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Faculty Publications

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Full-Text Articles in Physical Sciences and Mathematics

Experimental Determination Of The (0/−) Level For Mg Acceptors In Β-Ga2O3 Crystals, Christopher A. Lenyk, Trevor A . Gustafson, Sergey A. Basun, Larry E. Halliburton, Nancy C. Giles Apr 2020

Experimental Determination Of The (0/−) Level For Mg Acceptors In Β-Ga2O3 Crystals, Christopher A. Lenyk, Trevor A . Gustafson, Sergey A. Basun, Larry E. Halliburton, Nancy C. Giles

Faculty Publications

Electron paramagnetic resonance (EPR) is used to experimentally determine the (0/−) level of the Mg acceptor in an Mg-doped β-Ga2O3 crystal. Our results place this level 0.65 eV (±0.05 eV) above the valence band, a position closer to the valence band than the predictions of several recent computational studies. The crystal used in this investigation was grown by the Czochralski method and contains large concentrations of Mg acceptors and Ir donors, as well as a small concentration of Fe ions and an even smaller concentration of Cr ions. Below room temperature, illumination with 325 nm laser light …

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Seasonal Patterns Of Surface Inorgamic Carbon System Variables In The Gulf Of Mexico Inferred From A Regional High-Resolution Ocean Biogeochemical Model, Fabian A. Gomez, Rik Wanninkhof, Leticia Barbero, Sang Ki Lee, Frank J. Hernandez Mar 2020

Seasonal Patterns Of Surface Inorgamic Carbon System Variables In The Gulf Of Mexico Inferred From A Regional High-Resolution Ocean Biogeochemical Model, Fabian A. Gomez, Rik Wanninkhof, Leticia Barbero, Sang Ki Lee, Frank J. Hernandez

Faculty Publications

Uncertainties in carbon chemistry variability still remain large in the Gulf of Mexico (GoM), as data gaps limit our ability to infer basin-wide patterns. Here we configure and validate a regional high-resolution ocean biogeochemical model for the GoM to describe seasonal patterns in surface pressure of CO2 (pCO2), aragonite saturation state (ΩAr), and sea–air CO2 flux. Model results indicate that seasonal changes in surface pCO2 are strongly controlled by temperature across most of the GoM basin, except in the vicinity of the Mississippi–Atchafalaya river system delta, where runoff largely controls dissolved inorganic carbon (DIC) …

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Understanding Fluid Dynamics From Langevin And Fokker–Planck Equations, Andrei Medved, Riley Davis, Paula A. Vasquez Mar 2020

Understanding Fluid Dynamics From Langevin And Fokker–Planck Equations, Andrei Medved, Riley Davis, Paula A. Vasquez

Faculty Publications

The Langevin equations (LE) and the Fokker–Planck (FP) equations are widely used to describe fluid behavior based on coarse-grained approximations of microstructure evolution. In this manuscript, we describe the relation between LE and FP as related to particle motion within a fluid. The manuscript introduces undergraduate students to two LEs, their corresponding FP equations, and their solutions and physical interpretation.

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Long-Term Evidence Shows That Crop-Rotation Diversification Increases Agricultural Resilience To Adverse Growing Conditions In North America, Timothy M. Bowles, Maria Mooshammer, Yvonne Socolar, Francisco Calderon, Michel A. Cavigelli, Steve W. Culman, William Deen, Craig F. Drury, Axel Garcia Y Garcia, Amelie C. M. Gaudin, W. Scott Harkcom, R. Michael Lehman, Shannon L. Osborne, G. Philip Robertson, Jonathan Salerno, Marty R. Schmer, Jeffrey Strock, A. Stuart Grandy Mar 2020

Long-Term Evidence Shows That Crop-Rotation Diversification Increases Agricultural Resilience To Adverse Growing Conditions In North America, Timothy M. Bowles, Maria Mooshammer, Yvonne Socolar, Francisco Calderon, Michel A. Cavigelli, Steve W. Culman, William Deen, Craig F. Drury, Axel Garcia Y Garcia, Amelie C. M. Gaudin, W. Scott Harkcom, R. Michael Lehman, Shannon L. Osborne, G. Philip Robertson, Jonathan Salerno, Marty R. Schmer, Jeffrey Strock, A. Stuart Grandy

