Right Concentration == 正定
right abstraction, the eighth of the Eightfold Path; meditation, focusing the mind without distraction, preparing the mind to attain wisdom.
Three Studies == 三学(戒、定、慧)
or Three Vehicles of Learning
1.Sila, i.e. taking Precepts
2.Dhyana, i.e. concentration and meditation
3.Prajna, i.e. wisdom
It is practiced by the Arhats.
adhitthana == 决定,决意,受持,依处,摄持