There are probably no good ways to do it, only manually.
AFAIK, JPA doesn't offer standardized support for calculated attributes. With Hibernate, one would use a Formula but EclipseLink doesn't have a direct equivalent. James Sutherland made some suggestions in Re: Virtual columns (@Formula of Hibernate) though.
I cant really gove you an answer,but what I can give you is a way to a solution, that is you have to find the anglde that you relate to or peaks your interest. A good paper is one that people get drawn into because it reaches them ln some way.As for me WW11 to me, I think of the holocaust and the effect it had on the survivors, their families and those who stood by and did nothing until it was too late.