President of Four Sigma Corporation, which is engaged in the development and use of algorithmic trading methods for financial markets. He served as President and Chief Executive Officer of The Analytic Sciences Corporation (TASC), which he co-founded in 1966. He held a patent in the area of medical instrumentation and was the editor and coauthor of Applied Optimal Estimation (21st edition, 2009). He served on the Board of Directors of the Massachusetts Port Authority and the Massachusetts Board of Regents of Higher Education. He was a Life Member Emeritus of the MIT Corporation, member of the visiting committees for several departments at MIT, and member of the Lincoln Laboratory Advisory Board. He was a Distinguished Trustee of the Dana Farber Cancer Institute. He was a Fellow of the Institute of Electrical & Electronics Engineers (IEEE), a Fellow of the American Institute of Aeronautics & Astronautics (AIAA), and a Member of the National Academy of Engineering. He was elected a Fellow of the American Academy of Arts and Sciences in 2000 and served as a member of the Academy's Trust and Chair of the Investment Committee.