Physical Sciences and Mathematics Commons^™

Source Apportionment And Health Risk Assessment Of Nitrate In Foothill Aquifers Of Western Ghats, South India, Banajarani Panda, S. Chidambaram, Daniel D. Snow, Arindam Malakar, Dhiraj Kr Singh, L. Ramanathan

Nebraska Water Center: Faculty Publications

The present research reports the level of nitrate (NO₃^-), associated health risks and possible sources of contamination in groundwater from south India. Many samples (32%) are above or approaching the recommended level of NO₃^- for safe drinking water. The correlation analysis indicates different sources of NO₃^- contamination in different regions rather than a common origin. The isotopic measurements provide information about potential nitrogen sources contributing NO₃^- to the groundwater. Based on isotope analysis, the sources of NO₃^- in the groundwater of this region are likely to be from (a) …

Computational Solutions To Exosomal Microrna Biomarker Detection In Pancreatic Cancer, Thuy T. An

Department of Computer Science and Engineering: Dissertations, Theses, and Student Research

Pancreatic cancer is the fourth leading cause of cancer death in the United States and the 5-year survival rate is only 5% to 10%. There are only a few non-specific symptoms associated with the early-stage cancer, therefore most patients are diagnosed in a late stage. Due to the lack of effective treatments and the fact that the early stage has a 39% 5-year survival rate, the biggest hope to control this disease is early detection. Therefore, discovery of effective and reliable non-invasive biomarkers for early detection of pancreatic cancer has been a major topic. Very recently, exosomal microRNAs have become …

Semantically Meaningful Sentence Embeddings, Rojina Deuja

Department of Computer Science and Engineering: Dissertations, Theses, and Student Research

Text embedding is an approach used in Natural Language Processing (NLP) to represent words, phrases, sentences, and documents. It is the process of obtaining numeric representations of text to feed into machine learning models as vectors (arrays of numbers). One of the biggest challenges in text embedding is representing longer text segments like sentences. These representations should capture the meaning of the segment and the semantic relationship between its constituents. Such representations are known as semantically meaningful embeddings. In this thesis, we seek to improve upon the quality of sentence embeddings that capture semantic information.

The current state-of-the-art models are …

Risk-Based Machine Learning Approaches For Probabilistic Transient Stability, Umair Shahzad

Department of Electrical and Computer Engineering: Dissertations, Theses, and Student Research

Power systems are getting more complex than ever and are consequently operating close to their limit of stability. Moreover, with the increasing demand of renewable wind generation, and the requirement to maintain a secure power system, the importance of transient stability cannot be overestimated. Considering its significance in power system security, it is important to propose a different approach for enhancing the transient stability, considering uncertainties. Current deterministic industry practices of transient stability assessment ignore the probabilistic nature of variables (fault type, fault location, fault clearing time, etc.). These approaches typically provide a conservative criterion and can result in expensive …

Comparative Analysis Of Kmer Counting And Estimation Tools, Ankitha Vejandla

Department of Computer Science and Engineering: Dissertations, Theses, and Student Research

The rapid development of next-generation sequencing (NGS) technologies for determining the sequence of DNA has revolutionized genome research in recent years. De novo assemblers are the most commonly used tools to perform genome assembly. Most of the assemblers use de Bruijn graphs that break the sequenced reads into smaller sequences (sub-strings), called kmers, where k denotes the length of the sub-strings. The kmer counting and analysis of kmer frequency distribution are important in genome assembly. The main goal of this research is to provide a detailed analysis of the performance of different kmer counting and estimation tools that are currently …

Crest Or Trough? How Research Libraries Used Emerging Technologies To Survive The Pandemic, So Far, Scout Calvert

