39936 research outputs found
Sort by
Music and Oral and Written Expression Techniques at the Service of the Elderly : Volunteering Program
Full text linkAn approximate model for the computation of in-orbit collision probabilities using importance sampling
No full textThe risk of orbital collisions is at an all-time high. Standard methods which compute the probability of collision (PoC) often make restrictive assumptions which produce numerically efficient solutions, the quality of which may decrease over long time-spans. The crude Monte Carlo (CMC) simulation makes few assumptions and can produce high quality estimates; however, its computational cost can be prohibitively high. We introduce a new method based on importance sampling (IS), which aims to attain the accuracy of a CMC simulation at a fraction of the computational cost. To accomplish this, we propose a surrogate dynamical model which exploits Keplerian conjunction geometry and applies a linear correction to approximate the full-dynamics of the conjunction scenario, reducing the computational load of evaluating the dynamical model. This linear approximation is satisfactorily validated by means of high-fidelity model evaluations.This work has been supported by Comunidad de Madrid (project Ref. IND2020/TIC-17539) and Spain’s Agencia Estatal de Investigación (Ref. PID2021-125159NB-I00 TYCHE) funded by MCIN/AEI/10.13039/501100011033 and by “ERDF A way of making Europe”. JM also acknowledges the support of the Office of Naval Research (grant award N00014-22–1-2647)
Authenticity at Risk: Key Factors in the Generation and Detection of Audio Deepfakes
No full textDetecting audio deepfakes is crucial to ensure authenticity and security, especially in contexts where audio veracity can have critical implications, such as in the legal, security or human rights domains. Various elements, such as complex acoustic backgrounds, enhance the realism of deepfakes; however, their effect on the processes of creation and detection of deepfakes remains under-explored. This study systematically analyses how factors such as the acoustic environment, user type and signal-to-noise ratio influence the quality and detectability of deepfakes. For this study, we use the WELIVE dataset, which contains audio recordings of 14 female victims of gender-based violence in real and uncontrolled environments. The results indicate that the complexity of the acoustic scene affects both the generation and detection of deepfakes: classifiers, particularly the linear SVM, are more effective in complex acoustic environments, suggesting that simpler acoustic environments may facilitate the generation of more realistic deepfakes and, in turn, make it more difficult for classifiers to detect them. These findings underscore the need to develop adaptive models capable of handling diverse acoustic environments, thus improving detection reliability in dynamic and real-world contexts.This work is part of the project Vital-IoT funded by INCIBE (Ministry of Digital Transformation and Public Function) and the European Union NextGenerationEU in the framework of the Recovery and Resilience Facility (RRF) and Grant PID2021-125780NB-I00 funded by the Spanish Ministerio de Ciencia, Innovación y Universidades MICIU/AEI/10.13039/501100011033 and by “ERDF/EU
On the importance of strain rate dependence in high velocity impacts of woven CFRP fragments: Experimental and numerical methodology
Full text linkThis work presents a novel combined experimental–numerical methodology to analyse the behaviour of carbon/epoxy woven fragments, when impacting a rigid target at high velocity (up to 160 m/s). On the one hand, the experimental methodology developed is capable of measuring the impact force using a Hopkinson bar device; the images obtained by means of ultra-high speed cameras are used to analyse the different failure modes during the fracture process, providing a better understanding of the physical phenomena. On the other hand, a numerical methodology is developed to highlight the importance of considering the strain rate dependence in the constitutive model and to demonstrate the significant influence it has on the behaviour of CFRP fragments during the impact. Using this combined approach, it is possible to unveil the different roles of the damage mechanisms that appear in the CFRP fragment, and how they influence the impact force and impulse exerted; the inclusion of the strain rate dependence in the material model not only provides an increase in strength but also controls the failure mode. Finally, thanks to the numerical approach, a parametric study of fragment misalignment is carried out to present its influence on the failure mechanisms and in the results of force and impulse. The conclusions drawn represent a significant improvement in the understanding of the behaviour of composite materials acting as projectiles.The research leading to the developments described was funded within the framework of the projects: the Vicerrectorado de Política Científica project from the University Carlos III of Madrid, Spain 2013/00413/004, 2023/00264/001 and 2020/00123/001. This work has been supported by the AGENCIA ESTATAL DE INVESTIGACION (AEI), Spain under the grant number PID2021-125659OB-I00
Exploring the market opportunities of electrodynamic tethers for deorbiting and in-orbit-servicing
