Digital Commons Network^™

Infants' Facial Emotion Recognition, Umme Fatema

UNLV Theses, Dissertations, Professional Papers, and Capstones

Facial Emotion Recognition (FER) has become a popular computer vision topic and attracted a lot of researchers. However, these researches mostly focus on adult facial emotion. Infants’ facial structure and expression of emotions differ from adults’. That is why our target is to create a model that particularly focuses on infants’ facial emotions. In this work, we classify three types of emotions: positive, negative, and neutral. Two datasets are used in this work. One is an image-based dataset named ‘The City’ that consists of 154 images of infants aged 0-12 months. Another is the Rebel Dataset from the Department of …

Healthy Aging In Place: An Integrated Smart Home Using Alexa-Compatible Technology, Tyler Kryst

UNLV Theses, Dissertations, Professional Papers, and Capstones

The purpose of this research was to address current healthcare concerns among the aging population. Around the globe, the average life expectancy is projected to continue increasing resulting in a higher prevalence of age-related disease. With the ever-increasing capabilities of modern technology, it is necessary to apply this technology to increase the health and safety of older adults. This work had three objectives. The first objective was the establishment of an integrated smart home aimed at creating a healthy aging-in-place environment through the use of Alexa. The second objective was the development and integration of a completely custom health device …

School Climate, Teacher Self-Efficacy, And Teaching Practices: Evidence From Talis 2018, Chengcheng Li

UNLV Theses, Dissertations, Professional Papers, and Capstones

Since the enactment of Every Student Succeeds Act (ESSA) in 2016, K-12 schools in the U.S. have responded to the challenge with various instructional reform initiatives. School climate, teaching practices, and teacher self-efficacy are important aspects of research as they affect students’ learning. The purpose of this study was twofold: first, to evaluate the goodness of fit of the three hypothesized mediation models with the data from the Teaching and Learning International Survey (TALIS) using Structural Equation Modeling (SEM); and second, to determine the interrelations between teacher self-efficacy, school climate, and teaching practices. To address the research questions and hypotheses, …

Food Insecurity And Risky Sexual Behaviors Among College Students, Bertille Octavie Mavegam Tango Assoumou M

UNLV Theses, Dissertations, Professional Papers, and Capstones

Food insecurity and sexually transmitted infections (STIs) are growing public health problems in the United States. Young people in general, and particularly college students, exhibit high prevalence of food insecurity, STIs, and risky sexual behaviors (RSB). Food insecurity and STIs among college students can have short- and long-term impacts on their academic success and their lives. Several studies have reported an association between food insecurity and some risky sexual behaviors among specific populations including HIV-infected people and homeless people. However, little is known about the relationship between food insecurity and RSB among college students. Given the high prevalence of food …

Estimation Of Spatial Change In Cropland Area And Evaluation Of Irrigation Performance In Imperial Valley Using Remotely Sensed Data, Usha Poudel

UNLV Theses, Dissertations, Professional Papers, and Capstones

The Imperial Valley (IV) in the US is an extensively irrigated agricultural region, which includes multiple crops changing on an annual and semiannual basis. The valley is facing grave concerns about water management due to its semi-arid environment, water intensive crops, and limited water supply. A simple, inexpensive, and repeatable method to detect changes in cropping patterns may assist irrigation managers to understand crop diversification and associated consumptive use. In addition, a spatial assessment of existing water irrigation system performance and productivity is crucial to benchmark and improve current water management strategies. This thesis estimates the spatial pattern of change …

Who Participates In The Skilled Technical Workforce After College And What Are Their Educational Pathways?, Xianglei Chen

Journal of Research in Technical Careers

The skilled technical workforce (STW) comprises workers in occupations that require significant science, technology, engineering, or mathematics (STEM) skills but not a bachelor’s degree for entry. The United States had over 17 million STW workers in 2017, and is expected to be short about 3.4 million workers who are qualified for the available STW positions by 2022. Despite the important contribution of the STW to the U.S. economy, the policy discourse on the STEM workforce has largely focused on workers with bachelor’s or graduate degrees, overlooking those without a 4-year degree. Consequently, knowledge about the STW is limited. This paper …

The Value Of Education Between Two African American Male Populations In A Rural Southern Community, Quentin R. Tyler, Stacy K. Vincent, Tiffany C. Monroe

Journal of Research in Technical Careers

This study identified perceptions of education by low performing and college track African American males in a rural town in Southern Kentucky. Through the lens of Critical Race Theory and Symbolic Interactionism, the researchers explored how 16 young men value a secondary and postsecondary education. Selected by their administrator at two high schools, the males were identified as college track or low performing. The findings revealed that both groups identify racial relations as a barrier to educational achievement; however, college track males believed education would assist in overcoming racial divides. Additional findings highlight a difference in perception based upon the …

