Doctoral Dissertations

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    Data-driven deep Neural Networks for epidemiological and biochemical models
    (Middle Tennessee State University, 2022) Olumoyin, Kayode Daniel ; Khaliq, Abdul Q.M. ; Ding, Wandi ; Robertson, William ; Stephens, Chris
    In recent years, the efficiency of deep neural networks to forward and inverse problems that have found applications in biochemical and epidemiological models has been demonstrated. In these systems, it has been observed that the system parameters fit unknown nonlinear functions. Classical models mostly assume these system parameters to be constants. Some researchers explicitly chose a form for these nonlinear parameters using intuition and good reasoning. In this work, we will study mathematical models with nonlinear dynamics that occur in biochemical and epidemiological models and we will develop data-driven deep learning approaches to learn the nonlinear parameters in these models and thereby detect hidden patterns in these complex systems. In our study, we will employ a modification of the physics-informed neural network. The modified network, which we call an epidemiology informed neural network, allows us to predict nonlinear system parameters. Here, multilayer perceptrons are connected to a larger multilayer perceptron that learns the solution to a system of partial differential equations or a system of ordinary differential equations. The Neural network approaches we present are suitable for partial differential equations and ordinary differential equations because they are meshless and can scale to high spatial dimensions. They can also solve forward and inverse problems with sparse data. We enforce the physics of our model in the objective function and device efficient methods that allows us to train with a small dataset. The adaptive neuro-fuzzy inference system, a widely used Neural network in time series forecast, is combined with an epidemiology informed neural network. We demonstrate that this hybrid network is an improvement over the adaptive neuro-fuzzy inference system. We also demonstrate that the epidemiology informed neural network combined with a recurrent neural network such as the long short-term memory network provides a more accurate short-term forecast than a plain recurrent neural network. Next, we develop an attention-based neural network that is capable of learning nonlinear dynamics from noisy data.
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    The complementary relationship between concerts and recorded music for top-performing artists
    (Middle Tennessee State University, 2022) Hogue, Eric Daniel ; Roach, Michael ; Gamble, Keith ; Rennhoff, Adam
    Paper 1: Promotional effects of recorded music and superstars on concert financial outcomes Using a comprehensive data set of hand-collected observations of top touring performing artists, I examine the relationship between recorded music and concert financial outcomes. I find that music streaming derives substantive financial benefit to the top-100 touring artists. Using empirical estimates from a panel model with artist fixed-effects, an artist can derive an incremental $46K to $49K per show when achieving a 20% increase in music streaming. Additionally, using a 2SLS model with artist fixed-effects to account for potential endogenous promotional effects, I identify top performers ("superstars") who derive significant additional concert revenue because of their back-catalog of hit songs. These top performers earn an incremental $15K per show in response to every week they have a song from their catalog in the Billboard Top-20. These findings indicate that artists maintain the ability to use their musical and performance legacy to build lifelong earnings from their music and performance. Paper 2: The complementary relationship between concerts and recorded music for top-performing artists This paper examines the complementary effects of live concerts on incremental pre-and-post concert music streams in twenty-nine US cities. The work identifies that performers who have greater concert ticket demand, deeper hit-song catalogs, and/or are in the middle of their career experience stronger trends in their streams before and after their concerts in the markets where they perform. It also identifies that post-concert effects last up to ten weeks after the event. I hand-collected data of concert ticket sales, music streaming, and song rankings from the top sixty global performing artists. I then utilized a panel model empirical approach with artist and market fixed-effects to identify pre-concert promotional and post-concert decaying effects. This work will help top performing artists gain insight into the little-understood influence of live performance on the streaming of their recorded music. Paper 3: Performing artist response to the Copyright Royalty Board rate increase and the Music Modernization Act This paper examines the financial impact of the consecutive regulatory events of the Copyright Royalty Board rate increase in January 2018 and the passage of the Music Modernization Act in October 2018 on the release activity by the top 100 artists. This work identifies that the rate increase corresponded with a significant increase in musical track releases for a short eight-month period until the Music Modernization Act became law. Artists who are younger, had composed their music, and/or actively touring were more likely to increase their release activity. The analysis also identifies a handful of artists who have benefited from the new regulations.
