Physical Sciences and Mathematics Commons^™

The Arecibo Observatory As An Instrument For Investigating Orbital Debris: Legacy And Next Generation Performance, James Murray, Fredrick A. Jenet

Physics and Astronomy Faculty Publications and Presentations

In this paper, we investigate the ability of the Arecibo Observatory to characterize the orbital debris environment and compare it to the primary instrument used by NASA's Orbital Debris Program Office, the Haystack Ultra-Wideband Satellite Imaging Radar (HUSIR). Arecibo's location (183 N) increases the percentage of observable orbits (relative to HUSIR) by 27%, which gives Arecibo access to a much larger and previously unmeasured portion of the environment. Due to the recent collapse of the Arecibo dish, in addition to exploring historic capabilities of the Legacy Arecibo Telescope, estimates of the performance of the proposed Next Generation Arecibo Telescope (NGAT) …

Now You See Me: “First” Records Of The Greater Amberjack Seriola Dumerili At Rapa Nui Range Extension Or Increased Scientific Effort?, Naiti Morales, Amy Rose Coghlan, Erin E. Easton, Alan M. Friedlander, James J. Herlan, Carlos F. Gaymer

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

We report new records of the fisheries-harvested subtropical greater amberjack Seriola dumerili for the south-east Pacific Ocean. Previously, only one species of Seriola (the yellowtail amberjack Seriola lalandi) was scientifically recorded for Rapa Nui (also known as Easter Island) despite local fishers' asserting that three Seriola morphotypes are found in the region. Here we present the first 'scientific record' of what could be a pre-existing (albeit transient) species of the Rapa Nui ecoregion. Establishing the existing range limits of commercially and ecologically valuable species is key for observing climate-driven distribution shifts, and the inclusion of traditional ecological knowledge is likely …

Robots Need The Ability To Navigate Abusive Interactions, Hideki Garcia Goo, Katie Winkle, Tom Williams, Megan K. Strait

Computer Science Faculty Publications and Presentations

Researchers are seeing more and more cases of abusive disinhibition towards robots in public realms. Because robots embody gendered identities, poor navigation of antisocial dynamics may reinforce or exacerbate gender-based violence. It is essential that robots deployed in social settings be able to recognize and respond to abuse in a way that minimises ethical risk. Enabling this capability requires designers to first understand the risk posed by abuse of robots, and hence how humans perceive robot-directed abuse. To that end, we experimentally investigated reactions to a physically abusive interaction between a human perpetrator and a victimized agent. Given extensions of …

Comparative Assessment Of Pollutant Concentrations And Meteorological Parameters From Tceq Cams Sites At Houston And Rio Grande Valley Regions Of Texas, Usa In 2016, Esmeralda Mendez, Jonathan Rodriguez, August Luna, Amit U. Raysoni

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

Spatial and temporal heterogeneity in pollutant concentrations exists at the intra-urban level. In this research work, the concentrations of various pollutants and meteorological parameters are characterized between various central ambient monitoring sites at Houston, TX, and the Rio Grande Valley Regions of South Texas. Meteorological (temperature, relative humidity, wind speed and direction) and pollutant (O3, SO2, CO, NO2, and various PM species) concentrations were downloaded from the appropriate Texas Commission on Environmental Quality (TCEQ) Central Ambient Monitoring Station (CAMS) sites for the year 2016. Correlation Analyses and Coefficient of Divergence (COD) analyses suggest that statistically significant differences occur between the …

Comparative Evaluation Of Physicochemical And Fermentative Responses Of Three Sorghum Varieties From Dryland And Irrigated Land And The Properties Of Proteins From Distillers’ Grains, Jikai Zhao, Thomas Weiss, Zhenjiao Du, Shan Hong, Scott R. Bean, Yonghui Li, Donghai Wang

