Statistics and Probability Commons^™

Quasi – Monte Carlo Estimation For Functional Generalized Linear Mixed Models, Ruvini Jayamaha

Waldo Library Student Exhibits

Functional Data Analysis (FDA) is a topic of growing interest in the Statistics community. The data in FDA are smooth curves or surfaces in time or space which can be conceptualized as functions.

We propose a Functional Generalized Linear Mixed Model (FGLMM) to fit EEG data and estimate the parameters using Quasi-Monte Carlo Method.

This proposed model deals with non-Gaussian scalar response, functional predictor, and random effects. We relax the assumption of link and variance functions.

Gauss Newton Method For Solving Variational Problems Of Pdes With Neural Network Discretizaitons, Wenrui Hao, Qingguo Hong, Xianlin Jin

Mathematics and Statistics Faculty Research & Creative Works

The numerical solution of differential equations using machine learning-based approaches has gained significant popularity. Neural network-based discretization has emerged as a powerful tool for solving differential equations by parameterizing a set of functions. Various approaches, such as the deep Ritz method and physics-informed neural networks, have been developed for numerical solutions. Training algorithms, including gradient descent and greedy algorithms, have been proposed to solve the resulting optimization problems. In this paper, we focus on the variational formulation of the problem and propose a Gauss–Newton method for computing the numerical solution. We provide a comprehensive analysis of the superlinear convergence properties …

Ocular Gene Transfer In The Spotlight: Implications Of Newspaper Content For Clinical Communications, Shelly Benjaminy, Tania M. Bubela

Office of the Provost

Background: Ocular gene transfer clinical trials are raising hopes for blindness treatments and attracting media attention. News media provide an accessible health information source for patients and the public, but are often criticized for overemphasizing benefits and underplaying risks of novel biomedical interventions. Overly optimistic portrayals of unproven interventions may influence public and patient expectations; the latter may cause patients to downplay risks and over-emphasize benefits, with implications for informed consent for clinical trials. We analyze the news media communications landscape about ocular gene transfer and make recommendations for improving communications between clinicians and potential trial participants in light of …

Enacting Data Context: Fixing Meaning In Transparency Data Initiatives, Lindsay Poirier

Statistical and Data Sciences: Faculty Publications

This article documents the “context cultures” underpinning efforts to develop regulations for collecting and reporting data in a United States public database known as Open Payments. Open Payments is a dataset published annually by the US Center for Medicare and Medicaid Services that documents the transfers of value from pharmaceutical and medical device manufacturers to physicians, prescribing non-physicians, and teaching hospitals. In the article, I show context became a manifold concern as differentially-situated actors engaged in modes of public advocacy and social action around not only what data meant, but also what it meant to make data meaningful. I show …

Multi-Case Study Of Left-Flank Boundaries Within Supercells, Peyton B. Stevenson

Department of Earth and Atmospheric Sciences: Dissertations, Theses, and Student Research

This study investigates the prevalence and significance of forward-flank convergence boundaries (FFCBs) and left-flank convergence boundaries (LFCBs) in shaping the structure and intensity of supercells, using observational data from various field projects. Unlike previous research focusing on individual cases, this study examines a diverse range of cases to provide comprehensive insights into the relationship between these boundaries and supercell characteristics such as intensity, longevity, and tornadogenesis. By analyzing high-resolution surface data, the research addresses the frequency, location, and intensity of these boundaries, and their impact on pseudo vertical vorticity, pseudo convergence, and density gradients. A total of 228 boundary identifications …

Design And Evaluation Of An Esa-Based Method Of Ensemble Subsetting For A Wofs (Warn On Forecast-Like System), Daniel J. Butler

Department of Earth and Atmospheric Sciences: Dissertations, Theses, and Student Research

Forecasting severe thunderstorm environments in the southeastern United States can be challenging due to mesoscale heterogeneities such as shortwave troughs, pre-existing airmass boundaries, cold fronts aloft, low-level jets, dry air intrusions, and mesoscale lows. To combat these challenges, ensemble sensitivity analysis (ESA) may be applied to a Warn-on-Forecast (WOF)-like ensemble to improve forecasts of severe convection through ensemble weighting and subsetting. Ensemble-based weighting and subsetting uses ensemble members that most accurately represent the thunderstorm environment in areas of mesoscale heterogeneity. This study creates and evaluates the ensemble-based weighting and subsetting in four cases of severe thunderstorm occurrence. The open parameter …

Phylogeny And Disparity Of Ammonoid Family Acanthoceratidae Over Ocean Anoxic Event 2, Lindsey Howard

Department of Earth and Atmospheric Sciences: Dissertations, Theses, and Student Research

The widespread use of genera as proxies for species in paleobiological studies might affect the results of these studies. Although most attention has been given to taxonomic diversity studies, this could also be true of disparity and phylogenetic studies. In particular, the assumption that particular character states truly diagnose all members of a genus might distort results. This study examines the disparity of Acanthoceratid ammonoids at both the generic and species level. 149 species from 42 genera were examined with 52 characters measured. Following the measurements, an inverse modeling simulation was run 100 times to generate a simulated phylogeny with …

