge-invariant quantities, e.g., magnetic torques, suffice for the description of all quantum electromagnetic phenomena. We analyze six thought experiments that challenge this suggestion. All of them have explanations in terms of local interactions of gauge-dependent quantities, and, in addition, some have explanations in terms of nonlocal interactions of gauge-invariant quantities. We claim, however, that two of our examples have no gauge-invariant formal description and that, in general, no local description can dispense with electromagnetic potentials.


Mobile Cloud Computing Based Non Rigid Registration For Image Guided Surgery, Arun Brahmavar Vishwanatha Aug 2015

Mobile Cloud Computing Based Non Rigid Registration For Image Guided Surgery, Arun Brahmavar Vishwanatha

Computer Science Theses & Dissertations

In this thesis we present the design and implementation of a Mobile Cloud computing platform for non-rigid registration required in Image Guided Surgery (MCIGS). MCIGS contributes in flexible, portable and accurate alignment of pre-operative brain data with intra-operative MRI, for image guided diagnosis and therapy and endoscopic skull base surgery. Improved precision of image guided therapy and specifically neurosurgery procedures is known to result in the improved prognosis for brain tumor patients. MCI GS system is tested with Physics Based Non-Rigid Registration method form ITK. Our preliminary results for brain images indicate that the proposed system over Wi-Fi can be …


Ad-Hoc Automated Teller Machine Failure Forecast And Field Service Optimization, Michelle L. F. Cheong, Ping Shung Koo, B. Chandra Babu Aug 2015

Ad-Hoc Automated Teller Machine Failure Forecast And Field Service Optimization, Michelle L. F. Cheong, Ping Shung Koo, B. Chandra Babu

Research Collection School Of Computing and Information Systems

As part of its overall effort to maintain good customer service while managing operational efficiency and reducing cost, a bank in Singapore has embarked on using data and decision analytics methodologies to perform better ad-hoc ATM failure forecasting and plan the field service engineers to repair the machines. We propose using a combined Data and Decision Analytics Framework which helps the analyst to first understand the business problem by collecting, preparing and exploring data to gain business insights, before proposing what objectives and solutions can and should be done to solve the problem. This paper reports the work in analyzing …


On Mining Lifestyles From User Trip Data, Meng-Fen Chiang, Ee-Peng Lim Aug 2015

On Mining Lifestyles From User Trip Data, Meng-Fen Chiang, Ee-Peng Lim

Research Collection School Of Computing and Information Systems

Large cities today are facing major challenges in planning and policy formulation to keep their growth sustainable. In this paper, we aim to gain useful insights about people living in a city by developing novel models to mine user lifestyles represented by the users' activity centers. Two models, namely ACMM and ACHMM, have been developed to learn the activity centers of each user using a large dataset of bus and subway train trips performed by passengers in Singapore. We show that ACHMM and ACMM yield similar accuracies in location prediction task. We also propose methods to automatically predict "home", "work" …


Event Detection: Exploiting Socio-Physical Interactions In Physical Spaces, Kasthuri Jayarajah, Archan Misra, Xiao-Wen Ruan, Ee-Peng Lim Aug 2015

Event Detection: Exploiting Socio-Physical Interactions In Physical Spaces, Kasthuri Jayarajah, Archan Misra, Xiao-Wen Ruan, Ee-Peng Lim

Research Collection School Of Computing and Information Systems

This paper investigates how digital traces of people's movements and activities in the physical world (e.g., at college campuses and commutes) may be used to detect local, short-lived events in various urban spaces. Past work that use occupancy-related features can only identify high-intensity events (those that cause large-scale disruption in visit patterns). In this paper, we first show how longitudinal traces of the coordinated and group-based movement episodes obtained from individual-level movement data can be used to create a socio-physical network (with edges representing tie strengths among individuals based on their physical world movement & collocation behavior). We then investigate …


Applying Geocaching Principles To Site-Based Citizen Science And Eliciting Reactions Via A Technology Probe, Matthew A. Dunlap, Anthony Tang, Saul Greenberg Aug 2015

