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Articles 34171 - 34200 of 302431

Full-Text Articles in Physical Sciences and Mathematics

Noninvasive Detection, Tracking, And Characterization Of Aerogel Implants Using Diagnostic Ultrasound, Sagar Ghimire, Martina Rodriguez Sala, Swetha Chandrasekaran, Grigorios Raptopoulos, Marcus Worsley, Patrina Paraskevopoulou, Nicholas Leventis, Firouzeh Sabri Feb 2022

Noninvasive Detection, Tracking, And Characterization Of Aerogel Implants Using Diagnostic Ultrasound, Sagar Ghimire, Martina Rodriguez Sala, Swetha Chandrasekaran, Grigorios Raptopoulos, Marcus Worsley, Patrina Paraskevopoulou, Nicholas Leventis, Firouzeh Sabri

Chemistry Faculty Research & Creative Works

Medical implants are routinely tracked and monitored using different techniques, such as MRI, X‐ray, and ultrasound. Due to the need for ionizing radiation, the two former methods pose a significant risk to tissue. Ultrasound imaging, however, is non‐invasive and presents no known risk to human tissue. Aerogels are an emerging material with great potential in biomedical implants. While qualitative observation of ultrasound images by experts can already provide a lot of infor-mation about the implants and the surrounding structures, this paper describes the development and study of two simple B‐Mode image analysis techniques based on attenuation measurements and echogenicity comparisons, …


Quadrature For Implicitly-Defined Finite Element Functions On Curvilinear Polygons, Jeffrey S. Ovall, Samuel E. Reynolds Feb 2022

Quadrature For Implicitly-Defined Finite Element Functions On Curvilinear Polygons, Jeffrey S. Ovall, Samuel E. Reynolds

Mathematics and Statistics Faculty Publications and Presentations

Abstract

H1" role="presentation" style="box-sizing: border-box; margin: 0px; padding: 0px; display: inline-block; line-height: normal; font-size: 16.2px; word-spacing: normal; overflow-wrap: normal; white-space: nowrap; float: none; direction: ltr; max-width: none; max-height: none; min-width: 0px; min-height: 0px; border: 0px; position: relative;">H1-conforming Galerkin methods on polygonal meshes such as VEM, BEM-FEM and Trefftz-FEM employ local finite element functions that are implicitly defined as solutions of Poisson problems having polynomial source and boundary data. Recently, such methods have been extended to allow for mesh cells that are curvilinear polygons. Such extensions present new challenges for determining suitable quadratures. We describe an approach …


Volumetric Lattice Boltzmann Method For Wall Stresses Of Image-Based Pulsatile Flows, Xiaoyu Zhang, Joan Gomez-Paz, Xi Chen, James M. Mcdonough, Md Mahfuzul Islam, Yiannis Andreopoulos, Luoding Zhu, Huidan Yu Feb 2022

Volumetric Lattice Boltzmann Method For Wall Stresses Of Image-Based Pulsatile Flows, Xiaoyu Zhang, Joan Gomez-Paz, Xi Chen, James M. Mcdonough, Md Mahfuzul Islam, Yiannis Andreopoulos, Luoding Zhu, Huidan Yu

Mechanical Engineering Faculty Publications

Image-based computational fluid dynamics (CFD) has become a new capability for determining wall stresses of pulsatile flows. However, a computational platform that directly connects image information to pulsatile wall stresses is lacking. Prevailing methods rely on manual crafting of a hodgepodge of multidisciplinary software packages, which is usually laborious and error-prone. We present a new computational platform, to compute wall stresses in image-based pulsatile flows using the volumetric lattice Boltzmann method (VLBM). The novelty includes: (1) a unique image processing to extract flow domain and local wall normality, (2) a seamless connection between image extraction and VLBM, (3) an en-route …


High Harmonic Generation In Mixed Xuv And Nir Fields At A Free-Electron Laser, Jan Troß, Shashank Pathak, Adam Summers, Dimitrios Rompotis, Benjamin Erk, Christopher Passow, Bastian Manschwetus, Rebecca Boll, Patrik Grychtol, Sadia Bari, Vinod Kumarappan, Anh(Anh-Thu) Thu Le, Cheng Jin, Carlos Trallero Feb 2022