Faculty Publications

A grand challenge facing humanity is how to produce food for a growing population in the face of a changing climate and environmental degradation. Although empirical evidence remains sparse, management strategies that increase environmental sustainability, such as increasing agroecosystem diversity through crop rotations, may also increase resilience to weather extremes without sacrificing yields. We used multilevel regression analyses of long-term crop yield datasets across a continental precipitation gradient to assess how temporal crop diversification affects maize yields in intensively managed grain systems. More diverse rotations increased maize yields over time and across all growing conditions (28.1% on average), including in …

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Gw190425: Observation Of A Compact Binary Coalescence With Total Mass ∼ 3.4 M O, B. P. Abbott, R. Abbott, T. D. Abbott, S. Abraham, F. Acernese, K. Ackley, C. Adams, R. X. Adhikari, V. B. Adya, C. Affeldt, M. Agathos, K. Agatsuma, N. Aggarwal, O. D. Aguiar, L. Aiello, A. Ain, P. Ajith, G. Allen, A. Allocca, M. A. Aloy, P. A. Altin, A. Amato, S. Anand, A. Ananyeva, S. B. Anderson, W. G. Anderson, S. V. Angelova, S. Antier, S. Appert, K. Arai, M. C. Araya, Tiffany Z. Summerscales Mar 2020

Gw190425: Observation Of A Compact Binary Coalescence With Total Mass ∼ 3.4 M O, B. P. Abbott, R. Abbott, T. D. Abbott, S. Abraham, F. Acernese, K. Ackley, C. Adams, R. X. Adhikari, V. B. Adya, C. Affeldt, M. Agathos, K. Agatsuma, N. Aggarwal, O. D. Aguiar, L. Aiello, A. Ain, P. Ajith, G. Allen, A. Allocca, M. A. Aloy, P. A. Altin, A. Amato, S. Anand, A. Ananyeva, S. B. Anderson, W. G. Anderson, S. V. Angelova, S. Antier, S. Appert, K. Arai, M. C. Araya, Tiffany Z. Summerscales

Faculty Publications

© 2020. The Author(s). Published by the American Astronomical Society.. On 2019 April 25, the LIGO Livingston detector observed a compact binary coalescence with signal-to-noise ratio 12.9. The Virgo detector was also taking data that did not contribute to detection due to a low signal-to-noise ratio, but were used for subsequent parameter estimation. The 90% credible intervals for the component masses range from to if we restrict the dimensionless component spin magnitudes to be smaller than 0.05). These mass parameters are consistent with the individual binary components being neutron stars. However, both the source-frame chirp mass and the total mass …

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The Analytics Managers Ultimate Guide For Working With Universities, Robert J. Mcgrath Mar 2020

The Analytics Managers Ultimate Guide For Working With Universities, Robert J. Mcgrath

Faculty Publications

The challenges organizations are having related to finding (and retaining) deep analytical talent did not materialize out of thin air…or overnight. Analytics and Data science – and the role of the analytics professional – has evolved over the last several decades and has been fueled by our ability to capture and process increasingly larger and more complex variations of data and our desire to gain increasingly granular insights to fuel innovation and creativity. While many organizations recognize that a partnership with a university can be a resource to many of these challenges, the best way to start a conversation with …

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A New Ectotherm 3d Tracking And Behavior Analytics System Using A Depth-Based Approach With Color Validation, With Preliminary Data On Kihansi Spray Toad (Nectophrynoides Asperginis) Activity, Philip Bal, Damian Lyons, Avishai Shuter Mar 2020

A New Ectotherm 3d Tracking And Behavior Analytics System Using A Depth-Based Approach With Color Validation, With Preliminary Data On Kihansi Spray Toad (Nectophrynoides Asperginis) Activity, Philip Bal, Damian Lyons, Avishai Shuter

Faculty Publications

The Kihansi spray toad (Nectophrynoides asperginis), classified as Extinct in the Wild by the IUCN, is being bred at the Wildlife Conservation Society’s (WCS) Bronx Zoo as part of an effort to successfully reintroduce the species into the wild. Thousands of toads live at the Bronx Zoo presenting an opportunity to learn more about their behaviors for the first time, at scale. It is impractical to perform manual observations for long periods of time. This paper reports on the development of a RGB-D tracking and analytics approach that allows researchers to accurately and efficiently gather information about the toads’ behavior. …