Identifying Essential Fisheries Competencies To Link To School Curriculum: Supporting Nez Perce Students’ Stem Identity, Raymond A. Dixon, Karla Eitel, Teresa Cohn, Marcie Carter, Kay Seven

Journal of Research in Technical Careers

This study examined the process to identify required competencies for an entry-level position in the Nez Perce Tribe Department of Fisheries Resource Management located in the Pacific Northwest. The overall goal was to provide content for a pedagogical framework to support Nez Perce students in the development of their STEM identity and to consider careers in natural resources and fisheries. The DACUM process was used to analyze the job, Fisheries Technician. The process involved a focus group of six expert workers in the Department of Fisheries Resource Management and was led by a facilitator. The experts identified 48 competencies categorized …

Molybdenite Re–Os, Titanite And Garnet U–Pb Dating Of The Magushan Skarn Cu–Mo Deposit, Xuancheng District, Middle–Lower Yangtze River Metallogenic Belt, Yue Li, Feng Yuan, Simon M. Jowitt, Fangyue Wang, Xiangling Li, Yufeng Deng, Yunyue Wang, Taofa Zhou

Geoscience Faculty Research

© 2020 Elsevier B.V. The Magushan skarn Cu–Mo deposit is a representative example of the skarn mineralization occurring within the Xuancheng ore district of the Middle–Lower Yangtze River Metallogenic Belt of eastern China. The precise age of an ore deposit is important for understanding the timing of mineralization relative to other geological events in a region and to fully place the formation of a mineral deposit within the geological context of other processes that occur within the study area. Here, we present new molybdenite Re–Os and titanite and andradite garnet U–Pb ages for the Magushan deposit and use these data …

Extreme Event Reconstructions For The Upper Fraser River Basin, British Columbia, Canada, Inga K. Homfeld

UNLV Theses, Dissertations, Professional Papers, and Capstones

Spring freshets and summer droughts have recently worsened in the Fraser River Basin, British Columbia, Canada, with significant impacts to the keystone Pacific salmon populations, the food and economic sovereignty of over eighty First Nations, and the western Canadian economy. These extreme events present a potential risk since, unlike many large and less hydroclimatically-complex and/or empounded watersheds, the Fraser River Basin is susceptible to a combination of unregulated spring freshet and summer drought events even within the same year. A major limitation for understanding past and future extreme event risk in the Fraser River Basin is that observational streamflow datasets …

Effect Of Boundary Approximation On Visibility, Samridhi Jha

UNLV Theses, Dissertations, Professional Papers, and Capstones

The problem of simplifying a complex shape with simpler ones is an important research area in computer science and engineering. In this thesis, we investigate the effect on the visibility properties of polygons when their boundaries are approximated to make them simpler. We present two algorithms for approximating a restricted class of polygons called 1.5 D terrain. We also present experimental investigations on the performance of reviewed and proposed approximation algorithms.

A Fusion Of Remotely Sensed Data To Map The Impervious Surfaces Of Growing Cities Of Punjab, Pakistan, Binita Shrestha

UNLV Theses, Dissertations, Professional Papers, and Capstones

Urban population is expected to exceed 70% of the world’s total by the middle of the 21st century. Thus, growth in number as well as the sizes of the cities are certain in the near future. The urbanization rates will be much higher in the developing countries than the developed. Such phenomena are accompanied by conversion of land cover from its natural use to built up environment to accommodation growing population. Built up surfaces include road networks, buildings, parking lots and pathways. They are permanently impervious and hydrologically active surfaces. Large volume and discharges of runoff characterize impervious surfaces with …

Experimental Constraint On Axionlike Particles Over Seven Orders Of Magnitude In Mass, Tanya S. Roussy, Daniel A. Palken, William B. Cairncross, Benjamin M. Brubaker, Daniel N. Gresh, Matt Grau, Kevin C. Cossel, Kia Boon Ng, Yuval Shagam, Yan Zhou, Victor V. Flambaum, Konrad W. Lehnert, Jun Ye, Eric A. Cornell

Physics & Astronomy Faculty Research

We use our recent electric dipole moment (EDM) measurement data to constrain the possibility that the HfF+ EDM oscillates in time due to interactions with candidate dark matter axionlike particles (ALPs). We employ a Bayesian analysis method which accounts for both the look-elsewhere effect and the uncertainties associated with stochastic density fluctuations in the ALP field. We find no evidence of an oscillating EDM over a range spanning from 27 nHz to 400 mHz, and we use this result to constrain the ALP-gluon coupling over the mass range 10-22-10-15 eV. This is the first laboratory constraint on the ALP-gluon coupling …

