I very much appreciate everyone's input. There have been many excellent suggestions on how to achieve kokyu, such as relaxing completely, closing the armpits, dropping the shoulders, allowing energy to flow from the big toe to the fingertips, and extending the fingers. I am not quite sure what does it mean to close the spine, though, if anyone could clarify that, it would be much appreciated.
I noticed that some questions were raised regarding tensions felt in kokyu, and I would like to address them now. I believe that the tensions felt are not at all intentional and that the muscles must be completely relaxed. I believe the tension comes after movement begins as is demonstrated in the following example: take two beer cans, and tie a string to one end, and then thread the string all the way through out the end of the 2nd can. Now at this point the cans are completely relaxed, but once you pull on the string (this simulates movement either toward or away from nage) the cans pull together creating a "tension" between them. By the way, make sure the beer cans are emptied before trying this....this will help with total relaxation.
While many good examples were cited on achieving kokyu, I think what I'm looking for with this thread is more along the lines of a short explanation, such as kokyu is.....
I'm still puzzled on where the term "breath" fits into all of this. Is it perhaps meant as a spiritual or philosophical reference, and not a literal one as relating to the practical application? I'm afraid that from my experience I can't agree that it means coordinating breathing with techniques, or simply kiai. I am also in disagreement with those who say it is the rotating of the arms forward. This raises the elbows, opens the armpits, and collects power in the deltoids, or upper shoulders.
I read Gozo Shioda's book, but found that he vaguely describes the meaning of kokyu. He goes into detail about center power and focused power, but not about kokyu power. Koichi Tohei does a superb job describing ki, but not kokyu.
If such a term which is so important to the application of the art is not clearly understood by so many, it is no wonder that it takes so long to learn! I don't know of any other art, where such a basic term is left so vague. Can you imagine studying music and not knowing what a "playing a chord" means?
Thank you to those who take the time to write.