The Whirling Blade and the Steaming Cauldron

All rights reserved iii Acknowledgements The moral is, it hardly need be shown, All those who try to go it sole alone, Too proud to be beholden for relief, Are absolutely sure to come to grief. |Robert Frost With high spirits I undertook to thank the many people who have helped me during my graduate tenure at Caltech. I have had the opportunity and pleasure of meeting many very talented people during this period, but unfortunately I am unable to thank them all. I hope those not mentioned here will not take umbrage | be sure that I have not forgotten. John Doyle was always quick to point out the \big picture" and helped me not to lose sight of the forest for the trees. His profound understanding of control theory coupled with his research advice has been a constant and reassuring source of support throughout. John is an interesting and unique advisor. A good deal of my control education was due to Andy Packard. He's always been willing to explain things to me in as much detail as I required. These discussions often occurred over midnight hot dogs with hot peppers when he was here at Caltech. Much of the work in this dissertation was possible because he spent the time to make the theory clear to me. I especially appreciate his eeort to be on my committee. Richard Murray kept me on the right track with his constant encouragement. His keen perception and enthusiasm have been an invaluable asset. While this small encomium is wholly inadequate to express my gratitude, I trust he's aware of it. I'm beholden to Drs. Pietro Perona and Robert McEliece for serving on my dissertation committee. I thank them both very much. Special thanks are due to my fellow students at Caltech. Matt Newlin has been an unwavering beacon of insight and enlightenment. Carolyn Beck worked very hard with me and our collaboration has been a true pleasure. John Morris and I have spent hours discussing control and helping one another throughout our graduate careers. Both Carolyn and John's thoughtful criticisms on this manuscript aided me greatly. Mike Kantner has always been eager to help me with the ducted fan, both now and when I was rst learning to use it. It pleases me more than I can say to count these people as friends as well as colleagues. iv The control group …