Juan-Miguel Lopez

Dr. Juan-Miguel Lopez


Research Focus & Metrics

Academic Career Length

22Years (2005-Present)

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

Representative Publications

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16 March 2024 in Universal Access in the Information Society
Verified
Journal Article
Open access
PDF file
JLJuan-Miguel Lopez
Juan-Miguel Lopez
JPJuanan Pereira
Juanan Pereira
Web accessibility evaluation is a costly process that usually requires manual intervention. Currently, large language model (LLM) based systems have gained popularity and shown promising capabilities to perform tasks that seemed impossible or required programming knowledge specific to a given area or were supposed to be impossible to be performed automatically. Our research explores whether an LLM-based system would be able to evaluate web accessibility success criteria that require manual evaluation. Three specific success criteria of the Web Content Accessibility Guidelines (WCAG) that currently require manual checks were tested: 1.1.1 Non-text Content, 2.4.4 Link Purpose (In Context), and 3.1.2 Language of Parts. LLM-based scripts were developed to evaluate the test cases. Results were compared against current web accessibility evaluators. While automated accessibility evaluators were unable to reliably test the three WCAG criteria, often missing or only warning about issues, the LLM-based scripts successfully identified accessibility issues the tools missed, achieving overall 87.18% detection across the test cases. Conclusion The results demonstrate LLMs can augment automated accessibility testing to catch issues that pure software testing misses today. Further research should expand evaluation across more test cases and types of content.

19 August 2016 in Frontiers in Computational Neuroscience
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Journal Article
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JLJuan-Miguel Lopez
Juan-Miguel Lopez
JGJordi Virgili Gomá
Jordi Virgili Gomá
Rosa Gil IranzoRosa Gil Iranzo
Rosa Gil Iranzo
RGRoberto García
Roberto García
TGTeresa Guilera
Teresa Guilera
JSJorge Soler-González
Jorge Soler-González
Technical advances, particularly the integration of wearable and embedded sensors, facilitate tracking of physiological responses in a less intrusive way. Currently, there are many devices that allow gathering biometric measurements from human beings, such as EEG Headsets or Health Bracelets. The massive data sets generated by tracking of EEG and physiology may be used, among other things, to infer knowledge about human moods and emotions. Apart from direct biometric signal measurement, eye tracking systems are nowadays capable of determining the point of gaze of the users when interacting in ICT environments, which provides an added value research on many different areas, such as psychology or marketing. We present a process in which devices for eye tracking, biometric and EEG signal measurements are synchronously used for studying both basic and complex emotions. We selected the least intrusive devices for different signal data collection given the study requirements and cost constraints, so users would behave in the most natural way possible. On the one hand, we have been able to determine basic emotions participants were experiencing by means of valence and arousal. On the other hand, a complex emotion such as empathy has also been detected. To validate the usefulness of this approach, a study involving 44 people has been carried out, where they were exposed to a series of affective stimuli while their EEG activity, biometric signals and eye position were synchronously recorded to detect self-regulation. The hypothesis of the work was that people who self regulated would show significantly different results when analyzing their EEG data. Participants were divided into two groups depending on whether Electro Dermal Activity (EDA) data indicated they self-regulated or not. The comparison of the results obtained using different machine learning algorithms for emotion recognition shows that using EEG activity alone as a predictor for self-regulation does not allow properly determining whether a person in self-regulation its emotions while watching affective stimuli. However, adequately combining different data sources in a synchronous way to detect emotions makes it possible to overcome the limitations of single detection methods.

