Tools for Advanced Video Metadata Modeling

In this Thesis, we focus on problems in surveillance video analysis and propose advanced metadata modeling techniques to address them. First, we explore the problem of constructing a snapshot summary of people in a video sequence. We propose an algorithm based on the eigen-analysis of faces and present an evaluation of the method. Second, we present an algorithm to learn occlusion points in a scene using long observations of moving objects, provide an implementation and evaluate its performance. Third, to address the problem of availability and storage of surveillance videos, we propose a novel methodology to simulate video metadata. The technique is completely automated and can generate metadata for any scenario with minimal user interaction. Finally, a threat detection model using activity analysis and trajectory data of moving objects is proposed and implemented. The collection of tools presented in this Thesis provides a basis for higher level video analysis algorithms

Mesoscale Models for Stacking Faults, Deformation Twins and Martensitic Transformations: Linking Atomistics to Continuum

131 p.Thesis (Ph.D.)--University of Illinois at Urbana-Champaign, 2007.Finally, we extend the present work to martensitic transformations and determine the energy pathway for B2→B19 transformation in NiTi. Based on our ab initio DFT calculations, we propose a combined distortion-shuffle pathway for B2→B19 transformation in NiTi. Our results indicate that in NiTi, a barrier of 0.48 mRyd/atom (relative to B2 phase) must be overcome to transform the parent B2 into orthorhombic B19 phase.U of I OnlyRestricted to the U of I community idenfinitely during batch ingest of legacy ETD

Mesoscale Models for Stacking Faults, Deformation Twins and Martensitic Transformations: Linking Atomistics to Continuum

131 p.Thesis (Ph.D.)--University of Illinois at Urbana-Champaign, 2007.Finally, we extend the present work to martensitic transformations and determine the energy pathway for B2→B19 transformation in NiTi. Based on our ab initio DFT calculations, we propose a combined distortion-shuffle pathway for B2→B19 transformation in NiTi. Our results indicate that in NiTi, a barrier of 0.48 mRyd/atom (relative to B2 phase) must be overcome to transform the parent B2 into orthorhombic B19 phase.U of I OnlyRestricted to the U of I community idenfinitely during batch ingest of legacy ETD

Quantization of β-Fermi-Pasta-Ulam lattice with nearest and next-nearest neighbor interactions

We quantize the β-Fermi-Pasta-Ulam (FPU) model with nearest and next-nearest neighbour interactions using a number conserving approxima-tion and a numerical exact diagonalization method. Our numerical mean field bi-phonon spectrum shows excellent agreement with the analytic mean field results of Ivic ́ and Tsironis ((2006) Physica D 216 200), except for the wave vector at the midpoint of the Brillouin zone. We then relax the mean field approximation and calculate the eigenvalue spectrum of the full Hamil-tonian. We show the existence of multi-phonon bound states and analyze the properties of these states as the system parameters vary. From the calcula-tion of the spatial correlation function we then show that these multi-phonon bound states are particle like states with finite spatial correlation. Accord-ingly we identify these multi-phonon bound states as the quantum equiva-lent of the breather solutions of the corresponding classical FPU model. The four-phonon spectrum of the system is then obtained and its properties are studied. We then generalize the study to an extended range interaction and consider the quantization of the β-FPU model with next-nearest-neighbour interactions. We analyze the effect of the next-nearest-neighbour interactions on the eigenvalue spectrum and the correlation functions of the system. 1

A novel approach to fabricating a nanotwinned surface on a ternary nickel alloy

Deformation nanotwinning is performed using molecular dynamics (MD) on a single crystal in a ternary nickel (Ni) alloy. Generalized embedded-atom method (EAM) potential functions are obtained for the ternary Ni alloy. The critical twinning stress is 4.48 GPa, calculated by the MD simulations. Detwinning, restoring and regenerating of nanotwins take place during the unloading process, contributing to the remaining of the ductility. According to the MD simulations, a novel approach is proposed to fabricating a nanotwinned surface using nanoindentation at room temperature. This is different from previous reports, in which high temperature, high pressure or chemical regents are employed