Statistics and Probability Commons^™

Posterior Predictive Critique Of A Psychometric Bayesian Model For Assessing Aphasia, Ashlynn Crisp

Mathematics and Statistics Dissertations, Theses, and Final Project Papers

For persons with aphasia, naming tests are useful for assessing the severity of the disease and observing progress toward recovery. The Philadelphia Naming Test (PNT) is a leading naming test composed of 175 items. The items are common nouns which are one to four syllables in length and with low, medium, and high frequency. Since the target word is known to the administrator, the response from the patient can be classified as correct or an error. If the patient commits an error, the PNT provides procedures for classifying the type of error in the response. Item response theory can be …

The Fundamental Limit Theorem Of Countable Markov Chains, Nathanael Gentry

Senior Honors Theses

In 1906, the Russian probabilist A.A. Markov proved that the independence of a sequence of random variables is not a necessary condition for a law of large numbers to exist on that sequence. Markov's sequences -- today known as Markov chains -- touch several deep results in dynamical systems theory and have found wide application in bibliometrics, linguistics, artificial intelligence, and statistical mechanics. After developing the appropriate background, we prove a modern formulation of the law of large numbers (fundamental theorem) for simple countable Markov chains and develop an elementary notion of ergodicity. Then, we apply these chain convergence results …

Quan 201: Quantitative Reasoning And Society, Cuny School Of Professional Studies

Open Educational Resources

An interdisciplinary introduction to the ways in which data can be used to enhance thinking and decision-making capacities, including using simple statistical techniques, creating visual representations of quantitative data, deriving accurate conclusions from quantitative data, and using data effectively in analyses and arguments. Assignments build capacity to evaluate and write clearly about quantitative evidence using methods for analyzing and communicating about data that do not require complex mathematics.

Bayesian Methods In Analyzing The Association Of Random Variables, Zichen Ma

Theses and Dissertations

This dissertation focuses on studying the association between random variables or random vectors from the Bayesian perspective. In particular, it consists of two topics: (1) hypothesis testing for the independence among groups of random variables; and (2) modeling the dynamic association between two random variables given covariates.

In Chapter 2, a nonparametric approach for testing independence among groups of continuous random variables is proposed. Gaussian-centered multivariate finite Polya tree priors are used to model the underlying probability distributions. Integrating out the random probability measure, a tractable empirical Bayes factor is derived and used as the test statistic. The Bayes factor …

Statistical Analysis Of A Joint Stochastic Model For Recurrent Competing Risks, Longitudinal Marker, And Health Status, Lili Tong

Theses and Dissertations

Joint modeling approach has been applied in many applications in biomedical, reliability, and social-economic research. For example, in clinical trials and medical research, different kinds of patient information are gathered over time, such as recurrent competing risk events (e.g., relapses of different types of tumor), longitudinal marker (e.g., tumor size), and health status (e.g., if a patient is dead or not). These data are usually correlated, joint models enable the analysis of these correlated data. This dissertation proposes a class of joint dynamic models for simultaneously modeling the three types of processes: a recurrent competing risk (RCR) process, a health …

Bayesian Nonparametric Model For Functional Data Analysis, Tahmidul Islam

Theses and Dissertations

Functional data analysis (FDA) experienced a burst of growth after Ramsay and Silverman published their textbook in 1997. Functional data analysis interests researchers because of the challenges it adds to well-established multivariate analysis. Unlike finite dimensional random vectors, we visualize infinite dimensional random functions; for example, curves, images, brain scans, etc. A vast amount of literature have been dedicated to developing models for functional data. The ideas are mostly based on basis function representations and kernel-based nonparametric methods. In this dissertation, we propose a Bayesian treatment of nonparametric functional data analysis by introducing a Gaussian process (GP) over the space …

The Pharmaceutical Industry Contributes To Public Health, Karl E. Peace, Mario Keko

Biostatistics, Epidemiology & Environmental Health Sciences: Faculty Publications

No abstract provided.

