Browsing by Autor "Paula Caycedo"

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    Algorithms with low computational cost for monitoring and analysis of Colombia soundscapes
    (2015) Luis Alfredo Quiroz; Luis Tobòn; Paula Caycedo; Oscar Laverde-R.
    Studies focused on soundscape are important on biological conservation, because natural sounds are permanent and with dynamic properties, they have been linked to the welfare of the environment and the structure of the landscape. These studies usually analyze the sound in time and frequency domains, with computationally heavy and centralized algorithms. However, new technologies for real time analysis requires distributed algorithms with low computational cost. Hence, the present work evaluates the computational cost of alternative methods with potential applicability in analysis of time-varying signals. The analyzed methods are short time Fourier transform, harmonic expansion, wavelet transform (analytical and non-analytical Morlet, Mexican hat, and Paul) and orthogonal polynomial expansion (Legendre, Chebyshev, and Hermite). A comparison between these methods is presented, in which processing time, memory consumption, quality of reconstruction and grouping index are some of the features selected, resulting in a useful computational cost ranking. The methods are applied to several signals generated with different procedures, such as artificial modulated signals and natural recorded sounds (provided by The Alexander von Humboldt Institute). In conclusion, Harmonic expansion, Chebyshev expansion, Legendre expansion and Short Time Fourier Transform are the best methods with excellent performance in all features.
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    Henicorhina anachoreta (Troglodytidae), another endemic bird species for the Sierra Nevada de Santa Marta, Colombia
    (2021) Carlos Daniel Cadena; Maria Leitner; Paula Caycedo; Andrés M. Cuervo; Rauri C. K. Bowie; Hans Slabbekoorn
    En un estudio previo, presentamos evidencia que el cucaracho del género Henichorhina que habita las elevaciones superiores de la Sierra Nevada de Santa Marta, H. anachoreta, amerita el rango de una especie distinta del táxon de elevaciones más bajas, H. bangsi, con base en diferencias genéticas y fenotípicas y de sus cantos. Además, encontramos que, en una zona estrecha de simpatría, ellos mostraron respuestas diferentes a sus propios cantos vs. los del otro taxon. Sin embargo, no presentamos en detalle las diferencias en plumaje y medidas morfométricas y no presentamos una recomendación taxonómica formal. Aquí hacemos tal recomendación y describimos en detalle las diferencias en plumaje y mediciones para apoyar esta recomendación.