María Dolores Ugarte

Prof. María Dolores Ugarte

orcid

Research Focus & Metrics

Academic Career Length

30Years (1997-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

View All Publications
21 March 2020 in Remote Sensing
Verified
Journal Article
Open access
PDF file
AMAna Militino
Ana Militino
MMMohammad Mehdi Moradi
Mohammad Mehdi Moradi
MUMaría Dolores Ugarte
María Dolores Ugarte
Detecting change-points and trends are common tasks in the analysis of remote sensing data. Over the years, many different methods have been proposed for those purposes, including (modified) Mann–Kendall and Cox–Stuart tests for detecting trends; and Pettitt, Buishand range, Buishand U, standard normal homogeneity (Snh), Meanvar, structure change (Strucchange), breaks for additive season and trend (BFAST), and hierarchical divisive (E.divisive) for detecting change-points. In this paper, we describe a simulation study based on including different artificial, abrupt changes at different time-periods of image time series to assess the performances of such methods. The power of the test, type I error probability, and mean absolute error (MAE) were used as performance criteria, although MAE was only calculated for change-point detection methods. The study reveals that if the magnitude of change (or trend slope) is high, and/or the change does not occur in the first or last time-periods, the methods generally have a high power and a low MAE. However, in the presence of temporal autocorrelation, MAE raises, and the probability of introducing false positives increases noticeably. The modified versions of the Mann–Kendall method for autocorrelated data reduce/moderate its type I error probability, but this reduction comes with an important power diminution. In conclusion, taking a trade-off between the power of the test and type I error probability, we conclude that the original Mann–Kendall test is generally the preferable choice. Although Mann–Kendall is not able to identify the time-period of abrupt changes, it is more reliable than other methods when detecting the existence of such changes. Finally, we look for trend/change-points in land surface temperature (LST), day and night, via monthly MODIS images in Navarre, Spain, from January 2001 to December 2018.

30 March 2017 in Stochastic Environmental Research and Risk Assessment
Verified
Journal Article
Closed access
PDF file
TGTomas Goicoa
Tomas Goicoa
AAAritz Adin
Aritz Adin
MUMaría Dolores Ugarte
María Dolores Ugarte
JHJ. S. Hodges
J. S. Hodges

7 April 2014 in Statistical Methods in Medical Research
Verified
Journal Article
Closed access
MUMaría Dolores Ugarte
María Dolores Ugarte
AAAritz Adin
Aritz Adin
TGTomas Goicoa
Tomas Goicoa
AMAna Fernandez Militino
Ana Fernandez Militino
Spatio-temporal disease mapping comprises a wide range of models used to describe the distribution of a disease in space and its evolution in time. These models have been commonly formulated within a hierarchical Bayesian framework with two main approaches: an empirical Bayes (EB) and a fully Bayes (FB) approach. The EB approach provides point estimates of the parameters relying on the well-known penalized quasi-likelihood (PQL) technique. The FB approach provides the posterior distribution of the target parameters. These marginal distributions are not usually available in closed form and common estimation procedures are based on Markov chain Monte Carlo (MCMC) methods. However, the spatio-temporal models used in disease mapping are often very complex and MCMC methods may lead to large Monte Carlo errors and a huge computation time if the dimension of the data at hand is large. To circumvent these potential inconveniences, a new technique called integrated nested Laplace approximations (INLA), based on nested Laplace approximations, has been proposed for Bayesian inference in latent Gaussian models. In this paper, we show how to fit different spatio-temporal models for disease mapping with INLA using the Leroux CAR prior for the spatial component, and we compare it with PQL via a simulation study. The spatio-temporal distribution of male brain cancer mortality in Spain during the period 1986–2010 is also analysed.

1 March 2001 in Biometrics
Verified
Journal Article
Closed access
PDF file
CDC. B. Dean
C. B. Dean
MUMaría Dolores Ugarte
María Dolores Ugarte
AMAna Militino
Ana Militino

3 July 2009 in Environmetrics
Verified
Journal Article
Closed access
PDF file
MUMaría Dolores Ugarte
María Dolores Ugarte
TGTomas Goicoa
Tomas Goicoa
AMA. F. Militino
A. F. Militino

1 September 2004 in The Journal of Real Estate Finance and Economics
Verified
Journal Article
Closed access
PDF file
AMAna Militino
Ana Militino
MUMaría Dolores Ugarte
María Dolores Ugarte
LGL. García-Reinaldos
L. García-Reinaldos