Physical Sciences and Mathematics Commons^™

Fast And Memory-Efficient Tfidf Calculation For Text Analysis Of Large Datasets, Samah Senbel

School of Computer Science & Engineering Faculty Publications

Term frequency – Inverse Document Frequency (TFIDF) is a vital first step in text analytics for information retrieval and machine learning applications. It is a memory-intensive and complex task due to the need to create and process a large sparse matrix of term frequencies, with the documents as rows and the term as columns and populate it with the term frequency of each word in each document.

The standard method of storing the sparse array is the “Compressed Sparse Row” (CSR), which stores the sparse array as three one-dimensional arrays for the row id, column id, and term frequencies. We …

Modeling And Numerical Simulations Of The Michigan Tech Convection Cloud Chamber, Subin Thomas

Dissertations, Master's Theses and Master's Reports

Understanding atmospheric clouds is essential for human progress, ranging from short-term effects such as when and how much it rains to long-term effects such as how much temperatures would rise due to global climate change. Clouds vary globally and seasonally; also they have length scales ranging from a few nanometers to a few kilometers and timescales from a few nanoseconds to a few weeks. Knowledge gaps in aerosol-cloud-turbulence interactions and a lack of sufficient resolution in observations pose a challenge in understanding cloud systems.

Experimental facilities like the Michigan Tech Cloud Chamber can provide a suitable platform for studying aerosol-cloud …

Multiscale Investigation Of Dropwise Condensation On A Smooth Hydrophilic Surface, Shahab Bayani Ahangar

Dissertations, Master's Theses and Master's Reports

The objective of this work is to identify the fundamental mechanism of dropwise condensation on a smooth solid surface by probing the solid-vapor interface during phase-change to evaluate the existence and structure of the thin film and the initial nucleus that develop during condensation. In this work, an automated Surface Plasmon Resonance imaging (SPRi) instrument with the ability to perform imaging in intensity modulation and angular modulation is developed. The SPRi instrument is used to probe (in three dimensions) the adsorbed film that forms on the substrate during dropwise condensation. SPRi with a lateral resolution of ~ 4-10 μm, thickness …

Investigating Ice Nucleation At Negative Pressures Using Molecular Dynamics: A First Order Approximation Of The Dependence Of Ice Nucleation Rate On Pressure, Elise Rosky

Dissertations, Master's Theses and Master's Reports

Atmospheric scientists and climate modelers are faced with uncertainty around the process of ice production in clouds. While significant progress has been made in predicting homogeneous and heterogeneous ice nucleation rates as a function of temperature, recent experiments have shown that ice nucleation rates can be enhanced without decreasing temperature, through various mechanical agitations. One hypothesis for these findings is that mechanisms of stretching water and thereby inducing negative pressure in the liquid could lead to an increase in freezing rate. To better understand the viability of this concept, the effect of negative pressure on ice nucleation rates needs to …

Cobalt, Molybdenum, And Nickel Complexes, Natural Zeolites, Epoxidation, And Free Radical Reactions, Nicholas K. Newberry

Dissertations, Master's Theses and Master's Reports

Chapter 2 is based on the synthesis and study of the compounds of the bidentate ligand ((5-phenyl-1H-pyrazol-3-yl)methyl)phosphine oxide with molybdenum and cobalt as the transition metal. The complexes were analyzed via FTIR, NMR, UV-Vis, Fluorescence Spectroscopy, TGA, DFT, and XRD. Chapter 3 resulted in the synthesis of the complexes [Ni(II)SSRRL](PF6)2 and [Ni(II)SRSRL](Cl)(PF6) of which [Ni(II)SRSRL](Cl)(PF6) had not been previously analyzed. Both products were analyzed via FTIR, NMR, UV-Vis, CV, DFT, and XRD. Chapter 5 contains the results of the characterization and modification of 4 natural zeolites (AZLB-Na, AZLB-Ca, NM-CA, NV-Na) from the United States in an attempt to increase the …

Accumulation-Type Ohmic Van Der Waals Contacts To Nearly Intrinsic Wse2, Upendra Rijal