High Harmonic Generation In Mixed Xuv And Nir Fields At A Free-Electron Laser, Jan Troß, Shashank Pathak, Adam Summers, Dimitrios Rompotis, Benjamin Erk, Christopher Passow, Bastian Manschwetus, Rebecca Boll, Patrik Grychtol, Sadia Bari, Vinod Kumarappan, Anh(Anh-Thu) Thu Le, Cheng Jin, Carlos Trallero

Physics Faculty Research & Creative Works

We Present the Results of an Experiment Investigating the Generation of High-Order Harmonics by a Femtosecond Near-Infrared (NIR) Laser Pulse in the Presence of an Extreme Ultraviolet (XUV) Field Provided by a Free-Electron Laser (FEL), a Process Referred to as XUV-Assisted High-Order Harmonic Generation (HHG). Our Experimental Findings Show that the XUV Field Can Lead to a Small Enhancement in the Harmonic Yield When the XUV and NIR Pulses overlap in Time, while a Strong Decrease of the HHG Yield and a Red Shift of the HHG Spectrum is Observed When the XUV Precedes the NIR Pulse. the Latter Observations …


Geologic Homogenization, Conditioning, & Reuse, University Of North Dakota. Energy And Environmental Research Center Feb 2022

Geologic Homogenization, Conditioning, & Reuse, University Of North Dakota. Energy And Environmental Research Center

EERC Brochures and Fact Sheets

Fact sheet about the Energy & Environmental Research Center (EERC) project to evaluate the geologic homogenization, conditioning, and reuse (GHCR) concept of water management. Describes the GHCR concept and summarizes results of the multiyear project.


Diagnosis Of Polypoidal Choroidal Vasculopathy From Fluorescein Angiography Using Deep Learning, Yu-Yeh Tsai, Wei-Yang Lin, Shih-Jen Chen, Paisan Ruamviboonsuk, Cheng-Ho King, Chia-Ling Tsai Feb 2022

Diagnosis Of Polypoidal Choroidal Vasculopathy From Fluorescein Angiography Using Deep Learning, Yu-Yeh Tsai, Wei-Yang Lin, Shih-Jen Chen, Paisan Ruamviboonsuk, Cheng-Ho King, Chia-Ling Tsai

Publications and Research

Purpose: To differentiate polypoidal choroidal vasculopathy (PCV) from choroidal neovascularization (CNV) and to determine the extent of PCV from fluorescein angiography (FA) using attention-based deep learning networks.

Methods: We build two deep learning networks for diagnosis of PCV using FA, one for detection and one for segmentation. Attention-gated convolutional neural network (AG-CNN) differentiates PCV from other types of wet age-related macular degeneration. Gradient-weighted class activation map (Grad-CAM) is generated to highlight important regions in the image for making the prediction, which offers explainability of the network. Attention-gated recurrent neural network (AG-PCVNet) for spatiotemporal prediction is applied for segmentation of PCV. …


Analysis Of Skills Sought By Employers Of Bachelors-Level Geoscientists, Gregory Shafer, Karen Viskupic, Anne E. Egger Feb 2022

Analysis Of Skills Sought By Employers Of Bachelors-Level Geoscientists, Gregory Shafer, Karen Viskupic, Anne E. Egger

Geosciences Faculty Publications and Presentations

Bachelors-level geoscientists make up the majority of the geoscience workforce, and positions for entry-level geoscientists are expected to grow rapidly over the next decade, with some jobs anticipating upward of 10% growth (National Center for O*NET Development, 2021). Are geoscience departments adequately preparing undergraduate students to succeed in these positions?


Lipschitz Regularity For The Parabolic P-Laplacian In The Heisenberg Group, Luca Capogna, Giovanna Citti, Xiao Zhong Feb 2022

Lipschitz Regularity For The Parabolic P-Laplacian In The Heisenberg Group, Luca Capogna, Giovanna Citti, Xiao Zhong

Mathematics Sciences: Faculty Publications

In this paper we establish the local Lipschitz regularity of weak solutions of a certain class of quasilinear, degenerate parabolic equations in the Heisenberg group Hn , or more in general in contact subRiemannian manifolds. In particular we extend to the non-stationary setting.


