Digital Commons Network^™

Preconditioned Iteractive Solvers For The 2d Helmholtz Equation Via Radial Basis Functions, Lina Wu

Publications and Research

In this paper, we discuss the solution solver for the linear system of equations arising from the discretized 2D Helmholtz equation using the radial basis functions. The coefficient matrix A that is generated from the discretization is dense and often ill-conditioned. This paper uses preconditioned iterative methods such as the General Minimal Residual method (GMRES) to solve the linear system. Different preconditioners are compared. Numerical experiments are conducted in order to provide a comparison of the convergence rates among various preconditioned linear systems. A further observation is made into the eigenvalue distributions and the choice of the shaping parameters during …

Magnetic-Field-Dependent Stimulated Emission From Nitrogen-Vacancy Centers In Diamond, Felix A. Hahl, Lukas Lindner, Xavier Vidal, Tingpeng Luo, Takeshi Ohshima, Shinobu Onoda, Shuya Ishii, Alexander M. Zaitsev, Marco Capelli, Brant C. Gibson, Andrew D. Greentree, Jan Jeske

Publications and Research

Negatively charged nitrogen-vacancy (NV) centers in diamond are promising magnetic field quantum sensors. Laser threshold magnetometry theory predicts improved NV center ensemble sensitivity via increased signal strength and magnetic field contrast. Here, we experimentally demonstrate laser threshold magnetometry. We use a macroscopic high-finesse laser cavity containing a highly NV-doped and low absorbing diamond gain medium that is pumped at 532 nm and resonantly seeded at 710 nm. This enables a 64% signal power amplification by stimulated emission. We test the magnetic field dependency of the amplification and thus demonstrate magnetic field-dependent stimulated emission from an NV center ensemble. This emission …

Legacy Lead In Urban Garden Soils: Communicating Risk And Limiting Exposure, Anna Paltseva, Zhongqi Cheng, Murray Mcbride, Maha Deeb, Sara Perl Egendorf, Peter M. Groffman

Advanced Science Research Center

Lead (Pb) exposure has long been recognized as a hazard to human health. Urban garden soils often contain elevated levels of Pb, mainly from legacy sources, which is a main barrier for urban gardening. The capacity of gardeners to access, understand, and act on scientific data related to soil contamination is also variable. This synthesis paper briefly summarizes the current scientific knowledge on soil Pb in urban gardens. Our objective is to produce clear recommendations about assessing actual risks and limiting exposure. First, we synthesize the nature and extent of soil contamination with Pb, and then describe how the bioavailability …

Danger: Wolf Crossing! Meantone Tuning And Froberger’S Keyboard Music, Stephen T. Ai

Student Theses

This thesis is an exploration of how tuning practices can influence compositional practice, focusing on the way temperament can provide new insights to a close reading of keyboard music by Johann Jakob Froberger (1616–67), a transitional figure between a predominantly meantone-oriented musical environment of the 17th century and the well temperament of the 18th century. Many scholars have pointed to Froberger’s characteristic chromaticism and experimentation with novel keys as indicative of his desire to compose beyond the restrictions of meantone tuning and towards well temperament. In an effort to move away from this oft-cited teleological narrative from unequal to equal, …

Assessment Of Spatial And Temporal Trends Of Exposure To Ambient Fine Particulate Matter And Ozone In New York/New Jersey Metropolitan Area, Subraham Singh

Dissertations and Theses

Background. Exposures to fine particulate matter (PM_2.5; particles with diameter less than 2.5 μm) and ozone (O₃) affect premature respiratory and cardiovascular mortality, morbidity and contribute to the development and progression of sub-clinical and clinical disease. Climate change affects air quality directly by modifying the thermodynamic properties of formation mechanisms and transport patterns, and indirectly, through increased emissions of PM_2.5 and O₃ precursors. The resultant changes in air quality influence human health outcomes through mechanisms of varying scale, timing, and complexity. PM_2.5 and O₃ levels have been declining due to the implementation …

Spotlight Report #6: Proffering Machine-Readable Personal Privacy Research Agreements: Pilot Project Findings For Ieee P7012 Wg, Noreen Y. Whysel, Lisa Levasseur

Publications and Research

What if people had the ability to assert their own legally binding permissions for data collection, use, sharing, and retention by the technologies they use? The IEEE P7012 has been working on an interoperability specification for machine-readable personal privacy terms to support this ability since 2018. The premise behind the work of IEEE P7012 is that people need technology that works on their behalf—i.e. software agents that assert the individual’s permissions and preferences in a machine-readable format.

