C.a.d. in the Br!tish Computer Society
The annual general meeting of the computer aided design group of the British Computer Society was held on the 25th July. The four meetings held last year included talks on p.c.b. layout, i.e. mark design, mechanical design and drafting and a visit to Cambridge University, the last event being best attended.
The aims of the group were seen as promoting technical discussion between workers in c.a.d, and the construction of a bridge between industry and universities. Recent setbacks in c.a.d. expansion because of the 'initially enthusiastic, now loss of confidence' attitude prevalent in some industries were being superseded by a new conference.
A new chairman, Mr M. Sabin of B.A.C. Weybridge, a secretary and the committee were elected, after which Mr Davies, of the Transport and Road Research Laboratory, lectured ;nterestingly and amusingly on 'optimization techniques used in the location of a new road'.
Mr Davies began with the historical background to road building, which led on to modern road location and construction. General criteria and conditions for motorway design were laid down; for example, gradient and speed limitations.
Objectives in new-road siting are an alignment best suited for traffic, the shortest route possible and minimum construction costs. Some factors affecting these are drainage, bridges and earthworks.
The optimization problem in road design is a very complex one. Massachusetts Institute of Technology were the first to attempt optimization of alignment variables, before 1960, and several countries other than America have since been active in this field. The Transport and Road Research Laboratory began optimization work in 1966 and now have several programs for dealing with vertical alignment and other aids to the contractor. Their vertical alignment program uses a direct search technique, which, although inefficient in purely optimization terms, does not demand a pre-definition of the job as do other methods.
Mr Davies answered questions and showed a short film of the application