Modeling The Release And Spreading Of Permanganate From Aerated Slow-Release Oxidants In A Laboratory Flow Tank, 2021 University of Nebraska-Lincoln

#### Modeling The Release And Spreading Of Permanganate From Aerated Slow-Release Oxidants In A Laboratory Flow Tank, Ann Kambhu, Yusong Li, Troy E. Gilmore, Steve D. Comfort

*Papers in Natural Resources*

Aerated, slow-release oxidants are a relatively new technology for treating contaminated aquifers. A critical need for advancing this technology is developing a reliable method for predicting the radius of influence (ROI) around each drive point. In this work, we report a series of laboratory flow tank experiments and numerical modeling efforts designed to predict the release and spreading of permanganate from aerated oxidant candles (oxidant-wax composites). To mimic the design of the oxidant delivery system used in the field, a double screen was used in a series of flow tank experiments where the oxidant was placed inside the inner screen ...

Self-Exciting Point Process For Modelling Terror Attack Data, 2021 Wilfrid Laurier University

#### Self-Exciting Point Process For Modelling Terror Attack Data, Siyi Wang

*Theses and Dissertations (Comprehensive)*

Terrorism becomes more rampant in recent years because of separatism and extreme nationalism, which brings a serious threat to the national security of many countries in the world. The analysis of spatial and temporal patterns of terror data is significant in containing terrorism. This thesis focuses on building and applying a temporal point process called self-exciting point process to fit the terror data from 1970 to 2018 of 10 countries. The data come from the Global Terrorism database. Further, an application in predicting the number of terror events based on the self-exciting model is another main innovative idea, in which ...

Geometric Unified Method In 3d Object Classification, 2021 Claremont Colleges

#### Geometric Unified Method In 3d Object Classification, Mengyi Shan

*HMC Senior Theses*

3D object classification is one of the most popular topics in the field of computer vision and computational geometry. Currently, the most popular state-of-the-art algorithm is the so-called Convolutional Neural Network (CNN) models with various representations that capture different features of the given 3D data, including voxels, local features, multi-view 2D features, and so on. With CNN as a holistic approach, researches focus on improving the accuracy and efficiency by designing the neural network architecture. This thesis aims to examine the existing work on 3D object classification and explore the underlying theory by integrating geometric approaches. By using geometric algorithms ...

Radial Singular Solutions To Semilinear Partial Differential Equations, 2021 Claremont Colleges

#### Radial Singular Solutions To Semilinear Partial Differential Equations, Marcelo A. Almora Rios

*HMC Senior Theses*

We show the existence of countably many non-degenerate continua of singular radial solutions to a p-subcritical, p-Laplacian Dirichlet problem on the unit ball in R^N. This result generalizes those for the 2-Laplacian to any value p and extends recent work on the p-Laplacian by considering solutions both radial and singular.

Search For Gravitational Waves From Scorpius X-1 In The Second Advanced Ligo Observing Run With An Improved Hidden Markov Model, 2020 Andrews University

#### Search For Gravitational Waves From Scorpius X-1 In The Second Advanced Ligo Observing Run With An Improved Hidden Markov Model, Tiffany Summerscales, Ligo Scientific Collaboration And The Virgo Collaboration

*Faculty Publications*

We present results from a semicoherent search for continuous gravitational waves from the low-mass x-ray binary Scorpius X-1, using a hidden Markov model (HMM) to track spin wandering. This search improves on previous HMM-based searches of LIGO data by using an improved frequency domain matched filter, the J-statistic, and by analyzing data from Advanced LIGO’s second observing run. In the frequency range searched, from 60 to 650 Hz, we find no evidence of gravitational radiation. At 194.6 Hz, the most sensitive search frequency, we report an upper limit on gravitational wave strain (at 95% confidence) of h95%0 ...

