Examinando por Materia "Ondas"
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- PublicaciónAcceso abiertoAnálisis de la incidencia de los valores de tortuosidad en la precisión del modelo matemático de Allard y Champoux para calcular el coeficiente de absorción de materiales a partir de mediciones de tortuosidad, realizadas mediante el método de ultrasonido desarrollado por Paolo Bonfiglio y Francesco Pompoli(2016) Rodríguez Velásquez, Daniel; Garza Agudelo, Diana MaríaThis project seeks to analyze the incidence of tortuosity values in the accuracy of the mathematical model of Allard and Champoux to calculate the absorption coefficient of materials from measurements of tortuosity, performed by ultrasound method developed by Paolo Bonfiglio and Francesco Pompoli; for this was done a characterization of the device and preliminary measurements in order to verify the correct operation of the measurement system. The results of the analysis showed that the values of tortuosity influence the calculation of the absorption coefficient of materials however it was not possible to determine whether this dependence between both values is directly or inversely proportional. Grupo de Investigación: Modelamiento y Simulación Computacional. -- Línea de Investigación: Acústica y Procesamiento de Señales. -- Área: acústica. -- Tema: tortuosidad.
- PublicaciónAcceso abiertoAnálisis de métricas para la evaluación del campo difuso(2020) Rodríguez, Marcelo Zapata; Murillo Gómez, Diego MauricioIn the present project .Analysis of metrics for the evaluation of the diffuse field”, the different metricsand parameters are evaluated to determine a diffuse field. Then the theories, procedures and results ofthe evaluation of the different metrics are exposed, taking into account to the procedures of internationalregulations. A proposal for the estimation and analysis of the diffuse field is presented, considering thevalues calculated in each metric In order to verify the applicability of this proposal. The results obtainedby the different metrics were compared. The levels of sound pressure, standard deviation, cross correlationvalue and entropy value are compared for each sound field case. Several sound fields are recreated usingvarious methodologies, and finally the relationship between frequency, standard deviation is shown. andentropy for a sound field.
- PublicaciónAcceso abiertoDiseño e implementación de un sistema de comunicación subacuática basado en la emisión y recepción de señales en el rango de frecuencias de ultrasonido(2017) Uribe Gómez, Andrés Felipe; Vélez Hurtado, Javier Alberto; Meneses Benavides, GustavoCommunications in marine environments represent a special case within information transmission and reception systems, given the characteristics of the medium that obviously affect the propagation of radio signals, resulting in a predominance, at least in submarine implementations, Acoustic wave or optical link based communications. It is proposed to implement an underwater communications system which is based on ultrasonic waves and which can be used in telemetry applications or the like, having a relatively low transmission rate. In order to verify the effectiveness and performance of such systems, the design and implementation of an acoustic source underwater will be carried out and controlled by electronic circuits for the transmission of information. The reception will be carried out with the aid of an arrangement of hydrophones and electronic demodulation-decoding circuits. Alternatively, you can use computer equipment, data acquisition cards, development platforms that use processors of 32 or more bits, or similar devices to assist in the reception stage when the transmission scheme so requires. It is hoped to contribute with this work to an area that has few registers of study and experimentation at local level, also looks for to find new possibilities for systems of telemetry in marine environments that can be adapted to different scenarios that require of underwater communication. The fields of application and experimentation for underwater communication solutions range from the control and monitoring of remotely operated submarine vehicles to underwater sensor networks, to name a few.
- PublicaciónAcceso abiertoGeneración de tomografías 2D de la tierra por medio de inversión de onda completa FWI utilizando SPECFEM 2D Cartesian(2020) Pulgarín Suárez, Diego Alexander; Berrío Ríos, David; Franco Bedoya, Ramiro EstebanThis work shows the procedure for the creation of a 2D tomography of the earth from the joint methodcalled full-wave inversion (FWI), for this, two experiments are carried out, the first one on a syntheticterrain called ’Checkers’ and the second one on a real flat terrain. A workflow is established, consistingof a stage of obtaining reference data, one of initial model creation, one of signal preprocessing andfinally one of iterative simulation and optimization. The results of both experiments are presented andan error analysis is made between the synthetic terrain model obtained and the actual synthetic terrainmodel to determine the effectiveness of the proposed workflow. Finally, the real terrain model obtained iscompared with data from two wells previously excavated at the site. The results identify the strengths andweaknesses of the method in terms of distribution of sources and receivers, initial model used, analyzedfrequency bandwidth of the signals and discretization times
- PublicaciónAcceso abiertoReconstrucción del campo sonoro basado en ondas planas(2020) Montoya Sánchez, Daniel José; Murillo Gómez, Diego Mauriciohis project studies the synthesis of the acoustic field based on a representation of plane waves. The method consists of the formulation of an inverse problem in which the amplitude of the plane waves is calculated from a virtual array of microphones. Since the discretization of the plane wave expansion limits the area in which the reconstruction of the sound field is valid, it proposes a methodology based on multiple expansions that extend the area of reconstruction. In addition, an analysis of the effect produced by the application of regularization on the formulation of the inverse problem is considered. The present methodology enables the generation of real-time auralizations in which the listener can be moved interactively in a virtual environment.