Artículos (Matemática Aplicada I)

URI permanente para esta colecciónhttps://hdl.handle.net/11441/10894

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Simulating 241Pu, 241Am and 237Np transport released from a nuclear fuel reprocessing plant in the European Shelf Seas and their fluxes into the Arctic
(Elsevier, 2026-06) Cortés Parejo, María del Carmen; Periáñez Rodríguez, Raúl; Matemática Aplicada I; Física Aplicada I; FQM164: Matemática Discreta: Teoría de Grafos y Geometría Computacional; RNM138: Física Nuclear Aplicada
A three-dimensional Lagrangian particle-tracking model has been applied to simulate the dispersion, sediment interactions and radioactive decay of 241Pu, 241Am and 237Np released from the Sellafield nuclear fuel reprocessing plant into the European Shelf Seas over the period 1952–2014. The model incorporates advection by currents, turbulent diffusion, reversible sediment-water exchanges and the explicit representation of the 241Pu→ 241Am→ 237Np decay chain. Simulated concentrations in surface waters and bottom sediments are compared with available measurements in the Irish Sea, North Sea and adjacent regions, reproducing the contrasting environmental behaviours of the three radionuclides. Results highlight the strong sediment retention of 241Am and 241Pu, whereas 237Np exhibits a more conservative behaviour and wider dispersal. Fluxes into the Arctic Ocean through the Norwegian Coastal Current are quantified, yielding cumulative exports of 2.07 × 1014 Bq for 241Pu and 1.43 × 1014 Bq for 237Np, and suggesting an average transit time of approximately 10 years for 241Pu from Sellafield to the Arctic boundary. Basin-scale inventories in water and sediments are also estimated, revealing the dominant role of sediments as long-term sinks for particlereactive radionuclides. The results demonstrate the capability of the modelling framework to provide internally consistent multi-decadal inventories and fluxes for complex radioactive decay chains in shelf-sea environments.
Finite element approximation and very weak solution existence in a two-dimensional, degenerate Keller-Segel model
(Springer, 2026) Gutiérrez Santacreu, Juan Vicente; Matemática Aplicada I; Universidad de Sevilla; FQM131: Ecuaciones diferenciales, Simulación Num. y Desarrollo Software
This paper is devoted to the design and analysis of a numerical algorithm for approximating solutions of a degenerate cross-diffusion system, which models particular instances of taxis-type migration processes under local sensing mechanisms. The degeneracy leads to solutions that are very weak due to the low regularity themselves. Specifically, the solutions satisfy pointwise bounds (such as positivity and the maximum principle), integrability (such as mass conservation), and dual a priori estimates. The proposed numerical scheme combines a finite element spatial discretization with Euler time stepping. The discrete solutions preserve the above-mentioned properties at the discrete level, enabling the derivation of compactness arguments and the convergence (up to a subsequence) of the numerical solutions to a very weak solution of the continuous problem on two-dimensional polygonal domains.
Complexity and exact values for [𝑘]-Roman and strong Roman domination for specific graph families
(MDPI, 2026-05-01) Valenzuela Tripodoro, Juan Carlos; Mateos Camacho, María Antonia; Cera López, Martín; Álvarez Ruiz, María del Pilar; Matemática Aplicada I; Ministerio de Ciencia, Innovación y Universidades (MICIU). España; Junta de Andalucía; FQM240: Invariantes en Teoría de Grafos y Optimización
Motivated by the original idea of defending the Roman Empire, all these domination concepts can be interpreted as vertex-labeling schemes that model the allocation of resources to protect a graph against attacks. A Roman dominating function (RDF) is a labeling of the vertices of a graph with labels in {0,1,2} such that every vertex labeled 0 is adjacent to at least one vertex labeled 2. The weight of an RDF is the sum of all vertex labels. Vertices labeled 2 are intended to protect their neighbors labeled 0. The Roman domination number is the minimum weight of an RDF on the graph. In 2017, Álvarez et al. introduced strong Roman domination as a variant of Roman domination designed to protect the vertices of a graph against multiple simultaneous attacks. In 2021, Ahangar et al. defined [𝑘] -Roman domination, another model intended to defend a graph against individual attacks on vertices. In this paper, we investigate the computational complexity of the associated decision problems for [𝑘] -Roman domination and strong Roman domination. Furthermore, we determine exact values of these parameters for several graph families under both variants.