Chemistry Matters February 2022, Otterbein University Chemistry Department Feb 2022

Chemistry Matters February 2022, Otterbein University Chemistry Department

Chemistry Matters Department Newsletter

In this Issue:

Letter from the Chair, Faculty Scholarship, Chemistry in Action, Structural Methods in Chemistry, Summer Student Work, New Instrumentation Supports Student Learning, Post-COVID Adjustments in 2020 and Beyond, Otterbein University Students Benefit from Faculty Involvement in National Organizations, and Otterbein Student Chapter of ACS Nationally Recognized for the Second Year in a Row


The Data Analytics And The Science Revolution, Leila Halawi, Amal Clarke, Kelly George Feb 2022

The Data Analytics And The Science Revolution, Leila Halawi, Amal Clarke, Kelly George

Publications

This text highlights the difference between analytics and data science, using predictive analytic techniques to analyze different historical data, including aviation data and concrete data, interpreting the predictive models, and highlighting the steps to deploy the models and the steps ahead. The book combines the conceptual perspective and a hands-on approach to predictive analytics using SAS VIYA, an analytic and data management platform. The authors use SAS VIYA to focus on analytics to solve problems, highlight how analytics is applied in the airline and business environment, and compare several different modeling techniques. They decipher complex algorithms to demonstrate how they …


Air Pollution, Climate Change, And Our Health, Kathia Vargas Feliz Feb 2022

Air Pollution, Climate Change, And Our Health, Kathia Vargas Feliz

Dissertations, Theses, and Capstone Projects

Climate change is a subject that is creating a lot of controversies nowadays. From newspapers to researchers, there are big efforts going on trying to bring awareness about the effects of air pollution and climate change over time. It is recommended that governments all over the world, and people from all communities act by taking care of the environment because the situation might turn out to be irremediable. There is a quote by Leonardo Dicaprio stating, “Climate change is real. It is happening right now; it is the most urgent threat facing our entire species and we need to …


Understanding Deep Learning - Challenges And Prospects, Niha Adnan, Fahad Umer Feb 2022

Understanding Deep Learning - Challenges And Prospects, Niha Adnan, Fahad Umer

Department of Surgery

The developments in Artificial Intelligence have been on the rise since its advent. The advancements in this field have been the innovative research area across a wide range of industries, making its incorporation in dentistry inevitable. Artificial Intelligence techniques are making serious progress in the diagnostic and treatment planning aspects of dental clinical practice. This will ultimately help in the elimination of subjectivity and human error that are often part of radiographic interpretations, and will improve the overall efficiency of the process. The various types of Artificial Intelligence algorithms that exist today make the understanding of their application quite complex. …


Robot Learning From Human Observation Using Deep Neural Networks, Michael Elachkar Feb 2022

Robot Learning From Human Observation Using Deep Neural Networks, Michael Elachkar

Electronic Theses and Dissertations

Industrial robots have gained traction in the last twenty years and have become an integral component in any sector empowering automation. Specifically, the automotive industry implements a wide range of industrial robots in a multitude of assembly lines worldwide. These robots perform tasks with the utmost level of repeatability and incomparable speed. It is that speed and consistency that has always made the robotic task an upgrade over the same task completed by a human. The cost savings is a great return on investment causing corporations to automate and deploy robotic solutions wherever feasible.

