The Children's Library.Sophy H. Powell

George H . McCracken , Jr and Keith R . Powell

Study objective. To develop guidelines for the care of infants and children from birth to 36 months of age with fever without source. Participants and setting. An expert panel of senior academic faculty with expertise in pediatrics and infectious diseases or emergency medicine. Design and intervention. A comprehensive literature search was used to identify all publications pertinent to the mana...

Edwin Powell Hubble

Global convergence and the Powell singular function

The Powell singular function was introduced 1962 by M.J.D. Powell as an unconstrained optimization problem. The function is also used as nonlinear least squares problem and system of nonlinear equations. The function is a classic test function included in collections of test problems in optimization as well as an example problem in text books. In the global optimization literature the function ...

On the stability of Powell–Sabin Wavelets

Recently we developed multiscale spaces of C piecewise quadratic polynomials relative to arbitrary polygonal domains Ω ⊂ R. These multiscale bases are weakly stable with respect to the L2 norm. In this paper we show that these bases form strongly stable Riesz bases for the Sobolev spaces Hs(Ω) with s ∈ (2, 5 2 ).

A multivariate Powell-Sabin interpolant

We consider the problem of constructing a C1 piecewise quadratic interpolant, Q, to positional and gradient data defined at the vertices of a tessellation of n-simplices in IR. The key to the interpolation scheme is to appropriately subdivide each simplex to ensure that certain necessary geometric constraints are satisfied by the subdivision points. We establish these constraints using the Bern...