Thanks to a grant from the IEEE Technical Activities Board Committee on Standards (TAB CoS), we were able to explore the attitudes of …

Investigation Of The Association Of Exposures To Fire-Related Hazards With Pulmonary Function Of Firefighters, David G. Goldfarb

Dissertations and Theses

Background. Firefighters are habitually exposed to hazardous toxicants which place them at an elevated risk for numerous adverse health outcomes. An example of this is the associations observed in other works between inhalation of combustion byproducts from urban structural fires and both acute and chronic pulmonary dysfunction. To-date, the characterization of firefighters’ exposures to dangerous chemicals in smoke from non-wildfire incidents, both directly through personal monitoring and indirectly from work-related records is scarce. Prior works investigating the association between routine firefighting and pulmonary function have relied on crude metrics such as years of service and numbers of responses to …

Weakly-Supervised Tumor Purity Prediction From Frozen H&E Stained Slides, Matthew Brendel, Vanesa Getseva, Majd Al Assaad, Michael Sigouros, Alexandros Sigaras, Troy Kane, Pegah Khosravi, Juan Miguel Mosquera, Olivier Elemento, Iman Hajirasouliha

Publications and Research

Background

Estimating tumor purity is especially important in the age of precision medicine. Purity estimates have been shown to be critical for correction of tumor sequencing results, and higher purity samples allow for more accurate interpretations from next-generation sequencing results. Molecular-based purity estimates using computational approaches require sequencing of tumors, which is both time-consuming and expensive.

Methods

Here we propose an approach, weakly-supervised purity (wsPurity), which can accurately quantify tumor purity within a digitally captured hematoxylin and eosin (H&E) stained histological slide, using several types of cancer from The Cancer Genome Atlas (TCGA) as a proof-of-concept.

Findings

Our model predicts …

Is The Phq-9 A Unidimensional Measure Of Depression? A 58,272-Participant Study, Renzo Bianchi, Jay Verkuilen, Sharon Toker, Irvin Sam Schonfeld, Markus Gerber, Elmar Brähler, Kurt Kroenke

Publications and Research

The PHQ-9 has become a measure of reference in depression research and clinical practice. However, the issue of the PHQ-9’s unidimensionality has not been fully elucidated, and the usability of the PHQ-9’s total score requires clarification. In this study, we examined the dimensionality, scalability, and monotonicity properties of the PHQ-9 as well as the scale’s total-score reliability. We did so based on exploratory structural equation modeling (ESEM) bifactor analysis and Mokken scale analysis (MSA). We relied on a total of 58,272 participants (63% female; Mage = 43, SDage = 13) from 29 samples involving seven different countries (e.g., Germany, the …

Professional Stem Identity, Achievement Goal Orientation, And Selfauthorship In Underrepresented Minority Undergraduate Stem Students, Christopher King

Theses and Dissertations

Post-secondary education is meant to build the cognitive and professional growth of the students studying all subjects. Yet, little is known about the development of how students think of themselves as members of the field, nor how they develop from a young novice to a person eligible for employment. A lens of self-authorship was used to compliment and interpret data collected regarding how students think of themselves as member of the STEM community (STEM Identity) and how they perceive their achievement STEM Identity. There was a significant link between student-mentor experiences and a higher professional identity and more progress along …

Investigating The Mechanisms Driving Mercury Reduction And Emissions In Soil, Hamil Patel

Student Theses

The water-induced emission of mercury from soil has been studied, but a complete understanding of the mechanisms driving mercury reduction and emission in soil has not been reached. The current understanding is an immediate expulsion of soil gaseous mercury upon water treatment and an upward transport of dissolved soil ionic mercury as the water evaporates. We analyzed emissions from several types of samples using various methods to further our understanding on the mechanisms involved. Light-induced emissions from aqueous samples of humic acid (HA) spiked with mercury (II) chloride (HgCl₂) showed that at higher concentrations of HA, less mercury …

