Analysis of return patterns of digital hearing aids

This paper examines the return rate for digital hearing aids and reason for the returns.

Analysis of return patterns of digital hearing aids

This paper examines the return rate for digital hearing aids and reason for the returns.

Propuesta de creación de una empresa agroexportadora de stock (Matthiola Incana), para el mercado de flores de verano

La tesis titulada "Propuesta de creación de una empresa agroexportadora de Stock (Matthiola Incana) para el mercado de flores de verano" es un trabajo práctico que busca incorporar todos los elementos necesarios para plantear la creación de una empresa que se dedique a la producción de una flor de verano comercialmente conocida como Stock. En su desarrollo se ha considerado pnmero el análisis del entamo macroeconómico para determinar su posible impacto sobre el desempeño de la compañía. Posteriormente se ha definido la planeación estratégica y estructura que debería tener la empresa, Posteriormente se ha determinado las diferentes etapas del proceso productivo que van desde la preparación del suelo hasta la poscosecha y forma de comercialización de la flor producida. Finalmente, en base a la información recabada, se ha realizado una breve evaluación comercial, evaluación técnica y evaluación financiera que son elementos decisivos para determinar si la puesta en práctica de "Florícola Gardens" es viable en los diferentes aspectos antes señalados.

A note on atmospheric predictability

Using the method of Lorenz (1982), we have estimated the predictability of a recent version of the European Center for Medium-Range Weather Forecasting (ECMWF) model using two different estimates of the initial error corresponding to 6- and 24-hr forecast errors, respectively. For a 6-hr forecast error of the extratropical 500-hPa geopotential height field, a potential increase in forecast skill by more than 3 d is suggested, indicating a further increase in predictability by another 1.5 d compared to the use of a 24-hr forecast error. This is due to a smaller initial error and to an initial error reduction resulting in a smaller averaged growth rate for the whole 7-d forecast. A similar assessment for the tropics using the wind vector fields at 850 and 250 hPa suggests a huge potential improvement with a 7-d forecast providing the same skill as a 1-d forecast now. A contributing factor to the increase in the estimate of predictability is the apparent slow increase of error during the early part of the forecast.

The predictability of extratropical storm tracks and the sensitivity of their prediction to the observing system

A new method for assessing forecast skill and predictability that involves the identification and tracking of extratropical cyclones has been developed and implemented to obtain detailed information about the prediction of cyclones that cannot be obtained from more conventional analysis methodologies. The cyclones were identified and tracked along the forecast trajectories, and statistics were generated to determine the rate at which the position and intensity of the forecasted storms diverge from the analyzed tracks as a function of forecast lead time. The results show a higher level of skill in predicting the position of extratropical cyclones than the intensity. They also show that there is potential to improve the skill in predicting the position by 1 - 1.5 days and the intensity by 2 - 3 days, via improvements to the forecast model. Further analysis shows that forecasted storms move at a slower speed than analyzed storms on average and that there is a larger error in the predicted amplitudes of intense storms than the weaker storms. The results also show that some storms can be predicted up to 3 days before they are identified as an 850-hPa vorticity center in the analyses. In general, the results show a higher level of skill in the Northern Hemisphere (NH) than the Southern Hemisphere (SH); however, the rapid growth of NH winter storms is not very well predicted. The impact that observations of different types have on the prediction of the extratropical cyclones has also been explored, using forecasts integrated from analyses that were constructed from reduced observing systems. A terrestrial, satellite, and surface-based system were investigated and the results showed that the predictive skill of the terrestrial system was superior to the satellite system in the NH. Further analysis showed that the satellite system was not very good at predicting the growth of the storms. In the SH the terrestrial system has significantly less skill than the satellite system, highlighting the dominance of satellite observations in this hemisphere. The surface system has very poor predictive skill in both hemispheres.