Search results for "Series"
showing 10 items of 1193 documents
Latent force models for earth observation time series prediction
2016
We introduce latent force models for Earth observation time series analysis. The model uses Gaussian processes and differential equations to combine data driven modelling with a physical model of the system. The LFM presented here performs multi-output structured regression, adapts to the signal characteristics, it can cope with missing data in the time series, and provides explicit latent functions that allow system analysis and evaluation. We successfully illustrate the performance in challenging scenarios of crop monitoring from space, providing time-resolved time series predictions.
Testing Multi-Sensors Time Series of Lai Estimates to Monitor Rice Phenology: Preliminary Results
2018
Timely and accurate information on crop growth and seasonal dynamics are increasingly needed to develop monitoring systems aimed to detect seasonal anomalies, support site specific management and estimate crop yield at the end of the season. In particular, frequent decametric information nowadays being provided exploiting the new generation of Earth Observation (EO) platforms are fundamental for farm level monitoring. This study presents an analysis aimed at fully exploiting dense time series of EO data derived from the combined use of ESA Sentinel-2A and NASA Landsat-7/8 imageries for crop phenological monitoring. Decametric Leaf Area Index (LAI) maps were generated for the year 2016 by in…
Does politics matter in the conduct of fiscal policy? Political determinants of the fiscal sustainability: Evidence from seven individual Central and…
2007
This paper aims at assessing the fiscal sustainability and its political determinants in seven Central and Eastern European Countries (CEEC), namely Estonia, Latvia, Lithuania, Poland, Slovenia, Slovakia and the Czech Republic. First, using the recent sustainability approach of Bohn (1998) based on fiscal reaction function, econometric findings using Ordinary Least Squares (OLS) reveal a positive response of the primary surplus to changes in debt in several countries. In other words, fiscal policy is sustainable in Baltic countries, Slovenia and Slovakia, but not in Poland and in the Czech Republic. Second, by introducing political dummy variables, we test the electoral budget cycle and the…
Survey on the innovation in the Sicilian grapevine nurseries
2012
This paper deals with quality innovation in the grapevine nursery sector. The vegetative propagation of grapevines, scarcely considered by economic research, is the first step in the wine production chain as it influences both the type and the quality of wines as well as the quality and quantity of the performance of farm investments.This paper gives the results of a study carried out through a structural analysis of both national and regional grapevine nurseries and then through a direct survey of the largest Sicilian nurseries. The survey covers the main structural and productive issues as well as the commercial aspects of eight Sicilian grapevine nurseries and their innovative investment…
Integrated capital shares
2019
In empirical macroeconomics, inter-dependencies between countries are often analysed using cross-country correlations or graphical investigation of time series. This study shows that applying an alternative methodological approach - identification of common unobservable factors and using them as explanatory variables for country-specific time series - indicates a stronger cross-country integration of functional income distributions than the standard methods. The results vary only little between different samples, where both the country and year coverage change. Moreover, the main findings are not sensitive to the way capital depreciation is taken into account. The primary driving factor see…
Rolling over stock index futures contracts
2009
Derivative contracts have a finite life limited by their maturity. The construction of continuous series, however, is crucial for academic and trading purposes. In this study, we analyze the relevance of the choice of the rollover date, defined as the point in time when we switch from the front contract series to the next one. We have used five different methodologies in order to construct five different return series of stock index futures contracts. The results show that, regardless of the criterion applied, there are not significant differences between the resultant series. Therefore, the least complex method can be used in order to reach the same conclusions. © 2009 Wiley Periodicals, I…
Model Based Monte Carlo Pricing of Energy and Temperature Quanto Options
2010
Weather derivatives have become very popular tools in weather risk management in recent years. One of the elements supporting their diffusion has been the increase in volatility observed on many energy markets. Among the several available contracts, Quanto options are now becoming very popular for a simple reason: they take into account the strong correlation between energy consumption and certain weather conditions, so enabling price and weather risk to be controlled at the same time. These products are more efficient and, in many cases, significantly cheaper than simpler plain vanilla options. Unfortunately, the specific features of energy and weather time series do not enable the use of …
¿SE PUEDE MEDIR LA NEGOCIACIÓN INFORMADA?: UNA REVISIÓN DE LA METODOLOGÍA BASADA EN LAS COVARIANZAS DE LAS SERIES DE PRECIOS
2009
RESUMENEl desarrollo en los modelos teóricos de microestructura ha motivado la aparición de un grupo de trabajos encaminado al estudio empírico de los costes de transacción y sus componentes dada la importancia que han tenido los mismos en el estudio del funcionamiento de los mercados y la comparación entre éstos así como sus numerosas aplicaciones en campos afines (finanzas corporativas, eficiencia de los mercados, etc.). Por otra parte, la contrastación empírica de los distintos modelos establecidos muestra resultados claramente dispares. Por ello, el objetivo de nuestro trabajo es analizar con detalle y en conjunto dichos modelos centrándonos en un grupo con características muy similares…
A critical view on temperature modelling for application in weather derivatives markets
2012
In this paper we present a stochastic model for daily average temperature. The model contains seasonality, a low-order autoregressive component and a variance describing the heteroskedastic residuals. The model is estimated on daily average temperature records from Stockholm (Sweden). By comparing the proposed model with the popular model of Campbell and Diebold (2005), we point out some important issues to be addressed when modelling the temperature for application in weather derivatives market.
Educational attainment in the OECD, 1960-2010. Updated series and a comparison with other sources
2015
© 2015 Elsevier Ltd. This paper describes the construction of updated series on the educational attainment of the adult population for a sample of 22 OECD countries covering the period 1960-2010. These series are then compared with (the OECD subsample of) the latest available version of other cross-country data sets on average years of schooling that are commonly used in the literature. Finally, statistical measures of the information content of the different series are constructed using the procedure developed by Krueger and Lindhal (K&L, 2001) and de la Fuente and Doménech (D&D, 2006). The exercise shows that there are important differences in quality across data sets and suggests that su…