In the context of controlling the attitude of a rigid body, this communique uses recent results on representations of torques (moments) to establish cost functions. The resulting cost functions are both properly invariant under whatever choice of Euler angles is used to parameterize the rotation of the rigid body and have transparent physical interpretations. The function is related to existing...

In the new deregulated electric power market, energy transactions are generally processed in terms of hourly energy delivery. Failing to fulfill energy delivery obligation may result in penaltalt to energy tiesprodp. This paper studies the relationship between generation level schedule, energy delivery schedule and physical ramp-rate of a generating unit. It is shown that although ramp-rate con...

Antiviral agents have been hailed to hold considerable promise for the treatment and prevention of emerging viral diseases like H5N1 avian influenza and SARS. However, antiviral drugs are not completely harmless, and the conditions under which individuals are willing to participate in a large-scale antiviral drug treatment program are as yet unknown. We provide population dynamical and game the...

We consider a Markovian l-unit system which is subject to shocks causing it to deteriorate in each of its stochastically dependent components. The net reward produced by the system is assumed to be an l-dimensional function of the amounts of deterioration of the components. After every shock the controller has the option to replace the system by a new one. The objective is to maximize the long-...

In this research note, we investigate segmentation opportunities for social planners such as government agencies, nonprofits, and public organizations. These opportunities arise when the potential products are vertically (quality) differentiated and the consumers are heterogeneous in their preferences toward quality. In these cases, whether to offer quality differentiated products and what qual...