Digital Commons Network^™

Neural Network Repair With Reachability Analysis, Xiaodong Yang, Tom Yamaguchi, Tran Hoang-Dung, Bardh Hoxha, Taylor T. Johnson, Danil Prokhorov

School of Computing: Faculty Publications

Safety is a critical concern for the next generation of autonomy that is likely to rely heavily on deep neural networks for perception and control. Formally verifying the safety and robustness of well-trained DNNs and learning-enabled cyber-physical systems (Le-CPS) under adversarial attacks, model uncertainties, and sensing errors is essential for safe autonomy. This research proposes a framework to repair unsafe DNNs in safety-critical systems with reachability analysis. The repair process is inspired by adversarial training which has demonstrated high effectiveness in improving the safety and robustness of DNNs. Different from traditional adversarial training approaches where adversarial examples are utilized from …

The Effects Of Estradiol-17Β On The Sex Reversal, Survival, And Growth Of Green Sunfish Lepomis Cyanellus, Chad N. Teal, Daniel J. Schill, Susan B. Fogelson, Colby M. Roberts, Kevin Fitzsimmons, Javan M. Bauder, William T. Stewart, Scott A. Bonar

United States Geological Survey: Staff Publications

The feminization of green sunfish Lepomis cyanellus could expand their utility as a game fish or aquacultured species by preventing overcrowding and precocious reproduction in stocked systems. Feminization of green sunfish could also help elucidate information on their sex determination system. We report the feminization of green sunfish cohorts via oral administration of estradiol-17β (E2) during early development. A low-dose (100 E2 mg per kg of diet) and a high-dose (150 E2 mg per kg of diet) experimental E2 treatment were fed to juvenile green sunfish from 30 to 90 days post-hatch. Fish were subsequently evaluated for any treatment effect …

Different Gut Microbiomes Of Developmental Stages Of Field-Collected Native And Invasive Western Bean Cutworm, Striacosta Albicosta, In Western Nebraska, Paul A. Ayayee, Austin Currie, Julie A. Peterson

Department of Entomology: Faculty Publications

While insects harbor gut microbial associates that perform various functions for the host, lepidopterans have not been considered as prime examples of having such relationships. The western bean cutworm, Striacosta albicosta (Lepidoptera: Noctuidae), is native to North America and has historically been a significant corn pest in its western distribution. It is currently expanding eastwards and is invasive in these new regions. Using 16S rRNA gene sequencing data, this study focused on characterizing the microbiota associated with field-collected eggs, larvae, adults, and host plant materials of S. albicosta in its native range. The diversity of microbiomes varied significantly among S. …

Search For A W' Boson Decaying To A Vector-Like Quark And A Top Or Bottom Quark In The All-Jets Final State At √S = 13 Tev, The Cms Collaboration

Department of Physics and Astronomy: Faculty Publications

A search is presented for a heavy W0 boson resonance decaying to a B or T vector-like quark and a t or a b quark, respectively. The analysis is performed using protonproton collisions collected with the CMS detector at the LHC. The data correspond to an integrated luminosity of 138 fb⁻¹ at a center-of-mass energy of 13TeV. Both decay channels result in a signature with a t quark, a Higgs or Z boson, and a b quark, each produced with a significant Lorentz boost. The all-hadronic decays of the Higgs or Z boson and of the t quark are …

Climate Change Alters Aging Patterns Of Reservoir Aquatic Habitats, Leandro E. Miranda, Nicky M. Faucheux

United States Geological Survey: Staff Publications

Two slow-moving developments are threatening reservoir aquatic habitats globally: aging and climate change. These events are projected to transform reservoir aquatic habitats in various and often unpredictable ways. Aging affects in-lake habitats directly, whereas climate change affects both in-lake and off-lake conditions. Climate change is expected to accelerate and, in some instances, possibly decelerate aging. Aging can be indexed as functional age, an index that signals the position of a reservoir along its lifespan relying on inlake descriptors of aquatic habitat. Using existing habitat datasets and climate projections, we developed semi-quantitative predictions about the effect of climate change on reservoir …

