Digital Commons Network^™

"The Law Doesn't Work Like A Computer": Exploring Software Licensing Issues Faced By Legal Practitioners, Nathan Wintersgill, Trevor Stalnaker, Laura A. Heymann, Oscar Chaparro, Denys Poshyvanyk

Faculty Publications

Most modern software products incorporate open source components, which requires compliance with each component’s licenses. As noncompliance can lead to significant repercussions, organizations often seek advice from legal practitioners to maintain license compliance, address licensing issues, and manage the risks of noncompliance. While legal practitioners play a critical role in the process, little is known in the software engineering community about their experiences within the open source license compliance ecosystem. To fill this knowledge gap, a joint team of software engineering and legal researchers designed and conducted a survey with 30 legal practitioners and related occupations and then held 16 …

Characteristics Of Pyrolysis Products Of California Chaparral And Their Potential Effect On Wildland Fires, Mahsa Alizadeh, David R. Weise, Thomas H. Fletcher

Faculty Publications

The aim of this study was to investigate the pyrolysis of selected California foliage and estimate the energy content of the released volatiles to show the significance of the pyrolysis of foliage and its role during wildland fires. While the majority of the volatiles released during the pyrolysis of foliage later combust and promote fire propagation, studies on the energy released from combustion of these compounds are scarce. Samples of chamise (Adenostoma fasciculatum), Eastwood’s manzanita (Arctostaphylos glandulosa), scrub oak (Quercus berberidifolia), hoaryleaf ceanothus (Ceanothus crassifolius), all native to southern California, and sparkleberry …

Derivative Propagation Through Vortex Particle Method Simulation, Eric Green, Andrew Ning

Faculty Publications

Automatic differentiation (AD) is a powerful tool for evaluating numerical derivatives. In particular, reverse-mode AD provides numerical gradients in a way that is insensitive to the number of input variables. This makes reverse-mode AD well-suited for solving large optimization problems. However, reverse-mode AD has a particularly large associated memory cost because most intermediate values in operations need to be cached. This is problematic for large problems such as aerodynamics simulations, though, since the memory requirements can quickly become impractical. The solution implemented in this work is to provide analytic pullback expressions for functions for which many of the intermediate values …

Geometrically Exact Beam Theory For Gradient-Based Optimization, Taylor Mcdonnell, Andrew Ning

Faculty Publications

Decades of research have progressed geometrically exact beam theory to the point where it is now an invaluable resource for analyzing and modeling highly flexible slender structures. Large-scale optimization using geometrically exact beam theory remains nontrivial, however, due to the inability of gradient-free optimizers to handle large numbers of design variables in a computationally efficient manner and the difficulties associated with obtaining smooth, accurate, and efficiently calculated design sensitivities for gradient-based optimization. To overcome these challenges, this paper presents a finite-element implementation of geometrically exact beam theory which has been developed specifically for gradient-based optimization. A key feature of this …

Trajectory Optimization Of Evtol And Conventional Aircraft: A Comparative Analysis Of Vortex Particle Method And Vortex Lattice + Blade Element Momentum Theory, Andrew Tagg, Ryan Anderson, Cibin Joseph, Andrew Ning

Faculty Publications

Trajectory optimization of aircraft transition maneuvers can significantly influence the design of these systems, particularly when making decisions about aircraft geometry, propulsion sizing, and control system design. This paper presents the trajectory optimization of air vehicles including electric vertical takeoff and landing (eVTOL) as well as conventional aircraft. The study evaluates the influence of fidelity in trajectory design by comparing the use of two aerodynamic methods in the context of trajectory optimization. The mid-fidelity method utilizes a vortex lattice method (VLM) to model lifting surfaces while employing blade element momentum theory (BEMT) to model rudimentary rotor-wing interactions. The high-fidelity approach …

Solving Unsteady Potential Flow Problems In O(N) Time, Ryan Anderson, Andrew Ning

