For seventy years ecologists have debated to what extent competition affects the composition of ecological communities. At one extreme, species have been proposed to assemble independently of each other, while at the other extreme, competition and other interspecific interactions have been...

A Bayes net has qualitative and quantitative aspects: The qualitative aspect is its graphical structure that corresponds to correlations among the variables in the Bayes net. The quantitative aspects are the net parameters. This paper develops a hybrid criterion for learning Bayes net structures...

As disease spreads through a population, scientists want to know who gets sick, how bestto prevent a large outbreak, and if an epidemic may occur. For many years, mathematicians usedmodels to approximate answers to these questions; however, these older models used simplifyingassumptions about...

Commodity and energy prices have exhibited an unprecedented increase between October 2006 and July 2008, only to fall sharply during the last months of 2008. Many explanations have been offered to this phenomenon, including steadily increasing demand from China and India, large mandated...

Nitrate pollution from agriculture is an important environmental problem, caused bythe excessive use of inorganic fertilizers. The internalization of this externality, via a tax onmineral nitrogen, could lead to a second best solution, reducing nitrate emissions. Severalauthors suggest that a...

A water-crop simulation/mathematical programming model of irrigation water demand in northeastern Colorado is formulated to develop an original concept of derived demand for consumptive use of water. Conventional demand functions for water deliveries are also developed, and the effect of...

Recently, Branzei, Dimitrov, and Tijs (2003) introduced cooperative interval-valued games. Among other insights, the notion of an interval core has been coined and proposed as a solution concept for interval-valued games. In this paper we will present a general mathematical programming algorithm...

We analyze the current state and future requirements of an agricultural income stabilization mechanism in a transition country – namely, the crop insurance system in Kazakhstan. Three objectives will be pursued: First, factors influencing the development of the crop insurance market will be...

A mathematical programming model is developed and associated to a spatial pattern index (Ripley L function) to analyse the optimal reserve design and implementation for the Little Bustard conservation in Plaine de Niort. The model structure corresponds to three spatial levels, fields, farm and...

The biological nature of agricultural production processes induce a higher degree ofuncertainty surrounding the economic performance of farm enterprises. This has contributedto the development and acceptance of forms of public intervention aimed at reducing incomevariability that have no...