Applying Geocaching Principles To Site-Based Citizen Science And Eliciting Reactions Via A Technology Probe, Matthew A. Dunlap, Anthony Tang, Saul Greenberg

Research Collection School Of Computing and Information Systems

Site-based citizen science occurs when volunteers work with scientists to collect data at particular field locations. The benefit is greater data collection at lesser cost. Yet difficulties exist. We developed SCIENCECACHING, a prototype citizen science aid designed to mitigate four specific problems by applying aspects from another thriving location-based activity: geocaching as enabled by mobile devices. Specifically, to ease problems in data collection, SCIENCECACHING treats sites as geocaches: Volunteers find sites opportunistically via geocaching methods and use equipment and other materials pre-stored in cache containers. To ease problems in data validation, SCIENCECACHING flags outlier data as it is entered so …


Degradation Science: Mesoscopic Evolution And Temporal Analytics Of Photovoltaic Energy Materials, Roger H. French, Rudolf Podgornik, Timothy J. Peshek, Laura S. Bruckman, Yifan Xu, Nicholas R. Wheeler, Abdulkerim Gok, Yang Hu, Mohammad A. Hossain, Devin A. Gordon, Pei Zhao, Jiayang Sun, Guo-Qiang Zhang Aug 2015

Degradation Science: Mesoscopic Evolution And Temporal Analytics Of Photovoltaic Energy Materials, Roger H. French, Rudolf Podgornik, Timothy J. Peshek, Laura S. Bruckman, Yifan Xu, Nicholas R. Wheeler, Abdulkerim Gok, Yang Hu, Mohammad A. Hossain, Devin A. Gordon, Pei Zhao, Jiayang Sun, Guo-Qiang Zhang

Faculty Scholarship

Based on recent advances in nanoscience, data science and the availability of massive real-world datastreams, the mesoscopic evolution of mesoscopic energy materials can now be more fully studied. The temporal evolution is vastly complex in time and length scales and is fundamentally challenging to scientific understanding of degradation mechanisms and pathways responsible for energy materials evolution over lifetime. We propose a paradigm shift towards mesoscopic evolution modeling, based on physical and statistical models, that would integrate laboratory studies and real-world massive datastreams into a stress/mechanism/response framework with predictive capabilities. These epidemiological studies encompass the variability in properties that affect performance …


Lang’S Universal Molecule Algorithm, John C. Bowers, Ileana Streinu Aug 2015

Lang’S Universal Molecule Algorithm, John C. Bowers, Ileana Streinu

Computer Science: Faculty Publications

Robert Lang’s Universal Molecule algorithm, a landmark in modern computational origami, is the main component of his widely used Tree Maker program for origami design. It computes a crease pattern of a convex polygonal region, starting with a compatible metric tree. Although it has been informally described in several publications, neither the full power nor the inherent limitations of the method are well understood. In this paper we introduce a rigorous mathematical formalism to relate the input metric tree, the output crease pattern and the folded uniaxial origami base produced by the Universal Molecule algorithm. We characterize the family of …


Inkball Models For Character Localization And Out-Of-Vocabulary Word Spotting, Nicholas Howe Aug 2015

Inkball Models For Character Localization And Out-Of-Vocabulary Word Spotting, Nicholas Howe

Computer Science: Faculty Publications

Inkball models have previously been used for keyword spotting under the whole word query-by-image paradigm. This paper applies inkball methods to string-based queries for the first time, using synthetic models composed from individual characters. A hybrid system using both query-by-string for unknown words and query-by-example for known words outperforms either approach by itself on the George Washington and Parzival test sets. In addition, inkball character models offer an explanatory tool for understanding handwritten markings. In combination with a transcript they can help to to attribute each ink pixel of a word image to specific letters, resulting in highquality character segmentations.