The cost to commission and set …


Dynamic Interactions In Semiconducting Polymers; New Materials For Soft Electronics With Biomimetic Properties, Michael Udunyi Ocheje Feb 2022

Dynamic Interactions In Semiconducting Polymers; New Materials For Soft Electronics With Biomimetic Properties, Michael Udunyi Ocheje

Electronic Theses and Dissertations

The development of materials that can stretch while remaining conductive has generated significant research interest. The push for the development of these materials is due to their potential for cheaper, more durable electronics with the new functions (stretchability and healability) and form factors required for the next generation of wearable and skin-inspired electronics. Polymeric semiconductors have emerged as prime candidates for the development of these materials, due to their π-delocalized network which makes them conductive, their synthetic versatility, and their intrinsic mechanical properties. Furthermore, their ability to be solution processed provides an avenue for printing, roll-to-roll, and large area solution …


Provably Weak Instances Of Plwe Revisited, Again, Katherine Mendel Feb 2022

Provably Weak Instances Of Plwe Revisited, Again, Katherine Mendel

CSB and SJU Distinguished Thesis

Learning with Errors has emerged as a promising possibility for postquantum cryptography. Variants known as RLWE and PLWE have been shown to be more efficient, but the increased structure can leave them vulnerable to attacks for certain instantiations. This work aims to identify specific cases where proposed cryptographic schemes based on PLWE work particularly poorly under a specific attack.


Why Online Teaching Amplifies The Differences Between Instructors' Success, Olga Kosheleva, Vladik Kreinovich, Christian Servin Feb 2022

Why Online Teaching Amplifies The Differences Between Instructors' Success, Olga Kosheleva, Vladik Kreinovich, Christian Servin

Departmental Technical Reports (CS)

Empirical studies show that online teaching amplifies the differences between instructors: more successful instructors become even more successful, while the results of the instructors who were not very successful becomes even worse. There is a simple explanation for why the performance of not-perfect instructors decreases: in online teaching, there is less feedback, so these instructors get an indication that their teaching strategies do not work well even later than usual and thus, have fewer time to correct their teaching. However, the fact that the efficiency of good instructors rises is a mystery. In this paper, we provide a possible explanation …


How To React To Student Evaluations, Olga Kosheleva, Vladik Kreinovich, Christian Servin Feb 2022

How To React To Student Evaluations, Olga Kosheleva, Vladik Kreinovich, Christian Servin

Departmental Technical Reports (CS)

If most students comment that the course was too fast, a natural idea is to slow it down. If most students comment that the course was too slow, a natural idea is to speed it up. But what if half the students think the speed was too fast and half that the speed was too slow? A frequent reaction to such a situation is to conclude that the speed was just right and not change the speed the next time, but this may not be the right reaction: under the same speed, half of the students will struggle and may …


Toi-1842b: A Transiting Warm Saturn Undergoing Reinflation Around An Evolving Subgiant, R. A. Wittenmyer, J. T. Clark, T. Trifonov, B. C. Addison, D. J. Wright, K. G. Stassun, J. Horner, N. Lowson, J. Kielkopf, S. R. Kane, P. Plavchan, A. Shporer, H. Zhang, B. P. Bowler, M. W. Mengel, J. Okumura, M. Rabus, M. C. Johnson, D. Harbeck, R. Tronsgaard, L. A. Buchhave, K. A. Collins, K. I. Collins, T. Gan, Eric L.N. Jensen, S. B. Howell, E. Furlan, C. L. Gnilka, K. V. Lester, R. A. Matson, N. J. Scott, G. R. Ricker, R. Vanderspek, D. W. Latham, S. Seager, J. N. Winn, J. M. Jenkins, A. Rudat, E. V. Quintana, D. R. Rodriguez, D. A. Caldwell, S. N. Quinn, Z. Essack, L. G. Bouma Feb 2022

Toi-1842b: A Transiting Warm Saturn Undergoing Reinflation Around An Evolving Subgiant, R. A. Wittenmyer, J. T. Clark, T. Trifonov, B. C. Addison, D. J. Wright, K. G. Stassun, J. Horner, N. Lowson, J. Kielkopf, S. R. Kane, P. Plavchan, A. Shporer, H. Zhang, B. P. Bowler, M. W. Mengel, J. Okumura, M. Rabus, M. C. Johnson, D. Harbeck, R. Tronsgaard, L. A. Buchhave, K. A. Collins, K. I. Collins, T. Gan, Eric L.N. Jensen, S. B. Howell, E. Furlan, C. L. Gnilka, K. V. Lester, R. A. Matson, N. J. Scott, G. R. Ricker, R. Vanderspek, D. W. Latham, S. Seager, J. N. Winn, J. M. Jenkins, A. Rudat, E. V. Quintana, D. R. Rodriguez, D. A. Caldwell, S. N. Quinn, Z. Essack, L. G. Bouma

