Now showing items 41-60 of 152

• #### Feedback Stabilisation of Locally Controllable Systems ﻿

(2012-09-25)
Controllability and stabilisability are two fundamental properties of control systems and it is intuitively appealing to conjecture that the former should imply the latter; especially so when the state of a control system ...
• #### Filter Stability, Observability and Robustness for Partially Observed Stochastic Dynamical Systems ﻿

Filter stability refers to the correction of an incorrectly initialized filter for a partially observed stochastic dynamical system with increasing measurements. In this thesis, we study the filter stability problem, develop ...
• #### Forecasting and Non-Stationarity of Surgical Demand Time Series ﻿

(2014-02-04)
Surgical scheduling is complicated by naturally occurring, and human-induced variability in the demand for surgical services. We used time series methods to detect, model and forecast these behaviors in surgical demand ...
• #### A Framework for the Meta-Analysis of Survey Data ﻿

(2011-12-06)
The research outlined in this thesis covers various different statistical issues relating to meta-analysis of survey data. These issues include the creation of an original comprehensive methodological framework for combining ...
• #### Generalization of Ruderman's Problem to Imaginary Quadratic Fields ﻿

(2012-04-13)
In 1974, H. Ruderman posed the following question: If $(2^m-2^n)|(3^m-3^n)$, then does it follow that $(2^m-2^n)|(x^m-x^n)$ for every integer $x$? This problem is still open. However, in 2011, M. R. Murty and V. K. Murty ...
• #### Geodesic reduction via frame bundle geometry ﻿

(2007-07-25)
Reduction theory for systems with symmetry deals with the problem of understanding dynamics on a manifold with an action of a Lie group. In geometric mechanics, this problem can be formulated in the Lagrangian, Hamiltonian ...
• #### A Geometric Approach to Energy Shaping ﻿

(2009-09-02)
In this thesis is initiated a more systematic geometric exploration of energy shaping. Most of the previous results have been dealt wih particular cases and neither the existence nor the space of solutions has been discussed ...
• #### Geometric Jacobian Linearization ﻿

(2007-12-21)
For control systems that evolve on Euclidean spaces, Jacobian linearization is a common technique in many control applications, analysis, and controller design methodologies. However, the standard linearization method ...
• #### Geometric local controllability: second-order conditions ﻿

(2002)
In a geometric point of view, a nonlinear control system, affine in the controls, is thought of as an affine subbundle of the tangent bundle of the state space. In deriving conditions for local controllability from ...
• #### Geometric sliding mode control: The linear and linearised theory ﻿

(2002)
The idea of sliding mode control for stabilisation is investigated to determine its geometric features. A geometric definition is provided for a sliding submanifold, and for various properties of a sliding submanifold. Sliding ...
• #### Geometry of Dirac Operators ﻿

(2016-07-05)
Let $M$ be a compact, oriented, even dimensional Riemannian manifold and let $S$ be a Clifford bundle over $M$ with Dirac operator $D$. Then \[ \textsc{Atiyah Singer: } \quad \text{Ind } \mathsf{D}= \int_M ...
• #### The geometry of the Gibbs-Appell equations and Gauss's Principle of Least Constraint ﻿

(1995)
We present a generalisation of the Gibbs-Appell equations which is valid for general Lagrangians. The general form of the Gibbs-Appell equations is shown to be valid in the case when constraints and external forces ...
• #### The geometry of the maximum principle for affine connection control systems ﻿

(2000)
The maximum principle of Pontryagin is applied to systems where the drift vector field is the geodesic spray corresponding to an affine connection. The result is a second-order differential equation whose right-hand side ...
• #### Global Fluctuations of Random Matrices and the Second-Order Cauchy Transform ﻿

In this thesis we study the global fluctuations of random matrices (i.e., the covariance of two traces) from a second-order free probability perspective, putting a particular emphasis on block Gaussian matrices. Our main ...
• #### Group structures in a class of control systems ﻿

(1992)
We investigate two classes of control systems, one of Brockett and one of Murray and Sastry. We are able to show that these two systems may be formulated in the language of principle fibre bundles. Controllability of ...
• #### Hall conditions for edge-weighted bipartite graphs ﻿

(2010-07-28)
A weighted variant of Hall's condition for the existence of matchings is shown to be equivalent to the existence of a matching in a lexicographic product. This is used to introduce characterizations of those bipartite ...
• #### Hamiltonian Systems of Hydrodynamic Type ﻿

(2010-12-23)
We study the Hamiltonian structure of an important class of nonlinear partial differential equations: the so-called systems of hydrodynamic type, which are first-order in tempo-spatial variables, and quasi-linear. Chapters ...
• #### High-order variations for families of vector fields ﻿

(2002)
Sufficient conditions involving Lie brackets of arbitrarily high-order are obtained for local controllability of families of vector fields. After providing a general framework for the generation of high-order ...
• #### High-Q Spectral Peaks and Nonstationarity in the Deep Ocean Infragravity Wave Band: Tidal Harmonics and Solar Normal Modes ﻿

(Wiley, 2019-02-20)
Infragravity waves have received the least study of any class of waves in the deep ocean. This paper analyzes a 389-day-long deep ocean pressure record from the Hawaii Ocean Mixing Experiment for the presence of narrowband ...
• #### Higher rank sieves and applications ﻿

(2016-04-25)
This thesis focuses on some of the key sieve theoretic ideas behind recent progress on bounded gaps between the primes. One such idea is the notion of higher rank sieve weights, first proposed by Atle Selberg and applied ...