Browsing by Author "Rivers, Catherine Margaret"

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Coordination in vehicle routing : a thesis presented in partial fulfilment of the requirements for the degree of Doctor of Philosophy in Operations Research at Massey University, Palmerston North, New Zealand
(Massey University, 2002) Rivers, Catherine Margaret
Coordination involves the re-deployment of payload between depot and customer, and includes split deliveries, load transfers and load swapping, facilitated by the establishment of coordination sites at strategic locations. Real-world coordination includes mid-air refuelling, the use of temporary replenishment sites, trailers left for later uplift by their towing vehicles, bulk re-suppliers travelling to field operatives, fleet re-supply, and couriers swapping loads on the side of the road. This thesis models the coordination process and investigates the basic types of coordination in single depot, pure delivery systems in both the Euclidean plane and the rectilinear grid network. Strategies are developed for dealing with dynamic situations in the rectilinear grid, which are based on the pre-processing of scenarios in order that dispatchers may select a suitable response from an existing selection at the time that dynamic values are revealed. In addition, a procedure is suggested that reduces the number of edges and vertices of a rectilinear grid to those that may be useful within a coordination hull.
Numerical and approximate solutions to problems in spontaneous ignition : a thesis presented in partial fulfilment of the requirements for the degree of Master of Philosophy in Mathematics at Massey University
(Massey University, 1994) Rivers, Catherine Margaret
This thesis considers the subject of time-independent spontaneous ignition of materials of arbitrary shape. Chapter One reviews the major advances up to the work ofD.A.Frank-Kamenetskii. Chapter Two discusses the modern, Gray Wake, formulation of the problem. In Chapter Three, ignition in the class A shapes is approximated by a numerical finite differences method. The same method is applied to some non-class A geometries. Solutions to the Gray Wake formulation for ignition in the infinite slab geometry are sought in Chapter Four by approximating the internal energy gradient by the maximum internal energy and by the average internal energy. Chapter Five considers an industrial application of the spontaneous ignition of moist powder.