UNL Libraries: Faculty Publications

Introduction

In the first months of the COVID-19 pandemic, it was impossible to tell if we were at the crest of a wave of new transmissions, or a trough of a much larger wave, still yet to peak. As of this writing, as colleges and universities prepare for mostly in-person fall 2021 semesters, case counts in the United States are increasing again after a decline that coincided with easier access to the COVID vaccine. Plans for a return to campus made with confidence this spring may be in doubt, as we climb the curve of what is already the second …

Greenhouse Gas Emissions And Drought Projections For Nebraska, Adam Liska

Adam Liska Papers

This lecture will focus on three issues. The first is a presentation of data from the first greenhouse gas emissions inventory for the State of Nebraska, which will be published in the coming weeks. In 2016, emissions from beef cattle made up 23% of net state emissions, and coal for electricity made up 23.7% of net state emissions. The second issue to be addressed are the impacts of the 2012 drought on agriculture in Nebraska and the region. The drought of 2012 indicates that future droughts in the 21^st century in the region can be a dominant influence on …

High-Frequency And Below Bandgap Anisotropic Dielectric Constants In Α-(AlXGa1-X)2O3 (0≤X≤1), Matthew Hilfiker, Ufuk Kilic, Megan Stokey, Riena Jinno, Yongjin Cho, Huili Grace Xing, Debdeep Jena, Rafal Korlacki, Mathias Schubert

Department of Electrical and Computer Engineering: Faculty Publications

A Mueller matrix spectroscopic ellipsometry approach was used to investigate the anisotropic dielectric constants of corundum α-(Al_xGa_1-x)₂O₃ thin films in their below bandgap spectral regions. The sample set was epitaxially grown using plasma-assisted molecular beam epitaxy on m-plane sapphire. The spectroscopic ellipsometry measurements were performed at multiple azimuthal angles to resolve the uniaxial dielectric properties. A Cauchy dispersion model was applied, and high-frequency dielectric constants are determined for polarization perpendicular (ε_∞,⟂) and parallel (ε_∞,∥) to the thin film c-axis. The optical birefringence is negative throughout the …

Power-Over-Tether Unmanned Aerial System Leveraged For Trajectory Influenced Atmospheric Sensing, Daniel Rico

Department of Computer Science and Engineering: Dissertations, Theses, and Student Research

The use of unmanned aerial systems (UASs) in agriculture has risen in the past decade and is helping to modernize agriculture. UASs collect and elucidate data previously difficult to obtain and are used to help increase agricultural efficiency and production. Typical commercial off-the-shelf (COTS) UASs are limited by small payloads and short flight times. Such limits inhibit their ability to provide abundant data at multiple spatiotemporal scales. In this thesis, we describe the design and construction of the tethered aircraft unmanned system (TAUS), which is a novel power-over-tether UAS configured for long-term, high throughput atmospheric monitoring with an array of …

A Real-World, Hybrid Event Sequence Generation Framework For Android Apps, Jun Sun

Department of Computer Science and Engineering: Dissertations, Theses, and Student Research

Generating meaningful inputs for Android apps is still a challenging issue that needs more research. Past research efforts have shown that random test generation is still an effective means to exercise User-Interface (UI) events to achieve high code coverage. At the same time, heuristic search approaches can effectively reach specified code targets. Our investigation shows that these approaches alone are insufficient to generate inputs that can exercise specific code locations in complex Android applications.

This thesis introduces a hybrid approach that combines two different input generation techniques--heuristic search based on genetic algorithm and random instigation of UI events, to reach …

Using Contextual Bandits To Improve Traffic Performance In Edge Network, Aziza Al Zadjali

Department of Computer Science and Engineering: Dissertations, Theses, and Student Research

Edge computing network is a great candidate to reduce latency and enhance performance of the Internet. The flexibility afforded by Edge computing to handle data creates exciting range of possibilities. However, Edge servers have some limitations since Edge computing process and analyze partial sets of information. It is challenging to allocate computing and network resources rationally to satisfy the requirement of mobile devices under uncertain wireless network, and meet the constraints of datacenter servers too. To combat these issues, this dissertation proposes smart multi armed bandit algorithms that decide the appropriate connection setup for multiple network access technologies on the …

