Digital Commons Network^™

Impact Of Software Changes On User Experience, Job Michael Champagne

LSU Doctoral Dissertations

Software changes are performed frequently to allow cutting edge features to be delivered to users in a timely manner and to assuage the ever increasing security vulnerabilities found in software. These changes, while necessary, can leave users dissatisfied with software that they use. Security patches can slow down computer performance, and extensive user interface changes can leave users dissatisfied. This research presents a methodology for identifying which software changes have high potential to cause user dissatisfaction. As a part of the methodology, we use natural language processing to analyze the software or system requirements business rule text to determine which …

Fatigue Damage Quantification And Life Estimation With Provision For Microstructure, Arash Pourbagheri Jirandehi

LSU Doctoral Dissertations

This dissertation provides methodologies for the quantification of different forms of fatigue damage by considering the role of microstructure. The laws of thermodynamics in conjunction with Finite Element Method (FEM) are utilized to devise thermodynamically-base frameworks for the estimation of cyclic damage in polycrystalline metals. Accordingly, a microstructure-sensitive platform for fatigue life estimation is introduced. The proposed framework is assessed for 3D printed metallic alloys at room and elevated temperatures. Further, it is used to analyze the fatigue performance difference between additively manufactured Inconel 718 in three print orientations. This research is of fundamental vital interest because it ensures that …

Assessing Mangrove Wetland Structure And Function Regulated By Environmental Gradients Under Climate Change And Increasing Human Impacts: A Modeling Approach, Xiaochen Zhao

LSU Doctoral Dissertations

Mangroves are blue-carbon-rich wetlands that can potentially contribute to climate change mitigation policies. However, mangroves are increasingly impacted by both natural and human disturbances worldwide that require restoration and rehabilitation programs to advance their conservation. Yet, there are major knowledge gaps in our understanding of how local resources (nutrients), regulators (e.g., salinity) and hydroperiod gradients interact in controlling mangrove role as carbon sink or source at different spatiotemporal scales under increasing disturbance frequency and climate change.

Here, I developed a mass-balance-based hydrology model to estimate soil porewater salinity (PWS) in riverine mangroves along the Shark River estuary (SRE), South Florida; …

Ontogeny And Resource Use Of Invasive Lionfish, Pterois Volitans, In Shallow Water Habitats Surrounding Summerland Key, Emily Shallow

LSU Master's Theses

The invasive red lionfish, Pterois volitans, has been shown to considerably reduce reef biomass via predation and competition in non-native ranges. Primary maintenance of lionfish is through human removal (e.g., culling), which does not sufficiently control the population due to deep-water spawning, recolonization of recently culled reefs, and ontogenetic migrations to mesophotic waters. Here, I investigated the diets and primary energy pathways during ontogeny in lionfish from the Florida Keys using stomach contents and stable isotope (δ¹³C and δ¹⁵N) analysis to better understand their role in the trophic food web. Additionally, isotopic overlap between lionfish …

Parent Play Correlates With Infants’ Object Construction Skill, Makayla Barber

Honors Capstones

No abstract provided.

Evaluating The Advantage Of Adaptive Strategies For Quantum Channel Distinguishability, Vishal Katariya, Mark M. Wilde

Faculty Publications

Recently, the resource theory of asymmetric distinguishability for quantum strategies was introduced by Wang et al. [Phys. Rev. Research 1, 033169 (2019)2643-156410.1103/PhysRevResearch.1.033169.]. The fundamental objects in the resource theory are pairs of quantum strategies, which are generalizations of quantum channels that provide a framework to describe an arbitrary quantum interaction. In the present paper we provide semidefinite program characterizations of the one-shot operational quantities in this resource theory. We then apply these semidefinite programs to study the advantage conferred by adaptive strategies in discrimination and distinguishability distillation of generalized amplitude damping channels. We find that there are significant gaps between …

Complex Attosecond Waveform Synthesis At Fel Fermi, Praveen Kumar Maroju, Cesare Grazioli, Michele Di Fraia, Matteo Moioli, Dominik Ertel, Hamed Ahmadi, Oksana Plekan, Paola Finetti, Enrico Allaria, Luca Giannessi, Giovanni De Ninno, Alberto A. Lutman, Richard J. Squibb, Raimund Feifel, Paolo Carpeggiani, Maurizio Reduzzi, Tommaso Mazza, Michael Meyer, Samuel Bengtsson, Neven Ibrakovic, Emma Rose Simpson, Johan Mauritsson, Tamás Csizmadia, Mathieu Dumergue, Sergei Kühn, Harshitha Nandiga Gopalakrishnan, Daehyun You, Kiyoshi Ueda, Marie Labeye, Jens Egebjerg Bækhøj, Kenneth J. Schafer, Elena V. Gryzlova, Alexei N. Grum-Grzhimailo