No full textProceedings of: 9th European Conference on Space Debris, 1 - 4 April 2025, Bonn, GermanyElectroDynamic Tethers (EDTs) provide a sustainable, propellant-free solution for propulsion and autonomous space deorbiting. This paper conducts a survey of interesting EDT applications, focusing on two key sectors: satellite and rocket body deorbiting, and In-Orbit Servicing (IoS). The analysis identifies significant growth in Low Earth Orbit (LEO) satellite launches projected through 2033. Currently, 74% of active LEO satellites under 70 kg lack propulsion systems. Conversely, 85% of satellites between 70-210 kg, and 96% of satellites over 200 kg, have propulsion systems. Despite propulsion availability, more than 40% of satellites as of 2022 failed to comply with the 25-year deorbit guideline. Rocket bodies showed better compliance, with only 7% not meeting regulations. However, the introduction of stricter 5 year deorbit rules in the US and Europe dramatically increases the demand for effective deorbit solutions. Within the IoS market, Life Extension Solutions represent 47% of projected revenue, while Active Debris Removal accounts for 26%. This paper explores EDTs’ potential within these markets, also summarizing recent advancements in EDTs under the E.T.PACK-F and E.T.COMPACT projects.This work is developed within the framework of the European Innovation Council Pathfinder project E.T.COMPACT (Project Number: 101161603), funded by the Horizon Europe research and innovation program of the European Union
Photojournalist Framing in the Ecological Crisis: The DANA Flood Coverage
Full text linkThis research focuses on current photojournalism practices in the media representation of the climate crisis, exploring how images published by Spain's leading digital newspapers contribute to shaping public perception of the phenomenon. Through a mixedmethods approach, this study examines eco-visual reporting in 2023 - a year characterized by unprecedented global temperatures - alongside an examination of the initial month of coverage of the 2024 DANA floods. The main objective of this study is to evaluate whether the visual depiction of climate change in mainstream media aligns with or deviates from the established visual patterns associated with stereotyped iconography and alarmist narratives. This research provides a taxonomy of the predominant thematic elements and their frequency, addressing key issues such as the persistence of worn-out visual tropes, the reliance on stock images, and the episodic nature of its news treatment. The inclusion of the most catastrophic climate disaster of the 21st century in Spain allows for an exploration of how the media pressure inherent to crisis situations intensifies the risk of errors in image attribution and contextualization. Finally, we offer practical recommendations to guide visual coverage toward comprehensive, accurate, and human-centered approaches, aiming to foster public trust and maximize the potential of photojournalism as a key tool in collective mobilization against the climate emergency.This research is supported by Iberifier, the Iberian Digital Media Observatory, co-funded by the European Commission (DIGITAL-2023-DEPLOY-04, Reference: IBERIFIER Plus–101158511), the Section 5 of Digital Communication and Culture at the Spanish Association for Communication Research (AE-IC), and the Climate Strategic Initiative (UC3M)
Parental vaccine hesitancy: Recent evidences support the need to implement targeted communication strategies
Full text linkIn 2018, Europe experienced a surge in measles cases, revealing the consequences of suboptimal immunization coverage. This trend was exacerbated by long-standing vaccine hesitancy. Parental attitudes toward childhood vaccines have increasingly shifted, influenced by ethical, religious, and safety concerns. Vaccines hesitancy has substantially increased after the Covid-19 pandemic. Using PubMed, we reviewed cross-sectional studies, published during years 2023-2024, related to parents' vaccine hesitancy, with the aim to provide an overview of its prevalence, underlying reasons and consequences for public health. Data summarised highlight various factors contributing to vaccine hesitancy. These include socio-demographic factors, the impact of the Covid-19 pandemic, and widespread misinformation, particularly through social media. Several cross-sectional studies show that vaccine hesitancy is often linked to lower education levels, misinformation, and decreased trust in healthcare systems. The pandemic exacerbated this issue. This article underscores the need for targeted communication strategies to address vaccine hesitancy, focusing on specific populations, such as those in low-income settings or with limited access to healthcare information. It emphasizes the importance of countering misinformation to improve vaccination rates and public health outcomes
Close contact for context: Qualitative methodological considerations for assessing prominence and discoverability