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

Three sorghum varieties [waxy sorghum (WS), high protein sorghum (HPS), and normal sorghum (NS)] grown under dryland and irrigated conditions were evaluated with respect to the physicochemical and fermentative properties. The proteins were extracted from wet distillers' grains with solubles (WDGS) and characterized in terms of purity and in vitro digestibility. Starch, crude protein, crude fat, and fiber contents of the sorghums ranged from 64.16 to 68.05 g/100 g, 11.49–13.54 g/100 g, 2.45–2.98 g/100 g, and 1.62–1.80 g/100 g, respectively. For the same variety, the sorghums grown under dryland conditions had higher protein (0.33–0.91 g/100 g) and lower …

Number Of Bounded Distance Equivalence Classes In Hulls Of Repetitive Delone Sets, Dirk Frettlöh, Alexey Garber, Lorenzo Sadun

School of Mathematical and Statistical Sciences Faculty Publications and Presentations

Two Delone sets are bounded distance equivalent to each other if there is a bijection between them such that the distance of corresponding points is uniformly bounded. Bounded distance equivalence is an equivalence relation. We show that the hull of a repetitive Delone set with finite local complexity has either one equivalence class or uncountably many.

Optimal Quantization For Mixed Distributions Generated By Two Uniform Distributions, Ashley Gomez, Olga Lopez, Mrinal Kanti Roychowdhury

School of Mathematical and Statistical Sciences Faculty Publications and Presentations

In this paper, for mixed distributions generated by two uniform distributions we investigate the optimal sets of n-means and the nth quantization errors for all positive integers n. Some conjectures and open problems are also given.

Search For Intermediate-Mass Black Hole Binaries In The Third Observing Run Of Advanced Ligo And Advanced Virgo, R. Abbott, T. D. Abbott, F. Acernese, K. Ackley, C. Adams, Teviet Creighton, Mario C. Diaz, Soma Mukherjee, Volker Quetschke, Wenhui Wang

Physics and Astronomy Faculty Publications and Presentations

Intermediate-mass black holes (IMBHs) span the approximate mass range 100−10⁵ M_⊙, between black holes (BHs) that formed by stellar collapse and the supermassive BHs at the centers of galaxies. Mergers of IMBH binaries are the most energetic gravitational-wave sources accessible by the terrestrial detector network. Searches of the first two observing runs of Advanced LIGO and Advanced Virgo did not yield any significant IMBH binary signals. In the third observing run (O3), the increased network sensitivity enabled the detection of GW190521, a signal consistent with a binary merger of mass ∼150 M_⊙ providing direct evidence of …

Deep Learning Model With Adaptive Regularization For Eeg-Based Emotion Recognition Using Temporal And Frequency Features, Alireza Samavat, Ebrahim Khalili, Bentolhoda Ayati, Marzieh Ayati

Computer Science Faculty Publications and Presentations

Since EEG signal acquisition is non-invasive and portable, it is convenient to be used for different applications. Recognizing emotions based on Brain-Computer Interface (BCI) is an important active BCI paradigm for recognizing the inner state of persons. There are extensive studies about emotion recognition, most of which heavily rely on staged complex handcrafted EEG feature extraction and classifier design. In this paper, we propose a hybrid multi-input deep model with convolution neural networks (CNNs) and bidirectional Long Short-term Memory (Bi-LSTM). CNNs extract time-invariant features from raw EEG data, and Bi-LSTM allows long-range lateral interactions between features. First, we propose a …

Multi-Breather Solutions To The Sasa-Satsuma Equation, Chengfa Wu, Bo Wei, Changyan Shi, Bao-Feng Feng

School of Mathematical and Statistical Sciences Faculty Publications and Presentations

General breather solution to the Sasa-Satsuma (SS) equation is systematically investigated in this paper. We firstly transform the SS equation into a set of three Hirota bilinear equations under proper plane wave background. Starting from a specially arranged tau-function of the Kadomtsev-Petviashvili hierarchy and a set of eleven bilinear equations satisfied, we implement a series steps of reduction procedure, i.e., C-type reduction, dimension reduction and complex conjugate reduction, and reduce these eleven equations to three bilinear equations for the SS equation. Meanwhile, general breather solution to the SS equation is found in determinant of even order. The one- and two-breather …

A Skateboarding Experiential Learning Activity For Introductory Physics, Liang Zeng, Guang Zeng, Oscar Guerrero, George Garcia

