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    • openAccess   Nearest neighbour distance matching Leave-One-Out Cross-Validation for map validation 

      Milà, Carles; Mateu, Jorge; Pebesma, Edzer; Meyer, Hanna John Wiley & Sons Ltd on behalf of British Ecological Society (2022-03-28)
      1. Several spatial and non-spatial Cross-Validation (CV) methods have been used to perform map validation when additional sampling for validation purposes is not possible, yet it is unclear in which situations one CV ...

    • openAccess   NeuroNorm: An R package to standardize multiple structural MRI 

      Payares-Garcia, David; Mateu, Jorge; Schick, Wiebke Elsevier (2023)
      Preprocessing of structural MRI involves multiple steps to clean and standardize data before further analysis. Typically, researchers use numerous tools to create tailored preprocessing workflows that adjust to their ...

    • openAccess   New anallytic approximations based on the Magnus expansion 

      Sánchez, S.; Casas, Fernando; Fernández, A. Springer Science+Business Media, LLC (2011-09)
      The Magnus expansion is a frequently used tool to get approximate analytic solutions of time-dependent linear ordinary differential equations and in particular the Schrödinger equation in quantum mechanics. However, the ...

    • openAccess   New and improved orbits of historical comets: Late 4th and 5th century 

      Marco Castillo, Francisco José; Martínez Usó, María José; Sicoli, Piero; Gorelli, Roberto Elsevier (2022-05-22)
      Since as early as the 19th century, many scholars have devoted themselves to the calculation of sets of orbital elements for particular historical comets. In many cases, these studies have led to proposing orbits that have ...

    • closedAccess   New and old facts about entropy in uniform spaces and topological groups 

      Sanchis López, Manuel; Virili, Simone; Dikranjan, Dikran Elsevier (2012-04)
      In 1965 Adler, Konheim and McAndrew defined the topological entropy of a continuous self-map of a compact space. In 1971 Bowen extended this notion to uniformly continuous self-maps of (not necessarily compact) metric ...

    • openAccess   New binary and ternary LCD codes 

      Galindo, Carlos; Geil, Olav; Hernando, Fernando; Ruano, Diego IEEE (2018-05-09)
      LCD codes are linear codes with important cryptographic applications. Recently, a method has been presented to transform any linear code into an LCD code with the same parameters when it is supported on a finite field ...

    • openAccess   New Conditions on Maximal Invariant Subgroups That Imply Solubility 

      Beltrán, Antonio; shao, Changguo Springer (2023)
      Let G be a finite group and assume that a finite group of automorphisms A acts on G, such that the orders of A and G are relatively prime. We prove that the fact of imposing certain conditions on the set of maximal A-invariant ...

    • openAccess   New families of symplectic splitting methods for numerical integration in dynamical astronomy 

      Blanes, Sergio; Casas, Fernando; Farrés Basiana, Ariadna; Laskar, Jacques; Makazaga, Joseba; Murua, Ander Elsevier (2013-06)
      We present new splitting methods designed for the numerical integration of near-integrable Hamiltonian systems, and in particular for planetary N-body problems, when one is interested in very accurate results over a large ...

    • openAccess   New quantum codes from evaluation and matrix-product codes 

      Galindo, Carlos; Hernando, Fernando; Ruano, Diego Elsevier (2014-07)
      Stabilizer codes obtained via CSS code construction and Steane's enlargement of subfield-subcodes and matrix-product codes coming from generalized Reed-Muller, hyperbolic and affine variety codes are studied. Stabilizer ...

    • openAccess   New rotational integrals in space forms, with an application to surface area estimation 

      Gual-Arnau, Ximo; Cruz-Orive, Luis M. Springer (2016-08)
      A surface area estimator for three-dimensional convex sets, based on the invariator principle of local stereology, has recently motivated its generalization by means of new rotational Crofton-type formulae using Morse ...

