Physical Sciences and Mathematics Commons^™

Quid Pro Quo: An Exploration Of Reciprocity In Code Review, Carlos Gavidia-Calderon, Donggyun Han, Amel Bennaceur

Research Collection School Of Computing and Information Systems

We explore the role of reciprocity in code review processes. Reciprocity manifests itself in two ways: 1) reviewing code for others translates to accepted code contributions, and 2) having contributions accepted increases the reviews made for others. We use vector autoregressive (VAR) models to explore the causal relation between reviews performed and accepted contributions. After fitting VAR models for 24 active open-source developers, we found evidence of reciprocity in 6 of them. These results suggest reciprocity does play a role in code review, that can potentially be exploited to increase reviewer participation.

Cost-Effective And Collaborative Methods To Author Video's Scene Description For Blind People, Rosiana Natalie

Research Collection School Of Computing and Information Systems

The majority of online video content remains inaccessible for blind people due to the lack of audio descriptions. Content creators have traditionally relied on professionals to author audio descriptions, but their service is costly and not readily available. In this research, I introduce four threads of research that I will conduct for my Ph.D. dissertation, aimed to create methods and tools that are both time- and cost-effective in providing good quality audio descriptions. They are: (i) The development and evaluation of mixed-ability collaboration authoring tool, (ii) The formative study to uncover the feedback pattern from the reviewer, (iii) the evaluation …

Software Engineering User Study Recruitment On Prolific: An Experience Report, Brittany Reid, Markus Wagner, Marcelo D’Amorim, Christoph Treude

Research Collection School Of Computing and Information Systems

Online participant recruitment platforms such as Prolific have been gaining popularity in research, as they enable researchers to easily access large pools of participants. However, participant quality can be an issue; participants may give incorrect information to gain access to more studies, adding unwanted noise to results. This paper details our experience recruiting participants from Prolific for a user study requiring programming skills in Node.js, with the aim of helping other researchers conduct similar studies. We explore a method of recruiting programmer participants using prescreening validation, attention checks and a series of programming knowledge questions. We received 680 responses, and …

On Recruiting Experienced Github Contributors For Interviews And Surveys On Prolific, Felipe Ebert, Alexander Serebrenik, Christoph Treude, Nicole Novielli, Fernando Castor

Research Collection School Of Computing and Information Systems

Software engineering researchers have been using general purpose online tools for crowd-sourcing for quite some time. Those tools can be useful to recruit participants for research studies as they are paid for their time. However, those tools should be used carefully. In this paper, we have described the issues we faced when recruiting participants on Prolific. We used Prolific to recruit open-source developers with experience in submitting and reviewing pull requests (PRs). However, we did not succeed in obtaining valid participants for either the interview or the survey, which led us to change the approach of our study and not …

Hci Education And Ux Practice: Highlights From Singapore, Tamas Makany, Dharani Perera-Schulz

Research Collection Lee Kong Chian School Of Business

This position paper highlights trends in education, practice, and support of HCI/UX in Singapore, a small city-state island in Southeast Asia. The paper was prepared for the 2022 Southeast Asia Computer-Human Interaction (SEACHI'22) virtual workshop on Apr 14, 2022, as part of the ACM CHI Conference on Human Factors in Computing Systems (CHI'22) international conference.

Machine Learning Classification Of Digitally Modulated Signals, James A. Latshaw

Electrical & Computer Engineering Theses & Dissertations

Automatic classification of digitally modulated signals is a challenging problem that has traditionally been approached using signal processing tools such as log-likelihood algorithms for signal classification or cyclostationary signal analysis. These approaches are computationally intensive and cumbersome in general, and in recent years alternative approaches that use machine learning have been presented in the literature for automatic classification of digitally modulated signals. This thesis studies deep learning approaches for classifying digitally modulated signals that use deep artificial neural networks in conjunction with the canonical representation of digitally modulated signals in terms of in-phase and quadrature components. Specifically, capsule networks are …