Full text linkThis article advocates for a "close contact for context" approach as a crucial step before, or in combination with, automated data collection and comparative analyses to assess the prominence and discoverability of European works in video-on-demand (VoD) catalogs. Grounded in media industries research, the method emphasizes the importance of close observation within the dynamic interface environments of VoD services. To this end, we present a set of reflections based on an exploratory study conducted on four US-based subscription VoD services in Spain and Belgium and propose three key sets of methodological considerations to be integrated in future assessments of prominence and discoverability tools and practices. First, a broader analysis of market characteristics and their interrelations is essential for conducting comparative research and understanding the strategies of transnational players within each market. Second, VoD services must be treated as individual cases shaped by specific industry practices and business models. Third, we recommend "getting personal" with the object of study through detailed analyses of interface architectures and consumption affordances, and propose the concept of a title's discovery arc to analyze its spatiotemporal placement. This approach underscores the value of contextual, qualitative insights to complement quantitative evaluations
Coping behaviors to reduce anxiety and depressive symptoms: A prospective repeated assessment study
Full text linkIntroduction: Health institutions provide general recommendations to cope with global crises such as pandemics or geopolitical tensions. However, these recommendations are mainly based on cross-sectional evidence. The preregistered Repeated Assessment of Behaviors and Symptoms in the Population (RABSYPO) study sought to establish prospective longitudinal evidence from a cohort with a demographic distribution similar to that of the Spanish population to provide evidence for developing solid universal recommendations to reduce anxiety and depressive symptoms during times of uncertainty.
Material and methods: We first recruited via social networks a pool of Spanish individuals willing to participate and then randomly selected some within each stratum of age × gender × region × urbanicity to conduct a one-year-long bi-weekly online follow-up about the frequency of ten simple potential coping behaviors as well as anxiety (GAD-7) and depressive symptoms (PHQ-9). Mixed-effects autoregressive moving average models were used to analyze the relationship between past behaviors" frequency and subsequent symptom changes across the twenty-seven time points.
Results: Among the 1049 who started the follow-up, 942 completed it and were included in the analyses. Avoiding excessive exposure to distressing news and maintaining a healthy/balanced diet, followed by spending time outdoors and physical exercise, were the coping behaviors most strongly associated with short and long-term reductions of anxiety and depressive symptoms. Engaging in relaxing activities and drinking water to hydrate were only associated with short-term symptom reductions. Socializing was associated with symptom reductions in the long term.
Conclusions: This study provides compelling prospective evidence that adopting a set of simple coping behaviors is associated with small but significant reductions in anxiety and depressive symptoms during times of uncertainty. It also includes a layman's summary of this evidence to help develop general recommendations that serve as universal tools for enhancing mental health and well-being.AXA Research Fund funded this project via an AXA Award granted to JR from the call for projects “Mitigating risk in the wake of the Covid-19 Pandemic”. LF thanks the support from an educational grant from the Instituto de Salud Carlos III (FI20/00047). CT and IG thanks the support from the Spanish Ministry of Science and Innovation (PI20/00344, PI23/00822), integrated into the Plan Nacional de I+D+I, and co-financed by ERDF Funds from the European Commission (“A Way of Making Europe”). JR thanks the support from Instituto de Salud Carlos III and the European Regional Development Fund (FEDER) (CPII19/00009) and the Secretaria d’Universitats i Recerca del Departament d’Economia i Coneixement (2021 SGR 1128)
Topic models for decision-support systems. Part I: Training, representation and exploitation of topic models
Full text linkAnalyzing document collections in Science, Technology, and Innovation (STI) is essential for informed policy-making. Advances in topic modeling offer powerful tools to uncover key themes within large, heterogeneous STI datasets that can inform decision-making. However, challenges such as aligning model outputs with expert knowledge, determining the desired topic granularity, and addressing model variability, limit their widespread adoption. This paper presents the Topic Analysis and Search Engine (tase), a platform developed within the European IntelComp project to address these limitations. tase combines Bayesian and Neural topic modeling techniques within a unified framework that incorporates an expert-in-the-loop approach for training and curating models. This framework is further enhanced with a Solr-based exploitation tool, featuring an innovative indexing method and a novel criterion for document retrieval. These features enable efficient semantic similarity calculations and seamless integration into decision-support systems. We demonstrate tase’s scalability and effectiveness through two real-world STI use cases, highlighting its potential for broader applications. The software is freely available as open-source under the MIT license.This project has received funding from the European Union’s Horizon 2020 research and innovation program under grant agreement No 101004870 (IntelComp project)