Using the notions of the numerical range, Schur complement and unitary equivalence, an eigenvalue inequality is obtained for a general complex matrix, giving rise to a region in the complex plane that contains its spectrum. This region is determined by a curve, generalizing and improving classical eigenvalue bounds obtained by the Hermitian and skew-Hermitian parts, as well as the numerical ran...

normal range of joint motion is an important factor in joint examination in clinical practice which is related to factors such as age, sex and geographic region. there is no data in the literature on the range of joint motions in healthy iranian adults. we studied joint motions in 100 healthy volunteer subjects, 49 men and 51 women, from 19 and 58 years of age. the joint mobility was examined i...

We analyze the numerical range of high-dimensional random matrices, obtaining limit results and corresponding quantitative estimates in the non-limit case. For a large class of random matrices their numerical range is shown to converge to a disc. In particular, numerical range of complex Ginibre matrix almost surely converges to the disk of radius √ 2. Since the spectrum of non-hermitian random...

This paper studies the problem of Non-symmetric Joint Diagonalization (NsJD) of matrices, namely, jointly diagonalizing a set of complex matrices by one matrix multiplication from the left and one multiplication with possibly another matrix from the right. In order to avoid ambiguities in the solutions, these two matrices are restricted to lie in the complex oblique manifold. We derive a necess...

Although segmental tunnel linings are often used for seismic areas, the influence of segment joints on the segmental lining behavior under seismic loading has not been thoroughly considered in the literature. This paper presents the results of a numerical study investigating the effects of the rotational, axial, and radial joint stiffness of the longitudinal joints on the structural force...

The welding of materials by applying Friction Stir Welding technique is a new solid-state joining technique. The main advantage of this method compared to the traditional joining process is that it minimizes problem-related to metal resolidification as the method incorporates no melting phase. In this experimental work, the effect of friction stir welding (FSW) technique on the microstructu...

In this paper, the behavior of the pseudopolynomial numerical hull of a square complex matrix with respect to structured perturbations and its radius is investigated.

Let J be an involutive Hermitian matrix with signature (t, n− t), 0 ≤ t ≤ n, that is, with t positive and n− t negative eigenvalues. The Krein space numerical range of a complex matrix A of size n is the collection of complex numbers of the form ξ ∗JAξ ξ∗Jξ , with ξ ∈ Cn and ξ∗Jξ = 0. In this note, a class of tridiagonal matrices with hyperbolical numerical range is investigated. A Matlab progr...

In this study, the static stability of the grasp of a single planar object is analyzed using the potential energy method. Inprevious papers, we considered cases in which individual fingers were replaced by a multidimensional translational spring model, inwhich each finger is constructed with prismatic joints. Human hands and the most developed mechanical hands are constructed withre...