Sediment Source Fingerprinting As An Aid To Large-Scale Landscape Conservation And Restoration: A Review For The Mississippi River Basin, Zhen Xu, Patrick Belmont, Janice Brahney, Allen C. Gellis

United States Geological Survey: Staff Publications

Reliable quantitative information on sediment sources to rivers is critical to mitigate contamination and target conservation and restoration actions. However, for large-scale river basins, determination of the relative importance of sediment sources is complicated by spatiotemporal variability in erosional processes and sediment sources, heterogeneity in sediment transport and deposition, and a paucity of sediment monitoring data. Sediment source fingerprinting is an increasingly adopted field-based technique that identifies the nature and relative source contribution of sediment transported in waterways. Notably, sediment source fingerprinting provides information that is independent of other field, modeling, or remotely sensed techniques. However, the diversity in sampling, …

Pitfalls And Guidelines For Using Time-Based Git Data, Samuel W. Flint, Jigyasa Chauhan, Robert Dyer

School of Computing: Faculty Publications

Many software engineering research papers rely on time-based data (e.g., commit timestamps, issue report creation/update/close dates, release dates). Like most real-world data however, time-based data is often dirty. To date, there are no studies that quantify how frequently such data is used by the software engineering research community, or investigate sources of and quantify how often such data is dirty. Depending on the research task and method used, including such dirty data could aect the research results. This paper presents an extended survey of papers that utilize time-based data, published in the Mining Software Repositories (MSR) conference series. Out of …

Decipherment Challenges Due To Tamga And Letter Mix-Ups In An Old Hungarian Runic Inscription From The Altai Mountains, Peter Revesz

School of Computing: Faculty Publications

An Old Hungarian Runic inscription from the Altai Mountains with 40 signs has posed some special challenges for decipherment due to several letter mix-ups and the use of a tamga sign, which is the first reported use of a tamga within this type of script. This paper gives a complete and correct translation and draws some lessons that can be learned about decipherment. It introduces sign similarity matrices as a method of detecting accidental misspellings and shows that sign similarity matrices can be efficiently computed. It also explains the importance of simultaneously achieving the three criteria for a valid decipherment: …

Leptogenesis Triggered By A First-Order Phase Transition, Peisi Huang, Ke-Pan Xie

Department of Physics and Astronomy: Faculty Publications

We propose a new scenario of leptogenesis, which is triggered by a first-order phase transition (FOPT). The right-handed neutrinos (RHNs) are massless in the old vacuum, while they acquire a mass in the new vacuum bubbles, and the mass gap is huge compared with the FOPT temperature. The ultra-relativistic bubble walls sweep the RHNs into the bubbles, where the RHNs experience fast decay and generate the lepton asymmetry, which is further converted to the baryon asymmetry of the Universe (BAU). Since the RHNs are out of equilibrium inside the bubble, the generated BAU does not suffer from the thermal bath …

Polarization Topology At The Nominally Charged Domain Walls In Uniaxial Ferroelectrics, Yurii Tikhonov, Jesi R. Maguire, Conor J. Mccluskey, James P. V. Mcconville, Amit Kumar, Haidong Lu, Dennis Meier, Anna Razumnaya, John Martin Gregg, Alexei Gruverman, Valerii M. Vinokur, Igor Luk’Yanchuk

Department of Physics and Astronomy: Faculty Publications

Ferroelectric domain walls provide a fertile environment for novel materials physics. If a polarization discontinuity arises, it can drive a redistribution of electronic carriers and changes in band structure, which often result in emergent 2D conductivity. If such a discontinuity is not tolerated, then its amelioration usually involves the formation of complex topological patterns, such as flux-closure domains, dipolar vortices, skyrmions, merons, or Hopfions. The degrees of freedom required for the development of such patterns, in which dipolar rotation is a hallmark, are readily found in multiaxial ferroelectrics. In uniaxial ferroelectrics, where only two opposite polar orientations are possible, it …

Using Sentinel-2 Imagery And Machine Learning Algorithms To Assess The Inundation Status Of Nebraska Conservation Easements During 2018–2021, Ligang Zhang, University Of Nebraska-Lincoln, Zhenghong Tang