Aerial Flight Paths For Communication, Alisha Bevins

Department of Computer Science and Engineering: Dissertations, Theses, and Student Research

This body of work presents an iterative process of refinement to understand naive perception of communication using the motion of an unmanned aerial vehicle (UAV). This includes what people believe the UAV is trying to communicate, and how they expect to respond through physical action or emotional response. Previous work in this area sought to communicate without clear definitions of the states attempting to be conveyed. In an attempt to present more concrete states and better understand specific motion perception, this work goes through multiple iterations of state elicitation and label assignment. The lessons learned in this work will be …

Modernization Of Scienttific Mathematics Formula In Technology, Iwasan D. Kejawa Ed.D, Prof. Iwasan D. Kejawa Ed.D

Department of Mathematics: Faculty Publications

Abstract
Is it true that we solve problem using techniques in form of formula? Mathematical formulas can be derived through thinking of a problem or situation. Research has shown that we can create formulas by applying theoretical, technical, and applied knowledge. The knowledge derives from brainstorming and actual experience can be represented by formulas. It is intended that this research article is geared by an audience of average knowledge level of solving mathematics and scientific intricacies. This work details an introductory level of simple, at times complex problems in a mathematical epidermis and computability and solvability in a Computer Science. …

Biotransformation Of Doxycycline By Brevundimonas Naejangsanensis And Sphingobacterium Mizutaii Strains, Ting He, Jianguo Bao, Yifei Leng, Daniel D. Snow, Shuqiong Kong, Tong Wang, Xu Li

Nebraska Water Center: Faculty Publications

The fate of doxycycline (DC), a second generation tetracycline antibiotic, in the environment has drawn increasing attention in recent years due to its wide usage. Little is known about the biodegradability of DC in the environment. The objective of this study was to characterize the biotransformation of DC by pure bacterial strains with respect to reaction kinetics under different environmental conditions and biotransformation products. Two bacterial strains, Brevundimonas naejangsanensis DD1 and Sphingobacterium mizutaii DD2, were isolated from chicken litter and characterized for their biotransformation capability of DC. Results show both strains rely on cometabolism to biotransform DC with tryptone as …

Optical Phonon Modes, Static And High-Frequency Dielectric Constants, And Effective Electron Mass Parameter In Cubic In2O3, Megan Stokey, Rafal Korlacki, Sean Knight, Alexander Ruder, Matthew J. Hilfiker, Zbigniew Galazka, Klaus Irmscher, Yuxuan Zhang, Hongping Zhao, Vanya Darakchieva, Mathias Schubert

Department of Electrical and Computer Engineering: Faculty Publications

A complete set of all optical phonon modes predicted by symmetry for bixbyite structure indium oxide is reported here from a combination of far-infrared and infrared spectroscopic ellipsometry, as well as first principles calculations. Dielectric function spectra measured on high quality, marginally electrically conductive melt grown single bulk crystals are obtained on a wavelength-by-wavelength (also known as point-by-point) basis and by numerical reduction of a subtle free charge carrier Drude model contribution. A four-parameter semi-quantum model is applied to determine all 16 pairs of infrared-active transverse and longitudinal optical phonon modes, including the high-frequency dielectric constant, ε_∞=4.05±0.05. The …

Modeling Vadose Zone Hydrology: Lecture Notes, Derek M. Heeren, Dean Eisenhauer

Open Educational Resources for Engineering

Modeling Vadose Zone Hydrology is a graduate-level course offered biennially in the Department of Biological Systems Engineering. Topics included hydraulic properties of porous media, application of Darcy's Law in variably saturated media, hydrologic and transport processes in the vadose zone, and solution of steady and unsteady flow problems using numerical techniques. A graphical approach for characterizing vertical one-dimensional problems with energy head profiles was emphasized. Common one-dimensional flow and transport problems were solved analytically. The course was taught using a combination of lecture notes and PowerPoint presentations. The lecture notes from 2021, captured using the Microsoft Whiteboard app with a …