Chen-Fliess Series For Linear Distributed Systems, Natalie T. Pham

Electrical & Computer Engineering Theses & Dissertations

Distributed systems like fluid flow and heat transfer are modeled by partial differential equations (PDEs). In control theory, distributed systems are generally reformulated in terms of a linear state space realization, where the state space is an infinite dimensional Banach space or Hilbert space. In the finite dimension case, the input-output map can always be written in terms of a Chen-Fliess functional series, that is, a weighted sum of iterated integrals of the components of the input function. The Chen-Fliess functional series has been used to describe interconnected nonlinear systems, to solve system inversion and tracking problems, and to design …

A Direct Method For Modeling And Simulations Of Elliptic And Parabolic Interface Problems, Kumudu Janani Gamage

Mathematics & Statistics Theses & Dissertations

Interface problems have many applications in physics. In this dissertation, we develop a direct method for solving three-dimensional elliptic interface problems and study their application in solving parabolic interface problems. As many of the physical applications of interface problems can be approximated with partial differential equations (PDE) with piecewise constant coefficients, our derivation of the model is focused on interface problems with piecewise constant coefficients but have a finite jump across the interface. The critical characteristic of the method is that our computational framework is based on a finite difference scheme on a uniform Cartesian grid system and does not …

Investigating Gluonic Operators In Coordinate Space, Wayne Henry Morris Iii

Physics Theses & Dissertations

In this dissertation, a method of extracting gluon momentum distributions inside hadrons, and particularly nucleons, is developed. In general, the utility and application of performing calculations in coordinate space at the operator level is discussed, and its application to the method of pseudodistributions in the lattice extraction of parton distributions. An introduction to the background field method and other techniques used in the calculation of corrections to gluon operators are provided. Then, an outline of the calculation of the uncontracted gluon bilocal operator at one-loop is given, and the result thereof. Using the result for the gluon bilocal operator restricted …

Studies Of Bonus12 Radial Gem Detector And Tcs Beam Spin Asymmetry In Clas12, Jiwan Poudel

Physics Theses & Dissertations

The Barely Offshell Nucleon Structure (BONuS12) experiment adopted the concept of spectator tagging technique to study the nearly-free neutron structure function F2n in the CLAS12 of Jefferson Lab. A novel Radial Time Projection Chamber (RTPC) detector was built, tested and integrated into the CLAS12 system to detect a back-moving low momentum tagged proton in d(e, ep)X deep-inelastic scattering. It was a 40 cm long gaseous detector consisting of 3 layers of cylindrical GEM foils for the charge amplification, with the data readout directly from the surrounding padboard. The RTPC detected the recoiling spectator proton, in coincidence with …

Experimental Investigation Of All-Optical Production Of Metastable Krypton, Joshua Carl Frechem

Physics Theses & Dissertations

Metastable production of noble gases requires significant energy due to their filled valence shells. These transitions from the ground state are in the vacuum ultraviolet and extreme ultraviolet, which are relatively inaccessible to lasers. This necessitates the use of either electron/ion bombardment via inefficient glow discharges or the use of high-power lasers and nonlinear processes. The all-optical production efficiency using these high-power lasers promises to be orders of magnitude higher than glow discharges, but far more costly. This work looks to improve all-optical production of metastable krypton (Kr*) through the use of a commercially available vacuum ultraviolet lamp with a …

Ion Production And Mitigation In Dc High-Voltage Photo-Guns, Joshua T. Yoskowitz

Physics Theses & Dissertations

One of the biggest obstacles to operating a GaAs polarized electron source with a long charge lifetime is the mitigation of ion back-bombardment. Several techniques exist to either clear ions from the accelerator or to mitigate ion damage of the photocathode. Predicting the effectiveness of these techniques requires sophisticated simulation models of electron impact ionization within the photo-gun. In this work, the effectiveness of applying a positive anode bias voltage to mitigate ion damage and increase the charge lifetime of the GaAs photocathode was studied over three run periods at the Continuous Electron Beam Accelerator Facility (CEBAF) at Jefferson Lab …

Electromagnetic Modeling Of A Wind Tunnel Magnetic Suspension And Balance System, Desiree Driver

Mechanical & Aerospace Engineering Theses & Dissertations

Wind tunnels are used to study forces and moments acting on an aerodynamic body. While most results involve some interference from the mechanical supports used to hold the model, a Magnetic Suspension and Balance System (MSBS) is void of these interferences and presents an ideal test scenario. To further investigate the feasibility of dynamic stability testing at supersonic speeds using a MSBS, a preliminary design idea is currently being developed using an existing MSBS in a subsonic wind tunnel. This review focuses on the development of a mathematical model to more accurately portray the capabilities of the 6 inch Massachusetts …

