OCR MEI D2 2011 June — Question 2

Exam BoardOCR MEI
ModuleD2 (Decision Mathematics 2)
Year2011
SessionJune
TopicTravelling Salesman

2 A government has just created a new ministry, the Ministry of Administrative Affairs. The ministry is to have four departments:
the Administration
the Bureaucracy
the Certification Service
the Duplication Section.
Each of these departments is to be established in a separate office on one of four existing sites. The diagram shows the direct journey times in minutes between these four sites.
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  1. Use Floyd's algorithm to find the shortest journey times between the four office sites.
  2. Draw a network showing your shortest times.
  3. Use appropriate algorithms to find upper and lower bounds for the optimum solution to the Travelling Salesperson Problem in the original network, briefly explaining the steps taken.
  4. A van is to be organised to deliver bundles of paperwork between the departments. Why might the optimum solution to the TSP be useful in planning this, and why might it not be?
  5. Journeys to locations 2 and 3, from locations 1 and 4, are subject to a congestion charge which is equivalent in costing terms to 15 minutes of journey time. What sort of network would be needed to model this?