Statistics and Probability Commons^™

Effect Of Pre-Adsorbed Species On High-Pressure Adsorption Of Methane In Zeolite 5a Using Grand Canonical Monte Carlo (Gcmc) Simulations, Kanhamardi Lao, Brooks D. Rabideau

Shelby Hall Graduate Research Forum Posters

Natural gas upgrading, which removes impurities from methane (CH4), is essential for industrial applications, including liquefied natural gas (LNG) production and power generation, as well as for residential use. Removing non-hydrocarbon impurities such as carbon dioxide (CO2), nitrogen (N2), and water vapor (H2O), among others, along with separating heavier hydrocarbon gases from raw natural gas, is required to achieve high- purity methane and prevent pipeline corrosion. Zeolite 5A is a microporous aluminosilicate material with a pore size of approximately 5 Å, containing sodium and calcium cations that balance the framework’s negative charge. Its structure offers high thermal stability and a …

Analysis Of Nuclear Security And Safety Integration Using Survey Responses And Pairwise Comparison Methods, Sheila V. Gbormittah, Theodore A. Thomas, Jason Timothy Harris

International Journal of Nuclear Security

Integrating nuclear security and safety is important for implementing and sustaining nuclear technology because it promises improved and effective management. This integration is an ongoing effort to ensure that both work together with minimal conflicts. This research aimed to determine the preferred level at which nuclear security and nuclear safety integrate by using the pairwise comparison methods of decision-making. This methodology used survey responses from women nuclear professionals to identify the most-desired criteria at three levels: strategic, operational, and cultural. The strategic level includes actions that government officials and regulators can take. The operational level encompasses actions that deliver the …

A New Measure Of Non-Parametric Correlation For Variables In The Likert Scale, Shubhabrata Das

Working Papers

We propose a new measure of nonparametric correlation that is especially suited for measuring association between variables measured in the Likert scale where data is ordinal and tied observations are extremely common. The proposed general structure of the measure is based on graded level of concordance and discordance between the pairs of metrics. The general form of the measure has all the desirable properties except the measure is not necessarily zero for independent variables. This limitation is acceptable given only ordinal nature of the metrics. Three versions of the measure are studied. The first is based on simple equi-distant weights. …

Explainable Neural Networks With Guarantee: A Sparse Estimation Approach, Antoine Ledent, Peng Liu

Research Collection School Of Computing and Information Systems

Balancing predictive power and interpretability has long been a challenging research area, particularly in powerful yet complex models like neural networks, where nonlinearity obstructs direct interpretation. This paper introduces a novel approach to constructing an explainable neural network that harmonizes predictiveness and explainability. Our model is designed as a linear combination of a sparse set of jointly learned features, each derived from a different trainable function applied to a single 1-dimensional input feature. Leveraging the ability to learn arbitrarily complex relationships, our neural network architecture enables automatic selection of a sparse set of important features, with the final prediction being …

Generation Of Patient Specific Cardiac Chamber Models Using Generative Neural Networks Under A Bayesian Framework For Electroanatomical Mapping, Sunil Mathew, Jasbir Sra, Daniel B. Rowe

Mathematical and Statistical Science Faculty Research and Publications

Electroanatomical mapping is a technique used in cardiology to create a detailed 3D map of the electrical activity in the heart. It is useful for diagnosis, treatment planning and real time guidance in cardiac ablation procedures to treat arrhythmias like atrial fibrillation. A probabilistic machine learning model trained on a library of CT/MRI scans of the heart can be used during electroanatomical mapping to generate a patient-specific 3D model of the chamber being mapped. The use of probabilistic machine learning models under a Bayesian framework provides a way to quantify uncertainty in results and provide a natural framework of interpretability …

Modifiable And Non-Modifiable Risk Factors For Dementia Among Non-Hispanic White And Black Populations Aged 50-64 In The United States, 2006-2016, Jingkai Wei, Matthew C. Lohman Ph.D., Monique J. Brown, James W. Hardin, Chih-Hsiang Yang, Anwar T. Nerchant, Daniela B. Friedman

