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Population dynamics in a Leslie-Gower predator-prey model with predator harvesting at high densities
No full textIn this paper, we propose a Leslie–Gower predator–prey model in which the predator can only be captured when its population size exceeds a critical value; the mean growth rate of the prey in the absence of the predator is subject to a semi-saturation rate that affects its birth curve, and the interaction between the two species is defined by a Holling II predation functional with alternative food for the predator. Since the proposed model is equivalent to a Filippov system, its mathematical analysis leads to a local study of the equilibria in each vector field corresponding to the proposed model, in addition to the study of the stability of its pseudo-equilibria located on the curve separating the two vector fields. In particular, the model could have between one and three pseudo-equilibria and at least one limit cycle surrounding one or two inner equilibria, locally unstable points.This research was supported by MCIN/AEI/10.13039/501100011033 through grant BADS, no. PID2019-109320GB-100, and the associated FPI contract PRE2019-088899 to Christian Cortés García. The Spanish MICINN has also funded the “Severo Ochoa” Centers of Excellence to CNB, SEV 2017-0712
Topic models for decision-support systems, Part II: Expert-in-the-loop hierarchical topic models
Full text linkTopic modeling has been extensively used across disciplines to extract knowledge from text collections for policy design, implementation, and monitoring. However, flat topic models are limited in their ability to group overly broad topics with more specific ones. Hierarchical topic models (htm) address this limitation by offering thematic analysis at different granularity levels, but existing htms rely on complex implementations, complicating hyperparameter tuning and domain expert-guided topic curation. This paper introduces two novel algorithms for hierarchical topic modeling: htm-ws (htm with word selection) and htm-ds (htm with document selection). These expert-in-the-loop methods enable domain experts to refine topic hierarchies by selecting subtopics for further partitioning. They are model-agnostic—compatible with both Bayesian and neural topic models—and require minimal hyperparameter tuning, comparable to flat topic models. Both algorithms are integrated within a tool for the training and exploitation of topic models, developed in the context of the IntelComp project. Experiments on three scientific paper datasets demonstrate the effectiveness of the algorithms through quantitative evaluations with automatic metrics and qualitative assessments via human judgment, including comparisons both between the two methods and against existing hierarchical topic models from the literature.This project has received funding from the European Union’s Horizon 2020 research and innovation program under grant agreement No 101004870 (IntelComp project)
Smart Agri-Region and Value Engineering
No full textAgriculture and silviculture offer interesting opportunities for food, energy, and construction sectors, but to transform such raw materials into valuable products, multiple engineering works must be carried out within R&D, innovation projects, and programs. The classical official decision to promote or supervise such projects involves many agents and criteria but rarely considers engineering quality, reusability, or other valuable and measurable attributes considered in ISO 25.000 or in value engineering guidelines. Missing them would increase technological, business, and programmatic risks, potentially wasting public money or credibility. Large projects are not free from these risks, and it is not a kind of madness to derive R&D and innovation funds to enable access to such valuable knowledge comprehensively, with models. In this context, communications and services, construction, and renewables play a crucial role in smart rural environments. Model-Based Systems Engineering (MBSE) and generative Artificial Intelligence (AI), combined with Natural Language Processing (NLP), are expected to help Knowledge Management (KM) in engineering and governance to supervise value engineering and their relationship with other metrics. Starting with a motivational and multidisciplinary framework for a smart rural transformation for System of Systems (SoS), the authors conduct specific bibliographic research on MBSE-NLP-AI use for automatizing systems engineering supervision at program governance levels
Hyperinvariant subspaces for trace class perturbations of normal operators and decomposability
No full textWe prove that a large class of trace-class perturbations of diagonalizable normal operators on a separable, infinite dimensional complex Hilbert space have non-trivial closed hyperinvariant subspaces. Moreover, a large subclass consists of decomposable operators in the sense of Colojoara and Foia
