The Archive of Modern American Warfare: Preserving Veterans\u27 History in the Digital Age

For over 26 years, the Vietnam Center and Archive at Texas Tech University has worked to preserve the history of Vietnam War veterans and has amassed the largest collection of Vietnam War records outside the National Archives. Now, the Center hopes to do the same thing for veterans of the modern wars with a new project known as the Archive of Modern American Warfare (AMAW). The AMAW collects and preserves records from veterans of military conflicts that occurred after 1975, with a particular focus on the Iraq and Afghanistan conflicts. Because of the nature of records being produced in the modern era, the AMAW is primarily a digital archive that collects born digital records such as digital photographs, digital videos, emails, text messages, and digital documents. These materials will be made available to researchers through an online portal that is currently under construction. Andrew Hinton, archivist with the AMAW, presents a case study of the Vietnam Center’s early work to build an open educational resource for the study of modern American military history

Application of optical single-sideband laser in Raman atom interferometry

A frequency doubled I/Q modulator based optical single-sideband (OSSB) laser system is demonstrated for atomic physics research, specifically for atom interferometry where the presence of additional sidebands causes parasitic transitions. The performance of the OSSB technique and the spectrum after second harmonic generation are measured and analyzed. The additional sidebands are removed with better than 20 dB suppression, and the influence of parasitic transitions upon stimulated Raman transitions at varying spatial positions is shown to be removed beneath experimental noise. This technique will facilitate the development of compact atom interferometry based sensors with improved accuracy and reduced complexity

Automatic laser shutdown implications for all optical data networks

Generalized multiprotocol label switching (GMPLS), optical packet, and burst-switched networks in which the synchronous digital hierarchy/synchronous optical network (SDH/SONET) layer is removed may be rendered nonfunctional because the current standard for triggering Automatic Power Reduction (APR) cannot distinguish between a fiber that has been de-energized and a fiber failure. If this standard is applied, without modification, the likelihood of unnecessary amplifier shutdown in optical networks is significant. These shutdown events may impact large regions of the network and render optical links inoperable. To avoid unnecessary amplifier shutdown, amendments to the current operation of APR are suggested

Supervised learning methods for association detection, biomarker discovery, and pattern recognition in compositional omics data

Rapid advances and reduced cost in high throughput sequencing (HTS) technologies have enabled widespread profiling of microbial metagenomes and microbiomes in humans to better understand associations between microbial communities and disease. Data generated using these technologies are vast, high-dimensional, and nuanced, including limitations in instrument sequencing capacities and measurements that are inherently relative rather than absolute. Unlike absolute measurements, these relative counts — referred to as compositional data — require special methods for analysis and interpretation. Unfortunately, compositional data methodology are esoteric and generally not well adapted to high throughput sequencing data. Because of this, HTS data are often analyzed with traditional statistical methods that do not properly account for the underlying compositional sample space. This practice may result in spurious associations being reported which may limit study-to-study generalizations and reproducibility. In this thesis, building on existing literature in compositional data analysis and feature selection methodology, we develop a novel statistical association test and a powerful machine learning framework using robust pairwise logratios. Additionally, for each method, we developed freely available (GitHub) R packages (SelEnergyPermR \& DiCoVarML) with functions to perform the core analysis of each method. In the first chapter we provide a basic overview of compositional data and its connection to HTS data. In the second chapter, we present the SelEnergyPerm method for detecting sparse associations in high dimensional metagenomic data. In the third chapter, building on the concept of differential compositional variation proposed in SelEnergyPerm, we present the DiCoVarML framework for supervised classification and biomarker discovery. In the final chapter, we apply the SelEnergyPerm method to test for an association between toxicant exposures and the composition of microbial communities in the nasal passage. Using a parsimonious logratio signature detected by SelEnergyPerm, we then perform integrative analysis, where we explore the connection between nasal microbiome dsybiosis and immune mediator expression in nasal lavage fluid.Doctor of Philosoph

Development of a transportable cold atom gradiometer

This work describes the technology developed for the transportable gravity gradiometer, ''GGtop", constructed at the University of Birmingham. The device aims to simultaneously interrogate two physically separated, free-falling cold atom clouds using the technique of Raman interferometry to perform differential gravity measurements. Such a technique will suppress common-mode noise sources, such as vibrations, that otherwise limit classical gravimeters and cold atom interferometers based on single-cloud measurements. The technique is expected to improve speed and sensitivity for field measurements greatly. Using a combination of commercially available components and novel designs, intended to enhance portability and robustness, allowed for demonstration of atomic interference with the apparatus via Ramsey's method of separated oscillatory fields. The achieved fringe contrast of ~2%, defined as the difference in the number of atoms detected in IF = 2>, was limited by drifts stemming from some of the novel designs which prompted continued optimisation of the underpinning subsystems. To address performance issues parts of the experiment were redesigned with the goal of improving reliability at the expense of some portability. Using the retrofitted experiment, interference was once again achieved with fitted fringe spacing of 134.7±2.0 uS in good agreement with the 133.9 uS defined by the experimental control. A factor of 10 improvement in contrast was found with the central fringe demonstrating 18% of the atoms detected in the IF = 2> state when normalised to the total 3D MOT number. The 3.71 ± 0.01 kHz fitted linewidth of the central fringe gives a frequency uncertainty of 5.43 ± 0.01 x 10 - 7. This result leaves the experiment in a good position to begin making measurements of gravity