The assembly and dynamics of ecological communities in an ever-changing world
(Ecological Society of America, 2024-07-18) Godoy, Oscar; Soler Toscano, Fernando; Portillo Fernández, José Ramón; Langa Rosado, José Antonio; Ecuaciones Diferenciales y Análisis Numérico; FQM314: Análisis Estocástico de Sistemas Diferenciales
Alternative perspectives on the maintenance of biodiversity and the assembly of ecological communities suggest that both processes cannot be investigated simultaneously. In this concept and synthesis, we challenge this view by presenting major theoretical advances in structural stability and permanence theory. These advances, which provide complementary views, allow studying the short- and long-term dynamics of ecological communities as changes in species richness, composition, and abundance. Here, the global attractor, technically named informational structure (IS), is the central element to construct from information of species’ intrinsic growth rates and their strength and sign of interactions. The global attractor has four main properties: (1) It contains all the limits of what is feasible and unfeasible of the dynamical behavior of an ecological system, therefore, (2) it provides a thorough characterization of all combinations of species’ richness and composition in which species can coexist (i.e., feasible and stable equilibrium), (3) as well as all connections (paths) of assembly between coexisting communities. Importantly, (4) such topology of coexisting communities and their connections changes when environmental (abiotic and biotic) variation affects the ability of species to grow and interact with others. Overall, these four properties allow switching from a traditional evaluation of species coexistence at equilibrium to a much more realistic nonequilibrium perspective where changes in the structure of the global attractor underlie the transient ecological dynamics. Several fields in ecology can benefit from the study of an IS. For instance, it can serve to evaluate community responses after the end of a perturbation, to design restoration trajectories, to study the consequences of biological invasions on the persistence of native species within communities, or to assess ecosystem health status. We illustrate this latter possibility with empirical observations of 7 years in Mediterranean annual grasslands. We document that extremely wet or dry years generate ISs supporting few coexisting communities and few assembly paths. The remaining communities distinguish winners from losers of ongoing climate change and indicate the limits to future community assembly opportunities. A fully tractable operational framework is readily available to understand and predict the assembly and dynamics of ecological communities in an ever-changing world.
Cooperation maximizes biodiversity
(bioRxiv, 2024-10-25) Godoy, Óscar; Soler Toscano, Fernando; Portillo Fernández, José Ramón; Suárez Fernández, Antonio; Langa Rosado, José Antonio; Ecuaciones Diferenciales y Análisis Numérico; FQM131: Ecuaciones diferenciales, Simulación Num. y Desarrollo Software
Cooperation, the mutual benefit that individuals of different species obtain when they interact together, is ubiquitous in nature. Despite their importance, most of all current ecological theories have been formalized focusing on negative interactions such as competition or predation. The role of cooperation, or other types of positive interactions including facilitation and mutualism, has not been fully addressed, or, if so, always in combination with negative interactions. This fact limits our understanding of the unique features by which cooperation as opposed to competition promotes biodiversity. To address this gap, we introduce here cooperation into structural stability, a general framework to understand how species interactions and environmental variability determine the long-term persistence of species within communities. Compared to a pure competitive case, cooperation promotes three distinctive features. First, cooperation increases the opportunities for species to coexist. This feature increases the persistence of species with contrasted phylogenetic, functional, and demographic strategies that the environment would otherwise filter. Second, cooperation creates intertwined biodiversity where the existence of some species begets the presence of others. Third, cooperation promotes multistability by changing the dynamics of community assembly due to variations in environmental conditions. In conclusion, we present a fully operational framework to understand the unique ecological roles of cooperation in nature. It indicates that cooperation as opposed to competition maximizes the maintenance of biodiversity.
