An association scheme is amorphous if it has as many fusion schemes as possible. Symmetric amorphous schemes were classified by A. V. Ivanov [A. V. Ivanov, Amorphous cellular rings II, in Investigations in algebraic theory of combinatorial objects, pages 39–49. VNIISI, Moscow, Institute for System Studies, 1985] and commutative amorphous schemes were classified by T. Ito, A. Munemasa and M. Yam...

We consider regularization of the parameters in multivariate linear regression models with the errors having a multivariate skew-t distribution. An iterative penalized likelihood procedure is proposed for constructing sparse estimators of both the regression coefficient and inverse scale matrices simultaneously. The sparsity is introduced through penalizing the negative log-likelihood by adding...

Consider options on a nonnegative underlying random variable with arbitrary distribution. In the absence of arbitrage, we show that at any maturity T , the large-strike tail of the Black-Scholes implied volatility skew is bounded by the square root of 2|x|/T , where x is log-moneyness. The smallest coefficient that can replace the 2 depends only on the number of finite moments in the underlying...

Let T = [0, 1) be the additive group of real numbers modulo 1, α ∈ T be an irrational number and t ∈ T. We consider skew product extensions of irrational rotations by Z 2 determined by T : T × Z 2 → T × Z 2 T (x, s 1 , s 2) = " x + α, s 1 + 2χ [0, 1 2) (x) − 1, s 2 + 2χ [0, 1 2) (x + t) − 1 «. We study ergodic components of such extensions and use the results to display irregularities in the un...

Abstract In this note, we provide a short proof of Theorem 4.3 in the paper titled Crystals, semistandard tableaux and cyclic sieving phenomenon , by Y.-T. Oh E. Park, which concerns on semi-standard Young tableaux. We also extend their result to skew shapes.

In this paper, likelihood-based inference and bias correction based on Firth’s approach are developed in the modified skew-t-normal (MStN) distribution. The latter model exhibits a greater flexibility than skew-normal (MSN) distribution since it is able to heavily skewed data thick tails. addition, tails controlled by shape parameter degrees of freedom. We provide density new present some its m...

Normalization of restricted T-cell–receptor (TCR) repertoire is critical following T-cell–depleted (TCD) stem cell transplantation. We present a prospective study analyzing respective contributions of naive and memory T-cell subsets within the CD4 and CD8 compartments to the evolution of overall TCR-repertoire complexity following transplantation of CD34selected peripheral blood progenitor cell...

This article examines annihilators in the skew polynomial ring $R[x;alpha,delta]$. A ring is strongly right $AB$ if everynon-zero right annihilator is bounded. In this paper, we introduce and investigate a particular class of McCoy rings which satisfy Property ($A$) and the conditions asked by P.P. Nielsen. We assume that $R$ is an ($alpha$,$delta$)-compatible ring, and prove that, if $R$ is ni...

In this paper, a three dimensional analysis of arbitrary straight-sided quadrilateral nanocomposite plates are investigated. The governing equations are based on three-dimensional elasticity theory which can be used for both thin and thick nanocomposite plates. Although the equations can support all the arbitrary straight-sided quadrilateral plates but as a special case, the numerical results f...