I used to be a fan of DSP, so I had those ideas in mind today at 3AM or something.
Let's suppose Y is in the interval [-1;+1].
EJ : y=INT(SIN(x)) - square pattern ; balancing between +1 and -1.
IP : y=SIN(x) - sine pattern
EP : y=RND - random pattern or white noise.
IJ : y=0 - constant pattern
You see how EJ and IP are dynamic and how EP and IJ are static...