Volume 21, No. 1 (2011)
Articles
THE MEAN VALUE THEOREMS AND INEQUALITIES OF OSTROWSKI TYPE
ANA MARIA ACU(1), ALINA BABOŞ(2), FLORIN SOFONEA(3)
The main purpose of this paper is to derive new inequalities of Ostrowski type using mean value theorems. The inequalities for p-norm are also given and the weighted case is considered. New estimations of the remainder term in quadrature formulas are obtained.
NORMAL APPROXIMATIONS OF GEODESICS ON SMOOTH TRIANGULATED SURFACES
ELI APPLEBOIM(1), EMIL SAUCAN(2)
In this paper we study relations between normal curves and geodesic curves on triangulated smooth surfaces. Based on a curvature measure for normal curves, we define normal geodesics and build a semi discrete curvature flow under which normal geodesics converge to classical geodesic curves and vice versa, each geodesic in the classic differential geometric sense can be approximated by a sequence of normal geodesics under the defined flow. We give experimental results for the approximation of geodesics on both synthetic as well as on meshes generated from point clouds obtained by sampling of real data.
ON A ONE-DIMENSIONAL MATHEMATICAL MODEL RELATED TO SOIL BIOREMEDIATION
ELENA- ROXANA ARDELEANU
In this paper we present a mathematical model associated to a bioremediation process. We consider a one-dimensional soil composed of a single layer. In this bioremediation process the bacteria migrates by diffusion and chemotaxis, where the diffusion coefficient is supposed to be constant. The mathematical model is given by a system of nonlinear partial differential equations. In order to study this system of equations, we use the perturbation method for small parameters. The existence and uniqueness of the solution is studied within the framework of the equations` evolution theory based on m-accretive operators.
STRONGLY PROJECT-ORIENTED LEARNING SYSTEMS. CONCEPTS AND FUNDAMENTAL PRINCIPLES
DORIN BOCU(1), RĂZVAN BOCU(2)
The main idea of the paper: The success of a certain learning system heavily relies on the quality of the communication. The complementary idea of the paper: A learning system is efficient provided its activities are organized around certain projects. Not the learning process seen as a goal by itself will bring the educational system at the frontline of knowledge, but projects, on the occasion of which teachers together with pupils or students, solve the society's problems in a natural manner.
SLIGHTLY CONTINUOUS FUZZY MULTIFUNCTIONS IN MINIMAL STRUCTURES
MIHAI BRESCAN
In this paper we introduce the class of slightly m-continuous fuzzy multifunctions, which is a generalization of the concept called a slightly m-continuous multifunction introduced by Valeriu Popa and Takashi Noiri in the general topology ([7]). At the same time we introduce the concept of fuzzy generalized multifunction and we investigate the properties.
APPROXIMATION OF FRACTALS GENERATED BY INTEGRAL OPERATORS
ION CHIŢESCU(1), HORIA GEORGESCU(2), RADU MICULESCU(3)
We present some results concerning fractals generated by an iterated function system which is formed using integral operators on the infinite dimensional space of continuous functions on a compact interval. We approximate the fractal via a finite approximant set and project this approximant set in two dimensions, in order to make possible the visualization of the fractal.
BIMETRIC SPACES, SPACE-TIME AND MATHEMATICS. METHODOLOGICAL PROBLEMS
MITROFAN M. CIOBAN(1), ION I. VALUŢĂ(2)
The development of the geometry is inseparably linked with the history of the development of the mathematics which may be divided into seven periods. The concept of a bimetric space is introduced and studied. This notion is applied to construction of some new models of the space-time.
MULTIPLE SOLUTIONS FOR A CLASS OF NONLINEAR EQUATIONS VIA THE MOUNTAIN PASS THEOREM
JENICĂ CRÎNGANU
The aim of this paper is to study the existence of the multiple solutions for the abstract equation Jp u=Nf u, where Jp is the duality mapping on a real reflexive and smooth Banach space X, corresponding to the gauge function φ(t)=tp-1, 1
A HYBRID TECHNIQUE FOR A MATRIX BANDWIDTH PROBLEM
GLORIA CERASELA CRIŞAN(1), CAMELIA-M. PINTEA(2)
The Combinatorial Optimization Problems have today many complex real-life instances; even using extensive computing resources, their large dimensions and difficult constraints make the exact solving methods to be inappropriate. This is why heuristic methods are used in order to quickly obtain very good solutions. Here we propose a hybrid heuristic method for the Matrix Bandwidth Minimization Problem, based on an Ant Colony Optimization method and several local-search mechanisms. This well-known NP-complete problem refers to finding a permutation of the rows and columns of a sparse symmetric matrix in order to minimize its bandwidth for the nonzero entries. The Matrix Bandwidth Minimization Problem has broad applications in science, logistics or engineering.
