In this article, we prove an inner product inequality for Hilbert space operators. This inequality, then, is utilized to present a general numerical radius using convex functions. Applications of the new results include obtaining forms that generalize and extend some well known in literature, with application newly defined generalized radius. We emphasize approach followed article different fro...

We give a brief account of the numerical radius of a linear bounded operator on a Hilbert space and some of its better-known properties. Both finiteand infinitedimensional aspects are discussed, as well as applications to stability theory of finite-difference approximations for hyperbolic initial-value problems. 1. DEFINITION, BOUNDS, AND EVALUATION Let H be a Hilbert space over the complex fie...

Recently, Uhlig [Numer. Algorithms, 52(3):335-353, 2009] proposed open questions about the ratios between the spectral norm, the numerical radius and the spectral radius of a square matrix. In this note, we provide some observations to answer these questions. Keywords—Spectral norm, Numerical radius, Spectral radius, Ratios

In this work, an improvement of Hölder–McCarty inequality is established. Based on that, several refinements the generalized mixed Schwarz are obtained. Consequently, some new numerical radius inequalities proved. New for $$n\times n$$ matrix Hilbert space operators proved as well. Some earlier results were in literature also given. presented refined and it shown to be better than literature.

production and preparation of many parts of the aircraft body including wings with long length, smooth form, and large radius of curvature are amongst the most important challenges in this industry. in this paper, the effective factors in the rubber pad forming method on a pieces contain curvature radius have been investigated by finite element method. the effect of variables such as curvature ...

In the Manning equation the hydraulic radius can be defined as the cross-section dimension of the shape. In pipe flow the bed shear stress is assumed to be uniformly distributed along the wetted perimeter which cannot be true in open channel flow. Hence, three approximation of the true boundary shear-stress distribution are examined and more practical conveyance depth or resistance radius formu...

for a ∈ mn, the schur multiplier of a is defined as s a(x) =a ◦ x for all x ∈ mn and the spectral norm of s a can be stateas ∥s a∥ = supx,0 ∥a ∥x ◦x ∥ ∥. the other norm on s a can be definedas ∥s a∥ω = supx,0 ω(ω s( ax (x ) )) = supx,0 ωω (a (x ◦x ) ), where ω(a) standsfor the numerical radius of a. in this paper, we focus on therelation between the norm of schur multiplier of product of matric...

Two useful measures of the robust stability of the discrete-time dynamical system xk+1 = Axk are the -pseudospectral radius and the numerical radius of A. The -pseudospectral radius of A is the largest of the moduli of the points in the -pseudospectrum of A, while the numerical radius is the largest of the moduli of the points in the field of values. We present globally convergent algorithms fo...

There are several parameters that have significant influence in metal forming process. One of the most important of them is friction coefficient. Friction can change the pattern of metal flow and the force needed for deformation. It is necessary to determine the friction coefficient to study the effect of friction on metal forming process. This study is concerned with numerical and experimental...