BACKGROUND Grip size of a tennis racquet has been reported to influence performance, but clear evidence of a correlation has yet to be established. HYPOTHESIS Hitting force during a soft tennis forehand stroke correlates with grip size. STUDY DESIGN Controlled clinical study. METHODS A total of 40 healthy volunteers (20 men and 20 women) with a mean age of 21.9 years were enrolled. Of the...

We consider the problem of hitting sets online. The hypergraph (i.e., rangespace consisting of points and ranges) is known in advance, and the ranges to be stabbed are input one-by-one in an online fashion. The online algorithm must stab each range upon arrival. An online algorithm may add points to the hitting set but may not remove already chosen points. The goal is to use the smallest number...

We consider general quantum random walks in a d-dimensional half-space. We first obtain a path integral formula for general quantum random walks in a d-dimensional space. Our path integral formula is valid for general quantum random walks on Cayley graphs as well. Then the path integral formula is applied to obtain the scaling limit of the exit distribution, the expectation of exit time and the...

2 We study mechanisms of anomalous transport in quenched random media. Broad disorder point distributions and strong disorder correlations cause anomalous transport and can lead to the same anomalous scaling laws for the mean and variance of the particle displacements. The respective mechanisms, however, are fundamentally different. This difference is reflected in the spatial particle densities...

Set Cover is a well-studied problem with application in many fields. A well-known variant of this the Minimum Membership problem: Given set points and objects, objective to cover all while minimizing maximum number objects that contain any one point. dual Hitting stab an object contains. We study both these variants geometric setting various types plane, including axis-parallel line segments, s...

We consider polyhedral versions of Kannan and Lipton's Orbit Problem [14, 13] determining whether a target polyhedron V may be reached from a starting point x under repeated applications of a linear transformation A in an ambient vector space Q. In the context of program veri cation, very similar reachability questions were also considered and left open by Lee and Yannakakis in [15], and by Bra...