Abstract The primary objective of the study was determination spatial and multiannual variability occurrence days with very strong extreme cold stress in Poland according to Universal Thermal Climate Index (UTCI), as well baric conditions favouring their occurrence. based on data from years 1966/67 2018/19 Institute Meteorology Water Management – National Research Centre for Environmental Predi...

Generalised halfspace depth function is proposed. Basic properties of this depth function including the strong consistency are studied. We show, on several examples that our depth function may be considered to be more appropriate for nonsymetric distributions or for mixtures of distributions.

For any simple connected graph $G=(V,E)$, a defensive alliance is a subset $S$ of $V$ satisfying the condition that every vertex $vin S$ has at most one more neighbour in $V-S$ than it has in $S$. The minimum cardinality of any defensive alliance in $G$ is called the alliance number of $G$, denoted $a(G)$. In this paper, we introduce a new type of alliance number called $k$-strong alliance numb...

The paper deals with the best unbiased estimators of the blocked compound symmetric covariance structure for m−variate observations over u sites under the assumption of multivariate normality. The free-coordinate approach is used to prove that the quadratic estimation of covariance parameters is equivalent to linear estimation with a properly defined inner product in the space of symmetric matr...