Faculty Publications

Free-electron lasers (FELs) can produce radiation in the short wavelength range extending from the extreme ultraviolet (XUV) to the X-rays with a few to a few tens of femtoseconds pulse duration. These facilities have enabled significant breakthroughs in the field of atomic, molecular, and optical physics, implementing different schemes based on two-color photoionization mechanisms. In this article, we present the generation of attosecond pulse trains (APTs) at the seeded FEL FERMI using the beating of multiple phase-locked harmonics. We demonstrate the complex attosecond waveform shaping of the generated APTs, exploiting the ability to manipulate independently the amplitudes and the phases …

Calet Observations During The First 5 Years On The Iss, P. S. Marrocchesi, O. Adriani, Y. Akaike, Y. Asaoka, E. Berti, G. Bigongiari, M. Bongi, P. Brogi, A. Bruno, N. Cannady, C. Checchia, M. L. Cherry, G. Collazuol, A. W. Ficklin, T. G. Guzik, M. Ichimura, M. H. Israel, K. Kasahara, Y. Kawakubo, J. F. Krizmanic, A. M. Messineo, J. W. Mitchell, S. Miyake, M. Mori, N. Mori, H. M. Motz, K. Munakata, L. Pacini, F. Palma, P. Papini, B. F. Rauch, S. B. Ricciarini, T. Sakamoto

Faculty Publications

The CALorimetric Electron Telescope CALET is collecting science data on the International Space Station since October 2015 with excellent and continuous performance. Energy is measured with a deep homogeneous calorimeter (1.2 nuclear interaction lengths, 27 radiation lengths) preceded by an imaging pre-shower (3 radiation lengths, 1mm granularity) providing tracking and 10-5 electron/proton discrimination. Two independent sub-systems identify the charge Z of the incident particle from proton to iron and above (Z<40). CALET measures the cosmic-ray electron + positron flux up to 20 TeV, gamma rays up to 10 TeV, and nuclei up to the PeV scale. In this paper, we report the on-orbit performance of the instrument and summarize the main results obtained during the first 5 years of operation, including the electron + positron energy spectrum and the individual spectra of protons, heavier nuclei and iron. Solar modulation and gamma-ray observations are also concisely reported, as well as transient phenomena and the search for gravitational wave counterparts.

Analysis Of The Photodegradation Of The Pro-Herbicide Benzobicyclon Hydrolysate Using A Seawater Gradient And Constituent Ions, Margaret A. Knight

Honors Capstones

No abstract provided.

Next-Generation Ensemble Projections Reveal Higher Climate Risks For Marine Ecosystems, Derek P. Tittensor, Camilla Novaglio, Cheryl S. Harrison, Ryan F. Heneghan, Nicolas Barrier, Daniele Bianchi, Laurent Bopp, Andrea Bryndum-Buchholz, Gregory L. Britten, Matthias Büchner, William W. L. Cheung, Villy Christensen, Marta Coll, John P. Dunne, Tyler D. Eddy, Jason D. Everett, Jose A. Fernandes-Salvador, Elizabeth A. Fulton, Eric D. Galbraith, Didier Gascuel, Jerome Guiet, Jasmin G. John, Jason S. Link, Heike K. Lotze, Olivier Maury, Kelly Ortega-Cisneros, Juliano Palacios-Abrantes, Colleen M. Petrik, Hubert Du Pontavice, Jonathan Rault, Anthony J. Richardson, Lynne Shannon, Yunne-Jai Shin

Faculty Publications

AbstractProjections of climate change impacts on marine ecosystems have revealed long-term declines in global marine animal biomass and unevenly distributed impacts on fisheries. Here we apply an enhanced suite of global marine ecosystem models from the Fisheries and Marine Ecosystem Model Intercomparison Project (Fish-MIP), forced by new-generation Earth system model outputs from Phase 6 of the Coupled Model Intercomparison Project (CMIP6), to provide insights into how projected climate change will affect future ocean ecosystems. Compared with the previous generation CMIP5-forced Fish-MIP ensemble, the new ensemble ecosystem simulations show a greater decline in mean global ocean animal biomass under both strong-mitigation …

Does The Loop Quantum Μo Scheme Permit Black Hole Formation?, Bao-Fei Li, Parampreet Singh