Physics and Astronomy Faculty Publications and Presentations

Instructors of introductory college physics courses are in a unique position to explain the physics of skateboarding and its associated risks. A field trip to a skate park to explore the law of conservation of energy and measure the impact forces can enhance student analytical thinking skills and their appreciation of physics in everyday life. Through the measurement of the impact forces and student discussions of their own skateboarding experiences, students are better prepared to protect themselves from skateboarding-related physical injuries. Due to its flexible and creative nature, skateboarding has become a popular action sport worldwide. In the United States, …

Reducing Adverse Impacts Of Amazon Hydropower Expansion, Alexander S. Flecker, Qinru Shi, Rafael M. Almeida, Héctor Angarita, Jonathan M. Gomes-Selman, Roosevelt García-Villacorta, Suresh A. Sethi, Steven A. Thomas, N Leroy Poff, Bruce R. Forsberg

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

Proposed hydropower dams at more than 350 sites throughout the Amazon require strategic evaluation of trade-offs between the numerous ecosystem services provided by Earth's largest and most biodiverse river basin. These services are spatially variable, hence collective impacts of newly built dams depend strongly on their configuration. We use multiobjective optimization to identify portfolios of sites that simultaneously minimize impacts on river flow, river connectivity, sediment transport, fish diversity, and greenhouse gas emissions while achieving energy production goals. We find that uncoordinated, dam-by-dam hydropower expansion has resulted in forgone ecosystem service benefits. Minimizing further damage from hydropower development requires considering …

Differential Privacy In Privacy-Preserving Big Data And Learning: Challenge And Opportunity, Honglu Jiang, Yifeng Gao, S. M. Sarwar, Luis Garza Perez, Mahmudul Robin

Computer Science Faculty Publications and Presentations

Differential privacy (DP) has become the de facto standard of privacy preservation due to its strong protection and sound mathematical foundation, which is widely adopted in different applications such as big data analysis, graph data process, machine learning, deep learning, and federated learning. Although DP has become an active and influential area, it is not the best remedy for all privacy problems in different scenarios. Moreover, there are also some misunderstanding, misuse, and great challenges of DP in specific applications. In this paper, we point out a series of limits and open challenges of corresponding research areas. Besides, we offer …

Surface Modified Hybrid Znsno3 Nanocubes For Enhanced Piezoelectric Power Generation And Wireless Sensory Application, Sk Md Ali Zaker Shawon, Zaida D. Carballo, Valeria Suarez Vega, Chen Lin, Muhammad Sufian Rafaqut, Andrew Xu Sun, James Li, Mohammed Jasim Uddin

Chemistry Faculty Publications and Presentations

Piezoelectric Nanogenerators (PENGs), which can convert ambient mechanical stimuli into electrical energy, are held in high regard due to their cost-effectiveness, energy harvesting applications, and potential as self-powered sensors. We report an aluminum-doped zinc stannate (ZnSnO3) PENG that can achieve high electrical outputs with respect to the external force. In order to enrich the piezoelectric mechanics, a low-temperature solution method was adopted in our work to synthesize ZnSnO3 nanocubes with an average side length of only 30 – 55 nm. Furthermore, ZnSnO3 was doped with 1 wt% to 5 wt% of aluminum nanoparticles. We report that 2 wt% of aluminum …

Wallaby Pilot Survey: H I Gas Disc Truncation And Star Formation Of Galaxies Falling Into The Hydra I Cluster, T. N. Reynolds, B. Catinella, L. Cortese, Tobias Westmeier, G. R. Meurer, L. Shao, D. Obreschkow, J. Román, L. Verdes-Montenegro, Juan P. Madrid

Physics and Astronomy Faculty Publications and Presentations

We present results from our analysis of the Hydra I cluster observed in neutral atomic hydrogen (HI) as part of the Widefield ASKAP L-band Legacy All-sky Blind Survey (WALLABY). These WALLABY observations cover a 60-square-degree field of view with uniform sensitivity and a spatial resolution of 30 arcsec. We use these wide-field observations to investigate the effect of galaxy environment on HI gas removal and star formation quenching by comparing the properties of cluster, infall and field galaxies extending up to ∼5R200 from the cluster centre. We find a sharp decrease in the HI-detected fraction of infalling galaxies at a …