School of Natural Resources: Faculty Publications

Conservation easements (CEs) play an important role in the provision of ecological services. This paper aims to use the open-access Sentinel-2 satellites to advance existing conservation management capacity to a new level of near-real-time monitoring and assessment for the conservation easements in Nebraska. This research uses machine learning and Google Earth Engine to classify inundation status using Sentinel-2 imagery during 2018–2021 for all CE sites in Nebraska, USA. The proposed machine learning approach helps monitor the CE sites at the landscape scale in an efficient and low-cost manner. The results confirmed effective inundation performance in these floodplain or wetland-related CE …

Parasol: Efficient Parallel Synthesis Of Large Model Spaces, Clay Stevens, Hamid Bagheri

School of Computing: Conference and Workshop Papers

Formal analysis is an invaluable tool for software engineers, yet state-of-the-art formal analysis techniques suffer from well-known limitations in terms of scalability. In particular, some software design domains—such as tradeoff analysis and security analysis—require systematic exploration of potentially huge model spaces, which further exacerbates the problem. Despite this present and urgent challenge, few techniques exist to support the systematic exploration of large model spaces. This paper introduces Parasol, an approach and accompanying tool suite, to improve the scalability of large-scale formal model space exploration. Parasol presents a novel parallel model space synthesis approach, backed with unsupervised learning to automatically derive …

Water-Level And Recoverable Water In Storage Changes, High Plains Aquifer, Predevelopment To 2017 And 2015–17, Virginia L. Mcguire, Kellan R. Strauch

United States Geological Survey: Water Reports and Publications

Document abstract

The High Plains aquifer underlies 111.8 million acres (about 175,000 square miles) in parts of eight States—Colorado, Kansas, Nebraska, New Mexico, Oklahoma, South Dakota, Texas, and Wyoming. Water-level declines began in parts of the High Plains aquifer soon after the beginning of substantial groundwater irrigation (about 1950). This report presents water-level changes and change in recoverable water in storage in the High Plains aquifer from predevelopment (about 1950) to 2017 and from 2015 to 2017.

Water-level changes from predevelopment to 2017, by well, ranged from a rise of 84 feet to a decline of 262 feet; the range …

What Makes The Article “Condition Monitoring And Fault Diagnosis Of Electrical Motors—A Review” So Popular?, Wei Qiao

School of Computing: Faculty Publications

Electric motors are widely used in the industrial, commercial, residential, and transportation sectors to power the systems that provide goods and services to end users. The failure of electric motors may cause significant production or service interruption and financial losses. To improve the quality of service of systems driven by electric motors, it is vital to continuously improve the reliability of electric motors. Driven by this demand, various condition monitoring and fault diagnostic techniques for electric motors have been developed by academia and industry over the past decades.

The article “Condition Monitoring and Fault Diagnosis of Electrical Motors—A Review,” written …

Nanomechanical Resonators: Toward Atomic Scale, Bo Xu, Pengcheng Zhang, Jiankai Zhu, Zuheng Liu, Alexander Eichler, Xu-Qian Zheng, Jaesung Lee, Aneesh Dash, Swapnil More, Song Wu, Yanan Wang, Hao Jia, Akshay Naik, Adrian Bachtold, Rui Yang, Philip X.-L. Feng, Zenghui Wang

School of Computing: Faculty Publications

The quest for realizing and manipulating ever smaller man-made movable structures and dynamical machines has spurred tremendous endeavors, led to important discoveries, and inspired researchers to venture to previously unexplored grounds. Scientific feats and technological milestones of miniaturization of mechanical structures have been widely accomplished by advances in machining and sculpturing ever shrinking features out of bulk materials such as silicon. With the flourishing multidisciplinary field of low-dimensional nanomaterials, including one-dimensional (1D) nanowires/nanotubes and two-dimensional (2D) atomic layers such as graphene/ phosphorene, growing interests and sustained effort have been devoted to creating mechanical devices toward the ultimate limit of miniaturization--genuinely …