Development Of Modeling And Simulation Platform For Path-Planning And Control Of Autonomous Underwater Vehicles In Three-Dimensional Spaces, Sai Krishna Abhiram Kondapalli

Mechanical & Aerospace Engineering Theses & Dissertations

Autonomous underwater vehicles (AUVs) operating in deep sea and littoral environments have diverse applications including marine biology exploration, ocean environment monitoring, search for plane crash sites, inspection of ship-hulls and pipelines, underwater oil rig maintenance, border patrol, etc. Achieving autonomy in underwater vehicles relies on a tight integration between modules of sensing, navigation, decision-making, path-planning, trajectory tracking, and low-level control. This system integration task benefits from testing the related algorithms and techniques in a simulated environment before implementation in a physical test bed. This thesis reports on the development of a modeling and simulation platform that supports the design and …

Deep Learning Object-Based Detection Of Manufacturing Defects In X-Ray Inspection Imaging, Juan C. Parducci

Mechanical & Aerospace Engineering Theses & Dissertations

Current analysis of manufacturing defects in the production of rims and tires via x-ray inspection at an industry partner’s manufacturing plant requires that a quality control specialist visually inspect radiographic images for defects of varying sizes. For each sample, twelve radiographs are taken within 35 seconds. Some defects are very small in size and difficult to see (e.g., pinholes) whereas others are large and easily identifiable. Implementing this quality control practice across all products in its human-effort driven state is not feasible given the time constraint present for analysis.

This study aims to identify and develop an object detector capable …

The Impact Of Shoreline Stabilization On Sediment Supply And Ecogeomorphology: Assessing Marsh Response To Altered Wave Energies, Lake Borgne, Louisiana, Jessica J. Villers

LSU New Orleans Theses and Dissertations

Shoreline protection structures are a common response to lateral erosion in marshes, but limited studies exist on how they influence sediment supply and the resulting ecogeomorphology. This study investigates the impacts of marine mattresses, geotextile cages filled with riprap, in Lake Borgne, LA. A field study was conducted during cold front passages at a site with marine mattresses and a proximal control site without, collecting measurements of water depth, wave energy, lateral erosion, sediment accumulation, vegetation, and sediment characteristics. Wetlands with marine mattresses attenuated waves more than their natural marsh edge counterparts, which have limited conditions favorable for sedimentation. However, …

Video Games, Grief, And The Character Link System, Nam Nguyen

LSU New Orleans Theses and Dissertations

Grief can encompass more than just the loss of real-life people. It can be felt with the loss of a pet, changes in daily structure, and even the loss of video game characters. The topic of grief related to video games and video game characters comes at a time when games as a service (GaaS) continue to increase in popularity and the phenomenon where these games also inevitably terminate service. To combat this unique form of grief, the Character LINK System was created as a tool that uses simple natural language processing (NLP) techniques to offer support to the bereaved …

Design And Synthesis Of Novel Synthetic Cannabinoid 5-Hydroxy-1h-Indazole-3-Carboxamide Metabolites, Nichole Ann Pianovich

LSU New Orleans Theses and Dissertations

Since the discovery of Δ⁹-THC, the pharmaceutical industry has continuously developed synthetic analogs intending to develop compounds that exhibit the bioactivity of natural cannabinoids but are devoid of its psychoactivity. Synthetic cannabinoids often exhibit potencies significantly greater than Δ⁹-THC, as do their metabolites. Phase I metabolism of synthetic cannabinoids bearing an indazole core predominantly proceeds through oxidative transformations to produce mono-hydroxylated variants of the parent compound. Recent studies have primarily focused on N-1/C-3 hydroxylated pentyl side chains and carboxamide linked groups. These compounds often retain affinity and potency for the CB₁ receptor …

Synthesis Of Inorganic-Organic Perovskite Hybrid Materials Via A Microwave Assisted Method, Anamika Poduval