A Probabilistic Approach To Estimate The Temporal Order Of Pathway Mutations Accounting For Intra-Tumor Heterogeneity, Menghan Wang, Yanqi Xie, Jinpeng Liu, Austin Li, Li Chen, Arnold Stromberg, Susanne Arnold, Chunming Liu, Chi Wang

Markey Cancer Center Faculty Publications

The development of cancer involves the accumulation of somatic mutations in several essential biological pathways. Delineating the temporal order of pathway mutations during tumori- genesis is crucial for comprehending the biological mechanisms underlying cancer development and identifying potential targets for therapeutic intervention. Several computational and statistical methods have been introduced for estimating the order of somatic mutations based on mutation profile data from a cohort of patients. However, one major issue of current methods is that they do not take into account intra-tumor heterogeneity (ITH), which limits their ability to accurately discern the order of pathway mutations. To address this …

Contributions To Nonparametric Testing In Clustered Data, Hasika Kalani Wickrama Senevirathne

Mathematics & Statistics Theses & Dissertations

Clustered data refers to a specific kind of correlated data where units within the same cluster are correlated while units from different clusters are independent. The number of units in each cluster, known as the cluster size, can be associated with the cluster’s outcome. This is known as the informative cluster size (ICS) and affects the inference drawn from clustered data. Recently, a hypothesis testing method has been developed to detect the presence of ICS. However, considering ICS alone may not be sufficient when comparing outcomes across multiple groups of units within clustered data. The size of a group within …

Comparison Of Value At Risk Using Historical And Monte Carlo Methods On Pt Xyz Stock Portofolio, Eka Fitriani, Yulial Hikmah, Ira Rosianal Hikmah

Jurnal Administrasi Bisnis Terapan

One way to achieve profits in a company is through investment activities. However, everything has risks. Investing can also be risky. Therefore, the relationship between risk and investment is important because it will influence the determination of investment selection. The problem faced by investors is choosing an efficient portfolio, or a portfolio that provides the smallest risk. This risk can be done by measuring risk, one of which is using the Value at Risk (VaR) measure. Measurement using Value at Risk has several methods that are quite popular, namely the Historical Method, Variance-Covariance, and Monte Carlo. In this research, the …

Evaluating Past Progress And Assessing Prediction Breeding Strategies For Sustained Genetic Gains In The Louisiana Sugarcane Variety Development Program, Brayden A. Blanchard

LSU Doctoral Dissertations

The aim of this dissertation is to outline important considerations for the Louisiana Sugarcane Variety Development Program (LSVDP) as it pertains to historical progress, impact, goal setting, and new strategies for continued genetic gains. Industry progress was evaluated with robust regression models to quantify rates of productivity gains. Over the last 50 years, statistically significant productivity gains were identified in sucrose content (45%), cane yield (32.2%), and sugar yield (93%) while pairwise comparisons of decades showed that progress was incremental rather than rapid and sustained once achieved. The decade from 1990-1999 was identified as the only decade with a significant …

Pollution Characteristics Of Heavy Metals In Solid Waste Subgrade Filling Materials, Du Qianhui, Fu Wei, Zhang Junhui, Tang Qiang, Gu Fan

Journal of China & Foreign Highway

Using solid waste in the road engineering field for subgrade filling is an important approach for building green and low-carbon emission roads.However,most solid waste contains heavy metal pollutants to varying degrees,and heavy metals will be released under complex environments including rainfall infiltration and groundwater immersion,thereby causing pollution to the surrounding soil and groundwater if not handled properly.This paper reviewed the current status of research on four aspects,including the comprehensive use of solid waste materials in subgrade engineering,the leaching and migration behaviors of heavy metals in solid waste,and the prevention and control treatment of heavy metals in solid waste.It is found …

Experimental Study On Influence Of Adsorbed Bound Water On Strength And Permeability Characteristics Of High Liquid Limit Soil, Fu Ceyuan, Zhou Shijie

Journal of China & Foreign Highway

In order to reveal the influence of adsorbed bound water on the strength and permeability characteristics of high liquid limit soil,the initial adsorbed bound water content of the high liquid limit soil specimens from Hunan and Hainan was controlled by different concentrations of sodium chloride solution,and thermogravimetric analysis method was used to determine the content.The direct shear test,unconfined compressive strength test,and permeability test were carried out.The results show that the adsorbed bound water content decreases with the increase in salt solution concentration,while the strong bound water content is basically unchanged.The adsorbed bound water has a high viscosity,low activity,and certain solid-like …

Analysis Of Asphalt Pavement Structure Based On Master Curve Parameters Of Dynamic Modulus Of Asphalt Mixture, Liu Zhaohui, Yang Xin, Huang You, Liu Li

Journal of China & Foreign Highway

In order to study the effect of the change in the master curve parameters of the dynamic modulus of asphalt mixture and the interaction on the structural response of asphalt pavement,a three-dimensional model of the asphalt pavement structure was established using the finite element method,and the structural calculations of asphalt pavement with semi-rigid base and flexible base were carried out.The master curve parameters of the dynamic modulus δ,α,β,and γ were taken as the influencing factors,and the maximum tensile strain at the bottom of the asphalt layer and the vertical compressive strain at the top of the subgrade were set as …

