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Full-Text Articles in Physical Sciences and Mathematics

Oer Ellipses And Traditional Rapanui Houses On Easter Island, Cynthia Huffman Ph.D. Dec 2020

Oer Ellipses And Traditional Rapanui Houses On Easter Island, Cynthia Huffman Ph.D.

Faculty Submissions

This worksheet activity is appropriate for secondary students in a class studying conic sections or students in a college algebra class. The first part of the activity gives an algebraic review of ellipses with exercises while the second part finds the equation of an ellipse corresponding to a Rapanui boat house foundation.


A Predictive Analytics Approach To Building A Decision Support System For Improving Graduation Rates At A Four-Year College, Xuan Wang, Helmut Schneider, Kenneth R. Walsh Dec 2020

A Predictive Analytics Approach To Building A Decision Support System For Improving Graduation Rates At A Four-Year College, Xuan Wang, Helmut Schneider, Kenneth R. Walsh

Information Systems Faculty Publications and Presentations

Although graduation rates have interested stakeholders, educational researchers, and policymakers for some time, little progress has been made on the overall graduation rate at four-year state colleges. Even though selective admission based on academic indicators such as high school GPA and ACT/ SAT have widely been used in the USA for years, and recent statistics show that less than 40% of students graduate from four-year state colleges in four years in the US. The authors propose using an ensemble of analytic models that considers cost as a better form of analysis that can be used as input to decision support …


Spatial And Temporal Variability Of Carbonaceous Aerosol Absorption In The Po Valley, Stefania Gilardoni, Paola Massoli, Angela Marinoni, Claudio Mazzoleni, Andrew Freedman, Giovanni Lonati, Silvana De Iuliis, Vorne Gianelle Dec 2020

Spatial And Temporal Variability Of Carbonaceous Aerosol Absorption In The Po Valley, Stefania Gilardoni, Paola Massoli, Angela Marinoni, Claudio Mazzoleni, Andrew Freedman, Giovanni Lonati, Silvana De Iuliis, Vorne Gianelle

Michigan Tech Publications

Knowledge gaps in the optical properties of carbonaceous aerosols account for a significant fraction of the uncertainty of aerosol-light interactions in climate models. Both black carbon (BC) and brown carbon (BrC) can display a range of optical properties in ambient aerosol due to different sources and chemical transformation pathways. This study investigates the optical absorption properties of BC and BrC at an urban and a rural site in the Po Valley (Italy), a known European pollution hot spot. We observed spatial and seasonal variability of aerosol absorption coefficients, with the highest values measured in winter at the urban site of …


Bioconversion Of Industrial Hemp Biomass For Bioethanol Production: A Review, Jikai Zhao, Youjie Xu, Weiqun Wang, Jason Griffin, Kraig Roozeboom, Donghai Wang Dec 2020

Bioconversion Of Industrial Hemp Biomass For Bioethanol Production: A Review, Jikai Zhao, Youjie Xu, Weiqun Wang, Jason Griffin, Kraig Roozeboom, Donghai Wang

School of Earth, Environmental, and Marine Sciences Faculty Publications and Presentations

Industrial hemp (Cannabis sativa L.) with robust drought-resistant features has excellent agronomic and pharmaceutical characteristics. As the federal prohibition on hemp cultivation was lifted, its valorization in various aspects is highly required. This review aims to summarize the potential of hemp biomass for bioethanol production. Chemical compositions of hemp biomass were evaluated as compared with those of corn fiber, corn stover, and sorghum bagasse. Several representative pretreatment technologies used for hemp biomass were summarized in terms of sugar recoveries, lignin removal, and sugar and ethanol yields. This review presents numerous technical barriers attributed to insufficient fermentable sugar and ethanol …


Politeness In Security Directives: Insights In Browser Compliance For The Human Element, Deanna House, Gabe Giordano Dec 2020

Politeness In Security Directives: Insights In Browser Compliance For The Human Element, Deanna House, Gabe Giordano

Information Systems and Quantitative Analysis Faculty Publications

The technical protection provided by information security technology is necessary as a frontline defense against threats. However, the human element adds great risk to systems and cannot be ignored. This research explores the human elements related to security communications and intention to comply with security directives. Security communications are more-commonly being sent using richer computer-based channels. While the goal of security communications is the gain compliance, there is still much to learn related to what influences a user to comply. This research explores the effects that (im)politeness has on intention to comply with security directives. The research utilized an experiment …


