Physical Sciences and Mathematics Commons^™

The Dangers Of Human-Like Bias In Machine-Learning Algorithms, Daniel James Fuchs

Missouri S&T’s Peer to Peer

Machine learning algorithms (MLAGs), frequently used in artificial intelligence (AI), rely on using patterns across sets of data to derive decision-making intelligence. In recent years, as society continues to give increasing authority to ML-driven AIs, these algorithms have demonstrated the ability to take on human-like discriminatory biases. Microsoft's "Tay," for example, a social media-based chatbot, went from resembling a normal teenage girl to displaying racist and sexist attitudes in a mere sixteen hours). Tay and many other ML-driven implementations across a wide variety of fields have replicated numerous human biases. In most cases, these human-like biases originated due to improper …

Nmr Studies Of Loaded Microspheres, Ming Huang, Sisi Chen, Rex E. Gerald Ii, Jie Huang, Klaus Woelk

Electrical and Computer Engineering Faculty Research & Creative Works

Porous-wall hollow glass microspheres (PWHGMs) are a novel form of glass materials that consist of 1-μm-thick porous silica shells, 20-100 μm in diameter, with a hollow cavity in the center. Utilizing the central cavity for material storage and the porous walls for controlled release is a unique combination that renders PWHGMs a superior vehicle for targeted drug delivery. In this study, NMR spectroscopy was used to characterize PWHGMs for the first time. A vacuum-based loading system was developed to load PWHGMs with various compounds followed by a washing procedure that uses solvents immiscible with the target material. Immiscible binary model …

Characteristics Of The Mantle Flow System Beneath The Indochina Peninsula Revealed By Teleseismic Shear Wave Splitting Analysis, Youqiang Yu, Stephen S. Gao, Kelly H. Liu, Ting Yang, Mei Xue, Khanh Phon Le, Jinyao Gao

Geosciences and Geological and Petroleum Engineering Faculty Research & Creative Works

Numerous geoscientific investigations have been conducted on the southeastern Tibetan Plateau and adjacent areas for understanding crustal and mantle deformation associated with the indentation of the Indian Plate into Eurasia. A number of key issues, such as the causes of a sudden change of fast polarization orientations from N-S to almost E-W at approximately 26°N revealed by shear wave splitting (SWS) studies, and the geodynamic implications of the transition still remain enigmatic, partially due to the lack of sufficient SWS measurements on the Indochina Peninsula. Here we employ the SWS technique to systematically illuminate upper mantle anisotropy beneath the Indochina …

Full Band All-Sky Search For Periodic Gravitational Waves In The O1 Ligo Data, Benjamin P. Abbott, Marco Cavaglia, For Full List Of Authors, See Publisher's Website.

Physics Faculty Research & Creative Works

We report on a new all-sky search for periodic gravitational waves in the frequency band 475-2000 Hz and with a frequency time derivative in the range of [-1.0,+0.1] x 10^-8 Hz/s. Potential signals could be produced by a nearby spinning and slightly nonaxisymmetric isolated neutron star in our Galaxy. This search uses the data from Advanced LIGO's first observational run O1. No gravitational-wave signals were observed, and upper limits were placed on their strengths. For completeness, results from the separately published low-frequency search 20-475 Hz are included as well. Our lowest upper limit on worst-case (linearly polarized) strain amplitude …

Constraints On Cosmic Strings Using Data From The First Advanced Ligo Observing Run, Benjamin P. Abbott, Marco Cavaglia, For Full List Of Authors, See Publisher's Website.

Physics Faculty Research & Creative Works

Cosmic strings are topological defects which can be formed in grand unified theory scale phase transitions in the early universe. They are also predicted to form in the context of string theory. The main mechanism for a network of Nambu-Goto cosmic strings to lose energy is through the production of loops and the subsequent emission of gravitational waves, thus offering an experimental signature for the existence of cosmic strings. Here we report on the analysis conducted to specifically search for gravitational-wave bursts from cosmic string loops in the data of Advanced LIGO 2015-2016 observing run (O1). No evidence of such …

Search For Tensor, Vector, And Scalar Polarizations In The Stochastic Gravitational-Wave Background, Benjamin P. Abbott, Marco Cavaglia, For Full List Of Authors, See Publisher's Website.