Novel And Fast Peridynamic Models For Material Degradation And Failure, Siavash Jafarzadeh

Department of Mechanical and Materials Engineering: Dissertations, Theses, and Student Research

Fracture is one of the main mechanisms of structural failure. Corroded surfaces with chemically-induced damage are, notably, potential sites for crack initiation and propagation in metals, which can lead to catastrophic failure of structures. Despite some progress in simulating fracture and damage using classical models, realistic prediction of complex damage progression and failure has been out of reach for many decades. Peridynamics (PD), a nonlocal theory introduced in 2000, opened up new avenues in modeling material degradation and failure. Existing numerical methods used to discretize PD equations, however, are quite expensive as the PD nonlocal interactions make them unaffordable for …

Using An Integrative Machine Learning Approach To Study Microrna Regulation Networks In Pancreatic Cancer Progression, Roland Madadjim

Department of Computer Science and Engineering: Dissertations, Theses, and Student Research

With advances in genomic discovery tools, recent biomedical research has produced a massive amount of genomic data on post-transcriptional regulations related to various transcript factors, microRNAs, lncRNAs, epigenetic modifications, and genetic variations. In this direction, the field of gene regulation network inference is created and aims to understand the interactome regulations between these molecules (e.g., gene-gene, miRNA-gene) that take place to build models able to capture behavioral changes in biological systems. A question of interest arises in integrating such molecules to build a network while treating each specie in its uniqueness. Given the dynamic changes of interactome in chaotic systems …

Real-Time Monitoring Of Fdm 3d Printer For Fault Detection Using Machine Learning: A Bibliometric Study, Vaibhav Kisan Kadam, Satish Kumar, Arunkumar Bongale

Library Philosophy and Practice (e-journal)

Additive Manufacturing has wide application range including healthcare, Fashion, Manufacturing, Prototypes, Tooling etc. AM techniques are subjected to various defects that may be printing defects or anomalies in machine. There is gap between current AM techniques and smart manufacturing since current AM lacks in build sensors necessary for process monitoring and fault detection. Both of these issues can be solved by incorporating real-time monitoring into AM. So the study is carried out to identify recent work done in AM to improve current system. For this bibliometric study Scopus database is used, study is kept limited to year 2010-2021 and English …

Voltage-Controlled Magnetic Anisotropy In Antiferromagnetic Mgo-Capped Mnpt Films, P. H. Chang, Wuzhang Fang, T. Ozaki, Kirill Belashchenko

Kirill Belashchenko Publications

The magnetic anisotropy in MgO-capped MnPt films and its voltage control are studied using first-principles calculations. Sharp variation of the magnetic anisotropy with film thickness, especially in the Pt-terminated film, suggests that it may be widely tuned by adjusting the film thickness. In thick films the linear voltage control coefficient is as large as 1.5 and -0.6 pJ/Vm for Pt-terminated and Mn-terminated interfaces, respectively. The combination of a widely tunable magnetic anisotropy energy and a large voltage-control coefficient suggest that MgO-capped MnPt films can serve as a versatile platform for magnetic memory and antiferromagnonic applications.

Teachability And Interpretability In Reinforcement Learning, Jeevan Rajagopal

Department of Computer Science and Engineering: Dissertations, Theses, and Student Research

There have been many recent advancements in the field of reinforcement learning, starting from the Deep Q Network playing various Atari 2600 games all the way to Google Deempind's Alphastar playing competitively in the game StarCraft. However, as the field challenges more complex environments, the current methods of training models and understanding their decision making become less effective. Currently, the problem is partially dealt with by simply adding more resources, but the need for a better solution remains.

