José Francisco Vélez

Prof. José Francisco Vélez

orcid

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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20 January 2003
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Conference Paper
Closed access
BMB. Moreno
B. Moreno
ASA. Sanchez
A. Sanchez
JVJosé Francisco Vélez
José Francisco Vélez

1 September 2006 in Engineering Applications of Artificial Intelligence
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Journal Article
Closed access
EFE. Frias-Martinez
E. Frias-Martinez
ASAngel Sanchez
Angel Sanchez
JVJosé Francisco Vélez
José Francisco Vélez

1 January 2020 in Neurocomputing
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Journal Article
Closed access
VRVictoria Ruiz
Victoria Ruiz
ILIsmael Linares
Ismael Linares
ASAngel Sanchez
Angel Sanchez
JVJosé Francisco Vélez
José Francisco Vélez

15 August 2020 in Sensors
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Journal Article
Open access
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ÁMÁngel Morera
Ángel Morera
ASAngel Sanchez
Angel Sanchez
AMA. Belén Moreno
A. Belén Moreno
ASAngel Sappa
Angel Sappa
JVJosé Francisco Vélez
José Francisco Vélez
This work compares Single Shot MultiBox Detector (SSD) and You Only Look Once (YOLO) deep neural networks for the outdoor advertisement panel detection problem by handling multiple and combined variabilities in the scenes. Publicity panel detection in images offers important advantages both in the real world as well as in the virtual one. For example, applications like Google Street View can be used for Internet publicity and when detecting these ads panels in images, it could be possible to replace the publicity appearing inside the panels by another from a funding company. In our experiments, both SSD and YOLO detectors have produced acceptable results under variable sizes of panels, illumination conditions, viewing perspectives, partial occlusion of panels, complex background and multiple panels in scenes. Due to the difficulty of finding annotated images for the considered problem, we created our own dataset for conducting the experiments. The major strength of the SSD model was the almost elimination of False Positive (FP) cases, situation that is preferable when the publicity contained inside the panel is analyzed after detecting them. On the other side, YOLO produced better panel localization results detecting a higher number of True Positive (TP) panels with a higher accuracy. Finally, a comparison of the two analyzed object detection models with different types of semantic segmentation networks and using the same evaluation metrics is also included.

1 January 2005 in 2007 5th International Symposium on Image and Signal Processing and Analysis
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Conference Paper
Closed access
AMA.B. Moreno
A.B. Moreno
ASAngel Sanchez
Angel Sanchez
JVJosé Francisco Vélez
José Francisco Vélez
JDJ. Diaz
J. Diaz
Thirty local geometrical features extracted from 3D hitman face surfaces have been used to model the face for face recognition. They are the most discriminating ones selected from a set of 86. We have experimented with 420 3D-facial meshes (without texture) of 60 individuals. There are 7 images per subject including views presenting fight rotations and facial expressions. The HK algorithm, based in the signs of the mean and Gaussian curvatures, has been used for region segmentation. Experiments under controlled and non-controlled acquisition conditions, considering pose variations and facial expressions, have been achieved to analyze the robustness of the selected characteristics. Success recognition results of 82.0% and 90.16% were obtained when the images are frontal views with neutral expression using PCA and SVM, respectively. The recognition rates only decrease to 76.2% and 77.9% using PCA and SVM matching schemes respectively, under gesture and light face rotation.

7 June 2017 in PLOS ONE
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Journal Article
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JVJosé Francisco Vélez
José Francisco Vélez
DVDaniel Velez-Serrano
Daniel Velez-Serrano
VHValentin Hernandez-Barrera
Valentin Hernandez-Barrera
RGRodrigo Jiménez Garcia
Rodrigo Jiménez Garcia
Ana Lopez-de-AndresAna Lopez-de-Andres
Ana Lopez-de-Andres
AMAlejandro Alvaro Meca
Alejandro Alvaro Meca
One reason for the aggressiveness of the pancreatic cancer is that it is diagnosed late, which often limits both the therapeutic options that are available and patient survival. The long-term survival of pancreatic cancer patients is not possible if the tumor is not resected, even among patients who receive chemotherapy in the earliest stages. The main objective of this study was to create a prediction model for in-hospital mortality after a pancreatectomy in pancreatic cancer patients. We performed a retrospective study of all pancreatic resections in pancreatic cancer patients in Spanish public hospitals (2013). Data were obtained from records in the Minimum Basic Data Set. To develop the prediction model, we used a boosting method. The in-hospital mortality of pancreatic resections in pancreatic cancer patients was 8.48% in Spain. Our model showed high predictive accuracy, with an AUC of 0.91 and a Brier score of 0.09, which indicated that the probabilities were well calibrated. In addition, a sensitivity analysis of the information available prior to the surgery revealed that our model has high predictive accuracy, with an AUC of 0.802. In this study, we developed a nation-wide system that is capable of generating accurate and reliable predictions of in-hospital mortality after pancreatic resection in patients with pancreatic cancer. Our model could help surgeons understand the importance of the patients’ characteristics prior to surgery and the health effects that may follow resection.