Wayne State University Dissertations

We report the fabrication of ohmic van der Waals (vdW) contacts to WSe2 using degenerately p-doped MoS2 (p+-MoS2) as a contact-metal. We demonstrate in WSe2 field-effect transistors (FETs) that accumulation-type ohmic contacts and high device performance are achieved without electrostatically gating the drain/source contact regions despite the nearly intrinsic nature of WSe2. Back-gated WSe2 FETs with p+-MoS2 bottom-contacts (which screen the back-gate electric field in the drain/source regions) exhibit linear output characteristics, a high on/off ratio of 108, and a high two-terminal field-effect mobility up to ~200 cm2V-1s-1 at room temperature. Our theoretical modeling reveals that the p+-MoS2/WSe2 vdW contact …

Solving And Applications Of Multi-Facility Location Problems, Anuj Bajaj

Wayne State University Dissertations

This thesis is devoted towards the study and solving of a new class of multi-facility location problems. This class is of a great theoretical interest both in variational analysis and optimization while being of high importance to a variety of practical applications. Optimization problems of this type cannot be reduced to convex programming like, the much more investigated facility location problems with only one center. In contrast, such classes of multi-facility location problems can be described by using DC (difference of convex) programming, which are significantly more involved from both theoretical and numerical viewpoints.In this thesis, we present a new …

New Conforming Finite Elements Based On The De Rham Complexes For Some Fourth-Order Problems, Qian Zhang

Wayne State University Dissertations

In this dissertation, we discuss the conforming finite element discretization of high-order equations involving operators such as $(\curl\curl)^2$, $\grad\Delta\div$, and $-\curl\Delta\curl$. These operators appear in various models, such as continuum mechanics, inverse electromagnetic scattering theory, magnetohydrodynamics, and linear elasticity. Naively discretizing these operators and their corresponding eigenvalue problems using the existing $H^2$-conforming element would lead to spurious solutions in certain cases. Therefore, it is desirable to design conforming finite elements for equations containing these high-order differential operators.

The $\curl\curl$-conformity or $\grad\curl$-conformity requires that the tangential component of $\curl \bm u_h$ is continuous. Recall that the N\'ed\'elec element requires only the …

Thermal Atomic Layer Deposition Of Titanium Nitride Films: Synthesis And Characterization Of Novel Titanium Precursors, Anuththara Chalani Upeksha Abesinghe Arachchige

Wayne State University Dissertations

Due to the continuous miniaturization of microelectronic devices, robust deposition techniques are required which can provide continuous and conformal thin films even in high aspect ratio structures. Atomic Layer Deposition (ALD) is an excellent choice of deposition technique as it is capable of providing perfect film coverage. Because of its self-limited growth mechanism, ALD can afford sub-nanometer thickness control. Precursors used in ALD should be volatile, thermally stable at the deposition temperature, and highly reactive towards the co-regent. Traditionally, ALD has been used to grow metal oxide films. However, the microelectronics industry now demands ALD for metals and metal nitrides. …

Software As A Service: The Mediating Role Of Consequences Of Saas Diffusion On Firm Performance, Cristina Marie-Mccarthy Recchia

Wayne State University Dissertations

ABSTRACTSOFTWARE AS A SERVICE: THE MEDIATING ROLE OF CONSEQUENCES OF SAAS DIFFUSION ON FIRM PERFORMANCE by CRISTINA MARIE-MCCARTHY RECCHIA DECEMBER 2021 Advisor: Dr. Ratna Babu Chinnam Major: Industrial Engineering Degree: Doctor of Philosophy There are ample studies that support a positive link between information technology and firm performance. Bharadwaj (2000) and Chae (2014, 2018) are two examples that provided a foundation for this work. These scholars looked at how capabilities associated with information technology contribute to improved financial performance using a specific set of financial ratios. In addition, there are studies that examine a positive link between Software-as-a-Service (SaaS) and …

A Review Of Sample Size And Design Efficacy In Crossover Design In Peer-Reviewed Psychology Research, Kyle Moxley