Symmetry-Inspired Analysis Of Biological Networks, Ian Leifer

Dissertations, Theses, and Capstone Projects

The description of a complex system like gene regulation of a cell or a brain of an animal in terms of the dynamics of each individual element is an insurmountable task due to the complexity of interactions and the scores of associated parameters. Recent decades brought about the description of these systems that employs network models. In such models the entire system is represented by a graph encapsulating a set of independently functioning objects and their interactions. This creates a level of abstraction that makes the analysis of such large scale system possible. Common practice is to draw conclusions about …

Collaborative Learning With A Geometry Video Game: The Role Of Elaboration And Game Design In Motivation And Learning, Ethlyn Saltzman

Dissertations, Theses, and Capstone Projects

The study examined the effects of a new game mechanic on collaborative learning and mathematical discourse when playing a digital geometry puzzle game. For this study, two new versions of the game “Noobs vs. Leets” were developed. Both versions of the game teach the concepts of complementary and supplementary angles and the angle sum theorem of triangles. It was hypothesized that the version of the game that included a game mechanic that allow players to manipulate the angles, thus creating a more open-ended task, would be more intrinsically motivating, promote elaboration of the geometric concepts, and lead to greater learning …

Why, New York City? Gauging The Quality Of Life Through The Thoughts Of Tweeters, Sheryl Williams

Dissertations, Theses, and Capstone Projects

As a resource for social data, Twitter’s platform has been used to measure the quality of life through sentiment analysis. This capstone project explores another methodological technique—querying Twitter data around specific keyword terms to determine dominant topics, word patterns, and sentiment leanings in a geographical area. Focusing on New York City and Los Angeles for comparative analysis, the keyword term “why” will be used to build a Python analysis around topic modeling and sentiment analysis. Using this approach, the analysis reveals social and cultural differences, the overall sentiment of tweets, and subjects of interest to tweeters.

GitHub Repository for all …

Biomimetic And Medical Applications Of Hollow Nanoscale Structures, Justin Fang

Dissertations, Theses, and Capstone Projects

Materials whose structure incorporates nanoscale void spaces have multiple possible uses, whether in a bulk form or as individual particles, due to the combination of high surface area ratios and nanoscale material properties. This thesis will explore a few of these possibilities, concentrating on potential biomimetic and biomedical applications, for two materials: metal- organic frameworks and superparamagnetic iron oxide nanocages.

Metal-organic frameworks consist of metal ions such as Cu2+ which have highly porous lattice structures allowing them to absorb and release guest molecules such as peptides like diphenylalanine; this stored chemical energy can be turned into kinetic energy and used …

A Case For Comprehensive Work-Based Learning And Career Education For New York City’S Public High School Students, Jacqueline De La Cruz

Dissertations, Theses, and Capstone Projects

As children progress through grades K-12 they are often asked what they would like to be when they grow up, but there are few opportunities for exposure to real world work experiences while they are in school. While many radical scholars have critiqued the primacy of the economic goals of schooling, in this paper I embrace the connection between education and employability to advocate for career education and work-based learning programs to bolster students’ postsecondary plans. Work-based learning does not substitute traditional forms of education and schooling, but when aligned with tenets of learning and career theories, it has the …

Development Of Optical Nanomaterial For Enhanced Cerenkov Imaging, Qize Zhang

Dissertations, Theses, and Capstone Projects

Cancer is a significant public health problem worldwide and is the second leading cause of death in the United States. Imaging has increasingly been used over the last two decades to improve the diagnosis and guidance of tumor tissue removal surgery. Among the most widely used techniques for in vivo imaging are planar and tomographic fluorescence imaging and bioluminescence imaging. Despite their utility, these techniques are primarily restricted to preclinical use. Factors that have prevented translation from the bench to the bedside include depth-penetration considerations, regulatory issues, and toxicity. A recent development in nuclear imaging has been the ability to …

