Papers by José Manuel Antunes
In this work we propose a new and straightforward method to estimate the unknown terms of incompl... more In this work we propose a new and straightforward method to estimate the unknown terms of incomplete spectral or correlation system response matrices, when the cross-spectra or crosscorrelations available from multiple measurements do not cover all pairs of transducer locations. The proposed technique may be applied whenever the available data includes selected auto-spectra and cross-spectra implicating all measurement locations. The proposed spectral estimation formulation is illustrated on a realistic simulation of a multi-supported tube subjected to turbulence excitation from cross-flow. Finally, we show the effectiveness of the proposed technique by extracting the modal responses of the simulated flow-excited tube from a reconstructed response matrix, using the SOBI method.
Acta acustica united with …, 2006
Tibetan bowls have been traditionally used for ceremonial and meditation purposes, but are also i... more Tibetan bowls have been traditionally used for ceremonial and meditation purposes, but are also increasingly being used in contemporary music-making. They are handcrafted using alloys of several metals and produce different tones, depending on the alloy composition, their shape, size and weight. Most important is the soundproducing technique used-either impacting or rubbing, or both simultaneously-as well as the excitation location, the hardness and friction characteristics of the exciting stick (called puja). Recently, researchers became interested in the physical modelling of singing bowls, using waveguide synthesis techniques for performing numerical simulations. Their efforts aimed particularly at achieving real-time synthesis and, as a consequence, several aspects of the physics of these instruments do not appear to be clarified in the published numerical formulations and results. In the present paper, we extend to axi-symmetrical shells-subjected to impact and friction-induced excitations-our modal techniques of physical modelling, which were already used in previous papers concerning plucked and bowed strings as well as impacted and bowed bars. We start by an experimental modal identification of three different Tibetan bowls, and then develop a modelling approach for these systems. Extensive nonlinear numerical simulations were performed, for both impacted and rubbed bowls, which in particular highlight important aspects concerning the spatial patterns of the frictioninduced bowl vibrations. Our results are in good agreement with preliminary qualitative experiments.
Singing bowls are traditionally made in Tibet, Nepal, India, China and Japan. Although the name q... more Singing bowls are traditionally made in Tibet, Nepal, India, China and Japan. Although the name qing has been applied to lithophones since the Han Chinese Confucian rituals, more recently it also designates the bowls used in Buddhist temples. In the Himalaya there is a very ancient tradition of metal manufacture, and bowls have been handcrafted using alloys of several metals - mainly copper and tin, but also other metals such as gold, silver, iron, lead, etc. - each one believed to possess particular spiritual powers.
V. Debut , J. Antunes , P. Vaz de Carvalho (3) (1) Instituto de Etnomusicologia, Música e Dança, ... more V. Debut , J. Antunes , P. Vaz de Carvalho (3) (1) Instituto de Etnomusicologia, Música e Dança, Faculdade de Ciências Sociais e Humanas, Universidade Nova de Lisboa, 1069-061 Lisboa, Portugal [email protected] (2) Centro de Ciências e Tecnologias Nucleares, Instituto Superior Técnico, Universidade de Lisboa, Estrada Nacional 10, Km 139.7, 2695-066 Bobadela LRS, Portugal [email protected] (3) Instituto de Etnomusicologia Centro de Estudo de Música e Dança, Universidade de Aveiro, 3810-193, Aveiro, Portugal [email protected]
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Papers by José Manuel Antunes