Physics Faculty Research & Creative Works

The detection of gravitational waves with Advanced LIGO and Advanced Virgo has enabled novel tests of general relativity, including direct study of the polarization of gravitational waves. While general relativity allows for only two tensor gravitational-wave polarizations, general metric theories can additionally predict two vector and two scalar polarizations. The polarization of gravitational waves is encoded in the spectral shape of the stochastic gravitational-wave background, formed by the superposition of cosmological and individually unresolved astrophysical sources. Using data recorded by Advanced LIGO during its first observing run, we search for a stochastic background of generically polarized gravitational waves. We find …

Dark-Bright Soliton Pairs: Bifurcations And Collisions, Garyfallia C. Katsimiga, P. G. Kevrekidis, B. Prinari, G. Biondini, P. Schmelcher

Physics Faculty Research & Creative Works

The statics, stability, and dynamical properties of dark-bright soliton pairs are investigated here, motivated by applications in a homogeneous two-component repulsively interacting Bose-Einstein condensate. One of the intraspecies interaction coefficients is used as the relevant parameter controlling the deviation from the integrable Manakov limit. Two different families of stationary states are identified consisting of dark-bright solitons that are either antisymmetric (out-of-phase) or asymmetric (mass imbalanced) with respect to their bright soliton. Both of the above dark-bright configurations coexist at the integrable limit of equal intra and interspecies repulsions and are degenerate in that limit. However, they are found to bifurcate …

Reduction Of The Ordered Magnetic Moment And Its Relationship To Kondo Coherence In Ce₁₋ₓlaₓcu₂Ge₂, B. G. Ueland, N. H. Jo, A. Sapkota, W. Tian, M. Masters, Halyna Hodovanets, S. S. Downing, C. Schmidt, R. J. Mcqueeney, For Full List Of Authors, See Publisher's Website.

Physics Faculty Research & Creative Works

The microscopic details of the suppression of antiferromagnetic order in the Kondo-lattice series Ce_1-xLa_xCu₂Ge₂ due to nonmagnetic dilution by La are revealed through neutron diffraction results for x = 0.20, 0.40, 0.75, and 0.85. Magnetic Bragg peaks are found for 0.20 ≤ x ≤ 0.75, and both the Néel temperature TN and the ordered magnetic moment per Ce μ linearly decrease with increasing x. The reduction in μ points to strong hybridization of the increasingly diluted Ce 4f electrons, and we find a remarkable quadratic dependence of μ on the Kondo-coherence temperature. We …

Spectral Analysis Of Surface Waves To Detect Subsurface Voids, Payman Hajiani, Neil Lennart Anderson, J. David Rogers

Geosciences and Geological and Petroleum Engineering Faculty Research & Creative Works

Systems and methods for detecting a subsurface cavity. A source applies a force to ground under inspection and a plurality of sensors coupled to the ground detect resulting surface waves. A processor is configured to extract phase and frequency components of the acquired seismic data, identify a phase shift in surface waves in the ground under inspection based on the extracted phase and frequency components, and determine one or more physical characteristics of a subsurface cavity based on the identified phase shift

Beyond Triplet: Unconventional Superconductivity In A Spin-3/2 Topological Semimetal, Hyunsoo Kim, Kefeng Wang, Yasuyuki Nakajima, Rongwei Hu, Steven Ziemak, Paul Syers, Limin Wang, Halyna Hodovanets, Jonathan D. Denlinger, For Full List Of Authors, See Publisher's Website.

