Results 71 to 80 of about 23,045 (305)

A block EM algorithm for multivariate skew normal and skew t-mixture models

IEEE transactions on neural networks and learning systems, 2016
Finite mixtures of skew distributions provide a flexible tool for modelling heterogeneous data with asymmetric distributional features. However, parameter estimation via the Expectation-Maximization (EM) algorithm can become very time-consuming due to the complicated expressions involved in the E-step that are numerically expensive to evaluate.
Sharon X. Lee, Kaleb L. Leemaqz, Geoffrey J. McLachlan   +2 more
openaire   +5 more sources

Limit distributions for Mardia\u27s measure of multivariate skewness

, 2008
We study the asymptotic behavior of Mardia\u27s measure of (sample) multivariate skewness. In the special case of an elliptically symmetric distribution, the limit law is a weighted sum of two independent χ$^2$-variates.
Baringhaus, Ludwig, Henze, Norbert
core   +1 more source

Electrocardiographic and Skin Manifestations of Turner Syndrome: Association With Cardiovascular Disease

American Journal of Medical Genetics Part A, EarlyView.
ABSTRACT Congenital heart disease (CHD) and dermatologic conditions such as lymphedema and acquired melanocytic nevi (AMN) are common in Turner Syndrome (TS). We hypothesized that abnormalities of cranial neural crest cell derivatives drive the skin and heart manifestations of TS. We conducted joint cardiac and skin examinations of volunteers at a 2023
Sarah Elsaim, Brett Vernier, Van Thi Thanh Truong, Riya T. Patel, Matthew Brown, Martin Chacon Portillo, Megan Rogge, David Rodriguez‐Buritica, Siddharth K. Prakash   +8 more
wiley   +1 more source

Cortical bone distribution in the human mandibular symphysis: Ontogenic and morphometric approaches in archeological context

The Anatomical Record, EarlyView.
Abstract The human mandibular symphysis concentrates multiaxial loads during function and remodels throughout growth, but the precise mechanisms underlying cortical bone shape during growth remain relatively unexplored. Approaches based solely on thickness or external cortical contours provide only partial insights and do not capture the functional ...
Ana Ribeiro, Elsa Garot, Christine Couture, Pierre‐Hadrien Decaup   +3 more
wiley   +1 more source

CircNNTSR: An R Package for the Statistical Analysis of Circular, Multivariate Circular, and Spherical Data Using Nonnegative Trigonometric Sums

Journal of Statistical Software, 2016
The statistical analysis of circular, multivariate circular, and spherical data is very important in different areas, such as paleomagnetism, astronomy and biology.
Juan José Fernández-Durán, María Mercedes Gregorio-Domínguez   +1 more
doaj   +1 more source

On Describing Multivariate Skewness: A Directional Approach [PDF]

Most multivariate measures of skewness in the literature measure the overall skewness of a distribution. While these measures are perfectly adequate for testing the hypothesis of distributional symmetry, their relevance for describing skewed ...
J. T. A. S. Ferreira, M. F. J. Steel
core  

Multivariate skewness and kurtosis measures with an application in ICA

, 2008
In this paper skewness and kurtosis characteristics of a multivariate p-dimensional distribution are introduced. The skewness measure is defined as a p-vector while the kurtosis is characterized by a p×p-matrix.
Kollo, Tõnu
core   +1 more source

Pelvic morphology and body size in relation to the preauricular sulcus: Evidence from medieval to modern Iberia

The Anatomical Record, EarlyView.
Abstract The preauricular sulcus has long been debated as a pelvic feature variably attributed to obstetric stress, ligamentous traction, and broader biomechanical processes. To clarify its determinants, we analyzed 409 adult individuals from three archeological and one early modern skeletal collection from the Iberian Peninsula, integrating graded ...
Rebeca García‐González, Julia Muñoz‐Guarinos, Nico Cirotto, Sonia Díaz‐Navarro, Laura Rodríguez, José Miguel Carretero   +5 more
wiley   +1 more source

Evaluating Agreement Among Multiple Methods With Replicated Measurements Using Scale Mixtures of Skew-Normal Measurement Error Models

Journal of Probability and Statistics
This paper introduces a robust parametric approach for assessing the agreement among multiple measurement methods when dealing with replicated data from a continuous variable.
Jeevana Duwarahan, Lakshika S. Nawarathna   +1 more
doaj   +1 more source

Model Comparison of Coordinate-Free Multivariate Skewed Distributions with an Application to Stochastic Frontiers [PDF]

We consider classes of multivariate distributions which can model skewness and are closed under orthogonal transformations. We review two classes of such distributions proposed in the literature and focus our attention on a particular, yet quite flexible,
Jose T.A.S. Ferreira, Mark F.J. Steel
core