Collecting a large number of alters in egocentric network research: A comparative analysis of three approaches
No full textThis article presents an analysis of the impact of the number of alters elicited in an ego network on the structural properties of those networks. There continues to be debate about the pros and cons of eliciting a fixed number of alters for each respondent versus allowing the respondent to list as many or few alters as they would like. This article explores a random assignment of respondents to three treatment groups – (1) a fixed number of alters set at 30, (2) a variable number of alters up to 45, and (3) a variable number of alters up to 45 with a 20 alter minimum. The results indicate that, from a non-structural perspective, all levels of emotional proximity, interaction contexts, genders, and ages are consistently sampled across the three treatment groups. At the structural level, the behavior of individual metrics is also largely similar. However, the most significant differences arise in the collective behavior of structural metrics—specifically, in their correlation structure, the amount of redundant information each variable provides, and the diversity and interpretability of the observed structural variability. When a data collection strategy constrains network size, it reduces the sparsity of the correlation matrix, effectively decreasing the number of independent global variables needed to describe network structure and making these global variables less interpretable. In other words, networks constructed with a survey that limits size tend to be more similar to each other, exhibiting less structural diversity and yielding differences that are harder to interpret. However, we discuss how these differences may simply be mathematical artifacts, without necessarily implying a clear advantage in choosing one treatment over another. Finally, we argue that the field needs a targeted study to answer whether the differing numbers of alters listed is a function of network size.M.A.G.-C. acknowledges support from the Comunidad de Madrid, Spain through the grants for the hiring of pre-doctoral research personnel in training (reference PIPF-2023/COM-29487). M.A.G.-C. and A.S. acknowledge support from grant PID2022-141802NB-I00 (BASIC) funded by MCIN/AEI/10.13039/501100011033 and by ‘ERDFA way of making Europe’. M.A.G.-C., M.P.C, C.M, J.L.M. and A.S. acknowledge support from grant MapCDPerNets—Programa Fundamentos de la Fundación BBVA 2022
Instrucción del Vicerrector de Investigación y Transferencia sobre la filiación institucional del personal investigador de la Universidad Carlos III de Madrid
No full textEsta instrucción actualiza la Instrucción del Vicerrector de Investigación y Transferencia sobre la filiación institucional del personal investigador de la Universidad Carlos III de Madrid de 5 de noviembre de 2024, que a su vez, actualiza y amplía los criterios recogidos en el apartado 6.2 del Código de Buenas Prácticas de Investigación y Transferencia de la Universidad Carlos III de Madrid, aprobado por el Consejo de Gobierno en sesión de 14 de diciembre de 2017
The republican exile in France and Mexico: A comparative perspective
No full textEste estudio analiza comparativamente el exilio republicano español tras la Guerra Civil de 1939 en dos contextos clave: Francia y México. A partir de una mirada histórica, política y humana, se examina el modo en que ambos países acogieron a los exiliados, las condiciones de vida que enfrentaron, sus procesos de integración y los legados culturales y sociales que dejaron. Mientras que Francia representó un destino inmediato pero hostil, marcado por internamientos y un difícil proceso de asimilación, México ofreció desde el principio una recepción solidaria que facilitó la reconstrucción personal y profesional de los exiliados, propiciando una experiencia de transtierro más que de desarraigo. El trabajo subraya el papel decisivo del presidente Lázaro Cárdenas y del convenio con el Gobierno de Vichy, así como las tensiones internas del exilio en suelo francés, en contraste con la cohesión observada en México. Además, se abordan aspectos poco explorados, como el impacto generacional del exilio y la memoria histórica en ambos países receptores.This study offers a comparative analysis of the Spanish Republican exile following the 1939 Civil War, focusing on two key host countries: France and Mexico. From a historical, political, and human perspective, it examines how these nations received the exiles, the conditions they endured, their paths to integration, and the cultural and social legacies they left behind. While France represented an immediate but often hostile refuge marked by internment camps and a challenging assimilation process, Mexico provided a welcoming environment that enabled exiles to rebuild their lives, fostering a sense of transtierro (relocation without uprooting) rather than dislocation. The work highlights the decisive role of President Lázaro Cárdenas and the agreement with the Vichy government, as well as the internal political tensions among exiles in France—contrasting with the solidarity and cohesion observed in Mexico. Additionally, the article explores lesser-known aspects such as the generational impact of exile and the differing ways historical memory has been preserved in both host countries