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Hydrogen Peroxide Triggers An Increase In Cell Surface Expression Of System XC− In Cultured Human Glioma Cells, Leah A. Chase, Mary Verheulen Kleyn, Natasha Schiller, Abby Goltz King, Guillermo Flores, Sasha Balcazar Engelsman, Christina Bowles, Sara Lang Smith, Anne E. Robinson, Jeffrey Rothstein Mar 2020

Hydrogen Peroxide Triggers An Increase In Cell Surface Expression Of System XC− In Cultured Human Glioma Cells, Leah A. Chase, Mary Verheulen Kleyn, Natasha Schiller, Abby Goltz King, Guillermo Flores, Sasha Balcazar Engelsman, Christina Bowles, Sara Lang Smith, Anne E. Robinson, Jeffrey Rothstein

Faculty Publications

System xc− exchanges extracellular cystine for intracellular glutamate across the plasma membrane of many cell types. One of the physiological roles of System xc− is to provide cystine for synthesis of the antioxidant glutathione. Here we report that hydrogen peroxide (H2O2) triggers the translocation of System xc− to the plasma membrane within 10 min of the initial exposure. Specifically, we observed a three-fold increase in 35S-L-cystine uptake following a 10 min exposure to 0.3 mM H2O2. This effect was dose-dependent with an EC50 for …

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Near-Infrared-Sensitive Photorefractive Sn2P2S6 Crystals Grown By The Bridgman Method, O. M. Shumelyuk, A. Y. Volkov, Y. Skrypka, Larry E. Halliburton, Nancy C. Giles, Christopher A. Lenyk, Sergey A. Basun, A. A. Grabar, Y. M. Vysochansky, S. G. Odoulov, D. R. Evans Mar 2020

Near-Infrared-Sensitive Photorefractive Sn2P2S6 Crystals Grown By The Bridgman Method, O. M. Shumelyuk, A. Y. Volkov, Y. Skrypka, Larry E. Halliburton, Nancy C. Giles, Christopher A. Lenyk, Sergey A. Basun, A. A. Grabar, Y. M. Vysochansky, S. G. Odoulov, D. R. Evans

Faculty Publications

Ferroelectric tin hypothiodiphosphate (Sn2P2S6) crystals are well-known for their significant piezoelectric, electro-optic, and nonlinear optical properties. These crystals have usually been grown by a vapor transport technique. We report in this paper on the first study of photorefractive nonlinearity in Sn2P2S6 crystals grown by the Bridgman method. Pronounced photorefraction is observed in the near-infrared region of the spectrum even with no preliminary optical sensitizing.

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Non-Linear Statistical Photocalibration Of Photodetectors Without Calibrated Light Sources, Stephen C. Cain Mar 2020

Non-Linear Statistical Photocalibration Of Photodetectors Without Calibrated Light Sources, Stephen C. Cain

Faculty Publications

Calibration of CCD arrays is commonly conducted using dark frames. Non-absolute calibration techniques only measure the relative response of the detectors. For absolute calibration to be achieved, a second calibration is sometimes utilized by looking at sources with known radiances. A process like this can be used to calibrate photodetectors if a calibration source is available and sensor time can be spared to perform the operation. A previous attempt at creating a procedure for calibrating a photodetector using the underlying Poisson nature of the photodetection statistics relied on a linear model. This effort produced the statistically applied non-uniformity calibration algorithm, …

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Synthesizing General Electromagnetic Partially Coherent Sources From Random, Correlated Complex Screens, Milo W. Hyde Iv Mar 2020

Synthesizing General Electromagnetic Partially Coherent Sources From Random, Correlated Complex Screens, Milo W. Hyde Iv

Faculty Publications

We present a method to generate any genuine electromagnetic partially coherent source (PCS) from correlated, stochastic complex screens. The method described here can be directly implemented on existing spatial-light-modulator-based vector beam generators and can be used in any application which utilizes electromagnetic PCSs. Our method is based on the genuine cross-spectral density matrix criterion. Applying that criterion, we show that stochastic vector field realizations (corresponding to a desired electromagnetic PCS) can be generated by passing correlated Gaussian random numbers through “filters” with space-variant transfer functions. We include step-by-step instructions on how to generate the electromagnetic PCS field realizations. As an …