Euclidean Quantum Field Formulation Of P-Adic Open String Amplitudes, A. R. Fuquen-Tibatá, H. García-Compeán, Wilson A. Zuniga-Galindo

School of Mathematical and Statistical Sciences Faculty Publications and Presentations

We study in a rigorous mathematical way p-adic quantum field theories whose N-point amplitudes are the expectation of products of vertex operators. We show that this type of amplitudes admit a series expansion where each term is an Igusa's local zeta function. The lowest term in this series is a regularized version of the p-adic open Koba-Nielsen string amplitude.

Identifying Available Resources And Agricultural Practices Useful In Soil Fertility Management To Support Orange-Fleshed Sweet Potato Cultivation On Smallholder Farms In Mozambique, Rafaela Feola Conz, Engil Isadora Pujol Pereira, Abdul Naico, Maria Isabel Andrade, Johan Six

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

Orange-fleshed sweet potato is an important source of macro-and micronutrients for humans, particularly in resource-poor rural communities. However, sweet potato cultivation removes large amounts of nutrients from the soil. Hence, soil fertility replenishment is vital to secure long-term food production. The lack of access to fertilizers hinders the ability of farmers to supply and replenish soil nutrients, intensifying food insecurity. This study aimed at identifying locally available organic residues and agricultural practices with potential application in soil fertility management to prevent soil degradation in southern Mozambique. We conducted a survey to gather information on the farmers’ demographics and farming systems …

The Reduced Order Method For Solving The Linear Complementarity Problem With An M-Matrix, Xi-Ming Fang, Heng-Jun Zhao, Zhijun Qiao

School of Mathematical and Statistical Sciences Faculty Publications and Presentations

In this paper, by seeking the zero and the positive entry positions of the solution, we provide a direct method, called the reduced order method, for solving the linear complementarity problem with an M-matrix. By this method, the linear complementarity problem is transformed into a low order linear complementarity problem with some low order linear equations and the solution is constructed by the solution of the low order linear complementarity problem and the solutions of these low order linear equations in the transformations. In order to show the accuracy and the effectiveness of the method, the corresponding numerical experiments …

Affect Graphing: Leveraging Graphical Representations In The Study Of Students’ Affect In Mathematics, V. Rani Satyam, Younggon Bae, John P. Smith Iii, Mariana Levin

School of Mathematical and Statistical Sciences Faculty Publications and Presentations

Affect (e.g., beliefs, attitudes, emotions) plays a crucial role in mathematics learning, but reliance on verbal and written responses (from surveys, interviews, etc.) limits students’ expression of their affective states. As a complement to existing methods that rely on verbal reports, we explore how graphing can be used to study affect during mathematical experiences. We analyze three studies that used graphing to represent, stimulate recall, and reflect on affect. In each, students were asked to draw their perception of an affective construct, such as confidence or intensity of emotion, against time. The studies differed in participant populations, target affect, timescales …

Flexible Bielectrode-Based Highly Sensitive Triboelectric Motion Sensor: A Sustainable And Smart Electronic Material, Damian Zamora, Abu Masa Abdullah, Alejandro Flores, Haimanti Majumder, Muhtasim Ul Karim Sadaf, Bahareh Azimi, Serena Danti, M. Jasim Uddin

Chemistry Faculty Publications and Presentations

The self-powered and autonomous sensors are incredibly important in advanced engineering, especially defence science. The increasing necessity of simple and smart electronics requires to be sustainably flexible, wearable, and waterproof. Triboelectricity has been a widely used mechanism for motion sensing nowadays. Almost all devices based on triboelectricity require contact between two surfaces. Herein, a touchless triboelectric motion sensor for human motion sensing and movement monitoring is developed. The device was primarily fabricated using simple latex (cis-1,4-polyisoprene) structures and copper (electrode materials), which make it a very cost-effective device for sensory applications. The device is tested with specimens of different areas …

