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Articles 13771 - 13800 of 302421

Full-Text Articles in Physical Sciences and Mathematics

How Object Segmentation And Perceptual Grouping Emerge In Noisy Variational Autoencoders, Ben Lonnqvist, Zhengqing Wu, Michael H. Herzog May 2023

How Object Segmentation And Perceptual Grouping Emerge In Noisy Variational Autoencoders, Ben Lonnqvist, Zhengqing Wu, Michael H. Herzog

MODVIS Workshop

Many animals and humans can recognize and segment objects from their backgrounds. Whether object segmentation is necessary for object recognition has long been a topic of debate. Deep neural networks (DNNs) excel at object recognition, but not at segmentation tasks - this has led to the belief that object recognition and segmentation are separate mechanisms in visual processing. Here, however, we show evidence that in variational autoencoders (VAEs), segmentation and faithful representation of data can be interlinked. VAEs are encoder-decoder models that learn to represent independent generative factors of the data as a distribution in a very small bottleneck layer; …


Evaluating Models Of Scanpath Prediction, Matthias Kümmerer, Matthias Bethge May 2023

Evaluating Models Of Scanpath Prediction, Matthias Kümmerer, Matthias Bethge

MODVIS Workshop

No abstract provided.


A Dynamical Model Of Binding In Visual Cortex During Incremental Grouping And Search, Daniel Schmid, Daniel A. Braun, Heiko Neumann May 2023

A Dynamical Model Of Binding In Visual Cortex During Incremental Grouping And Search, Daniel Schmid, Daniel A. Braun, Heiko Neumann

MODVIS Workshop

Binding of visual information is crucial for several perceptual tasks. To incrementally group an object, elements in a space-feature neighborhood need to be bound together starting from an attended location (Roelfsema, TICS, 2005). To perform visual search, candidate locations and cued features must be evaluated conjunctively to retrieve a target (Treisman&Gormican, Psychol Rev, 1988). Despite different requirements on binding, both tasks are solved by the same neural substrate. In a model of perceptual decision-making, we give a mechanistic explanation for how this can be achieved. The architecture consists of a visual cortex module and a higher-order thalamic module. While the …


In Quest Of A Shared Planet: Negotiating Climate From The Global South, Naveeda Khan May 2023

In Quest Of A Shared Planet: Negotiating Climate From The Global South, Naveeda Khan

Literary Studies

Based on the author’s eight years of fieldwork with the United Nations-led Conference of Parties (COP), In Quest of a Shared Planet offers an illuminating first-person ethnographic perspective on climate change negotiations. Focusing on the Paris Agreement, anthropologist Naveeda Khan introduces readers to the only existing global approach to the problem of climate change, one that took nearly thirty years to be collectively agreed upon. She shares her detailed descriptions of COP21 to COP25 and growing understanding of the intricacies of the climate negotiation process, leading her to ask why countries of the Global South invested in this slow-moving process …


Revisiting The Definition Of Field Capacity As A Functional Parameter In A Layered Agronomic Soil Profile Beneath Irrigated Maize, Paolo Nasta, Trenton E. Franz, Justin P. Gibson, Nunzio Romano May 2023

Revisiting The Definition Of Field Capacity As A Functional Parameter In A Layered Agronomic Soil Profile Beneath Irrigated Maize, Paolo Nasta, Trenton E. Franz, Justin P. Gibson, Nunzio Romano

School of Natural Resources: Faculty Publications

The soil water content at the condition of field capacity (θFC) is a key parameter in irrigation scheduling and has been suggested to be determined by running a synthetic drainage experiment until the flux rate (q) at the bottom of the soil profile achieves a predefined negligible value (qFC). We question the impact of qFC on the assessment of field capacity. Moreover, calculating θFC as the integral mean of the water content profile when q is equal to qFC is strictly valid only for uniform soil profiles. By contrast, …


Synthesis And Characterization Of Porphyrin-Encapsulated Nanoparticles: Investigations With Scanning Probe Microscopy, Olajumoke Helen Olubowale May 2023

Synthesis And Characterization Of Porphyrin-Encapsulated Nanoparticles: Investigations With Scanning Probe Microscopy, Olajumoke Helen Olubowale

LSU Doctoral Dissertations

Scanning probe microscopy (SPM) encompasses a family of surface measurements that use a sharp probe to “feel” a surface. The tip is scanned point-by-point to build a map of the sample topography, which can be correlated with local measurements of surface properties. This dissertation outlines the history of SPM and describes techniques, operational modes, and applications. A review of force volume mapping (FVM), a 3D characterization mode of SPM used to map material properties detailed. Force volume mapping can be achieved by measuring multiple force measurements point-by-point in a grid pattern. Local properties such as chemical forces, dielectric properties, nanomechanical …