Faculty Publications

Design of vertical takeoff and landing aircraft is challenging in part due to significant aerodynamic interactions between rotors and wings. Computational models can aid in their design, but are computationally expensive. 3-D panel methods coupled with vortex particle wakes offer an attractive solution, but solving for the panel strengths scales poorly for large problems. Multigrid methods, such as Krylov subspace methods in conjunction with the fast multipole method (FMM), have been demonstrated to reduce the scaling to O(𝑁). We explore the performance and limitations of the Krylov-FMM method, traditional matrix-powered GMRES, LU decomposition, and a novel O(𝑁) multigrid approach to …

Persevering Through Communication Challenges: A Qualitative Descriptive Exploration Of Communication Experiences In Aphasia, Tyson G. Harmon, Camille Williams, Garrett Cardon, William S. Evans

Faculty Publications

Background

People with aphasia often experience activity limitations and participation restrictions despite wanting to engage in communication activities that are satisfying and meaningful. Communication partner support, the complexity of the communication environment, and the thoughts and feelings of people with aphasia have important implications for both language processing and communicative participation. The perspectives of PWA about the role that environmental and personal factors (e.g. thoughts and feelings) play in their communication experiences could inform clinical practice.

Aims

To qualitatively explore the communication experiences of people with aphasia and how environmental demands and personal factors (especially emotional responses) affect these experiences. …

An Integrated Space Test Lexicon: A Taxonomy For The Integrated Test And Evaluation Of Space Systems, Stephen K. Tullino, Andrew S. Keys, Robert A. Bettinger, Amy M. Cox, David R. Jacques

Faculty Publications

The proposed Integrated Space Test Lexicon is intended to amalgamate the numerous definitions of integrated (IT or IT&E), development test (DT or DT&E), and operational test (OT or OT&E) into unified, service-wide definitions, aligned with the Space Test Enterprise Vision. Refining such definitions will help distill the core characteristics of these fundamental test types to first identify space system activities composing what is traditionally known as DT and OT, then to provide a means of how these activities fit into the IT paradigm and support space system development. In forging a common understanding of how DT and OT support space …

Persistent Behavior In Solar Energetic Particle Time Series, N V. Sarlis, G Livadiotis, D J. Mccomas, M E. Cuesta, L Y. Khoo, C M S Cohen, D G. Mitchell, Nathan A. Schwadron

Faculty Publications

We investigate the long-term persistence of solar energetic particle (SEP) time series by means of four different methods: Hurst rescaled range R/S analysis, detrended fluctuation analysis, centered moving average analysis, and the fluctuation of natural time under the time reversal method. For these analyses, we use data sets from the Integrated Science Investigation of the Sun instrument suite on board NASA's Parker Solar Probe. Background systematic noise is modeled using cross-correlation analysis between different SEP energy channels and subtracted from the original data. The use of these four methods for deriving the time-series persistence allows us to (i) differentiate between …

Optimizing Nitrogen-Fertilizer Management By Using Rzwqm2 With Consideration Of Precipitation Can Enhance Nitrogen Utilization On The Loess Plateau, Dianyuan Ding, Zijie Yang, Lihong Wu, Ying Zhao, Xi Zhang, Xiaoping Chen, Hao Feng, Chao Zhang, Ole Wendroth

Faculty Publications

Crop yields are related to N fertilizer management, and also depend on local precipitation. Varying precipitation levels with long-term meteorological data have not been considered to optimize nitrogen (N) strategies in previous studies on the Loess Plateau of China. In this study, Root Zone Water Quality Model 2 (RZWQM2) was calibrated and validated using data from multi-year experiments and used to assess and optimize N management strategies for winter wheat cultivation. Results showed that the basal dressing fertilizer with 120 kg N ha-1 together with the topdressing of 67–77 kg N ha-1 was recommended in regions with 443 mm average …

Children’S Reading Of Visuals In Informational Picturebooks And Biographies, Sunah Chung

