Directivity for scalar radiation

Horizontal Directivity of Pipa Radiation

Pipa is one of the most important Chinese traditional plucked instruments, but its directivity has never been measured systematically. In western, directivity of loudness for western instruments is deeply researched through analysis of sound pressure level, whereas the directivity of timbre is seldom studied. In this paper, a new method for directivity of timbre was proposed, and horizontal dir...

Tonehole Radiation Directivity: A Comparison of Theory to Measurements

Measurements have been conducted in an anechoic chamber for comparison to current linear acoustic theory for radiation directivity from a cylindrical pipe with toneholes. Time-delay spectrometry using an exponentially swept sine signal was employed to determine impulse responses at points external to the experimental air column. This technique is effective in clearly isolating nonlinear artifac...

The directivity of the sound radiation from panels and openings.

This paper presents a method for calculating the directivity of the radiation of sound from a panel or opening, whose vibration is forced by the incidence of sound from the other side. The directivity of the radiation depends on the angular distribution of the incident sound energy in the room or duct in whose wall or end the panel or opening occurs. The angular distribution of the incident sou...

A radiation scalar for numerical relativity.

This Letter describes a scalar curvature invariant for general relativity with a certain, distinctive feature. While many such invariants exist, this one vanishes in regions of space-time which can be said unambiguously to contain no gravitational radiation. In more general regions which incontrovertibly support nontrivial radiation fields, it can be used to extract local, coordinate-independen...

Directional Waveform Deformation and Directivity of Transient Acoustic Wave Radiation