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Analysis of Polycyclic Aromatic Hydrocarbons in the Particulate Phase of Biomass Smoke by Mass Spectrometric Methods
No full textParticulate matter (PM) from wildfire smoke is a great health concern for firefighters, who rarely wear full protective breathing equipment. Some of the most concerning particulate matter toxicants are polycyclic aromatic hydrocarbons and heavy metals. Polycyclic aromatic hydrocarbons (PAHs) are a class of compounds created by the incomplete combustion of organic materials. They are known as mutagens, carcinogens and have been known to cause heart disease. Traditionally gas chromatography-mass spectrometry (GC-MS) has been used to quantify the levels of PAHs, but this tends to be labor-intensive and time-consuming. This study describes a novel method for the PAH analysis by direct analysis in real-time-mass spectrometry (DART-MS). The proposed DART-MS method allows for the quantification of both polar and non-polar PAHs quickly with no labor-intensive extraction. DART-MS can potentially serve as an alternative method for the detection of PAHs in wildfire smoke, with higher throughput. The analysis of heavy metals in PM by inductively coupled plasma - optical emission spectrometry (ICP-OES) has also been implemented in this study.M.S
Investigating the Relationship Between Workload and Officer-Involved Shootings of Unarmed Individuals
No full textThis study examines the relationship between officer workload and lethal, officer-involved shootings of unarmed individuals (LOIS-Us) that occurred in the United States between 2016 and 2018. The author created two indices of officer workload, total incident workload, and violent crime workload, using archival data. The indices were created for each state and municipality in which one or more LOIS-Us occurred. The author hypothesized that (1) states with more LOIS-Us would have higher workload indices than states with fewer LOIS-Us, and (2) both workload indices would be higher in municipalities where one or more LOIS-Us occurred than corresponding state-level indices. Unexpectedly, total incident workload was unrelated to LOIS-Us and violent crime workload was negatively correlated with LOIS-Us. Average state workload values were higher than the values in studied municipalities. Future research should explore whether these findings stem from officers with lower workloads having less experience responding to crimes
APPLICATIONS OF MODERN NLP TECHNIQUES FOR PREDICTIVE MODELING IN ACTUARIAL SCIENCE
No full textIn this dissertation, the research focuses on Natural Language Processing (NLP)
applications in actuarial science. NLP techniques, as powerful text analytic tools,
can automatically help actuaries to exploit the information in textual data. Recently,
many NLP techniques have been applied in different research fields, but
only a few NLP applications can be found in actuarial science. This dissertation
researches NLP techniques in actuarial science and proposes some NLP solutions
for actuarial applications.
This dissertation consists of five chapters. The first chapter is an introduction
of NLP and some opportunities for its use in actuarial science. The possibilities
of traditional actuarial applications incorporating NLP are also discussed. A few
NLP applications proposed by actuaries are also introduced as references.
The second chapter is the literature review of relevant NLP techniques. Some
basic technologies are introduced such as word embeddings and tokenizations.
Also, advanced NLP tools such as Bidirectional Encoder Representation for Transformers
(BERT) and related techniques are discussed.
The third chapter is an NLP application based on extended truck warranty
data. This chapter develops a BERT-based aggregate loss model with a rescaled
10-value scale severity to predict future losses based on the frequency distribution
of claim counts with contracts and severity distribution of claim records. The NLP
tool helps to extract information from the textual description in the data, and the
extracted values are exploited to predict loss severity.
The fourth chapter is another NPL application for basic truck warranty data.
A data-based portfolio allocation model is proposed to predict losses using the
modern portfolio theory (MPT) developed by Nobel Laureate Harry Markowitz
in 1952. In this chapter, BERT is applied to improve the accuracy of multi-class
classification in the BERT enhanced data-based portfolio allocation model. Also,
a technique similar to the one used in chapter 3 is applied to derive a BERTbased
severity model for multi-class aggregate loss prediction through a different
approach with the BERT enhanced data-based portfolio allocation model.
The last chapter summarizes the described applications. The applications of
modern NLP techniques for predictive analytics are practical and promising. However,
applications to actuarial science are almost nonexistent. This dissertation
demonstrates the possibilities of NLP applications to improve predictive modeling
in actuarial science. The NLP techniques can help to gather information from
textual descriptions discarded by traditional models. The possible improvements
that can be made in future research are also described in this chapter.Ph.D
NUMERICAL ALGORITHMS FOR FRACTIONAL PARTIAL DIFFERENTIAL EQUATIONS WITH TIME-DEPENDENT BOUNDARY CONDITIONS
Get PDFThis dissertation focuses on developing and analyzing numerical schemes for fractional partial differential equations (PDEs). The development is important because several models involving fractional derivatives exhibit non-locality and memory dependencies, making them difficult to solve. Moreover, many of such models do not have analytical solutions due to the non-linearity involved in their formulation.
