Rafael del-Hoyo-Alonso

Rafael del-Hoyo-Alonso


Research Focus & Metrics

Academic Career Length

26Years (2001-Present)

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

Representative Publications

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1 August 2016 in Fuel
Verified
Journal Article
Closed access
MMMario Miana
Mario Miana
RDRafael del-Hoyo-Alonso
Rafael del-Hoyo-Alonso
VRVega Rodrigálvarez
Vega Rodrigálvarez

RARocío Aznar-Gimeno
Rocío Aznar-Gimeno
Luis Mariano EstebanLuis Mariano Esteban
Luis Mariano Esteban
GLGorka Labata-Lezaun
Gorka Labata-Lezaun
RDRafael del-Hoyo-Alonso
Rafael del-Hoyo-Alonso
DADavid Abadia-Gallego
David Abadia-Gallego
MSM. Trinidad Serrano
M. Trinidad Serrano
The purpose of the study was to build a predictive model for estimating the risk of ICU admission or mortality among patients hospitalized with COVID-19 and provide a user-friendly tool to assist clinicians in the decision-making process. The study cohort comprised 3623 patients with confirmed COVID-19 who were hospitalized in the SALUD hospital network of Aragon (Spain), which includes 23 hospitals, between February 2020 and January 2021, a period that includes several pandemic waves. Up to 165 variables were analysed, including demographics, comorbidity, chronic drugs, vital signs, and laboratory data. To build the predictive models, different techniques and machine learning (ML) algorithms were explored: multilayer perceptron, random forest, and extreme gradient boosting (XGBoost). A reduction dimensionality procedure was used to minimize the features to 20, ensuring feasible use of the tool in practice. Our model was validated both internally and externally. We also assessed its calibration and provide an analysis of the optimal cut-off points depending on the metric to be optimized. The best performing algorithm was XGBoost. The final model achieved good discrimination for the external validation set (AUC = 0.821, 95% CI 0.787–0.854) and accurate calibration (slope = 1, intercept = −0.12). A cut-off of 0.4 provides a sensitivity and specificity of 0.71 and 0.78, respectively. In conclusion, we built a risk prediction model from a large amount of data from several pandemic waves, which had good calibration and discrimination ability. We also created a user-friendly web application that can aid rapid decision-making in clinical practice.

19 June 2021 in Entropy
Verified
Journal Article
Open access
PDF file
RARocío Aznar-Gimeno
Rocío Aznar-Gimeno
GLGorka Labata-Lezaun
Gorka Labata-Lezaun
AAAna Adell
Ana Adell
DADavid Abadia-Gallego
David Abadia-Gallego
RDRafael del-Hoyo-Alonso
Rafael del-Hoyo-Alonso
CGCarlos González
Carlos González
The increase in the proportion of elderly in Europe brings with it certain challenges that society needs to address, such as custodial care. We propose a scalable, easily modulated and live assistive technology system, based on a comfortable smart footwear capable of detecting walking behaviour, in order to prevent possible health problems in the elderly, facilitating their urban life as independently and safety as possible. This brings with it the challenge of handling the large amounts of data generated, transmitting and pre-processing that information and analysing it with the aim of obtaining useful information in real/near-real time. This is the basis of information theory. This work presents a complete system aiming at elderly people that can detect different user behaviours/events (sitting, standing without imbalance, standing with imbalance, walking, running, tripping) through information acquired from 20 types of sensor measurements (16 piezoelectric pressure sensors, one accelerometer returning reading for the 3 axis and one temperature sensor) and warn the relatives about possible risks in near-real time. For the detection of these events, a hierarchical structure of cascading binary models is designed and applied using artificial neural network (ANN) algorithms and deep learning techniques. The best models are achieved with convolutional layered ANN and multilayer perceptrons. The overall event detection performance achieves an average accuracy and area under the ROC curve of 0.84 and 0.96, respectively.

