BACKGROUND Postdural puncture headache (PDPH), mainly resulting from the loss of cerebral spinal fluid (CSF), is a well-known iatrogenic complication of spinal anesthesia and diagnostic lumbar puncture. Spinal needles have been modified to minimize complications. Modifiable risk factors of PDPH mainly included needle size and needle shape. However, whether the incidence of PDPH is significantly...

Multigroup confirmatory factor analysis was applied to the responses of 4,909 employees of a multinational organization with locations in 50 countries to examine the measurement equivalence of otherwise identical Web-based and paper-and-pencil versions of 20 items comprising the transformational leadership component of Bass and Avolio’s Multifactor Leadership Questionnaire. The results supporte...

The precise relationship of functional writing and pencil grasp has not been determined. Occupational therapists and educators have long recommended the mature dynamic tripod grasp. This grasp provides the most control of the pencil. Variations of this grasp (lateral tripod, dynamic quadrupod, adapted tripod) are common in children with legible handwriting. A grasp with an open web space betwee...

abstract The theory of eigenvalues and eigenvectors of rectangular matrix pencils is complicated by the fact that arbitrarily small perturbations of the pencil can cause them disappear. However, there are applications in which the properties of the pencil ensure the existence of eigen-values and eigenvectors. In this paper it is shown how to develop a perturbation theory for such pencils. ABSTR...

The aim of the present study was to explore the ability of first-year mathematics major students to use a mathematical theorem to solve a problem through a paper-pencil and an electronic-based dynamic assessment. In this study, a convenient and purposeful sampling method was used. Thirty-five students from a public university in voluntarily participated in this study. Data gathering and analysi...

in this paper, we obtain a suitable mathematical model for the seismic response of dams. by using the shear beam model (sb model), we give a mathematical formulation that it is a partial differential equation and transform it to the sturm-liouville equation.

This paper proposes an extension to the existing automatic pencil drawing generation technique based on Line Integral Convolution (LIC). The original LIC pencil filter utilizes image segmentation and texture direction detection techniques for defining outlines and stroke directions, and the quality of a resulting image depends largely on the result of the white noises and the texture directions...

The rational Krylov sequence (RKS) method is a generalization of Arnoldi's method. It constructs an orthogonal reduction of a matrix pencil into an upper Hessenberg pencil. The RKS method is useful when the matrix pencil may be eeciently factored. This article considers approximately solving the resulting linear systems with iterative methods. We show that a Cayley transformation leads to a mor...

This paper presents a new statistical approach to the blind estimation of linear multiple-input multiple-output (MIMO) channels with finite impulse response. A matrix pencil is constructed from a set of fourth-order cumulant matrices of the channel output signals. The MIMO channel impulse responses can then be efficiently estimated from the generalized eigendecomposition of this cumulant matrix...