Increasing Investment In Stem Education For Females: Policy Considerations, Becky Harris, Andrea Dassopoulos, Daniel Sahl, Anna Starostina

UNLV Gaming Research & Review Journal

During this difficult economic time, as policy makers decide how to use their limited resources to help prepare the rising generation for the demands of an ever-changing workforce, aligning K-12 educational priorities with higher education and economic development can help maximize public dollar investments in STEM education, particularly when females are given access to STEM and STEM-related education and programs. Smart public policy initiatives can help increase the representation of women in the technology, research and development, and innovation departments.

The purpose of this article is to provide policy recommendations that could help increase gender diversity and participation in STEM …

On The Role Of Resonances In Polluting White Dwarfs By Asteroids, Jeremy L. Smallwood, Rebecca G. Martin, Mario Livio, Dimitri Veras

Physics & Astronomy Faculty Research

Pollution of white dwarf atmospheres may be caused by asteroids that originate from the locations of secular and mean-motion resonances in planetary systems. Asteroids in these locations experience increased eccentricity, leading to tidal disruption by the white dwarf. We examine how the ν6 secular resonance shifts outwards into a previously stable region of the asteroid belt, as the star evolves to a white dwarf. Analytic secular models require a planet to be engulfed in order to shift the resonance. We show with numerical simulations that as a planet gets engulfed by the evolving star, the secular resonance shifts and the …

Equation Of State For Natural Almandine, Spessartine, Pyrope Garnet: Implications For Quartz-In-Garnet Elastic Geobarometry, Suzanne R. Mulligan, Elissaios Stavrou, Stella Chariton, Oliver Tschauner, Ashkan Salamat, Michael Wells, Alexander G. Smith, Thomas D. Hoisch, Vitali Prakapenka

Geoscience Faculty Research

The equation of state (EoS) of a natural almandine74spessartine13pyrope10grossular3 garnet of a typical composition found in metamorphic rocks in Earth’s crust was obtained using single crystal synchrotron X-ray diffraction under isothermal room temperature compression. A third-order Birch-Murnaghan EoS was fitted to P-V data and the results are compared with published EoS for iron, manganese, magnesium, and calcium garnet compositional end-members. This comparison reveals that ideal solid solution mixing can reproduce the EoS for this intermediate composition of garnet. Additionally, this new EoS was used to calculate geobarometry on a garnet sample from the same rock, which was collected from the …

Manganese Oxides In Martian Meteorites Northwest Africa (Nwa) 7034 And 7533, Yang Liu, Woodward W. Fischer, Chi Ma, John R. Beckett, Oliver Tschauner, Yunbin Guan, Usha F. Lingappa, Samuel M. Webb, Vitali B. Prakapenka, Nina L. Lanza, Carl B. Agee

Geoscience Faculty Research

We report the discovery of indigenous Mn-oxides in Martian regolith breccias Northwest Africa (NWA) 7034 and 7533. These Mn-oxides occur in Mn-rich regions as nanocrystals mixed with silicates, FeOOH, and possible phosphates. The Mn-rich regions contain up to 34 wt% Mn and typically display large chemical gradients on the scale of 10–20 μm. The Martian origin of Mn-oxides was established by the presence of Mn-rich glass (4.8–5.6 wt% Mn) in the fusion crust that crosscuts a Mn-oxides-bearing monzonite clast and by the absence of Mn-oxides on the environmentally exposed surfaces (exterior and fractures) of the meteorites. Manganese K-edge X-ray absorption …

A Multiproxy Database Of Western North American Holocene Paleoclimate Records, Cody C. Routson, Darrell S. Kaufman, Nicholas P. Mckay, Michael P. Erb, Stéphanie H. Arcusa, Kendrick J. Brown, Matthew E. Kirby, Jeremiah P. Marsicek, R. Scott Anderson, Gonzalo Jiménez-Moreno, Jessica R. Rodysill, Matthew S. Lachniet, Sherilyn C. Fritz, Joseph R. Bennett, Michelle F. Goman, Sarah E. Metcalfe, Jennifer M. Galloway, Gerrit Schoups, David B. Wahl, Jesse L. Morris, Francisca Staines-Urías, Andria Dawson, Bryan N. Shuman, Daniel G. Gavin, Jeffrey S. Munroe, Brian F. Cumming

Geoscience Faculty Research

Holocene climate reconstructions are useful for understanding the diverse features and spatial heterogeneity of past and future climate change. Here we present a database of western North American Holocene paleoclimate records. The database gathers paleoclimate time series from 184 terrestrial and marine sites, including 381 individual proxy records. The records span at least 4000 of the last 12 000 years (median duration of 10 725 years) and have been screened for resolution, chronologic control, and climate sensitivity. Records were included that reflect temperature, hydroclimate, or circulation features. The database is shared in the machine readable Linked Paleo Data (LiPD) format …

2022 Graduate Program Rankings, Unlv & Unr, Madison Frazee-Bench, Marie A. Falcone, Caitlin J. Saladino, William E. Brown Jr.

