Ara es mostren els items 1-18 de 18

    • A contour based approach for bilateral mammogram registration using discrete wavelet analysis 

      Reig Bolano, Ramon; Parisi Baradad, Vicenç; Marti Puig, Pere (2009)
      Article
      Accés restringit per política de l'editorial
      Registration of mammograms is an essential step to increase the effectiveness of all screening programs planned to early detect breast cancer in asymptomatic women. New techniques based on data fusion of different spatial ...
    • A fast OFDM-CDMA user demultiplexing architecture 

      Marti Puig, Pere; Sala Álvarez, José (Institute of Electrical and Electronics Engineers (IEEE), 2000)
      Text en actes de congrés
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      A fast algorithm based on a butterfly structure is presented that demultiplexes the symbols of a particular type of MC-MA (multi-carrier multiple-access) modulation previously proposed for indoor radio communications. A ...
    • A new otolith image contour descriptor based on partial reflection 

      Reig Bolano, Ramon; Marti Puig, Pere; Lombarte, A.; Soria Pérez, José Antonio; Parisi Baradad, Vicenç (2010-12)
      Article
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      In this paper we propose a new contour descriptor for reconstructing fish otolith contours that uses half the number of coefficients needed by the classical elliptical Fourier descriptors (EFDs) for the same accuracy. ...
    • A recursive approach to multiscalar data interpolation of sparsely sampled sea surface measurements at different spatial resolutions 

      Reig Bolano, Ramon; Garcia Ladona, E.; Parisi Baradad, Vicenç; Marti Puig, Pere (2008)
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      In many oceanographic studies there is a need to reconstruct a signal from a set of sparse measurements. We propose an algorithm to iteratively approximate the intermediate values between irregularly sampled data, when ...
    • A text-mining approach to assess the failure condition of wind turbines using maintenance service history 

      Blanco Martínez, Alejandro; Marti Puig, Pere; Gibert, Karina; Cusidó Roura, Jordi; Sole Casals, Jordi (2019-05-23)
      Article
      Accés obert
      Detecting and determining which systems or subsystems of a wind turbine have more failures is essential to improve their design, which will reduce the costs of generating wind power. Two of the most critical failures, the ...
    • Coding of biosignals using the discrete wavelet decomposition 

      Reig Bolano, Ramon; Marti Puig, Pere; Solé-Casals, Jordi; Zaiats, Vladimir; Parisi Baradad, Vicenç (Springer, 2009)
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      Wavelet derived codification techniques are widespread used in image codifiers. The wavelet based compression methods are adequate for representing transients. In this paper we explore the use of the discrete wavelet transform ...
    • Data compression of natural signals based on discrete wavelet transform analysis 

      Reig Bolano, Ramon; Marti Puig, Pere; Solé-Casals, Jordi; Parisi Baradad, Vicenç (2009)
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      In this paper we explore the use of the discrete wavelet transform analysis of an arbitrary signal in order to improve the data compression capability of data coders. Wavelet analysis is widespread used in image codifiers, ...
    • Detection of Wind Turbine Failures through Cross-Information between Neighbouring Turbines 

      Marti Puig, Pere; Cusidó Roura, Jordi; Lozano, Francico J.; Serra Serra, Moisès; Caiafa, Cesar F.; Sole Casals, Jordi (Multidisciplinary Digital Publishing Institute, 2022-10-01)
      Article
      Accés obert
      In this paper, the time variation of signals from several SCADA systems of geographically closed turbines are analysed and compared. When operating correctly, they show a clear pattern of joint variation. However, the ...
    • Effects of the pre-processing algorithms in fault diagnosis of wind turbines 

      Marti Puig, Pere; Blanco Martínez, Alejandro; Cárdenas Araújo, Juan José; Cusidó Roura, Jordi; Sole Casals, Jordi (Elsevier, 2018-12)
      Article
      Accés obert
      The wind sectors pends roughly 2200M€ in repair the wind turbines failures. These failures do not contribute to the goal of reducing greenhouse gases emissions. The 25–35% of the generation costs are operation and maintenance ...
    • Efficient cubic spline interpolation implemented with FIR filters 