Roman domination in weighted graphs
(MDPI, 2026-01-29) Cera López, Martín; García Vázquez, Pedro; Valenzuela Tripodoro, Juan Carlos; Matemática Aplicada I; Ministerio de Ciencia, Innovación y Universidades (MICIU). España; European Commission (EC); Junta de Andalucía; FQM240: Invariantes en Teoría de Grafos y Optimización
A Roman dominating function for a (non-weighted) graph G = (V, E) is a function f : V → {0, 1, 2} such that every vertex u ∈ V with f(u) = 0 has at least one neighbor v ∈ V such that f(v) = 2. The minimum weight ∑v∈V f(v) of a Roman dominating function f on G is called the Roman domination number of G and is denoted by γR(G). A graph G = (V, E), together with a positive real-valued weight-function w : V → R>0, is called a weighted graph and is denoted by (G; w). The minimum weight ∑v∈V f(v)w(v) of a Roman dominating function f on G is called the weighted Roman domination number of G and is denoted by γwR(G). The domination and Roman domination numbers of unweighted graphs have been extensively studied, particularly for their applications in bioinformatics and computational biology. However, graphs used to model biomolecular structures often require weights to be biologically meaningful. In this paper, we initiate the study of the weighted Roman domination number in weighted graphs. We first establish several bounds for this parameter and present various realizability results. Furthermore, we determine the exact values for several well-known graph families and demonstrate an equivalence between the weighted Roman domination number and the differential of a weighted graph.
A general framework for invasion cycles in ecology
(Wiley , 2026) Calleja-Solanas, Violeta; Moura, Rafael O.; Langa Rosado, José Antonio; Portillo Fernández, José Ramón; Soler Toscano, Fernando; Godoy, Óscar; Ecuaciones Diferenciales y Análisis Numérico; Matemática Aplicada I; Filosofía y Lógica y Filosofía de la Ciencia; Ministerio de Ciencia e Innovación (MICIN). España; IMUS-María de Maeztu; São Paulo Research Foundation (FAPESP); Ministerio de Ciencia, Innovación y Universidades (MICIU). España; European Commission. Fondo Social Europeo (FSO)
Theory predicts that indirect interactions in ecological networks sustain species diversity through oscillatory dynamics. However, a framework linking interaction structure to the presence, type, and complexity of these cycles is lacking. Here, we develop an analytical toolbox combining invasion graphs with a mathematical decomposition of interaction matrices into symmetric and antisymmetric components. We find that invasion cycles—closed loops of species invasions—are suppressed when symmetric interactions dominate, reflecting strong self-limitation. Conversely, antisymmetric dominance, indicating competitive asymmetries, leads to the well-known cycles of single-species invasion such as rock-paper-scissors as well as novel multispecies invasion patterns, in which several species simultaneously invade each transition of the cycle. As asymmetries increase, more complex cycles involving both sequential and simultaneous invasions emerge. Yet this potential for cycles is suppressed as variability in intrinsic growth rates increases. Our work clarifies when interactions drive cycles and introduces a simple ratio that assesses symmetric versus antisymmetric contributions in the interaction matrix, constraining cycle emergence and the number of species they can sustain.
The role of shot velocity in advanced post-shot metrics: evidence from the UEFA European Football Championships
(MDPI, 2026-02-13) Cruz Torres, Blanca de la; Ruiz de Alarcón Quintero, Anselmo; Navarro Castro, Miguel; Fisioterapia; Matemática Aplicada I
Ball velocity is a critical determinant of shot effectiveness in football, yet its influence on advanced post-shot metrics, such as expected shot impact timing (xSIT) and expected goals on target (xGOT), remains poorly understood, particularly in the context of sex-specific differences. This study examined the relationship between ball velocity and these metrics in men’s and women’s elite European tournaments. Methods: A total of 2174 shots were analyzed from all matches of the 2024 UEFA Men’s EURO (n = 1305) and 2025 UEFA Women’s EURO (n = 869), classified as goal shots on target, non-goal shots on target, and shots off target. Ball velocity was measured for each shot, and its associations with xSIT, our own xGOT model and the StatsBomb xGOT model were quantified using correlation coefficients. Results: Ball velocity differed significantly between sexes (p < 0.001), with higher values in men, and goal shots on target exhibited lower velocities than non-goal or off-target shots, indicating a speed–accuracy trade-off. Only xSIT and our own xGOT model were sensitive to ball velocity, reflecting sex-specific differences (p < 0.001). When comparing shot types across advanced metrics, a consistent trend was observed in both tournaments: xSIT showed no significant differences between goal and non-goal shots, whereas both xGOT models were higher for goal shots on target. Correlations indicated a moderate positive relationship between xSIT and ball velocity, and moderate negative correlations for both xGOT models, slightly stronger in men. Conclusions: Ball velocity is a critical factor influencing shot performance and advanced post-shot metrics, with notable sex-specific differences.
