Physical Sciences and Mathematics Commons^™

Combinatorial Optimization With Photonics-Inspired Clock Models, Mostafa Honari-Latifpour, Matthew S. Mills, Mohammad-Ali Miri

Publications and Research

NP-hard combinatorial optimization problems are in general hard problems that their computational complexity grows faster than polynomial scaling with the size of the problem. Thus, over the years there has been a great interest in developing unconventional methods and algorithms for solving such problems. Here, inspired by the nonlinear optical process of q-photon down-conversion, in which a photon is converted into q degenerate lower energy photons, we introduce a nonlinear dynamical model that builds on coupled single-variable phase oscillators and allows for efficiently approximating the ground state of the classical q-state planar Potts Hamiltonian. This reduces the exhaustive search in …

A Novel Tropical Geometry-Based Interpretable Machine Learning Method: Pilot Application To Delivery Of Advanced Heart Failure Therapies, Heming Yao, Harm Derkson, Jessica R. Golbus, Justin Zhang, Keith D. Aaronson, Jonathan Gryak, Kayvan Najarian

Publications and Research

Abstract—A model’s interpretability is essential to many practical applications such as clinical decision support systems. In this paper, a novel interpretable machine learning method is presented, which can model the relationship between input variables and responses in humanly understandable rules. The method is built by applying tropical geometry to fuzzy inference systems, wherein variable encoding functions and salient rules can be discovered by supervised learning. Experiments using synthetic datasets were conducted to demonstrate the performance and capacity of the proposed algorithm in classification and rule discovery. Furthermore, we present a pilot application in identifying heart failure patients that are eligible …

Technical Note: Novel Estimates Of The Leaf Relative Uptake Rate Of Carbonyl Sulfide From Optimality Theory, Georg Wohlfahrt, Albin Hammerle, Felix M. Spielmann, Florian Kitz, Chuixiang Yi

Publications and Research

In order to estimate the gross primary productivity (GPP) of terrestrial ecosystems from the canopy uptake of carbonyl sulfide (COS), the leaf relative uptake rate (LRU) of COS with respect to carbon dioxide needs to be known a priori. Currently, the variability of the LRU between plant species in different biomes of the world is poorly understood, making the choice of an appropriate LRU uncertain and hampering further progress towards developing COS as an alternative tracer of GPP. Here we propose a novel approach for estimating LRU based on plant optimality principles, validate it against in situ leaf gas exchange …

Probing The Production Of Intracellular Vesicles Containing Reactive Oxygen And Nitrogen Species By Electrochemical Resistive-Pulse Sensing, Rui Jia

Publications and Research

No abstract provided.

A Real-Time 3d Object Detection, Recognition And Presentation System On A Mobile Device For Assistive Navigation, Jin Chen

Dissertations and Theses

This thesis proposes an integrated solution for 3D object detection, recognition, and presentation to increase accessibility for various user groups in indoor areas through a mobile application. The system has three major components: a 3D object detection module, an object tracking and update module, and a voice and AR-enhanced interface. The 3D object detection module consists of pre-trained 2D object detectors and 3D bounding box estimation methods to detect the 3D poses and sizes of the objects in each camera frame. This module can easily adapt to various 2D object detectors (e.g., YOLO, SSD, Mask RCNN) based on the requested …

Biomedical Applications Of Lanthanide Nanomaterials, For Imaging, Sensing And Therapy, Qize Zhang, Stephen O'Brien, Jan Grimm

Publications and Research

The application of nanomaterials made of rare earth elements within biomedical sciences continues to make significant progress. The rare earth elements, also called the lanthanides, play an essential role in modern life through materials and electronics. As we learn more about their utility, function, and underlying physics, we can contemplate extending their applications to biomedicine. This particularly applies to diagnosis and radiation therapy due to their relatively unique features, such as an ultra-wide Stokes shift in the luminescence, variable magnetism and potentially tunable properties, due to the library of lanthanides available and their multivalent oxidation state chemistry. The ability to …

