Multiple Allocation Hub Location Model with Fixed Arc Costs

This article formulates a model to analyze the role of fixed costs in the design of optimal transportation hub networks. The primary purpose of this article is to better model costs in hub networks, an issue that has attracted considerable attention. This article allows particular versions of hub networks to emerge from the cost structure, rather than by imposing a rigid predefined connectivity protocol. The article integrates modeling approaches from an environmental hub location model with the three‐index formulation of Ernst and Krishnamoorthy to produce a hub location model with fixed and variable costs for all arcs. Our goal is to demonstrate how the inclusion of a richer cost model in transportation hub location can generate a wide range of different network types, depending on the relative magnitudes of the cost elements. While the existence of special case network solutions is well known and has been exploited in optimization, the current research provides added insight to the cost of flow in a more, or less, connected hub network. Eight fundamental prototype networks are derived as special cases, and some additional unanticipated network types also emerge. The results are illustrated with a standard CAB25 data set.     

Evaluating the Risk of Plant Closure in the Automotive Industry in Spain

This study looks at the reorganization of production in the context of a multi-plant firm in the automotive industry. Changes in such firms may result in the closure of some plants and/or the opening of others. The article provides a method for assessing the risk of plant closure, and then applies that method to a specific case: the automotive plants located in the Spanish region of Navarre. This entails acknowledging the factors that increase what has come to be known as the “degree of vulnerability” of the plant, including sunk costs and relative productivity levels. This paper can also be understood as a source of information for designing developmental after-care programmes for foreign direct investors in the periphery of the European Union.     

Entropy vs. human ontogeny: the Shannon information measure; a reliable general indicator of human health?

ABSTRACT

A measure of health based on exact sciences is not considered by social sciences to evaluate human development. We propose the H measure of information of Shannon ([1948]. “A Mathematical Theory of Communication.” The Bell Systems Technical Journal 27 (3): 379–423, 623–656), renamed as H _cto , as a general indicator of human health which can be subsequently aggregated at any statistical level. Several advantages of H _cto are explained: (i) connections with thermodynamics and information theory; (ii) combination of physical and statistical elements; (iii) measurements of entropy and/or information depending on the reference point, and (iv) a collection of examples based on the scientific literature that supports the application of H _cto . Simplified graphical models of the ontogeny of health condition are also shown. The empirical feasibility of using H _cto is also analysed, by concluding that it could be a tangible reality in the near future.     

US protection of underwater cultural heritage beyond the territorial sea: problems and prospects

Current US treatment of underwater cultural heritage beyond the territorial sea is analysed in light of Law of the Sea principles and the UNESCO Draft Convention on the Protection of the Underwater Cultural Heritage.