Physical Sciences and Mathematics Commons^™

Hydrogen Storage In Hypercrosslinked Polystyrene And Li-Mg-N-H Complex Hydride, Dervis Emre Demirocak

USF Tampa Graduate Theses and Dissertations

In this dissertation, hydrogen storage enhancement in hypercrosslinked polystyrene, effects of single walled carbon nanotubes (SWCNTs) supported ruthenium (Ru) catalyst on the kinetics and ammonia suppression in the LiNH2-MgH2 complex hydride system and the accuracy of hydrogen storage measurements are investigated in detail.

High surface area physisorption materials are of interest for room temperature hydrogen storage enhancement by spillover. Six different commercially available hypercrosslinked polystyrenes are screened by considering the specific surface area, average pore size, pore volume, and adsorption enthalpy. MN270 is selected mainly due to its high surface area and narrow pores for investigation of the spillover enhancement …

Modeling State Transitions With Automata, Egor Dolzhenko

USF Tampa Graduate Theses and Dissertations

Models based on various types of automata are ubiquitous in modern science. These models allow reasoning about deep theoretical questions and provide a basis for the development of efficient algorithms to solve related computational problems. This work discusses several types of automata used in such models, including cellular automata and mandatory results automata.

The first part of this work is dedicated to cellular automata. These automata form an important class of discrete dynamical systems widely used to model physical, biological, and chemical processes. Here we discuss a way to study the dynamics of one-dimensional cellular automata through the theory of …

A Study Of Permutation Polynomials Over Finite Fields, Neranga Fernando

USF Tampa Graduate Theses and Dissertations

Let p be a prime and q = p^k. The polynomial g_n,q isin F_p[x] defined by the functional equation Sigma_{a isin Fq} (x+a)ⁿ = g_n,q(x^q- x) gives rise to many permutation polynomials over finite fields. We are interested in triples (n,e;q) for which g_n,q is a permutation polynomial of F_q^e. In Chapters 2, 3, and 4 of this dissertation, we present many new families of permutation polynomials in the form of g_n,q. The permutation behavior of g_n,q is becoming increasingly more …

Assessment Of A Modified Double Agar Layer Method To Detect Bacteriophage For Assessing The Potential Of Wastewater Reuse In Rural Bolivia, Sakira N. Hadley

USF Tampa Graduate Theses and Dissertations

Water scarcity is a global concern that impacts many developing countries, forcing people to depend on unclean water sources for domestic, agricultural, and industrial needs. Wastewater is an alternative water source that contains nutrients needed for crop growth. Wastewater reuse for agriculture can cause public health problems because of human exposure to pathogens. Pathogen monitoring is essential to evaluate the compliance of wastewater with established World Health Organization (WHO) and U.S. Environmental Protection Agency (EPA) wastewater reuse guidelines. Indicator organisms are commonly used to detect pathogens in water and wastewater because they are quick and easy to measure, non-pathogenic, and …

Spatial And Temporal Trends Of Snowfall In Central New York - A Lake Effect Dominated Region, Justin Joseph Hartnett

USF Tampa Graduate Theses and Dissertations

Central New York is located in one of the snowiest regions in the United States, with the city of Syracuse, New York the snowiest metropolis in the nation. Snowfall in the region generally begins in mid-November and lasts until late-March. Snow accumulation occurs from a multitude of conditions: frontal systems, mid-latitude cyclones, Nor'easters, and most notably lake-effect storms. Lake effect snowfall (LES) is a difficult parameter to forecast due to the isolated and highly variable nature of the storm. Consequently, studies have attempted to determine changes in snowfall for lake-effect dominated regions. Annual snowfall patterns are of particular concern as …

Hospital Charges At Birth And Frequency Of Rehospitalizations And Acute Care Visits Over The First Year Of Life, Katherine D. Cuevas, Debra R. Silver, Dorothy Brooten, Joanne M. Youngblut, Charles M. Bobo

Nicole Wertheim College of Nursing and Health Sciences

The proportion of preterm and low-birth-weight infants has been growing steadily for two decades. Most of the more than $10 billion spent on neonatal care in the United States in 2003 was spent on the 12.3% of infants who were born preterm. Research has shown higher initial hospital costs and a higher rate of acute care visits and rehospitalization for preterm and low-birth-weight infants, but only a limited number of studies of the cost of prematurity that follow infants through the first year of life have been conducted.