Estimating The Burden Of Heat-Related Illness Morbidity Attributable To Anthropogenic Climate Change In North Carolina, Jagadeesh Puvvula, Azar M. Abadi, Kathryn C. Conlon, Jared J. Rennie, Stephanie C. Herring, Laurie Thie, Max J. Rudolph, Rebecca Owen, Jesse E. Bell

School of Natural Resources: Faculty Publications

Climate change is known to increase the frequency and intensity of hot days (daily maximum temperature ≥30°C), both globally and locally. Exposure to extreme heat is associated with numerous adverse human health outcomes. This study estimated the burden of heat-related illness (HRI) attributable to anthropogenic climate change in North Carolina physiographic divisions (Coastal and Piedmont) during the summer months from 2011 to 2016. Additionally, assuming intermediate and high greenhouse gas emission scenarios, future HRI morbidity burden attributable to climate change was estimated. The association between daily maximum temperature and the rate of HRI was evaluated using the Generalized Additive Model. …

Permafrost Landscape History Shapes Fluvial Chemistry, Ecosystem Carbon Balance, And Potential Trajectories Of Future Change, Scott Zolkos, Suzanne E. Tank, Steven V. Kokelj, Robert G. Striegl, Sarah Shakil, Carolina Voigt, Oliver Sonnentag, William L. Quinton, Edward A.G. Schuur, Donatella Zona, Peter M. Lafleur, Ryan C. Sullivan, Masahito Ueyama, David Billesbach, David Cook, Elyn R. Humphreys, Philip Marsh

Daugherty Water for Food Global Institute: Faculty Publications

Intensifying permafrost thaw alters carbon cycling by mobilizing large amounts of terrestrial substrate into aquatic ecosystems. Yet, few studies have measured aquatic carbon fluxes and constrained drivers of ecosystem carbon balance across heterogeneous Arctic landscapes. Here, we characterized hydrochemical and landscape controls on fluvial carbon cycling, quantified fluvial carbon fluxes, and estimated fluvial contributions to ecosystem carbon balance across 33 watersheds in four ecoregions in the continuous permafrost zone of the western Canadian Arctic: unglaciated uplands, ice-rich moraine, and organic-rich lowlands and till plains. Major ions, stable isotopes, and carbon speciation and fluxes revealed patterns in carbon cycling across ecoregions …

Combining Phenotypic And Genomic Data To Improve Prediction Of Binary Traits, Diego Jarquin, Arkaprava Roy, Bertrand S. Clarke, Subhashis Ghosal

Department of Statistics: Faculty Publications

Plant breeders want to develop cultivars that outperform existing genotypes. Some characteristics (here ‘main traits’) of these cultivars are categorical and difficult to measure directly. It is important to predict the main trait of newly developed genotypes accurately. In addition to marker data, breeding programs often have information on secondary traits (or ‘phenotypes’) that are easy to measure. Our goal is to improve prediction of main traits with interpretable relations by combining the two data types using variable selection techniques. However, the genomic characteristics can overwhelm the set of secondary traits, so a standard technique may fail to select any …

Project-Based Learning Promotes Students’Perceived Relevance In An Engineering Statistics Course: A Comparison Of Learning In Synchronous And Online Learning Environments, Wen Huang, Jeremi S. London, Loga A. Perry

Department of Civil and Environmental Engineering: Faculty Publications

Understanding statistics is essential for engineers. However, statistics courses remain challenging for many students, as they find them rigid, abstract, and demanding. Prior research has indicated that using project based learning (PjBL) to demonstrate the relevance of statistics to students can have a significant effect on learning in these courses. Consequently, this study sought to explore the impact of a PjBL intervention on student perceptions of the relevance of engineering and statistics. The purpose of the intervention was to help students understand the connection between statistics and their academic majors, lives, and future careers. Four mini-projects connecting statistics to students’ …

Using Electrochemical Oxidation To Remove Pfas In Simulated Investigation-Derivedwaste (Idw): Laboratory And Pilot-Scale Experiments, Amy Yanagida, Elise Webb, Clifford E. Harris, Mark Christenson, Steven Comfort