Wayne State University Dissertations

A REVIEW OF SAMPLE SIZE AND DESIGN EFFICACY IN CROSSOVER DESIGN IN PEER-REVIEWED PSYCHOLOGY RESEARCHby KYLE C. MOXLEY November 2021 Advisor: Dr. Shlomo S. Sawilowsky Major: Education Evaluation and Research Degree: Doctor of Philosophy The present study seeks to investigate the efficacy of crossover research designs, and the application of crossover designs, in the field of behavioral sciences. Under ideal conditions, crossover designs are assumed to be more efficacious than parallel studies in that participants are given both treatments. However, the presence of carryover effects from treatments may influence outcomes (Jones & Kenward, 2014). To prevent carryover effects, researchers frequently …

Methods For Ad Hoc And Conversational Entity Retrieval From Knowledge Graphs, Fedor Nikolaev

Wayne State University Dissertations

The recent years have witnessed the increase in popularity of knowledge graphs in various applications, such as information extraction and retrieval systems, and intelligent assistants. Traditionally, retrieval from knowledge graphs is performed by submitting queries in SPARQL, a rigid query language based on triple patterns and logical operations. In this work, we propose several approaches to ad hoc and conversational entity retrieval that transcend the limitations of this approach by allowing the user to either submit queries using natural language in an ad hoc retrieval setting or have a conversation with an intelligent retrieval system by asking a series of …

Agn Jets And A Fanciful Trio Of Black Holes In The Abell 85 Brightest Cluster Galaxy, Juan P. Madrid

Physics and Astronomy Faculty Publications and Presentations

A new radio map of the Abell 85 Brightest Cluster Galaxy (BCG) was obtained with the Karl G. Jansky Very Large Array. With a resolution of 002, this radio image shows two kiloparsec-scale bipolar active galactic nucleus jets emanating from the active galactic nucleus of the A85 BCG. The galaxy core appears as a single entity on the new radio map. It has been assumed that the A85 BCG contained a binary black hole in its core. However, Chandra X-ray data and the new high-resolution radio map show no evidence that the A85 BCG harbors a binary black hole. The …

Enhancing Student Learning In Introductory Physics Through Funds Of Knowledge, Liang Zeng, Guang Zeng

Physics and Astronomy Faculty Publications and Presentations

Researchers have reported the funds of knowledge (FK) pedagogical approach effective in engaging minority students in learning. However, there are a lack of studies connecting FK to introductory college physics or physical science classes. By using examples from regional Mexican-American lived experiences at an Hispanic-serving institution located along the recently politicized U.S.-Mexico border, this paper provides evidence to show how physics educators can use FK to engage students in learning introductory college physics concepts.

Reducing Scattered Light In Ligo's Third Observing Run, S. Soni, C. Austin, A. Effler, R. M. S. Schofield, G. Gonzalez, V. V. Frolov, J. C. Driggers, A. Pele, A. L. Urban, G. Valdes, K. E. Ramirez

Physics and Astronomy Faculty Publications and Presentations

Noise due to scattered light has been a frequent disturbance in the advanced LIGO gravitational wave detectors, hindering the detection of gravitational waves. The non stationary scatter noise caused by low frequency motion can be recognized as arches in the time-frequency plane of the gravitational wave channel. In this paper, we characterize the scattering noise for LIGO and Virgo's third observing run O3 from April, 2019 to March, 2020. We find at least two different populations of scattering noise and we investigate the multiple origins of one of them as well as its mitigation. We find that relative motion between …

Pint: A Modern Software Package For Pulsar Timing, Jing Luo, S. M. Ransom, Paul B. Demorest, P. S. Ray, Anne M. Archibald, M. Kerr, Ross J. Jennings, Matteo Bachetti, Rutger Van Haasteren, Fredrick A. Jenet

Physics and Astronomy Faculty Publications and Presentations

Over the past few decades, the measurement precision of some pulsar timing experiments has advanced from ~10 μs to ~10 ns, revealing many subtle phenomena. Such high precision demands both careful data handling and sophisticated timing models to avoid systematic error. To achieve these goals, we present PINT (PINT Is Not Tempo3), a high-precision Python pulsar timing data analysis package, which is hosted on GitHub and available on the Python Package Index (PyPI) as pint-pulsar. PINT is well tested, validated, object oriented, and modular, enabling interactive data analysis and providing an extensible and flexible development platform for timing applications. …