This study is a secondary analysis of data on a subset of …

Creating A User Satisfaction Index From A Parsimonious Survey Instrument, Brian Barthel

All Graduate Theses, Dissertations, and Other Capstone Projects

In this paper we present a comprehensive method for creating a user satisfaction index using a survey instrument. First we construct a parsimonious survey instrument, using the PageRank Centrality, to measure attributes of user satisfaction. Then confirmatory factor analysis is applied to extract ``weights'' on the questions that are used in a linear model of computing the user satisfaction index. Throughout the paper an analysis of an existing data set is implemented to illustrate the proposed method. In addition the validity of the confirmatory factor model is tested using bootstrap sampling.

Improving Gesture Recognition Performance Using The Dynamic Space-Time Warp Algorithm, Danny Allen Hanson

Computer Science and Engineering Theses

The DSTW algorithm was originally used as the fundamental algorithm for a gesture recognition software. When the need arose for implementing gesture recognition on-board a robotic vehicle, the original recognition software needed to undergo several changes in order to meet the requirements of the target platform. The original software was written in Matlab and had to be ported into a native language in order to operate on the new platform. To support experiments needed to select a distance and t function, the new code needed to be designed to support dynamic binding of distance and transition (t) functions. The software …

Learning Equivalent Input Channel Mappings And Generalized Features For Pattern Transfer, Houtan Rahmanian

Computer Science and Engineering Theses

In many real-world modeling applications, it is needed to detect the origin of the patterns of the input data in addition to find the patterns themselves. Having the input data generated by a systematically organized set of input channels is very common in these applications. These input channels might also be of the same type. Therefore, the same pattern might be observed on different sets of input channels of the data, while it is caused by the one source in different localities. Sparse coding is a very powerful method for learning high-level patterns (i.e. high-level features) from raw data input. …

Detection Of Fingers With A Depth Based Hand-Detector In Static Frames, Sanjay Vasudeva Iyer

Computer Science and Engineering Theses

This thesis presents a method for a finger detection system. It is assumed that the user taps their fingers on a table, and that the camera is placed on the same table in front of their fingers. This setup is motivated by the application of analyzing the movement of fingers in patients engaging in physical therapy. Fingers are detected in static images, which is a more challenging task than detecting and tracking fingers in videos which are based on motion.The Microsoft Kinect sensor has been used as a source for data, and it provides color and depth images at each …

Lilac: Architecture For Anonymous Light Weight Communication, Ankit Upadhyaya

Computer Science and Engineering Theses

We present lilac; a circuit based low latency anonymous light weight instant messaging communication system. This browser based chat platform provides anonymity in context with unlinkability and unobservability for the secured real-time communication. The system uses a relay based anonymization mechanism where circuits are built and routed over a set of trusted nodes in the network. Unlike other typical instant messaging systems, Lilac uses user pseudonymity and ephemeral message exchange, which eliminates conventional user registration and storing the messages for the future retrieval; this leaves no footprints behind in the system in terms of user information, who talks to whom …

Dovetail: Stronger Anonymity In Next-Generation Internet Routing, Jody Mark Sankey

Computer Science and Engineering Theses

Current low-latency anonymity systems use complex overlay networks to conceal a user's IP address, introducing significant latency and network efficiency penalties compared to normal Internet usage. Rather than this obfuscation of network identity through higher level protocols, we recommend a more direct solution: a routing protocol that allows communication without exposing network identity, providing a strong foundation for Internet privacy, while allowing identity to be defined in those higher level protocols where it adds value. We propose Dovetail, a next-generation Internet routing protocol that provides anonymity against an active attacker located at any single point within the network. Key design …

