Numer czasopisma
Opuscula Mathematica
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ISSN: 1232-9274
e-ISSN:
Data wydania
2009
Rocznik
Vol. 29
Numer
No. 3
Prawa dostępu
Dostęp: otwarty dostęp
Uwagi:
Prawa: CC BY 4.0 
Uznanie autorstwa 4.0 Międzynarodowe (CC BY 4.0)
Strony
Opis
Rocznik czasopisma (rel.)
Rocznik czasopisma
Opuscula Mathematica
Vol. 29 (2009)
Artykuły numeru (rel.)
Artykuł
Dostęp ograniczony
On the global offensive alliance number of a tree
(2009) Bouzefrane, Mohamed; Chellali, Mustapha
For a graph [formula], a set [formula] is a dominating set if every vertex in V - S has at least a neighbor in S. A dominating set S is a global offensive alliance if for every vertex v in V - S, at least half of the vertices in its closed neighborhood are in S. The domination number [formula] is the minimum cardinality of a dominating set of G and the global offensive alliance number [formula] is the minimum cardinality of a global offensive alliance of G. We first show that every tree of order at least three with l leaves and s support vertices satisfies [formula] and we characterize extremal trees attaining this lower bound. Then we give a constructive characterization of trees with equal domination and global offensive alliance numbers.
Artykuł
Dostęp ograniczony
Smoothed estimator of the periodic hazard function
(2009) Dudek, Anna
A smoothed estimator of the periodic hazard function is considered and its asymptotic probability distribution and bootstrap simultaneous confidence intervals are derived. Moreover, consistency of the bootstrap method is proved and some applications of the developed theory are presented. The bootstrap method is based on the phase-consistent resampling scheme developed in Dudek and Leśkow [6].
Artykuł
Dostęp ograniczony
Sensitivity analysis in piecewise linear fractional programming problem with non-degenerate optimal solution
(2009) Kheirfam, Behrouz
In this paper, we study how changes in the coefficients of objective function and the right-hand-side vector of constraints of the piecewise linear fractional programming problems affect the non-degenerate optimal solution. We consider separate cases when changes occur in different parts of the problem and derive bounds for each perturbation, while the optimal solution is invariant. We explain that this analysis is a generalization of the sensitivity analysis for LP, LFP and PLP. Finally, the results are described by some numerical examples.
Artykuł
Dostęp ograniczony
Approximation methods for a class of discrete Wiener-Hopf equations
(2009) Nowak, Michał A.
In this paper, we consider approximation methods for operator equations of the form Au + Bu = f, where A is a discrete Wiener-Hopf operator on lp (1 ≤ p < ∞) which symbol has roots on the unit circle with arbitrary multiplicities (not necessary integers). Conditions on perturbation B and f are given in order to guarantee the applicability of projection-iterative methods. Effective error estimates, and simultaneously, decaying properties for solutions are obtained in terms of some smooth spaces. Keywords: projection methods, iterative methods, discrete Wiener-Hopf equations, Toeplitz operators.
Artykuł
Dostęp ograniczony
Monotone iterative technique for fractional differential equations with periodic boundary conditions
(2009) Ramirez, J D; Vatsala, A S
In this paper we develop Monotone Method using upper and lower solutions for fractional differential equations with periodic boundary conditions. Initially we develop a comparison result and prove that the solution of the linear fractional differential equation with periodic boundary condition exists and is unique. Using this we develop iterates which converge uniformly monotonically to minimal and maximal solutions of the nonlinear fractional differential equations with periodic boundary conditions in the weighted norm.
Artykuł
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A note on the maximum likelihood estimator in the gamma regression model
(2009) Rydlewski, Jerzy Piotr
This paper considers a nonlinear regression model, in which the dependent variable has the gamma distribution. A model is considered in which the shape parameter of the random variable is the sum of continuous and algebraically independent functions. The paper proves that there is exactly one maximum likelihood estimator for the gamma regression model.
Artykuł
Dostęp ograniczony
A double index transform with a product of Macdonald's functions revisited
(2009) Âkuboviĉ, Semën B.
We prove an inversion theorem for a double index transform, which is associated with the product of Macdonald's functions [formula], where [formula] and [formula] is a pure imaginary index. The results obtained in the sequel are applied to find particular solutions of integral equations involving the square and the cube of the Macdonald function [formula] as a kernel.