控制的目的是使系统在存在不确定性和干扰的情况下仍能按期望的方式运行。

The interplay between theory and observation is what advances astrophysics.

People, even more than things, have to be restored, revived, reclaimed and redeemed;never throw out anyone.

Every artist dips his brush in his own soul, and paints his own nature into his pictures.

The essence of mathematics is not just in solving problems but in asking the right questions.

You don’t have to have it all figured out to move forward. Just take the next step.