Development Of A Real Time Human Face Recognition Software System, Askar Boranbayev, Seilkhan Boranbayev, Mukhamedzhan Amirtaev, Malik Baimukhamedov, Askar Nurbekov

Physics and Astronomy Faculty Publications and Presentations

In this study, a system for real-time face recognition was built using the Open Face tools of the Open CV library. The article describes the methodology for creating the system and the results of its testing. The Open CV library has various modules that perform many tasks. In this paper, Open CV modules were used for face recognition in images and face identification in real time. In addition, the HOG method was used to detect a person by the front of his face. After performing the HOG method, 128 face measurements were obtained using the image encoding method. A convolutional …

Grappling With Covid-19 By Imposing And Lifting Nonpharmaceutical Interventions In Sri Lanka: A Modeling Perspective, Mahesh Jayaweera, Chamath Dannongoda, Dilum Dilshan, Janith Dissanayake, Hasini Perera, Jagath Manatunge, Buddhika Gunawardana

Physics and Astronomy Faculty Publications and Presentations

The imposition and lifting of non-pharmaceutical interventions (NPIs) to avert the COVID19 pandemic have gained popularity worldwide and will continue to be enforced until herd immunity is achieved. We developed a linear regression model to ascertain the nexus between the time-varying reproduction number averaged over a time window of six days (Rts) and seven NPIs: contact tracing, quarantine efforts, social distancing and health checks, hand hygiene, wearing of facemasks, lockdown and isolation, and health-related supports. Our analysis suggests that the second wave that emerged in Sri Lanka in early October 2020 continued despite numerous NPIs. The model indicates that the …

Open Data From The First And Second Observing Runs Of Advanced Ligo And Advanced Virgo, Rich Abbott, Thomas D. Abbott, Amit Aich, Guldauren Bissenbayeva, Teviet Creighton, Mario C. Diaz, Malik Rakhmanov, Karla E. Ramirez, Palash K. Roy, Wenhui Wang, Adam Zadrozny

Physics and Astronomy Faculty Publications and Presentations

Advanced LIGO and Advanced Virgo are monitoring the sky and collecting gravitational-wave strain data with sufficient sensitivity to detect signals routinely. In this paper we describe the data recorded by these instruments during their first and second observing runs. The main data products are gravitational-wave strain time series sampled at 16384 Hz. The datasets that include this strain measurement can be freely accessed through the Gravitational Wave Open Science Center at http://gw-openscience.org, together with data-quality information essential for the analysis of LIGO and Virgo data, documentation, tutorials, and supporting software.

Search For Continuous Gravitational-Wave Signals In Pulsar Timing Residuals: A New Scalable Approach With Diffusive Nested Sampling, Yu-Yang Songsheng, Yi-Qian Qian, Yan-Rong Li, Pu Du, Jie-Wen Chen, Yan Wang, Soumya Mohanty, Jian-Min Wang

Physics and Astronomy Faculty Publications and Presentations

Detecting continuous nanohertz gravitational waves (GWs) generated by individual close binaries of supermassive black holes (CB-SMBHs) is one of the primary objectives of pulsar timing arrays (PTAs). The detection sensitivity is slated to increase significantly as the number of well-timed millisecond pulsars will increase by more than an order of magnitude with the advent of next-generation radio telescopes. Currently, the Bayesian analysis pipeline using parallel tempering Markov Chain Monte Carlo has been applied in multiple studies for CB-SMBH searches, but it may be challenged by the high dimensionality of the parameter space for future large-scale PTAs. One solution is to …

Bow Lake (Station 1 - Ledges) 2021 Water Quality Highlight Report, Amanda Mcquaid, Robert Craycraft

UNH Cooperative Extension

A Water Quality Highlight Report by UNH CE Lakes Lay Monitoring Program for Bow Lake, Station 1 Ledges (Barrington and Northwood, NH) for 2021.

Baboosic Lake 2021 Water Quality Highlight Report, Amanda Mcquaid, Robert Craycraft

UNH Cooperative Extension

A Water Quality Highlight Report by UNH CE Lakes Lay Monitoring Program for Baboosic Lake (Amherst and Merrimack, NH) for 2021.

