O Portal C Smico De Rion

Decision Models for the Procurement of Subsidised Air Services

Small communities or remote regions are usually ignored by airlines because they have insufficient passenger demand and the air services to and from these regions are unprofitable. Free market conditions would lead to the lack of air connectivity to and from remote regions, hence transportation authorities intervene by procuring air services to guarantee improved accessibility for these regions. The procurement of air services is done through subsidy schemes where the transportation authorities pay subsidies to airlines that provide these air services along the routes to and from remote regions. These routes are commonly referred to as subsidised routes. The procurement of subsidised air services (subsidised routes) involves two major tasks—the selection of routes to subsidise and the selection of airlines to serve these routes. These are the focus of this thesis. The overall aim of this thesis is to design decision support models that can be used by transportation authorities to select the routes to subsidise and to select airlines to serve these routes. First, we develop an optimisation model that selects the routes to be subsidised, by maximising the number of people that can reach a given destination under different accessibility criteria subject to a budget. The model is capable of handling multiple accessibility criteria. As input to this model, we develop a novel method for estimating the subsidies required for non-existing subsidised routes. Second, we develop an auction framework to provide decision support to transportation authorities when designing auctions for the procurement of subsidised air services. The auction framework has three steps: auction definition by the transportation authority, bid preparation by the bidding airlines, and winner determination by the transportation authority. We develop two optimisation models as part of the auction framework, a winner-determination model for selecting the bids with the minimum subsidies, and a bid preparation model that replicates the airline’s behaviour when preparing bids for subsidised routes. The bid preparation model has an objective of minimising subsidies subject to a minimum profit threshold. We additionally propose models to estimate the appropriate demand and the route-operation cost for subsidised routes, which are needed as input to the bid preparation model. We demonstrate the usefulness of the two decision support models using the Public Service Obligation (PSO) network of subsidised routes in Sweden. The results suggest that the optimisation model can be used to select a new network of subsidised routes with improved accessibility to given destinations (e.g., the capital and an international airport) at a lower subsidy cost than the current network of subsidised routes. Having a requirement on the maximum airfare but not the minimum number of flights provides a good trade-off between the current restrictive setup with requirements on both the minimum number of flights and the maximum airfare, and a setup of the tendering process with no restrictions.

Waiting for the End of the World?

Waiting for the End of the World? addresses the archaeological, architectural, historical and geological evidence for natural disasters in the Middle Ages between the 11th and 16th centuries. This volume adopts a fresh interdisciplinary approach to explore the many ways in which environmental hazards affected European populations and, in turn, how medieval communities coped and responded to short- and long-term consequences. Three sections, which focus on geotectonic hazards (Part I), severe storms and hydrological hazards (Part II) and biophysical hazards (Part III), draw together 18 papers of the latest research while additional detail is provided in a catalogue of the 20 most significant disasters to have affected Europe during the period. These include earthquakes, landslides, tsunamis, storms, floods and outbreaks of infectious diseases. Spanning Europe, from the British Isles to Italy and from the Canary Islands to Cyprus, these contributions will be of interest to earth scientists, geographers, historians, sociologists, anthropologists and climatologists, but are also relevant to students and non-specialist readers interested in medieval archaeology and history, as well as those studying human geography and disaster studies. Despite a different set of beliefs relating to the natural world and protection against environmental hazards, the evidence suggests that medieval communities frequently adopted a surprisingly ‘modern’, well-informed and practically minded outlook.

North border. 3 v