Physics Faculty Research & Creative Works

In all known fermionic superfluids, Cooper pairs are composed of spin-1/2 quasi-particles that pair to form either spin-singlet or spin-triplet bound States. The "spin" of a Bloch electron, however, is fixed by the symmetries of the crystal and the atomic orbitals from which it is derived and, in some cases, can behave as if it were a spin-3/2 particle. The superconducting state of such a system allows pairing beyond spin-triplet, with higher spin quasi-particles combining to form quintet or septet pairs. We report evidence of unconventional superconductivity emerging from a spin-3/2 quasi-particle electronic structure in the half-Heusler semimetal YPtBi, a …

Epoxy Phosphonate Ester As A Coupling Agent For Transition Metal And Metal Oxide Surfaces, Thomas P. Schuman

Chemistry Faculty Research & Creative Works

A method for surface modification of a substrate comprising surface oxide and/or hydroxy groups, with a compound comprising an ester group and an epoxy ring, wherein the epoxy group remains intact after the reacting. A method for surface modification of a substrate comprising surface oxide and/or hydroxy groups, with a compound comprising an ester group and a functionalized epoxy ring, wherein the functionalized epoxy group remains intact after the reacting. A composite material comprising surface-modified metal oxide nanoparticles dispersed within a polymeric material, wherein the surface modification comprises a compound comprising an ester group and an epoxy ring is also …

Improving The Total Organic Carbon Estimation Of The Eagle Ford Shale With Density Logs By Considering The Effect Of Pyrite, Shuxian Jiang, Mehdi Mokhtari, David M. Borrok, Jim Lee

Geosciences and Geological and Petroleum Engineering Faculty Research & Creative Works

Pyrite is a common mineral with a higher density than most other minerals in the Eagle Ford Shale formation. Hence, if pyrite is not considered in the total organic carbon (TOC) estimation, based on density logs, it may lead to errors. In order to improve the accuracy of the TOC estimation, we propose an updated TOC estimation method that incorporates the concentration of pyrite and organic porosity. More than 15 m of Eagle Ford Shale samples were analyzed using Rock-Eval pyrolysis, X-ray fluorescence (XRF), and X-ray diffraction (XRD). TOC, elemental concentration, and mineralogical data were analyzed for a better understanding …

A Multi-Step Nonlinear Dimension-Reduction Approach With Applications To Bigdata, R. Krishnan, V. A. Samaranayake, Jagannathan Sarangapani

Mathematics and Statistics Faculty Research & Creative Works

In this paper, a multi-step dimension-reduction approach is proposed for addressing nonlinear relationships within attributes. In this work, the attributes in the data are first organized into groups. In each group, the dimensions are reduced via a parametric mapping that takes into account nonlinear relationships. Mapping parameters are estimated using a low rank singular value decomposition (SVD) of distance covariance. Subsequently, the attributes are reorganized into groups based on the magnitude of their respective singular values. The group-wise organization and the subsequent reduction process is performed for multiple steps until a singular value-based user-defined criterion is satisfied. Simulation analysis is …

Direct Error Driven Learning For Deep Neural Networks With Applications To Bigdata, R. Krishnan, Jagannathan Sarangapani, V. A. Samaranayake

Electrical and Computer Engineering Faculty Research & Creative Works

In this paper, generalization error for traditional learning regimes-based classification is demonstrated to increase in the presence of bigdata challenges such as noise and heterogeneity. To reduce this error while mitigating vanishing gradients, a deep neural network (NN)-based framework with a direct error-driven learning scheme is proposed. To reduce the impact of heterogeneity, an overall cost comprised of the learning error and approximate generalization error is defined where two NNs are utilized to estimate the costs respectively. To mitigate the issue of vanishing gradients, a direct error-driven learning regime is proposed where the error is directly utilized for learning. It …

Correlation Effects In The Quench-Induced Phase Separation Dynamics Of A Two Species Ultracold Quantum Gas, Simeon I. Mistakidis, Garyfallia C. Katsimiga, P. G. Kevrekidis, P. Schmelcher