Faculty Publications

Background and Objectives

Research Design and Methods

Adverse Childhood Experiences, Resilience, And Syringe Services Program Attendance Among Persons Who Inject Drugs In Northeast Georgia, Usa: A Mediation Analysis, Mohammad Rifat Haider, Samantha Clinton, Monique J. Brown, Nathan B. Hansen

Faculty Publications

Background: Syringe services programs (SSP) are evidence-based venues offering harm reduction services to persons who inject drugs (PWID), such as sterile syringes, STI/HIV testing, and linkage to care to decrease drug use-related morbidities and mortalities. Adverse childhood experiences (ACEs) have been linked with reduced resilience, while increased resilience can help PWID attend SSPs. This study examined the potential mediating role of resilience between ACEs and SSP attendance among PWID.

Methods: Data were collected from adult HIV-negative PWID in northeast Georgia, between February-December 2023 (N = 173). Data were collected on SSP attendance (Yes vs. No), resilience, and ACEs. Covariates included …

Geographic Disparities In Unpaid Caregiving, Emma Kathryn Boswell, Monique J. Brown Ph.D., Mph, Lorie Donelle Phd, Rn, Fcan, Nicholas Yell, Taryn Farrell, Peiyin Hung Ph.D., Elizabeth Crouch Ph.D.

Faculty Publications

Purpose: An updated, nationally representative examination of rural–urban differences in the experiences, health, and well-being of caregivers is needed; previous research on this topic uses older data or has limited generalizability. This study examines rural–urban differences in the characteristics, experiences, and health of caregivers. Methods: The 2021–2022 Behavioral Risk Factor Surveillance System (n = 44,274 unpaid caregivers) was used, with rurality defined according to the 2013 National Center for Health Statistics (NCHS) Urban-Rural Classification Scheme. Chi-square tests compared rural–urban differences in these caregivers’ characteristics, including demographic factors, caregiving intensity (e.g., weekly hours spent caregiving, reason for caregiving, past-month ADL/IADL assistance), …

Optimal Time Series Forecasting Through The Garma Model, Adel Hassan A. Gadhi, Shelton Peiris, David E. Allen, Richard Hunt

Research outputs 2022 to 2026

This paper examines the use of machine learning methods in modeling and forecasting time series with long memory through GARMA. By employing rigorous model selection criteria through simulation study, we find that the hybrid GARMA-LSTM model outperforms traditional approaches in forecasting long-memory time series. This characteristic is confirmed using popular datasets such as sunspot data and Australian beer production data. This approach provides a robust framework for accurate and reliable forecasting in long-memory time series. Additionally, we compare the GARMA-LSTM model with other implemented models, such as GARMA, TBATS, ARIMA, and ANN, highlighting its ability to address both long-memory and …

Exploring The Potential Of Strongly Coupled Lagrangian Data Assimilation In An Ocean–Atmosphere System, Luyu Sun, Amit Apte, Laura Slivinski, Elaine T. Spiller

Mathematical and Statistical Science Faculty Research and Publications

Precise measurements of ocean surface flow velocities are essential for refining forecasts in a coupled ocean–atmosphere system. While oceanic data are generally sparse, surface drifters present an opportunity by providing detailed and frequently observed sea surface currents, which are a critical component in the dynamics at air–sea interface. Such observations could potentially address the usual data gaps in a coupled ocean–atmosphere assimilation system. In this study, we investigate the implications of assimilating drifter data within a coupled system with intermediate complexity based on a quasigeostrophic model—Modular Arbitrary-Order Ocean–Atmosphere Model (MAOOAM)—using observing system simulation experiments (OSSEs). Two main strategies for assimilating …

Prevalence Of Low Back Pain Among Office Workers During The Covid-19 Pandemic In Various Countries: A Systematic Review, Yosephine Roma Intan, Ririn Arminsih Wulandari, Popy Yuniar