Method Of Evanescently Coupling Whispering Gallery Mode Optical Resonators Using Liquids, Hengky Chandrahalim, Kyle T. Bodily May 2023

Method Of Evanescently Coupling Whispering Gallery Mode Optical Resonators Using Liquids, Hengky Chandrahalim, Kyle T. Bodily

AFIT Patents

The present invention relates to evanescently coupling whispering gallery mode optical resonators having a liquid coupling as well as methods of making and using same. The aforementioned evanescently coupling whispering gallery mode optical resonators having a liquid couplings provide increased tunability and sensing selectivity over current same. The aforementioned. Applicants’ method of making evanescent-wave coupled optical resonators can be achieved while having coupling gap dimensions that can be fabricated using standard photolithography. Thus economic, rapid, and mass production of coupled WGM resonators-based lasers, sensors, and signal processors for a broad range of applications can be realized.


Cms Pythia 8 Colour Reconnection Tunes Based On Underlying-Event Data, A. Tumasyan May 2023

Cms Pythia 8 Colour Reconnection Tunes Based On Underlying-Event Data, A. Tumasyan

Department of Physics and Astronomy: Faculty Publications

New sets of parameter tunes for two of the colour reconnection models, quantum chromodynamics-inspired and gluon-move, implemented in the pythia 8 event generator, are obtained based on the default CMS pythia 8 underlying-event tune, CP5. Measurements sensitive to the underlying event performed by the CMS experiment at centre-of-mass energies √ s = 7 and 13 TeV, and by the CDF experiment at 1.96 TeV are used to constrain the parameters of colour reconnection models and multiple-parton interactions simultaneously. The new colour reconnection tunes are compared with various measurements at 1.96, 7, 8, and 13 TeV including measurements of the underlying-event, …


Final Rmap Park Soil Sampling Field Sampling Plan (Fsp) Submittal #7 [Covering Gold Hill Lutheran Church, Peoples Park, Sioux Park, Charlie Judd Park, Emma Park, Mandan Park, And Walkerville Park (Daly And Dunn)], Pioneer Technical Services, Inc. May 2023

Final Rmap Park Soil Sampling Field Sampling Plan (Fsp) Submittal #7 [Covering Gold Hill Lutheran Church, Peoples Park, Sioux Park, Charlie Judd Park, Emma Park, Mandan Park, And Walkerville Park (Daly And Dunn)], Pioneer Technical Services, Inc.

Silver Bow Creek/Butte Area Superfund Site

No abstract provided.


Evaluation Of Temperature-Index And Energy-Balance Snow Models For Hydrological Applications In Operational Water Supply Forecasts, Tian Gan, David G. Tarboton, Tseganeh Z. Gichamo May 2023

Evaluation Of Temperature-Index And Energy-Balance Snow Models For Hydrological Applications In Operational Water Supply Forecasts, Tian Gan, David G. Tarboton, Tseganeh Z. Gichamo

Civil and Environmental Engineering Faculty Publications

In the western United States, snow accumulation, storage, and ablation affect seasonal runoff. Thus, the prediction of snowmelt is essential to improve the reliability of water supply forecasts to guide water allocation and operational decisions. The current method used at the Colorado Basin River Forecast Center (CBRFC) couples the SNOW-17 temperature index snow model and the Sacramento Soil Moisture Accounting (SAC-SMA) runoff model in a lumped approach. Limitations in parameter transferability and calibration requirements for changing conditions with the temperature-index model motivated this research, in which new avenues were investigated to assess and prototype the application of an energy-balance snow …


A Hörmander–Fock Space, Daniel Alpay, Fabrizio Colombo, Kamal Diki, Irene Sabadini, Daniele C. Struppa May 2023

A Hörmander–Fock Space, Daniel Alpay, Fabrizio Colombo, Kamal Diki, Irene Sabadini, Daniele C. Struppa

Mathematics, Physics, and Computer Science Faculty Articles and Research

In a recent paper we used a basic decomposition property of polyanalytic functions of order 2 in one complex variable to characterize solutions of the classical ∂-problem for given analytic and polyanalytic data. Our approach suggested the study of a special reproducing kernel Hilbert space that we call the Hörmander-Fock space that will be further investigated in this paper. The main properties of this space are encoded in a specific moment sequence denoted by η= (ηn)n≥0 leading to a special entire function E(z) that is used to express the kernel function of the Hörmander-Fock space. We …


Implementing A Functional Logic Programming Language Via The Fair Scheme, Andrew Michael Jost May 2023

Implementing A Functional Logic Programming Language Via The Fair Scheme, Andrew Michael Jost

Dissertations and Theses

This document presents a new compiler for the Functional Logic programming language Curry based on a novel pull-tabbing evaluation strategy called the Fair Scheme. A simple version of the Fair Scheme is proven sound, complete, and optimal. An elaborated version is also developed, which supports narrowing computations and other features of Curry, such as constraint programming, equational constraints, and set functions.