29 May 2020
Verified
Book Chapter
Open access
PDF file
Dimosthenis KyriazisDimosthenis Kyriazis
Dimosthenis Kyriazis
OBOfer Biran
Ofer Biran
TBThanassis Bouras
Thanassis Bouras
KBKlaus Brisch
Klaus Brisch
ADArmend Duzha
Armend Duzha
PTPANAYIOTIS TSANAKAS
PANAYIOTIS TSANAKAS
While several application domains are exploiting the added-value of analytics over various datasets to obtain actionable insights and drive decision making, the public policy management domain has not yet taken advantage of the full potential of the aforementioned analytics and data models. Diverse and heterogeneous datasets are being generated from various sources, which could be utilized across the complete policies lifecycle (i.e. modelling, creation, evaluation and optimization) to realize efficient policy management. To this end, in this paper we present an overall architecture of a cloud-based environment that facilitates data retrieval and analytics, as well as policy modelling, creation and optimization. The environment enables data collection from heterogeneous sources, linking and aggregation, complemented with data cleaning and interoperability techniques in order to make the data ready for use. An innovative approach for analytics as a service is introduced and linked with a policy development toolkit, which is an integrated web-based environment to fulfil the requirements of the public policy ecosystem stakeholders. Keywords Data analytics as a service Public policies Cloud computing Policy modelling

1 November 2013
Verified
Conference Paper
Closed access
PPPaula Penas
Paula Penas
RDRafael del-Hoyo-Alonso
Rafael del-Hoyo-Alonso
JVJorge Vea-Murguia
Jorge Vea-Murguia
CGCarlos Gonzalez
Carlos Gonzalez
SMSergio Mayo
Sergio Mayo
How to model user interests and intentions through user profiling is an important key for providing personalized service on Internet. User profiling can be seen as the inference of user interests, intentions, characteristics, behaviors and preferences. This paper introduces a scalable and automated technique for user profiling by extracting his URLs from publicly available tweets information and using a semantic ontology in which user interests and intentions are characterized. In order to enhance the performance of our method, categorization of websites offered by OpenDNS and DBpedia collective knowledge databases are used to find the interests and intention categories of the user profile ontology. In this context, user profile ontology is populated taking these collective categories and with assertions of individuals, and relationships of interest and intention. As new concepts and relationships are defined and inferred, user profile ontology evolves continuously. Experimental results based on user's tweets confirm strongly that the proposed method improves the automatic acquisition of interests and intentions of a user profile.

1 February 2023 in Plants
Verified
Journal Article
Open access
PDF file
Joaquín Balduque-GilJoaquín Balduque-Gil
Joaquín Balduque-Gil
FPFrancisco José Lacueva Pérez
Francisco José Lacueva Pérez
GLGorka Labata-Lezaun
Gorka Labata-Lezaun
RDRafael del-Hoyo-Alonso
Rafael del-Hoyo-Alonso
Sergio IlarriSergio Ilarri
Sergio Ilarri
JBJuan J. Barriuso-Vargas
Juan J. Barriuso-Vargas
Machine Learning (ML) techniques can be used to convert Big Data into valuable information for agri-environmental applications, such as predictive pest modeling. Lobesia botrana (Denis & Schiffermüller) 1775 (Lepidoptera: Tortricidae) is one of the main pests of grapevine, causing high productivity losses in some vineyards worldwide. This work focuses on the optimization of the Touzeau model, a classical correlation model between temperature and L. botrana development using data-driven models. Data collected from field observations were combined with 30 GB of registered weather data updated every 30 min to train the ML models and make predictions on this pest’s flights, as well as to assess the accuracy of both Touzeau and ML models. The results obtained highlight a much higher F1 score of the ML models in comparison with the Touzeau model. The best-performing model was an artificial neural network of four layers, which considered several variables together and not only the temperature, taking advantage of the ability of ML models to find relationships in nonlinear systems. Despite the room for improvement of artificial intelligence-based models, the process and results presented herein highlight the benefits of ML applied to agricultural pest management strategies.