The Advanced Communications Technology Satellite (ACTS) propagation experiment has yielded five years measurements of rain rates and attenuation at 20.185 GHz and 27.505 GHz in seven diverse climate regions throughout North America. Figure 1 shows the former locations of ACTS propagation terminals. In the pursuit of rain attenuation models, rain has generally been classified as stratiform, conv...

Models are the venue for much of the work of the economics profession. We use them to express, compare and evaluate alternative ways of addressing important questions. Applied econometricians are called upon to engage in these exercises using data and, often, formal methods whose properties are understood in decision-making contexts. This is true of work in other sciences as well. There is an e...

An important question in computational biology is how genes are regulated and interact through gene networks. Some methods for the identification of gene networks from temporal data were proposed. An important open problem regards how to validate such resulting networks. This work presents an approach to validate such algorithms, considering three main aspects: (1) AGN model generation and simu...

Like any piece of software, model transformations must be validated to ensure their usefulness for the intended application. Properties to be validated include syntactic correctness as well as general requirements such as termination and confluence (i.e., the existence of a unique result of the transformation for every valid input). This paper introduces the idea of systematic validation and th...

How can economic policies lead us to greater wealth, welfare and happiness? There is no bigger question in economics. The answer lies in correct economic theories that capture the causality linking policies to outcomes. Economic theories are a dime a dozen – we have more theories than we have human beings. The key need to answer any economic question lies in our ability to validate theories. Do...

This paper explores a new approach to validating software implementations that have been produced from formally-verified algorithms. Although visual inspection gives some confidence that the implementations faithfully reflect the formal models, it does not provide complete assurance that the software is correct. The proposed approach, which is based on animation of formal specifications, compar...

Classification trees (J48) were induced to predict the habitat requirements of tench (Tinca tinca). 306 datasets were used for the given fish during 8 years in the river basins in Flanders (Belgium). The input variables consisted of the structural-habitat (width, depth, gradient slope and distance from the source) and physic chemical (pH, dissolved oxygen, water temperature and electric conduct...

In most cases of QSAR modelling the final model used to make predictions, is not known a priori but has to be selected in a data driven fashion (e.g. selection of principal components, variable selection, selection of the best mathematical modelling technique). Reliable estimation of externally validated prediction errors under this model uncertainty is still a challenge in chemoinformatics. To...

Use of disease simulation models has led to scrutiny of model methods and demand for evidence that models credibly simulate health outcomes. We sought to describe recent obstructive lung disease simulation models and their validation. Medline and EMBASE were used to identify obstructive lung disease simulation models published from January 2000 to June 2006. Publications were reviewed to assess...