The Fair Scheme is used to develop a new Curry system called Sprite, a high-quality, performant implementation whose aims are to promote practical uses of Curry and to serve as a laboratory for further research. An important aspect of …


A Gridded Co2 Emissions Inventory For Portland, Or, James Eckhardt Powell May 2023

A Gridded Co2 Emissions Inventory For Portland, Or, James Eckhardt Powell

Dissertations and Theses

Here we develop a new high resolution inventory of CO2 emissions for the three Oregon counties which comprise the bulk of the City of Portland, Oregon, USA. Locally curated and long-running data collection efforts for on-road traffic activity and emission rates are used to model on-road emissions, and a new survey of the area's natural gas network informs the building energy model. The inventory estimates total emissions of CO2 for each hour of the year 2018 in the on-road, residential, and commercial building sectors at 1 km2 resolution. The onroad inventory compares to within 3% with an …


Effective Non-Hermiticity And Topology In Markovian Quadratic Bosonic Dynamics, Vincent Paul Flynn May 2023

Effective Non-Hermiticity And Topology In Markovian Quadratic Bosonic Dynamics, Vincent Paul Flynn

Dartmouth College Ph.D Dissertations

Recently, there has been an explosion of interest in re-imagining many-body quantum phenomena beyond equilibrium. One such effort has extended the symmetry-protected topological (SPT) phase classification of non-interacting fermions to driven and dissipative settings, uncovering novel topological phenomena that are not known to exist in equilibrium which may have wide-ranging applications in quantum science. Similar physics in non-interacting bosonic systems has remained elusive. Even at equilibrium, an "effective non-Hermiticity" intrinsic to bosonic Hamiltonians poses theoretical challenges. While this non-Hermiticity has been acknowledged, its implications have not been explored in-depth. Beyond this dynamical peculiarity, major roadblocks have arisen in the search …


Expressive Marks: Art In The Age Of Augmented Reality, Carson G. Levine May 2023

Expressive Marks: Art In The Age Of Augmented Reality, Carson G. Levine

Dartmouth College Master’s Theses

Augmented reality (AR) and non-fungible tokens (NFTs) introduce new considerations for the long-standing debate of what it means for digital art to be “real.” However, the ability to create AR experiences is limited to those who are technically skilled or who can afford to consult someone else. This paper addresses the need for an accessible tool that enables artists of all technical backgrounds to expressively create marks in AR. The solution includes a mobile application called CrayonAR. The system was designed to be modular, minimal, and physically engaging, and was developed in Unity using ARFoundation and Firebase Storage and Realtime …


Visible Light Photoacid Generator Catalyzed Michael Additions & In-Situ Photoredox Generated Carbocation Catalysis, Zena M. Salem May 2023

Visible Light Photoacid Generator Catalyzed Michael Additions & In-Situ Photoredox Generated Carbocation Catalysis, Zena M. Salem

Seton Hall University Dissertations and Theses (ETDs)

Proton transfer is essential in many natural and chemical processes, and photoacids that undergo proton dissociation or generation upon photoirradiation can be beneficial for use in acid-sensitive reactions. This work describes the use of photoacid generators (PAGs) as tools for organic synthesis, generating strong acids upon light absorption catalyzing Michael addition reactions. Specifically, visible-light-induced PAGs were used to facilitate the 1,4-conjugate addition between indoles and vinyl ketones. Furthermore, carbocations have gained attention as Lewis acid catalysts in a variety of reactions providing good selectivity and yields. We also demonstrate the viability of in-situ photoredox-generated carbocation catalysis in the context of …


Artificial Intelligence In Neuroradiology: A Scoping Review Of Some Ethical Challenges, Pegah Khosravi, Mark Schweitzer May 2023

Artificial Intelligence In Neuroradiology: A Scoping Review Of Some Ethical Challenges, Pegah Khosravi, Mark Schweitzer

Publications and Research

Artificial intelligence (AI) has great potential to increase accuracy and efficiency in many aspects of neuroradiology. It provides substantial opportunities for insights into brain pathophysiology, developing models to determine treatment decisions, and improving current prognostication as well as diagnostic algorithms. Concurrently, the autonomous use of AI models introduces ethical challenges regarding the scope of informed consent, risks associated with data privacy and protection, potential database biases, as well as responsibility and liability that might potentially arise. In this manuscript, we will first provide a brief overview of AI methods used in neuroradiology and segue into key methodological and ethical challenges. …


