A qualitative temporal information system for process control

A general system is presented in this paper which supports the expression of relative temporal knowledge in process control and management. This system allows knowledge of Allen's temporal relations over time elements, which may be both intervals and points. The objectives and characteristics of two major temporal attributes, i.e. ‘transaction time’ and ‘valid time’, are described. A graphical representation for the temporal network is presented, and inference over the network may be made by means of a consistency checker in terms of the graphical representation. An illustrative example of the system as applied to process control and management is provided.

Art always at heart

The Art Workers Guild, brother body to the SPAB and once presided over by William Morris and his followers, is 125 years old this year. Alan Powers looks back over its history, and sheds light on the characters and common bonds between the two bodies – while present Brothers of the Guild are pictured at work by photographer Lara Platman for new book to mark the event.