      Ferrer Arnau, Luis Jorge; Reig Bolano, Ramon; Marti Puig, Pere; Manjabacas, A.; Parisi Baradad, Vicenç (2012-06-26)
      Article
      Accés obert
      Classical Cubic spline interpolation needs to solve a set of equations of high dimension. In this work we show how to compute the interpolant using a FIR digital filter, with a reduced number of operations per interpolated ...
    • Efficient representation of contours using splines implemented with FIR filters 

      Ferrer Arnau, Luis Jorge; Parisi Baradad, Vicenç; Reig Bolano, Ramon; Marti Puig, Pere; Manjabacas, A. (2011)
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      The interpolation of contour pixels, with splines, of an order greater than or equal to two, usually causes oscillations that do not fit the original shape. To overcome this we propose using a least squares filter before ...
    • Exploratory analysis of SCADA data from wind urbines using the K-Means clustering algorithm for predictive maintenance purposes 

      Cosa Rodríguez, Pablo; Marti Puig, Pere; Caiafa, Cesar F.; Serra Serra, Moisès; Cusidó Roura, Jordi; Sole Casals, Jordi (2023-02-10)
      Article
      Accés obert
      Product maintenance costs throughout the product’s lifetime can account for between 30–60% of total operating costs, making it necessary to implement maintenance strategies. This problem not only affects the economy but ...
    • Feature Selection Algorithms for Wind Turbine Failure Prediction 

      Marti Puig, Pere; Blanco Martínez, Alejandro; Cárdenas Araújo, Juan José; Cusidó Roura, Jordi; Sole Casals, Jordi (2019-01-31)
      Article
      Accés obert
      It is well known that each year the wind sector has profit losses due to wind turbine failures and operation and maintenance costs. Therefore, operations related to these actions are crucial for wind farm operators and ...
    • Feature selection for analyzing and retrieving fish otoliths using elliptic Fourier descriptors of shapes 

      Reig Bolano, Ramon; Marti Puig, Pere; Gallego, Esteve; Masferrer, Gerard; Lombarte, A.; Ferrer Arnau, Luis Jorge; Parisi Baradad, Vicenç (2011)
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      This paper analyzes the characteristics of an experimental otolith retrieval system based on image contours described with Elliptical Fourier Descriptors (EFD). Otoliths are found in the inner ear of fish. Their shape ...
    • Identifying health status of wind turbines by using self organizing maps and interpretation-oriented post-processing tools 

      Blanco, Alejandro; Gibert, Karina; Marti Puig, Pere; Cusidó Roura, Jordi; Sole Casals, Jordi (2018-04-01)
      Article
      Accés obert
      Identifying the health status of wind turbines becomes critical to reduce the impact of failures on generation costs (between 25–35%). This is a time-consuming task since a human expert has to explore turbines individually. ...
    • Otoliths identifiers using image contours EFD 

      Reig Bolano, Ramon; Marti Puig, Pere; Rodríguez González, Sara; Bajo Pérez, Javier; Parisi Baradad, Vicenç; Lombarte, A. (Springer Berlín / Heidelberg, 2010-09)
      Article
      Accés restringit per política de l'editorial
      In this paper we analyze the characteristics of an experimental otolith identification system based on image contours described with Elliptical Fourier Descriptors (EFD). Otoliths are found in the inner ear of fishes. ...
    • Radix-R FFT and IFFT factorizations for parallel implementation 

      Marti Puig, Pere; Reig Bolano, Ramon; Parisi Baradad, Vicenç (2009)
      Article
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      Two radix-R regular interconnection pattern families of factorizations for both the FFT and the IFFT -also known as parallel or Pease factorizations- are reformulated and presented. Number R is any power of 2 and N, the ...
    • Surface parameterization for smooth 3D shapes 

      Marti Puig, Pere; Reig Bolano, Ramon; Manjabacas, A.; Ferrer Arnau, Luis Jorge; Parisi Baradad, Vicenç; Lombarte, A. (2011)
      Text en actes de congrés
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      In this work we present a new method for compacting data from 3D shapes by extracting a 3D characteristic curve that we call a 3D signature. The 3D signature obtained preserves almost all the morphological shape ...