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Optimizing The Environmental And Economic Sustainability Of Remote Community Infrastructure, Jamie E. Filer, Justin D. Delorit, Andrew J. Hoisington, Steven J. Schuldt Mar 2020

Optimizing The Environmental And Economic Sustainability Of Remote Community Infrastructure, Jamie E. Filer, Justin D. Delorit, Andrew J. Hoisington, Steven J. Schuldt

Faculty Publications

Remote communities such as rural villages, post-disaster housing camps, and military forward operating bases are often located in remote and hostile areas with limited or no access to established infrastructure grids. Operating these communities with conventional assets requires constant resupply, which yields a significant logistical burden, creates negative environmental impacts, and increases costs. For example, a 2000-member isolated village in northern Canada relying on diesel generators required 8.6 million USD of fuel per year and emitted 8500 tons of carbon dioxide. Remote community planners can mitigate these negative impacts by selecting sustainable technologies that minimize resource consumption and emissions. However, …

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Cyber-Physical Security With Rf Fingerprint Classification Through Distance Measure Extensions Of Generalized Relevance Learning Vector Quantization, Trevor J. Bihl, Todd J. Paciencia, Kenneth W. Bauer Jr., Michael A. Temple Feb 2020

Cyber-Physical Security With Rf Fingerprint Classification Through Distance Measure Extensions Of Generalized Relevance Learning Vector Quantization, Trevor J. Bihl, Todd J. Paciencia, Kenneth W. Bauer Jr., Michael A. Temple

Faculty Publications

Radio frequency (RF) fingerprinting extracts fingerprint features from RF signals to protect against masquerade attacks by enabling reliable authentication of communication devices at the “serial number” level. Facilitating the reliable authentication of communication devices are machine learning (ML) algorithms which find meaningful statistical differences between measured data. The Generalized Relevance Learning Vector Quantization-Improved (GRLVQI) classifier is one ML algorithm which has shown efficacy for RF fingerprinting device discrimination. GRLVQI extends the Learning Vector Quantization (LVQ) family of “winner take all” classifiers that develop prototype vectors (PVs) which represent data. In LVQ algorithms, distances are computed between exemplars and PVs, and …

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Search For Rare Or Forbidden Decays Of The D0 Meson, J. P. Lees, V. Poireau, V. Tisserand, E. Grauges, A. Palano, G. Eigen, D. N. Brown, Yu. G. Kolomensky, M. Fritsch, H. Koch, T. Schroeder, R. Cheaib, C. Hearty, T. S. Mattison, J. A. Mckenna, R. Y. So, V. E. Blinov, A. R. Buzykaev, V. P. Druzhinin, Milind Purohit Feb 2020

Search For Rare Or Forbidden Decays Of The D0 Meson, J. P. Lees, V. Poireau, V. Tisserand, E. Grauges, A. Palano, G. Eigen, D. N. Brown, Yu. G. Kolomensky, M. Fritsch, H. Koch, T. Schroeder, R. Cheaib, C. Hearty, T. S. Mattison, J. A. Mckenna, R. Y. So, V. E. Blinov, A. R. Buzykaev, V. P. Druzhinin, Milind Purohit

Faculty Publications

We present a search for nine lepton-number-violating and three lepton-flavor-violating neutral charm decays of the type D0 → h'−h−ℓ'+ℓ+ and D0→h'−h+ℓ'±ℓ∓, where h and h0 represent a K or π meson and ℓ and ℓ′ an electron or muon. The analysis is based on 468 fb−1 of e+e− annihilation data collected at or close to the ϒ(4S) resonance with the BABAR detector at the SLAC National Accelerator Laboratory. No significant signal is observed for any of the twelve modes, …

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Geology Of Nacogdoches, Texas: Texas Academy Of Science March 1, 2020, R. Larell Nielson, Mike Read, Mindy Faulkner, Hannah C. Chambers, Jessica O'Neal Feb 2020

Geology Of Nacogdoches, Texas: Texas Academy Of Science March 1, 2020, R. Larell Nielson, Mike Read, Mindy Faulkner, Hannah C. Chambers, Jessica O'Neal

Faculty Publications

No abstract provided.