Incorporating radioactive decay chains within Lagrangian marine radionuclide transport models for assessing the consequences of nuclear accidents
(MDPI, 2026-02-08) Cortés Parejo, María del Carmen; Periáñez Rodríguez, Raúl; Matemática Aplicada I; Física Aplicada I; FQM164: Matemática Discreta: Teoría de Grafos y Geometría Computacional; RNM138: Física Nuclear Aplicada
Lagrangian particle-tracking models are increasingly used to simulate radionuclide transport in marine environments, especially for assessing the consequences of accidental releases. However, existing models generally neglect radioactive decay chains, limiting their ability to reproduce the complete behavior of radionuclides and their progeny. To the authors’ knowledge, this work presents the first implementation of radioactive decay chains within a fully three-dimensional Lagrangian marine radionuclide transport model, explicitly coupling stochastic particle tracking with decay kinetics and dynamic sediment–water interactions, enabling a realistic simulation of parent–daughter transformations in the ocean. The approach is tested for the chain in the Western Mediterranean Sea, following a hypothetical nuclear accident. Results confirm that the stochastic treatment accurately reproduces analytical decay solutions and can be seamlessly incorporated into operational-scale transport simulations. The framework can be extended to other radionuclide series and marine domains, providing a versatile and computationally efficient tool for emergency response, environmental impact assessment, and safety analysis in nuclear engineering applications.
Modelling the accumulation of 137Cs by Atlantic bluefin tuna (Thunnus thynnus) after a hypothetical nuclear accident in the Northwest Atlantic Ocean
(Elsevier, 2026-01) Cortés Parejo, María del Carmen; Periáñez Rodríguez, Raúl; Block, Barbara A.; Castleton, Michael R.; Cermeño Villanueva, Pablo; Dedman, Simon; Matemática Aplicada I; Física Aplicada I; FQM164: Matemática Discreta: Teoría de Grafos y Geometría Computacional; RNM138: Física Nuclear Aplicada
The potential accumulation of radionuclides in migratory fish following nuclear accidents is a concern for marine ecology and human consumption. We developed and applied a Lagrangian numerical model coupled with a four-level food web uptake module to simulate the transport and bioaccumulation of 137Cs in Atlantic bluefin tuna (Thunnus thynnus) in the Northwest Atlantic Ocean, following hypothetical Fukushima-like releases from three coastal nuclear power plants in eastern North America. Tuna trajectories were obtained from electronic tagging data, and 137Cs transfers from water and prey were modelled daily at each tuna location. Simulations show that even when tuna pass through contaminated water and food patches, the resulting 137Cs concentrations in their flesh remain low, with maximum values around 1 Bq/kg wet weight. These concentrations are well below international safety limits and often below typical background levels. The study confirms that the rapid movement of migratory species limits radionuclide uptake, suggesting that tuna consumption would remain safe even in the event of such accidents.
Quantifying Football Shooting Precision: The Expected Shot Impact Timing (xSIT) Approach
(MDPI AG, 2025) Cruz Torres, Blanca de la; Navarro Castro, Miguel; Ruíz de Alarcón Quintero, Anselmo; Matemática Aplicada I; Comité de Ética de la Universidad de Sevilla
Current advanced metrics do not sufficiently isolate and quantify the quality of the shooter’s technical execution under match conditions. Objective: This study aimed to develop an Expected Shot Impact Timing (xSIT) model to evaluate the shooting action by considering the spatial configuration of the shooter, the goalkeeper (GK), and all outfield players, as well as incorporating dynamic variables such as ball velocity and player reaction time. Additionally, this study sought to compare the performance and discriminative capacity of two existing post-shot expected goal metrics (xSIT and xGOT, expected goals on target) in evaluating the probability of scoring for shots on target after the moment of execution. Methods: Formal definitions were established for the following: (i) the ball shot location, (ii) the ball velocity, (iii) the GK location, and (iv) the outfield player’s location. An xSIT model incorporating geometric parameters was designed to optimize performance based on ball position and players’ position. The model was tested using all shots from the 2023 Women’s World Cup and the 2022 Men’s World Cup. A 5-fold cross-validation procedure was applied to evaluate the x SIT model’s performance, and an independent Student’s t-test was performed to statistically compare the performance of the xSIT and xGOT models. Results: The k-fold cross-validation yielded an AUC-ROC score of 0.92 and 84% accuracy, confirming the model’s ability to differentiate successful shooter performance. Statistically and clinically significant differences were observed between the xSIT and xGOT metrics across all analyzed variables, including total shots on target, goal shots, and saved shots (p < 0.001 in all cases). Conclusions: The xSIT metric offers a more nuanced and context-sensitive assessment of shot execution by the shooter, representing a significant advancement over existing post-shot evaluation models. Significant differences were observed between men’s and women’s tournaments.
