Sticking probabilities of fractal aggregates

An attempt was made to experimentally estimate the sticking probabilities of fractal aggregates of fine particles. The experiment was done using MgO fine particles floating in air under normal gravity. The growth in size of the aggregates was monitored by scattered He-Ne laser light. Our preliminary result suggests that the sticking probability decreases with increase in aggregate size. There are, however, still many uncertainties in the method of determining the sticking probabilities. Since this study is still at a developing stage, in this article we provide a general description of the experimental set-up, without giving details of various aspects of the problem

ベイズモデリングによる実世界問題チャレンジ

Open House, ISM in Tachikawa, 2010.7.9統計数理研究所オープンハウス（立川）、H22.7.9ポスター発

BASEBALL SPIN AND PITCHERS’ PERFORMANCE

The motion of the ball thrown by a pitcher is influenced by three forces: gravity, drag force due to air resistance, and lift force which deflects a ball vertically or laterally due to ball spin. The lift force acting on the ball increases with spin rate and movement speed when the spin axis of the ball is orthogonal to the direction of ball movement. Among individual pitchers there were great variations in spin on their fastballs, both in spin rate and in direction of the spin axis. Ball spin rate was positively correlated with increases in distance from the optimal contact point of the swung bat (sweet spot) to the actual point of contact. That is, batters tend to hit under the ball when it has a high spin rate, even for balls of the same velocity. Abnormal or unique ball spin is an important aspect of superior performance for pitchers

今後のHPC環境における統計計算アルゴリズム

平成21年度研究報告会、統計数理研究所(広尾）、H22.3.18-19口頭発