Physics & Astronomy Faculty Works

The imminent launch of space telescopes designed to probe the atmospheres of exoplanets has prompted new efforts to prioritize the thousands of transiting planet candidates for follow-up characterization. We report the detection and confirmation of TOI-1842b, a warm Saturn identified by TESS and confirmed with ground-based observations from Minerva-Australis, NRES, and the Las Cumbres Observatory Global Telescope. This planet has a radius of 1.04 (+0.06)/(-0.05) RJ, a mass of 0.214 (+0.040)/(-0.038) MJ, an orbital period of 9.5739 (+0.0002)/(-0.0001) days, and an extremely low density (ρ = 0.252 ± 0.091 g cm⁻³). TOI-1842b has among the …


Validation Of 13 Hot And Potentially Terrestrial Tess Planets, S. Giacalone, C. D. Dressing, C. Hedges, V. B. Kostov, K. A. Collins, Eric L.N. Jensen, D. A. Yahalomi, A. Bieryla, D. R. Ciardi, S. B. Howell, J. Lillo-Box, K. Barkaoui, J. G. Winters, E. Matthews, J. H. Livingston, S. N. Quinn, B. S. Safonov, C. Cadieux, E. Furlan, I. J. M. Crossfield, A. M. Mandell, E. A. Gilbert, E. Kruse, E. V. Quintana, G. R. Ricker, S. Seager, J. N. Winn, J. M. Jenkins, B. Duffy Adkins, D. Baker, T. Barclay, D. Barrado, N. M. Batalha, A. A. Belinski, Z. Benkhaldoun, L. A. Buchhave, L. Cacciapuoti, D. Charbonneau, A. Chontos, J. L. Christiansen, R. Cloutier, K. I. Collins, D. M. Conti, N. Cutting, S. Dixon, R. Doyon, M. El Mufti, E. Esparza-Borges, Z. Essack, A. Fukui, T. Gan, K. Gary, M. Ghachoui, M. Gillon, E. Girardin, A. Glidden, E. J. Gonzales, P. Guerra, E. P. Horch, K. G. Hełminiak, A. W. Howard, D. Huber, J. M. Irwin, G. Isopi, E. Jehin, T. Kagetani, S. R. Kane, K. Kawauchi, J. F. Kielkopf, P. Lewin, L. Luker, M. B. Lund, F. Mallia, S. Mao, B. Massey, R. A. Matson, I. Mireles, M. Mori, F. Murgas, N. Narita, T. O'Dwyer, E. A. Petigura, A. S. Polanski, F. J. Pozuelos, E. Palle, H. Parviainen, P. P. Plavchan, H. M. Relles, P. Robertson, M. E. Rose, P. Rowden, A. Roy, A. B. Savel, J. E. Schlieder, C. Schnaible, R. P. Schwarz, R. Sefako, A. Selezneva, B. Skinner, C. Stockdale, I. A. Strakhov, T.-G. Tan, G. Torres, R. Tronsgaard, J. D. Twicken, D. Vermilion, I. A. Waite, B. Walter, G. Wang, C. Ziegler, Y. Zou Feb 2022