3-D Fabry–Pérot Cavities Sculpted On Fiber Tips Using A Multiphoton Polymerization Process, Jonathan W. Smith, Jeremiah C. Williams, Joseph S. Suelzer, Nicholas G. Usechak, Hengky Chandrahalim Dec 2020

3-D Fabry–Pérot Cavities Sculpted On Fiber Tips Using A Multiphoton Polymerization Process, Jonathan W. Smith, Jeremiah C. Williams, Joseph S. Suelzer, Nicholas G. Usechak, Hengky Chandrahalim

Faculty Publications

This paper presents 3-D Fabry–Pérot (FP) cavities fabricated directly onto cleaved ends of low-loss optical fibers by a two-photon polymerization (2PP) process. This fabrication technique is quick, simple, and inexpensive compared to planar microfabrication processes, which enables rapid prototyping and the ability to adapt to new requirements. These devices also utilize true 3-D design freedom, facilitating the realization of microscale optical elements with challenging geometries. Three different device types were fabricated and evaluated: an unreleased single-cavity device, a released dual-cavity device, and a released hemispherical mirror dual-cavity device. Each iteration improved the quality of the FP cavity's reflection spectrum. The …


The Surface Diffusion And The Willmore Flow For Uniformly Regular Hypersurfaces, Jeremy Lecrone, Yuanzhen Shao, Gieri Simonett Dec 2020

The Surface Diffusion And The Willmore Flow For Uniformly Regular Hypersurfaces, Jeremy Lecrone, Yuanzhen Shao, Gieri Simonett

Department of Math & Statistics Faculty Publications

We consider the surface diffusion and Willmore flows acting on a general class of (possibly non–compact) hypersurfaces parameterized over a uniformly regular reference manifold possessing a tubular neighborhood with uniform radius. The surface diffusion and Willmore flows each give rise to a fourth–order quasilinear parabolic equation with nonlinear terms satisfying a specific singular structure. We establish well–posedness of both flows for initial surfaces that are C1+α–regular and parameterized over a uniformly regular hypersurface. For the Willmore flow, we also show long–term existence for initial surfaces which are C1+α–close to a sphere, and we prove …


A Set Theory Based Similarity Measure For Text Clustering And Classification, Ali A. Amer, Hassan I. Abdalla Dec 2020

A Set Theory Based Similarity Measure For Text Clustering And Classification, Ali A. Amer, Hassan I. Abdalla

All Works

© 2020, The Author(s). Similarity measures have long been utilized in information retrieval and machine learning domains for multi-purposes including text retrieval, text clustering, text summarization, plagiarism detection, and several other text-processing applications. However, the problem with these measures is that, until recently, there has never been one single measure recorded to be highly effective and efficient at the same time. Thus, the quest for an efficient and effective similarity measure is still an open-ended challenge. This study, in consequence, introduces a new highly-effective and time-efficient similarity measure for text clustering and classification. Furthermore, the study aims to provide a …


Digital Transformation In Higher Education: A Framework For Maturity Assessment, Adam Marks, Maytha Al-Ali, Reem Atassi, Abedallah Zaid Abualkishik, Yacine Rezgui Dec 2020

Digital Transformation In Higher Education: A Framework For Maturity Assessment, Adam Marks, Maytha Al-Ali, Reem Atassi, Abedallah Zaid Abualkishik, Yacine Rezgui

All Works

© 2020 Science and Information Organization. All rights reserved. —Literature in digital transformation maturity is scarce. Digital transformation in higher education, especially after COVID-19 is seen as inevitable. This research explores digital transformation maturity and challenges within Higher Education. The significance of this study stems from the role digital transformation plays in today’s knowledge economy. This study proposes a new framework based on Deloitte’s 2019 digital transformation assessment framework with Petkovic 2014 mega and major higher education process mapping. The study triangulates the findings of multiple research instruments, including survey, interviews, case study, and direct observation. The research findings show …


Fractional Nonlinear Volterra–Fredholm Integral Equations Involving Atangana–Baleanu Fractional Derivative: Framelet Applications, Mutaz Mohammad, Alexander Trounev Dec 2020