An Enticing Study Of Prime Numbers Of The Shape ?? = ??^2 + ??^2, 2020 CUNY New York City College of Technology

#### An Enticing Study Of Prime Numbers Of The Shape ?? = ??^2 + ??^2, Xiaona Zhou

*Publications and Research*

We will study and prove important results on primes of the shape ??^{2} + ??^{2} using number theoretic techniques. Our analysis involves maps, actions over sets, fixed points and involutions. This presentation is readily accessible to an advanced undergraduate student and lay the groundwork for future studies.

A Near-Optimal Change-Detection Based Algorithm For Piecewise-Stationary Combinatorial Semi-Bandits, 2020 Singapore Management University

#### A Near-Optimal Change-Detection Based Algorithm For Piecewise-Stationary Combinatorial Semi-Bandits, Huozhi Zhou, Lingda Wang, Lav N. Varshney, Ee Peng Lim

*Research Collection School Of Information Systems*

We investigate the piecewise-stationary combinatorial semi-bandit problem. Compared to the original combinatorial semi-bandit problem, our setting assumes the reward distributions of base arms may change in a piecewise-stationary manner at unknown time steps. We propose an algorithm, GLR-CUCB, which incorporates an e?cient combinatorial semi-bandit algorithm, CUCB, with an almost parameter-free change-point detector, the Generalized Likelihood Ratio Test (GLRT). Our analysis shows that the regret of GLR-CUCB is upper bounded by O(√NKT logT), where N is the number of piecewise-stationary segments, K is the number of base arms, and T is the number of time steps. As a complement, we ...

Corn And Soybean Response To Wastewater-Recycled Phosphorus Fertilizers, 2020 University of Arkansas, Fayetteville

#### Corn And Soybean Response To Wastewater-Recycled Phosphorus Fertilizers, Shane Ylagan

*Crop, Soil and Environmental Sciences Undergraduate Honors Theses*

The ability to recycle phosphorus (P) from wastewaters could provide a sustainable, continuous source of P that might also help protect surface water quality from P enrichment. The mineral struvite (MgNH4PO4·6H2O) is an understudied material that can be created from Pcontaining wastewater and has been shown to have agricultural fertilizer value. The objective of this study was to evaluate the effects of electrochemically precipitated struvite (ECST), chemically precipitated struvite (Crystal Green; CG), diammonium phosphate (DAP), monoammonium phosphate (MAP), rock phosphate (RP), and triple super phosphate (TSP) on corn (Zea mays) and soybean (Glycine max) response in a 79-day greenhouse ...

Detecting Hacker Threats: Performance Of Word And Sentence Embedding Models In Identifying Hacker Communications, 2020 Technological University Dublin

#### Detecting Hacker Threats: Performance Of Word And Sentence Embedding Models In Identifying Hacker Communications, Susan Mckeever, Brian Keegan, Andrei Quieroz

*Conference papers*

Abstract—Cyber security is striving to find new forms of protection against hacker attacks. An emerging approach nowadays is the investigation of security-related messages exchanged on deep/dark web and even surface web channels. This approach can be supported by the use of supervised machine learning models and text mining techniques. In our work, we compare a variety of machine learning algorithms, text representations and dimension reduction approaches for the detection accuracies of software-vulnerability-related communications. Given the imbalanced nature of the three public datasets used, we investigate appropriate sampling approaches to boost detection accuracies of our models. In addition, we ...

Approximating Special Social Influence Maximization Problems, 2020 Rowan University

#### Approximating Special Social Influence Maximization Problems, Jie Wu, Ning Wang

*Faculty Scholarship for the College of Science & Mathematics*

Social Influence Maximization Problems (SIMPs) deal with selecting k seeds in a given Online Social Network (OSN) to maximize the number of eventually-influenced users. This is done by using these seeds based on a given set of influence probabilities among neighbors in the OSN. Although the SIMP has been proved to be NP-hard, it has both submodular (with a natural diminishing-return) and monotone (with an increasing influenced users through propagation) that make the problem suitable for approximation solutions. However, several special SIMPs cannot be modeled as submodular or monotone functions. In this paper, we look at several conditions under which ...

