Francisco A. Ocaña

Yield and composition of the essential oil of Thymus serpylloides subsp. serpylloides

Abstract The difference in yield and composition of essential oil of Thymus serpylloides subsp. serpylloides (‘thyme of the Sierra’) has been investigated. The research included all of its different phonological stages, its sexual characteristics, during three consecutive years. Quantitative analysis of the essential oil revealed that there is a predominance of both aromatic alcohols (carvacrol being the most abundant component in this group) and their precursors (γ-terpinene and p -cymene).

AN APPROXIMATED PRINCIPAL COMPONENT PREDICTION MODEL FOR CONTINUOUS-TIME STOCHASTIC PROCESSES

SUMMARY In this paper, a linear model for forecasting a continuous-time stochastic process in a future interval in terms of its evolution in a past interval is developed. This model is based on linear regression of the principal components in the future against the principal components in the past. In order to approximate the principal factors from discrete observations of a set of regular sample paths, cubic spline interpolation is used. An application for forecasting tourism evolution in Granada is also included. ( 1997 by John Wiley & Sons, Ltd.

Forecasting with unequally spaced data by a functional principal component approach

The Principal Component Regression model of multiple responses is extended to forccast a continuous-time stochastic process. Orthogonal projection on a subspace of trigonometric functions is applied in order to estimate the principal components using discrete-time observations from a sample of regular curves. The forecasts provided by this approach are compared with classical principal component regression on simulated data.

LAS ELECCIONES AUTONÓMICAS DE 1999 Y LAS ESPAÑAS ELECTORALES

En las siguientes paginas se estudian las principales caracteristicas de los sistemas y subsistemas de partidos surgidos de la ultima convocatoria electoral de caracter autonomico. Se analizan los datos que en cada Comunidad Autonoma alcanzan la fragmentacion, el numero de partidos, la concentracion, la competitividad, la polarizacion y la volatilidad, y se comparan con los valores que estas dimensiones alcanzan en otras Comunidades Autonomas, asi como con los registrados en anteriores convocatorias. En la conclusion se senalan los distintos sistemas y subsistemas, modelo general y excentricos, que pueden distinguirse en atencion a las respectivas caracteristicas de las pautas de la competicion partidista y electoral en estas plurales arenas electorales.

Forecasting Pollen Concentration by a Two‐Step Functional Model

A functional regression model to forecast the cypress pollen concentration during a given time interval, considering the air temperature in a previous interval as the input, is derived by means of a two-step procedure. This estimation is carried out by functional principal component (FPC) analysis and the residual noise is also modeled by FPC regression, taking as the explicative process the pollen concentration during the earlier interval. The prediction performance is then tested on pollen data series recorded in Granada (Spain) over a period of 10 years.

Forecasting PC-ARIMA Models for Functional Data

This paper introduces an improvement on the forecasting models previously developed by the authors for continuous time series based on the PCA of the stochastic process by cutting series in seasonal periods. The new approach consists of modelling principal components as ARIMA processes and then to formulate a mixed PC-ARIMA model for the time series. This methodology is then applied to the climatic phenomenon known as El Nino.

Stochastic modelling for evolution of stock prices by means of functional principal component analysis

The objective of this paper is to apply functional principal component analysis to model and forecast financial prices of the banking in Madrid Stock Market from weekly observations of a random sample of banks. It is well known that direct statistical analysis of stock prices is difficult, therefore principal component prediction models for weekly returns are performed to give appropriate forecasts for prices. Copyright

Variations in yield and composition of the essential oil of Satureja obovat

Abstract The difference in yield and composition of the essential oil of Satureja obovata (‘savory’) has been investigated. The research included all of its different phonological stages, in several populations of the provinces of Granada and Malaga, during three consecutive years. Quantitative analysis of the essential oil revealed the existence of two distinct groups of samples depending on their major components: (i) oxygenated monoterpenic derivatives and (ii) aromatic alcohols and their precursors.

Índices e indicadores del sistema electoral y del sistema de partidos: una propuesta informática para su cálculo

En estas paginas se presenta un programa informatico que estara a disposicion de los usuarios en la pagina web del CIS a partir del proximo 1 de octubre. Con el programa INDELEC pueden calcularse los mas importantes indices de desproporcionalidad de los sistemas electorales, asi como los mas comunes para conocer las dimensiones de los sistemas de partidos: fragmentacion, numero de partidos, concentracion, competitividad, polarizacion, volatilidad, voto regional y voto dual. En este articulo, y a modo de ejemplo, se aplica el programa INDELEC a los resultados agregados de las elecciones al Congreso de los Diputados celebradas en Espana desde 1977. En una monografia que, con el titulo Analisis electoral, vera la luz en el mes de septiembre en la coleccion Cuadernos Metodologicos del CIS, se analiza detenidamente cada indicador, apuntando sus ventajas e inconvenientes, y se aplican a las sucesivas convocatorias de los diversos tipos de elecciones celebradas en nuestro pais desde la reinstauracion de la democracia y en distinto nivel de agregacion y desagregacion. Dibujamos, de esta forma, un mapa con las principales caracteristicas de los diversos sistemas y subsistemas (estatales y autonomicos) de partidos habidos en Espana desde 1977.

Estimation of Functional Regression Models for Functional Responses by Wavelet Approximation

A linear regression model to estimate a sample of response curves (realizations of a functional response) from a sample of predictor curves (functional predictor) is considered. Di erent procedures for estimating the parameter function of the model based on wavelets expansions and functional principal component decomposition of both the predictor and response curves are proposed. Wavelets coe cients will be estimated from discrete observations of sample curves at irregularly spaced time points that could be di erent among sample individuals.