1 January 2008
Verified
Book Chapter
Open access
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JLJuan-Miguel Lopez
Juan-Miguel Lopez
Rosa Gil IranzoRosa Gil Iranzo
Rosa Gil Iranzo
RGRoberto García
Roberto García
ICIdoia Cearreta
Idoia Cearreta
NGNestor Garay
Nestor Garay
The study of emotion in human beings has traditionally been a research interest area in disciplines such as psychology and sociology. The appearance of affective computing paradigm has made it possible to include findings from these disciplines in the development of affective interfaces. Still, there is a lack of applications that take emotion related aspects into account. This situation is mainly due to the great amount of proposed theoretical models and the complexity of human emotions. Besides, the importance that mobile computing area is acquiring has made necessary to bear context related aspects in mind. The proposal presented in this paper is based on a generic ontology for describing emotions and their detection and expression systems taking contextual and multimodal elements into account. The ontology is proposed as a way to develop a formal model that can be easily computerized. Moreover, it is based on a standard, the Web Ontology Language (OWL), which also makes ontologies easily shareable and extensible. Once formalized as an ontology, the knowledge about emotions is used in order to make computers more accessible, personalised and adapted to user needs.

15 June 2023 in Soft Computing
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Journal Article
Open access
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Rosa Gil IranzoRosa Gil Iranzo
Rosa Gil Iranzo
JGJordi Virgili Gomá
Jordi Virgili Gomá
JLJuan-Miguel Lopez
Juan-Miguel Lopez
RGRoberto García
Roberto García
This study conducts research on deepfakes technology evolution and trends based on a bibliometric analysis of the articles published on this topic along with six research questions: What are the main research areas of the articles in deepfakes? What are the main current topics in deepfakes research and how are they related? Which are the trends in deepfakes research? How do topics in deepfakes research change over time? Who is researching deepfakes? Who is funding deepfakes research? We have found a total of 331 research articles about deepfakes in an analysis carried out on the Web of Science and Scopus databases. This data serves to provide a complete overview of deepfakes. Main insights include: different areas in which deepfakes research is being performed; which areas are the emerging ones, those that are considered basic, and those that currently have the most potential for development; most studied topics on deepfakes research, including the different artificial intelligence methods applied; emerging and niche topics; relationships among the most prominent researchers; the countries where deepfakes research is performed; main funding institutions. This paper identifies the current trends and opportunities in deepfakes research for practitioners and researchers who want to get into this topic.

1 January 2005 in Lecture Notes in Computer Science
Verified
Book Chapter
Closed access
PDF file
ZOZeljko Obrenovic
Zeljko Obrenovic
NGNestor Garay
Nestor Garay
JLJuan-Miguel Lopez
Juan-Miguel Lopez
IFInmaculada Fajardo
Inmaculada Fajardo
ICIdoia Cearreta
Idoia Cearreta

25 December 2015 in Sensors
Verified
Journal Article
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AAAitor Alvarez
Aitor Alvarez
BSBasilio Sierra
Basilio Sierra
AAAndoni Arruti
Andoni Arruti
JLJuan-Miguel Lopez
Juan-Miguel Lopez
NGNestor Garay-Vitoria
Nestor Garay-Vitoria
In this paper, a new supervised classification paradigm, called classifier subset selection for stacked generalization (CSS stacking), is presented to deal with speech emotion recognition. The new approach consists of an improvement of a bi-level multi-classifier system known as stacking generalization by means of an integration of an estimation of distribution algorithm (EDA) in the first layer to select the optimal subset from the standard base classifiers. The good performance of the proposed new paradigm was demonstrated over different configurations and datasets. First, several CSS stacking classifiers were constructed on the RekEmozio dataset, using some specific standard base classifiers and a total of 123 spectral, quality and prosodic features computed using in-house feature extraction algorithms. These initial CSS stacking classifiers were compared to other multi-classifier systems and the employed standard classifiers built on the same set of speech features. Then, new CSS stacking classifiers were built on RekEmozio using a different set of both acoustic parameters (extended version of the Geneva Minimalistic Acoustic Parameter Set (eGeMAPS)) and standard classifiers and employing the best meta-classifier of the initial experiments. The performance of these two CSS stacking classifiers was evaluated and compared. Finally, the new paradigm was tested on the well-known Berlin Emotional Speech database. We compared the performance of single, standard stacking and CSS stacking systems using the same parametrization of the second phase. All of the classifications were performed at the categorical level, including the six primary emotions plus the neutral one.