ロボット系の行列、信用のVaR,並列コンピュ−ティング

最近ロボットの動きを学んでいます。行列を使うことで驚きました。I did not understand why a matrix was needed to express "rotations", or even what a rotation is used for. It seems that the coordinates of a robotic component are expressed as "position" and "orientation.
金融界に信用に関わる財産の値を計算するためクレジットＶａＲと言う工夫を使うそうです。There seem to be multiple approaches to estimating the value of a portfolio of credit instruments (bonds, CDS's) in the future. A probability distribution for such a value is obtained, and the value in the left tail representing the x% cumulative distribution function value is the x% VaR, it seems.
並列コンピューティングはＩＣの構成と関係があるそうです。I am not sure why multithreaded computing is becoming more prominent than instruction level parallelism. ILP seems to involve intelligent scheduling of instructions, which is apparently difficult when under power constraints.