Marina Tošić

University of Pristina

This manuscript deals with a parameter estimation of a non-negative integer-valued (NNIV) time series based on the so-called probability generating function (PGF) method. The theoretical background of the PGF estimation technique for a very general, stationary class of NNIV time series is described, as well as the asymptotic properties of the obtai...

The paper emphasizes various aspects of mathematical games usage in mathematics instruction. Different mathematical games are discussed in accordance to the Principles of educationally-rich mathematical games. Two of them-Bingo and Tangram-are included in a primary school mathematics instruction and their impact in the instruction was assessed. The...

The main purpose of this paper is to improve, generalize, unify, extend and enrich the recent results established by N.V. Dung, V.I. Hang [N.V. Dung, V.I. Hang, A fixed point theorem3 for generalized F-contractions on complete metric spaces, Vietnam J. Math. 43, 743-753 (2015).], H.Piri and P. Kumam [H. Piri and P. Kumam, Some fixed point theorems...

The repair rate is a very important parameter for system maintainability and can be defined as a frequency of successfully performed repair actions on a failed component per unit of time. This paper analyzes the integral characteristics of a stochastic repair rate for corresponding values of availability in a system operating under maintenance cont...

In this paper, the application of homotopy perturbations method (HPM) in approximation the probability distribution of some non-linear stochastic models that have probability densities functions (PDFs) with no closed form is described. The main result is based on HPM approximations the PDFs of some non-linear autoregressive time series, which are w...

Repair rate is very important parameter in a system maintainability and it can be defined as frequency of the successfully performed repair actions on failed component per unit of time. This paper analyses the integral characteristics of a stochastic repair rate for corresponding values of availability in the system operating under maintenance cont...

Baksalary et al. (Linear Algebra Appl., doi:10.1016/j.laa.2004.02.025, 2004) investigated the invertibility of a linear combination of idempotent matrices. This result was improved by Koliha et al. (Linear Algebra Appl., doi:10.1016/j.laa.2006.01.011, 2006) by showing that the rank of a linear combination of two idempotents is constant. In this pap...

The aim of this paper is to give alternate representations of the Moore-Penrose inverse of a linear combination of generalized and hypergeneralized projectors and to provide alternate proofs of the invertibility of some linear combination of commuting generalized and hypergeneralized projectors.

In this paper we give a representation of the Moore-Penrose inverse and the group inverse of a linear combination of Moore-Penrose Hermitian matrices, i.e., square matrices satisfying A⁺ = A. Also, we consider the invertibility of some linear combination of commuting Moore-Penrose Hermitian matrices.

We consider the problem of characterizing situations where a linear combination of commuting involutive matrices is a k-potent matrix, where k is a positive integer such that k⩾2k⩾2. Also, we consider the problem of characterizing situations where a linear combination of the form c1In+c2A+c3Bc1In+c2A+c3B is a nonsingular or an involutive matrix, wh...

We characterize hypergeneralized k-projectors (i.e., ). Also, some representation for the Moore-Penrose inverse of a linear combination of hypergeneralized k-projectors is found and the invertibility for some linear combinations of commuting hypergeneralized k-projectors is considered.

In this paper, we present some results relating different matrix partial orderings and the invertibility of a linear combination of EP matrices.

In this article, we study necessary and sufficient conditions for the invertibility of a linear combination c1A + c2B , in the case when A and B are both commuting generalized or hypergeneralized projectors. We present some results relating different matrix partial orderings and the invertibility of a linear combination c1A + c2B when A and B are h...

Some representations for the Moore-Penrose inverse of a linear combination of generalized and hypergeneralized projectors are found. Also, the invertibility for some linear combinations of commuting generalized and hypergeneralized projectors is considered.