Four people are to receive the Academy’s Silver Medal for their contribution to British engineering and commercial development. They include  Dr Simon Gallimore  who is a renowned authority in compressor and turbine aerodynamics  Professor Lionel Tarassenko FREng  who has helped develop novel signal processing and pattern recognition techniques  Dr Ian McEwan  the inventor of a unique solution to pipeline leakage problems, and  Professor Andrew Blake FREng FRS  whose major technical achievements have been in visual segmentation and reconstruction, and in visual motion tracking.