Deep Neural Network For Complex Open-Water Wetland Mapping Using High-Resolution Worldview-3 And Airborne Lidar Data, 2020 Iowa State University

#### Deep Neural Network For Complex Open-Water Wetland Mapping Using High-Resolution Worldview-3 And Airborne Lidar Data, Vitor S. Martins, Amy L. Kaleita, Brian K. Gelder, Gustavo W. Nagel, Daniel A. Maciel

*Agricultural and Biosystems Engineering Publications*

Wetland inventory maps are essential information for the conservation and management of natural wetland areas. The classification framework is crucial for successful mapping of complex wetlands, including the model selection, input variables and training procedures. In this context, deep neural network (DNN) is a powerful technique for remote sensing image classification, but this model application for wetland mapping has not been discussed in the previous literature, especially using commercial WorldView-3 data. This study developed a new framework for wetland mapping using DNN algorithm and WorldView-3 image in the Millrace Flats Wildlife Management Area, Iowa, USA. The study area has several ...

Teaching Applications And Implications Of Blockchain Via Project-Based Learning: A Case Study, 2020 Bryant University

#### Teaching Applications And Implications Of Blockchain Via Project-Based Learning: A Case Study, Kevin Mentzer, Mark Frydenberg, David J. Yates

*Computer Information Systems Journal Articles*

This paper presents student projects analyzing or using blockchain technologies, created by students enrolled in courses dedicated to teaching blockchain, at two different universities during the 2018-2019 academic year. Students explored perceptions related to storing private healthcare information on a blockchain, managing the security of Internet of Things devices, maintaining public governmental records, and creating smart contracts. The course designs, which were centered around project-based learning, include self-regulated learning and peer feedback as ways to improve student learning. Students either wrote a research paper or worked in teams on a programming project to build and deploy a blockchain-based application using ...

Embedded-Atom-Method Modeling Of Alkali-Metal/Transition-Metal Interfaces, 2020 Utah State University

#### Embedded-Atom-Method Modeling Of Alkali-Metal/Transition-Metal Interfaces, Jake D. Christensen

*All Graduate Theses and Dissertations*

Understanding the thermal properties of materials is essential to using those materials for technological advancement which can benefit civilization. For example, it has been proposed that essential components of tokamaks, devices which perform fusion, be made out of tungsten with a thin layer of lithium on the surface. To that end, this thesis seeks to calculate the thermal properties of a layer of alkali atoms, like lithium and sodium, on tungsten and molybdenum substrates. We use an Embedded Atom Method (EAM) model to perform our calculations. This type of model has been widely used to describe the interaction between atoms ...

The Development And Use Of A Secondary Electron Yield Database For Spacecraft Charge Modeling, 2020 Utah State University

#### The Development And Use Of A Secondary Electron Yield Database For Spacecraft Charge Modeling, Phillip Lundgreen

*All Graduate Theses and Dissertations*

Charge modeling of electron-solid interactions requires a detailed and accurate compilation of experimental data on which to base its physics and against which to test its predictions. Historically researchers used methods involving individual research or information taken from existing, vague, databases that were often found wanting. To streamline the charge modeling process, a collection of data has been assembled and categorized based upon surface morphology and contamination from various published sources and existing databases. The quality and quantity of the compilation vary widely with very little information offered with regards to surface conditions of various materials (contamination, morphology, etc. ...). Included ...

Exact Generalized Voronoi Diagram Computation Using A Sweepline Algorithm, 2020 Utah State University

#### Exact Generalized Voronoi Diagram Computation Using A Sweepline Algorithm, Daniel Marsden

*All Graduate Theses and Dissertations*

Voronoi Diagrams can provide useful spatial information. Little work has been done on computing exact Voronoi Diagrams when the sites are more complex than a point. We introduce a technique that measures the exact Generalized Voronoi Diagram from points, line segments and, connected lines including lines that connect to form simple polygons. Our technique is an extension of Fortune’s method. Our approach treats connected lines (or polygons) as a single site.