Validation Of 13 Hot And Potentially Terrestrial Tess Planets, S. Giacalone, C. D. Dressing, C. Hedges, V. B. Kostov, K. A. Collins, Eric L.N. Jensen, D. A. Yahalomi, A. Bieryla, D. R. Ciardi, S. B. Howell, J. Lillo-Box, K. Barkaoui, J. G. Winters, E. Matthews, J. H. Livingston, S. N. Quinn, B. S. Safonov, C. Cadieux, E. Furlan, I. J. M. Crossfield, A. M. Mandell, E. A. Gilbert, E. Kruse, E. V. Quintana, G. R. Ricker, S. Seager, J. N. Winn, J. M. Jenkins, B. Duffy Adkins, D. Baker, T. Barclay, D. Barrado, N. M. Batalha, A. A. Belinski, Z. Benkhaldoun, L. A. Buchhave, L. Cacciapuoti, D. Charbonneau, A. Chontos, J. L. Christiansen, R. Cloutier, K. I. Collins, D. M. Conti, N. Cutting, S. Dixon, R. Doyon, M. El Mufti, E. Esparza-Borges, Z. Essack, A. Fukui, T. Gan, K. Gary, M. Ghachoui, M. Gillon, E. Girardin, A. Glidden, E. J. Gonzales, P. Guerra, E. P. Horch, K. G. Hełminiak, A. W. Howard, D. Huber, J. M. Irwin, G. Isopi, E. Jehin, T. Kagetani, S. R. Kane, K. Kawauchi, J. F. Kielkopf, P. Lewin, L. Luker, M. B. Lund, F. Mallia, S. Mao, B. Massey, R. A. Matson, I. Mireles, M. Mori, F. Murgas, N. Narita, T. O'Dwyer, E. A. Petigura, A. S. Polanski, F. J. Pozuelos, E. Palle, H. Parviainen, P. P. Plavchan, H. M. Relles, P. Robertson, M. E. Rose, P. Rowden, A. Roy, A. B. Savel, J. E. Schlieder, C. Schnaible, R. P. Schwarz, R. Sefako, A. Selezneva, B. Skinner, C. Stockdale, I. A. Strakhov, T.-G. Tan, G. Torres, R. Tronsgaard, J. D. Twicken, D. Vermilion, I. A. Waite, B. Walter, G. Wang, C. Ziegler, Y. Zou

Physics & Astronomy Faculty Works

The James Webb Space Telescope will be able to probe the atmospheres and surface properties of hot, terrestrial planets via emission spectroscopy. We identify 18 potentially terrestrial planet candidates detected by the Transiting Exoplanet Survey Satellite (TESS) that would make ideal targets for these observations. These planet candidates cover a broad range of planet radii (Rp ∼ 0.6–2.0R) and orbit stars of various magnitudes (Ks = 5.78–10.78, V = 8.4–15.69) and effective temperatures (Teff ∼ 3000–6000 K). We use ground-based observations collected through the TESS Follow-up Observing Program (TFOP) and two …


Speeding Up Routing Schedules On Aisle Graphs With Single Access, Francesco Betti Sorbelli, Stefano Carpin, Federico Coro, Sajal K. Das, Alfredo Navarra, Cristina M. Pinotti Feb 2022

Speeding Up Routing Schedules On Aisle Graphs With Single Access, Francesco Betti Sorbelli, Stefano Carpin, Federico Coro, Sajal K. Das, Alfredo Navarra, Cristina M. Pinotti

Computer Science Faculty Research & Creative Works

In this article, we study the orienteering aisle-graph single-access problem (OASP), a variant of the orienteering problem for a robot moving in a so-called single-access aisle graph, i.e., a graph consisting of a set of rows that can be accessed from one side only. Aisle graphs model, among others, vineyards or warehouses. Each aisle-graph vertex is associated with a reward that a robot obtains when it visits the vertex itself. As the energy of the robot is limited, only a subset of vertices can be visited with a fully charged battery. The objective is to maximize the total reward collected …


Comprehensive Evaluation Of A High-Temperature Resistant Re-Crosslinkable Preformed Particle Gel For Water Management, Bowen Yu, Shuda Zhao, Yifu Long, Baojun Bai, Thomas P. Schuman Feb 2022

Comprehensive Evaluation Of A High-Temperature Resistant Re-Crosslinkable Preformed Particle Gel For Water Management, Bowen Yu, Shuda Zhao, Yifu Long, Baojun Bai, Thomas P. Schuman

Geosciences and Geological and Petroleum Engineering Faculty Research & Creative Works

