In many real systems in which a state variable should be controlled for being in appropriate range, the length of control (review) intervals is taken to be constant. In such systems, when the cost of reviews and out-of-range values of the state variable are considerable, this method may not be optimal. In this paper we let the length of review intervals to be variable during each operating cycl...

We consider inventory systems with several distinct items. Demands occur at constant, item specific rates. The items are interdependent because of jointly incurred fixed procurement costs: The joint cost structure reflects general economies of scale, merely assuming a monotonicity and concavity (submodularity) property. Under a power-of-two policy each item is replenished with constant reorder ...

Inductance profile has an important bearing on the performance of a Switched Reluctance Motor (SRM) This paper presents the results of a frequency respolse method to estimate the inductance profde of SRMs. Stator winding is energized by a variable voltage variable Frequency supply. An approximate equivalent circuit incorporating stator resistance, winding inductance and loss component has been ...

We consider the multiplexing of several variable bit rate (VBR) connections over one variable bit rate connection where the multiplexing uses a multiplexing bu er of size B. The VBR trunk is itself a connection and has a multidimensional connection descriptor, reecting peak and sustainable rates. Given a cost function for the VBR trunk and a connection admission control (CAC) method for the inp...

In the tree reconciliation approach for species tree inference, a tree that has the minimum reconciliation score for given gene trees is taken as an estimate of the species tree. The scoring models used in existing tree reconciliation methods include the duplication, mutation, and deep coalescence costs. Since existing inference methods all are heuristic, their performances are often evaluated ...

In “Theory and Application of the Equivalent System Mass Metric,” Levri, Vaccari, and Drysdale computed the Equivalent System Mass (ESM) of crew time. ESM is a cost-type metric based on allocated mass that is often used in life support systems. The previous paper suggested that the cost per hour of crew time should be equal to the ESM of the life support system, divided by the number of availab...