Faculty Publications

We explore the way different loop quantization prescriptions affect the formation of trapped surfaces in the gravitational collapse of a homogeneous dust cloud, with particular emphasis on the so-called mu o scheme in which loop quantum cosmology was initially formulated. Its undesirable features in cosmological models led to the so-called improved dynamics or the mu over bar scheme. While the jury is still out on the right scheme for black hole spacetimes, we show that as far as black hole formation is concerned, the mu o scheme has another, so far unknown, serious problem. We found that in the mu …

Search Full Text Options Here 1 Of 1 Constraints From Ligo O3 Data On Gravitational-Wave Emission Due To R-Modes In The Glitching Pulsar Psr J0537-6910, R. Abbott, T. D. Abbott

Faculty Publications

We present a search for continuous gravitational-wave emission due to r-modes in the pulsar PSR J0537-6910 using data from the LIGO-Virgo Collaboration observing run O3. PSR J0537-6910 is a young energetic X-ray pulsar and is the most frequent glitcher known. The inter-glitch braking index of the pulsar suggests that gravitational-wave emission due to r-mode oscillations may play an important role in the spin evolution of this pulsar. Theoretical models confirm this possibility and predict emission at a level that can be probed by ground-based detectors. In order to explore this scenario, we search for r-mode emission in the epochs between …

Development Of An Open Hardware 3-D Printed Conveyor Device For Continuous Cryopreservation Of Non-Batched Samples, Yue Liu, Melissa Eskridge, Amy Guitreau, Jacob Beckham, Megan Chesnut, Leticia Torres, Terrence R. Tiersch, William Todd Monroe

Faculty Publications

A great challenge among communities participating in germplasm repository development is to obtain suitable cryopreservation equipment and devices. Commercial programmable freezers are costly and thus unaffordable to many users. Self-made devices have substantial variability, resulting in few opportunities for standardization across communities. The development of open hardware with the increasing accessibility of three-dimensional (3-D) printing offers rapid prototyping and easy fabrication of devices by users around the world at low cost. The present study explored the feasibility of developing operational prototypes of 3-D printed motorized cryopreservation devices for continuous freezing of non-batched samples. A controlled cooling conveyor device (CCCD) was …

Association Between The Fto Rs9939609 Single Nucleotide Polymorphism And Dietary Adherence During A 2-Year Caloric Restriction Intervention: Exploratory Analyses From Calerie™ Phase 2, James L. Dorling, Daniel W. Belsky, Susan B. Racette, Sai Krupa Das, Eric Ravussin, Leanne M. Redman, Christoph Höchsmann, Kim M. Huffman, William E. Kraus, Michael S. Kobor, Julia L. Macisaac, David T.S. Lin, David L. Corcoran, Corby K. Martin

Clinical Research Faculty Publications

Caloric restriction (CR) improves markers of aging in humans; but it is not known if the fat mass and obesity-associated gene (FTO) rs9939609 single nucleotide polymorphism (SNP), which is associated with appetite and energy intake, influences adherence to prolonged CR. Utilizing data from the two-year Comprehensive Assessment of Long-term Effects of Reducing Intake of Energy (CALERIE™) phase 2 randomized controlled trial, we tested whether the FTO rs9939609 SNP was associated with adherence to CR in healthy adults without obesity. As secondary aims, we assessed whether the FTO rs9939609 SNP was associated with changes in body composition, biomarkers of aging, and …

Author Correction: Discovery And Confirmation Of The Shortest Gamma-Ray Burst From A Collapsar (Nature Astronomy, (2021), 5, 9, (917-927), 10.1038/S41550-021-01428-7), Tomás Ahumada, Leo P. Singer, Shreya Anand, Michael W. Coughlin, Mansi M. Kasliwal, Geoffrey Ryan, Igor Andreoni, S. Bradley Cenko, Christoffer Fremling, Harsh Kumar, Peter T.H. Pang, Eric Burns, Virginia Cunningham, Simone Dichiara, Tim Dietrich, Dmitry S. Svinkin, Mouza Almualla, Alberto J. Castro-Tirado, Kishalay De, Rachel Dunwoody, Pradip Gatkine, Erica Hammerstein, Shabnam Iyyani, Joseph Mangan, Dan Perley, Sonalika Purkayastha, Eric Bellm, Varun Bhalerao, Bryce Bolin, Mattia Bulla, Christopher Cannella, Poonam Chandra, Dmitry A. Duev

