Search results for "HA1-4737"

bookdown: Authoring Books and Technical Documents with R Markdown

2018

Determinantes Políticos de las Transferencias Discrecionales. Evidencia de la Provincia de Córdoba, Argentina

2005

Este trabajo examina el impacto de la táctica política en la distribución de las transferencias de fondos discrecionales entre el gobierno provincial y los municipios. Se analizan las diferentes teorías basadas en modelos partidistas y no partidistas, contrastando las mismas empíricamente para los municipios de la provincia de Córdoba, en Argentina. Los resultados obtenidos permiten confirmar la existencia de factores políticos y económicos como determinantes de la asignación de las transferencias discrecionales y si bien ninguno de los modelos teóricos explicados se ven reflejados en sentido estricto, sí se observa una combinación entre ellos. This work examines the impact of political tac…

Mixture Hidden Markov Models for Sequence Data: The seqHMM Package in R

2019

Sequence analysis is being more and more widely used for the analysis of social sequences and other multivariate categorical time series data. However, it is often complex to describe, visualize, and compare large sequence data, especially when there are multiple parallel sequences per subject. Hidden (latent) Markov models (HMMs) are able to detect underlying latent structures and they can be used in various longitudinal settings: to account for measurement error, to detect unobservable states, or to compress information across several types of observations. Extending to mixture hidden Markov models (MHMMs) allows clustering data into homogeneous subsets, with or without external covariate…

KFAS : Exponential Family State Space Models in R

2017

State space modelling is an efficient and flexible method for statistical inference of a broad class of time series and other data. This paper describes an R package KFAS for state space modelling with the observations from an exponential family, namely Gaussian, Poisson, binomial, negative binomial and gamma distributions. After introducing the basic theory behind Gaussian and non-Gaussian state space models, an illustrative example of Poisson time series forecasting is provided. Finally, a comparison to alternative R packages suitable for non-Gaussian time series modelling is presented.

Graphical User Interfaces for R

2012

Since R was first launched, it has managed to gain the support of an ever-increasing percentage of academic and professional statisticians. However, the spread of its use among novice and occasional users of statistics have not progressed at the same pace, which can be attributed partially to the lack of a graphical user interface (GUI). Nevertheless, this situation has changed in the last years and there is currently several projects that have added GUIs to R. This article discusses briefly the history of GUIs for data analysis and then introduces the papers submitted to an special issue of the Journal of Statistical Software on GUIs for R.

The Effect of Education on Under-Five Mortality: Individual and Community-Level Effects in Bangladesh

2019

This paper investigates the relationship between parental education and child survival, considering both the influence of the maternal and paternal educational level and the influence of communitylevel male and female education on under-five mortality. The research is focused on Bangladesh, a country where the impressive decline in the under-five mortality rate between 1990 and 2015 was attributed both to female empowerment and to the increase in the general level of education in the country. Using the Bangladesh Demographic and Health Survey from 2014, this paper investigates both the effect of individual-level parental education and of community-level education on under-five mortality, th…

Some issues concerning the statistical evaluation of a screening test: the ARFI ultrasound case

2013

In this paper we analyze some issues concerning the statistical evaluation of a screening test for classification. The case study is ARFI, an ultrasound device recently introduced, and used for the evaluation of liver fibrosis. First, we present a simple statistical evaluation based on a novel index that compare two competitors with respect to a gold standard, and then we propose a procedure that determines a table with the “acceptable” number of measurements to get an “accurate” diagnosis using the ARFI device.

On Independent Component Analysis with Stochastic Volatility Models

2017

Consider a multivariate time series where each component series is assumed to be a linear mixture of latent mutually independent stationary time series. Classical independent component analysis (ICA) tools, such as fastICA, are often used to extract latent series, but they don't utilize any information on temporal dependence. Also financial time series often have periods of low and high volatility. In such settings second order source separation methods, such as SOBI, fail. We review here some classical methods used for time series with stochastic volatility, and suggest modifications of them by proposing a family of vSOBI estimators. These estimators use different nonlinearity functions to…

Blind Source Separation Based on Joint Diagonalization in R: The Packages JADE and BSSasymp

2017

Blind source separation (BSS) is a well-known signal processing tool which is used to solve practical data analysis problems in various fields of science. In BSS, we assume that the observed data consists of linear mixtures of latent variables. The mixing system and the distributions of the latent variables are unknown. The aim is to find an estimate of an unmixing matrix which then transforms the observed data back to latent sources. In this paper we present the R packages JADE and BSSasymp. The package JADE offers several BSS methods which are based on joint diagonalization. Package BSSasymp contains functions for computing the asymptotic covariance matrices as well as their data-based es…

Anthropometry: An R Package for Analysis of Anthropometric Data

2017

The development of powerful new 3D scanning techniques has enabled the generation of large up-to-date anthropometric databases which provide highly valued data to improve the ergonomic design of products adapted to the user population. As a consequence, Ergonomics and Anthropometry are two increasingly quantitative fields, so advanced statistical methodologies and modern software tools are required to get the maximum benefit from anthropometric data. This paper presents a new R package, called Anthropometry, which is available on the Comprehensive R Archive Network. It brings together some statistical methodologies concerning clustering, statistical shape analysis, statistical archetypal an…