Dear Aleksey Sundeyev,
I don't know the founder of the so called "Israeli" Martial art - "AIKI", and I am practicing and teaching Aikido.
The name "AIKI" is not a hebrew word. "AIKI" is supposed to be the abbreviation of the words : "Israeli Fighting System"
Or in Hebrew: "אמנות קרב ישראלית" - "Amanut Krav Israelit" but then it was supposed to be AKI and not AIKI. I think it is strange.
I heard that Mr. Ami Niv also learned Aikido so I suppose that he chose the name "AIKI" just because the name "Aikido" is famous enough to help his own method be popular...
There is another very interesting and effective Israeli fighting system called "Krav Maga". The meaning of the name in Hebrew is "fight" or "combat".