Sum Of Cubes Of The First N Integers, 2020 California State University, San Bernardino

#### Sum Of Cubes Of The First N Integers, Obiamaka L. Agu

*Electronic Theses, Projects, and Dissertations*

In Calculus we learned that ??Sum^{n}_{k=1} k = [n(n+1)]/2 , that Sum^{??n}_{k=1} k^2 = [n(n+1)(2n+1)]/6 , and that Sum^{n}_{k=1} k^{3} = (n(n+1)/2)^{2}. These formulas are useful when solving for the area below quadratic or cubic function over an interval [a, b]. This tedious process, solving for areas under a quadratic or a cubic, served as motivation for the introduction of Riemman integrals. For the overzealous math student, these steps were replaced by a simpler method of evaluating antiderivatives at ...

Environmental Controls On Didymosphenia Geminata Bloom Formation, 2020 Utah State University

#### Environmental Controls On Didymosphenia Geminata Bloom Formation, Lindsay Capito

*All Graduate Theses and Dissertations*

Climate change is causing rapid glacial recession and earlier snowmelt, which alter the physical and chemical properties of rivers. As a result, organisms at the base of the food web are responding in unforeseen ways. We use the nuisance algae D. geminata (Didymo) as a case study for how climate induced shifts in the timing of glacial and snowmelt runoff are affecting river ecosystems. We evaluated how shifts in the timing of nutrient concentrations and light availability affect nuisance blooms of Didymo in three complementary ways. These are, field studies across streams in various stages of glacial recession, weekly measurements ...

Delta Hedging Of Financial Options Using Reinforcement Learning And An Impossibility Hypothesis, 2020 Utah State University

#### Delta Hedging Of Financial Options Using Reinforcement Learning And An Impossibility Hypothesis, Ronak Tali

*All Graduate Theses and Dissertations*

In this thesis we take a fresh perspective on delta hedging of financial options as undertaken by market makers. The current industry standard of delta hedging relies on the famous Black Scholes formulation that prescribes continuous time hedging in a way that allows the market maker to remain risk neutral at all times. But the Black Scholes formulation is a deterministic model that comes with several strict assumptions such as zero transaction costs, log normal distribution of the underlying stock prices, etc. In this paper we employ Reinforcement Learning to redesign the delta hedging problem in way that allows us ...

Water, Fish, And Fire: Interdisciplinary Research On Ecosystem Services And Climate Adaptation, 2020 Utah State University

#### Water, Fish, And Fire: Interdisciplinary Research On Ecosystem Services And Climate Adaptation, Liana Prudencio

*All Graduate Theses and Dissertations*

Ecosystem services, or benefits from the environment, are plentiful and vary from place to place. Human activities and climate change have impacted these services in every region of the world. This dissertation explores multiple ecosystem services, from water quality improvement to provisioning of fish and habitat, in multiple and international contexts. The first chapter synthesizes the literature on stormwater management and ecosystem services, finding that research at this intersection has provided many parcel-level studies and frameworks for implementing green infrastructure. The second chapter extends the stormwater management literature by quantifying the impacts of green infrastructure on water quantity and quality ...

On Subdiagonal Rational Pade Approximations And The Brenner-Thomee Approximation Theorem For Operator Semigroups, 2020 Louisiana State Univ, Dept Math, Baton Rouge, LA

#### On Subdiagonal Rational Pade Approximations And The Brenner-Thomee Approximation Theorem For Operator Semigroups, Frank Neubrander, Koray Ozer, Lee Windsperger

*Faculty Publications*

The computational powers of Mathematica are used to prove polynomial identities that are essential to obtain growth estimates for subdiagonal rational Pade approximations of the exponential function and to obtain new estimates of the constants of the Brenner-Thomee Approximation Theorem of Semigroup Theory.