Physics Faculty Research & Creative Works

We Explore The Quench Dynamics Of A Binary Bose-Einstein Condensate Crossing The Miscibility-Immiscibility Threshold And Vice Versa, Both Within And In Particular Beyond The Mean-Field Approximation. Increasing The Interspecies Repulsion Leads To The Filamentation Of The Density Of Each Species, Involving Shorter Wavenumbers And Longer Spatial Scales In The Many-Body (MB) Approach. These Filaments Appear To Be Strongly Correlated And Exhibit Domain-Wall Structures. Following The Reverse Quench Process Multiple Dark-Antidark Solitary Waves Are Spontaneously Generated And Subsequently Found To Decay In The MB Scenario. We Simulate Single-Shot Images To Connect Our Findings To Possible Experimental Realizations. Finally, The Growth Rate …

Atomic Physics Constraints On The X Boson, Ulrich D. Jentschura, Istvan Nandori

Physics Faculty Research & Creative Works

Recently, a peak in the light fermion pair spectrum at invariant q)² ≈ (16.7MeV)² has been observed in the bombardment of ⁷Li by protons. This peak has been interpreted in terms of a protophobic interaction of fermions with a gauge boson (X boson) of invariant mass ≈16.7MeV which couples mainly to neutrons. High-precision atomic physics experiments aimed at observing the protophobic interaction need to separate the X boson effect from the nuclear-size effect, which is a problem because of the short range of the interaction (11.8 fm), which is commensurate with a "nuclear halo." Here we analyze …

Following Coherent Multichannel Nuclear Wave Packets In Pump-Probe Studies Of O₂ With Ultrashort Laser Pulses, S. Xue, H. Du, B. Hu, C. D. Lin, Anh-Thu Le

Physics Faculty Research & Creative Works

We reexamine the recent pump-probe experiment with O₂ using short intense infrared laser pulses theoretically. Using parameters that closely mimic the experimental conditions and taking into account the angle-dependent population redistribution due to resonant coupling between the relevant states, we show that the observed kinetic energy release spectra, including the energy-dependent structure and the quantum beat frequencies, can be accurately reproduced. Our results reveal additional important channels that were missed earlier. In particular, the strong contributions from O₂+a⁴Π_u and b⁴Σ_b- states lead to the possibility of observing the interchannel beating. We further demonstrate …

All-Optical Atom Trap As A Target For Motrims-Like Collision Experiments, S. Sharma, B. P. Acharya, Daniel Fischer, For Full List Of Authors, See Publisher's Website.

Physics Faculty Research & Creative Works

Momentum-resolved scattering experiments with laser-cooled atomic targets have been performed since almost two decades with magneto-optical trap recoil ion momentum spectroscopy (MOTRIMS) setups. Compared to experiments with gas-jet targets, MOTRIMS features significantly lower target temperatures allowing for an excellent recoil ion momentum resolution. However, the coincident and momentum-resolved detection of electrons was long rendered impossible due to incompatible magnetic field requirements. Here we report on an experimental approach which is based on an all-optical ⁶Liatom trap that--in contrast to magneto-optical traps--does not require magnetic field gradients in the trapping region. Atom temperatures of about 2 mK and number densities …

Platy Galena From The Viburnum Trend, Southeast Missouri: Character, Mine Distribution, Paragenetic Position, Trace Element Content, Nature Of Twinning, And Conditions Of Formation, Richard D. Hagni

Geosciences and Geological and Petroleum Engineering Faculty Research & Creative Works

The Viburnum Trend of southeast Missouri is one of the world’s largest producers of lead. The lead occurs as galena, predominantly in two crystallographic forms, octahedrons and cubes. Many studies have shown that octahedral galena is paragentically early, the more abundant of the two crystal forms, and is commonly modified in the cube. Those studies also have shown that the cubic form is paragenetically later, less abundant than the octahedrons, and may exhibit minor octahedral modifications. Viburnum Trend galena crystals that exhibit a platy form have received almost no study. The reason for their lack of study is the rarity …