Kesmas

The COVID-19 pandemic has led to the implementation of work from home policies in almost all parts of the world. This policy has increased the onset of musculoskeletal disorders in workers, such as low back pain (LBP). This study aimed to examine the prevalence of LBP among office workers during the COVID-19 pandemic after implementing WFH policies. This study was performed using data from various countries to determine the relationship between LBP and several risk factors, specifically age, sex, physical activity, ergonomic factors, as well as work environment factors such as temperature, humidity, lighting, noise, and work duration. A systematic …

Poisson Lindley-Quasi Xgamma Distribution For Count Data: Properties And Applications, Seth Borbye, Suleman Nasiru, Kingsley Kuwubasamni Ajongba, Sampson Wiredu

Al-Bahir

The literature contains innumerable probability distributions for modeling over-dispersion and under-dispersion count datasets from various fields of study. However, some of these proposed distributions are inadequate due to empirical or theoretical characteristics. Therefore, minimizing information loss during modeling has prompted the demand to modify the classical discrete distributions. A new two-parameter count distribution is proposed by combining Poisson and Lindley-quasi XGamma distributions via a continuous mixture technique. Some statistical properties have been derived and studied, including factorial moments, raw moments, probability generating function, moment generating function, characteristic function, mean, variance, dispersion index, skewness, and kurtosis. The shape of the PMF …

Leveraging Bayesian And Classical Techniques For Survival Analysis Using The Weibull-Rayleigh Distribution, Mahmoud Mansour, Rashad El-Sagheer, Nagwa Mohamed

Basic Science Engineering

This paper contributes to an extensive analysis of the Weibull-Rayleigh distribution (WRD), including Bayesian inference for randomly censored data. The WRD is a versatile model that fits various types of survival data, especially in situations including censoring, commonly found in biostatistics and engineering reliability research. The research investigates the derivation of the WRD’s probability density and cumulative distribution functions, employing maximum likelihood estimation (MLE) and Bayesian estimating techniques to accurately infer parameters. Gamma priors are utilized in Bayesian analysis, and approximate Bayesian estimates are derived by Gibbs sampling and Lindley’s approximation methods. An actual dataset that represents leukemia-free survival times …

Mechanism Of Mud Pumping On Plateau Highway Under Traffic Loads And Its Treatment Strategy, Zhang Junhui, Chen Zhide, Gao Feng, Na Qicai, Ma Pengfei, Xiao Lin

Journal of China & Foreign Highway

The dynamic hydraulic response and particle migration of subgrade structures under traffic loads are fundamental to reveal the formation and development mechanisms of mud pumping.The driving mechanism of fine particle migration in the mud pumping state was explored by conducting laboratory tests on layered gravel-sandy silt columns under dynamic loads.The results show that the slurry sloshing causes alternating positive and negative pressure gradients within the gravel layer.This oscillating pressure gradient enhances the pore permeability in the underlying sandy silt layer,providing the necessary hydrodynamic conditions for fine particle migration.Fine particle migration increases the slurry turbidity to a stable value.Upon the removal …

Risk Zoning Of Hazards Along Highways To Xizang Based On Information Model, Liu Weimin, Guo Guanmiao, Cai Qing ’E, Yu Xueyong, Dong Xiaobo, Chen Peicong

Journal of China & Foreign Highway

The frequent occurrence of hazards along the highways in the Qinghai ‒ Xizang Plateau seriously affects road traffic and threatens the security of lives and property of the people.Conducting a risk zoning assessment of hazards along the highways to Xizang is crucial to enhancing hazard prevention and mitigation.This paper summarized the regional geological environment and development patterns of hazards along the highways to Xizang and analyzed the overall performance of highway traffic operations.On this basis,the Xinjiang‒Xizang Highway was taken as the research object,and the evaluation factors were selected based on the regional geological environment and the main controlling factors of …

Seismic Performance Of Bridge Pile Foundation Considering Effects Of Material Freeze-Thaw Deterioration And Permafrost Degradation, Zhang Xiyin, Yu Shengsheng, Wang Wanping, Wen Hairong