Mechanism Of Water‑Damaged Landslides Of Embankments And Comparison Of Reinforcement Measures, Hu Minghua, Zhang Baiyong, Xu Kui

Journal of China & Foreign Highway

Water damage to embankments serious ly affects the normal operation of highways,so it is extremely important to ensure the stability of the embankment.In addition,it is necessary to analyze the mechanism and study the safety control measures for water-damaged landslides of the embankment.A highway subgrade embankment was studied,and the causes and formation mechanism of the landslide were qualitatively analyzed based on the on-site deformation monitoring and stability calculation.Then,the stability coefficients of different reinforcement schemes were calculated.An appropriate reinforcement scheme was recommended by considering the project cost,construction technology,and construction period.The results indicate that uneven settlement of the embankment stratum is the fundamental …

Effect Of Cellulose Fiber On Humidity Control And Properties Of Cement Mortar, Liang Jinguo, Ma Baofu

Journal of China & Foreign Highway

To explore the effect of flax cell ulose fiber on the humidity and basic properties of cement mortar,this paper adopted flax cellulose fibers with different lengths (0.5 and 5 mm ) and mixing amounts (mass fraction of 0.5%,1%,1.5%,and 2% of cement ).Tests were conducted on rheological properties,mechanical properties,autogenous shrinkage properties,and internal relative humidity development of cement mortar.Setting time,compressive strength,shrinkage rate,and relative humidity were used to evaluate the performance improvement effect of cellulose fiber on cement mortar.The results show that the absorbance rate of flax fiber per unit mass of 0.5 mm is 3.45 times its weight,while the absorbance rate of …

Micro Mechanical Analysis And Experiment On Fatigue Damage Of Rubber Powder Asphalt Mixture Of Expressway, Li Nanpeng, Wang Guoqing, Wang Zhibin, Zhang Xia3, Si Chundi

Journal of China & Foreign Highway

To explore the fatigue damage mechanism and micro-mechanical behavior of the pavement of rubber powder asphalt mixture (ARHM- 20) of expressway influenced by heavy vehicles,a three-dimensional microstructural model of the mixture was built based on the discrete element method,and research on the damage mechanism from aggregate motion to macroscopic permanent deformation were conducted.The Burger's constitutive model was used to characterize the viscoelastic properties of asphalt mortar.The macro mechanical parameters of Burger ’s model at different temperatures were obtained through asphalt creep tests,and the micro modeling parameters were obtained based on the macro and micro conversion formulas.The irregular coarse aggregate was …

Meso-Mechanical Properties Of Bearing Ratio Of Waste Lime‑Fly Ash Macadam And Soil Mixture Based On Discrete Element, Zhang Xiaofei, Chen Yuru, Zhang Song, Gao Lei, Tian Angran, Tang Qiang

Journal of China & Foreign Highway

In the process of applying construction waste to subgrade,the bearing capacity of the material has an important impact on the service performance of roads.In order to evaluate the meso-mechanical properties of construction waste used as subgrade filler,the bearing ratio test of waste lime-fly ash macadam and soil mixture with different stone contents was carried out by using discrete element software.The strength formation mechanism was revealed by using the discrete element method.The results show that the bearing ratio of the mixture increases with the increase in the stone content and reaches the maximum value when the stone content is 80%.In the …

Effect Of Hydrothermal Coupling Aging On Performance Of Rubber Modified Asphalt, Chen Zhenwei, Wu Xuewen, Xiao Xuan, Li Ping, Liu Shende

Journal of China & Foreign Highway

To study the effect of hydrothermal coupling aging on the performance of rubber modified asphalt,this article simulated thermal aging and hydrothermal coupling aging tests and investigated the effect of different aging environments on the high-temperature and low-temperature performance of asphalt from macroscopic and microscopic levels through conventional index tests,dynamic shear rheology tests,and gel chromatography tests,as well as the effect of different aging environments on the interfacial properties through low-temperature adhesion tests of asphalt and aggregates.The results show that the effects of hydrothermal coupling aging on the ductility and softening point of rubber modified asphalt are more significant than those of …

Fatigue Performance Of Qingchuan Rock Modified Asphalt Mixture Under Accelerated Loading Test, Li Zhi, Hao Yan, Yuan Xiaoman, Zhuang Chuanyi

Journal of China & Foreign Highway

To evaluate the fatigue performance of Qingchuan rock modified asphalt mixture,a dynamic wheel-load three-point bending loading fatigue test device based on an accelerated loading test system of 1∶3 scale pavement was designed.The three-point bending repeated loading fatigue test of a composite rutting specimen of double-layer asphalt mixture under tire rolling was carried out.Through the MTS bending fatigue test of a small beam specimen of asphalt mixture,the improvement effects of Qingchuan rock modified asphalt and composite modified asphalt on the fatigue performance of the asphalt mixture were evaluated.The results show that Qingchuan rock modified asphalt can improve the ability of asphalt …