School of Natural Resources: Faculty Publications

Repeated use of aqueous firefighting foams at military aircraft training centers has contaminated groundwater with per and polyfluorinated alkyl substances (PFAS). To delineate the extent of PFAS contamination, numerous site investigations have occurred, which have generated large quantities of investigation-derived wastes (IDW). The commonly used treatment of incinerating PFAS-tainted IDW is costly, and was recently suspended by the Department of Defense. Given long-term IDW storage in warehouses is not sustainable, our objective was to use electrochemical oxidation to degrade PFAS in contaminated water and then scale the technology toward IDW treatment. This was accomplished by conducting a series of laboratory …

Flint, Michigan Drinking Water Crisis, J. David Aiken

Cornhusker Economics

Briefly covers the Flint, Michigan drinking water crisis including providing some background, a timeline of events, and key takeaways from the perspective of public policy.

This article was originally prepared for distribution to students in Aiken's AECN 357 environmental and natural resources law course.

Computing Rational Powers Of Monomial Ideals, Pratik Dongre, Benjamin Drabkin, Josiah Lim, Ethan Partida, Ethan Roy, Dylan Ruff, Alexandra Seceleanu, Tingting Tang

Department of Mathematics: Faculty Publications

This paper concerns fractional powers of monomial ideals. Rational powers of a monomial ideal generalize the integral closure operation as well as recover the family of symbolic powers. They also highlight many interesting connections to the theory of convex polytopes. We provide multiple algorithms for computing the rational powers of a monomial ideal. We also introduce a mild generalization allowing real powers of monomial ideals. An important result is that given any monomial ideal I, the function taking a real number to the corresponding real power of I is a step function which is left continuous and has rational …

Ai Protein Structure Prediction-Based Modeling And Mutagenesis Of A Protostome Receptor And Peptide Ligands Reveal Key Residues For Their Interaction, Shi-Qi Guo, Ya-Dong Li, Ping Chen, Guo Zhang, Hui-Ying Wang, Hui-Min Jiang, Wei-Jia Liu, Ju-Ping Xu, Xue-Ying Ding, Ping Fu, Ke Yu, Hai-Bo Zhou, James W. Checco, Jian Jing

Department of Chemistry: Faculty Publications

The protostome leucokinin (LK) signaling system, including LK peptides and their G protein-coupled receptors, has been characterized in several species. Despite the progress, molecular mechanisms governing LK peptide–receptor interactions remain to be elucidated. Previously, we identified a precursor protein for Aplysia leucokinin-like peptides (ALKs) that contains the greatest number of amidated peptides among LK precursors in all species identified so far. Here, we identified the first ALK receptor from Aplysia, ALKR. We used cell-based IP1 activation assays to demonstrate that two ALK peptides with the most copies, ALK1 and ALK2, activated ALKR with high potencies. Other endogenous ALK-derived peptides …

Divergent Neural And Endocrine Responses In Wild-Caught And Laboratory-Bred Rattus Norvegicus, Joanna Jacob, Sally Watanabe, Jonathan Richardson, Nick Gonzales, Emily Ploppert, Garet Lahvis, Aaron Shiels, Sadie Wenger, Kelly Saverino, Janhavi Bhalerao, Brendan Crockett, Erin Burns, Olivia Harding, Krista Fischer-Stenger, Kelly Lambert

United States Department of Agriculture Wildlife Services: Staff Publications

Although rodents have represented the most intensely studied animals in neurobiological investigations for more than a century, few studies have systematically compared neural and endocrine differences between wild rodents in their natural habitats and laboratory strains raised in traditional laboratory environments. In the current study, male and female Rattus norvegicus rats were trapped in an urban setting and compared to weight-and sex-matched conspecifics living in standard laboratory housing conditions. Brains were extracted for neural assessments and fecal boli were collected for endocrine [corticosterone and dehydroepiandrosterone (DHEA)] assays. Additionally, given their role in immune and stress functions, spleen and adrenal weights …

Girls In Stem! Elementary Afterschool Six-Week Curriculum, Jess Li, Samavi Rafique

Honors Program: Expanded Learning Clubs

No abstract provided.

