1. Mitsubishi Electric Research Labs, Cambridge, Massachusetts 02139;
2. Operations and Information Management, University of Connecticut, Storrs, Connecticut 06260;
3. Tepper School of Business, Carnegie Mellon University, Pittsburgh, Pennsylvania 15213;
4. Freeman College of Management, Bucknell University, Lewisburg, Pennsylvania 17837;
5. Advanced Technology R&D Center, Mitsubishi Electric Corporation, Hyogo 661-8661, Japan