Modeling An Intelligent Intruder In A Region Monitored By A Wireless Sensor Network, Sriram Srinivasan

Computer Science and Engineering Theses

Monitoring to detect unauthorized border crossing is very important for protecting national security. To accomplish this by continuous physical monitoring by border patrol agents is impractical. Networks of low-cost wireless sensors have been identified as a useful tool in monitoring with minimal human intervention. However, ensuring the effectiveness of unattended monitoring against an intelligent intruder is difficult, since the intruder can probe the system for weaknesses. To better understand the capabilities of such an intruder, we propose a model for an intelligent intruder whose purpose is to find a detection-free path across the border by which he could cross back …

Sign Gesture Spotting In American Sign Language Using Dynamic Space Time Warping, Srujana Gattupalli

Computer Science and Engineering Theses

American Sign Language (ASL) is the primary sign language used by approximately 500,000 deaf and hearing-impaired people in the United States and Canada. ASL is a visually perceived, gesture-based language that employs signs made by moving the hands combined with facial expressions and postures of the body. There are several software tools available online to learn signs for a given word but there is no software that gives the meaning of any sign video. If we need to search or look up documents containing any word we can just type it in search engines like Google, Bing etc. but if …

Development And Simulation Of Focus Of Attention Using Reinforcement Learning And Function Approximation, Stephen Ratz

Computer Science and Engineering Theses

Without short-term memory, people would have little hope to learn and accomplish tasks. The same can be said for artificially intelligent agents. Often referred as Miller's Law, the number of working objects that a human can hold in working memory is around seven. For an AI agent, the cost of keeping additional memory blocks is exponential. Other issues to consider are what to keep in memory and for how long. Only a few of many of an agent's previous steps may be important to hold on to. This thesis project attempts to train an intelligent agent to learn what to …

A Source Code Search Engine For Keyword Based Structural Relationship Search, Asheq Hamid

Computer Science and Engineering Theses

In an Object Oriented Program, we often see that a package contains several classes, a class contains several methods, a method calls other methods. We may say, there is a contains relationship between a package and a class or a calls relationship between two methods. We refer to these relationships as structural relationships. There may be other structural relationships apart from contains or calls in the source code. A software developer may sometime want to search for structural relationships within source code. She may prefer using Google like free form query to do so. To facilitate free form query based …

Femtosecond Photoelectron Point Projection Microscope, Erik Quinonez, Jonathan Handali, Brett Barwick

Faculty Scholarship

By utilizing a nanometer ultrafast electron source in a point projection microscope we demonstrate that images of nanoparticles with spatial resolutions of the order of 100 nanometers can be obtained. The duration of the emission process of the photoemitted electrons used to make images is shown to be of the order of 100 fs using an autocorrelation technique. The compact geometry of this photoelectron point projection microscope does not preclude its use as a simple ultrafast electron microscope, and we use simple analytic models to estimate temporal resolutions that can be expected when using it as a pump-probe ultrafast electron …

Scene Understanding For Real Time Processing Of Queries Over Big Data Streaming Video, Alexander Aved

Electronic Theses and Dissertations

With heightened security concerns across the globe and the increasing need to monitor, preserve and protect infrastructure and public spaces to ensure proper operation, quality assurance and safety, numerous video cameras have been deployed. Accordingly, they also need to be monitored effectively and efficiently. However, relying on human operators to constantly monitor all the video streams is not scalable or cost effective. Humans can become subjective, fatigued, even exhibit bias and it is difficult to maintain high levels of vigilance when capturing, searching and recognizing events that occur infrequently or in isolation. These limitations are addressed in the Live Video …