Gel treatment has been widely applied to control conformance for improving oil recovery and control water production in mature oil fields. However, most of the hydrogel systems are limited when being applied in the harsh environments of high temperatures. A systematic evaluation was conducted in this study to evaluate a modified PPG product, the high temperature resistant re-crosslinkable preformed particle gel (HT-RPPG) which can re-crosslink to form a bulky material and keep thermostable in the large-opening features after placement. This material was developed to overcome the limitations of conventional PPGs in the reservoirs with large- opening features such as open …


A Multigrid Multilevel Monte Carlo Method For Stokes–Darcy Model With Random Hydraulic Conductivity And Beavers–Joseph Condition, Zhipeng Yang, Ju Ming, Changxin Qiu, Maojun Li, Xiaoming He Feb 2022

A Multigrid Multilevel Monte Carlo Method For Stokes–Darcy Model With Random Hydraulic Conductivity And Beavers–Joseph Condition, Zhipeng Yang, Ju Ming, Changxin Qiu, Maojun Li, Xiaoming He

Mathematics and Statistics Faculty Research & Creative Works

A multigrid multilevel Monte Carlo (MGMLMC) method is developed for the stochastic Stokes–Darcy interface model with random hydraulic conductivity both in the porous media domain and on the interface. Three interface conditions with randomness are considered on the interface between Stokes and Darcy equations, especially the Beavers–Joesph interface condition with random hydraulic conductivity. Because the randomness through the interface affects the flow in the Stokes domain, we investigate the coupled stochastic Stokes–Darcy model to improve the fidelity. Under suitable assumptions on the random coefficient, we prove the existence and uniqueness of the weak solution of the variational form. To construct …


Metallic Networks And Hydrogen Compensation In Highly Nonstoichiometric Amorphous In₂O₃₋ₓ, Julia E. Medvedeva, E. Caputa-Hatley, I. Zhuravlev Feb 2022

Metallic Networks And Hydrogen Compensation In Highly Nonstoichiometric Amorphous In₂O₃₋ₓ, Julia E. Medvedeva, E. Caputa-Hatley, I. Zhuravlev

Physics Faculty Research & Creative Works

The unique response of amorphous ionic oxides to changes in oxygen stoichiometry is investigated using computationally intensive ab initio molecular dynamics simulations, comprehensive structural analysis, and hybrid density-functional calculations for the oxygen defect formation energy and electronic properties of amorphous In2O3-x with x = 0-0.185. In marked contrast to nonstoichiometric crystalline nanocomposites with clusters of metallic inclusions inside an insulating matrix, the lack of oxygen in amorphous indium oxide is distributed between a large fraction of undercoordinated In atoms, leading to an extended shallow state for x < 0.037, a variety of weakly and strongly localized states for 0.074 < x < 0.148, and a percolation-like network of single-atom chains of metallic In-In bonds for x > 0.185. The calculated carrier concentration increases from 3.3 x 10 …


A New Geometric Structure On Tangent Bundles, Nikos Georgiou, Brendan Guilfoyle Feb 2022

A New Geometric Structure On Tangent Bundles, Nikos Georgiou, Brendan Guilfoyle

Publications

For a Riemannian manifold (N, g), we construct a scalar flat neutral metric G on the tangent bundle TN. The metric is locally conformally flat if and only if either N is a 2- dimensional manifold or (N, g) is a real space form. It is also shown that G is locally symmetric if and only if g is locally symmetric. We then study submanifolds in TN and, in particular, find the conditions for a curve to be geodesic. The conditions for a Lagrangian graph in the tangent bundle TN to have parallel mean curvature …


To Buy Green Or Not To Buy Green: Do Structural Dependencies Block Ecological Responsiveness?, Simon J.D. Schillebeeckx, Teemu Kautonen, Henri Hakata Feb 2022

To Buy Green Or Not To Buy Green: Do Structural Dependencies Block Ecological Responsiveness?, Simon J.D. Schillebeeckx, Teemu Kautonen, Henri Hakata

