Abstract: In a substitutional media system, one of a set of media items is selected at a programme receiver for output within a predefined programming slot, based on profile data available at the receiver. Sets of the media items are scheduled to slots according to one or more constraints pertaining to that slot and/or to media items scheduled to other slots. The receiver may select a media item for output in a slot by resolving constraints with media items scheduled to other slots, or selected for output in other slots.

Abstract: A method and apparatus (1) for machining a semiconductor or ceramic workpiece (32) causes a portion of the workpiece to undergo high pressure phase transformation to form a high pressure phase transformation portion which has altered optical properties from the remainder of the workpiece. A laser is irradiated on the high pressure transformation portion to heat the high pressure transformation portion and cause it to soften and then the workpiece is plastically deformed, at smaller loads and forces, along the softened portion in order to accomplish the machining of the workpiece with a machining tool (21).