Stability of parametrically driven, damped nonlinear Dirac solitons
(American Institute of Physics, 2025-08-22) Sánchez-Rey, Bernardo; Mellado-Alcedo, David; Quintero, Niurka R.; Física Aplicada I; Matemática Aplicada I; Junta de Andalucía; Ministerio de Ciencia e Innovación (MICIN). España; Universidad de Sevilla; FQM392: Física Interdisciplinar y de no Equilibrio; FQM415: Modelado Físico-Matemático de Sistemas no Lineales
The linear stability of two exact stationary solutions of the parametrically driven, damped nonlinear Dirac equation is investigated. Stability is ascertained through the resolution of the eigenvalue problem, which stems from the linearization of this equation around the exact solutions. On the one hand, it is proven that one of these solutions is always unstable, which confirms previous analysis based on a variational method. On the other hand, it is shown that sufficiently large dissipation guarantees the stability of the second solution. Specifically, we determine the stability curve that separates stable and unstable regions in the parameter space. The dependence of the stability diagram on the driven frequency is also studied, and it is shown that low-frequency solitons are stable across the entire parameter space. These results have been corroborated with extensive simulations of the parametrically driven and damped nonlinear Dirac equation by employing a novel and recently proposed numerical algorithm that minimizes discretization errors. The nonlinear Dirac equation has attracted a lot of attention in recent years. Far from being restricted to the realm of high-energy particle physics, it also describes nonlinear excitations in other fields, such as nonlinear optics and Bose-Einstein condensates. Since these kinds of systems are susceptible to being controlled and manipulated, they constitute an excellent benchmark to study relativistic solitons. Moreover, dissipative losses, present in all physical systems, cause a decay of the soliton amplitude. Therefore, an interesting question is whether a parametric force can inject energy from outside to compensate for the losses in such a way that the soliton becomes stable. In this paper, this question is answered affirmatively. In fact, we prove that one exact stationary soliton solution of the parametrically driven and damped nonlinear Dirac equation is linearly stable in the majority of the parameter space. Furthermore, it is shown that instability regions tend to disappear for sufficiently low frequencies.
Expected Shot impact Timing (xSIT) and other advanced metrics as indicators of performance in English men’s and women’s professional football
(MDPI, 2025-10-02) Cruz Torres, Blanca de la; Navarro Castro, Miguel; Ruiz de Alarcón Quintero, Anselmo; Fisioterapia; Matemática Aplicada I
Blackground: Football performance analysis has grown rapidly in recent years, with increasing interest in advanced metrics to more accurately evaluate both individual and team performance. The aim of this study was to examine the utility of the Expected Shots Impact Timing (xSIT) metric as an indicator of shooting performance in English professional football, specifically in the men’s Premier League (PL) and the Women’s Super League (WSL). Methods: A total of 9831 shots from the PL (2015/16 season) and 3219 shots from the WSL (2020/21 season) were analyzed. Data were obtained from publicly accessible football databases. The variables examined included goals, Possession Value (PV), Expected Goals (xG), Expected Goals on Target (xGOT), and xSIT. All variables were normalized per match (90 min). Descriptive statistics, correlational analyses, and comparative analyses between leagues. Results: The WSL exhibited a significantly higher PV than the PL (p < 0.001), whereas the remaining metrics showed no significant differences between leagues (p > 0.05). Moreover, in the WSL, all performance indicators displayed very strong correlations with goals, while in the PL, similarly strong associations were observed, except for PV, which showed only a weak relationship. Conclusions: the xSIT metric, as an indicator of shooting performance, may be regarded as an influential factor in determining match outcomes across both leagues.