In the first part of the study, we develop numerical schemes for space-fractional reaction-diffusion equations with time-dependent boundary conditions. The methods are based on using the matrix transfer technique (MTT) for spatial discretization, and rational approximations to the matrix exponential function are used in time. In particular, predictor-corrector schemes based on - and -Pad\'e, and a real distinct pole approximation to the exponential function are developed. We observe that the solutions produced by the -Pad\'e scheme incur oscillatory behavior for some time steps. These oscillations are due to high-frequency components present in the solution and diminish as the order of the space-fractional derivative decreases (slow diffusion). A priori reliability constraint is proposed to avoid these unwanted oscillations. Furthermore, the constraints are generalized for all -Pad\'e approximants, , to the matrix exponential functions.
In the second part of the study, a novel numerical scheme for time-space fractional PDEs is developed. The developed scheme is similar to the Crank-Nicholson scheme for integer-order PDEs and is shown to be of order in time, where is the order of the time derivative described in the Caputo sense. We implement the algorithms in parallel using the shared memory systems (OpenMP) and the distributed memory systems (MPI). We discuss the merits and demerits of each of the parallel versions of the algorithms. Error and stability analysis of the scheme is also discussed. Unlike the Crank-Nicholson scheme for integer-order PDEs, the derived scheme has a lower order (). This lower order is due to the singular kernel (as a result of the Caputo derivative) involved in the scheme's formulation. We used the time-graded mesh to improve the scheme's accuracy from to two.
The last part of the study focuses on applying fractional derivatives and, in particular, the derived schemes to a scientific domain. We propose a time-fractional compartmental model comprising the susceptible, exposed, infected, hospitalized, recovered, and dead population for the COVID-19 epidemic. The properties and dynamics of the proposed model are discussed. We run several model simulations and estimate parameters using the Center for Systems and Science Engineering data at John Hopkins University for some selected states in the US. Furthermore, the efficacy of contact tracing (CT) is investigated by linking the disease model dynamics with actions of contact tracers such as monitoring and tracking. CT's impact on the reproduction number of COVID-19 is described. In particular, the importance and relevance of the model parameters such as the number of reported cases, effectiveness of tracking and monitoring policy, and the transmission rates to CT are discussed.Ph.D
A Comparison of the Perceptions and Experiences of Undergraduate Students, Graduate Students, and Instructors in College and University Psychology Programs
Get PDFExtending the methods of previous research comparing the experiential perceptions of undergraduate and graduate psychology students by ethnic and gender identity, two survey instruments were developed for the purpose of comparing the experiential perceptions of psychology students with the experiential perceptions of psychology instructors by ethnic and gender identity. In contrast to earlier research, no significant differences were found in between undergraduate and graduate psychology student perceptions in relation to perceptions of ethnic diversity in academic environments. Additionally, no significant correlation was found between student satisfaction and reported student ethnic identity, student satisfaction and mentoring by instructors, encountered encouragement or barriers, perceived ethnic representation in psychology, and perceived ethnic and gender diversity in academic environments. Qualitatively, undergraduate and graduate students generally aligned in their experiential perceptions except with reported mentoring, with graduate students reporting having experienced greater degrees of mentoring. Additionally, graduate students reported lesser degrees of diversity in both psychology and their immediate academic environments. Instructor responses differed from undergraduate responses regarding mentoring, with undergraduates generally reporting having not been mentored by psychology instructors, and instructors reporting having mentored undergraduate and graduate students. Further refinement of the survey instruments used in the project is needed before the instruments can serve as effective tools to assist in gauging perceived representation and diversity in college and university psychology programs.M.A
AUTISM SPECTRUM DISORDER IN THE WORKPLACE: HOW DOES THE TIMING OF DISCLOSURE DECISIONS AFFECT INTERVIEW RATINGS?
