The impact of emergency nursing roles in demand management systems is poorly understood. The aim of this study was to evaluate emergency nurses' role in a specific emergency department (ED) demand management system: rapid intervention and treatment zone (RITZ). A descriptive exploratory approach was used. Data were collected from audit of 193 randomly selected patient records and 12 h of clinic...

Preconditioned gradient iterations for very large eigenvalue problems are efficient solvers with growing popularity. However, only for the simplest preconditioned eigensolver, namely the preconditioned gradient iteration (or preconditioned inverse iteration) with fixed step size, sharp non-asymptotic convergence estimates are known. These estimates require a properly scaled preconditioner. In t...

The Rydberg formula along with the Ritz quantum defect ansatz has been a standard theoretical tool used in atomic physics since before advent of mechanics, yet this approach remained limited by its nonrelativistic foundation. Here I present long-distance relativistic effective theory describing hydrogenlike systems arbitrary mass ratios, thereby extending canonical Ritz-like approach. Fitting t...

Let (; x) be an eigenpair of the Hermitian matrix A of order n and let (; u) be a Ritz pair from a subspace K of C 2. Saad has given a simple inequality bounding sin \(x; u) in terms of sin \(x; K). In this note we show that this inequality can be extended to an equally simple inequality for eigenspaces of non-Hermitian matrices. ABSTRACT Let (; x) be an eigenpair of the Hermitian matrix A of o...

This paper discusses a few algorithms for updating the approximate Singular Value Decomposition (SVD) in the context of information retrieval by Latent Semantic Indexing (LSI) methods. A unifying framework is considered which is based on Rayleigh-Ritz projection methods. First, a Rayleigh-Ritz approach for the SVD is discussed and it is then used to interpret the Zha-Simon algorithms [SIAM J. S...

The objective of this paper is to present a comparative study of fitted-mesh finite difference method, Ritz-Galerkin finite element method and B-spline collocation method for a two-parameter singularly perturbed boundary value problems. Due to the small parameters ε and μ, the boundary layers arise. We have taken a piecewise-uniform fittedmesh to resolve the boundary layers and shown that fitte...