Faculty Publications

In the version of this Letter initially published, the Acknowledgements section omitted to include the following: “Based on observations obtained at the international Gemini Observatory, a program of NSF’s NOIRLab, which is managed by the Association of Universities for Research in Astronomy (AURA) under a cooperative agreement with the National Science Foundation on behalf of the Gemini Observatory partnership: the National Science Foundation (United States), National Research Council (Canada), Agencia Nacional de Investigación y Desarrollo (Chile), Ministerio de Ciencia, Tecnología e Innovación (Argentina), Ministério da Ciência, Tecnologia, Inovações e Comunicações (Brazil), and Korea Astronomy and Space Science Institute (Republic of …

On The Topological Complexity Of Manifolds With Abelian Fundamental Group, Daniel C. Cohen, Lucile Vandembroucq

Faculty Publications

We find conditions which ensure that the topological complexity of a closed manifold M with abelian fundamental group is nonmaximal, and see through examples that our conditions are sharp. This generalizes results of Costa and Farber on the topological complexity of spaces with small fundamental group. Relaxing the commutativity condition on the fundamental group, we also generalize results of Dranishnikov on the Lusternik-Schnirelmann category of the cofibre of the diagonal map Δ:M→M×M{\Delta:M\to M\times M} for nonorientable surfaces by establishing the nonmaximality of this invariant for a large class of manifolds.

Event-Triggered Control Using A Positive Systems Approach, Frédéric Mazenc, Michael Malisoff, Corina Barbalata, Zhong Ping Jiang

Faculty Publications

We provide a new event-triggered control strategy that relies on the notion of positive systems. Our results cover output feedback, and robustness with respect to uncertain dynamics. Our proofs are based on interval observers. Our examples show potential advantages of our approach over earlier event-triggered methods.

Floodplain Forests Vegetation Dynamics Driven By Water Deficits Across Scales, Nga Thanh Nguyen

LSU Doctoral Dissertations

Restoration of floodplain ecosystems relies on identifying the most crucial hydrologic process which has been altered by human and climate. Flooding is a well-known dominant hydrologic process for floodplain ecosystems, but surprisingly little is known about drought's role in structuring ecosystems. In addition, several issues remained uncertain, such as the nature of drought within floodplains and the sensitivity of floodplain species-specific growth to climate. These gaps of understanding have in common in missing observations of mechanistic pathways of vegetation response to water deficits at multiple scales in time and space.Generally, this research contributed to floodplain management by expanding our understanding …

Colloidal Nanomaterial Surface Chemistry And Characterization Studied By Linear And Nonlinear Spectroscopy, Asela Sampath Dikkumbura

LSU Doctoral Dissertations

Recent studies have demonstrated the use of nanomaterials such as metallic nanoparticles, liposomes, and polymer microparticles for biomedical applications, encompassing the field of nanomedicine. For developing novel core-shell metallic nanoparticles with controlled surface morphology, the in situ growth dynamics of colloidal silver-gold core-shell (Ag@Au CS) nanoparticles (NPs) in water are monitored in a stepwise synthesis approach using time-dependent second harmonic generation (SHG) and extinction spectroscopy. Transmission electron microscopy images show that the CS NP surface morphology becomes more smooth and uniform as the reaction proceeds, corresponding to lower, stable SHG signals and narrower plasmonic spectra that are compared to finite-difference …

Ross Sea Dissolved Organic Matter Optical Properties During An Austral Summer: Biophysical Influences, Eurico J. D'Sa, Hyun-Cheol Kim, Sun-Yong Ha, Ishan Joshi

Faculty Publications

The Ross Sea, one of the most productive regions in the Southern Ocean, plays a significant role in deep water formation and carbon cycling. Dissolved organic carbon (DOC) concentrations and chromophoric dissolved organic matter (CDOM) absorption and fluorescence (FDOM) properties were studied in conjunction with biophysical properties during austral summer. Elevated values of both DOC (mean 47.82 ± 5.70 μM) and CDOM (absorption coefficient at 325 nm, acdom325: mean 0.31 ± 0.18 m–1) observed in the upper shelf waters in the southwest (SW), north of the Ross Ice Shelf (RIS), the northwest and along a transect inward of the shelf …

Shape-Based Classification Of Partially Observed Curves, With Applications To Anthropology, Gregory J. Matthews, Karthik Bharath, Sebastian Kurtek, Juliet K. Brophy, George K. Thiruvathukal, Ofer Harel

Faculty Publications

We consider the problem of classifying curves when they are observed only partially on their parameter domains. We propose computational methods for (i) completion of partially observed curves; (ii) assessment of completion variability through a nonparametric multiple imputation procedure; (iii) development of nearest neighbor classifiers compatible with the completion techniques. Our contributions are founded on exploiting the geometric notion of shape of a curve, defined as those aspects of a curve that remain unchanged under translations, rotations and reparameterizations. Explicit incorporation of shape information into the computational methods plays the dual role of limiting the set of all possible completions …

A Clark-Ocone Type Formula Via Itô Calculus And Its Application To Finance, Takuji Arai, Ryoichi Suzuki

Journal of Stochastic Analysis

No abstract provided.

