Placement of Piezoelectric Laminate Actuator for Active Structural Acoustic Control

Conference (2004)

Case studies in measurement of random incidence scattering coefficients

in Acta Acustica United With Acustica (2004), 90(5, SEP-OCT), 858-867

In this work measurements of random-incidence scattering coefficients in three laboratories are compared. The sample geometry is sinusoidal. These surfaces are geometrically identical, but they were ... [more ▼]

In this work measurements of random-incidence scattering coefficients in three laboratories are compared. The sample geometry is sinusoidal. These surfaces are geometrically identical, but they were constructed in different scales. So far, measurements of this kind were performed only in scale models. Using turntables in real sample size was hardly considered possible. One result of general importance is that measurements are indeed possible in real-scale reverberation rooms with turntables of 3 m diameter. There are only small differences between the real-scale and model-scale results. Some variations of the standard procedure were tested and the uncertainties identified: mounting of the sample, connection or sealing between sample and base plate, way of rotating the sample, air absorption and time variances. The results presented can be regarded as guidelines for application of ISO/DIS 17497-1. [less ▲]

Optimal design of outdoor lighting systems by genetic algorithms - Discussion

in Lighting Research & Technology (2003), 35(3), 278-280

Calculation of the scattering coefficient of a sine-shaped surface by solving the Helmholtz integral

in Proceedings of the Institute of Acoustics (2003), 25(5), 67-74

Comparison of different impulse response measurement techniques

in Journal of the Audio Engineering Society (2002), 50(4), 249-262

The impulse response of an acoustical space or transducer is one of its most important characterizations. In order to perform the measurement of their impulse responses, four of the most suitable methods ... [more ▼]

The impulse response of an acoustical space or transducer is one of its most important characterizations. In order to perform the measurement of their impulse responses, four of the most suitable methods are compared: MLS (maximum-length sequence), IRS (inverse repeated sequence), time-stretched pulses, and SineSweep. These methods have already been described in the literature. Nevertheless, the choice of one of them depending on the measurement conditions is critical. Therefore an extensive comparison has been realized. This comparison was done through the implementation and realization of a complete, fast, reliable, and cheap measurement system. Finally, a conclusion for the use of each method according to the principal measurement conditions is presented. It is shown that in the presence of nonwhite noise, the MLS and IRS techniques seem to be more accurate. On the contrary, in quiet environments the logarithmic SineSweep method seems to be the most appropriate. [less ▲]

Practical aspects of the ISO procedure for measuring the scattering coefficient in a real-scale experiment

Conference (2002)

Study of the influence of coloured road surfaces on the efficiency of road lighting installations

in Proceedings of the 9th Lux Europa Congress (2001)

Determination of the scattering coefficient of random rough diffusing surfaces for room acoustics applications

in Acta Acustica United with Acustica (2001), 87

L'éclairage : à nouveaux critères, nouveaux outils de mesure, de calcul et de simulation

in Revue de l'Electricité et de l'Electronique (2000), 7

Présentation de la nouvelle chaire des "techniques du son et de l'image" de l'université de Liège

Article for general public (2000)