LSU New Orleans Theses and Dissertations

The research presented here focusses on fabrication of organic modified inorganic two-dimensional and three-dimensional materials via microwave assisted methods. These hybrid materials are of importance due to their capacity to incorporate the characteristics of both organic and inorganic components. Microwave methods have been utilized to expedite the topochemical modification of layered perovskites. In one set of studies, microwave assisted grafting reactions were performed on layered perovskite (HLaNb₂O₇) materials with a series of hydroxy carboxylic acids. The reactivities of these organic compounds with the layered perovskites and the influence of precursor, temperature and time are demonstrated. The …

Levee Seepage Identification From Aerial Images Using Machine Learning, Sofiane Benkara

LSU New Orleans Theses and Dissertations

Levees protect from natural disasters that can threaten human health, infrastructure, and biological systems by protecting low-lying lands near or below sea level from flooding. However, seepage in those levees undermines their structural integrity, leading to failures. Today the United States has approximately over a hundred thousand miles of levee, many of which are reaching or have surpassed their initial design life. Given the concern, there is a need to develop reliable, rapid, and non-intrusive levee monitoring systems to detect the presence of seepage. This study explores the use of Deep Convolutional Neural Network (DCNN) integrated with Discrete Cosine Transform …

Into The Depths: Climate Change Part 3, Felicia Bedford

D.U.Quark

No abstract provided.

Outdoor Play In Preschool Children: Parent Attitudes And Loose Part Play In Urban Settings, Ann Spilker

School of Natural Resources: Dissertations, Theses, and Student Research

Outdoor play is an important aspect of young children’s health social-cognitive development. However, play in natural environments is declining due to urbanization and various safety concerns. Many urban preschools have outdoor play spaces that lack natural elements that stimulate children’s autonomy, creativity, and imaginative play. Furthermore, parents who find outdoor environments intimidating and fraught with danger limit young children’s outdoor experiences that inhibit their motor fitness, socialization with peers, and ecological awareness. Two qualitative case studies examined preschool children’s outdoor play. Study one focused on preschool children’s loose parts play in urban settings while study two examined parent’s attitudes towards …

Estimating The Analytical Performance Of Raman Spectroscopy For Quantification Of Active Ingredients In Human Stratum Corneum, Hichem Kichou, Emilie Munnier, Yuri Dancik, Kamilia Kemel, Hugh Byrne, Ali Tfayli, Dominique Bertrand, Martin Soucé, Igor Chourpa, Franck Bonnier

Articles

Confocal Raman microscopy (CRM) has become a versatile technique that can be applied routinely to monitor skin penetration of active molecules. In the present study, CRM coupled to multivariate analysis (namely PLSR—partial least squares regression) is used for the quantitative measurement of an active ingredient (AI) applied to isolated (ex vivo) human stratum corneum (SC), using systematically varied doses of resorcinol, as model compound, and the performance is quantified according to key figures of merit defined by regulatory bodies (ICH, FDA, and EMA). A methodology is thus demonstrated to establish the limit of detection (LOD), precision, accuracy, sensitivity (SEN), and …

Red Harvester Ant (Pogonomyrmex Barbatus F. Smith; Hymenoptera: Formicidae) Preference For Cover Crop Seeds In South Texas, Lilly Victoria Elliott-Vidaurri, Daniella Rivera, Adrian Noval, Robin A. Choudhury, Hannah J. Penn

School of Earth, Environmental, & Marine Sciences Faculty Publications

Harvester ants often selectively forage seeds, causing these ants to be viewed as pests in agricultural areas where they may forage on crop seeds. While little research has been done on harvester ant preferences for cover crop seeds, grower observations in the Lower Rio Grande Valley (LRGV) suggest that ants may remove these seeds before germination. We examined red harvester ant (Pogonomyrmex barbatus F. Smith) preferences for cover crop seeds (fescue, oat, sunn hemp, radish, vetch, and wheatgrass) and the effects of a commonly used bacterial seed inoculant. We evaluated relative preferences using seed depots presented to colonies with no …

Air, Land, And Water Variables Associated With The First Appearance And Current Spatial Distribution Of Toxic Prymnesium Parvum Blooms In Reservoirs Of The Southern Great Plains, Usa, Shisbeth Tábora-Sarmiento, Reynaldo Patiño, Carlos Portillo-Quintero, Cade Coldren