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Wireless Underground Communications In Sewer And Stormwater Overflow Monitoring: Radio Waves Through Soil And Asphalt Medium, Usman Raza, Abdul Salam Feb 2020

Wireless Underground Communications In Sewer And Stormwater Overflow Monitoring: Radio Waves Through Soil And Asphalt Medium, Usman Raza, Abdul Salam

Faculty Publications

Storm drains and sanitary sewers are prone to backups and overflows due to extra amount wastewater entering the pipes. To prevent that, it is imperative to efficiently monitor the urban underground infrastructure. The combination of sensors system and wireless underground communication system can be used to realize urban underground IoT applications, e.g., storm water and wastewater overflow monitoring systems. The aim of this article is to establish a feasibility of the use of wireless underground communications techniques, and wave propagation through the subsurface soil and asphalt layers, in an underground pavement system for storm water and sewer overflow monitoring application. …

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Critical Temperature Prediction Of Superconductors Based On Atomic Vectors And Deep Learning, Shaobo Li, Yabo Dan, Xiang Li, Tiantian Hu, Rongzhi Dong, Zhuo Cao, Jianjun Hu Feb 2020

Critical Temperature Prediction Of Superconductors Based On Atomic Vectors And Deep Learning, Shaobo Li, Yabo Dan, Xiang Li, Tiantian Hu, Rongzhi Dong, Zhuo Cao, Jianjun Hu

Faculty Publications

In this paper, a hybrid neural network (HNN) that combines a convolutional neural network (CNN) and long short-term memory neural network (LSTM) is proposed to extract the high-level characteristics of materials for critical temperature (Tc) prediction of superconductors. Firstly, by obtaining 73,452 inorganic compounds from the Materials Project (MP) database and building an atomic environment matrix, we obtained a vector representation (atomic vector) of 87 atoms by singular value decomposition (SVD) of the atomic environment matrix. Then, the obtained atom vector was used to implement the coded representation of the superconductors in the order of the atoms in the chemical …

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A Guide To Ligo-Virgo Detector Noise And Extraction Of Transient Gravitational-Wave Signals, B. P. Abbott, R. Abbott, T. D. Abbott, S. Abraham, F. Acernese, K. Ackley, C. Adams, V. B. Adya, C. Affeldt, M. Agathos, K. Agatsuma, N. Aggarwal, O. D. Aguiar, L. Aiello, A. Ain, P. Ajith, T. Alford, G. Allen, A. Allocca, M. A. Aloy, P. A. Altin, A. Amato, A. Ananyeva, S. B. Anderson, W. G. Anderson, S. V. Angelova, S. Antier, S. Appert, K. Arai, M. C. Araya, J. S. Areeda, Tiffany Summerscales Feb 2020

A Guide To Ligo-Virgo Detector Noise And Extraction Of Transient Gravitational-Wave Signals, B. P. Abbott, R. Abbott, T. D. Abbott, S. Abraham, F. Acernese, K. Ackley, C. Adams, V. B. Adya, C. Affeldt, M. Agathos, K. Agatsuma, N. Aggarwal, O. D. Aguiar, L. Aiello, A. Ain, P. Ajith, T. Alford, G. Allen, A. Allocca, M. A. Aloy, P. A. Altin, A. Amato, A. Ananyeva, S. B. Anderson, W. G. Anderson, S. V. Angelova, S. Antier, S. Appert, K. Arai, M. C. Araya, J. S. Areeda, Tiffany Summerscales

Faculty Publications

© 2020 IOP Publishing Ltd. The LIGO Scientific Collaboration and the Virgo Collaboration have cataloged eleven confidently detected gravitational-wave events during the first two observing runs of the advanced detector era. All eleven events were consistent with being from well-modeled mergers between compact stellar-mass objects: black holes or neutron stars. The data around the time of each of these events have been made publicly available through the gravitational-wave open science center. The entirety of the gravitational-wave strain data from the first and second observing runs have also now been made publicly available. There is considerable interest among the broad scientific …

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Expectation Values Of Coherent States For Su(2) Lattice Gauge Theories, Klaus Liegener, Ernst-Albrecht Zwicknagel Feb 2020

Expectation Values Of Coherent States For Su(2) Lattice Gauge Theories, Klaus Liegener, Ernst-Albrecht Zwicknagel

Faculty Publications

This article investigates properties of semiclassical Gauge Field Theory Coherent States for general quantum gauge theories. Useful, e.g., for the canonical formulation of Lattice Gauge Theories these states are labelled by a point in the classical phase space and constructed such that the expectation values of the canonical operators are sharply peaked on said phase space point. For the case of the non-abelian gauge group SU(2), we will explicitly compute the expectation value of general polynomials including the first order quantum corrections. This allows asking more precise questions about the quantum fluctuations of any given semiclassical system.