Exploring The Effectiveness Of Multiple-Exemplar Training For Visual Analysis Of Ab-Design Graphs, Verena S. Bethke

Dissertations, Theses, and Capstone Projects

In behavior analysis, data are usually analyzed using visual analysis of the graphed data. There are a wide range of methods used to visually analyze data, from a basic ‘textbook’ style approach to the use of visual aids, decision-rubrics, and computer-based approaches. In the literature, there have been some comparisons of the efficacy of different approaches. Visual analysis as a behavior can be taught using a variety of methods, independent of how the skill itself is to be performed. Teaching methods include lecture, online instruction, and equivalence-based instruction. There is not much research on the teaching of visual analysis specifically, …

Robert Rosen And Relational System Theory: An Overview, James Lennox

Dissertations, Theses, and Capstone Projects

Relational system theory is the science of organization and function. It is the study of how systems are organized which is based on their functions and the relations between their functions. The science was originally developed by Nicolas Rashevsky, and further developed by Rashevsky’s student Robert Rosen, and continues to be developed by Rosen’s student A. H. Louie amongst others. Due to its revolutionary character, it is often misunderstood, and to some, controversial. We will mainly be focusing on Rosen’s contributions to this science. The formal and conceptual setting for Rosen’s relational system theory is category theory. Rosen was the …

Cvemp Frequency Tuning In Adults Aged 60 And Above: A Systematic Review, Kiersten P. Dudman

Dissertations, Theses, and Capstone Projects

Objective: This systematic review aims to evaluate if there is a significant difference in the frequency specificity of cVEMP amplitude responses in the older adult population, and if so how clinical protocols should reflect age related changes in the vestibular system to properly assess for vestibular pathology.

Methods: A comprehensive search was conducted using various databases through the Mina Rees Library of the City University of New York’s Graduate Center. This search identified articles relevant to this systematic review. Inclusion criteria encompassed quantified studies that utilized various frequency tone bursts to elicit VEMP responses among several age groups.

Results: Three …

Thickened Surfaces, Checkerboard Surfaces, And Quantum Link Invariants, Joseph W. Boninger

Dissertations, Theses, and Capstone Projects

This dissertation has two parts, each motivated by an open problem related to the Jones polynomial. The first part addresses the Volume Conjecture of Kashaev, Murakami, and Murakami. We define a polynomial invariant, J^T_n, of links in the thickened torus, which we call the nth toroidal colored Jones polynomial, and we show J^T_n satisfies many properties of the original colored Jones polynomial. Most significantly, J^T_n exhibits volume conjecture behavior. We prove a volume conjecture for the 2-by-2 square weave, and provide computational evidence for other links. We also give two equivalent constructions …

Actual Causation: Apt Causal Models And Causal Relativism, Jennifer R. Mcdonald

Dissertations, Theses, and Capstone Projects

This dissertation begins by addressing the question of when a causal model is apt for deciding questions of actual causation with respect to some target situation. I first provide relevant background about causal models, explain what makes them promising as a tool for analyzing actual causation, and motivate the need for a theory of aptness as part of such an analysis (Chapter 1). I then define what it is for a model on a given interpretation to be accurate of, that is, say only true things about, some target situation. This involves a systematization of various representational principles …

Understanding Coastal And Inland Hydrometeorological Hazards Produced By Extratropical And Tropical Cyclones Along The East Coast Of The United States, Katherine Towey

Dissertations, Theses, and Capstone Projects

As global temperatures continue to rise, the effects of anthropogenic climate change will impact the magnitude and frequency of pluvial, fluvial, and coastal flooding events. If we want to accurately predict changes in these flooding events, we need to fully understand them in the current climate. As such, this research examines the relationship between hydrometeorological hazards and the characteristics of the storm types, such as extratropical cyclones (ETCs) and tropical cyclones (TCs), that produce such hazards. Through the use of observational and reanalysis data, the work herein utilizes a cyclone-hazard association algorithm and extreme value analysis to assess the extent, …

Landscape, Settlement, And Community: The Natural, Human, And Sacred Geography Of Classic Maya Civilization In West-Central Guatemala, Marc A. Wolf

Dissertations, Theses, and Capstone Projects

This dissertation explores the fluid and commonly multi-compositional aspects of Maya settlement patterns, which reflect concepts of space within Maya worldviews. Research will be focused on the predominantly Classic (ca. AD 650-810) era archaeological site of Cancuen and its neighbors in the Verapaz department of Guatemala. These settlements provide a complex arena where questions of identity, spirituality, and ethnic affiliations can be addressed within a spatial context. The continuing detailed settlement and environmental survey mapping within the Cancuen region is the primary source of evidence from which a more thorough appreciation of emic Maya spatial considerations will be investigated.

