All issues
 27.05.2017
Creative Mathematics
and Informatics

 Print Edition: ISSN 1584 - 286X Online Edition: ISSN 1843 - 441X Creative Math. and Inf. is a category B+ journal in the CNCSIS classification Indexed by: Mathematical Reviews Zentralblatt MATH Current rejection rate: 37.5 % RSS
Contents (PDF)
Vol. 23 (2014), No. 1, 15 June 2014
 On the $1$-homogeneous non-linear connections Author: Esmaeil Azizpour / Seddighe Darsaraei / Seyed Sajjad Pourmortazavi Abstract: In this paper, we show that for every semispray $S$ on a vector bundle $(R\times TM , \pi , R\times M),$ there are several sequences of semisprays and correspondingly several nonlinear connections associated to it. It is important to derive conditions on $S,$ which guarantee that a sequence of nonlinear connections associated to $S$ is constant. We show that the homogeneity condition for $S$ yields the result. PDF | No. of downloads: 189 Bivariate uniform approximation via bivariate Lagrange interpolation polynomials Author: Dan Bărbosu / Ovidiu T. Pop Abstract: In the present note, we extend some univariate uniform approximation results by means of Lagrange interpolating polynomials [Ivan, M., Elements of Interpolation Theory, Mediamira Science Publisher, Cluj-Napoca (2004)] to the bivariate case. It is well known that generally, in the univariate case, the sequence of Lagrange interpolation polynomials does't converges to the approximated function. This fact was first observed by G. Faber (see [9]), which constructed an example when the sequence of Lagrange interpolation polynomials diverges. The result of G. Faber was more generalized by I. Muntean (see [12]). M. Ivan established first sufficient conditions for the uniform convergence of the sequence of Lagrange interpolation polynomials associated to a univariate real valued function. First, we represent the remainder term of bivariate Lagrange interpolation formula in terms of bivariate divided difference. Using this representation we establish sufficient conditions for the uniform convergence of the sequence of bivariate Lagrange interpolation polynomials to the approximated function. PDF | No. of downloads: 205 A man who had known his star in the sky. A homage to Professor Eugen Grebenikov (1932-2013) Author: Vasile Berinde Abstract: The main aim of this note is to present some data about the education, professional activity and scientific publications of Professor Eugen Grebenikov (1932-2013), a distinguished mathematician born in 1932 at Slobozia Mare, Ismail county, Romania (now in Republic of Moldova) who was educated and had worked for most of his life time in Moscow. Some author' s personal recollections are also included. PDF | No. of downloads: 152 A mathematical model for the study of contamination of honey with lead and cadmium in Baia Mare area Author: Zoița Mărioara Berinde / Angela Mariana Michnea / Anamaria Gavra / Gheorghe Ardelean Abstract: Eleven samples of honey collected from different locations spread in the Baia Mare area and situated at various distances from the pollution source, the company Romplumb S.A. (while it has been in operation and after its closure in January 2012) were studied to determine the presence of the Pb and Cd by electrothermal atomic absorption spectrometry. It has been found that the concentration of lead and cadmium is generally correlated with the degree of pollution of the environment with these heavy metals, as well as with the distances from the pollution source and the directions of circulation of the contaminated air. In order to characterize the contamination of honey we introduced the index of contamination (IC) that shows a medium contamination for Pb and weak contamination for Cd in the period the pollution source was active and a weak contamination for Pb and no contamination for Cd after the closure of the metallurgical plant. We obtained a mathematical model representing the concentration of Pb in honey with respect to the geographical position in case the air was also contaminated with Pb, and showing more clearly the influence of air flows on the contamination of honey. PDF | No. of downloads: 183 About the implementation and some applications of the FIXPOINT software minipackage Author: Andrei Bozântan / Vasile Berinde Abstract: The main aim of this note is to briefly present the implementation, main features and some current and potential applications of the software minipackage FIXPOINT, designed and implemented by the first author and used by the second author in solving some concrete problems. PDF | No. of downloads: 157 Remarks on notions of $\mu^*$-open sets Author: Carlos Carpintero / Ennis Rosas / Margot Salas / Ivan Blanco / Martha Polo Abstract: The purpose of this paper is to show that the construction leading