Fractional Nonlinear Volterra–Fredholm Integral Equations Involving Atangana–Baleanu Fractional Derivative: Framelet Applications, Mutaz Mohammad, Alexander Trounev

All Works

© 2020, The Author(s). In this work, we propose a framelet method based on B-spline functions for solving nonlinear Volterra–Fredholm integro-differential equations and by involving Atangana–Baleanu fractional derivative, which can provide a reliable numerical approximation. The framelet systems are generated using the set of B-splines with high vanishing moments. We provide some numerical and graphical evidences to show the efficiency of the proposed method. The obtained numerical results of the proposed method compared with those obtained from CAS wavelets show a great agreement with the exact solution. We confirm that the method achieves accurate, efficient, and robust measurement.


Causal Intervention For Weakly-Supervised Semantic Segmentation, Zhang Dong, Hanwang Zhang, Jinhui Tang, Xian-Sheng Hua, Qianru Sun Dec 2020

Causal Intervention For Weakly-Supervised Semantic Segmentation, Zhang Dong, Hanwang Zhang, Jinhui Tang, Xian-Sheng Hua, Qianru Sun

Research Collection School Of Computing and Information Systems

We present a causal inference framework to improve Weakly-Supervised Semantic Segmentation (WSSS). Specifically, we aim to generate better pixel-level pseudo-masks by using only image-level labels --- the most crucial step in WSSS. We attribute the cause of the ambiguous boundaries of pseudo-masks to the confounding context, e.g., the correct image-level classification of "horse'' and "person'' may be not only due to the recognition of each instance, but also their co-occurrence context, making the model inspection (e.g., CAM) hard to distinguish between the boundaries. Inspired by this, we propose a structural causal model to analyze the causalities among images, contexts, and …


Proving Pairwise Intransitivity In Sets Of Dice, Erika Clary Dec 2020

Proving Pairwise Intransitivity In Sets Of Dice, Erika Clary

Honors Projects

Prior research has been conducted regarding the intransitivity of a set of dice when a single die from a set is rolled against another die from that set and when two of the same dice are rolled against a different pair of two of the same dice. This project examines and proves that an intransitive cycle exists in every set of at least five dice when two different dice are rolled against two other different dice.


The Impact Of The Diabetes Management Incentive On Diabetes-Related Services: Evidence From Ontario, Canada., Thaksha Thavam, Rose Anne Devlin, Amardeep Thind, Gregory S Zaric, Sisira Sarma Dec 2020

The Impact Of The Diabetes Management Incentive On Diabetes-Related Services: Evidence From Ontario, Canada., Thaksha Thavam, Rose Anne Devlin, Amardeep Thind, Gregory S Zaric, Sisira Sarma

Epidemiology and Biostatistics Publications

Financial incentives have been introduced in several countries to improve diabetes management. In Ontario, the most populous province in Canada, a Diabetes Management Incentive (DMI) was introduced to family physicians practicing in patient enrollment models in 2006. This paper examines the impact of the DMI on diabetes-related services provided to individuals with diabetes in Ontario. Longitudinal health administrative data were obtained for adults diagnosed with diabetes and their family physicians. The study population consisted of two groups: DMI group (patients enrolled with a family physician exposed to DMI for 3 years), and comparison group (patients affiliated with a family physician …


Impacts Of Environmental Conditions On Fleas In Black-Tailed Prairie Dog Burrows, Julia E. Poje, Tonie Rocke, Michael D. Samuel Dec 2020

Impacts Of Environmental Conditions On Fleas In Black-Tailed Prairie Dog Burrows, Julia E. Poje, Tonie Rocke, Michael D. Samuel

United States Geological Survey: Staff Publications

Sylvatic plague, caused by the bacterium Yersinia pestis and transmitted by fleas, occurs in prairie dogs of the western United States. Outbreaks can devastate prairie dog communities, often causing nearly 100% mortality. Three competent flea vectors, prairie dog specialists Oropsylla hirsuta and O. tuberculata, and generalist Pulex simulans, are found on prairie dogs and in their burrows. Fleas are affected by climate, which varies across the range of black-tailed prairie dogs (Cynomys ludovicianus), but these effects may be ameliorated somewhat due to the burrowing habits of prairie dogs. Our goal was to assess how temperature and precipitation …