An Assistive Interface For Displaying Novice's Code History, Ruiwei Xiao May 2023

An Assistive Interface For Displaying Novice's Code History, Ruiwei Xiao

McKelvey School of Engineering Theses & Dissertations

As Teaching Assistant (TA) programs grow in number and size in introductory CS courses, TAs play a significant role in novice programmers' experience and contribute to their success. However, many TAs are also relative beginners themselves and thus have limited experience in programming and teaching. Thus the effectiveness and consistency of their guidance can vary significantly. To improve interaction quality and assist TAs in providing better support, we examine the difficulties encountered by inexperienced TAs in previous literature and then identify the potential for the high cognitive load as an unaddressed difficulty that may prevent new TAs from initiating effective …


On Specifications Of Positive Data Models With Effectively Separable Kernels Of Algorithmic Representations, Nodira R. Karimova May 2023

On Specifications Of Positive Data Models With Effectively Separable Kernels Of Algorithmic Representations, Nodira R. Karimova

Bulletin of National University of Uzbekistan: Mathematics and Natural Sciences

It is established that any effectively separable multi-sorted positively representable model with an effectively separable representation kernel has an enrichment that is the only (up to isomorphism) model constructed from constants for a suitable computably enumerable set of sentences.


Draft Final Bpsou Unreclaimed Sites Ur-06 Temporary Best Management Practice Work Plan, Pioneer Technical Services, Inc. May 2023

Draft Final Bpsou Unreclaimed Sites Ur-06 Temporary Best Management Practice Work Plan, Pioneer Technical Services, Inc.

Silver Bow Creek/Butte Area Superfund Site

No abstract provided.


Butte Reduction Works (Brw) Smelter Area Mine Waste Remediation And Contaminated Groundwater Hydraulic Control Site Quality Assurance Project Plan (Qapp) For Microbial Analysis And Biotreatability; Request For Change Brw-2023-02, Pioneer Technical Services, Inc. May 2023

Butte Reduction Works (Brw) Smelter Area Mine Waste Remediation And Contaminated Groundwater Hydraulic Control Site Quality Assurance Project Plan (Qapp) For Microbial Analysis And Biotreatability; Request For Change Brw-2023-02, Pioneer Technical Services, Inc.

Silver Bow Creek/Butte Area Superfund Site

No abstract provided.


A Stochastic Search For Intermittent Gravitational-Wave Backgrounds, Jessica Lawrence, Kevin Turbang, Andrew Matas, Arianna I. Renzini, Nick Van Remortel, Joseph D. Romano May 2023

A Stochastic Search For Intermittent Gravitational-Wave Backgrounds, Jessica Lawrence, Kevin Turbang, Andrew Matas, Arianna I. Renzini, Nick Van Remortel, Joseph D. Romano

Physics and Astronomy Faculty Publications and Presentations

A likely source of a gravitational-wave background (GWB) in the frequency band of the Advanced LIGO, Virgo, and KAGRA detectors is the superposition of signals from the population of unresolvable stellar-mass binary-black-hole (BBH) mergers throughout the Universe. Since the duration of a BBH merger in band (similar to 1 s) is much shorter than the expected separation between neighboring mergers (similar to 103 s), the observed signal will be "popcornlike" or intermittent with duty cycles of order 10-3. However, the standard cross-correlation search for stochastic GWBs currently performed by the LIGO-Virgo-KAGRA Collaboration is based on a continuous-Gaussian signal model, which …


Development And Validation Of A Uplc-Ms/Ms Method To Investigate The Plasma Pharmacokinetics Of A KCa2.2/KCa2.3 Positive Allosteric Modulator In Mice, Mohammad Asikur Rahman, Devaraj Venkatapura Chandrashekar, Young-Woo Nam, Basir Syed, David Salehi, Hamidreza Montazeri Aliabadi, Miao Zhang, Reza Mehvar May 2023

Development And Validation Of A Uplc-Ms/Ms Method To Investigate The Plasma Pharmacokinetics Of A KCa2.2/KCa2.3 Positive Allosteric Modulator In Mice, Mohammad Asikur Rahman, Devaraj Venkatapura Chandrashekar, Young-Woo Nam, Basir Syed, David Salehi, Hamidreza Montazeri Aliabadi, Miao Zhang, Reza Mehvar

Pharmacy Faculty Articles and Research

Rationale

There is currently no treatment for spinocerebellar ataxias (SCAs), which are a group of genetic disorders that often cause a lack of coordination, difficulty walking, slurred speech, tremors, and eventually death. Activation of KCa2.2/KCa2.3 channels reportedly exerts beneficial effects in SCAs. Here, we report the development and validation of an analytical method for quantitating a recently-developed positive allosteric modulator of KCa2.2/KCa2.3 channels (compound 2q) in mouse plasma.

