Speckle mechanism in holographic optical coherence imaging

Title from PDF of title page (University of Missouri--Columbia, viewed on Feb 15, 2010).The entire thesis text is included in the research.pdf file; the official abstract appears in the short.pdf file; a non-technical public abstract appears in the public.pdf file.Dissertation advisor: Dr. Ping Yu.Vita.Ph. D. University of Missouri--Columbia 2009.This thesis gives a systematical study of speckles based on holographic optical coherence imaging (OCI) system. The first studies on speckle statistics in holographic OCI are provided. The new speckle statistics consider the combination of holographic speckle and photorefractive effects, and is used to optimize the holographic diffraction efficiency and coherent image contrast for biomedical imaging applications. With a moving grating technique, speckle noises in holographic OCI are successfully suppressed based on a speckle averaging in the CCD camera. Also, the system longitudinal resolution degradation depends on the mean free path (concentration) of the suspensions. Besides, holographic optical imaging using two wave mixing is explored with acceptable image quality due to higher diffraction efficiency than that of conventional four-wave mixing in the photorefractive materials.Includes bibliographical reference

Riesz transform on manifolds with ends of different volume growth for 1<p<21<p<2

Let $M_1$, $\cdots$, $M_\ell$ be complete, connected and non-collapsed manifolds of the same dimension, where $2\le \ell\in\mathbb{N}$, and suppose that each $M_i$ satisfies a doubling condition and a Gaussian upper bound for the heat kernel. If each manifold $M_i$ has volume growth either bigger than two or equal to two, then we show that the Riesz transform \nabla \L^{-1/2} is bounded on $L^p(M)$ for each $1<p<2$ on the gluing manifold $M=M_1\#M_2\#\cdots \# M_\ell$.Comment: 38p

The Effect of Negative Learning-related Emotions on Higher Education Faculty\u27s Online Professional Development

This research examined how faculty\u27s negative learning-related emotions were associated with their technology acceptance and learning engagement in online professional development

Resilient Wide-Area Damping Control Using GrHDP to Tolerate Communication Failures

This paper proposes a goal representation heuristic dynamic programming (GrHDP)-based resilient wide-area damping controller (WADC) for voltage source converter high voltage direct current (VSC-HVDC) employing redundant wide-area signals as input signals to tolerate communication failure. A supervisory fuzzy logic module is proposed and added in the resilient WADC to adjust the learning rate of GrHDP online when encountering communication failure. Moreover, the resilient WADC does not need the accurate model of the power system and has the adaptability to the variation of operation conditions and communication failures. Case studies are conducted in a 10-machine 39-bus system with one VSC-HVDC transmission line. Simulation results show that the resilient WADC can counteract the negative impact of communication failures on control performance under a wide range of system operating conditions

Boundedness of Parametrized Littlewood-Paley Operators with Nondoubling Measures

Let μ be a nonnegative Radon measure on â„Âd which only satisfies the following growth condition that there exists a positive constant C such that μ(B(x,r))≤Crn for all x∈â„Âd, r>0 and some fixed n∈(0,d]. In this paper, the authors prove that for suitable indexes àand λ, the parametrized gλ∗ function ℳλ∗,àis bounded on Lp(μ) for p∈[2,∞) with the assumption that the kernel of the operator ℳλ∗,àsatisfies some Hörmander-type condition, and is bounded from L1(μ) into weak L1(μ) with the assumption that the kernel satisfies certain slightly stronger Hörmander-type condition. As a corollary, ℳλ∗,àwith the kernel satisfying the above stronger Hörmander-type condition is bounded on Lp(μ) for p∈(1,2). Moreover, the authors prove that for suitable indexes àand λ,ℳλ∗,àis bounded from L∞(μ) into RBLO(μ) (the space of regular bounded lower oscillation functions) if the kernel satisfies the Hörmander-type condition, and from the Hardy space H1(μ) into L1(μ) if the kernel satisfies the above stronger Hörmander-type condition. The corresponding properties for the parametrized area integral ℳSàare also established in this paper