from a generalized topology $\mu$ and a hereditary class of sets $\mathcal{H}$ to another generalized topology $\mu^*$ remains valid, together with a lot of properties, if the generalized topology $\mu$ and the hereditary class $\mathcal{H}$ are replaced by arbitrary classes of subsets. PDF | No. of downloads: 190 Fixed point theorems for multivalued generalized contractions with respect to two topologically equivalent metrics Author: Iulia Coroian Abstract: In this paper, we will present some fixed point results for multivalued almost contractions with respects to two topologically equivalent Hausdorff type metrics. PDF | No. of downloads: 148 Fixed point theorems for almost contractions in generalized metric spaces Author: Luljeta Kikina / Kristaq Kikina / Ilir Vardhami Abstract: Fixed point theorems for almost contractions in generalized metric spaces are proved. The obtained results are extensions and generalizations, from metric space setting to generalized metric space setting, of many well-known fixed point theorems in literature. PDF | No. of downloads: 176 Investigating the effectiveness of advertising on declining social networks Author: Gergely Kocsis / Imre Varga Abstract: In this paper we aim to investigate the question if it's worth it to advertise on declining social networks or not. Our investigations are based on computer simulations using a previously defined and here simplified model of information spreading. To make our results as close to the real life as possible we run simulations both on a real network sample and on several generated networks representing as well classical scale-free-like social topologies as declining social networks. As a result we found how the continuous destruction of the network affects the spreading, changing also the effectiveness of the advertising. PDF | No. of downloads: 159 Integrability of trigonometric series with coefficients from the class ${\bf K}$ Author: Xhevat Z. Krasniqi Abstract: In this paper we deal with a class of sine and cosine trigonometric series. We have imposed some conditions on their coefficients so that their sums will be integrable with the exception of two points. In fact, some estimates of the integrals of the absolute values of their sums, expressed in terms of the coefficients, are obtain extending some results of a paper Telyakovskii, S. A., Localizing the conditions of integrability of trigonometric series, Trudy Mat. Inst. Steklov., 210 (1995), 264--273 (Russian). PDF | No. of downloads: 171 Some inequalities for geometrically-arithmetically $h$-convex functions Author: Muhammad Aslam Noor / Khalida Inayat Noor / Muhammad Uzair Awan Abstract: In this paper, we consider a class of geometrically convex function which is called geometrically-arithmetically $h$-convex function. Some inequalities of Hermite-Hadamard type for geometrically-arithmetically $h$-convex functions are derived. Several special cases are discussed. PDF | No. of downloads: 183 Fixed point theorems for multivalued generalized contractions of rational type in complete metric spaces Author: Anca M. Oprea Abstract: The purpose of this paper is to present some fixed point theorems for multivalued contractions of rational type. We extend the results of I. Cabrera, J. Harjani and K. Sadarangan, A fixed point theorem for contractions of rational type in partially ordered metric spaces, Annali dellâ€™Universita di Ferrara, DOI 10.1007/s11565-013-0176-x, to the case of multivalued operators. PDF | No. of downloads: 155 Stolarsky type means related to an extension of H\"{o}lder-type inequality Author: Ksenija Smoljak Abstract: In this paper linear functionals related to an extension of HÃ¶lder-type inequality are defined and their $n-$exponential convexity is proved. Furthermore, new Stolarsky type means, using families of exponentially convex functions, are defined and their monotonicity property is proved. PDF | No. of downloads: 154 Generalized Pell numbers, balancing numbers and binary quadratic forms Author: Ahmet Tekcan / Merve Tayat Abstract: In this work, we derive some algebraic identities on generalized Pell numbers and their relationship with balancing numbers. Also we deduce some results on binary quadratic forms involving Pell and balancing numbers. PDF | No. of downloads: 169 Properties and inequalities for the $\boldsymbol{h}$- and $\boldsymbol{(h,m)}$-logarithmically convex functions Author: Bo-Yan Xi / Shu-Hong Wang / Feng Qi Abstract: In the paper, the authors introduce definitions of $h$-logarithmically convex functions and $(h,m)$-logarithmically convex functions respectively, discuss some properties of these kinds of functions, and establish some integral inequalities for these kinds of functions. PDF | No. of downloads: 168

Design by PrimeTech