Willem J. Willems

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Two types of eye-controlled aids for two categories of nonvocal patients with paralysis are described: one based on the use of an eye switch by the partially defect eye for the selection of letters and the other based on position recording of the intact eye during its fixation on the desired letter. The eye recording device for both aids was designed to be(More)
  • Z Hu, X Li, D Mills, E M Uller, W Sun, W Willems +2 others
  • 2007
Let p be a prime with p 3 (mod 4), let n be an odd natural number and let d = p n +1 p+1 ? p n ?1 2. Consider the crosscorrelation function C d (t) = P p n ?1 i=1 a i ?a di?t where 6 = 1 is a complex p-th root of unity and (ai) is a maximal linear shift register sequence. In 7] the bound j1 + C d (t)j 2 p 3 n has been computed for p = 3. In this note we(More)
After placement of a reverse shoulder endoprosthesis, range of motion is usually still compromised. To what extent this occurs from limitation in motion of the reverse endoprosthesis is, however, unclear. We measured the motion pattern of 16 patients (18 shoulders) during three active and passive range of motion tasks using a six degree-of-freedom(More)
The suitability of tetrodotoxin (TTX) for studies of the neural control of vascular smooth muscle (VSM) tone in the microcirculation was evaluated by determining 1) whether TTX blockade of neural input to adrenergically innervated VSM is reversible and 2) whether TTX depresses active VSM tone directly. Diameters of rat mesenteric veins and third- and(More)
Based on a large amount of examples, which we have checked so far, we conjecture that |G| p ≤ ϕ ϕ(1) 2 where p is a prime and the sum runs through the set of irreducible Brauer characters in characteristic p of the finite group G. We prove the conjecture simultaneously for p-solvable groups and groups of Lie type in the defining characteristic. In(More)
BACKGROUND Optimal treatment of the diseased long head of the biceps (LHB) tendon during rotator cuff repair remains a topic of debate: tenotomy or tenodesis. A recent meta analysis revealed no difference in strength or functional outcome between treatments. The included studies varied in methodological quality, and only two were randomized controlled(More)
INTRODUCTION The increase of shoulder replacements will lead to a higher revision rate of shoulder arthroplasties. The aim of this study is to evaluate the clinical results of revision surgery performed in our hospital, distinguish the differences in clinical outcome according to revision indication and differences between total shoulder arthroplasty (TSA)(More)
  • H J M Van Grinsven, H F M Ten Berge, T Dalgaard, B Fraters, P Durand, A Hart +10 others
  • 2012
Biogeosciences Discussions This discussion paper is/has been under review for the journal Biogeosciences (BG). Please refer to the corresponding final paper in BG if available. * All authors of this paper are involved in the implementation or evaluation of the Nitrates Directive in their country or at the EU27 level, but views and data in this paper not(More)
Let A and B be stochastic matrices of the same type (n; n). It is natural to consider perturbations A(t) of A of the form A(t) = (1 ? t)A + tB (0 t 1): Now, the following two questions come up immediately. (1) When does lim k!1 A(t) k exist? (2) How does lim k!1 A(t) k behave for small t? As the existence of lim k!1 A(t) k depends only on the eigenvalues of(More)