Analysis Of Blue Fountain Pen Ink By Uv-Vis Spectroscopy, Atr-Ftir Spectroscopy, And Thin Layer Chromatography Enhanced With Rgb Spot Evaluation To Construct A Database For Comparison And Identification., Elliot D. Quinteros

Dissertations and Theses

Pen ink can be a crucial piece of physical evidence in the area of Forensic Science. For example, evidence such as notes, letters, printed documents, checks, currency, ransom notes, and books may contain ink. Analysis of ink is typically done for identification or differentiation purposes. To improve existing methods, it was proposed to create a database with many samples and experimental information. The methods used and evaluated were thin-layer chromatography (TLC) enhanced with RGB spot evaluation, UV-Vis spectroscopy, and ATR-FTIR spectroscopy. All three methods were used to analyze 89 fountain pen ink samples. All three methods were able to discriminate …

Sea Surface Temperatures And Vertical Wind Shear As Precursors To Tropical Cyclone Activity In The Caribbean And An Expanding Main Developing Region, Keneshia Hibbert

Dissertations and Theses

Sea surface temperatures and vertical wind shear are essential to tropical cyclone formation. TCs need warm SSTs and low shear for genesis. Increasing SSTs and VWS changes influence storm development. This work analyzes SST and VWS trends for the Caribbean, surrounding region, and the Atlantic hurricane main developing region from 1982 to 2020. Storm intensity increases significantly during this period. Annual and seasonal trends show regional SSTs in the MDR are warming annually (0.0219°C yr^-1) and per season (0.0280°C yr^-1). Simultaneously, VWS decreases during the late rainfall season at 0.0556m/s yr^-1 in the MDR and …

A Citizen-Science Approach For Urban Flood Risk Analysis Using Data Science And Machine Learning, Candace Agonafir

Dissertations and Theses

Street flooding is problematic in urban areas, where impervious surfaces, such as concrete, brick, and asphalt prevail, impeding the infiltration of water into the ground. During rain events, water ponds and rise to levels that cause considerable economic damage and physical harm. The main goal of this dissertation is to develop novel approaches toward the comprehension of urban flood risk using data science techniques on crowd-sourced data. This is accomplished by developing a series of data-driven models to identify flood factors of significance and localized areas of flood vulnerability in New York City (NYC). First, the infrastructural (catch basin clogs, …

Poly(Β-Gal-Thr): A New Scalable Synthetic Mucin, Manuel A. Lema

Dissertations and Theses

A method for the preparation of glycosylated polypeptides via the nucleophilic ring-opening polymerization of a glycosylated N-carboxyanhydride (NCA) monomer is reported. The synthesis of 2,3,4,6-tetraacetyl-β-galactose-threonine N-carboxyanhydride (β-AcO-Gal-Thr-NCA) monomer in 5 steps with an 8 % overall yield is described, and the single-crystal X-ray structure is provided. The effect of a series of Ni⁰-based organometallic initiators, nucleophilic amine initiators, co-catalysts, and solvents on the polymerization were explored. The kinetics of the three most promising conditions were studied in greater detail. The conditions that provided the highest yield, low polydispersity (Ð), and …

A Temporal Examination Of The Connections Between Convective Available Potential Energy And Convective System Development, Chad A. Small

Dissertations and Theses

In 1983, the World Climate Research Programme launched its first project: the International Satellite Cloud Climatology Project (ISCCP). While the ISCCP has succeeded in many of its cataloging and analytical goals, one of its flagship products, the Convection Tracking (CT) Database does not contain certain environmental parameters that are essential in understanding how, and when, convection is initiated or intensified. The development of mesoscale convection – notably, convective systems (CS) – is also largely dependent on parameters like convective available potential energy (CAPE) which the ISCCP CT Database does not record. By tying information on CAPE to CS, discoveries in …

Evaluation Of Snow And Streamflow In The National Water Model With Analysis Using Machine Learning, Engela Sthapit

Dissertations and Theses

Snow has great influence on land-atmosphere interactions and snowmelt from the mountains is a vital water source for downstream communities dependent on snow fed lakes, rivers and streams. This study explored the snow and streamflow prediction capabilities of process-based numerical prediction and data-driven machine learning models.