Hole In The Wall Dredge Channel Data Report, C. Scott Hardaway Jr., Donna A. Milligan, Christine A. Wilcox, Nicholas J. Dinapoli Dec 2020

Hole In The Wall Dredge Channel Data Report, C. Scott Hardaway Jr., Donna A. Milligan, Christine A. Wilcox, Nicholas J. Dinapoli

Reports

Hole in the Wall (HITW) is located in Mathews County, Virginia (Figure 1). It is a natural channel between fetch-limited barrier islands that provides access from Chesapeake Bay to Milford Haven and Gwynn Island. Milford Haven is a unique tidal creek watershed occurring between Chesapeake Bay and the Piankatank River and consists of numerous lateral tidal creeks entering from Gwynn Island to the north and others entering from the south including Lanes Creek, Stutts Creek, Billups Creek, Stoakes Creek and Whites Creek (Figure 2). Presently, the barrier between Milford Haven and Chesapeake Bay includes the northern barrier and Rigby Island. …


Teaching Applications And Implications Of Blockchain Via Project-Based Learning: A Case Study, Kevin Mentzer, Mark Frydenberg, David J. Yates Dec 2020

Teaching Applications And Implications Of Blockchain Via Project-Based Learning: A Case Study, Kevin Mentzer, Mark Frydenberg, David J. Yates

Information Systems and Analytics Department Faculty Journal Articles

This paper presents student projects analyzing or using blockchain technologies, created by students enrolled in courses dedicated to teaching blockchain, at two different universities during the 2018-2019 academic year. Students explored perceptions related to storing private healthcare information on a blockchain, managing the security of Internet of Things devices, maintaining public governmental records, and creating smart contracts. The course designs, which were centered around project-based learning, include self-regulated learning and peer feedback as ways to improve student learning. Students either wrote a research paper or worked in teams on a programming project to build and deploy a blockchain-based application using …


Hog Island Shore Protection And Habitat Restoration Living Shoreline Project, C. Scott Hardaway Jr., Donna A. Milligan, Christine A. Wilcox, Nicholas J. Dinapoli Dec 2020

Hog Island Shore Protection And Habitat Restoration Living Shoreline Project, C. Scott Hardaway Jr., Donna A. Milligan, Christine A. Wilcox, Nicholas J. Dinapoli

Reports

Hog Island is an emergent estuarine marsh complex that is part of the overall Guinea marshes (Figure 1). These marshes are located at the confluence of Mobjack Bay and the York River in Gloucester County, Virginia. Hog Island is a high wave energy eroding shoreline along its south-face on the York River, and lower wave energy along its west and east flanks that occur on Monday Creek (Figure 2). The marsh consists mainly of grasses such as Spartina alterniflora and Spartina patens. A higher, sandy area along the higher energy shorelines has some scrub shrub. Two small ponds and a …


The Prairie Naturalist, Vol. 52, Issue 2, December 2020 Dec 2020

The Prairie Naturalist, Vol. 52, Issue 2, December 2020

The Prairie Naturalist

Comparing Native Bee Communities on Reconstructed and Remnant Prairie in Missouri • Joseph LaRose, Elisabeth B. Webb, and Deborah Finke

Patterns and Potential Causes of Changing Winter Bird Distributions in South Dakota • David L. Swanson, Reza Goljani Amipkhiz, and Mark D. Dixon

Greater prairie-chickens and sharp-tailed grouse have similarly high nest survival in the Nebraska Sandhills • Larkin A. Powell, Walter H. Schacht, Julia P. Ewalt, and Katie R. McCollum

Captive Ring-necked Pheasant Response to Very High Experimental Doses of Lead • Travis J. Runia and Alex J. Solem

Trends in a Greater Prairie Chicken Population Established by Translocation …


Exploring The Potential Of Defeasible Argumentation For Quantitative Inferences In Real-World Contexts: An Assessment Of Computational Trust, Lucas Rizzo, Pierpaolo Dondio, Luca Longo Dec 2020

Exploring The Potential Of Defeasible Argumentation For Quantitative Inferences In Real-World Contexts: An Assessment Of Computational Trust, Lucas Rizzo, Pierpaolo Dondio, Luca Longo

