Advancements In Gaussian Process Learning For Uncertainty Quantification, 2022 Clemson University

#### Advancements In Gaussian Process Learning For Uncertainty Quantification, John C. Nicholson

*All Dissertations*

Gaussian processes are among the most useful tools in modeling continuous processes in machine learning and statistics. The research presented provides advancements in uncertainty quantification using Gaussian processes from two distinct perspectives. The first provides a more fundamental means of constructing Gaussian processes which take on arbitrary linear operator constraints in much more general framework than its predecessors, and the other from the perspective of calibration of state-aware parameters in computer models. If the value of a process is known at a finite collection of points, one may use Gaussian processes to construct a surface which interpolates these values to …

Data And Algorithmic Modeling Approaches To Count Data, 2022 Murray State University

#### Data And Algorithmic Modeling Approaches To Count Data, Andraya Hack

*Honors College Theses*

Various techniques are used to create predictions based on count data. This type of data takes the form of a non-negative integers such as the number of claims an insurance policy holder may make. These predictions can allow people to prepare for likely outcomes. Thus, it is important to know how accurate the predictions are. Traditional statistical approaches for predicting count data include Poisson regression as well as negative binomial regression. Both methods also have a zero-inflated version that can be used when the data has an overabundance of zeros. Another procedure is to use computer algorithms, also known as …

Mathematical Analysis Of An Sir Disease Model With Non-Constant Transmission Rate, 2022 Southwestern Oklahoma State University

#### Mathematical Analysis Of An Sir Disease Model With Non-Constant Transmission Rate, Emma Bollinger, Tayler Valdez, Swarup Ghosh, Sunil Giri

*Student Research*

- Epidemiology: A branch of medicine that studies causes, transmission, and control methods of diseases at the population level.
- Mathematical epidemiology deals with creating a model for a disease through the study of incidence and distribution of the disease throughout a population.
- Here, we have examined the behavior of a measles-like disease[2] that is characterized by a non-constant transmission rate.

Vertical Take-Off And Landing Control Via Dual-Quaternions And Sliding Mode, 2022 Embry-Riddle Aeronautical University

#### Vertical Take-Off And Landing Control Via Dual-Quaternions And Sliding Mode, Joshua Sonderegger

*Doctoral Dissertations and Master's Theses*

The landing and reusability of space vehicles is one of the driving forces into renewed interest in space utilization. For missions to planetary surfaces, this soft landing has been most commonly accomplished with parachutes. However, in spite of their simplicity, they are susceptible to parachute drift. This parachute drift makes it very difficult to predict where the vehicle will land, especially in a dense and windy atmosphere such as Earth. Instead, recent focus has been put into developing a powered landing through gimbaled thrust. This gimbaled thrust output is dependent on robust path planning and controls algorithms. Being able to …

Quadratic Neural Network Architecture As Evaluated Relative To Conventional Neural Network Architecture, 2022 University of South Carolina

#### Quadratic Neural Network Architecture As Evaluated Relative To Conventional Neural Network Architecture, Reid Taylor

*Senior Theses*

Current work in the field of deep learning and neural networks revolves around several variations of the same mathematical model for associative learning. These variations, while significant and exceptionally applicable in the real world, fail to push the limits of modern computational prowess. This research does just that: by leveraging high order tensors in place of 2nd order tensors, quadratic neural networks can be developed and can allow for substantially more complex machine learning models which allow for self-interactions of collected and analyzed data. This research shows the theorization and development of mathematical model necessary for such an idea to …

On Efficacy And Effectiveness Of Vaccines: A Mathematical Approach Based On Conditional Probability With Applications To The Covid-19 Context, 2022 Dortmund University of Applied Sciences and Arts

#### On Efficacy And Effectiveness Of Vaccines: A Mathematical Approach Based On Conditional Probability With Applications To The Covid-19 Context, Flavius Guias

*Spora: A Journal of Biomathematics*

This paper presents a mathematically formalized approach which points out the relation between efficacy and effectiveness of vaccines. The first term denotes the relative degree of protection in clinical trials or under ideal conditions, while the latter is based on observed real-life data. We define the efficacy by a similar formula to the effectiveness, but the probabilities involved in the relative risk are conditional with respect to the exposure to the virus. If exposure and vaccination status are independent, the two quantities are equal. Otherwise, the observed value of the effectiveness is a biased one, as it could be seen …

Existence And Uniqueness Of Minimizers For A Nonlocal Variational Problem, 2022 University of Nebraska - Lincoln