The overall goal of this study was to understand the deficiencies in the NOAA’s National Water Model (NWM) to represent snow, subsequently streamflow, and recognize the areas where it could be improved for future model developments. The goal was also to evaluate if the recent advancements in machine learning techniques is useful for predicting …

Data Fusion And Synergy Of Active And Passive Remote Sensing; An Application For Freeze Thaw Detections, Zahra Sharifnezhadazizi

Dissertations and Theses

There has been a recent evolvement in the field of remote sensing after increase of number satellites and sensors data which could be fused to produce new data and products. These efforts are mainly focused on using of simultaneous observations from different platforms with different spatial and temporal resolutions. The research dissertation aims to enhance the synergy use of active and passive microwave observations and examine the results in detection land freeze and thaw (FT) predictions. Freeze thaw cycles particularly in high-latitude regions have a crucial role in many applications such as agriculture, biogeochemical transitions, hydrology and ecosystem studies. The …

Understanding The Relationship Between Urban Areas And The Boundary Layer Using Remote Sensing Methods, Gabriel A. Rios

Dissertations and Theses

The atmospheric boundary layer is crucial to the exchange in energy between the Earth's surface and the atmosphere. Within this layer, the majority of human activities are carried out, which makes understanding the boundary layer especially important for many of our interests. A key component of this energy exchange is found at the surface, was surface properties are the interface through which momentum, heat, moisture, and other fluxes are transferred between media. Not only does the surface act as an interface, but as an actor that influences the exchange efficiency and rates. This concept is the crux of atmospheric boundary …

Nonlinear Light - Matter Interactions Of Ultrafast High Intensity Laser Pulses, Henry Meyer

Dissertations and Theses

This thesis focuses on the key nonlinear optical effects that arise from the interactions of intense ultrafast laser pulses with various states of matter. These interactions involve electronic and molecular states and yield new information on the underlying fundamental processes that govern the molecular world. Modern day lasers offer ultrashort pulses, high intensities, and complex polarizations and wavefronts. These extreme conditions have profound effect on the optical properties and behaviors of electronic and molecular states within a material. The changes in these mechanisms effect generation of nonlinear optics, such supercontinuum (SC), stimulated Raman (SRS), self-focusing and filamentation, conical emission (CE), …

Towards Simulation Of Complex Ocean Flows: Analysis And Algorithm For Computation Of Coupled Partial Differential Equations, Wenbin Dong

Dissertations and Theses

The hybrid CFD models which usually consist of 2 sub-models, develop our capability to simulate many emerging problems with multiphysics and multiscale flows, especially for the coastal ocean flows interacted with local phenomena of interest. For most cases, the sub-models are connected with direct interpolation which is easy and workable. It becomes urgently needed to investigate the inner mechanism of such model integration as this simple method does not work well if the two sub-models are different in governing equations, numerical methods, and computational grids. Also, it can not treat complex flow structures as well as the balance in mass …

Amm Problem #12279, Brad Isaacson

Publications and Research

No abstract provided.

Using Data Science Tools For Investigating Chat Logs From The Conti Ransomware Group, Boyan Kostadinov, Joseph Liu, Julio Rayme

Publications and Research

The main goal of this paper is to showcase some results from a comprehensive data analysis that we did on the cache of chat logs from the notorious ransomware group Conti. The chat logs were made publicly available on February 27, 2022. They were translated from Russian into English, and contain 393 json files with chat logs from the instant messaging service Jabber. We employ a variety of modern data science tools for text mining, natural language processing, network analysis and geospatial analysis to investigate the Conti chat logs so that we can understand the command and control structure of …

Characterizing Changes In Extreme Ozone Levels Under 2050s Climate Conditions: An Extreme-Value Analysis In California, Bradley Wilson, Mariah Pope, Jeremy R. Porter, Edward Kearns, Evelyn Shu, Mark Bauer, Neil Freeman, Mike Amodeo, David Melecio-Vazquez, Ho Hsieh, Maggie Tarasovitch

