Clarke Regression

[shipinteraction]

Can anybody on here explain the following coefficients or point me in a direction where they are explained?

Yv'
Yr'
Nv'
Nr'

These four all have dots over the second letter however I am unsure how to do this on here.

Yv'
Yr'
Nv'
Nr'

Thank you in advance.

 

[NavalSArtichoke]

These are some of the so-called 'directional derivatives' which are used to analyze ship maneuvering characteristics. The directional stability of a ship design is one of the areas which must be assessed by model tests or trials of full-size vessels.

Some of the theory of ship maneuvering is explained in Principles of Naval Architecture, Vol. III (1988), which also presents a list of these quantities and their definitions.