Approximation properties of generalized Baskakov–Schurer–Szasz–Stancu operators preserving e − 2 a x , a > 0 $e^{-2ax}, a>0$

A characterization of orthogonality preserving operators

‎In this paper‎, ‎we characterize the class of orthogonality preserving operators on an infinite-dimensional Hilbert space $H$ as scalar multiples of unitary operators between $H$ and some closed subspaces of $H$‎. ‎We show that any circle (centered at the origin) is the spectrum of an orthogonality preserving operator‎. ‎Also‎, ‎we prove that every compact normal operator is a strongly orthogo...

An Approximation for Ç ^ e ' ^ f dt , x > 0 ,

A new approximation is given for ¡xe ' t? dt, x > 0, p real, which extends an earlier approximation of Boyd's for p = 0. Introduction. In [2] Boyd gives (1) £0) = 4/[3* + y/x2 + 8] as an approximation for (2) F(x) = [1 IZ(x)] f " Z(t) dt, x>0, J X where (3) ZO)=exp(-x2/2). It can be shown g(x) > F(x), and in fact (4) g(x) F(x) = 2X-1 + 0(x~9), 0 -+ -)• For x > c = (4 t')I\Jtx(ix 2) s .453, gfx)...

A Generalized Fibonacci Sequence and the Diophantine Equations $x^2pm kxy-y^2pm x=0$

In this paper some properties of a generalization of Fibonacci sequence are investigated. Then we solve the Diophantine equations $x^2pmkxy-y^2pm x=0$, where $k$ is positive integer, and describe the structure of solutions.

E D U Cat I O N N E X T / F a L L 2 0 0 8

some properties of fuzzy hilbert spaces and norm of operators

in this thesis, at first we investigate the bounded inverse theorem on fuzzy normed linear spaces and study the set of all compact operators on these spaces. then we introduce the notions of fuzzy boundedness and investigate a new norm operators and the relationship between continuity and boundedness. and, we show that the space of all fuzzy bounded operators is complete. finally, we define...