Publications and Research

Ground-level ozone has a well established climate penalty associated with changing meteorological conditions under future climate change, but most existing research focuses exclusively on ozone-temperature relationships defined at specific locations. Using an extreme-value theory approach, we model relationships between temperature, humidity, and vapor pressure deficit and maximum daily 8 h ozone concentrations (MDA8) across California using a combination of ozone station network data and Community Multiscale Air Quality Modeling System (CMAQ) model output from 2008 to 2017. We use a spatial regression with time varying bias coefficients to fuse station observations and modeled output into a spatially explicit gridded ozone …

Satellite Evidence Of Canopy-Height Dependence Of Forest Drought Resistance In Southwestern China, Peipei Xu, Wei Fang, Tao Zhou, Hu Li, Xiang Zhao, Spencer Berman, Ting Zhang, Chuixiang Yi

Publications and Research

The frequency and intensity of drought events are increasing with warming climate, which has resulted in worldwide forest mortality. Previous studies have reached a general consensus on the size-dependency of forest resistance to drought, but further understanding at a local scale remains ambiguous with conflicting evidence. In this study, we assessed the impact of canopy height on forest drought resistance in the broadleaf deciduous forest of southwestern China for the 2010 extreme drought event using linear regression and a random forest (RF) model. Drought condition was quantified with standardized precipitation evapotranspiration index (SPEI) and drought resistance was measured with the …

Automatic Cephalometric Landmark Detection On X-Ray Images Using Object Detection, Cheng-Ho King, Yin-Lin Wang, Chia-Ling Tsai

Publications and Research

We propose a new deep convolutional cephalometric landmark detection framework for orthodontic treatment. Our proposed method consists of two major steps: landmark detection using a deep neural network for object detection, and landmark repair to ensure one instance per landmark class. For landmark detection, we modify the loss function of the backbone network YOLOv3 to eliminate the constrains on the bounding box and incorporate attention mechanism to improve the detection accuracy. For landmark repair, a triangle mesh is generated from the average face to eliminate superfluous instances, followed by estimation of missing landmarks from the detected ones using Laplacian Mesh. …

Bft2: A General Class Of 2d N = (0, 2) Theories, 3-Manifolds And Toric Geometry, Sebastían Franco, Xingyang Yu

Publications and Research

We introduce and initiate the study of a general class of 2d N = (0, 2) quiver gauge theories, defined in terms of certain 2-dimensional CW complexes on oriented 3- manifolds. We refer to this class of theories as BFT₂’s. They are natural generalizations of Brane Brick Models, which capture the gauge theories on D1-branes probing toric Calabi-Yau 4-folds. The dynamics and triality of the gauge theories translate into simple transformations of the underlying CW complexes. We introduce various combinatorial tools for analyzing these theories and investigate their connections to toric Calabi-Yau manifolds, which arise as their …

Perspectives On Determinism In Quantum Mechanics: Born, Bohm, And The 'Quantal Newtonian' Laws, Viraht Sahni

Publications and Research

Quantum mechanics has a deterministic Schrödinger equation for the wave function. The Göttingen-Copenhagen statistical interpretation is based on the Born Rule that interprets the wave function as a ‘probability amplitude’. A precept of this interpretation is the lack of determinism in quantum mechanics. The Bohm interpretation is that the wave function is a source of a field experienced by the electrons, thereby attributing determinism to quantum theory. In this paper we present a new perspective on such determinism. The ideas are based on the equations of motion or ‘Quantal Newtonian’ Laws obeyed by each electron. These Laws, derived from the …

The Octagon At Large M, Riccardo Argurio, Matteo Bertolini, Sebastían Franco, Eduardo García-Valdecasas, Shani Meynet, Antoine Pasternak, Valdo Tatitscheff

Publications and Research

Recently, the first instance of a model of D-branes at Calabi-Yau singularities where supersymmetry is broken dynamically into stable vacua has been proposed. This construction was based on a system of N regular and M = 1 fractional branes placed at the tip of the so-called (orientifolded) Octagon singularity. In this paper we show that this model admits a large M generalization, having the same low energy effective dynamics. This opens up the possibility that the effect on geometry is smooth, and amenable to describing the gauge theory all along the RG flow, including the deep IR, in terms of …