Forensic Significance Of Teal Colored Cashmere And Black Acrylic Fibers, Nicole M. Martin Jul 2015

Forensic Significance Of Teal Colored Cashmere And Black Acrylic Fibers, Nicole M. Martin

Nicole M Martin

Forensic Significance of Teal Colored Cashmere and Black Acrylic Fibers Textile fibers are a valuable type of trace evidence within forensic cases. They have the ability to connect a perpetrator to a victim and or a crime scene. Some types of fibers are more prevalent than others. The purpose of this research was to conduct a target fiber study in order to determine the significance of the selected fibers in a forensic case. Two fibers were selected from two different garments, black acrylic fiber and a teal colored cashmere fiber. Unknown fibers were collected from three local clothing stores and …


On The Topology Of The Permutation Pattern Poset, Peter R. W. Mcnamara, Einar Steingrímsson Jul 2015

On The Topology Of The Permutation Pattern Poset, Peter R. W. Mcnamara, Einar Steingrímsson

Peter R. W. McNamara

The set of all permutations, ordered by pattern containment, forms a poset.  This paper presents the first explicit major results on the topology of intervals in this poset.  We show that almost all (open) intervals in this poset have a disconnected subinterval and are thus not shellable.  Nevertheless, there seem to be large classes of intervals that are shellable and thus have the homotopy type of a wedge of spheres.  We prove this to be the case for all intervals of layered permutations that have no disconnected subintervals of rank 3 or more.  We also characterize in a simple way …


Chaotic Behavior In Monetary Systems: Comparison Among Different Types Of Taylor Rule, Reza Moosavi Mohseni Dr., Wenjun Zhang, Jiling Cao Jul 2015

Chaotic Behavior In Monetary Systems: Comparison Among Different Types Of Taylor Rule, Reza Moosavi Mohseni Dr., Wenjun Zhang, Jiling Cao

Reza Moosavi Mohseni

The aim of the present study is to detect the chaotic behavior in monetary economic relevant dynamical system. The study employs three different forms of Taylor rules: current, forward, and backward looking. The result suggests the existence of the chaotic behavior in all three systems. In addition, the results strongly represent that using expectations in policy rule especially rational expectation hypothesis can increase complexity of the system and leads to more chaotic behavior.


Genetic Variability Of The 5-Enolpyruvylshikimate-3-Phosphate (Epsp) Synthase Gene In Round-Up™ Resistant Soil Bacteria, Seth Steenwyk, Hannah Van Maanen, Jeff Ploegstra Jul 2015

Genetic Variability Of The 5-Enolpyruvylshikimate-3-Phosphate (Epsp) Synthase Gene In Round-Up™ Resistant Soil Bacteria, Seth Steenwyk, Hannah Van Maanen, Jeff Ploegstra

Faculty Work Comprehensive List

Global use of Round-up™ has had a profound effect on agricultural systems. While there is a clear challenge with the emergence of resistant weeds, less emphasis has been placed on its impacts regarding the soil ecosystem. In this study, we sought to identify glyphosate resistance in two specific soil bacteria, Bacillus subtilis and Pseudomonas syringae pv. glycinea. To accomplish this purpose, selective media and colony PCR were used to isolate and identify colonies with glyphosate resistance. The presence of glyphosate resistance in soil bacteria was verified, and continuing work is being done to analyze sequence data that may lead to …


Benthic Invertebrate Communities And Habitat Characterization Of The Pourtalès Terrace, Florida With Analysis Of The Deepwater Coral Habitat Areas Of Particular Concern And The East Hump Marine Protected Area, Jana K. Ash Jul 2015

Benthic Invertebrate Communities And Habitat Characterization Of The Pourtalès Terrace, Florida With Analysis Of The Deepwater Coral Habitat Areas Of Particular Concern And The East Hump Marine Protected Area, Jana K. Ash

HCNSO Student Theses and Dissertations

The Pourtalès Terrace is a gently curved, narrow triangular platform that parallels the Florida Keys for 213 km running from southern Key Largo to between Key West and the Marquesas Keys. The main Terrace surface begins in 200 m and dips gently to approximately 450 m, where the Pourtalès Escarpment slopes steeply to the deep floor of the southern Straits of Florida. The Terrace platform exhibits a wide variety of Neogene-age geological features, including high-relief ledges, mounds, sinkholes and deep-water biogenic build-ups called bioherms. Previous research revealed dense and diverse benthic assemblages dominated by stylasterid hydrocorals, octocorals and sponges.