A DEFORMATION OF A QUARTIC CARTAN METRIC
OTILIA LUNGU
In this paper we consider a Cartan space Cn=(M,K(x,p)) with the metric K(x,p)=(aijkh(x)pipjpkph)1/4 and a deformation using ω(x,p)=bi(x)pi. We call it a Randers- Quartic Cartan space and we are going to study some of its properties
INDEPENDENCE POLYNOMIALS OF SOME GRAPHS WITH EXTREMAL FIBONACCI INDEX
EUGEN MANDRESCU(1), ION MIRICA(2)
An independent set in a graph G is a set of pairwise non-adjacent vertices, and the independence number α(G) is the cardinality of a maximum stable set in G. The independence polynomial of G is I(G;x)=s0+s1x+s2x2+...+sαxα, α=α(G), where sk is the number of independent sets of size k in G (I. Gutman and F. Harary, 1983). The Fibonacci index Fib(G) of a graph G is the number of all its independent sets, i.e., Fib(G)=I( G;1). Tight lower and upper bounds for Fibonacci index are known for general graphs, connected or not, and the corresponding extremal graphs are characterized [6], [15]. In this paper, we give explicit formulae for independence polynomials of these extremal graphs, which we further use to analyze some of their properties (unimodality, log-concavity).
MYLLER CONFIGURATIONS AND VRĂNCEANU NONHOLONOMIC MANIFOLDS
RADU MIRON
One studies the relations between Myller Configurations and Vrănceanu Nonholonomic Manifolds.
THREE EXTENSIONS OF ORLICZ-SOBOLEV SPACES TO METRIC MEASURE SPACES AND THEIR MUTUAL EMBEDDINGS
MARCELINA MOCANU
We study the mutual embeddings between three extensions of Orlicz-Sobolev spaces to a metric measure space, the Orlicz-Sobolev spaces of Newtonian type, of Hajlasz type and of Cheeger type.
ON THE STATISTICAL APPROXIMATION PROPERTIES OF Q-SCHURER OPERATORS
CARMEN VIOLETA MURARU(1), VALER NIMINEŢ(2)
The results from q-Calculus theory occurs in many applications from physics, quantum theory, number theory, etc. The aim of this paper is to study some convergence properties of q-Schurer operators, in terms of statistical approximation.
ON THE APPROACHES OF CLASSICAL ARTIFICIAL INTELLIGENCE AND EMBODIED ARTIFICIAL INTELLIGENCE
ELENA NECHITA
The paper presents some key concepts of Embodied Artificial Intelligence (EAI) and their contrast to the classic, earlier Artificial Intelligence (AI) paradigms. Considering its strengths and weaknesses, we review some results of this approach, in order to conclude if EAI can further our understanding of intelligence.
SUB-RIEMANNIAN STRUCTURES ASSOCIATED WITH A GENERALIZED LAGRANGE METRIC
VALER NIMINEŢ(1), CARMEN VIOLETA MURARU(2)
We continue the investigations of GL-space with the study of sub-Riemannian structures which can be geometrically associated to a generalized Lagrange metric.
BIO-INSPIRED COMPONENTS FOR A BANDWIDTH PROBLEM
CAMELIA-M. PINTEA(1), ANDREEA VEŞCAN(2)
In this paper are illustrated some specific bio-inspired component for solving a combinatorial optimization problem: The Matrix Bandwidth Minimization Problem(MBMP). The described components are based on a hybrid model of the Ant Colony System technique with new local search mechanisms [4]. MBMP seeks for a simultaneous permutation of the rows and also of the columns of a square matrix in order to keep its nonzero entries close to the main diagonal.
ADAPTABLE SOFTWARE - MODULAR EXTENSIBLE MONADIC ENTRY-POINTLESS TYPE CHECKER IN HASKELL
DAN POPA
The goal of this paper is to investigate the use of a software technology – the pseudoconstructors over monadic values (structures capable of simultaneously representing both syntax and semantics) – to build modular entry-pointless type checkers using the VHLL Haskell. A template used by almost all the modules of the modular monadic entry-pointless type checker is also revealed.
A GENERAL FIXED POINT THEOREM FOR SEVERAL MAPPINGS IN G-METRIC SPACES
VALERIU POPA
In this paper we improve, extend and generalize the main results from V. Popa and G. Puiu, On the common fixed points of several mappings, Stud. Cerc. Mat., 26 (1974) [17], in G - metric spaces for mappings satisfying implicit relations.
μ - SCALE INVARIANT LINEAR RELATIONS IN HILBERT SPACES
ADRIAN SANDOVICI
The concept of μ-scale invariant operator with respect to an unitary transformation in a separable Hilbert space is extended to the case of linear relations (multi-valued linear operators). It is shown that if S is a nonnegative linear relation which is μ -scale invariant for some μ>0, then its adjoint S* and its extreme selfadjoint extensions SF and SN are also μ scale invariant.
OPTIMIZATION PROBLEMS ON QUASI-THRESHOLD GRAPHS
MIHAI TALMACIU
In this paper we characterize quasi-threshold graphs using the weakly decomposition and we determine density and stability number for quasi-threshold graphs.
ABOUT THE AREA OF TRIANGLE DETERMINED BY CEVIANS OF RANK (k,l,m)
NICUŞOR MINCULETE(1), CĂTĂLIN BARBU(2)
In this article we give a characterization of the areas of pedal triangles of some important points from the triangle chosen from C. Kimberling's Encyclopedia of triangle centers. A series of these points being points of concurrence of cevians of rank (k,l,m), of the triangle. Also, we present several equalities regarding these points.