#### Existence And Uniqueness Of Minimizers For A Nonlocal Variational Problem, Michael Pieper

*Honors Theses*

Nonlocal modeling is a rapidly growing field, with a vast array of applications and connections to questions in pure math. One goal of this work is to present an approachable introduction to the field and an invitation to the reader to explore it more deeply. In particular, we explore connections between nonlocal operators and classical problems in the calculus of variations. Using a well-known approach, known simply as The Direct Method, we establish well-posedness for a class of variational problems involving a nonlocal first-order differential operator. Some simple numerical experiments demonstrate the behavior of these problems for specific choices of …

An Axiomatic And Contextual Review Of The Armitage And Doll Model Of Carcinogenesis, 2022 Western Carolina University

#### An Axiomatic And Contextual Review Of The Armitage And Doll Model Of Carcinogenesis, W. Zane Billings, Justin Clifton, Josh Hiller, Tommy Meek, Andrew Penland, Wesley Rogers, Gabriella Smokovich, Andrew Velasquez-Berroteran, Eleni Zamagias

*Spora: A Journal of Biomathematics*

In 1954, Armitage and Doll published one of the most influential papers in the history of mathematical epidemiology. However, when one examines the literature one finds that there are in fact at least three distinct mathematical models attributed to the 1954 paper. In this study, we examine this important paper and the mathematical derivation of their model. We find, very surprisingly, that no stochastic process can account for all the assumptions of the model and that many of the models in the literature use a consistent subset of the assumptions used in Armitage and Doll's paper.

Strengthening A Linear Reformulation Of The 0-1 Cubic Knapsack Problem Via Variable Reordering, 2022 Dickinson College

#### Strengthening A Linear Reformulation Of The 0-1 Cubic Knapsack Problem Via Variable Reordering, Richard Forrester, Lucas Waddell

*Faculty Journal Articles*

The 0-1 cubic knapsack problem (CKP), a generalization of the classical 0-1 quadratic knapsack problem, is an extremely challenging NP-hard combinatorial optimization problem. An effective exact solution strategy for the CKP is to reformulate the nonlinear problem into an equivalent linear form that can then be solved using a standard mixed-integer programming solver. We consider a classical linearization method and propose a variant of a more recent technique for linearizing 0-1 cubic programs applied to the CKP. Using a variable reordering strategy, we show how to improve the strength of the linear programming relaxation of our proposed reformulation, which ultimately …

Optimizing Pension Outcomes Using Target Volatility Investment Concept, 2022 Bentley University

#### Optimizing Pension Outcomes Using Target Volatility Investment Concept, Zefeng Bai

*2022*

The target volatility strategy is a very popular investment concept in financial marketplace. For my dissertation, I focus on studying the target volatility investment concept in application to pension accumulation as well as decumulation stages. Additionally, I extend a basic target volatility strategy by introducing trading boundaries to its asset allocation mechanism. My dissertation study follows a three-paper format.

In paper one, we propose a new pension strategy that aims at improving the protection of a long-term pension plan in volatile market conditions. Over a hypothetical twenty-year pension scheme, we show that our newly proposed strategy, which attaches a target …

An Exploration In Health Analytics: Pediatric Burns, Care Policy Assessment And Interrupted Time Series, 2022 Bentley University

#### An Exploration In Health Analytics: Pediatric Burns, Care Policy Assessment And Interrupted Time Series, Chao Wang

*2022*

Healthcare systems globally face multiple challenges in the face of population growth and changes in disease pathology. With regard to the rising demand of the healthcare and the global threats of the pandemic, the medical datasets can be trained further to develop preventive methods. Meanwhile, policy reforms of health systems could be a critical aspect to deal with the public crisis and concerns. However, two basic problems must be addressed first: identification of key factors on a priority basis and evaluation of changes.

Thus, the paper presents a series of trials on the application of data analytics to health-related problems, …

Mathematical Models Of Infection Prevention Programs In Hospital Settings, 2022 Virginia Commonwealth University

#### Mathematical Models Of Infection Prevention Programs In Hospital Settings, Kelly A. Reagan

*Theses and Dissertations*

Hospitals play a vital role in providing for the healthcare needs of a community. Patients can develop hospital-acquired infections (HAIs) during their hospitalization due to exposure to foreign bacteria, viruses, and fungi. Infection prevention programs target and reduce HAIs, but implementing the infection prevention programs often comes with a cost. The goal of my research is to use mathematical models to quantify the impact of infection prevention programs on cases of HAIs and total healthcare costs. First, I use a Markov chain model to quantify how one infection prevention program reduces general HAIs in the hospital. Then, I calculate the …

Sensitivity Analysis Of Basins Of Attraction For Gradient-Based Optimization Methods, 2022 Bowdoin College

