[1] | Pu Y F. Research on application of fractional calculus to latest signal analysis and processing (in Chinese). Doctor dissertation. Chengdu: Sichuan University, 2006 |

[2] | Pu Y F. Application of fractional differential approach to digital image processing. J Sichuan Univ (Eng Sci Ed) (in Chinese), 2007, 39(3): 124–132 |

[3] | Pu Y F, Wang W X. The fractional differential mask of digital image and its numerical implementation algorithm. Acta Autom Sin (in Chinese), 2007, 33(11): 1128–1135 |

[4] | Pu Y F. Fractional Differential Filter of Digital Image. Invention Patent of China, No.200610021702. 2006 |

[5] | Pu Y F, Yuan X, Liao K, et al. Five numerical algorithms of fractional calculus applied in modern signal analyzing and processing. J Sichuan Univ (Eng Sci Ed) (in Chinese), 2005, 37(5): 118–124 |

[6] | Pu Y F, Yuan X, Liao K, et al. Structuring analog fractance circuit for 1/2 order fractional calculus. In: Proceedings of 6th International Conference on ASIC. Shanghai: IEEE, 2005. 1039–1042 |

[7] | Pu Y F. Implement any fractional order multilayer dynamics associative neural network. In: Proceedings of 6th International Conference on ASIC. Shanghai: IEEE, 2005. 635–638 |

[8] | Pu Y F, Yuan X, Liao K, et al. A recursive net-grid-type analog fractance circuit for any order fractional calculus. In: Proceedings of IEEE International Conference on Mechatronics and Automation. Canada: IEEE, 2005. 1375–1380 |

[9] | Pu Y F, Yuan X, Liao K, et al. Determination of scale sample step for getting numerical result of the continuous wavelet transform. J Sichuan Univ (Eng Sci Ed) (in Chinese), 2004, 36(6): 111–116 |

[10] | Pu Y F, Yuan X, Liao K, et al. Implement any fractional order neural-type pulse oscillator with net-grid type analog fractance circuit. J Sichuan Univ (Eng Sci Ed) (in Chinese), 2006, 38(1): 128–132 |

[11] | Yuan X, Chen X D, Li Q L, et al. Differential operator and the construction of wavelet. Acta Electr Sin (in Chinese), 2002, 30(5): 769–773 |

[12] | Kenneth F (Composing), Zeng W Q, Liu S Y (Translating). Fractal Geometry Mathematical Foundations and Applications. Liaoning: Northeast Industrial Press, 1991 |

[13] | Oldham K B, Spanier J. The Fractional Calculus. New York and London: Academic Press, 1974 |