Articles

Argumentation has recently shown appealing properties for inference under uncertainty and conflicting knowledge. However, there is a lack of studies focused on the examination of its capacity of exploiting real-world knowledge bases for performing quantitative, case-by-case inferences. This study performs an analysis of the inferential capacity of a set of argument-based models, designed by a human reasoner, for the problem of trust assessment. Precisely, these models are exploited using data from Wikipedia, and are aimed at inferring the trustworthiness of its editors. A comparison against non-deductive approaches revealed that these models were superior according to values inferred to recognised trustworthy …


All-Dielectric Magnetic Metasurface For Advanced Light Control In Dual Polarizations Combined With High-Q Resonances, Daria O. Ignatyeva, Dolendra Karki, Andrey A. Voronov, Mikhail A. Kozhaev, Denis M. Krichevsky, Alexander I. Chernov, Miguel Levy, Vladimir I. Belotelov Dec 2020

All-Dielectric Magnetic Metasurface For Advanced Light Control In Dual Polarizations Combined With High-Q Resonances, Daria O. Ignatyeva, Dolendra Karki, Andrey A. Voronov, Mikhail A. Kozhaev, Denis M. Krichevsky, Alexander I. Chernov, Miguel Levy, Vladimir I. Belotelov

Michigan Tech Publications

Nanostructured magnetic materials provide an efficient tool for light manipulation on sub-nanosecond and sub-micron scales, and allow for the observation of the novel effects which are fundamentally impossible in smooth films. For many cases of practical importance, it is vital to observe the magneto-optical intensity modulation in a dual-polarization regime. However, the nanostructures reported on up to date usually utilize a transverse Kerr effect and thus provide light modulation only for p-polarized light. We present a concept of a transparent magnetic metasurface to solve this problem, and demonstrate a novel mechanism for magneto-optical modulation. A 2D array of bismuth-substituted iron-garnet …


Lightgwas: A Novel Machine Learning Procedure For Genome-Wide Association Study, Ambrozio Bruno, Luca Longo, Lucas Rizzo Dec 2020

Lightgwas: A Novel Machine Learning Procedure For Genome-Wide Association Study, Ambrozio Bruno, Luca Longo, Lucas Rizzo

Articles

This paper proposes a novel machine learning procedure for genome-wide association study (GWAS), named LightGWAS. It is based on the LightGBM framework, in addition to being a single, resilient, autonomous and scalable solution to address common limitations of GWAS implementations found in the literature. These include reliance on massive manual quality control steps and specific GWAS methods for each type of dataset morphology and size. Through this research, LightGWAS has been contrasted against PLINK2, one of the current state-of-the-art for GWAS implementations based on general linear model with support to firth regularisation. The mean differences measured upon standard classification metrics, …


Approximating Special Social Influence Maximization Problems, Jie Wu, Ning Wang Dec 2020

Approximating Special Social Influence Maximization Problems, Jie Wu, Ning Wang

Faculty Scholarship for the College of Science & Mathematics

Social Influence Maximization Problems (SIMPs) deal with selecting k seeds in a given Online Social Network (OSN) to maximize the number of eventually-influenced users. This is done by using these seeds based on a given set of influence probabilities among neighbors in the OSN. Although the SIMP has been proved to be NP-hard, it has both submodular (with a natural diminishing-return) and monotone (with an increasing influenced users through propagation) that make the problem suitable for approximation solutions. However, several special SIMPs cannot be modeled as submodular or monotone functions. In this paper, we look at several conditions under which …


Participatory Video As A Novel Recovery-Oriented Intervention In Early Psychosis: A Pilot Study., Arlene G Macdougall, Sahana Kukan, Elizabeth Price, Sarah Glen, Richelle Bird, Laura Powe, Joshua C. Wiener, Paul H Lysaker, Kelly K Anderson, Ross Mg Norman Dec 2020

Participatory Video As A Novel Recovery-Oriented Intervention In Early Psychosis: A Pilot Study., Arlene G Macdougall, Sahana Kukan, Elizabeth Price, Sarah Glen, Richelle Bird, Laura Powe, Joshua C. Wiener, Paul H Lysaker, Kelly K Anderson, Ross Mg Norman

Epidemiology and Biostatistics Publications

BACKGROUND: Personal narrative plays an important role in the process of recovery from psychotic illnesses. Participatory video is a novel, active intervention that can be used as a tool for fostering narrative development among people with psychosis.

