Results 181 to 190 of about 623,991 (302)

Application of regularized covariance matrices in logistic regression and portfolio optimization. [PDF]

Sci Rep
Sun F, Huang X.
europepmc   +1 more source

The Geography of Success: A Spatial Analysis of Export Intensity in the Italian Wine Industry

Agribusiness, EarlyView.
ABSTRACT This paper investigates the paradox of how Italy's fragmented, SME‐dominated wine industry achieves global export success. Moving beyond purely firm‐centric explanations, we test whether export intensity is spatially dependent, clustering geographically in regional ecosystems.
Nicolas Depetris Chauvin, Jonas Di Vita
wiley   +1 more source

Anisotropic local covariance matrices for spatial blind source separation. [PDF]

Adv Stat Anal
Muehlmann C, Cappello C, De Iaco S, Nordhausen K.   +3 more
europepmc   +1 more source

Maximum Covariance Difference Test for Equality of Two Covariance Matrices

, 2007
We propose a test ofeqOIIk y of two covariance matrices based on the maximum standardized di#erence of scalar covariances of two sample covariance matrices.
Akimichi Takemura, Satoshi Kuriki
core  

Is There a Market for Organic Milk in Serbia? Insights From Integrated Choice and Latent Variable Model

Agribusiness, EarlyView.
ABSTRACT Past growth in the global organic market has been concentrated in high‐income countries, while in middle‐income countries such as Serbia the organic market remains nascent and characterized by a sparse assortment of organic products, high retail premia and limited evidence on consumer preferences and their drivers.
Milan Tatic, Sanja Dzever, Bojan Matkovski, Danilo Djokic   +3 more
wiley   +1 more source

Weather Attention in Online Discourse and Price Uncertainty in Agricultural Futures Markets

Agribusiness, EarlyView.
ABSTRACT Weather is a central determinant of production risk in agricultural markets, but markets respond not only to weather conditions themselves, but also to how those conditions are noticed, framed, and interpreted in public discourse. In this setting, real‐time online weather discussions may shape price uncertainty by influencing how market ...
Mario A. Ortez, Olga Isengildina Massa, Michael Liam Smith, Nicole Olynk Widmar   +3 more
wiley   +1 more source

A Class of Structured High-Dimensional Dynamic Covariance Matrices. [PDF]

Commun Math Stat
Yang J, Lian H, Zhang W.
europepmc   +1 more source

Drought Exposure and Dynamic Input Adjustment in North Central U.S. Agriculture

Agribusiness, EarlyView.
ABSTRACT This article examines whether realized extreme drought episodes affect the speed of adjustment of derived input demands and output supplies toward their long‐run equilibrium in U.S. agriculture, focusing on states in the North Central Region.
Victor H. Lana Pinto, Lilyan E. Fulginiti, Richard K. Perrin   +2 more
wiley   +1 more source

Homogeneity tests of covariance matrices with high-dimensional longitudinal data. [PDF]

Biometrika, 2019
Zhong PS, Li R, Santo S.
europepmc   +1 more source

pyDMS: A Python package for the determination of physics‐informed dual‐mode sorption (DMS) parameters

AIChE Journal, EarlyView.
Abstract Sorption in glassy polymer membranes is commonly modeled with the dual‐mode sorption (DMS) model. Fitting the DMS model to sorption isotherms presents challenges, as multiple parameter sets may prove satisfactory. This work presents pyDMS, an open‐source Python package for the computation of DMS parameters obtained via a physics‐informed ...
Brandon C. Tapia, Pablo A. Dean, Jing Ying Yeo, Albert X. Wu, Zachary P. Smith   +4 more
wiley   +1 more source