Approximation Degree Of Durrmeyer-Bézier Type Operators, Purshottam N. Agrawal, Serkan Araci, Martin Bohner, Kumari Lipi

Mathematics and Statistics Faculty Research & Creative Works

Recently, a mixed hybrid operator, generalizing the well-known Phillips operators and Baskakov-Szász type operators, was introduced. In this paper, we study Bézier variant of these new operators. We investigate the degree of approximation of these operators by means of the Lipschitz class function, the modulus of continuity, and a weighted space. We study a direct approximation theorem by means of the unified Ditzian-Totik modulus of smoothness. Furthermore, the rate of convergence for functions having derivatives of bounded variation is discussed.

Software Engineering: Guest Editor's Introduction, Bruce M. Mcmillin

Computer Science Faculty Research & Creative Works

Engineering complex systems requires an extensive technical and semantic knowledge. Because of their complexity, components of these systems can interact in unpredictable ways -- sequentially and concurrently….

The three papers in this theme issue have the potential to address the design challenges of complex systems spanning multiple domains and interacting in potentially unexpected ways. The knowledge required goes beyond basic computing concepts and design, to include an examination of interactions and multiple aspects of the application domain. We hope you find these articles interesting and insightful.

Rapid Adsorption Of Proinflammatory Cytokines By Graphene Nanoplatelets And Their Composites For Extracorporeal Detoxification, Yishan Zheng, Nicholas Pescatore, Yury Gogotsi, Boris Dyatkin, Ganesh Ingavle, Vadym Mochalin, Tochukwu Ozulumba, Sergey Mikhalovsky, Susan Sandeman

Chemistry Faculty Research & Creative Works

Sepsis is a complex clinical syndrome that features excessive release of cytokines and other inflammatory mediators that could lead to organ dysfunction. Despite different treatment and management options, sepsis associated high morbidity and mortality rates remain. This has prompted intensive research into alternative therapeutic approaches such as targeted removal of sepsis related molecules using extracorporeal hemoperfusion. In this study, we explore the use of graphene nanoplatelets (GNP) as low-cost alternative hemosorbents for rapid removal of a broad spectrum of proinflammatory cytokine markers. Firstly, the physical characteristics, cytotoxicity, and cytokine marker adsorption profile of GNP were assessed. The results not only …

Gw170817: Implications For The Stochastic Gravitational-Wave Background From Compact Binary Coalescences, Benjamin P. Abbott, Marco Cavaglia, For Full List Of Authors, See Publisher's Website.

Physics Faculty Research & Creative Works

The LIGO Scientific and Virgo Collaborations have announced the event GW170817, the first detection of gravitational waves from the coalescence of two neutron stars. The merger rate of binary neutron stars estimated from this event suggests that distant, unresolvable binary neutron stars create a significant astrophysical stochastic gravitational-wave background. The binary neutron star component will add to the contribution from binary black holes, increasing the amplitude of the total astrophysical background relative to previous expectations. In the Advanced LIGO-Virgo frequency band most sensitive to stochastic backgrounds (near 25 Hz), we predict a total astrophysical background with amplitude Ω_GW( …

Femtosecond Laser Mass Spectrometry And High Harmonic Spectroscopy Of Xylene Isomers, Abdullah Alharbi, Andrewy E. Boguslavskiy, Dane Austin, Nicolas Thire, D. Wood, P. Hawkins, Felicity Mcgrath, A. S. Johnson, I. Lopez-Quintas, Bruno Schmidt, Francois Legare, J. P. Marangos, Anh-Thu Le, Ravi Bhardwaj

Physics Faculty Research & Creative Works

Structural isomers, molecules having the same chemical formula but with atoms bonded in different order, are hard to identify using conventional spectroscopy and mass spectrometry. They exhibit virtually indistinguishable mass spectra when ionized by electrons. Laser mass spectrometry based on photoionization of the isomers has emerged as a promising alternative but requires shaped ultrafast laser pulses. Here we use transform limited femtosecond pulses to distinguish the isomers using two methods. First, we probe doubly charged parent ions with circularly polarized light. We show that the yield of doubly charged ortho-xylene decreases while para-xylene increases over a range of laser intensities …

