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Type of Document Dissertation Author Ortiz, Norma Author's Email Address ortiz@math.lsu.edu URN etd-02082005-130556 Title Dynamical Systems with Time Delay Degree Doctor of Philosophy (Ph.D.) Department Mathematics Advisory Committee
Advisor Name Title Peter R. Wolenski Committee Chair Frank Neubrander Committee Member James Madden Committee Member Michael A. Malisoff Committee Member Richard A. Litherland Committee Member Guoxiang Gu Dean's Representative Keywords
- problem of Bolza
- necessary conditions
- calculus of variations
- control theory
- differential inclusion
- delay
- neutral systems
Date of Defense 2005-01-20 Availability unrestricted Abstract In this dissertation, we study necessary conditions and weak invariance properties of dynamical systems with time delay. A number of results have been obtained recently that refine necessary conditions of optimal solutions for nonsmooth dynamical systems without time delay. In this dissertation, we examine the extension of some of these results to problems with time delay. In particular, we study the generalized problem of Bolza with the addition of delay in the state and velocity variables and refer to this problem as the Neutral Problem of Bolza. We consider the relationship between the generalized problem of Bolza with time delay and control systems, establish existence of solutions for the Neutral Problem of Bolza, and use a ``decoupling' technique introduced by Clarke to derive necessary conditions of Hamiltonian and Euler-Lagrange type for this problem. We also apply the same methods to the generalized problem of Bolza with time delay in the state variable only and compare the results obtained in this case with the results obtained in the neutral case. Furthermore, we study the system (S,F) involving a closed set S and a delayed autonomous multifunction F(x(t),x(t-Delta)). Under suitable hypotheses, we provide a characterization of weak invariant properties for F in terms of the lower hamiltonian.Files
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