    • openAccess   Newton method for symmetric quartic polynomial 

      Campos, Beatriz; Garijo, Antonio; Jarque, Xavier; Vindel, Pura Elsevier (2016-11)
      We investigate the parameter plane of the Newton’s method applied to the family of quartic polynomials pa,b(z)=z4+az3+bz2+az+1,pa,b(z)=z4+az3+bz2+az+1, where a and b are real parameters. We divide the parameter plane ...

    • openAccess   Newton–Okounkov bodies of exceptional curve valuations 

      Galindo, Carlos; Moyano-Fernández, Julio José; Monserrat, Francisco; Nickel, Matthias European Mathematical Society (2020-03-20)
      We prove that the Newton–Okounkov body associated to the flag E∙:={X=Xr⊃Er⊃{q}}, defined by the surface X and the exceptional divisor Er given by any divisorial valuation of the complex projective plane P2, with respect ...

    • openAccess   Nilpotency of normal subgroups having two G-class sizes 

      Alemany, Elena; Beltrán, Antonio; Felipe, Maria José American Mathematical Society (2010-12-22)
      Let G be a finite group. If N is a normal subgroup which has exactly two G-conjugacy class sizes, then N is nilpotent. In particular, we show that N is abelian or is the product of a p-group P by a central subgroup of G. ...

    • closedAccess   Nilpotent and Abelian Hall Subgroups in Fintie Groups 

      Beltrán, Antonio; Felipe, Maria José; Malle, Gunter; Moretó, Alexander; Navarro, Gabriel; Sanus, Lucia; Solomon, Ronald; Tiep, Pham Huu American Mathematical Society (2015-07)
      We give a characterization of the finite groups having nilpotent or abelian Hall π-subgroups that can easily be verified using the character table.

    • openAccess   NMS Flows on S3 with no Heteroclinic Trajectories Connecting Saddle Orbits 

      Vindel, Pura; Campos, Beatriz Springer Verlag (2012)
      In this paper we find topological conditions for the non existence of heteroclinic trajectories connecting saddle orbits in non singular Morse-Smale flows on S 3 . We obtain the non singular Morse-Smale flows that can be ...

    • openAccess   No-go theorems for photon state transformations in quantum linear optics 

      V. Parellada, Pablo; Gimeno i Garcia, Vicent; Moyano-Fernández, Julio José; Garcia-Escartin, Juan Carlos Elsevier (2023)
      We give a necessary condition for photon state transformations in linear optical setups preserving the total number of photons. From an analysis of the algebra describing the quantum evolution, we find a conserved quantity ...

    • openAccess   Non equivalence of NMS flows on S3 

      Campos, Beatriz; Vindel, Pura Matematicky ustav Akademie ved Ceské republiky (2012)
      We build the flows of non singular Morse-Smale systems on the 3-sphere from its round handle decomposition. We show the existence of flows corresponding to the same link of periodic orbits that are non equivalent. So, the ...

    • openAccess   Non-homogeneous temporal Boolean models to study endocytosis 

      Ibáñez Gual, Maria Victoria; Simó, Amelia; Gallego, María Ángeles Elsevier (2012)
      Many medical and biological problems require the analysis of large sequences of microscope images, these images capture phenomena of interest and it is essential to characterize their spatial and temporal properties. The ...

    • openAccess   Non-linear spatial modeling of rat sightings in relation to urban multi-source foci 

      Ayyad, Carlos; Mateu, Jorge; Tamayo Uria, Ibon Elsevier (2018-06)
      The brown rat has been living with humans in a wide variety of environmental contexts; it adversely affects public health by transmission of pathogens that can cause human diseases and allergies. Understanding behavioral ...

    • openAccess   Non-positive and negative at infinity divisorial valuations of Hirzebruch surfaces 

      Galindo, Carlos; Monserrat, Francisco; Moreno Ávila, Carlos Jesús Springer Verlag (2020-05)
      We consider rational surfaces Z defined by divisorial valuations ν of Hirzebruch surfaces. We introduce concepts of non-positivity and negativity at infinity for these valuations and prove that these concepts admit nice ...