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    Teacher Perceptions of the Supports and Barriers of Teacher Collaboration
    (Middle Tennessee State University, 2022) Wendel, Meredith ; Krahenbuhl, Kevin ; Korstange, Ryan ; Hooser, Angela ; Carter, Lando ; Dillard, Heather
    ABSTRACT When teachers collaborate, they amass collective expertise and develop pedagogical content knowledge. Teacher collaboration is often a school priority because of its positive impact on student achievement, teacher efficacy, and teacher satisfaction. Schools also have complex systems in place that impact the effectiveness of teacher collaboration. This study explores six teachers’ perceptions of their collaboration with peers and how it is supported or weakened by the organization of school structures, the leadership system, and the evaluation system implemented at their school. Three school sites were purposefully chosen for their expectation that teachers engage in collaboration and their different approaches to organizing time for teacher collaboration. One school allocated ninety minutes of daily non-instructional time plus ninety extra minutes one day per week for teacher collaboration. The second school follows the PLC guidelines set by Dufour and colleagues (2016) and allocates fifty minutes of daily non-instructional time and an additional sixty minutes per week specifically for content area PLCs to occur. The third school allots fifty-five minutes for non-instructional time and has no additional time set aside during the week. Two teachers at each school were interviewed using Seidman’s (2013) guidelines for conducting phenomenological interviews. The teachers revealed that the organizational structures and leadership of their schools had a greater impact than their yearly evaluations, which they saw as having little to no impact on their collaboration with other teachers. The teachers cited trust, particularly relational trust developed with their colleagues and the trust from their leadership, as a major support to the success of their collaboration. Time and the resistance towards collaboration from other teachers were seen as the biggest barriers to effectively collaborating with one’s peers.
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    The Cult of Cinderella: A Perennial Princess in Fourth-Wave Feminist America
    (Middle Tennessee State University, 2022) Bernier, Clarisse Scarlett ; Hixon, Martha ; Brantley, Will ; Holtzclaw, Robert
    Cinderella can either be considered a beloved staple of film, fairy tales, and childhood or a character whose portrayal as a persecuted heroine makes her a keen target for feminist critique. Her continuous presence on screen and in print attests to her popularity, yet many new versions of “Cinderella” draw ire as the character is typically depicted in need of a (male) savior. Current trends are shifting Cinderella away from this damsel-in-distress role, ensuring her relevancy to modern audiences. This dissertation examines Cinderella through a feminist lens and explains her permanent placement in feminist discourse and popular culture. Chapter One examines the history and evolution of “Cinderella” and variants of the Cinderella-tale as defined by Marian Roalfe Cox and classified by the Aarne-Thompson-Uther tale type index. This chapter scrutinizes the best-known variants of “Cinderella,” as written by Giambattista Basile, Charles Perrault, and the Brothers Grimm and discusses how the popularity of these three tales helped cement Cinderella’s continued relevance in both academic study and popular culture. Chapter Two examines feminist criticism of “Cinderella” and explores the shifts in that criticism through the second, third, and fourth waves of this movement. The changing focus of feminist critique towards this tale is reflected in modern retellings, which present a heroine with more depth and greater agency. Chapter Three examines these modern retellings, focusing on trends which shape the new “Cinderella,” presenting the tale through the lens of gender inclusivity, sex positivity and young adult expectations. This chapter also follows a trend which presents the tale from the perspective of previously supporting characters, such as the stepmother or the prince. Chapter Four follows Cinderella’s representation in film over the past seventy years, both as retellings which are true to the traditional fairy tale version or as retellings which present a Cinderella-story. Several films are examined through the lens of feminist criticism in an attempt to determine if that criticism has an effect on how Cinderella is presented in future adaptations. Chapter Five discusses the effect that Walt Disney’s Cinderella has had on how Americans view Cinderella, how this character has been monetized, and how she launched the idea of happily-ever-after, via a Disney wedding. This chapter examines feminist criticism which claims that viewing this film or engaging with Cinderella through games or make-believe will foster gendered behavior in children. Chapter Six discusses Cinderella’s relevance in popular culture, focusing on digital platforms which allow both academics and non-academics to offer defense or vitriol towards this princess. The continued relevance of Cinderella is demonstrated through her presentation in various pop culture formats, which offer the tale with changes that reflect current social ideology and shifts in feminist thinking.
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    Essays On the Impact of Competition Policies in the United States
    (Middle Tennessee State University, 2022) Bakuli, James ; Roach, Michael ; Roach, Michael ; Rennhoff, Adam ; Eff, Anthon
    The research topics of my dissertation focus on studying the impact of three competition policies in the United States – used car lemon laws, Apple’s alternative iPhone financing policy, and net neutrality rules. The results of my research work in this regard have aimed to contribute to the existing body of knowledge in these areas. I found evidence that, the implementation of the alternative payment plan induced competition in the wireless communication industry and resulted in a reduction in average plan price – the carrier’s average revenue per user fell by 5.9%. Also, my results reveal that the absence of net neutrality leads to a decrease in both maximum and average download speeds of 39.5 and 68.14, respectively, and increases average monthly charge by $9.53. A decrease in download speed (quality) contradicts the argument that the absence of net neutrality will incentivize ISPs to increase investment which will intend improve the quality of internet service to the end-users. Lastly, my results affirm the theoretical assertion of warranty provision as a remedy to information asymmetry in a secondary market. I found evidence that warranty provision, by reducing transaction cost, positively influence demand for used cars in the United States.