ARMA models provide a parsimonious and flexible mechanism for modeling the evolution of a time series. Some useful measures of these models (e.g., the autocorrelation function or the spectral density function) are tedious to compute by hand. This paper uses a computer algebra system, not...

We have recently developed a package in Maple that allows to perform logical computations in any existing or proposed many-valued logic (that can be defined using truth tables). It has applications in logic engineering (e.g. when creating a new logic adapted to some requirements), in theoretical...

The length of the Spanish broad gauge network has decreased in the 1956–2006 period. When looking at different railway maps through this period, it seems that the network is offering fewer and fewer alternatives when a line is cut, that is, the network is becoming less and less flexible. The...

We discuss using computer algebras systems (CAS) in an undergraduate intermediate macroeconomics class. The criteria used in choosing a CAS are considered. One criterion was that students would bear little or no financial. The lessons learned in implementing a CAS – things that worked well and...

The authors have developed a package that can simulate in detail passengers’ traffic within the departures terminal of Málaga airport. This is one of the main Spanish airports, with an average traffic of more than 20,000 passengers/day, and a high ratio of charter flights with European...

A railway interlocking is a device that supervises train operation (signaling and position of switches) authorization and prevents conflicting actions from being authorized. An expert system for route selection in a railway interlocking is presented, that is independent of the station topology....