Search For Continuous Gravitational Waves From 20 Accreting Millisecond X-Ray Pulsars In O3 Ligo Data, R. Abbott, T. D. Abbott, F. Acernese, K. Ackley, C. Adams, Teviet Creighton, Mario C. Diaz, F. Llamas, Soma Mukherjee, Volker Quetschke, W. H. Wang

Physics and Astronomy Faculty Publications and Presentations

Results are presented of searches for continuous gravitational waves from 20 accreting millisecond x-ray pulsars with accurately measured spin frequencies and orbital parameters, using data from the third observing run of the Advanced LIGO and Advanced Virgo detectors. The search algorithm uses a hidden Markov model, where the transition probabilities allow the frequency to wander according to an unbiased random walk, while the J-statistic maximum-likelihood matched filter tracks the binary orbital phase. Three narrow subbands are searched for each target, centered on harmonics of the measured spin frequency. The search yields 16 candidates, consistent with a false alarm probability of …

Comparison Of Maximum-Likelihood Mapping Methods For Gravitational-Wave Backgrounds, Arianna I. Renzini, Joseph D. Romano, Carlo R. Contaldi, Neil Cornish

Physics and Astronomy Faculty Publications and Presentations

Detection of a stochastic background of gravitational waves is likely to occur in the next few years. Beyond searches for the isotropic component of a stochastic gravitational-wave background, there have been various mapping methods proposed to target anisotropic backgrounds. Some of these methods have been applied to data taken by the Laser Interferometer Gravitational-wave Observatory (LIGO) and Virgo. Specifically, these directional searches have focused on mapping the intensity of the signal on the sky via maximum-likelihood solutions. We compare this intensity mapping approach to a previously proposed, but never employed, amplitude-phase mapping method to understand whether this latter approach may …

Using A Stochastic Continuous-Time Markov Chain Model To Examine Alternative Timing And Duration Of The Covid-19 Lockdown In Kuwait: What Can Be Done Now?, Mustafa Al-Zoughool, Tamer Oraby, Harri Vainio, Janvier Gasana, Joseph C. Longenecker, Walid Al Ali, Mohammad Alseaidan, Susie Elsaadany, Michael G. Tyshenko

School of Mathematical and Statistical Sciences Faculty Publications and Presentations

Background

Kuwait had its first COVID-19 in late February, and until October 6, 2020 it recorded 108,268 cases and 632 deaths. Despite implementing one of the strictest control measures-including a three-week complete lockdown, there was no sign of a declining epidemic curve. The objective of the current analyses is to determine, hypothetically, the optimal timing and duration of a full lockdown in Kuwait that would result in controlling new infections and lead to a substantial reduction in case hospitalizations.

Methods

The analysis was conducted using a stochastic Continuous-Time Markov Chain (CTMC), eight state model that depicts the disease transmission and …

Optimal Measures For P-Frame Energies On Spheres, Dmitriy Bilyk, Alexey Glazyrin, Ryan Matzke, Josiah Park, Oleksandr Vlasiuk

School of Mathematical and Statistical Sciences Faculty Publications and Presentations

We provide new answers about the distribution of mass on spheres so as to minimize energies of pairwise interactions. We find optimal measures for the pp-frame energies, i.e., energies with the kernel given by the absolute value of the inner product raised to a positive power pp. Application of linear programming methods in the setting of projective spaces allows for describing the minimizing measures in full in several cases: we show optimality of tight designs and of the 600-cell for several ranges of pp in different dimensions. Our methods apply to a much broader class of potential functions, namely, those …

Individual Element Sensitivity For Stellar Evolutionary Isochrones, Guy Worthey, Xiang Shi, Tathagata Pal, Hyun-Chul Lee, Baitian Tang

Physics and Astronomy Faculty Publications and Presentations

Stellar evolution calculations with variable abundance ratios were used to gauge the effects on temperatures, luminosities, and lifetimes in various phases. The individual elements C, N, O, Mg, Si, and Fe were included. Most of the effect relevant to integrated light models is contained in the temperature variable, as opposed to the time-scale or luminosity. We derive a recipe for including abundance-sensitive temperature effects that is applicable to existing isochrone grids. The resultant enhanced isochrones are incorporated into composite stellar population models and compared with galaxy data from the Sloan Digital Sky Survey. A severe oxygen–age degeneracy is apparent, 2–3 …