Faculty Publications

Visuals in picturebooks play an important role in supporting children’s reading comprehension and literacy development. This qualitative case study analyzes three American families’ shared reading practices at home by analyzing their online surveys for family literacy environments, reading logs for a month, mother interviews, and video observation of their shared reading at home. The analysis of the collected data categorizes children’s responses to visuals into three major themes: reflecting personal preferences and thoughts on visuals, interpreting visuals based on prior knowledge, and misreading visuals that interfere with understanding content. The discussion focuses on the roles of visuals in informational picturebooks …

Noise In The Library: Using Wearable Biomarker Devices To Measure Student Stress While Studying In The Library, Megan Frost

Faculty Publications

Many patrons come to the library seeking a quite environment, but some library spaces are noisy. In our study, we attempted to identify if the level of noise in a typical busy university library setting impacted the physiological stress of its patrons, as measured by wearable devices. We assessed participants’ heart rate variability (HRV) and skin temperature while they studied in different areas in the library. We found that there was no significant difference in patron stress levels while studying in loud vs quiet areas. This was even true for those patrons who came into the library hoping to be …

The Fate Of Fixed Nitrogen In Santa Barbara Basin Sediments During Seasonal Anoxia, Xuefeng Peng, David J. Yousavich, Annie Bourbonnais, Frank Wenzhöfer, Felix Janssen, Tina Treude, David L. Valentine

Faculty Publications

Despite long-standing interest in the biogeochemistry of the Santa Barbara Basin (SBB), there are no direct rate measurements of different nitrogen transformation processes. We investigated benthic nitrogen cycling using in situ incubations with ¹⁵NO ₃̅  addition and quantified the rates of total nitrate (NO ₃̅) uptake, denitrification, anaerobic ammonia oxidation (anammox), N₂O production, and dissimilatory nitrate reduction to ammonia (DNRA). Denitrification was the dominant NO ₃̅ reduction process, while anammox contributed 0 %–27 % to total NO ₃̅ reduction. DNRA accounted for less than half of NO ₃̅ reduction except at the …

The Ring-Closing Reaction Of Cyclopentadiene Probed With Ultrafast X-Ray Scattering, Lisa Huang, Lauren Bertram, Lingyu Ma, Nathan Goff, Stuart W. Crane, Asami Odate, Thomas Northey, Andrés Moreno Carrascosa, Mats Simmermacher, Sri Bhavya Muvva, Joseph D. Geiser, Matthew J. Lueckheide, Zane Phelps, Mengning Liang, Xinxin Cheng, Ruaridh Forbes, Joseph S. Robinson, Matthew J. Hayes, Felix Allum, Alice E. Green, Kenneth Lopata, Artem Rudenko, Thomas J.A. Wolf, Martin Centurion, Daniel Rolles, Michael P. Minitti, Adam Kirrander, Peter M. Weber

Faculty Publications

The dynamics of cyclopentadiene (CP) following optical excitation at 243 nm was investigated by time-resolved pump-probe X-ray scattering using 16.2 keV X-rays at the Linac Coherent Light Source (LCLS). We present the first ultrafast structural evidence that the reaction leads directly to the formation of bicyclo[2.1.0]pentene (BP), a strained molecule with three- and four-membered rings. The bicyclic compound decays via a thermal backreaction to the vibrationally hot CP with a time constant of 21 ± 3 ps. A minor channel leads to ring-opened structures on a subpicosecond time scale.

Cultivating A Digital Environment To Support Primary Source Instruction, Lindsey Memory, Rebecca A. Wiederhold, Abby Beazer, Gregory K. Seppi

Faculty Publications

Primary source literacy continues to be a priority for academic institutions. A growing subtopic is digital primary sources and their unique role in pedagogy. Digital primary sources have the capacity to represent more diverse voices, and their digital nature provides greater accessibility to new and existing user populations who cannot always come to the reading room. Digital primary sources can better meet a variety of needs through ADA-compliant transcription, 24/7 access, portability, and extensibility. With that vision in mind, these projects and materials present their own challenges to archivists, librarians, and other instructors seeking to expand these items’ curricular use. …

Correction: Graph Theory And Graph Neural Network Assisted High-Throughput Crystal Structure Prediction And Screening For Energy Conversion And Storage, Joshua Ojih, Mohammed Al-Fahdi, Yagang Yao, Jianjun Hu, Ming Hu

Faculty Publications

Correction for ‘Graph theory and graph neural network assisted high-throughput crystal structure prediction and screening for energy conversion and storage’ by Joshua Ojih et al., J. Mater. Chem. A, 2024, 12, 8502–8515, https://doi.org/10.1039/D3TA06190F.

