The surface affinity of the hydronium ion in water is investigated with umbrella sampling and classical molecular dynamics simulations, in which the system is described with the effective fragment potential (EFP). The solvated hydronium ion is also explored using second order perturbation theory for the hydronium ion and the empirical TIP5P potential for the waters. Umbrella sampling is used to...

Designing an efficient sampling scheme for a rare and clustered population is a challenging area of research. Adaptive cluster sampling, which has been shown to be viable for such a population, is based on sampling a neighborhood of units around a unit that meets a specified condition. However, the edge units produced by sampling neighborhoods have proven to limit the efficiency and applicabili...

THE EFFECT OF NONRANDOM SELECTION OF CLUSTERS IN A TWO STAGECLUSTER DESIGN byJASON PARROTTDecember 2012Advisor: Dr. Shlomo SawilowskyMajor: Evaluation and ResearchDegree: Doctor of Philosophy Although not as efficient as simple random sampling, cluster sampling has beenregarded as a valid sampling technique when the researcher is attempting to save cost. However,...

Abstract Survey data are often collected under multistage sampling designs where units binned to clusters that sampled in a first stage. The unit-indexed population variables of interest typically dependent within cluster. We propose Fully Bayesian method constructs an exact likelihood for the observed sample incorporate unit-level marginal weights performing unbiased inference parameters while...

To estimate the variance for rare and cluster population has been main problemin survey sampling. Three ratio type estimators were proposed utilizing thesingle auxiliary variable assuming transformed adaptive sampling, inpresented study. The expressions mean square error bias of estimator werederived. estimatorswere used to finite in adaptivecluster simulationswereperformedon a real life data r...