In this talk, Polya trees are introduced and properties are derived for the standard parameterization. The error terms in a standard regression model are assigned a mixture of Polya trees distribution constrained to have median zero and inference is obtained via the Metropolis algorithm. Several examples with real data demonstrate the utility of this model and favorable comparisons with other parametric and nonparametric approaches are made. Abstract Validation of control system performance is a common task in certification of aircraft and other vehicles. The closed loop control specifications often require a tolerance to various levels of white noise disturbance without disruption of the normal operation of the aircraft.
Recent specifications require a tolerance to bounded wind gusts without loss of stable performance.
Testing of control systems in the worst case bounded disturbance situation is the objective of the thesis research summarized here. It is shown in this thesis that the most stressful bounded disturbance for a linear stable second order system with numerator dynamics is of bang-bang type and should be realized in feedback form. To test the control system robustness and dynamics, a bounded disturbance is selected to maximize a severity index, usually time distance. A switch curve can be used to realize the disturbance in feedback form. The switch curve has a general analytic form for second order systems.