Proving the convergence of the iterative methods by using symbolic
computation in Maple

Author: Gheorghe Ardelean

Abstract: The proofs of the convergence for some high-order methods
for solving nonlinear equations, by using symbolic computation in Maple, is presented.
Also, the convergence error for some Newton-type methods is evaluated by symbolic computation. PDF |

No. of downloads: 345

Some hyperbolic concurrency results in the Poincare disc

Author: Cătălin Barbu / Laurian-Ioan Pișcoran

Abstract: In this paper, we present a proof of some hyperbolic theorems in the Poincare Model of Hyperbolic Geometry. PDF |

No. of downloads: 231

On the eta -(1,2) approximated optimization problems

A general fixed point method for the stability of the monomial functional equation

Author: Liviu Cădariu / Viorel Radu

Abstract: In this paper, we extend the ideas in [CÄƒdariu, L. and Radu, V., A general fixed point method for the stability of Jensen functional equation,
Bull. Åžt. Univ. Politehnica TimiÅŸoara, Ser. Mat.-Fiz. 51(65) (2006), No. 2, 63--72] to obtain some general stability results for monomial functional equations in $\beta-$normed spaces. The fixed point alternative together the error estimations for generalized
contractions of type Bianchini-Grandolfi are pointed out, and then used as fundamental tool. Some applications and examples which emphasize the very general hypotheses, are also given. PDF |

No. of downloads: 215

Optimization problems and (0,2)-eta-approximated optimization problems

A sequential algorithm for finding the solution of the parametric minimum flow problem

Author: Eleonor Ciurea / Mircea Parpalea

Abstract: This article presents a sequential approach for the parametric minimum flow problem. It consists in repeatedly applying a non parametric maximum flow algorithm in a modified network for a sequence of parameter values in an increasing order. The algorithm computes an initial minimum flow for a given fixed value of the parameter and then repeatedly finds a maximum flow by which the flow can be decreased over the next interval of the parameter values so that the maximum cut not to change. This maximum flow is computed as a maximum flow problem in a modified network with properly set lower and upper bounds. On each of the iterations, the algorithm computes a new breakpoint of the piecewise linear minimum flow value function and the corresponding parametric minimum flow. PDF |

On the Hyers-Ulam stability of a first order partial differential equation

Author: Nicolaie Lungu / Dorian Popa

Abstract: We obtain a result on Hyers-Ulam stability for a linear partial differential equation
of order one in a Banach space. PDF |

No. of downloads: 176

Double condensation of singularities for product-quadrature formulas with differentiable functions

Author: Alexandru I. Mitrea

Abstract: The main goal of this paper is to emphasize the phenomenon of double condensation of singularities
for spaces of differentiable functions with respect to product-quadrature formulas
associated to a class of node triangular matrices in [-1,1], including
a Gegenbauer node matrix and the matrix of equidistant nodes in [-1,1]. PDF |

No. of downloads: 241

Gamma function estimates via completely monotonicity arguments

Author: Cristinel Mortici

Abstract: The aim of this paper is to improve some recent results of Sandor and Debnath [On certain inequalities involving the constant e and their applications J. Math. Anal. Appl. 249 (2000) 569-582] and Batir [Sharp inequalities for factorial n Proyecciones 27 (2008) 97-102] about the problem of approximation of gamma function. In proving the results in this paper, the proofs are not completely analytic but essentially based on formal computations obtained by means of software packages. PDF |

No. of downloads: 206

Tonelli's Lemma and applications

Author: Anton S. Mureșan

Abstract: In this paper we give some applications of Tonelli's Lemma to the separation of the zeros of the solutions of some functional differential equations PDF |

No. of downloads: 163

On the solutions of a second order functional-differential equation

Common fixed points for almost Presic type operators

Author: Mădălina Păcurar

Abstract: The existence of coincidence points and common fixed points for almost Presic operators in a metric space setting is proved. A multi-step iterative method for constructing the common fixed points is also provided. PDF |

New models of the generalized fixed-charge network design problem

Author: Petrică Claudiu Pop / Corina Pop Sitar

Abstract: We consider in this paper the generalized fixed-charge network design (GFCND) problem in which we are interested to find the cheapest backbone network connecting exactly one hub from each of the given clusters. The GFCND problem belongs to the class of generalized combinatorial optimization problems.
We describe two mixed integer programming formulations of the GFCND problem. Based on one of the new proposed formulations, we solve the GFCND problem to optimality using CPLEX for problems with up to 30 clusters and 200 nodes. Computational results are reported and compared with those from the literature. PDF |

No. of downloads: 140

Stability of some functional equations defined by quasiarithmetic means

Author: Vasile Pop

Abstract: We obtain results on Hyers-Ulam stability for some functional equations defined
by quasiarithmetic means. PDF |

No. of downloads: 201

Estimates for the semigroup associated with Bernstein-Schnabl operators

Existence results for three-point boundary value
problems for systems of linear functional differential equations

Author: A. Ronto / M. Ronto

Abstract: Conditions guaranteeing the solvability of certain
three-point boundary value problems for a system of linear
functional differential equations are obtained by using a special
successive approximation scheme. We also
establish some conditions necessary for a certain set belonging to
the domain of the space variables to contain a point determining
the initial value of the solution. An algorithm for
selecting such points is also indicated. PDF |