Journal of China & Foreign Highway

In cold and high-seismic regions,such as the Qinghai‒Xizang Plateau in China,the deterioration of material properties caused by freeze-thaw cycles and permafrost degradation due to climate change have become increasingly severe,posing significant challenges for the seismic performance assessment of bridge pile foundations.To systematically investigate the impact of permafrost degradation and material freeze-thaw deterioration on the seismic performance of bridge pile foundations and ensure proper seismic design,a finite element model was established,considering the dual effects of permafrost degradation and material freeze-thaw deterioration.A comparative analysis was conducted to evaluate the influence mechanisms of various factors on the seismic performance of bridge pile foundations …

Cracking Characteristics Of Cement-Stabilized Macadam With Early Strength Agent Under Variable Temperature And Humidity Curing Conditions, Ge Dongdong, Liu Dingyuan, Lyu Songtao, Jiang Xiangyang, Xue Yanhua, Yu Yang

Journal of China & Foreign Highway

In environments with large temperature variations and low humidity,the curing conditions of cement-stabilized macadam fail to meet the specifications,leading to slow early strength development and increased susceptibility to cracking.This study aimed to investigate the effects of actual environmental temperature,humidity,curing age,and addition of early strength agents on the cracking characteristics of cement-stabilized macadam.Variable temperature conditions were determined based on actual environmental temperature data.Four curing conditions were set by combining temperatures (variable temperature and standard temperature ) with relative humidity of 95%,80%,and 65%,respectively.Three types of specimens were prepared with 0%,10%,and 15% early strength agent contents and cured for 14 and 28 days,respectively.The …

Identification And Prediction Model For Traffic Blockage State Of Highways To Xizang, Wu Ling, Liu Jianbei, Zhang Zhiwei, Shan Donghui, Chi Gandu

Journal of China & Foreign Highway

To identify the traffic blockage state on highways to Xizang in extreme environments,comprehensive evaluation indicators for traffic blockage state based on the entropy-weighted TOPSIS method were proposed by using the traffic blockage event parameters observed on four major highways to Xizang:Sichuan ‒ Xizang Highway,Yunnan ‒ Xizang Highway,Qinghai ‒ Xizang Highway,and Xinjiang ‒ Xizang Highway.The K-Medoids clustering algorithm was used to categorize the traffic blockage state into different levels.By considering factors such as hazard types,road types,traffic volume,and vehicle type ratios,a classification model for the traffic blockage state on highways to Xizang was constructed based on machine learning algorithms.The results show that …

Influence Of Urease-Induced Calcium Carbonate Precipitation On Frost Heave Characteristics Of Saline Soil, Li Jue, Wen Zili, Liu Zhengnan

Journal of China & Foreign Highway

This study investigated the impact of the soybean urease-induced calcium carbonate precipitation (SICP ) technique on frost heave characteristics of saline soil,specifically addressing the frost heave in saline soil used as a subgrade.The relationships between compaction degree,moisture content,volume ratio of the reaction liquid,and curing temperature with the frost heave rate of treated soil were explored.The results show that SICP significantly reduces the frost heave rate of soil samples by over 28%,with the most noticeable improvement occurring under conditions of higher compaction degree and lower moisture content.Additionally,the increased volume ratio of reaction liquid enhances reaction efficiency,while lower curing temperatures are crucial …

Prediction And Evaluation Of Road Service Performance In Cold Regions Based On Uncertainty Quantification Theory, Liu Yuanyuan, Si Junling, Zheng Hao, Ren Daoju, Fan Shaobing, Quan Lei

Journal of China & Foreign Highway

In cold regions,road service performance is influenced by various nonlinear dynamic factors under complex hydrothermal environments and freeze-thaw cycles.Traditional empirical and mechanical models exhibit significant limitations in comprehensively considering the impacts of complex environments and conducting quantitative analyses.This study proposed a method to predict and assess the service performance of constructed roads in cold regions.The method integrated deep neural networks with uncertainty quantification theory,addressing the inadequacies of existing models in adapting to complex environments and analyzing multiple influencing factors.By utilizing data from Montana road sections in the LTPP database,the study employed deep neural networks to predict the international roughness index …