On page 8511 in section 3.2 of the published article, the text “The single values of bonding and antibonding for each structure are obtained by performing integration over COHP curves for each atomic pair as evaluated by the LOBSTER package” should have included citations to six references. The missing references are listed below as ref. 1–6.

The Royal Society of Chemistry apologises for …

Probabilistic Estimation Of Cadence And Walking Speed From Floor Vibrations, Yohanna Mejiacruz, Juan M. Caicedo, Zhaoshuo Jiang, Jean M. Franco

Faculty Publications

Objective: This research aims to extract human gait parameters from floor vibrations. The proposed approach provides an innovative methodology on occupant activity, contributing to a broader understanding of how human movements interact within their built environment. Methods and Procedures: A multilevel probabilistic model was developed to estimate cadence and walking speed through the analysis of floor vibrations induced by walking. The model addresses challenges related to missing or incomplete information in the floor acceleration signals. Following the Bayesian Analysis Reporting Guidelines (BARG) for reproducibility, the model was evaluated through twenty-seven walking experiments, capturing floor vibration and data from Ambulatory Parkinson’s …

Psychometric Properties Of The Modified Parenting Attitudes Measure Among African American Adolescents In Public Housing, Melissa L. Villodas, Andrew Foell, Lisa C. Smith, Mansoo Yu, Henrika Mccoy, Yibin Yang, Ngozi V. Enelamah, Margaret Lombe, Von Nebbitt

Faculty Publications

Valid and reliable measurements reflecting how perceived maternal and paternal parenting practices are similar, different, complementary, or additive in studying youth outcomes are critical for building knowledge on supportive parenting practices for African American youth living in public housing. We examined the psychometric properties of the Parental Attitudes Measure (PAM) which focuses on youths’ attitudes on parenting practices. Data was collected from the perspective of 660 African American youth living in urban public housing across three cities in the northeast and mid-Atlantic region in the United States. Youth reported on their attitudes about maternal and paternal caregivers. Reliability was determined …

Psychometric Properties Of The Modified Parenting Attitudes Measure Among African American Adolescents In Public Housing, Melissa L. Villodas, Andrew Foell, Lisa C. Smith, Mansoo Yu, Henrika Mccoy, Yibin Yang, Ngozi V. Enelamah, Margaret Lombe, Von Nebbitt

Faculty Publications

Valid and reliable measurements reflecting how perceived maternal and paternal parenting practices are similar, different, complementary, or additive in studying youth outcomes are critical for building knowledge on supportive parenting practices for African American youth living in public housing. We examined the psychometric properties of the Parental Attitudes Measure (PAM) which focuses on youths’ attitudes on parenting practices. Data was collected from the perspective of 660 African American youth living in urban public housing across three cities in the northeast and mid-Atlantic region in the United States. Youth reported on their attitudes about maternal and paternal caregivers. Reliability was determined …

A Multivariate Statistical Approach For Mineral Geographic Provenance Determination Using Laser-Induced Breakdown Spectroscopy And Electron Microprobe Chemical Data: A Case Study Of Copper-Bearing Tourmalines, Barbara L. Dutrow, Nancy J. Mcmillan, Darrell J. Henry

Faculty Publications

The geographic provenance of minerals provides key insights into a range of geologic problems, including the source of gem materials. The tourmaline supergroup is unparalleled in its ability to record and preserve extensive chemical signatures of its formational environment. To evaluate the likelihood that tourmalines of similar compositions from separate geographic localities could be differentiated, a multivariate statistical approach has been utilized on two complementary data sets. These chemical analytical data sets of copper-bearing "Paraiba"tourmaline include data sets acquired with Laser Induced Breakdown Spectroscopy (LIBS) and electron microprobe analysis (EMPA). Fifty-four samples of copper-bearing tourmalines from known source locations from …

