964 resultados para Matched labelling
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During the last years many researchers have been working on the active matching or on non-Foster matching networks for one- and two-port electrically small antennas (ESAs). A new parameter on the sensitivity of the two-port electrically small antenna when loaded with a non-F oster network is presented. This sensitivity analysis will allow us to choose what kind of antennas can be properly matched with non-Foster networks and their position in order to optimi ze the performance of the design. Then, a typical high Q two-port antenna will be harder to match over a broad bandwidth, since |S21| is very small and only agrees with |S11| over very small frequency bands, yielding very large sensitivity values. However, for these two-port antennas, if high levels of coupling can be engineered for a high Q multiple-port antenna, the return and insertion losses can be similar over larger bandwidths and, hence, the sensitivity can be kept low over larger bandwidths, enabling broader impedance matched bandwidths to be achieved, even for highly resonant antennas.
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Acknowledgements The work was in part funded by UK Medical Research Council project grant G0601253 to G.S.B. and R.W.B.
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Objective: To assess the net 5 year effects of intervention of a community based demonstration project, the Heartbeat Wales programme, on modifiable behavioural risks for prevention of cardiovascular disease.
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The Elliptical Scanning Algorithm is an effective method to individually detect and label the projected rings. It consecutively defines an elliptical annulus of one pixel wide which grows pixel by pixel and sweeps the image, from centre to periphery, until it detects and labels each whole ring. In a way, it works like a snake-annealing algorithm. Active contour models (snakes) are energy-minimising curves that deform to fit image features. Elliptical Scanning Algorithm changes its geometry in order to label reflected rings.