Get PDFThis study investigated the effect that timing of a job candidates disclosure of their autism spectrum disorder (ASD) status during an interview effects their interview ratings. A mock interview of an actor portraying symptoms of ASD was provided to 87 participants (50 men, 34 women). Three conditions were randomly assigned to participants regarding disclosure: early disclosure, late disclosure, and no disclosure. Participants then provided an overall response rating for each interview question, as well as a rating regarding their likelihood to hire the candidate being interviewed. This study found that participants in the early disclosure condition gave higher ratings than those in the late disclosure condition regarding likelihood to hire. This study also found that participants gave higher ratings in the no disclosure condition than those in the late disclosure condition regarding likelihood to hire. This study did not find any statistically significant effects for disclosure differences on the interview question ratings.M.A
Building the Bridge: A Case Study for the Significance of Cross-Cultural Education in the 21st Century
Get PDFAs the world continues to advance, current events and international developments keep the citizens of the 21st Century involved in the Earth’s matters now more than ever. Everything from the fostering of the most interconnected and globalized time on Earth to international tensions with countries like China and the United States has brought about a need for individuals to understand the world for their personal growth and establish an informed worldview applicable to the 21st Century. This thesis delves into the Center for MTSU Chinese Music and Culture’s role in cross-cultural education through the lens of the experiences and perspectives of those involved with the Center, including MTSU faculty members, students of the Chinese Music Ensemble, and others. This thesis demonstrates cross-cultural education’s importance in building cultural bridges during these turbulent times
Engineering the TetO System to Test the Contribution of FKS1 to Yeast Cell Wall Strength
Get PDFSociety has a demand for manufactured proteins such as insulin, which can be
produced by the yeast Saccharomyces cerevisiae, but such proteins are not easily accessible due to this yeast’s rigid cell wall. I hypothesize that if S. cerevisiae cells were not able to make as much FKS1 protein (a protein involved in cell wall synthesis) they would exhibit reduced growth rates and weaker cell walls. The approach is to genetically reprogram the yeast to reduce production of FKS1 when exposed to doxycycline. To accomplish this, the native FKS1 and GSC2 genes were knocked out, leaving only the doxycycline regulated FKS1 gene. Compared to the wildtype yeast, the TetO regulated yeast exhibited a reduced growth rate when exposed to doxycycline. In pursuit of heterologous proteins, further experimentation of the TetO system may be considered. Different production platforms may prove more appropriate in future studies due to greater efficacy in reducing cell wall strength
Conversion of a Short Lipopeptoid into Longer Non-lipidated Repeat Peptoids with Improved Activity
Get PDFThe need for new antibiotics to treat antibiotic resistant bacteria has been a growing problem worldwide over the past several years. Bacteria are quickly developing modifications to render antibiotics useless due to overuse and misuse of medications. With the need for new classes of antibiotics, developing peptoids as potential antibiotics to treat nosocomial pathogens is the overarching goal of this research project. The ESKAPE bacteria are the focus of this research because of their well characterized global health risk. A series of monomer sequence repeat peptoids, termed the MNT series, were designed from a previously discovered lipopeptoid, termed ALA1. This was done in an effort to determine the peptoid length requirement when converting a short lipopeptoid into a longer non-lipidated peptoid. It was hypothesized that removing the lipid tail would reduce toxicity while lengthening the peptoid would allow for retention of antibacterial activity. A total of four MNT series peptoids (MNT1, MNT2, MNT3, and MNT4) ranging from 3 to 12 monomers in length without a lipid tail were synthesized and characterized for antibacterial efficacy and mammalian cytotoxicity. This research determined that MNT3, which is 9 monomers in length, was the most promising ALA1 derivative. This compound was more potent towards gram-positive pathogens, such as E. faecium, E. faecalis, and S. aureus than ALA1 or the longer MNT4 peptoid. In general, all non-lipidated MNT series peptoids were less effective against gram-negative bacteria than ALA1. Cytotoxicity testing of the MNT series peptoids and ALA1 against HepG2 liver cells and red blood cells indicated that MNT3 had lower cytotoxicity than ALA1 or MNT4. The shortest derivatives, MNT1 and MNT2 displayed no antibacterial activity or cytotoxicity, demonstrating the dependence of peptoid length or lipidation for both of these parameters.M.S
Training Idea Evaluation
Get PDFThe present study was one of the first to attempt training the idea evaluation phase of the creative process. Working memory, divergent thinking, and openness to experience were hypothesized to interact with the ability to train participants on idea evaluation. Participants were split into three groups (control, instructions, training). All three groups received three tasks and were asked to choose the most effective solution to the problem from a list. The control group was asked to only rate solutions to the tasks and were given no instructions or training. The instructions group was given limited instructions on the meaning of quality and originality in creativity after the first task. The training group was given the same instructions with examples and feedback on their responses after the first task. A repeated measures 3 x 3 ANOVA revealed no significant differences between groups. The only significant covariate was working memory. Divergent thinking and openness were nonsignificant.M.L.A