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The Role Of Climate Change Education On Individual Lifetime Carbon Emissions, Eugene Cordero, Diana Centeno Delgado, Anne Marie Todd Feb 2020

The Role Of Climate Change Education On Individual Lifetime Carbon Emissions, Eugene Cordero, Diana Centeno Delgado, Anne Marie Todd

Faculty Publications

Strategies to mitigate climate change often center on clean technologies, such as electric vehicles and solar panels, while the mitigation potential of a quality educational experience is rarely discussed. In this paper, we investigate the long-term impact that an intensive one year university course had on individual carbon emissions by surveying students at least five years after having taken the course. A majority of course graduates reported pro-environmental decisions (i.e., type of car to buy, food choices) that they attributed at least in part to experiences gained in the course. Furthermore, our carbon footprint analysis suggests that for the average …

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Effects Of Optical Turbulence And Density Gradients On Particle Image Velocimetry, Silvia Matt, Gero Nootz, Samuel Hellman, Weilin Hou Feb 2020

Effects Of Optical Turbulence And Density Gradients On Particle Image Velocimetry, Silvia Matt, Gero Nootz, Samuel Hellman, Weilin Hou

Faculty Publications

Particle image velocimetry (PIV) is a well-established tool to collect high-resolution velocity and turbulence data in the laboratory, in both air and water. Laboratory experiments are often performed under conditions of constant temperature or salinity or in flows with only small gradients of these properties. At larger temperature or salinity variations, the changes in the index of refraction of water or air due to turbulent microstructure can lead to so-called optical turbulence. We observed a marked influence of optical turbulence on particle imaging in PIV. The effect of index of refraction variations on PIV has been described in air for …

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A Monte Carlo Approach To Closing The Reality Gap, Damian Lyons, James Finocchiaro, Michael Novitzky, Christopher Korpela Feb 2020

A Monte Carlo Approach To Closing The Reality Gap, Damian Lyons, James Finocchiaro, Michael Novitzky, Christopher Korpela

Faculty Publications

We propose a novel approach to the ’reality gap’ problem, i.e., modifying a robot simulation so that its performance becomes more similar to observed real world phenomena. This problem arises whether the simulation is being used by human designers or in an automated policy development mechanism. We expect that the program/policy is developed using simulation, and subsequently deployed on a real system. We further assume that the program includes a monitor procedure with scalar output to determine when it is achieving its performance objectives. The proposed approach collects simulation and real world observations and builds conditional probability functions. These are …

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Synthesis, Characterization, Dna Binding, Topoisomerase Inhibition, And Apoptosis Induction Studies Of A Novel Cobalt(Iii) Complex With A Thiosemicarbazone Ligand, Stephen J. Beebe, Michael J. Celestine, Jimmie L. Bullock, Shayna Sandhaus, Jessa Faye Arca, Donald M. Cropek, Tekettay A. Ludvig, Sydney R. Foster, Jasmine S. Clark, Floyd A. Beckford, Criszcele M. Tano, Elizabeth A. Tonsel-White, Raj K. Gurung, Courtney E. Stankavich, Yuk Ching Tse-Dinh, William L. Jarrett, Alvin A. Holder Feb 2020

Synthesis, Characterization, Dna Binding, Topoisomerase Inhibition, And Apoptosis Induction Studies Of A Novel Cobalt(Iii) Complex With A Thiosemicarbazone Ligand, Stephen J. Beebe, Michael J. Celestine, Jimmie L. Bullock, Shayna Sandhaus, Jessa Faye Arca, Donald M. Cropek, Tekettay A. Ludvig, Sydney R. Foster, Jasmine S. Clark, Floyd A. Beckford, Criszcele M. Tano, Elizabeth A. Tonsel-White, Raj K. Gurung, Courtney E. Stankavich, Yuk Ching Tse-Dinh, William L. Jarrett, Alvin A. Holder