Many …


Teaching Big Data By Three Levels Of Projects, Jianjun Yang, Ju Shen Jul 2015

Teaching Big Data By Three Levels Of Projects, Jianjun Yang, Ju Shen

Computer Science Faculty Publications

Big Data is a new topic and it is very hot nowadays. However, it is difficult to teach Big Data effectively by regular lecture. In this paper, we present a unique way to teach students Big Data by developing three levels of projects from easy to difficult. The three levels projects are initializing project, designing project, and comprehensive projects. They are developed to involve students in Big Data, train students' skills to analyze concrete problems of Big Data, and develop students' creative abilities and their abilities to solve real setting problems.


An Indistinguishability Model For Evaluating Diverse Classes Of Phishing Attacks And Quantifying Attack Efficacy, Narasimha Shashidhar, Lei Chen Jul 2015

An Indistinguishability Model For Evaluating Diverse Classes Of Phishing Attacks And Quantifying Attack Efficacy, Narasimha Shashidhar, Lei Chen

Department of Information Technology Faculty Publications

Phishing is a growing threat to Internet users and causes billions of dollars in damage every year. While there are a number of research articles that study the tactics, techniques and procedures employed by phishers in the literature, in this paper, we present a theoretical yet practical model to study this menacing threat in a formal manner. While it is common folklore knowledge that a successful phishing attack entails creating messages that are indistinguishable from the natural, expected messages by the intended victim, this concept has not been formalized. Our model attempts to capture a phishing attack in terms of …


Competitive Halide Binding By Halogen Versus Hydrogen Bonding: Bis-Triazole Pyridinium, Binod Nepal, Steve Scheiner Jul 2015

Competitive Halide Binding By Halogen Versus Hydrogen Bonding: Bis-Triazole Pyridinium, Binod Nepal, Steve Scheiner

Chemistry and Biochemistry Faculty Publications

The binding of F-, Cl-, Br-, and I- anions by bis‐triazole‐pyridine (BTP) was examined by quantum chemical calculations. There is one H atom on each of the two triazole rings that chelate the halide via H bonds. These H atoms were replaced by halogens Cl, Br, and I, thus substituting H bonds by halogen bonds. I substitution strongly enhances the binding; Br has a smaller effect, and Cl weakens the interaction. The strength of the interaction is sensitive to the overall charge on the BTP, rising as the binding agent becomes singly and then doubly positively charged. The strongest preference …


On Supervised And Unsupervised Methodologies For Mining Of Text Data., Tanmay Basu Dr. Jul 2015

On Supervised And Unsupervised Methodologies For Mining Of Text Data., Tanmay Basu Dr.

Doctoral Theses

The supervised and unsupervised methodologies of text mining using the plain text data of English language have been discussed. Some new supervised and unsupervised methodologies have been developed for effective mining of the text data after successfully overcoming some limitations of the existing techniques.The problems of unsupervised techniques of text mining, i.e., document clustering methods are addressed. A new similarity measure between documents has been designed to improve the accuracy of measuring the content similarity between documents. Further, a hierarchical document clustering technique is designed using this similarity measure. The main significance of the clustering algorithm is that the number …


Discovery Over Application: A Case Study Of Misaligned Incentives In Software Engineering, Eric F. Rizzi Jul 2015

Discovery Over Application: A Case Study Of Misaligned Incentives In Software Engineering, Eric F. Rizzi

Department of Computer Science and Engineering: Dissertations, Theses, and Student Research

In this thesis, we present evidence that there is an under-emphasis on the application of software systems in Software Engineering research, affecting the advancement of the field as a whole. Specifically, we perform a case-study on KLEE, a tool with over 1000 citations. We made improvements that consisted of fixing performance bugs and implementing optimizations that have become common practice, increasing KLEE's performance by 2-11X. To understand how techniques proposed in the literature would be affected by these improvements, we analyzed 100 papers that cited the original KLEE paper. From this analysis we found two things. First, it is clear …