This thesis proposes a reinforcement learning framework where a teacher or entity with domain knowledge of the task to complete can assist …

“The Revolution Will Not Be Supervised": An Investigation Of The Efficacy And Reasoning Process Of Self-Supervised Representations, Atharva Tendle

Department of Computer Science and Engineering: Dissertations, Theses, and Student Research

Transfer learning technique enables training Deep Learning (DL) models in a data-efficient way for solving computer vision tasks. It involves pretraining a DL model to learn representations from a large and general-purpose source dataset, then fine-tuning the model using the task-specific target dataset. The dominant supervised learning (SL) approach for pretraining representations suffers from some limitations that include expensive labeling and poor generalizability. Recent advancements in the self-supervised learning (SSL) approach made it possible to learn effective representations from unlabeled data. The performance of the fine-tuned DL models based on pretrained SSL representations is on par with the state-of-the-art pretrained …

Challenges And Opportunities In Precision Irrigation Decision-Support Systems For Center Pivots, Jingwen Zhang, Kaiyu Guan, Bin Peng, Chongya Jiang, Wang Zhou, Yi Yang, Ming Pan, Trenton Franz, Derek M. Heeren, Daran R. Rudnick, Olufemi P. Abimbola, Hyungsuk Kimm, Kelly Caylor, Stephen Good, Madhu Khanna, John Gates, Yaping Cai

Biological Systems Engineering: Papers and Publications

Irrigation is critical to sustain agricultural productivity in dry or semi-dry environments, and center pivots, due to their versatility and ruggedness, are the most widely used irrigation systems. To effectively use center pivot irrigation systems, producers require tools to support their decision-making on when and how much water to irrigate. However, currently producers make these decisions primarily based on experience and/or limited information of weather. Ineffective use of irrigation systems can lead to overuse of water resources, compromise crop productivity, and directly reduce producers’ economic return as well as bring negative impacts on environmental sustainability. In this paper, we surveyed …

Removal Of Carbamazepine Onto Modified Zeolitic Tuff In Different Water Matrices: Batch And Continuous Flow Experiments, Othman A. Al-Mashaqbeh, Diya A. Alsafadi, Layal Z. Alsalhi, Shannon L. Bartelt-Hunt, Daniel D. Snow

Nebraska Water Center: Faculty Publications

Carbamazepine (CBZ) is the most frequently detected pharmaceutical residues in aquatic environments effluent by wastewater treatment plants. Batch and column experiments were conducted to evaluate the removal of CBZ from ultra-pure water and wastewater treatment plant (WWTP) effluent using raw zeolitic tuff (RZT) and surfactant modified zeolite (SMZ). Point zero net charge (pHpzc), X-ray diffraction (XRD), X-ray fluorescence (XRF), and Fourier Transform Infrared (FTIR) were investigated for adsorbents to evaluate the physiochemical changes resulted from the modification process using Hexadecyltrimethylammonium bromide (HDTMA-Br). XRD and FTIR showed that the surfactant modification of RZT has created an amorphous surface with new alkyl …

Bibliometric Analysis Of Named Entity Recognition For Chemoinformatics And Biomedical Information Extraction Of Ovarian Cancer, Vijayshri Khedkar, Charlotte Fernandes, Devshi Desai, Mansi R, Gurunath Chavan Dr, Sonali Tidke Dr., M. Karthikeyan Dr.

