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This paper presents a computer vision based virtual learning environment for teaching communicative hand gestures used in Sign Language. A virtual learning environment was developed to demonstrate signs to the user. The system then gives real time feedback to the user on their performance of the demonstrated sign. Gesture features are extracted from a standard web-cam video stream and shape and trajectory matching techniques are applied to these features to determine the feedback given to the user.

-The Goertzel Algorithm provides an efficient mechanism for tone detection in signal processing. However, on Wireless Sensor Network nodes, there is often not sufficient processing power to implement this using floating-point arithmetic, so fixed-point implementations are used. In this paper we compare the quality of the results for a typical audio application with different resolutions of fixed-point support using MATLAB. We also provide performance figures based on implementing this on a representative sensor node platform. Our results show that, for this application-space, 16-bit fixed-point arithmetic provides the best tradeoff of accuracy against performance. No previous work has addressed this specific aspect of implementating the Goertzel algorithm.

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The Modal Distribution (MD) is a time-frequency distribution specifically designed to model the quasi-harmonic, multisinusoidal, nature of music signals and belongs to the Cohen general class of time-frequency distributions. Signal synthesis from bilinear time-frequency representations such as the Wigner distribution has been based on methods which exploit an outer-product interpretation of these distributions [1,2]. Methods of synthesis from the MD based on a sinusoidalanalysis-synthesis procedure using estimates of instantaneous frequency and amplitude only have been investigated in [3,4,5]. However, the modal distribution is basically a subsampled version of the smoothed pseudo Wigner distribution and thus does not lend itself easily to direct inversion such as in the outer product methods mentioned above. Furthermore, the modal distribution is real, and the above sinusoidal-analysissynthesis methods rely on phase estimated as the integral of instantaneous frequency. In this paper, we show that in some cases, this synthesis results in a roughness or phasiness in the synthesized signal and demonstrate that using minimum phase derived from the magnitude spectrum of the distribution produces a timbre closer to the original in the case of certain brass sounds. Suggestions for future work are also given.

Online digital music libraries have become important repositories for music for all enthusiasts of Irish traditional music. These libraries have certainly facilitated the discovery of new material and enabled extensive exploration of musical variations on wellknown favorites. Current web interfaces to these repositories, offer a combination of text and notation-based information as well as providing audio and midi listening formats. However, these interfaces could take advantage of more recently available technologies offering graph-based, interactive, visual displays and more useful data analytic content. Drawing on the state-of the-art data visualization web libraries, the objective of this work is to present a prototype of a new digital library for Irish traditional music. The design and architecture is detailed using standard Unified Modelling Language (UML) notation. Evaluation is carried out by a usability survey to determine the effectiveness of the enhancements.