Physical Sciences and Mathematics Commons^™

Generalized Least-Powers Regressions I: Bivariate Regressions, Nataniel Greene

Publications and Research

The bivariate theory of generalized least-squares is extended here to least-powers. The bivariate generalized least-powers problem of order p seeks a line which minimizes the average generalized mean of the absolute pth power deviations between the data and the line. Least-squares regressions utilize second order moments of the data to construct the regression line whereas least-powers regressions use moments of order p to construct the line. The focus is on even values of p, since this case admits analytic solution methods for the regression coefficients. A numerical example shows generalized least-powers methods performing comparably to generalized least-squares methods, …

Implementing Some Basic Simuation Designs Using The Simsem Package In R, Keith A. Markus

Open Educational Resources

The purpose of this tutorial is to provide a very basic introduction to implementing three simple research designs using the simsem package in R. R is an open source statistical computing environment (R Core Team, 2015). For more information about R, see the R Project homepage (https://www.r-project.org/) and the Comprehensive R Archive Network (CRAN) web page (https://cran.r-project.org/). The lavaan package provides functions for fitting and evaluating structural equation models (Rosseel, 2012). For further information about the lavaan package including tutorials, see the lavaan Project web page (http://lavaan.ugent.be/). The simsem package (Pornprasertmanit, Miller & Schoemann, 2016) provides functions to facilitate structural …

Stochastic Processes And Their Applications To Change Point Detection Problems, Heng Yang

Dissertations, Theses, and Capstone Projects

This dissertation addresses the change point detection problem when either the post-change distribution has uncertainty or the post-change distribution is time inhomogeneous. In the case of post-change distribution uncertainty, attention is drawn to the construction of a family of composite stopping times. It is shown that the proposed composite stopping time has third order optimality in the detection problem with Wiener observations and also provides information to distinguish the different values of post-change drift. In the case of post-change distribution uncertainty, a computationally efficient decision rule with low-complexity based on Cumulative Sum (CUSUM) algorithm is also introduced. In the time …

An Early Assessment Of Medium Range Monsoon Precipitation Forecasts From The Latest High-Resolution Ncep-Gfs (T1534) Model Over South Asia, Satya Prakash, Imaranali M. Momin, Ashis K. Mitra, Partha S. Bhattacharjee, Fanglin Yang, Vijay Tallapragada

Publications and Research

Reliable prediction of the South Asian monsoon rainfall and its variability is crucial for various hydrological applications and early warning systems. The National Centers for Environmental Prediction – Global Forecast System (NCEP–GFS) is one of the popular global deterministic numerical weather prediction models, which is recently upgraded from T574 to T1534. In this paper, medium range monsoon precipitation forecasts from both the T1534 and T574 models are critically evaluated over the South Asia for the peak monsoon months (July and August) of 2015. Although both the versions of GFS model show similar large-scale monsoon rainfall patterns, the dry bias over …

Quantifying Transit Access In New York City: Formulating An Accessibility Index For Analyzing Spatial And Social Patterns Of Public Transportation, Maxwell S. Siegel

Theses and Dissertations

This paper aims to analyze accessibility within New York City’s transportation system through creating unique accessibility indices. Indices are detailed and implemented using GIS, analyzing the distribution of transit need and access. Regression analyses are performed highlighting relationships between demographics and accessibility and recommendations for transit expansion are presented.

Multilevel Analysis Of Individual, Neighborhood, And Health Care Facility Characteristics Associated With Achievement And Maintenance Of Hiv Viral Suppression Among Persons Newly Diagnosed With Hiv In New York City, Ellen W. Wiewel

Dissertations, Theses, and Capstone Projects

Objective

To investigate the effect of individual, health care facility, and neighborhood characteristics on achievement and maintenance of HIV viral suppression, among New York City residents aged 13 years and older diagnosed with HIV between 2006 and 2012.

Methods

I used individual-level data from the New York City HIV surveillance registry and Case Surveillance-Based Sampling, facility-level data from the surveillance registry, and neighborhood-level data from the U.S. Census and American Community Survey. The outcomes of interest were first viral suppression after diagnosis (Aims 1 and 3; ≤400 copies/mL) and virologic failure after first suppression among persons who achieved suppression (Aim …

A Preliminary Assessment Of Gpm-Based Multi-Satellite Precipitation Estimates Over A Monsoon Dominated Region, Satya Prakash, Ashis K. Mitra, Amir Aghakouchak, Zhong Liu, Hamidreza Norouzi, D. S. Pai

Publications and Research

Following the launch of the Global Precipitation Measurement (GPM) Core Observatory, two advanced high resolution multi-satellite precipitation products namely, Integrated Multi-satellitE Retrievals for GPM (IMERG) and Global Satellite Mapping of Precipitation (GSMaP) version 6 are released. A critical evaluation of these newly released precipitation data sets is very important for both the end users and data developers. This study provides a comprehensive assessment of IMERG research product and GSMaP estimates over India at a daily scale for the southwest monsoon season (June to September 2014). The GPM-based precipitation products are inter-compared with widely used TRMM Multi-satellite Precipitation Analysis (TMPA), and …