Let M<=R be a minimal surface. A domain Z><= M is an open connected set with compact closure D and such that its boundary dD is a finite union of piecewise smooth curves. We say that D is stable if D is a minimum for the area function of the induced metric, for all variations of D which keep dD fixed. In this note we announce the following estimate of the "size" of a stable minimal surface. We ...

To compare the velocity characteristics of wheelchair propulsion with and without the use of a tennis racquet, eight male wheelchair tennis players performed a series of 20m sprints from a stationary start. The maximum velocities reached on average 4.39 ± 0.74 m/s; however, they were reduced by 0.18 ± 0.06 m/s during the racquet condition. Furthermore, when wheeling under the racquet condition,...

Based on the cranking model and the random phase approximation, we point out that the wobbling excitation on top of the s band in Os is stable against angular momentum tilting. This is consistent with the general trend that the wobbling excitations in γ < 0 rotating nuclei are more stable than those in γ > 0 ones found in our previous studies. In higher N isotopes known to be γ soft, however, a...

The lack of stability in some matching problems suggests that alternative solution concepts to the core might be a step towards furthering our understanding of matching market performance. We propose absorbing sets as a solution for the class of roommate problems with strict preferences. This solution, which always exists, either gives the matchings in the core or predicts other matchings when ...

We consider a method for constructing uniformly stable spline approximations for scalar delay equations.

It is demonstrated that the method of steps for linear delay-differential equation together with the inverse Laplace transform can be used to find a converging sequence of polynomial approximants to the transcendental function determining stability of the delay equation. Numerical stability charts are shown to illustrate convergence. This approach can serve as a basis for an efficient numerical...

This paper introduces a new class of methods, which we call Möbius schemes, for the numerical solution of matrix Riccati differential equations. The approach is based on viewing the Riccati equation in its natural geometric setting, as a flow on the Grassmanian of m-dimensional subspaces of an (n + m)-dimensional vector space. Since the Grassmanians are compact differentiable manifolds, and the...

The application of convolution potential voh.ammetry to questions of metal complexation is described. Theoretical relations are derived to show that the stability constants may be directly related to the shift in the peak potential of the semiderivative wave, provided the complexes are labile. Equations are also given for inert and quasilabile complexes. Stability constants for the PbCI, and Cd...

Contraction theory provides an elegant way of analyzing the behaviors of systems subject to external inputs. Under sometimes easy to check hypotheses, systems can be shown to have the incremental stability property that all trajectories converge to a unique solution. This property is especially interesting when forcing functions are periodic (a globally attracting limit cycle results), as well ...