Library Philosophy and Practice (e-journal)

With the massive amount of data that has been generated in the form of unstructured text documents, Biomedical Named Entity Recognition (BioNER) is becoming increasingly important in the field of biomedical research. Since currently there does not exist any automatic archiving of the obtained results, a lot of this information remains hidden in the textual details and is not easily accessible for further analysis. Hence, text mining methods and natural language processing techniques are used for the extraction of information from such publications.Named entity recognition, is a subtask that comes under information extraction that focuses on finding and categorizing specific …

Zinc Gallate Spinel Dielectric Function, Band-To-Band Transitions, And Γ-Point Effective Mass Parameters, Matthew J. Hilfiker, Megan Stokey, Rafal Korlacki, Ufuk Kilic, Zbigniew Galazka, Klaus Irmscher, Stefan Zollner, Mathias Schubert

Department of Electrical and Computer Engineering: Faculty Publications

We determine the dielectric function of the emerging ultrawide bandgap semiconductor ZnGa₂O₄ from the near-infrared (0.75 eV) into the vacuum ultraviolet (8.5 eV) spectral regions using spectroscopic ellipsometry on high quality single crystal substrates. We perform density functional theory calculations and discuss the band structure and the Brillouin zone Γ-point band-to-band transition energies, their transition matrix elements, and effective band mass parameters. We find an isotropic effective mass parameter (0.24m_e) at the bottom of the Γ-point conduction band, which equals the lowest valence band effective mass parameter at the top of the highly anisotropic …

Exploring The Efficiency Of Self-Organizing Software Teams With Game Theory, Clay Stevens, Jared Soundy, Hau Chan

CSE Conference and Workshop Papers

Over the last two decades, software development has moved away from centralized, plan-based management toward agile methodologies such as Scrum. Agile methodologies are founded on a shared set of core principles, including self-organizing software development teams. Such teams are promoted as a way to increase both developer productivity and team morale, which is echoed by academic research. However, recent works on agile neglect to consider strategic behavior among developers, particularly during task assignment–one of the primary functions of a self-organizing team. This paper argues that self-organizing software teams could be readily modeled using game theory, providing insight into how agile …

Unsupervised Data Mining Technique For Clustering Library In Indonesia, Robbi Rahim, Joseph Teguh Santoso, Sri Jumini, Gita Widi Bhawika, Daniel Susilo, Danny Wibowo

Library Philosophy and Practice (e-journal)

Organizing school libraries not only keeps library materials, but helps students and teachers in completing tasks in the teaching process so that national development goals are in order to improve community welfare by producing quality and competitive human resources. The purpose of this study is to analyze the Unsupervised Learning technique in conducting cluster mapping of the number of libraries at education levels in Indonesia. The data source was obtained from the Ministry of Education and Culture which was processed by the Central Statistics Agency (abbreviated as BPS) with url: bps.go.id/. The data consisted of 34 records where the attribute …

Modeling The Release And Spreading Of Permanganate From Aerated Slow-Release Oxidants In A Laboratory Flow Tank, Ann Kambhu, Yusong Li, Troy E. Gilmore, Steve D. Comfort

School of Natural Resources: Faculty Publications

Aerated, slow-release oxidants are a relatively new technology for treating contaminated aquifers. A critical need for advancing this technology is developing a reliable method for predicting the radius of influence (ROI) around each drive point. In this work, we report a series of laboratory flow tank experiments and numerical modeling efforts designed to predict the release and spreading of permanganate from aerated oxidant candles (oxidant-wax composites). To mimic the design of the oxidant delivery system used in the field, a double screen was used in a series of flow tank experiments where the oxidant was placed inside the inner screen …

Plasmonic Waveguides To Enhance Quantum Electrodynamic Phenomena At The Nanoscale, Ying Li, Christos Argyropoulos

Department of Electrical and Computer Engineering: Faculty Publications

The emerging field of plasmonics can lead to enhanced light-matter interactions at extremely nanoscale regions. Plasmonic (metallic) devices promise to efficiently control both classical and quantum properties of light. Plasmonic waveguides are usually used to excite confined electromagnetic modes at the nanoscale that can strongly interact with matter. The analysis of these nanowaveguides exhibits similarities with their low frequency microwave counterparts. In this article, we review ways to study plasmonic nanostructures coupled to quantum optical emitters from a classical electromagnetic perspective. These quantum emitters are mainly used to generate single-photon quantum light that can be employed as a quantum bit …