Despite the fact that soccer is one of the most popular sports in the world, little attention has been paid to this game scientifically which could otherwise provide a broad range of interesting outcomes. Sport equipment has a significant effect on how a game is played. Different features of the soccer ball such as its size, structure, weight and potential incoming pressure also affect the natu...

We give a new proof that every linear fractional map of the unit ball induces a bounded composition operator on the standard scale of Hilbert function spaces on the ball, and obtain norm bounds analogous to the standard one-variable estimates. We also show that Cowen’s one-variable spectral radius formula extends to these operators. The key observation underlying these results is that every lin...

BACKGROUND Weighted-ball throwing programs are commonly used in training baseball pitchers to increase ball velocity. The purpose of this study was to compare kinematics and kinetics among weighted-ball exercises with values from standard pitching (ie, pitching standard 5-oz baseballs from a mound). HYPOTHESIS Ball and arm velocities would be greater with lighter balls and joint kinetics woul...

A ball-polyhedron is the intersection with non-empty interior of finitely many (closed) unit balls in Euclidean 3-space. One can represent the boundary of a ballpolyhedron as the union of vertices, edges, and faces defined in a rather natural way. A ball-polyhedron is called a simple ball-polyhedron if at every vertex exactly three edges meet. Moreover, a ball-polyhedron is called a standard ba...

Magic illusions provide the perceptual and cognitive scientist with a toolbox of experimental manipulations and testable hypotheses about the building blocks of conscious experience. Here we studied several sleight-of-hand manipulations in the performance of the classic "Cups and Balls" magic trick (where balls appear and disappear inside upside-down opaque cups). We examined a version inspired...

Child running and jumping sound are one of the major noise sources in heavy structured apartment building. It was reported that physical characteristics of rubber ball (heavy/soft impact sound) was similar with child's running and jumping. As a standard impact source, rubber ball was standardized in ISO 10140 series and ISO 16283-2. However, evaluation method of rubber ball was not proposed in ...

Recognizing the arbitrary standard FIFA ball is a significant ability for soccer robots to play competition without the constraint of current color-coded environment. This paper describes a novel method to recognize arbitrary FIFA ball based on omni-directional vision system. Firstly the omni-directional vision system and its calibration for distance map are introduced, and the conclusion that ...