AIM: To assess the feasibility, acceptability and potential clinical utility of participatory video as an innovative tool for promoting recovery in early psychosis.

METHODS: Ten outpatients of an early psychosis intervention programme were recruited to participate in 13 biweekly workshops to plan, film and produce documentary-style videos of their experiences. Feasibility was measured through recruitment and retention. Acceptability was measured through workshop attendance …


Thermometry And Microstructural Analysis Imply Protracted Extensional Exhumation Of The Tso Morari Uhp Nappe, Northwestern Himalaya: Implications For Models Of Uhp Exhumation, Sean P. Long, Matthew J. Kohn, Buchanan C. Kerswell, Jesslyn K. Starnes, Kyle P. Larson, Nolan R. Blackford, Emmanuel Soignard Dec 2020

Thermometry And Microstructural Analysis Imply Protracted Extensional Exhumation Of The Tso Morari Uhp Nappe, Northwestern Himalaya: Implications For Models Of Uhp Exhumation, Sean P. Long, Matthew J. Kohn, Buchanan C. Kerswell, Jesslyn K. Starnes, Kyle P. Larson, Nolan R. Blackford, Emmanuel Soignard

Geosciences Faculty Publications and Presentations

Documenting the processes that facilitate exhumation of ultrahigh‐pressure (UHP) rocks at convergent margins is critical for understanding orogen dynamics. Here, we present structural and temperature data from the Himalayan UHP Tso Morari nappe (TMN) and overlying nappes, which we integrate with published pressure‐temperature‐time constraints to refine interpretations for their structural evolution and exhumation history. Our data indicate that the 5.5‐km‐thick TMN is the upper portion of a penetratively deformed ductile slab, which was extruded via distributed, pure shear‐dominated, top‐down‐to‐east shearing. Strain in the TMN is recorded by high‐strength quartz fabrics (density norms between 1.74 and 2.86) and finite strain data …


Structure Analysis Of Natural Wangdaodeite—Linbo3-Type Fetio3, Oliver Tschauner, Chi Ma, Matthew G. Newville, Antonio Lanzirotti Dec 2020

Structure Analysis Of Natural Wangdaodeite—Linbo3-Type Fetio3, Oliver Tschauner, Chi Ma, Matthew G. Newville, Antonio Lanzirotti

Geoscience Faculty Research

© 2020 by the authors. Licensee MDPI, Basel, Switzerland. This paper reports the first structure refinement of natural wangdaodeite, LiNbO3-type FeTiO3 from the Ries impact structure. Wangdaodeite occurs together with recrystallized ilmenite clasts in shock melt veins which have experienced peak shock pressures of between 17 and 22 GPa. Comparison of natural and synthetic wangdaodeite points toward a correlation between the distortion of ferrate-and titanate-polyhedra and the c/a ratio of the unit cell. The Raman spectrum of wangdaodeite is calculated based on the refined structure. Comparison to the reported spectrum of the type-material shows that the Raman peak at 738–740 …


P450 Cyp17a1 Variant With A Disordered Proton Shuttle Assembly Retains Peroxo-Mediated Lyase Efficiency, Yilin Liu, Ilia G. Denisov, Yelena V. Grinkova, Stephen G. Silgar, James R. Kincaid Dec 2020

P450 Cyp17a1 Variant With A Disordered Proton Shuttle Assembly Retains Peroxo-Mediated Lyase Efficiency, Yilin Liu, Ilia G. Denisov, Yelena V. Grinkova, Stephen G. Silgar, James R. Kincaid

Chemistry Faculty Research and Publications

Human cytochrome P450 CYP17A1 first catalyzes hydroxylation at the C17 position of either pregnenolone (PREG) or progesterone (PROG), and a subsequent C17−C20 bond scission to produce dehydroepiandrosterone (DHEA) or androstenedione (AD). In the T306A mutant, replacement of the Threonine 306 alcohol functionality, essential for efficient proton delivery in the hydroxylase reaction, has only a small effect on the lyase activity. In this work, resonance Raman spectroscopy is employed to provide crucial structural insight, confirming that this mutant, with its disordered proton shuttle, fails to generate essential hydroxylase pathway intermediates, accounting for the loss in hydroxylase efficiency. Significantly, …