The Absence Or Misuse Of Statistics In Forensic Science As A Contributor To Wrongful Convictions: From Pattern Matching To Medical Opinions About Child Abuse, Keith A. Findley

Dickinson Law Review (2017-Present)

The new scrutiny that has been applied to the forensic sciences since the emergence of DNA profiling as the gold standard three decades ago has identified numerous concerns about the absence of a solid scientific footing for most disciplines. This article examines one of the lesser-considered problems that afflicts virtually all of the pattern-matching (or “individualization”) disciplines (largely apart from DNA), and even undermines the validity of other forensic disciplines like forensic pathology and medical determinations about child abuse, particularly Shaken Baby Syndrome/Abusive Head Trauma (SBS/AHT). That problem is the absence or misuse of statistics. This article begins by applying …

An Assessment Of Terrestrial Decapoda Diversity Across Three Ecological Zones In Mida Creek, Kenya, Reese Yount

Independent Study Project (ISP) Collection

Mangroves make up one of the most effective natural remedies at combating climate change today. They represent great commercial interest worldwide and yet, are being degraded at an unsustainable rate. If successful mangrove conservation plans are to be implemented for our posterity, mangrove ecosystems need to be better understood at the community level. Mangrove crabs make up the most diverse and populace mangrove inhabitants. They are classified as ecosystem engineers and their potential for being used as bioindicators makes them integral to assessing mangrove health. Yet, their diversity and distribution patterns are not well understood. The aim of this study …

Taxonomic Annotation Of Near-Coral Seawater Microbiota In Kilifi, Kenya, Megan Ruoff

Independent Study Project (ISP) Collection

The general objective of this study was to analyze the microbiome of seawater above a coral reef in Kilifi, Kenya. Specific objectives included establishing a baseline microbiota profile, classifying the identified organisms at various taxonomic levels, and conjecturing about reef health from the presence or absence of bioindicator species including Vibrio bacteria. Sequenced 16S rRNA gene sequences from seawater samples at Kuruwitu Conservancy in Kilifi, Kenya were taxonomically classified by exact matching employing the Dada2 software package and the naïve Bayesian classifier method with 97% similarity cut off. The seawater microbiota contained mostly Proteobacteria (73.28%), followed by Bacteroidetes (14.08%) and …

On The Burr Xii-Power Cauchy Distribution: Properties And Applications, Fiaz Ahmad Bhatti, Gholamhossein Hamedani, Mashail M. Al Sobhi, Mustafa Ç. Korkmaz

Mathematical and Statistical Science Faculty Research and Publications

We propose a new four-parameter lifetime model with flexible hazard rate called the Burr XII Power Cauchy (BXII-PC) distribution. We derive the BXII-PC distribution via (i) the T-X family technique and (ii) nexus between the exponential and gamma variables. The new proposed distribution is flexible as it has famous sub-models such as Burr XII-half Cauchy, Lomax-power Cauchy, Lomax-half Cauchy, Log-logistic-power Cauchy, log-logistic-half Cauchy. The failure rate function for the BXII-PC distribution is flexible as it can accommodate various shapes such as the modified bathtub, inverted bathtub, increasing, decreasing; increasing-decreasing and decreasing-increasing-decreasing. Its density function can take shapes such as exponential, …

Neurodevelopment Correlates With Gut Microbiota In A Cross-Sectional Analysis Of Children At 3 Years Of Age In Rural China, Sarah E. Rothenberg, Qiurong Chen, Yanfen Nong, Hua Nong, Eva P. Trinh, Fred J. Biasini, Jihong Liu, Xiaoyun Zeng, Yunfeng Zou, Fengxiu Ouyang, Susan A. Korrick

Faculty Publications

We investigated cross-sectional associations between children’s neurodevelopment and their gut microbiota composition. Study children (36 months of age) lived in rural China (n = 46). Neurodevelopment was assessed using the Bayley Scales of Infant Development, 2nd Edition, yielding the Mental Developmental Index (MDI) and Psychomotor Developmental Index (PDI). Children's gut microbiota was assessed using 16S rRNA gene profiling. Microbial diversity was characterized using alpha diversity patterns. Additionally, 3 coabundance factors were determined for the 25 most abundant taxa. Multivariable linear regression models were constructed to examine the relationships between Bayley scores (MDI and PDI) and children's gut microbiota. In adjusted …

The Dietary Inflammatory Index Is Associated With Low Muscle Mass And Low Muscle Function In Older Australians, Marlene Gojanovic, Kara L. Holloway-Kew, Natalie K. Hyde, Mohammadreza Mohebbi, Nitin Shivappa Mbbs, Mph, Ph.D., James R. Hébert Scd., Adrienne O'Neil, Julie A. Pasco

