Exploració per tema "Fractals"

Ara es mostren els items 3-22 de 72

    • A genetic algorithm optimized fractal model to predict the constriction resistance from surface roughness measurements 

      Capelli, Francesca; Riba Ruiz, Jordi-Roger; Rupérez de Gracia, Elisa; Sanllehí, Josep (2017-06-09)
      Article
      Accés obert
      The electrical contact resistance greatly influences the thermal behavior of substation connectors and other electrical equipment. During the design stage of such electrical devices, it is essential to accurately predict ...

    • A microstrip array operating in a fracton mode [fractal geometry] 

      Anguera Pros, Jaume; Montesinos, Gemma; Puente Baliarda, Carles; Borja, C.; Soler, Jordi (Institute of Electrical and Electronics Engineers (IEEE), 2003)
      Text en actes de congrés
      Accés restringit per política de l'editorial
      A high-directivity microstrip array using multilevel elements based on a fractal geometry is theoretically compared with one using a circular patches. Within the same electrical area, the same directivity can be obtained. ...

    • A simple scaling analysis of rainfall in Andalusia (Spain) under different precipitation regimes 

      Casas Castillo, M. del Carmen; Rodríguez Solá, Raúl; Llabrés Brustenga, Alba; García Marín, Amanda Penélope; Estévez Gualda, Javier; Navarro Bosque, Javier (2022-04-16)
      Article
      Accés obert
      A simple scaling analysis was performed in Andalusia (Spain) using daily records from 377 selected stations covering the temporal period between 1870 and 2018. Since Andalusia is a region of considerable climatic variety, ...

    • A stochastic hybrid model with a fast concentration bias for chemotactic cellular attraction 

      Ojer Ferrer, Jaume; García López, Alvaro; Used, Javier; Fernández Sanjuan, Miguel Angel (2022-03)
      Article
      Accés obert
      We reproduce the phenomenon of chemotaxis through a hybrid random walk model in two dimensions on a lattice. The dynamics of the chemoattractant is modelled using a partial differential equation, which reproduces its ...

    • A study of the scaling properties of rainfall in spain and its appropriateness to generate intensity-duration-frequency curves from daily records 

      Rodríguez Solá, Raúl; Casas Castillo, M. del Carmen; Navarro Bosque, Javier; Redaño Xipell, Angel (John Wiley & Sons, 2016-04-20)
      Article
      Accés obert
      A methodology based on the fractal properties of rainfall has been applied to obtain the intensity-duration-frequency, IDF, curves for 100 pluviometric Spanish stations over the Iberian Peninsula and the Balearic Islands ...

    • An algebraic fractal approach to Collatz Conjecture 

      Martín Chabrera, Víctor (Universitat Politècnica de Catalunya, 2019-05)
      Treball Final de Grau
      Accés obert
      The Collatz conjecture is one of the most easy-to-state unsolved problems in Mathematics today. It states that after a finite number of iterations of the Collatz function, defined by C(n) = n/2 if n is even, and by C(n) = ...

    • An iterative model for fractal antennas: application to the Sierpinski gasket antenna 

      Puente Baliarda, Carles; Borja Borau, M.Carmen; Navarro Rodero, Mònica; Romeu Robert, Jordi (IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC, 2000-05-31)
      Article
      Accés obert
      A simple model that explains the behavior of the Sierpinski fractal antenna is presented. This model shows that the multiband behavior of the Sierpinski fractal antenna is a consequence of its fractal nature. The model is ...

    • Análisis de geometrías fractales para resonadores microstrip 

      Extremera Extremera, Manuel Jesus (Universitat Politècnica de Catalunya, 2016-02-25)
      Projecte/Treball Final de Carrera
      Accés obert
      Usage and popularity growth of communications satellites has increased the interest on filter synthesis research. Nowadays, the improvement of the trade-off between size, weight, cost and performance is the golden rule. ...

    • Análisis multifractal de procesos autosimilares : imágenes de satélite e inestabilidades baroclinas 

      Redondo Apraiz, José Manuel; Busquets Grau, Joan; Platónov, Alexéi Konstantínovich; Garzón Bedoya, Germán (2008-05-05)
      Article
      Accés obert

    • Antenes de Grafè Fractal orientades a Network-on-Chip 

      Martinavarro Armengol, Àlex (Universitat Politècnica de Catalunya, 2018-02)
      Treball Final de Grau
      Accés obert
      Realitzat a/amb:   NanoNetworking Center in Catalunya
      This work treats in depth the possibility and restrictions of making antennas in order to communicate the cores of a massive multicore processor. Since these must be commensurable with the processor, we will perform ...

