The main objective of this paper was to identify technical and sanitaryrequirements that could be qualified as export barriers for the Brazilian papaya and to quantify their effects on the volume exported to the United States of America. Themethodology consisted of both qualitative and...

We review the past 25 years of time series research that has been published in journals managed by the International Institute of Forecasters (Journal of Forecasting 1982-1985; International Journal of Forecasting 1985-2005). During this period, over one third of all papers published in these...

We investigate autoregressive approximations of multiple frequency I(1) processes. The underlying data generating process is assumed to allow for an infinite order autoregressive representation where the coefficients of the Wold representation of the suitably filtered process satisfy mild...

In order to control a horizontal axis wind turbine (HAWT) in an optimal manner, one needs accurate measurements of the oncoming wind conditions. The method currently used by large wind power manufacturers is to measure wind speed and direction on top of the nacelle behind the rotor. In order for...