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Some results on multivariate measures of elliptical and skew-elliptical distributions: higher-order moments, skewness and kurtosis
AIMS Mathematics 2023, 8(3): 7346-7376
Published: 15 March 2023
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The kurtosis and skewness of distributions are important measures that can describe the shape of a distribution, and there have been many results for symmetric distributions, but there are still many difficulties and challenges in the characterization of skew distributions. Based on the results of Mardia's and Song's kurtosis measures of elliptical distributions obtained by Zografos [1], we generalize the results and study some measures for elliptical and skew-elliptical distributions. We also derive the expressions of moments of skew-elliptical distributions in terms of the ones of skew-normals and take skew- t, skew-Pearson type Ⅶ and skew-Pearson type Ⅱ distributions as examples.

Open Access Research Article Issue
Tail risk measures with application for mixtures of elliptical distributions
AIMS Mathematics 2022, 7(5): 8802-8821
Published: 15 May 2022
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In this paper we derive explicit formulas of tail conditional expectation ( TCE) and tail variance ( TV) for the class of location-scale mixtures of elliptical distributions, which includes the generalized hyper-elliptical ( GHE) distribution. We also develop portfolio risk decomposition with TCE for multivariate location-scale mixtures of elliptical distributions. To illustrate our findings, we focus on the generalized hyperbolic ( GH) family which is a popular subclass of the GHE for stocks modelling.

Open Access Research Article Issue
Some stochastic orderings of multivariate skew-normal random vectors
AIMS Mathematics 2023, 8(10): 23427-23441
Published: 15 October 2023
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In this paper, we investigate some multivariate integral stochastic orderings of skew-normal random vectors. We derive the results of the sufficient and/or necessary conditions by applying an identity for E f ( Y ) E f ( X ), where X and Y are multivariate skew-normal random vectors, f satisfies some weak regularity condition. The integral orders considered here are the componentwise convex, copositive, completely-positive orderings and their corresponding increasing ones as well as linear forms of stochastic orderings, which play a vital role in transforming the unmanageable multivariate components into an easy-to-handle univariate variable.

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