Andrew C. Singer.Also issued as Thesis (Ph. D.)--Massachusetts Institute of Technology. Dept. of Electrical Engineering and Computer Science, 1996.Includes bibliographical references (p. 137-142).Supported in part by the Defense Advanced Research Projects Agency. N00014-89-J-1489 Supported in part by Lockheed Martin Sanders, and in part by the U.S. Navy Office of the Chief of Naval Research. N00014-93-1-0686 Supported in part by the U.S. Air Force Office of Scientific Research. AFSOR-91-0034