EXPERIMENTAL STUDIES FOR DEVELOPMENT HIGH-POWER AUDIO SPEAKER DEVICES PERFORMANCE USING PERMANENT NdFeB MAGNETS SPECIAL TECHNOLOGY

In this paper the authors shows the research made for improving high-power audio speaker devices performance using permanent NdFeB magnets special technology. Magnetic losses inside these audio devices are due to mechanical system frictions and to thermal effect of Joules eddy currents. In this regard, by special technology, were made conical surfaces at top plate and center pin. Analysing results obtained by modelling the magnetic circuit finite element method using electronic software package,was measured increase efficiency by over 10 %, from 1,136T to13T

An Image-Based Inexpensive 3D Scanner

© 2003 World Scientific Publishing Company.An image-based model reconstruction system is described in this paper where real images of a rigid object acquired under a simple but controlled environment are used to recover its three dimensional geometry and its surface texture. Based on a multi-image calibration method, an algorithm to extract the rotation axis of a turn-table has been developed. Furthermore, this algorithm can be extended to estimate robustly the initial bounding volume of the object to be modeled. The coarse volume obtained is then carved using a stereo correction method which removes the disadvantages of silhouette-based reconstruction by photoconsistency. The concept of surface particles is adapted in order to extract a texture map for the model. Some existing metrics are used to measure the quality of the reconstructed models