Generalizations of the Optimal Final Inventory Model
The purpose of this note is to generalize the optimal final inventory model presented previously [Hadley, G., T. M. Whitin. 1961. An optimal final inventory model. Management Sci. 7(2) 179-183]. Two generalizations are made. First, the mean demand is allowed to vary with time so that dynamic situations may be studied. Secondly, the date of obsolescence is no longer required to be fixed but is instead allowed to be described by a probability distribution.
m-scheduling-period inventory model for deteriorating items with instantaneous demand
Abstract A probabilistic inventory model is developed for deteriorating items for a system that operates exactly for m ( m ⩾2) scheduling periods. Deterioration is assumed to be a constant fraction of the on hand inventory; and demand x n in n th period is assumed to be instantaneous immediately after the n th decision regarding the order-level S n has been made at the beginning of the n th period ( n = 1,2,…, m ) the x n being mutually independent. An example is given to illustrate the model.
Efficacy for Dealing With Terrorism Precautionary Behavior: Laying the Groundwork for Communication Effectiveness
In order to formulate effective communication and intervention strategies to respond to the widespread lack of preparedness for public health crises resulting from natural and human-made disasters, researchers have developed models describing the interrelationships between factors associated with emergency preparedness decisions. Empirical research has generally assumed that two key elements of most health behavior theories—self-efficacy and response efficacy—additively influence the decision to prepare, despite compelling theoretical rationale for an interactive relationship. The few studies that have investigated interactions in preparedness outcomes have not tested the Social Cognitive Theory prediction that non-zero levels of both efficacy types are required before individuals will engage in any preparedness behavior. Based on the responses of 3,101 participants in the National Survey of Disaster Experiences and Preparedness, this study tested additive, interactive, and conditional main effect hypotheses about the influence of self-efficacy and response efficacy for dealing with terrorism on preparedness due to terrorism six years after the September 11, 2001, terrorist attacks. A significant self-efficacy × response efficacy interaction effect on preparedness was found, in addition to a significant response efficacy effect when perceived self-efficacy was zero, contrary to the expectation from Social Cognitive Theory. These results offer insights into the cognitive processes underlying individuals’ decisions to prepare for disasters such as terrorist attacks, and highlight the importance of considering more complex theory-based cognitive interaction models in designing effective communication strategies to facilitate individual emergency preparedness.