Collateral Damage From Agricultural Netting To Open-Country Bird Populations In Thailand, Rongrong Angkaew, Philip D. Round, Dusit Ngoprasert, Larkin A. Powell

School of Natural Resources: Faculty Publications

Nets are used across a wide variety of food production landscapes to control avian pests typically resulting in deaths of entangled birds. However, the impact of nets on bird populations is a human–wildlife conflict that remains mostly unquantified. Here, we examined the scale of netting in the central plains of Thailand, a region dominated by ricefields, among which aquaculture ponds are increasingly interspersed. Nets/exclusion types, number of individual birds and species caught were recorded on 1312 road-survey transects (2-km length × 0.4-km width). We also interviewed 104 local farmers. The transect sampling took place in late- September 2020, and from …

From Free-Energy Profiles To Activation Free Energies, Johannes C. Dietschreit, Dennis J. Diestler, Andreas Hulm, Christian Ochsenfeld, Rafael Gómez-Bombarelli

Department of Agronomy and Horticulture: Faculty Publications

Given a chemical reaction going from reactant (R) to the product (P) on a potential energy surface (PES) and a collective variable (CV) discriminating between R and P, we define the free-energy profile (FEP) as the logarithm of the marginal Boltzmann distribution of the CV. This FEP is not a true free energy. Nevertheless, it is common to treat the FEP as the “free-energy” analog of the minimum potential energy path and to take the activation free energy, ΔF‡ _RP, as the difference between the maximum at the transition state and the minimum at R. We show that this …

Duality For Asymptotic Invariants Of Graded Families, Michael Dipasquale, Thái Thành Nguyễn, Alexandra Seceleanu

Department of Mathematics: Faculty Publications

The starting point of this paper is a duality for sequences of natural numbers which, under mild hypotheses, interchanges subadditive and superadditive sequences and inverts their asymptotic growth constants.

We are motivated to explore this sequence duality since it arises naturally in at least two important algebraic-geometric contexts. The first context is Macaulay- Matlis duality, where the sequence of initial degrees of the family of symbolic powers of a radical ideal is dual to the sequence of Castelnuovo-Mumford regularity values of a quotient by ideals generated by powers of linear forms. This philosophy is drawn from an influential paper of …

Enabling Intelligent Iots For Histopathology Image Analysis Using Convolutional Neural Networks, Mohammed H. Alali, Arman Roohi, Shaahin Angizi, Jitender S. Deogun

School of Computing: Faculty Publications

Medical imaging is an essential data source that has been leveraged worldwide in healthcare systems. In pathology, histopathology images are used for cancer diagnosis, whereas these images are very complex and their analyses by pathologists require large amounts of time and effort. On the other hand, although convolutional neural networks (CNNs) have produced near-human results in image processing tasks, their processing time is becoming longer and they need higher computational power. In this paper, we implement a quantized ResNet model on two histopathology image datasets to optimize the inference power consumption. We analyze classification accuracy, energy estimation, and hardware utilization …

Seasonality Of Precipitation In The Southwestern United States During The Late Pleistocene Inferred From Stable Isotopes In Herbivore Tooth Enamel, Matthew J. Kohn, Kathleen B. Springer, Jeffrey S. Pigati, Linda M. Reynard, Amanda E. Drewicz, Justin Crevier, Eric Scott

United States Geological Survey: Staff Publications

The late Pleistocene was a climatically dynamic period, with abrupt shifts between cool-wet and warmdry conditions. Increased effective precipitation supported large pluvial lakes and long-lived spring ecosystems in valleys and basins throughout the western and southwestern U.S., but the source and seasonality of the increased precipitation are debated. Increases in the proportions of C₄/(C₄+ C₃) grasses in the diets of large grazers have been ascribed both to increases in summer precipitation and lower atmospheric CO₂ levels. Here we present stable carbon and oxygen isotope data from tooth enamel of late Pleistocene herbivores recovered …