Faculty Publications

In this study, 9-anthraldehyde-N(4)-methylthiosemicarbazone (MeATSC) 1 and [Co(phen)2(O2CO)]Cl·6H2O 2 (where phen = 1,10-phenanthroline) were synthesized. [Co(phen)2(O2CO)]Cl·6H2O 2 was used to produce anhydrous [Co(phen)2(H2O)2](NO3)3 3. Subsequently, anhydrous [Co(phen)2(H2O)2](NO3)3 3 was reacted with MeATSC 1 to produce [Co(phen)2(MeATSC)](NO3)3·1.5H2O·C2H5OH 4. The ligand, MeATSC 1 and all complexes were characterized by elemental analysis, FT IR, UV–visible, and multinuclear NMR ( …

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Radiation-Induced Electron And Hole Traps In Ge1-XSnX (X = 0-0.094), Michael R. Hogsed, Kevin Choe, Norman Miguel, Buguo Wang, John Kouvetakis Feb 2020

Radiation-Induced Electron And Hole Traps In Ge1-XSnX (X = 0-0.094), Michael R. Hogsed, Kevin Choe, Norman Miguel, Buguo Wang, John Kouvetakis

Faculty Publications

The band structure of germanium changes significantly when alloyed with a few percent concentrations of tin, and while much work has been done to characterize and exploit these changes, the corresponding deep-level defect characteristics are largely unknown. In this paper, we investigate the dominant deep-level defects created by 2 MeV proton irradiation in Ge1 -xSnx (x = 0.0, 0.020, 0.053, 0.069, and 0.094) diodes and determine how the ionization energies of these defects change with tin concentrations. Deep-level transient spectroscopy measurements approximate the ionization energies associated with electron transitions to/from the valence band (hole traps) and conduction band (electron traps) …

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Metrics To Meet Security & Privacy Requirements With Agile Software Development Methods In A Regulated Environment, Torrey J. Wagner, Thomas C. Ford Feb 2020

Metrics To Meet Security & Privacy Requirements With Agile Software Development Methods In A Regulated Environment, Torrey J. Wagner, Thomas C. Ford

Faculty Publications

This work examines metrics that can be used to measure the ability of agile software development methods to meet security and privacy requirements of communications applications. Many implementations of communication protocols, including those in vehicular networks, occur within regulated environments where agile development methods are traditionally discouraged. We propose a framework and metrics to measure adherence to security, quality and software effectiveness regulations if developers desire the cost and schedule benefits of agile methods. After providing an overview of specific challenges that a regulated environment imposes on communications software development, we proceed to examine the 12 agile principles and how …

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An Ultra-Sparse Approximation Of Kinetic Solutions To Spatially Homogeneous Flows Of Non-Continuum Gas, Alexander Alekseenko, Amy Grandilli, Aihua W. Wood Feb 2020

An Ultra-Sparse Approximation Of Kinetic Solutions To Spatially Homogeneous Flows Of Non-Continuum Gas, Alexander Alekseenko, Amy Grandilli, Aihua W. Wood

Faculty Publications

We consider a compact approximation of the kinetic velocity distribution function by a sum of isotropic Gaussian densities in the problem of spatially homogeneous relaxation. Derivatives of the macroscopic parameters of the approximating Gaussians are obtained as solutions to a linear least squares problem derived from the Boltzmann equation with full collision integral. Our model performs well for flows obtained by mixing upstream and downstream conditions of normal shock wave with Mach number 3. The model was applied to explore the process of approaching equilibrium in a spatially homogeneous flow of gas. Convergence of solutions with respect to the model …

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A Sequential Partial Information Bomber‐Defender Shooting Problem, Krishna Kalyanam, David W. Casbeer, Meir Pachter Feb 2020

A Sequential Partial Information Bomber‐Defender Shooting Problem, Krishna Kalyanam, David W. Casbeer, Meir Pachter

Faculty Publications

No abstract provided.