Faculty Publications

Age-associated chronic, low grade systemic inflammation has been recognised as an important contributing factor in the development of sarcopenia; importantly, diet may regulate this process. This cross-sectional study examined the association of diet-related inflammation with components of sarcopenia. Participants (n = 809) aged 60–95 years from the Geelong Osteoporosis Study were studied. Body composition was measured by dual energy X-ray absorptiometry. In this study, low appendicular lean mass (ALM/height2, kg/m2) was defined as T-score < −1 and low muscle function as Timed-Up-and-Go >10 s over 3 m (TUG > 10). Dietary inflammatory index (DII®) scores, based on specific foods and nutrients, were computed using dietary data collected from a …

Does Defense Actually Win Championships? Using Statistics To Examine One Of The Greatest Stereotypes In Sports, Thomas Burkett

Senior Theses

A common saying in sports is that “defense wins championships.” However, the past decade of play in the modern NBA has seen a rise and focus in offensive efficiency and 3-pointers. This thesis tests whether defense can truly predict a championship winning team in today’s NBA through two-sample hypothesis testing and multiple logistic regression models. The results found that both defensive and offensive statistics were significant predictors of championship teams, meaning that a balanced team, rather than one specialized in defense alone, is a more accurate predictor of championship success.

Perceived Discrimination And Racism On The Treatment And Medication Adherence Of Hypertension In African Americans, Ifeoluwa Kayode, Daisy Tovar, Logan Cowan

Biostatistics, Epidemiology & Environmental Health Sciences: Faculty Publications

No abstract provided.

A Simulation-Based Study Of Location-Shift Models Under Non-Normal Conditions, Ummay Khayrunnesa Anika

Theses and Dissertations

In this study, we compare ordinary least squares (OLS), generalized least squares (GLS), M- and quantile regression (QR) estimators for a continuous response variable under different scenarios by conducting a simulation study. We assess the performance of the estimators in terms of bias, average distance, mean squared error, coverage probability, and ratio of estimated standard error and empirical standard deviation. OLS estimator performs the best when the errors are homoscedastic normal or homoscedastic but skewed (exponential) having no outliers. GLS estimator shows good comparative results to QR when the errors are heteroscedastic normal or heteroscedastic heavy-tailed (t-distributed). The most satisfactory …

Improving Failure Mode & Effect Analysis ( Fmea ) Method Using Discrete Event Simulation, Adil Abdukeyum

Theses and Dissertations

To improve system performances and process dependability, analyzing the system accurately is an essential step but difficult to achieve and it is even more challenging if the system is complex and dynamic. A popular tool called FMEA has been widely used to analyze and improve systems. However, both academia and industry acknowledge its subjectivity and lack of cause-effect analysis capability. Therefore, in this research, the author presents a more objective and data-driven method called Discrete Event Simulation to improve FMEA’s analysis capability. Also, how the Discrete Event Simulation may enhance the FMEA by a step-by-step analysis approach is presented by …

Commodity Futures Returns And Policy Uncertainty, Deepa Bannigidadmath, Paresh Kumar Narayan

Research outputs 2014 to 2021

This paper investigates whether economic policy uncertainty is predictable using three sets of commodity futures market variables, namely the equal-weighted average of futures excess returns, the excess returns on a portfolio of going long in backwardated commodities, and the excess returns on a portfolio of going short in contango commodities as predictors. We find significant evidence of both in-sample and out-of-sample predictability. Combination forecasts also reveal strong evidence of predictability. Our findings remain unchanged following several robustness tests.

Financial News And Cds Spreads, Paresh Kumar Narayan, Deepa Bannigidadmath

Research outputs 2014 to 2021

This paper examines whether financial news moves CDS spreads for a large number of U.S. stocks sorted into 19 panels consisting of sectors, sizes and credit quality. Using a unique financial news data set, we discover that while both positive and negative news predicts CDS spread changes in most of the panels, annualised mean–variance profits and utility gains are dominated by forecasting models that use positive news as a predictor. At best, risk factors only account for around 31% of observed profits.

Adventuring Into Complexity By Exploring Data: From Complicity To Sustainability, Tim Lutz

Northeast Journal of Complex Systems (NEJCS)

Problems of sustainability are typically represented by major present-day challenges such as climate change, biodiversity loss, and environmental and social injustice. Framed this way, sustainable lives and societies depend on finding solutions to each problem. From another perspective, there is only one problem behind them all, stated by Gregory Bateson as: “…the difference between how nature works and the way people think,” and complexity provides a way to define and approach this problem. I extend Edgar Morin’s conceptions of restricted and general complexity into pedagogy to address problems of simplicity and reductionist teaching. The proposed pedagogy is based on long …