Role Of Imine Isomerization In The Stereocontrol Of The Staudinger Reaction Between Ketenes And Imines, Fernando P. Cossío, Abel De Cózar, Miguel A. Sierra, Luis Casarrubios, Jaime G. Muntaner, Bimal K. Banik, Debasish Bandyopadhyay

Chemistry Faculty Publications and Presentations

Computational–experimental analysis has allowed determining that the stereochemistry of the Staudinger reaction between ketenes and imines is strongly associated with the nature of the imine, which affects the two steps of the reaction. The first step, namely the nucleophilic attack of the sp2-hybridized nitrogen atom of the imine on the sp-hybridized carbon atom of the ketene, is affected by the energetically accessible in situ isomerization patterns of the imine. The second step consists of a conrotatory electrocyclization of the zwitterionic intermediate formed in the previous step. This latter pericyclic step depends on the inward/outward torquoelectronic effects generated by the substituents …

Studying Spread Patterns Of Covid-19 Based On Spatiotemporal Data, Beiyu Lin, Xiaowei Jia, Zhiqian Chen

Computer Science Faculty Publications and Presentations

The current COVID-19 epidemic have transformed every aspect of our lives, especially our behavior and routines. These changes have been drastically impacting the economy in each region, such as local restaurants and transportation systems. With massive amounts of ambient data being collected everywhere, we now can develop innovative algorithms to have a much greater understanding of epidemic spread patterns of COVID-19 based on spatiotemporal data. The findings will open up the possibility to design adaptive planning or scheduling systems that will help preventing the spread of COVID-19 and other infectious diseases.

In this tutorial, we will review the trending state-of-theart …

Unique Assembly Verification In Two-Handed Self-Assembly, David Caballero, Timothy Gomez, Robert Schweller, Tim Wylie

Computer Science Faculty Publications and Presentations

One of the most fundamental and well-studied problems in Tile Self-Assembly is the Unique Assembly Verification (UAV) problem. This algorithmic problem asks whether a given tile system uniquely assembles a specific assembly. The complexity of this problem in the 2-Handed Assembly Model (2HAM) at a constant temperature is a long-standing open problem since the model was introduced. Previously, only membership in the class coNP was known and that the problem is in P if the temperature is one (τ=1). The problem is known to be hard for many generalizations of the model, such as allowing one step into the third …

Exceptional Point Generated Robust Asymmetric High-Order Harmonics, Hamidreza Ramezani, Amir Targholizadeh, Gui-Lei Zhu, Xin-You Lü, Cem Yuce

Physics and Astronomy Faculty Publications and Presentations

Using exceptional point dynamics in time and space modulated lattices we propose a new mechanism for generation of asymmetric robust higher harmonics. Specifically we design a metallic-silicon system with a complex optical potential spatiotemporally modulated along the length of the waveguide for this robust higher harmonic generation. In our system the dynamical equations associated with modal field amplitudes are described by a Jordan form Hamiltonian. This ultimately will allow for a unidirectional higher frequency generation which always has a maximum value for a specific length of the waveguide irrespective of the geometrical imperfections in the design of the waveguide. Furthermore, …

Saturating Relationship Between Phytoplankton Growth Rate And Nutrient Concentration Explained By Macromolecular Allocation, Jongsun Kim, Gabrielle Armin, Keisuke Inomura

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

Phytoplankton account for about a half of photosynthesis in the world, making them a key player in the ecological and biogeochemical systems. One of the key traits of phytoplankton is their growth rate because it indicates their productivity and affects their competitive capability. The saturating relationship between phytoplankton growth rate and environmental nutrient concentration has been widely observed yet the mechanisms behind the relationship remain elusive. Here we use a mechanistic model and metadata of phytoplankton to show that the saturating relationship between growth rate and nitrate concentration can be interpreted by intracellular macromolecular allocation. At low nitrate levels, the …