This thesis reports on research into the applicability of intelligent agents in the airline scheduling environment. The methodology employed was to look at intelligent agent research and then, based on this, to build models that can be used to solve some of the airline scheduling problems. The following was done: · An agent-based model was developed that can assist airline schedulers in the maintenance of a disrupted schedule. The agent model consists of a hybrid approach combining elements of machine learning and expert systems. · A multiagent model was developed that can generate a profitable and flyable schedule. The multiagent model developed extends the traditional control structures of the hierarchical agent organisation to a matrix structure. This new model can be extended to any problem domain that deals with resource allocation and capacity management. To guide the thinking behind this research, a few questions were posed regarding the problem to be solved: Q1. Can intelligent agents play a role in the airline industry, with specific focus on the scheduling creation and maintenance process? Q2. What will the design of the agent models be if the scheduling needs of an airline have to be addressed? Q3. If the models as envisioned in question 2 can be created, what will the practical implications be? At a conceptual level the research produced three results: R1. No references were found to multiagent technology in the production or maintenance of airline schedules. This theoretical research into agent systems shows that there is applicability in the scheduling environment, with specific reference to schedule maintenance and generation. R2. An agent model was created that combines declarative knowledge with empirical learning to assist human schedulers in the day-to-day maintenanceof the schedule. Multiple solutions to a scheduling problem are generated by the agent using embedded scheduling rules. The agent then uses the Qlearning algorithm to learn the preferences of the human scheduler. This approach combines the best of expert systems and machine learning. To solve the problem of schedule generation, a multiagent system with a matrix governance model was introduced. Aircraft and airports were modelled as buying and selling agents. The business manager agent that assigns individual aircrafts to specific routes was defined. This was accomplished by matching individual aircraft capacity to origin-destination demand. The agent model was then expanded to show how the inclusion of a resource manager agent can handle system capacity management. This is a matrix governance model, as an aircraft agent is managed by a business manager agent, as well as by a resource manager agent. The initial results from the prototype show that this model can generate profitable and flyable schedules. The multiagent model developed extends the traditional hierarchical agent organisation to that of a matrix structure. The contract net protocol used for typical multiagent coordination was adapted to work in this new control structure. This new model can be extended to any problem domain that deals with resource allocation and capacity management. R3. A few airlines use expert systems to handle schedule disruptions. By introducing machine learning, a flexibility is achieved that is currently not available. The approach proposed for schedule generation is not guaranteed to provide optimal results like traditional operations research techniques, but it is useful for high-level analysis, long-term planning, new hub or alliance planning and research. It also has potential as a catalyst for integrated planning. Keywords: Multiagent systems, airline scheduling / Ehlers, E.M., Prof.
| Identifer | oai:union.ndltd.org:netd.ac.za/oai:union.ndltd.org:uj/uj:8654 |
| Date | 02 June 2008 |
| Creators | Langerman, Josef Jacobus |
| Source Sets | South African National ETD Portal |
| Detected Language | English |
| Type | Thesis |
Page generated in 0.0172 seconds