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Full-Text Articles in Physical Sciences and Mathematics

Generalized Least-Powers Regressions I: Bivariate Regressions, Nataniel Greene Nov 2016

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 Sep 2016

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 …


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 Jun 2016

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 …


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 Jan 2016

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 …