Well-balanced physics-based finite volume schemes for Saint-Venant–Exner-type models of sediment transport
(Elsevier, 2025) Bürguer, Raimund; Fernández Nieto, Enrique Domingo; Garres-Díaz, José; Moya Abuhadba, Jorge Johnny; Matemática Aplicada I; Matemática Aplicada II; Junta de Andalucía; European Union (UE)
The Saint-Venant–Exner (SVE) model is widely used for the description of sediment transport including bedload, erosion, and deposition processes. A modified version of the SVE model, which includes sediment concentration, incorporates exchange of sediment between the fluid and an erodible bed and a non-hydrostatic pressure for the fluid along with non-equilibrium entrainment and deposition velocities, is introduced. Gravitational effects on erosion are described by an effective shear stress formulation. This modified SVE model is derived from a general approach with density variations. It preserves the mass of both the sediment and the fluid, and satisfies a dissipative energy balance. On the other hand, well-balanced finite volume schemes adapted for SVE models are derived since standard well-balanced schemes for the Saint-Venant system with fixed bottom are in general no more well-balanced when applied to the SVE model. The latter property is due to the uncontrolled numerical diffusion associated with the bed evolution equation. Two novel techniques to achieve the well-balanced property for the modified SVE model are proposed. The first is a new polynomial-viscosity-matrix-based (PVM) scheme, denoted “PVM-2I”, that modifies the numerical approximation of the bed evolution equation according to its related characteristic speed. The second is a physically motivated correction of the numerical diffusion term for the Rusanov and Harten–Lax–van Leer (HLL) schemes. The proposed schemes are positivity-preserving for the water height. Numerical solutions are compared with exact solutions with gravitational effects, with a novel exact solution in non-equilibrium conditions, and with experimental data. It is illustrated how the use of standard non-well-balanced schemes leads to a large artificial (unphysical) erosion and completely degraded solutions. This undesirable behaviour is avoided by the proposed well-balanced schemes. Moreover, it is demonstrated that for dam-break flows the inclusion of non-hydrostatic pressure improves the prediction of the water surface and sediment evolution, while for overtopping flow erosion tests, accounting for erosion–deposition exchanges between the bedload and suspended sediment layers leads to better agreement with experimental data.
A Third-Order Finite Volume Semi-Implicit Method for the Shallow Water-Exner Model
(Springer, 2025) Fernández Nieto, Enrique Domingo; Garres-Díaz, José; Macca, Emanuele; Russo, Giovanni; Matemática Aplicada I; Matemática Aplicada II; Junta de Andalucía; European Union; Ministerio de Ciencia e Innovación (MICIN). España
In this work, third-order semi-implicit schemes on staggered meshes for the shallow water and Saint-Venant-Exner systems are presented. They are based on a third-order extension of the technique introduced in Casulli & Cheng [15]. The stability conditions for these schemes depend on the velocity and not on the celerity, allowing us to reduce computational efforts, especially in subcritical flow simulations, which is the regime we are mainly interested in. The main novelty consists in the third-order approximation of the pressure gradient term in the momentum equation through appropriate polynomial reconstructions. Concretely, CWENO conservative reconstruction is considered for the water thickness h and a centered fourth-degree polynomial is adopted interpolating the cell averages of the free surface n. For time discretization, a third-order IMEX scheme is applied. In addition, a novel time-dependent semi-analytical solution for Saint-Venant-Exner system is introduced and compared with the numerical ones. Several tests are performed, including accuracy tests showing third-order accuracy, well-balance tests, and simulations of slow bedload processes for large time.
Analysis of Shots Trajectory and Effectiveness in Women’s and Men’s Football European Championship Matches
(MDPI, 2025-06-12) Cruz Torres, Blanca de la; Navarro Castro, Miguel; Ruiz-de-Alarcón-Quintero, Anselmo; Matemática Aplicada I; Fisioterapia
Shots on target are a crucial factor in football performance, yet the impact of categorizing shots as low or ground-level and high or parabolic has not been fully explored. The objective of this study was to analyze whether there are differences in the frequency and effectiveness (as measured by xGOT) between parabolic and low shots on target in international men’s and women’s football competitions. The results revealed that the most common shot type was the parabolic shot, occurring in 59.86% of shots on goal in the men’s competition (270 shots) and 67.12% in the women’s competition (196 shots). In the overall set of shots, 62.77% were parabolic (466 shots). No significant differences were observed between the competitions (p > 0.05). Regarding the xGOT values, no significant differences were observed for any of the interaction effects analyzed (gender, shot type and shot outcome). The conclusion was that the parabolic shot was the most frequent type of shot on target in both men’s and women’s football.
