A feature of new economic geography model is their mathematical intractability. This intractability results from the fact that the functional relationship between the indirect utility differential and the state variable cannot be found explicitly. We illustrate three methods that can be utilized...

Models are presented for the optimal location of hubs in airline networks, that take into consideration the congestion effects. Hubs, which are the most congested airports, are modeled as M/D/c queuing systems, that is, Poisson arrivals, deterministic service time, and {\em c} servers. A formula...

In this paper we extend the smoothing technique [7], [9] onto the problems of Semidefinite Optimization. For that, we develop a simple framework for estimating a Lipschitz constant for the gradient of some symmetric functions of eigenvalues of symmetric matrices. Using this technique, we can...

Exporting countries are concerned that sanitary standards might shield domestic industry from foreign competition. This study analyzes economic effects of changes in Western Hemisphere sanitary requirements on broiler trade in the Americas. A mathematical programming model detects that if Brazil...

The optimal location of services is one of the most important factors that affects service quality in terms of consumer access. On the other hand, services in general need to have a minimum catchment area so as to be efficient. In this paper a model is presented that locates the maximum number...

Research on judgment and decision making presents a confusing picture of human abilities. For example, much research has emphasized the dysfunctional aspects of judgmental heuristics, and yet, other findings suggest that these can be highly effective. A further line of research has modeled...