Research Collection Lee Kong Chian School Of Business

Despite the significant increase in interest in sustainable business practices, decisions on switching to more environmentally friendly input materials are understudied. In a conjoint experiment, we presented 267 Finnish manufacturing firms with an opportunity to acquire an alternative, more ecological input material and investigated their willingness to switch to that material. We find that in general, firms are willing to substitute their current principal input with a more ecological alternative under conditions of functional parity. However, such willingness is contingent on the firm’s value creation structures. Specifically, if the products and processes driving the firm’s value creation rely more on …


Reproducing Kernel Method For Solving Fuzzy Initial Value Problems, Qamar Kamel Dallashi Feb 2022

Reproducing Kernel Method For Solving Fuzzy Initial Value Problems, Qamar Kamel Dallashi

Theses

In this thesis, numerical solution of the fuzzy initial value problem will be investigated based on the reproducing kernel method. Problems of this type are either difficult to solve or impossible, in some cases, since they will produce a complicated optimized problem. To overcome this challenge, reproducing kernel method will be modified to solve this type of problems. Theoretical and numerical results will be presented to show the efficiency of the proposed method.


Time-Efficient Algorithm For The Order-Statistic Operations In Lattice Data Structure, Joseph Mendis Feb 2022

Time-Efficient Algorithm For The Order-Statistic Operations In Lattice Data Structure, Joseph Mendis

Undergraduate University Honors Capstones

Data structures are an essential part of almost all software programs. The primary operations of most data structures are searching, insertion, deletion, and finding the Kth smallest element. To be of practical use, operations on data structures should be fast and should not use much memory space; in other words, the time and space complexities should not be enormous. This research project provides an algorithm, called FindKth, for the order-statistic operations of finding the ATth smallest element in Lattice Data Structures. In the average case, our algorithm is of time complexity O(n3/2), and it is of time complexity O(n) for …


A Natural Causality-Motivated Description Of Learning, Olga Kosheleva, Vladik Kreinovich Feb 2022

A Natural Causality-Motivated Description Of Learning, Olga Kosheleva, Vladik Kreinovich

Departmental Technical Reports (CS)

Teaching is not easy. One of the main reasons why it is not easy is that the existing descriptions of the teaching process are not very precise -- and thus, we cannot use the usual optimization techniques, techniques which require a precise model of the corresponding phenomenon. It is therefore desirable to come up with a precise description of the learning process. To come up with such a description, we notice that on the set of all possible states of learning, there is a natural order s ≤ s' meaning that we can bring the student from the state s …


Data Processing Under Fuzzy Uncertainty: Towards More Efficient Algorithm, Hung T. Nguyen, Olga Kosheleva, Vladik Kreinovich Feb 2022

Data Processing Under Fuzzy Uncertainty: Towards More Efficient Algorithm, Hung T. Nguyen, Olga Kosheleva, Vladik Kreinovich

Departmental Technical Reports (CS)

In many practical situations, we need to process data under fuzzy uncertainty: we have fuzzy information about the algorithm's input, and we want to find the resulting information about the algorithm's output. It is known that this problem can be reduced to computing the range of the algorithm over alpha-cuts of the input. Since the fuzzy degrees are usually known with accuracy at best 0.1, it is sufficient to repeat this range-computing procedure for 11 values alpha = 0, 0.1, ..., 1.0. However, a straightforward application of this idea requires 11 times longer computation time than each range estimation -- …


Why Gaussian Copulas Are Ubiquitous In Economics: Fuzzy-Related Explanation, Chon Van Le, Olga Kosheleva, Vladik Kreinovich Feb 2022

Why Gaussian Copulas Are Ubiquitous In Economics: Fuzzy-Related Explanation, Chon Van Le, Olga Kosheleva, Vladik Kreinovich

Departmental Technical Reports (CS)

In many real-life situations, deviations are caused by a large number of independent factors. It is known that in such situations, the distribution of the resulting deviations is close to Gaussian, and thus, that the copulas -- that describe the multi-D distributions as a function of 1-D (marginal) ones -- are also Gaussian. In the past, these conclusions were also applied to economic phenomena, until the 2008 crisis showed that in economics, Gaussian models can lead to disastrous consequences. At present, all economists agree that the economic distributions are not Gaussian -- however, surprisingly, Gaussian copulas still often provide an …