Search results for "vector"
showing 10 items of 2660 documents
Advances in Kernel Machines for Image Classification and Biophysical Parameter Retrieval
2017
Remote sensing data analysis is knowing an unprecedented upswing fostered by the activities of the public and private sectors of geospatial and environmental data analysis. Modern imaging sensors offer the necessary spatial and spectral information to tackle a wide range problems through Earth Observation, such as land cover and use updating, urban dynamics, or vegetation and crop monitoring. In the upcoming years even richer information will be available: more sophisticated hyperspectral sensors with high spectral resolution, multispectral sensors with sub-metric spatial detail or drones that can be deployed in very short time lapses. Besides such opportunities, these new and wealthy infor…
West Nile virus in Spain: Forecasting the geographical distribution of risky areas with an ecological niche modelling approach.
2021
West Nile virus (WNV), a well-known emerging vector-borne arbovirus with a zoonotic life cycle, represents a threat to both public and animal health. Transmitted by ornithophilic mosquitoes, its transmission is difficult to predict and even more difficult to prevent. The massive and unprecedented number of human cases and equid outbreaks in Spain during 2020 interpellates for new approaches. For the first time, we present an integrate analysis from a niche perspective to provide an insight to the situation of West Nile disease (WND) in Spain. Our modelling approach benefits from the combined use of global occurrence records of outbreaks of WND in equids and of its two alleged main vectors i…
Impact of COVID-19 on the travel and tourism industry.
2021
Abstract Our paper is among the first to measure the potential effects of the COVID-19 pandemic on the tourism industry. Using panel structural vector auto-regression (PSVAR) (Pedroni, 2013) on data from 1995 to 2019 in 185 countries and system dynamic modeling (real-time data parameters connected to COVID-19), we estimate the impact of the pandemic crisis on the tourism industry worldwide. Past pandemic crises operated mostly through idiosyncratic shocks' channels, exposing domestic tourism sectors to large adverse shocks. Once domestic shocks perished (zero infection cases), inbound arrivals revived immediately. The COVID-19 pandemic, however, is different; and recovery of the tourism ind…
- EL EFECTO FISHER Y LA PARIDAD DE INTERÉS REAL. EVIDENCIA PARA LA ECONOMÍA ESPAÑOLA
1999
This paper provides an empirical test of the Fisher effect and of the real interest parity. The objetive is to determinate the behavior of the ex-ante real interest that condicionate the intertemporal savings and investment decisions. The method used is the time series properties of the data, which allows to separate estimation of the long-run equilibrium relationship from the nuisance parameters that characterize the short-run dynamics. The results find support inthe long run for a tax-adjusted Fisher hypothesis but not for the real interest parity. En este trabajo se contrasta empíricamente el cumplimiento de la hipótesis de Fisher y de la paridad de interés real para el caso español. El …
Weak versus strong dominance of shrinkage estimators
2021
We consider the estimation of the mean of a multivariate normal distribution with known variance. Most studies consider the risk of competing estimators, that is the trace of the mean squared error matrix. In contrast we consider the whole mean squared error matrix, in particular its eigenvalues. We prove that there are only two distinct eigenvalues and apply our findings to the James–Stein and the Thompson class of estimators. It turns out that the famous Stein paradox is no longer a paradox when we consider the whole mean squared error matrix rather than only its trace.
WEIGHTED-AVERAGE LEAST SQUARES (WALS): A SURVEY
2014
Model averaging has become a popular method of estimation, following increasing evidence that model selection and estimation should be treated as one joint procedure. Weighted- average least squares (WALS) is a recent model-average approach, which takes an intermediate position between frequentist and Bayesian methods, allows a credible treatment of ignorance, and is extremely fast to compute. We review the theory of WALS and discuss extensions and applications.
Real wages-employment relationship in Finnish manufacturing: a VAR approach
1991
Granger's concept of causality and the vector autoregressive(VAR) technique is used to investigate the real wages-employment relationship in Finnish manufacturing. The stationarity of the time series is examined and a number of co-integration tests for the adequacy of a pure VAR specification performed. The results using a bivariate VAR model based on a lag structure determined by Akaike's information criterion suggests that real wages Granger-cause employment. The slight non-constancy of the model suggests, however, that the conclusion concerning the nature of the real wages-emploment relationship should be treated with causion.
On the international co-movement of natural interest rates
2022
Using quarterly data for 10 OECD countries and the Euro area and a Kalman filtering technique, we investigate the international co-movement among natural interest rates. We show that the US is the main source of global spillovers and global/common factors appear to be key drivers of such co-movement. Indeed, global liquidity is a net transmitter of shocks, while quantitative easing (QE) and the US Dollar are net recipients of shocks. We also find that total spillovers among natural interest rates have been rising since the late nineties, spiking at around economic re-cessions, periods of US monetary policy tightening, the global financial crisis and the Eurozone sovereign debt crisis. From …
Fabric attractors in general triclinic flow systems and their application to high strain shear zones: A dynamical system approach
2007
High strain zones may deform by flow with a triclinic symmetry. This paper describes triclinic flow in a reference frame where Instantaneous Stretching Axes (ISA) are fixed. The operation of triclinic flow is described in two ways: first in terms of flow and the nature of flow eigenvectors and in the second part of the paper in terms of finite strain. In monoclinic flow, at least one of the eigenvectors of the flow coincides with one of the ISA and one or two of the eigenvectors act as attractors of foliation or lineation elements. In triclinic flow some flow eigenvectors are undefined since the two largest eigenvalues (controlling the flow) are imaginary. Imaginary eigenvalues are particul…
Backward spin polarizabilityγπof the proton
2002
Using the Mainz $48\mathrm{cm}\ensuremath{\emptyset}\ifmmode\times\else\texttimes\fi{}64\mathrm{cm}$ NaI(Tl) detector and the segmented G\"ottingen recoil detector SENECA in coincidence, Compton scattering by the proton at ${\ensuremath{\theta}}_{\ensuremath{\gamma}}^{\mathrm{lab}}=136\ifmmode^\circ\else\textdegree\fi{}$ has been measured at MAMI (Mainz) in the energy range from 200 to 470 MeV. The new data confirm the previous observation that there is a systematic discrepancy between MAMI and LEGS (Brookhaven) data leading to different spin polarizabilities ${\ensuremath{\gamma}}_{\ensuremath{\pi}}=\ensuremath{-}38.7\ifmmode\pm\else\textpm\fi{}1.8$ and $\ensuremath{-}27.2\ifmmode\pm\else\…