Latin bitrades derived from quasigroup autoparatopisms
(Springer, 2025) Cavenagh, Nicholas J.; Falcón Ganfornina, Raúl Manuel; Matemática Aplicada I; Universidad de Sevilla
In 2008, Cavenagh, Drápal and Hämäläinen described a method of constructing Latin trades using groups. The Latin trades that arise from this construction are entry-transitive (that is, there always exists an autoparatopism of the Latin trade mapping any ordered triple to any other ordered triple). Moreover, useful properties of the Latin trade can be established using properties of the group. However, the construction does not give a direct embedding of the Latin trade into any particular Latin square. In this paper , we propose a similar approach to the above to construct Latin trades embedded in a Latin square L, via the autoparatopism group of the quasigroup with Cayley table L. We apply this theory to identify non-trivial entry-transitive trades in some group operation tables as well as in Latin squares that arise from quadratic orthomorphisms. Explore related subjects
Physics-based stabilized finite element approximations of the Poisson–Nernst–Planck equations
(Elsevier Science, 2025) Bonilla, Jesús; Gutiérrez Santacreu, Juan Vicente; Matemática Aplicada I; Ministerio de Ciencia e Innovación (MICIN). España; Consejería de Economía, Conocimiento, Empresas y Universidad
We present and analyze two stabilized finite element methods for solving numerically the Poisson–Nernst–Planck equations. The stabilization we consider is carried out by using a shock detector and a discrete graph Laplacian operator for the ion equations, whereas the discrete equation for the electric potential need not be stabilized. Discrete solutions stemmed from the first algorithm preserve both maximum and minimum discrete principles. For the second algorithm, its discrete solutions are conceived so that they hold discrete principles and obey an entropy law provided that an acuteness condition is imposed for meshes. Remarkably the latter is found to be unconditionally stable. We validate our methodology through transient numerical experiments that show convergence toward steady-state solutions.
Partial functions induced by morphisms between of persistence modules
(Universitat Jaume I, 2023) González Díaz, Rocío; Soriano Trigueros, Manuel; Torras Casas, Álvaro; Matemática Aplicada I; Agencia Estatal de Investigación. España; Agencia Andaluza del Conocimiento
Persistence modules are fundamental algebraic structures in topological data analysis. One often needs to understand morphisms between a pair of persistence modules as these appear very naturally in practical situations. Even though one might express such morphisms as the direct sum of indecomposable modules, in most cases the decomposition is out of our reach. We define an easy-to-compute partial function relating the interval decomposition of the domain and codomain of such morphisms. This approach gives information about the inner structure of the morphism in a computable way, allowing their use in topological data analysis.
Well-balanced POD-based reduced-order models for finite volume approximation of hyperbolic balance laws
(Elsevier Science , 2025-05-04) Gómez Bueno, Irene; Fernández Nieto, Enrique Domingo; Rubino, Samuele; Matemática Aplicada I; Ministerio de Ciencia e Innovación (MICIN). España
This paper introduces a reduced-order modeling approach based on finite volume methods for hyperbolic systems, combining Proper Orthogonal Decomposition (POD) with the Discrete Empirical Interpolation Method (DEIM) and Proper Interval Decomposition (PID). Applied to systems such as the transport equation with source term, non-homogeneous Burgers equation, and shallow water equations with non-flat bathymetry and Manning friction, this method achieves significant improvements in computational efficiency and accuracy compared to previous time averaging techniques. A theoretical result justifying the use of well-balanced FullOrder Models (FOMs) is presented. Numerical experiments validate the approach, demonstrating its accuracy and efficiency. Furthermore, the question of prediction of solutions for systems that depend on some physical parameters is also addressed, and a sensitivity analysis on POD parameters confirms the model’s robustness and efficiency in this case.

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