Classifying Soft X-Ray Objects In The Galactic Bulge, Joshua D. Wetuski

LSU Doctoral Dissertations

The Galactic Bulge Survey (GBS) is a broad and shallow X-ray survey designed to detect quiescent X-ray binary systems in the direction of the Milky Way bulge, which include objects such as low-mass X-ray binaries, cataclysmic variables, and symbiotic binaries. LMXBs can provide constraints to the neutron star equation of state and symbiotic systems and are likely progenitors of double white dwarf systems which are themselves candidate progenitors to type Ia supernova. We seek to improve identification and classification of optical counterparts to GBS in several ways. By improving upon the original GBS, an updated catalog was created to help …

The Young Black Girl: A Narration Of Stem Identity Through Science Origin In Elementary School, Heather F. Lavender

LSU Doctoral Dissertations

An ethnographic qualitative case study was conducted by examining the perceptions of two 5^th grade Black girls at an independent school about their involvement with school science, the impact of race and gender towards their perception, and the influence of teachers, peers, and family on their science identity. Black girls are often relegated to outsider status within the classroom, lacking power and authority, which results in Black girls being denied a rightful presence in their learning community (Dumas & Ross, 2016). Additionally, their presence in STEM careers does not reflect their presence nationwide (Graves et al., 2014). The proposed …

Calculating Infinitesimal Generators, Majnu John, Yihren Wu

Journal of Stochastic Analysis

No abstract provided.

Novel Optimal Multisensor Placement For Indoor Rectilinear Line-Of-Sight Coverage, Prasanga Neupane, Guannan Liu, Hsiao Chun Wu, Shih Yu Chang, Jinwei Ye

Faculty Publications

Optimal multisensor placement/deployment for an arbitrary indoor geometry still remains very challenging nowadays. It is preferable to minimize the number of sensors which can still cover the entire indoor space with a balanced load. However, this multi-objective problem is quite complex in practice. In this work, we will study this critical multisensor placement problem mathematically and algorithmically and propose a systematic approach to tackle this problem. In this paper, we focus on the line-of-sight (LoS) coverage within a rectilinear indoor environment and the sensors' locations are restricted on the perimeter. Our proposed new approach consists of two stages. First, a …

Recursive And Viterbi Estimation For Semi-Markov Chains, Robert J. Elliott, W. P. Malcolm

Journal of Stochastic Analysis

No abstract provided.

Diffusional Fractionation Of Helium Isotopes In Silicate Melts, Haiyang Luo, Bijaya Karki, Dipta B. Ghosh, Huiming Bao

Faculty Publications

Estimating Helium (He) concentration and isotope composition of the mantle requires quantifying He loss during magma degassing. The knowledge of diffusional He isotope fractionation in silicate melts may be essential to constrain the He loss. Isotopic mass dependence of He diffusion can be empirically expressed as D3He/D4He = (4/3)^β, where D is the diffusivity of a He isotope. However, no studies have reported any β values for He in silicate melts due to technical challenges in both experiments and computations. Here, molecular dynamics simulations based on deep neural network potentials trained by ab initio data …

The N-Dimensional Quadratic Heisenberg Algebra As A “Non–Commutative” Sl(2,C), Luigi Accardi, Andreas Boukas, Yun-Gang Lu

Journal of Stochastic Analysis

No abstract provided.

Enviromic Assembly Increases Accuracy And Reduces Costs Of The Genomic Prediction For Yield Plasticity In Maize, Germano Costa-Neto, Jose Crossa, Roberto Fritsche-Neto

Faculty Publications

Quantitative genetics states that phenotypic variation is a consequence of the interaction between genetic and environmental factors. Predictive breeding is based on this statement, and because of this, ways of modeling genetic effects are still evolving. At the same time, the same refinement must be used for processing environmental information. Here, we present an “enviromic assembly approach,” which includes using ecophysiology knowledge in shaping environmental relatedness into whole-genome predictions (GP) for plant breeding (referred to as enviromic-aided genomic prediction, E-GP). We propose that the quality of an environment is defined by the core of environmental typologies and their frequencies, which …