Round Pond 2021 Water Quality Highlight Report, Amanda Mcquaid, Robert Craycraft

UNH Cooperative Extension

A Water Quality Highlight Report by UNH CE Lakes Lay Monitoring Program for Round Pond (Effingham, NH) in 2021.

Swains Lake (Site B) 2021 Water Quality Highlight Report, Amanda Mcquaid, Robert Craycraft

UNH Cooperative Extension

A Water Quality Highlight Report by UNH CE Lakes Lay Monitoring Program for Swains Lake (Station B) in Barrington, NH in 2021.

Proper 3-Colorings Of Cycles And Hypercubes, Emily Cairncross

Honors Papers

In this paper, we look at two families of graphs, cycles and hypercubes, and compare how their sets of proper 3-colorings differ as the graphs get arbitrarily large. In particular, we find the probability of pairs of vertices at various distances being the same color in order to understand the range and scale of interactions between them. As we look at larger and larger cycles, larger and larger hypercubes, patterns begin to emerge. While the colors of vertices fixed fractions of the cycle away from each other are independent, a random 3-coloring of the hypercube is essentially a 2-coloring. This …

Collaborative Game Mosaics, Xiaoyun Gong

Honors Papers

Imagine two players are playing a strategy board game. With one player holding black stones and the other player holding white stones, they take turns to place their pieces. After a while, they start to recognize some patterns. With three colors in front of them, black, white, and the color of the game board, they are curious about if they can form a recognizable image. Instead of playing the game to win, they start to collaborate with each other to form a mosaic. Later, they invite more players and provide them their own stones in different shades of gray. The …

Increasing The Value Of Information During Planning In Uncertain Environments, Gaurab Pokharel

Honors Papers

Prior studies have demonstrated that for many real-world problems, POMDPs can be solved through online algorithms both quickly and with near optimality [10, 8, 6]. However, on an important set of problems where there is a large time delay between when the agent can gather information and when it needs to use that information, these solutions fail to adequately consider the value of information. As a result, information gathering actions, even when they are critical in the optimal policy, will be ignored by existing solutions, leading to sub-optimal decisions by the agent. In this research, we develop a novel solution …

Quality Of Sql Code Security On Stackoverflow And Methods Of Prevention, Robert Klock

Honors Papers

This paper explores the frequency at which SQL/PHP posts on the website Stackoverflow.com contain code susceptible to SQL Injection, a common database vulnerability. Specifically, we analyze whether other users give notice of the vulnerability or provide an answer that is secure. The majority of questions analyzed were vulnerable to SQL Injection and were not corrected in their answers or brought to the attention of the original poster. To mitigate this, we present a machine learning bot which analyzes the poster’s code and alerts them of potential injection vulnerabilities, if necessary.

A Hybrid Decision Tree - Neural Network (Dt-Nn) Model For Predictive Maintenance Applications In Aircraft, Jarrod Carson

Honors Theses

As the Age of Information has evolved over the last several decades, the demand for technology which stores, analyzes, and utilizes data has increased substantially. For countless industries such as the medical, retail, and aircraft industries, such technology is crucial to their operation. This project proposes a hybrid machine learning model consisting of Decision Trees and Neural Networks which is able to classify data of varying volume and variety effectively and efficiently. The model’s structure consists of a decision tree with each node of the tree containing a neural network trained to classify a specific category of the output using …

Developing A Deterministic Polymorphic Circuit Generator Using Random Boolean Logic Expansion, Trinity Stroud

Honors Theses

Securing applications on untrusted platforms can involve protection against legitimate endusers who act in the role of malicious reverse engineers and hackers. Such adversaries have access to the full execution environment of programs, whether the program comes in the form of software or hardware. In this thesis, we consider the nature of obfuscating algorithms that perform iterative, stepwise transformation of programs into more complex forms that are intended to increase the complexity (time, resources) for malicious reverse engineers.

We consider simple Boolean logic programs as the domain of interest and examine a specific transformation technique known as Iterative Selection and …