Phytoforensics: Trees As Bioindicators Of Potential Indoor Exposure Via Vapor Intrusion, Jordan L. Wilson, V. A. Samaranayake, Matt A. Limmer, Joel Gerard Burken

Mathematics and Statistics Faculty Research & Creative Works

Human exposure to volatile organic compounds (VOCs) via vapor intrusion (VI) is an emerging public health concern with notable detrimental impacts on public health. Phytoforensics, plant sampling to semi-quantitatively delineate subsurface contamination, provides a potential non-invasive screening approach to detect VI potential, and plant sampling is effective and also time- and cost-efficient. Existing VI assessment methods are time- and resource-intensive, invasive, and require access into residential and commercial buildings to drill holes through basement slabs to install sampling ports or require substantial equipment to install groundwater or soil vapor sampling outside the home. Tree-core samples collected in 2 days at …

Fractional Brownian Motion With A Reflecting Wall, Alexander H. O. Wada, Thomas Vojta

Physics Faculty Research & Creative Works

Fractional Brownian motion, a stochastic process with long-time correlations between its increments, is a prototypical model for anomalous diffusion. We analyze fractional Brownian motion in the presence of a reflecting wall by means of Monte Carlo simulations. Whereas the mean-square displacement of the particle shows the expected anomalous diffusion behavior (x²) ~ t^α, the interplay between the geometric confinement and the long-time memory leads to a highly non-Gaussian probability density function with a power-law singularity at the barrier. In the superdiffusive case α > 1, the particles accumulate at the barrier leading to a divergence of the …

Seismic Anisotropy And The Mantle Dynamics Beneath The Arabian Plate, Saleh Ismail Hassan Qaysi

Doctoral Dissertations

"We investigate mantle seismic azimuthal anisotropy and deformation beneath the Arabian Plate and adjacent areas using data from 182 broadband seismic stations which include 157 stations managed by the Saudi Geological Survey. A total of about 4000 pairs of shear wave splitting parameters are obtained using the transverse minimization technique. The individual XKS (including PKS, SKS, and SKKS) splitting measurements were manually checked to ensure the quality. The well-defined parameters show dominantly N-S fast orientations at the majority of the stations, and NW-SE fast orientations along the Zagras Mountain front. No clear systematic variations of the splitting parameters as a …

Mini Review: A Note On Nonoscillatory Solutions For Higher Dimensional Time Scale Systems, Elvan Akin, Ozkan Ozturk, Ismail Ugur Tiryaki, Gulsah Yeni

Mathematics and Statistics Faculty Research & Creative Works

In this paper, we focus on nonoscillatory solutions of two (2D) and three (3D) dimensional time scale systems and discuss nonexistence of such solutions.

The Generalized Hypergeometric Difference Equation, Martin Bohner, Tom Cuchta

Mathematics and Statistics Faculty Research & Creative Works

A difference equation analogue of the generalized hypergeometric differential equation is defined, its contiguous relations are developed, and its relation to numerous well-known classical special functions are demonstrated.

A Higher-Order Ensemble/Proper Orthogonal Decomposition Method For The Nonstationary Navier-Stokes Equations, Max Gunzburger, Nan Jiang, Michael Schneier

Mathematics and Statistics Faculty Research & Creative Works

Partial differential equations (PDE) often involve parameters, such as viscosity or density. An analysis of the PDE may involve considering a large range of parameter values, as occurs in uncertainty quantification, control and optimization, inference, and several statistical techniques. The solution for even a single case may be quite expensive; whereas parallel computing may be applied, this reduces the total elapsed time but not the total computational effort. In the case of flows governed by the Navier-Stokes equations, a method has been devised for computing an ensemble of solutions. Recently, a reduced-order model derived from a proper orthogonal decomposition (POD) …