Now showing items 361-380 of 719

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    The Santaló point for the Holmes-Thompson boundary area 

    Balacheff, F.; Solanes, G.; Tzanev, K. (Publication date: 2022-03-05)

    We explore the notion of Santaló point for the Holmes-Thompson boundary area of a convex body in a normed space. In the case where the norm is C1, and in the case where unit ball and convex body coincide, we prove existence ...

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    Percolation on Random Graphs with a Fixed Degree Sequence 

    Fountoulakis, N.; Joos, F.; Perarnau, G. (Publication date: 2022-01-11)

    We consider bond percolation on random graphs with given degrees and bounded average degree. In particular, we consider the order of the largest component after the random deletion of the edges of such a random graph. We ...

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    On the cyclicity of Kolmogorov polycycles 

    Marín, D.; Villadelprat, J. (Publication date: 2022-07-30)

    In this paper we study planar polynomial Kolmogorov’s differential systems Xµ {ẋ = x f (x, y; µ), ẏ = yg(x, y; µ), with the parameter µ varying in an open subset Λ ⊂ RN. Compactifying Xµ to the Poincaré disc, the boundary ...

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    The local cyclicity problem: Melnikov method using Lyapunov constants 

    Gouveia, L.F.S.; Torregrosa, J. (Publication date: 2022-04-19)

    In 1991, Chicone and Jacobs showed the equivalence between the computation of the firstorder Taylor developments of the Lyapunov constants and the developments of the first Melnikov function near a non-degenerate monodromic ...

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    Environmental heterogeneity in human health studies. A compositional methodology for Land Use and Land cover data 

    Zaldo-Aubanell, Q.; Serra, I.; Bach, A.; Knobel, P.; López, F.C.; Belmonte, J.; Daunis-i-Estadella, P.; Maneja, R. (Publication date: 2021-09-21)

    The use of Land use and Land cover (LULC) data is gradually becoming more widely spread in studies relating the environment to human health. However, little research has acknowledged the compositional nature of these data. ...

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    Magnetic nanodrug delivery in non-Newtonian blood flows 

    Fanelli, C.; Kaouri, K.; Phillips, T.N.; Myers, T.G.; Font, F. (Publication date: 2022-09-04)

    With the goal of determining strategies to maximise drug delivery to a specific site in the body, we developed a mathematical model for the transport of drug nanocarriers (nanoparticles) in the bloodstream under the influence ...

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    Microfluidics Approach to the Mechanical Properties of Red Blood Cell Membrane and Their Effect on Blood Rheology 

    Trejo-Soto, C.; Lázaro, G.R.; Pagonabarraga, I.; Hernández-Machado, A. (Publication date: 2022-02-13)

    In this article, we describe the general features of red blood cell membranes and their effect on blood flow and blood rheology. We first present a basic description of membranes and move forward to red blood cell membranes’ ...

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    Convex analysis on polyhedral spaces 

    Botero, A.M.; Ignacio Burgos Gil, J.; Sombra, M. (Publication date: 2022-01-24)

    We introduce notions of concavity for functions on balanced polyhedral spaces, and we show that concave functions on such spaces satisfy several strong continuity properties. © 2022, The Author(s).

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    Slope inequalities for fibrations of non-maximal Albanese dimension 

    Barja, M.Á. (Publication date: 2021-06-15)

    We study and obtain Slope inequalities for fibred irregular varieties of non-maximal Albanese dimension. We give a comparison theorem between Clifford–Severi and Slope inequalities for this type of fibrations. We also ...

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    Normal limiting distributions for systems of linear equations in random sets 

    Rué, J.; Wötzel, M. (Publication date: 2022-09-15)

    We consider the binomial random set model [n]p where each element in {1,…,n} is chosen independently with probability p:=p(n). We show that for essentially all regimes of p and very general conditions for a matrix A and a ...

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    On a local-global principle for quadratic twists of abelian varieties 

    Fité, F. (Publication date: 2022-12-06)

    Let A and A′ be abelian varieties defined over a number field k of dimension g≥ 1. For g≤ 3 , we show that the following local-global principle holds: A and A′ are quadratic twists of each other if and only if, for almost ...

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    Probability of Occurrence of Some Planar Random Quasi-homogeneous Vector Fields 

    Coll, B.; Gasull, A.; Prohens, R. (Publication date: 2022-11-06)

    The objective of this work is the study of the probability of occurrence of phase portraits in a family of planar quasi-homogeneous vector fields of quasi degree q, that is a natural extension of planar linear vector fields, ...

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    Left-censored recurrent event analysis in epidemiological studies: a proposal for when the number of previous episodes is unknown 

    Hernández-Herrera, G.; Moriña, D.; Navarro, A. (Publication date: 2022-01-16)

    Background: When dealing with recurrent events in observational studies it is common to include subjects who became at risk before follow-up. This phenomenon is known as left censoring, and simply ignoring these prior ...

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    Bifurcation of limit cycles in piecewise quadratic differential systems with an invariant straight line 

    da Cruz, L.P.C.; Torregrosa, J. (Publication date: 2022-10-01)

    We solve the center-focus problem in a class of piecewise quadratic polynomial differential systems with an invariant straight line. The separation curve is also a straight line which is not invariant. We provide families ...

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    Semilinear formulation of a hyperbolic system of partial differential equations 

    Barril, C.; Calsina, À. (Publication date: 2022-06-29)

    In this paper, we solve the Cauchy problem for a hyperbolic system of first-order PDEs defined on a certain Banach space X. The system has a special semilinear structure because, on the one hand, the evolution law can be ...

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    b-Structures on Lie groups and Poisson reduction 

    Braddell, R.; Kiesenhofer, A.; Miranda, E. (Publication date: 2022-05-01)

    Motivated by the group of Galilean transformations and the subgroup of Galilean transformations which fix time zero, we introduce the notion of a b-Lie group as a pair (G,H) where G is a Lie group and H is a codimension-one ...

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    Lognormals, power laws and double power laws in the distribution of frequencies of harmonic codewords from classical music 

    Serra-Peralta, M.; Serrà, J.; Corral, Á. (Publication date: 2022-02-16)

    Zipf’s law is a paradigm describing the importance of different elements in communication systems, especially in linguistics. Despite the complexity of the hierarchical structure of language, music has in some sense an ...

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    Normalization of Blood Viscosity According to the Hematocrit and the Shear Rate 

    Trejo-Soto, C.; Hernández-Machado, A. (Publication date: 2022-02-24)

    The rheological properties of blood depend highly on the properties of its red blood cells: concentration, membrane elasticity, and aggregation. These properties affect the viscosity of blood as well as its shear thinning ...

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    First-order perturbation for multi-parameter center families 

    Itikawa, J.; Oliveira, R.; Torregrosa, J. (Publication date: 2022-02-05)

    In the weak 16th Hilbert problem, the Poincaré-Pontryagin-Melnikov function, M1(h), is used for obtaining isolated periodic orbits bifurcating from centers up to a first-order analysis. This problem becomes more difficult ...

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    Dynamics of the Secant map near infinity 

    Garijo, A.; Jarque, X. (Publication date: 2022-03-07)

    IWe investigate the root finding algorithm given by the Secant method applied to a real polynomial p of degree k as a discrete dynamical system defined on (Formula presented.). We extend the Secant map to the real projective ...