Discriminative Dictionary Learning With Spatial Constraints, Muhammad Nazar Khan

Electronic Theses and Dissertations

In this thesis, we investigate the use of dictionary learning for discriminative tasks on natural images. Our contributions can be summarized as follows: • We introduce discriminative deviation based learning to achieve principled handling of the reconstruction-discrimination tradeoff that is inherent to discriminative dictionary learning. • Since natural images obey a strong smoothness prior, we show how spatial smoothness constraints can be incorporated into the learning formulation by embedding dictionary learning into Conditional Random Field (CRF) learning. We demonstrate that such smoothness constraints can lead to state-of-the-art performance for pixel-classification tasks. • Finally, we lay down the foundations of super-latent …

Automatically Acquiring A Semantic Network Of Related Concepts, Sean Szumlanski

Electronic Theses and Dissertations

We describe the automatic acquisition of a semantic network in which over 7,500 of the most frequently occurring nouns in the English language are linked to their semantically related concepts in the WordNet noun ontology. Relatedness between nouns is discovered automatically from lexical co-occurrence in Wikipedia texts using a novel adaptation of an information theoretic inspired measure. Our algorithm then capitalizes on salient sense clustering among these semantic associates to automatically disambiguate them to their corresponding WordNet noun senses (i.e., concepts). The resultant concept-to-concept associations, stemming from 7,593 target nouns, with 17,104 distinct senses among them, constitute a large-scale semantic …

Detecting Semantic Method Clones In Java Code Using Method Ioe-Behavior, Rochelle Elva

Electronic Theses and Dissertations

The determination of semantic equivalence is an undecidable problem; however, this dissertation shows that a reasonable approximation can be obtained using a combination of static and dynamic analysis. This study investigates the detection of functional duplicates, referred to as semantic method clones (SMCs), in Java code. My algorithm extends the input-output notion of observable behavior, used in related work [1, 2], to include the effects of the method. The latter property refers to the persistent changes to the heap, brought about by the execution of the method. To differentiate this from the typical input-output behavior used by other researchers, I …

Optimization Of Energy Resolution In The Digital Hadron Calorimeter Using Longitudinal Weights, Jacob Russell Smith

Physics Dissertations

Particle physics seeks to describe matter in its most elementary structure. With lepton colliders; couplings of gauge bosons and heavy quarks, physics beyond the Standard Model, and properties of a recently discovered Higgs boson can be studied with very high precision. Particle Flow Algorithms (PFA), able to achieve necessary jet-energy and di-jet mass resolutions, require fine transverse and longitudinal segmentation from calorimeters. To validate digital imaging calorimetry in this context, a Digital Hadron Calorimeter (DHCAL) with single-bit (digital) readout on imbedded electronics from 1×1 cm2 pads throughout its volume has been constructed and exposed to particle beams as a large …

Atomic And Molecular Adsorptions Of Hydrogen And Oxygen On Silicon Nanotubes: An Ab Initio Study, Haoliang Chen

Physics Dissertations

A systematic ab initio study of silicon nanotubes (SiNTs) in single-walled, double-walled armchair and zigzag configurations will be presented. Electronic and structural properties of all these nanostructures have been calculated using hybrid density functional B3LYP and 3-21G* basis set as implemented in the GAUSSIAN 03/09 suite of software. The binding energy increases as diameter of the nanotube increases generally for both armchair and zigzag SiNTs. The HOMO-LUMO gaps of the armchair and zigzag SiNTs are in the range from 0.20 to 1.81 eV and do not show any metallic behavior. Radial buckling calculations indicate that the armchair SiNTs all have …

Palynology Of Acid-Saline Lakes Of Western Australiabiostratigraphy And Paleoenvironmental Reconstruction, Carlos A. Sanchez Botero

Doctoral Dissertations

"Lakes are excellent repositories of fossils and sedimentary features that provide clues to past climatic and geologic events. Sediments from four cores drilled in Lake Aerodrome (LA1-09, LA2-09) and Lake Brown (LB1-09, LB2-09), two of the hundreds of ephemeral lakes in southern Western Australia, were analyzed for their palynological contents to understand the geologic and climatic evolution of the depositional basin. Palynofacies assemblages defined by statistical analyses of dispersed organic matter suggested differences in the depositional conditions and probable correlations between Lake Aerodrome cores. Detailed identifications and quantification of organic-walled microfossils yielded two palynomorph assemblages that reflect a climatic turnover: …