    • Atmospheric-turbulence-induced power-fade statistics for a multiaperture optical receiver 

      Belmonte Molina, Aniceto; Comerón Tejero, Adolfo; Rubio, Juan Antonio; Fernández (OPTICAL SOC AMER, 1997-01-31)
      Article
      Accés obert
      To estimate the probability distributions of power fades, we consider two basic types of disturbance in electromagnetic wave propagation through atmospheric turbulence: wave-front intensity fluctuations and wave-front ...

    • Automatic Computation of Potential Tumor Regions in Cancer Detection using Fractal analysis techniques 

      Orellana Bech, Bernat (Universitat Politècnica de Catalunya, 2009-09-08)
      Projecte Final de Màster Oficial
      Accés obert
      Radiology is one of the most active and technologically advanced fields in medicine. It was born from the most advanced physics concepts, and it became a reality thanks to the state-of-the art of electronics and computer ...

    • Breakage of an artificial crushable material under loading 

      Casini, Francesca; Viggiani, Giulia M.B.; Springman, Sarah Marcella (2013-10)
      Article
      Accés restringit per política de l'editorial
      The mechanical behaviour of granular materials depends on their grading. Crushing of particles under compression or shear modifies the grain size distribution, with a tendency for the percentage of fine material to increase. ...

    • Comments on "On the relationship between fractal dimension and the performance of multi-resonant dipole antennas using Koch curves" 

      González Arbesú, José María; Rius Casals, Juan Manuel; Romeu Robert, Jordi (IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC, 2004-06-30)
      Working paper
      Accés obert
      Comentaris referits a l'article següent: K. J. Vinoy, J. K. Abraham, and V. K. Varadan, “On the relationship between fractal dimension and the performance of multi-resonant dipole antennas using Koch curves,” IEEE ...

    • Complexity and predictability of the monthly Western Mediterranean oscillation index 

      Lana Pons, Francisco Javier; Burgueño Rivero, August; Martínez Santafé, Maria Dolors; Serra de Larrocha, Carina (Wiley, 2016-05)
      Article
      Accés obert
      The complexity, predictability and predictive instability of the Western Mediterranean Oscillation index (WeMOi) at monthly scale, years 1856-2000, are analysed from the viewpoint of monofractal and multifractal theories. ...

    • Damage diagnosis for offshore wind turbine foundations based on the fractal dimension 

      Hoxha, Ervin; Vidal Seguí, Yolanda; Pozo Montero, Francesc (2020-10-05)
      Article
      Accés obert
      Cost-competitiveness of offshore wind depends heavily in its capacity to switch preventive maintenance to condition-based maintenance. That is, to monitor the actual condition of the wind turbine (WT) to decide when and ...

    • Dimensional Synthesis of Wristed Binary Hands 

      Hassanzadeh, Neda; Pérez Gracia, Alba (2016-04)
      Article
      Accés obert
      The kinematic synthesis applied to tree topologies is a tool for the design of multi-fingered robotic hands, for a simultaneous task of all fingertips. Even though traditionally wrists and hands have been designed separately, ...

    • Diseño de una agrupación de antenas parche para un sistema radiante en la banda de 2.45 GHz 

      Fernandez Tarifa, Ismael Joshua (Universitat Politècnica de Catalunya, 2021-09-10)
      Treball Final de Grau
      Accés restringit per decisió de l'autor

    • Dual-band Sierpinski fractal monopole antenna 

      Romeu Robert, Jordi (Institute of Electrical and Electronics Engineers (IEEE), 2000)
      Text en actes de congrés
      Accés obert
      A new top-loaded reduced-sized dual-band (1.9 GHz and 3.5 GHz) monopole antenna for wireless communications is presented. The antenna provides better than -15 dB input return loss and keeps the same radiation pattern over ...

    • Edge effect causes apparent fractal correlation dimension of uniform spatial raindrop distribution 

      Uijlenhoet, Remko; Porra, J. M.; Sempere Torres, Daniel; Creutin, Jean-Dominique (University of Thechnology and Agriculture Nicholas Copernicus University, 2009-04)
      Article
      Accés obert
      Lovejoy and Schertzer (1990a) presented a statistical analysis of blotting paper observations of the (twodimensional) spatial distribution of raindrop stains. They found empirical evidence for the fractal scaling behavior ...