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Kinetic Alfvénwaves Frommagnetotail To The Ionosphere In Global Hybrid Simulation Associated With Fast Flows, Lei Cheng, Yu Lin, J. D. Perez, Jay R. Johnson, Xueyi Wang Feb 2020

Kinetic Alfvénwaves Frommagnetotail To The Ionosphere In Global Hybrid Simulation Associated With Fast Flows, Lei Cheng, Yu Lin, J. D. Perez, Jay R. Johnson, Xueyi Wang

Faculty Publications

We have used the Auburn Global Hybrid Code in 3‐D to study the generation, dynamics, and global structure of kinetic Alfvén waves (KAWs) from the magnetotail to the ionosphere. Our results show that KAWs are generated in magnetic reconnection in the plasma sheet, located around fast flows, and carrying transverse electromagnetic perturbations, parallel Poynting fluxes, parallel currents, and parallel electric field. Overall, shear Alfvénic turbulent spectrum is found in the plasma sheet. The KAWs are shear Alfvén waves possessing short perpendicular wavelength with , where is the perpendicular wave number and the ion Larmor radius. The KAWs are identified by …

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Harmonic Equiangular Tight Frames Comprised Of Regular Simplices, Matthew C. Fickus, Courtney A. Schmitt Feb 2020

Harmonic Equiangular Tight Frames Comprised Of Regular Simplices, Matthew C. Fickus, Courtney A. Schmitt

Faculty Publications

An equiangular tight frame (ETF) is a sequence of unit-norm vectors in a Euclidean space whose coherence achieves equality in the Welch bound, and thus yields an optimal packing in a projective space. A regular simplex is a simple type of ETF in which the number of vectors is one more than the dimension of the underlying space. More sophisticated examples include harmonic ETFs which equate to difference sets in finite abelian groups. Recently, it was shown that some harmonic ETFs are comprised of regular simplices. In this paper, we continue the investigation into these special harmonic ETFs. We begin …

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230Th Normalization: New Insights On An Essential Tool For Quantifying Sedimentary Fluxes In The Modern And Quaternary Ocean, Kassandra M. Costa, Christopher T. Hayes, Robert F. Anderson, Frank J. Pavia, Alexandra Bausch, Feifei Deng, Jean Claude Dutay, Walter Geibert, Christoph Heinze, Gideon Henderson, Claude Hillaire-Marcel, Sharon Hoffmann, Samuel L. Jaccard, Allison W. Jacobel, Stephanie S. Kienast, Lauren Kipp, Paul Lerner, Jörg Lippold, David Lund, Franco Marcantonio, David Mcgee, Jerry F. Mcmanus, Figen Mekik, Jennifer L. Middleton, Lise Missiaen, Christelle Not, Sylvain Pichat, Laura F. Robinson, George H. Rowland, Matthieu Roy-Barman, Alessandro Tagliabue, Adi Torfstein, Gisela Winckler, Yuxin Zhou Feb 2020

230Th Normalization: New Insights On An Essential Tool For Quantifying Sedimentary Fluxes In The Modern And Quaternary Ocean, Kassandra M. Costa, Christopher T. Hayes, Robert F. Anderson, Frank J. Pavia, Alexandra Bausch, Feifei Deng, Jean Claude Dutay, Walter Geibert, Christoph Heinze, Gideon Henderson, Claude Hillaire-Marcel, Sharon Hoffmann, Samuel L. Jaccard, Allison W. Jacobel, Stephanie S. Kienast, Lauren Kipp, Paul Lerner, Jörg Lippold, David Lund, Franco Marcantonio, David Mcgee, Jerry F. Mcmanus, Figen Mekik, Jennifer L. Middleton, Lise Missiaen, Christelle Not, Sylvain Pichat, Laura F. Robinson, George H. Rowland, Matthieu Roy-Barman, Alessandro Tagliabue, Adi Torfstein, Gisela Winckler, Yuxin Zhou

Faculty Publications

230Th normalization is a valuable paleoceanographic tool for reconstructing high‐resolution sediment fluxes during the late Pleistocene (last ~500,000 years). As its application has expanded to ever more diverse marine environments, the nuances of 230Th systematics, with regard to particle type, particle size, lateral advective/diffusive redistribution, and other processes, have emerged. We synthesized over 1000 sedimentary records of 230Th from across the global ocean at two time slices, the late Holocene (0–5,000 years ago, or 0–5 ka) and the Last Glacial Maximum (18.5–23.5 ka), and investigated the spatial structure of 230Th‐normalized mass fluxes. On a global scale, …

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