Strain‑Induced Quantum Hall Phenomena Of Excitons In Graphene, Oleg L. Berman, Roman Ya. Kezerashvili, Yurii E. Lozovik, Klaus G. Ziegler

Publications and Research

We study direct and indirect pseudomagnetoexcitons, formed by an electron and a hole in the layers of gapped graphene under strain‑induced gauge pseudomagnetic field. Since the train‑induced pseudomagnetic field acts on electrons and holes the same way, it occurs that the properties of single pseudomagnetoexcitons, their collective effects and phase diagram are cardinally different from those of magnetoexcitons in a real magnetic field. We have derived wave functions and energy spectrum of direct in a monolayer and indirect pseudomagnetoexcitons in a double layer of gapped graphene. The quantum Hall effect for direct and indirect excitons was predicted in the monolayers …

Extractable Entanglement From A Euclidean Hourglass, Takanori Anegawa, Norihiro Iizuka, Daniel Kabat

Publications and Research

We previously proposed that entanglement across a planar surface can be obtained from the partition function on a Euclidean hourglass geometry. Here we extend the prescription to spherical entangling surfaces in conformal field theory. We use the prescription to evaluate log terms in the entropy of a conformal field theory in two dimensions, a conformally coupled scalar in four dimensions, and a Maxwell field in four dimensions. For Maxwell we reproduce the extractable entropy obtained by Soni and Trivedi. We take this as evidence that the hourglass prescription provides a Euclidean technique for evaluating extractable entropy in quantum field theory.

Superluminal Propagation On A Moving Braneworld, Brian Greene, Daniel Kabat, Janna Levin, Arjun S. Menon

Publications and Research

We consider a braneworld scenario in the simplest setting, M₄ × S¹, with a four-dimensional (4D) Minkowski metric induced on the brane, and establish the possibility of superluminal propagation. If the brane is at rest, the 4D Lorentz symmetry of the brane is exact, but if the brane is in motion, it is broken globally by the compactification. By measuring bulk fields, an observer on the brane sees a slice through a higher-dimensional field profile, which carries an imprint of the extra dimensions even when the brane is at rest. If the brane is in motion, we …

Exploratory Programming In The Arts And Humanities [Book Review], Kelly Hammond

Publications and Research

Exploratory Programming is a testament to what open-access can mean, especially in an e-learning environment. Used in full, it is a free course (that relies on free and open software) from a gifted MIT professor whose pedagogy is clear in structure and tone. He scaffolds, promotes predictive thinking, lauds collaborative learning, and urges readers to do not just to read. Used in part, it can be equally powerful.

Defining Entanglement Without Tensor Factoring: A Euclidean Hourglass Prescription, Takanori Anegawa, Norihiro Iizuka, Daniel Kabat

Publications and Research

We consider entanglement across a planar boundary in flat space. Entanglement entropy is usually thought of as the von Neumann entropy of a reduced density matrix, but it can also be thought of as half the von Neumann entropy of a product of reduced density matrices on the left and right. The latter form allows a natural regulator in which two cones are smoothed into a Euclidean hourglass geometry. Since there is no need to tensor factor the Hilbert space, the regulated entropy is manifestly gauge invariant and has a manifest state-counting interpretation. We explore this prescription for scalar fields, …

Two-Loop Four-Fermion Scattering Amplitude In Qed, R. Bonciani, A. Broggio, S. Di Vita, A. Ferroglia, M. K. Mandal, P. Mastrolia, L. Mattiazzi, A. Primo, J. Ronca, U. Schubert, W. J. Torres Bobadilla, F. Tramontano

Publications and Research

We present the first fully analytic evaluation of the transition amplitude for the scattering of a massless into a massive pair of fermions at the two-loop level in quantum electrodynamics. Our result is an essential ingredient for the determination of the electromagnetic coupling within scattering reactions, beyond the currently known accuracy, which has a crucial impact on the evaluation of the anomalous magnetic moment of the muon. It will allow, in particular, for a precise determination of the leading hadronic contribution to the (g − 2)_μ in the MUonE experiment at CERN, and therefore can be used to …