Neurophysiological Correlates Of Dual Tasking In People With Parkinson's Disease And Freezing Of Gait, Conor Fearon, John Butler, Saskia Waechter, Isabelle Killane, Simon Kelly, Richard B Reilly, Timothy Lynch Dec 2020

Neurophysiological Correlates Of Dual Tasking In People With Parkinson's Disease And Freezing Of Gait, Conor Fearon, John Butler, Saskia Waechter, Isabelle Killane, Simon Kelly, Richard B Reilly, Timothy Lynch

Articles

Freezing of gait in people with Parkinson's disease (PwP) is associated with executive dysfunction and motor preparation deficits. We have recently shown that electrophysiological markers of motor preparation, rather than decision-making, differentiate PwP with freezing of gait (FOG +) and without (FOG -) while sitting. To examine the effect of locomotion on these results, we measured behavioural and electrophysiological responses in PwP with and without FOG during a target response time task while sitting (single-task) and stepping-in-place (dual-task). Behavioural and electroencephalographic data were acquired from 18 PwP (eight FOG +) and seven young controls performing the task while sitting and …


A Comparative Analysis Of Rule-Based, Model-Agnostic Methods For Explainable Artificial Intelligence, Giulia Vilone, Lucas Rizzo, Luca Longo Dec 2020

A Comparative Analysis Of Rule-Based, Model-Agnostic Methods For Explainable Artificial Intelligence, Giulia Vilone, Lucas Rizzo, Luca Longo

Articles

The ultimate goal of Explainable Artificial Intelligence is to build models that possess both high accuracy and degree of explainability. Understanding the inferences of such models can be seen as a process that discloses the relationships between their input and output. These relationships can be represented as a set of inference rules which are usually not explicit within a model. Scholars have proposed several methods for extracting rules from data-driven machine-learned models. However, limited work exists on their comparison. This study proposes a novel comparative approach to evaluate and compare the rulesets produced by four post-hoc rule extractors by employing …


Nonlinear Multigrid Based On Local Spectral Coarsening For Heterogeneous Diffusion Problems, Chak Shing Lee, Francois Hamon, Nicola Castelletto, Panayot S. Vassilevski, Joshua A. White Dec 2020

Nonlinear Multigrid Based On Local Spectral Coarsening For Heterogeneous Diffusion Problems, Chak Shing Lee, Francois Hamon, Nicola Castelletto, Panayot S. Vassilevski, Joshua A. White

Mathematics and Statistics Faculty Publications and Presentations

This work develops a nonlinear multigrid method for diffusion problems discretized by cell-centered finite volume methods on general unstructured grids. The multigrid hierarchy is constructed algebraically using aggregation of degrees of freedom and spectral decomposition of reference linear operators associated with the aggregates. For rapid convergence, it is important that the resulting coarse spaces have good approximation properties. In our approach, the approximation quality can be directly improved by including more spectral degrees of freedom in the coarsening process. Further, by exploiting local coarsening and a piecewise-constant approximation when evaluating the nonlinear component, the coarse level problems are assembled and …


Transfer-To-Transfer Learning Approach For Computer Aided Detection Of Covid-19 In Chest Radiographs, Barath Narayanan Narayanan, Russell C. Hardie, Vignesh Krishnaraja, Christina Karam, Venkata Salini Priyamvada Davuluru Dec 2020

Transfer-To-Transfer Learning Approach For Computer Aided Detection Of Covid-19 In Chest Radiographs, Barath Narayanan Narayanan, Russell C. Hardie, Vignesh Krishnaraja, Christina Karam, Venkata Salini Priyamvada Davuluru

Electrical and Computer Engineering Faculty Publications

The coronavirus disease 2019 (COVID-19) global pandemic has severely impacted lives across the globe. Respiratory disorders in COVID-19 patients are caused by lung opacities similar to viral pneumonia. A Computer-Aided Detection (CAD) system for the detection of COVID-19 using chest radiographs would provide a second opinion for radiologists. For this research, we utilize publicly available datasets that have been marked by radiologists into two-classes (COVID-19 and non-COVID-19). We address the class imbalance problem associated with the training dataset by proposing a novel transfer-to-transfer learning approach, where we break a highly imbalanced training dataset into a group of balanced mini-sets and …