United States Geological Survey: Staff Publications

This study examined the association of air, land, and water variables with the first historical occurrence and current distribution of toxic Prymnesium parvum blooms in reservoirs of the Brazos River and Colorado River, Texas (USA). One impacted and one reference reservoir were selected per basin. Land cover and use variables were estimated for the whole watershed (WW) and a 0.5-km zone on either side of streams (near field, NF). Variables were expressed in annual values. Principal component and trend analyses were used to determine (1) differences in environmental conditions before and after the 2001 onset of toxic blooms in impacted …

Systems-Based Approach For Optimization Of Assembly-Free Bacterial Mlst Mapping, Natasha Pavlovikj, Joao Carlos Gomes-Neto, Jitender Deogun, Andrew Benson

School of Computing: Faculty Publications

Epidemiological surveillance of bacterial pathogens requires real-time data analysis with a fast turnaround, while aiming at generating two main outcomes: (1) species-level identification and (2) variant mapping at different levels of genotypic resolution for population-based tracking and surveillance, in addition to predicting traits such as antimicrobial resistance (AMR). Multilocus sequence typing (MLST) aids this process by identifying sequence types (ST) based on seven ubiquitous genome-scattered loci. In this paper, we selected one assembly-dependent and one assembly-free method for ST mapping and applied them with the default settings and ST schemes they are distributed with, and systematically assessed their accuracy and …

Dissociative Excitation, Ionization, And Fragmentation Processes For Nitrogen, Oxygen, Methane, And Water Molecules By Electron Bombardment, M. Gochitashvili, R. Lomsazde, D. Kuparashvili, O. Taboridze, Roman Ya. Kezerashvili

Publications and Research

Electron–impact ionization and fragmentation of molecules are investigated by the chromatography mass-spectrometry device. While the excitation processes are investigated by an optical spectroscopy method. The spectral analysis is performed in the vacuum ultraviolet 50-130 nm spectral regions. The absolute value of the fragmentation cross-section in the dissociative ionization and excitation processes is determined. Measurements are performed in the electron energy range 25-120eV for ionization and 200-500eV for excitation processes respectively.

Synthesis And Characterization Of Silver Thione Complexes, Audrey V. Lawrence

Honors Theses

Coordination polymers are repeating units of a coordination complex that have applications as catalysts, conductors, and magnets. In this work, silver (I) was the metal of choice because it behaves similarly to copper (I), which has been studied much more extensively and thione ligands were chosen due to their potential for forming coordination polymers. These coordination complexes with silver were synthesized by combining silver nitrate with thioacetamide, N,N'-diphenylthiourea, and 2-mercapto-1-methylimidazole. These complexes were characterized via IR spectroscopy, elemental analysis, and X-ray crystallography. Silver thioacetamide was determined to form a coordination complex through the sulfur to form a trigonal crystal lattice …

Target Of Glut4 Regulating Protein Tug-Ubl1 To Treat Insulin Resistant Type Two Diabetes, Megan Kohout

Chemistry Student Work

Type two diabetes mellitus is a highly prevalent disease for which the mechanism of insulin signaling to initiate glucose uptake in cleaving TUG-UBL1 by the protease Usp25m is currently not well understood. As increased insulin resistance can lead to the development of type one insulin deficient diabetes, the knowledge of this pathway may uncover underlying causes of insulin resistance. This research aims to understand the effect and stoichiometry of Usp25m binding to TUG-UBL1 in relationship to the cleavage of TUG-UBL1 initiating translocation of GLUT4 glucose transporter. The action of protease effector PIST will be investigated to understand the importance of …

Bis(Tryptophan) Amphiphiles: Design, Synthesis And Efficacy As Antimicrobial Agents, Michael Mckeever

Dissertations

Amphiphiles play important roles in nature. These molecules contain both hydrophilic and hydrophobic regions, leading to some astonishing properties. The lipid bilayer of the cell membrane is a fascinating organization of amphiphilic phospholipids. Natural and synthetic amphiphiles, such as antimicrobial peptides, interact with the cell membrane. Such interactions can impact transport of molecules across the cell membrane, disrupting cell functions. In this work, a library of tryptophan-containing amphiphiles was synthesized and their antimicrobial properties were explored.

First, a library of bis(tryptophan) amphiphiles was synthesized. Preparation included a coupling reaction of a diamine with tryptophan residues, via their carboxy-termini, at …