Higher Education

This Fact Sheet presents the 2022 U.S. News and World Report Graduate program rankings for the University of Nevada, Las Vegas (UNLV) and the University of Nevada, Reno (UNR). The rankings for 2022 are important when taking into consideration that both UNLV and UNR reached Carnegie R1 status in 2018. This status marks their place in the top 130 research universities in the country.

Modeling Covid-19 Infection Rates Using Sir And Arima Models, Janelle Domantay, Ilya Pivavaruk, Victor Taksheyev

Undergraduate Research Symposium Posters

With the onset of the COVID-19 pandemic, it has become of increasing interest to both monitor and predict the growth of its infection rates. In order to analyze the accuracy of epidemiological prediction, we consider two different models for prediction, the Susceptible Infected and Removed (SIR), and Autoregressive Integrated Moving Average (ARIMA) models. Using a dataset of Clark County COVID-19 infections, we create various ARIMA and SIR models that attempt to predict the progression of COVID-19 infections whilst comparing these predictions to the dataset. We observed that the ARIMA model performed more accurately overall, having a much lower Root Mean …

Increasing Analysis Efficiency Through Automation Of Inductively Coupled Plasma Mass Spectrometry (Icp-Ms) Data Reduction Process Using Python, Grace Abigail Martin

Undergraduate Research Symposium Posters

The Inductively Coupled Plasma Mass Spectrometry (ICP-MS) provides elemental analysis through ionization of samples. Numerous geochemistry laboratories utilize the ICP-MS and has become a community standard. The ICP-MS data reduction process is time intensive and involves correction for blank contribution and sensitivity drift during measurement, as well as construction of standard calibration lines based on measurements of standard solutions. We look to decrease turnaround time and increase efficiency through automation of the data reduction process using Python. The ICP-MS data reduction process was 3 hours or more, in our observations. Python packages such as Openpyxl and Pandas, allow us to …

Girls In Stem Day: From Space To Dna, An Analysis Of Middle School Girls' Interests In Stem Fields, Emily Carter

Undergraduate Research Symposium Podium Presentations

Research specifically targeted at youth participation in STEM highlights the importance of community engagements outside of school to bolster interest in STEM. We ask the research questions: (1) How do girls who engage with a day-long STEM event at UNLV perceive hands-on science activities? (2) How did girls’ enjoyment of science activities shift their interest in science topics? The purpose of this study is to identify factors that influence middle school girls’ interests in STEM fields through a day-long STEM event. This research was conducted at the University of Nevada, Las Vegas (UNLV) in 2020 called Girls in STEM Day …

Spike Nozzle Design For Use In Nanosat Orbital Maneuvering, Drew Nemeth

Undergraduate Research Symposium Podium Presentations

Annular spike nozzle engines have long been the holy grail of rocket engine design, promising superior performance in a smaller footprint when compared to conventional bell nozzles. However, flaws inherent to the design of spike nozzles have prevented widespread adoption and testing. As a result, research on potential applications has been quite sparse. This project aims to further spike nozzle research by investigating rarely tested materials that literature suggests have potential for use in a spike nozzle design. The goal of the overall research project is to examine 3D printed polycarbonate component longevity under conditions representative of a small satellite …

Investigating The Varying Behaviors Of Magnesium, Tin, And Lead Oxalate Under High-Pressure, Kevin Ayala Pineda

Undergraduate Research Symposium Posters

Recent developments in the field of useful hard x-ray induced chemistry synthesized a novel strontium-based CO derived material under extreme conditions. In hopes of synthesizing this material in larger quantities and in less expensive costs, we report three high-pressure Diamond Anvil Cell investigations on Tin Oxalate (SnC2O4), Magnesium Oxalate (MgC2O4), and Lead Oxalate (PbC2O4) subjected to extreme conditions without the use of hard x-rays. MgC2O4 were acquired up to 25 GPa, with a possible phase transition at 2.4 Gpa. SnC2O4 was pressurized up to 31 GPa inducing irreversible changes in both the Raman spectra and its qualitative properties. Three phase …