A First Step Towards Understanding Thermomechanical Behavior Of The Nb-Cr System Through Interatomic Potential Development And Molecular Dynamics Simulations, Lucas A. Heaton, Adib J. Samin

Faculty Publications

Utilizing a preliminary interatomic potential, this work represents an initial exploration into the thermomechanical behavior of NbCr solid solutions. Specifically, it examines the effect of different amounts of Cr solute, for which information in the literature is limited. The employed interatomic potential was developed according to the embedded atom model (EAM), and was trained on data derived from density functional theory calculations. While the potential demonstrated reasonable accuracy and predictive power when tested, various results highlight deficiencies and encourage further development and training. Mechanical strength, heat capacities, thermal expansion coefficients, and thermal conductivities were found to decrease with Cr content. …

High-Speed Two-Color Scanning Volumetric Laser-Induced Fluorescence, Diego Tapia Silva, Cole J. Cooper, Tracy L. Mandel, Shilpa Khatri, Dustin Kleckner

Faculty Publications

Many problems in fluid mechanics require single-shot 3D measurements of fluid flows, but are limited by available techniques. Here, we design and build a novel flexible high-speed two-color scanning volumetric laser-induced fluorescence (H2C-SVLIF) technique. The technique is readily adaptable to a range of temporal and spatial resolutions, rendering it easily applicable to a wide spectrum of experiments. The core equipment consists of a single monochrome high-speed camera and a pair of ND: YAG lasers pulsing at different wavelengths. The use of a single camera for direct 3D imaging eliminates the need for complex volume reconstruction algorithms and easily allows for …

High-Speed Two-Color Scanning Volumetric Laser-Induced Fluorescence, Diego Tapia Silva, Cole J. Cooper, Tracy L. Mandel, Shilpa Khatri, Dustin Kleckner

Faculty Publications

Many problems in fluid mechanics require single-shot 3D measurements of fluid flows, but are limited by available techniques. Here, we design and build a novel flexible high-speed two-color scanning volumetric laser-induced fluorescence (H2C-SVLIF) technique. The technique is readily adaptable to a range of temporal and spatial resolutions, rendering it easily applicable to a wide spectrum of experiments. The core equipment consists of a single monochrome high-speed camera and a pair of ND: YAG lasers pulsing at different wavelengths. The use of a single camera for direct 3D imaging eliminates the need for complex volume reconstruction algorithms and easily allows for …

Moving Slow And Fixing Things, Hannibal Travis

Faculty Publications

No abstract provided.

Birefringence Tests Of Gravity With Multimessenger Binaries, Macarena Lagos, Leah Jenks, Maximiliano Isi, Kenta Hotokezaka, Brian D. Metzger, Eric Burns, Will M. Farr, Scott Perkins, Kaze W.K. Wong, Nicolás Yunes

Faculty Publications

Extensions to general relativity allow the polarization of gravitational waves (GW) from astrophysical sources to suffer from amplitude and velocity birefringence, which respectively induce changes in the ellipticity and orientation of the polarization tensor. We introduce a multimessenger approach to test this polarization behavior of GWs during their cosmological propagation using binary sources, for which the initial polarization is determined by the inclination and orientation angles of the orbital angular momentum vector with respect to the line of sight. In particular, we use spatially resolved radio imaging of the jet from a binary neutron star (BNS) merger to constrain the …

Multifunctional Nanoparticles Of Porphyrins And Phthalocyanines: Review Of Synthetic Strategies And Emerging Applications, Olajumoke Helen Olubowale, Quynh Do, Neepa Kuruppu Arachchige, Deja Gabrielle Hebert, Jayne C. Garno