#### Sensitivity Analysis Of Basins Of Attraction For Gradient-Based Optimization Methods, Gillian King

*Honors Projects*

This project is an analysis of the effectiveness of five distinct optimization methods in their ability in producing clear images of the basins of attraction, which is the set of initial points that approach the same minimum for a given function. Basin images are similar to contour plots, except that they depict the distinct regions of points--in unique colors--that approach the same minimum. Though distinct in goal, contour plots are useful to basin research in that idealized basin images can be inferred from the steepness levels and location of extrema they depict. Effectiveness of the method changes slightly depending on …

Sensitivity Analysis Of Basins Of Attraction For Nelder-Mead, 2022 Bowdoin College

#### Sensitivity Analysis Of Basins Of Attraction For Nelder-Mead, Sonia K. Shah

*Honors Projects*

The Nelder-Mead optimization method is a numerical method used to find the minimum of an objective function in a multidimensional space. In this paper, we use this method to study functions - specifically functions with three-dimensional graphs - and create images of the basin of attraction of the function. Three different methods are used to create these images named the systematic point method, randomized centroid method, and systemized centroid method. This paper applies these methods to different functions. The first function has two minima with an equivalent function value. The second function has one global minimum and one local minimum. …

Correlation Does Not Imply Correlation: A Thesis On Causal Influence And Simpson’S Paradox, 2022 Claremont Colleges

#### Correlation Does Not Imply Correlation: A Thesis On Causal Influence And Simpson’S Paradox, Emily Naitoh

*Scripps Senior Theses*

In our data-driven world, it has become commonplace to attempt to find

causal relationships. One of the themes of this thesis is to show methods of

determining causation. The second theme follows a saying in mathematics,

"correlation does not imply causation". We will also discuss situations where

correlation does not even imply correlation itself. These cases are described

by Simpson’s paradox in an exploration of different areas of mathematics

and computer coding.

Empirical Comparison Of Machine Learning Methods For Wind Power Predictions, 2022 Eastern Washington University

#### Empirical Comparison Of Machine Learning Methods For Wind Power Predictions, Sidny M. Stewart

*EWU Masters Thesis Collection*

No abstract provided.

An Exploration Of Voting With Partial Orders, 2022 Harvey Mudd College

#### An Exploration Of Voting With Partial Orders, Mason Acevedo

*HMC Senior Theses*

In this thesis, we discuss existing ideas and voting systems in social choice theory. Specifically, we focus on the Kemeny rule and the Borda count. Then, we begin trying to understand generalizations of these voting systems in a setting where voters can submit partial rankings on their ballot, instead of complete rankings.

Dynamic Nonlinear Gaussian Model For Inferring A Graph Structure On Time Series, 2022 Claremont Colleges

#### Dynamic Nonlinear Gaussian Model For Inferring A Graph Structure On Time Series, Abhinuv Uppal

*CMC Senior Theses*

In many applications of graph analytics, the optimal graph construction is not always straightforward. I propose a novel algorithm to dynamically infer a graph structure on multiple time series by first imposing a state evolution equation on the graph and deriving the necessary equations to convert it into a maximum likelihood optimization problem. The state evolution equation guarantees that edge weights contain predictive power by construction. After running experiments on simulated data, it appears the required optimization is likely non-convex and does not generally produce results significantly better than randomly tweaking parameters, so it is not feasible to use in …

Role Of Inhibition And Spiking Variability In Ortho- And Retronasal Olfactory Processing, 2022 Virginia Commonwealth University

#### Role Of Inhibition And Spiking Variability In Ortho- And Retronasal Olfactory Processing, Michelle F. Craft

*Theses and Dissertations*

Odor perception is the impetus for important animal behaviors, most pertinently for feeding, but also for mating and communication. There are two predominate modes of odor processing: odors pass through the front of nose (**ortho**) while inhaling and sniffing, or through the rear (**retro**) during exhalation and while eating and drinking. Despite the importance of olfaction for an animal’s well-being and specifically that ortho and retro naturally occur, it is unknown whether the modality (ortho versus retro) is transmitted to cortical brain regions, which could significantly instruct how odors are processed. Prior imaging studies show different …

Containing Compounding Container Congestion, 2022 Claremont Colleges

#### Containing Compounding Container Congestion, Curtis Salinger

*CMC Senior Theses*

The Covid-19 pandemic caused major disruptions throughout the container shipping supply chain. Professor Dongping Song of Liverpool University wrote a paper discussing the logistical vulnerabilities in the supply chain, including the issue of congestion in ports. This paper examines the Port of Los Angeles from 2018-2021 as it relates to Song’s paper to see how its operations were impacted during the Covid-19 timeframe. It is found that labor shortages, chassis shortages, and change in trade behavior each contributed to the congestion. Unfortunately, the implemented policies were insufficient to bolster the port against sustained challenges and congestion continues to worsen.