A 2,500-Year Record Of Environmental Change In Highlands Hammock State Park (Central Florida, U.S.A.) Inferred From Siliceous Microfossils, Christof Pearce, Holger Cremer, Emmy Lammertsma, Friederike Wagner-Cremer

FCE LTER Journal Articles

Analysis of siliceous microfossils of a 79 cm long peat sediment core from Highlands Hammock State Park, Florida, revealed distinct changes in the local hydrology during the past 2,500 years. The coring site is a seasonally inundated forest where water availability is directly influenced by precipitation. Diatoms, chrysophyte statospores, sponge remains and phytoliths were counted in 25 samples throughout the core. Based on the relative abundance of diatom species, the record was subdivided into four diatom assemblage zones, which mainly reflect the hydrological state of the study site. An age-depth relationship based on radiocarbon measurements of eight samples reveals a …

Summertime Influences Of Tidal Energy Advection On The Surface Energy Balance In A Mangrove Forest, Jordan G. Barr, J. D. Fuentes, M. S. Delonge, T. L. O'Halloran, J. C. Zeiman

FCE LTER Journal Articles

Mangrove forests are ecosystems susceptible to changing water levels and temperatures due to climate change as well as perturbations resulting from tropical storms. Numerical models can be used to project mangrove forest responses to regional and global environmental changes, and the reliability of these models depends on surface energy balance closure. However, for tidal ecosystems, the surface energy balance is complex because the energy transport associated with tidal activity remains poorly understood. This study aimed to quantify impacts of tidal flows on energy dynamics within a mangrove ecosystem. To address the research objective, an intensive 10-day study was conducted in …

Mechanisms Of Bicarbonate Use Influence The Photosynthetic Carbon Dioxide Sensitivity Of Tropical Seagrasses, Justin E. Campbell, James W. Fourqurean

FCE LTER Journal Articles

The photosynthetic bicarbonate () use properties of three widely distributed tropical seagrasses were compared using a series of laboratory experiments. Photosynthetic rates of Thalassia testudinum, Halodule wrightii, and Syringodium filiforme were monitored in an enclosed chamber while being subjected to shifts in pH and dissolved inorganic carbon. Specific mechanisms of seagrass use were compared by examining the photosynthetic effects of the carbonic anhydrase inhibitor acetazolamide (AZ). All seagrasses increased photosynthetic rates with reduced pH, suggesting a large effect of dissolved aqueous carbon dioxide (CO_2(aq)). However, there was considerable interspecific variation in pH response. T. testudinum was …

Semiclassical Partition Functions For Gravity With Cosmic Strings, Christopher L. Duston

Physics Faculty Publications

In this paper we describe an approach to construct semiclassical partition functions in gravity which are complete in the sense that they contain a complete description of the differentiable structures of the underlying 4-manifold. In addition, we find our construction naturally includes cosmic strings. We prove that the mass density of these strings uniquely specifies the topology of the leaves of a dimension 2 foliation, and conjecture that spacetime topology emerges as a result of the symmetry breaking of the fundamental fields. We discuss some possible applications of the partition functions in the fields of both quantum gravity and topological …

Water Quality Monitoring Program For Bermuda's Coastal Resources Final Report, Henry O. Briceño, Joseph N. Boyer

SERC Research Reports

No abstract provided.

Do Non-Response Follow-Ups Improve Or Reduce Data Quality?: A Review Of The Existing Literature, Kristen Olson

Department of Sociology: Faculty Publications

The paper systematically reviews existing literature on the relationship between the level of effort to recruit a sampled person and the measurement quality of survey data. Hypotheses proposed for this relationship are reviewed. Empirical findings for the relationship between level of effort as measured by paradata (the number of follow-up attempts, refusal conversion and time in the field) and question-specific item non-response rates, aggregate measures of item non-response rates, response accuracy and various measurement errors on attitudinal questions are examined through a qualitative review.