Faculty Publications

There is considerable research interest in the synthesis and characterization of organic-based nanoparticles because of the wide range of nanomaterials that can be designed with useful functional properties. With emerging research in the synthesis of organic nanoparticles comprised of porphyrins and phthalocyanines, there is a challenge to prepare multifunctional nanoparticles with the desired properties, size, and composition that are stable in environments that are exposed to stresses of pH, oxidation, or heat. This review describes innovative strategies that have been reported for synthesizing nanoparticles of porphyrins and phthalocyanines for applications. The tunability of the structure of porphyrinoid molecules through synthetic …

Short- And Medium-Term Impacts Of Small-Scale Vegetable Support On Food Security: Evidence From Syria, Ghassan Baliki, Melodie Al Daccache, Hala Ghattas Ph.D., Tilman Brück

Faculty Publications

Small-scale agricultural and horticultural interventions play a critical role in improving nutrition and food security of vulnerable households in peaceful settings. However, scant rigorous evidence exists on the impacts and sustainability of such interventions in conflict settings. In this paper, we address this knowledge gap by analyzing the short- and medium-term impacts of a small-scale vegetable input support program involving asset transfers on food security and diets in war-time Syria. We use longitudinal panel household survey data from a quasi-experimental study collected at three rounds: before, one year, and two years after the horticultural intervention ended. We use propensity score …

Incorporating Oxygen Isotopes Of Oxidized Reactive Nitrogen In The Regional Atmospheric Chemistry Mechanism, Version 2 (Icoin-Racm2), Wendell W. Walter, Masayuki Takeuchi, Nga L. Ng, Meredith G. Hastings

Faculty Publications

The oxygen isotope anomaly (Δ¹⁷O = δ¹⁷O − 0.52 × δ¹⁸O > 0) has proven to be a robust tool for probing photochemical cycling and atmospheric formation pathways of oxidized reactive nitrogen (NO_y). Several studies have developed modeling techniques to implicitly model Δ¹⁷O of NO_y molecules based on numerous assumptions that may not always be valid. Thus, these models may be oversimplified and limit our ability to compare model Δ¹⁷O values of NO_y with observations. In this work, we introduce a novel method for explicitly tracking Δ …

A Microfluidic Approach To Study Variations In Chlamydomonas Reinhardtii Alkaline Phosphatase Activity In Response To Phosphate Availability, Alireza Rahnama, Manibarathi Vaithiyanathan, Luis Briceno-Mena, Travis M. Dugas, Kelly L. Yates, Jose A. Romagnoli, Adam T. Melvin

Faculty Publications

Algal growth depends strongly on phosphorus (P) as a key nutrient, underscoring the significance of monitoring P levels. Algal species display a sensitive response to fluctuations in P availability, notably through the expression of alkaline phosphatase (AP) when challenged with P-depletion. As such, alkaline phosphatase activity (APA) serves as a valuable metric for P availability, offering insights into how algae utilize and fix available P resources. However, current APA quantification methods lack single cell resolution, while also being time- and reagent consuming. Microfluidics offers a promising cost-effective solution to these limitations, providing a platform for precise single-cell analysis. In this …

Electrochemical Identification Of Metal Chlorides In Eutectic Licl-Kcl Without Prior Knowledge Of Analyte Identities, Tyler Williams, Jason Torrie, Mark Schvaneveldt, Ranon Fuller, Greg Chipman, Devin Rappleye

Faculty Publications

The identities of unknown analytes within four eutectic LiCl-KCl melts were determined using electrochemical methods, simulating the uncertainty of electrochemically probing an electrorefiner salt bath or molten salt nuclear reactor. With a variety of electrochemical methods (e.g. cyclic voltammetry, chronopotentiometry, and square-wave voltammetry), and electroanalytical techniques (e.g. semi-differentiation), every analyte was positively identified, although one false positive occurred because of an unexpected chemical interaction. This study highlights some remaining challenges for the use of electrochemical sensors in nuclear material control and accountability in molten salts: (1) quantification of analytes without the use of calibration curves (e.g. error in property values, …