Overcoming The Overgeneration Of Renewables, Joshua Kaze, Ryan Barnard

Undergraduate Research Symposium Posters

Many states are addressing the issues of climate change, by changing how they produce their energy. The effects of these policies are causing many renewable sources to be underutilized. This paper analyzes how the diversification of energy generation is leading to inefficiencies in the California energy market and the western US market as a whole. The change in curtailment of non-dispatchable renewables is positively correlated with the growth of renewables. Summary statistics and regression analysis show that an increasing portion of renewables is being wasted as the quantity of renewables is increasing. The Renewable Portfolio Standards (RPS) that California introduced …

Toward A Quantum Neural Network: Proposing The Qaoa Algorithm To Replace A Feed Forward Neural Network, Erick Serrano

Undergraduate Research Symposium Posters

With a surge in popularity of machine learning as a whole, many researchers have sought optimization methods to reduce the complexity of neural networks; however, only recent attempts have been made to optimize neural networks via quantum computing methods. In this paper, we describe the training process of a feed forward neural network (FFNN) and the time complexity of the training process. We highlight the inefficiencies of the FFNN training process, particularly when implemented with gradient descent, and introduce a call to action for optimization of a FFNN. Afterward, we discuss the strides made in quantum computing to improve the …

Gambling Researchers’ Use And Views Of Open Science Principles And Practices: A Brief Report, Debi A. Laplante, Eric R. Louderback, Brett Abarbanel

International Gaming Institute Faculty Research

Scientists across disciplines have begun to implement ‘open science’ principles and practices, which are designed to enhance the quality, transparency, and replicability of scientific research. Yet, studies examining the use of open science practices in social science fields such as psychology and economics show that awareness and use of such practices often is low. In gambling studies research, no studies to date have empirically investigated knowledge of and use of open science practices. In the present study, we collected survey data about awareness and use of open science practices from 86 gambling studies research stakeholders who had attended a major …

Maximum Temperatures In Evolving Protoplanetary Discs And Composition Of Planetary Building Blocks, Min Li, Shichun Huang, Zhaohuan Zhu, Michael I. Petaev, Jason H. Steffen

Geoscience Faculty Research

The maximum temperature and radial temperature profile in a protoplanetary disc are important for the condensation of different elements in the disc. We simulate the evolution of a set of protoplanetary discs from the collapse of their progenitor molecular cloud cores as well as the dust decoupling within the discs as they evolve. We show how the initial properties of the cloud cores affect the thermal history of the protoplanetary discs using a simple viscous disc model. Our results show that the maximum mid-plane temperature in the disc occurs within 0.5 au. It increases with the initial cloud temperature and …

Pressure- And Temperature-Dependent Inelastic Neutron Scattering Study Of The Phase Transition And Phonon Lattice Dynamics In Para-Terphenyl, Qingan Cai, Michael Mcintire, Luke L. Daemen, Chen Li, Eric Chronister

Chemistry and Biochemistry Faculty Research

Inelastic neutron scattering has been performed on para-terphenyl at temperatures from 10 to 200 K and under pressures from the ambient pressure to 1.51 kbar. The temperature dependence of phonons, especially low-frequency librational bands, indicates strong anharmonic phonon dynamics. The pressure- and temperature-dependence of the phonon modes suggest a lack of phase transition in the region of 0-1.51 kbar and 10-30 K. Additionally, the overall lattice dynamics remains similar up to 200 K under the ambient pressure. The results suggest that the boundary between the ordered triclinic phase and the third solid phase, reported at lower temperatures and higher pressures, …

Steep Sulfur Gradient In Cztsse Solar Cells By H2s-Assisted Rapid Surface Sulfurization, Teoman Taskesen, Devendra Pareek, Dirk Hauschild, Alan Haertel, Lothar Weinhardt, Wanli Yang, Timo Pfeiffelmann, David Nowak, Clemens Heske, Levent Gütay

Chemistry and Biochemistry Faculty Research

Sulfur/selenium grading is a widely used optimization strategy in kesterite thin-film solar cells to obtain a bandgap-graded absorber material and to optimize optical and electrical properties of the solar-cell device. In this work, we present a novel approach to introduce a [S]/([S] + [Se]) grading for Cu ZnSn(S,Se) solar cells. In contrast to commonly used methods with slow process dynamics, the presented approach aims to create a fast sulfurization reaction on the surface of pure selenide kesterite absorbers by using highly reactive H S gas and high sulfurization temperatures in a rapid flash-type process. With a combination of X-ray photoelectron …