The …

Collective Behavior Of Dissipatively-Coupled Photonic Oscillator Networks, Jiajie Ding

Dissertations, Theses, and Capstone Projects

This thesis discusses the collective behavior of networks formed by photonic oscillators. The key motivations for doing this research are the interest in developing high power laser arrays on photonic chips and performing optical computing.

Equitable Assessment For Elementary Dual-Language Learners, Joliette Mandel

Dissertations, Theses, and Capstone Projects

This thesis points out the contradictions between the goals of standardized testing and the goals of dual-language elementary education. I argue that dual-language elementary schools in the New York City Department of Education would be better served by a performance assessment model to measure student and school accountability for several reasons. Performance assessment is more equitable for students who are marginalized by their race, language, or class. Many students who attend dual-language schools in the NYCDOE fall into all these categories. I will discuss in depth why standardized testing is failing students, particularly those in dual-language elementary programs. Next, I …

The Zariski-Riemann Space As A Universal Model For The Birational Geometry Of A Function Field, Giovan Battista Pignatti Morano Di Custoza

Dissertations, Theses, and Capstone Projects

Given a function field $K$ over an algebraically closed field $k$, we propose to use the Zariski-Riemann space $\ZR (K/k)$ of valuation rings as a universal model that governs the birational geometry of the field extension $K/k$. More specifically, we find an exact correspondence between ad-hoc collections of open subsets of $\ZR (K/k)$ ordered by quasi-refinements and the category of normal models of $K/k$ with morphisms the birational maps. We then introduce suitable Grothendieck topologies and we develop a sheaf theory on $\ZR (K/k)$ which induces, locally at once, the sheaf theory of each normal model. Conversely, given a sheaf …

The Effects Of Education And Cognitive Skills On Employability And Earnings For Labor Market Entrants: Evidence From Large-Scale Worldwide Survey Data, Yongchao Zhao

Dissertations, Theses, and Capstone Projects

People’s stock of knowledge, abilities, and other personal characteristics, namely human capital, has been widely regarded as a fundamental input to both individuals' ability to earn a living and to fuel economic growth. Traditionally, formal education has been widely considered as a good investment in human capital and an extensive literature has shown that it has a positive and strong association with labor market success. However, considering the global knowledge economy, which emphasizes skills and knowledge, the economic benefits of formal education are being questioned, as findings from recent research reviews revealed that the overall rate of return to education …

When The Elite Control Public Education: A Critical Inquiry On Charter Schools, Marisela Palafox

Dissertations, Theses, and Capstone Projects

This thesis takes a critical look into charter schools in New York City. Through this thesis, I want to answer questions regarding who benefits from the current charter school model in NYC and why this current state of schooling is detrimental to marginalized children. As a former NYC public school student, I know first-hand that good intentions by white educators (and thus white systems) do not always result in beneficial outcomes for the most vulnerable.

Symmetries, Zero Modes And Light Transport In Non-Hermitian Photonics, Jose David Hernandez Rivero

Dissertations, Theses, and Capstone Projects

We approach some fundamental aspects of photonic dissipative systems treated by a non-Hermitian theory. Inspired by the possibilities provided by some major non-Hermitian symmetries, we study systematically the properties of the novel pseudochirality, pseudo-anti-Hermiticity, and supersymmetry. We analyze other aspect of photonics, the zero mode, which has a profound connection to non-Hermitian physics. We propose a scheme to realize a zero mode that exists even in the absence of symmetries. Finally, we approach light transport in non-Hermitian photonic systems, where the introduction of gain and loss can modify drastically the propagation speed of wavepackets.