Generalized dynamic transient model for MTDC networks covering multiple topologies and contingencies
No full textThis paper proposes a versatile and modular Multi-Terminal High Voltage Direct Current (MTDC) network model with a compact matrix formulation. There will be a growing deployment of MTDC grids, necessitating the development of novel tools and models for their analysis and simulation. The first contribution of the paper is the proposal of a new MTDC network model using graph theory. The model preserves the dynamics of the grid and is flexible to adapt to different topologies and sizes. The second contribution is the implementation of the proposed MTDC model in an integrated software framework for the dynamic simulation, which incorporates an automatic flat-start initialization from an AC/DC power flow. The tool is developed in Matlab/Simulink and it includes the possibility to simulate various types of contingencies including different types of short-circuits, line clearances and converter outages, both for monopolar and bipolar DC networks. This tool is designed for time domain simulation and small-signal analysis of systems, including MTDC networks, with the objective of studying the dynamics of novel converter models and control strategies. The results demonstrate the functionalities of the proposed MTDC network model and simulation tool, highlighting the importance of network dynamics in simulations with power electronic converters.This work was supported by the Spanish Research Agency under Grant TED2021-130468B-I00 MCIN/AEI/MCIN/AEI/10.13039/ 501100011033. NextGenerationEU/PRTR: CONTRIBUTION OF GRID FORMING CONVERTERS TO POWER SYSTEMS STABILITY AND OPERABILITY WITH HIGH PENETRATION OF RENEWABLE ENERGY SOURCES (GFM-RES)
Embodied Ideation, Toolkits, and Sketching
No full textMovement-based design foregrounds the moving and sentient body, fostering holistic engagement with the surrounding physical, material, and sociospatial contexts. Over the years, this approach has yielded multiple methodologies, tools, and exemplars to support body-based ideation. In this studio, we explore tools that facilitate embodied thinking and the creative processes of designing with, through, and for the body. In particular, we focus on: i) embodied ideation tools, kits, and technology probes to prompt ideation; ii) sketching and other documentation techniques to materialize ephemeral embodied action during ideation. We will bring tools and techniques to engage with both aspects, and we will invite participants to bring their own, which can be physical or technological, low or high-fidelity. This hands-on studio will provide a space to collectively engage in embodied ideation and sketching; exploring, analysing, and engaging deeply with the available objects and methods. The studio will culminate in a rich set of visual material and an annotated portfolio, which will be shared with the broader community, fostering connections among designers interested in movement-based and tangible design.This work has been partially supported by the Madrid Government (Comunidad de Madrid, Spain) under the Multiannual Agreement with Universidad Carlos III de Madrid in the line of “Research Funds for Beatriz Galindo Fellowships” (MOVINTPLAYLAB-CM-UC3M 2021/00050/001) and in the context of the V PRICIT (Regional Programme of Research and Technological Innovation), the European Research Council under the European Union Horizon 2020 research and innovation programme (grant agreement number 101002711; project BODYinTRANSIT), and the Spanish Agencia Estatal de Investigación (PID2019-105579RB-I00/AEI/10.13039/501100011033 and Programa I3)
Power Over Fiber Co-Transmission With 39.5 Gpbs Mixing 5G NR Analog Radio Over Fiber and NRZ Signals
No full textIn this work, we demonstrate the first time simultaneous transmission of Power over Fiber, 5G New Radio and digital signals in a single optical fiber link. We transmit eight 256 QAM 5G NR and two GPON-compliant digital No Return to Zero signals through 4 cores of a 250 m 7-core Multicore Fiber, while two Power over Fiber signals of a total 3463.2 mW are launched through other two cores. An electrical power delivery of 688.8 mW is achieved, while a total data rate of 39.5 Gbps is obtained for the 5G NR and the digital communications signals, setting a new record in simultaneous PoF and data links in Multicore Fibers.This work was supported in part by UNICO-5G I+D Ministerio de Asuntos Económicos y Transformación Digital and NextGenerationEU under Grant TSI-063000-2021-135 (6G Xtreme I) and in part by Spanish Research Agency under Grant PID2021-122505OB-C32