Methods

Mouse plasma samples (10 μL) containing various concentrations of 2q were subjected to protein precipitation in the presence of a structurally similar internal …


Downstream Gradients In Unit Stream Power Influence Log Jam Location And Process Domain, Eliza H. Malakoff May 2023

Downstream Gradients In Unit Stream Power Influence Log Jam Location And Process Domain, Eliza H. Malakoff

Dartmouth College Master’s Theses

Growing calls for the use of natural materials and processes to meet management goals have positioned artificial log jams as a compelling alternative to hard engineering instream and floodplain habitat. Deep uncertainties remain, however, about where and how wood should be placed to best mimic natural river processes. In this study, I test whether at-a-point or downstream gradients in unit stream power, an estimate of a river’s ability to do work, exert control over where and how log jams form. Using field observations of 360 log jams in New Hampshire and Vermont and an additional 320 previously published locations of …


Feature Selection From Clinical Surveys Using Semantic Textual Similarity, Benjamin Warner May 2023

Feature Selection From Clinical Surveys Using Semantic Textual Similarity, Benjamin Warner

McKelvey School of Engineering Theses & Dissertations

Survey data collected from human subjects can contain a high number of features while having a comparatively low quantity of examples. Machine learning models that attempt to predict outcomes from survey data under these conditions can overfit and result in poor generalizability. One remedy to this issue is feature selection, which attempts to select an optimal subset of features to learn upon. A relatively unexplored source of information in the feature selection process is the usage of textual names of features, which may be semantically indicative of which features are relevant to a target outcome. The relationships between feature names …


Photophysical And Photochemical Processes In Small Molecules And Materials For Solar Energy Conversion, Ethan Lambert May 2023

Photophysical And Photochemical Processes In Small Molecules And Materials For Solar Energy Conversion, Ethan Lambert

Honors Theses

The work covered in this thesis all falls under the theme of photophysical processes after light and matter interact. Those of primary interest are Raman scattering induced vibrations and excited state dynamics probed by transient absorption spectroscopy. Small molecules are studied with Raman spectroscopy and computational chemistry. These studies unearth the shifts in vibrational frequency as a function of charge transfer or receipt and how a quantitative assay of natural orbital populations and delocalization can offer both the nature and magnitude of this charge transfer. Further, a method is presented that builds upon previous work within the academic family tree; …


Photocatalyzed Hydrogen Evolution Using Nickel-Bound Metallothionein Protein, Windfield Swetman May 2023

Photocatalyzed Hydrogen Evolution Using Nickel-Bound Metallothionein Protein, Windfield Swetman

Honors Theses

The continued burning of fossil fuels is not only a cause of increasing deterioration of the environment but also a financially unsustainable source of energy. Advances in energy production must be investigated to avoid the long-term effects of this current main source of energy. One of the avenues being explored is the use of metalloenzymes to catalyze hydrogen evolution via water splitting that occurs during the reductive half of artificial photosynthesis. Metalloenzyme catalysts with a single Ni(Cys)4 active site have been previously studied, and this study explores the possibility of increasing hydrogen production by using metalloenzyme catalysts with multiple …


A Study Of Data/Monte Carlo Agreement In Charmed Baryon Decays At Belle Ii, Kaitlyn Thurmond May 2023

A Study Of Data/Monte Carlo Agreement In Charmed Baryon Decays At Belle Ii, Kaitlyn Thurmond

Honors Theses

The Belle II experiment at the SuperKEKB electron-positron accelerator facility in Tsukuba, Japan has a primary goal of searching for new physics beyond the Standard Model of particle physics. Extremely precise measurements of particle decays will be compared with Standard Model predictions in order to expose the presence of new particles and interactions. These measurements are prepared using simulated samples to avoid potential biases when studying the data. The Belle II collaboration produces two types of simulated samples for this purpose. One is produced with consistent calibration payloads and another with payloads calibrated as a function of data taking. This …


Investigating Reactivity Of Artificial Copper Peptides With Small Molecules, Allyson Bryant May 2023

Investigating Reactivity Of Artificial Copper Peptides With Small Molecules, Allyson Bryant

Honors Theses

The design of artificial enzymes has been a topic of significant interest in the field of biochemistry, as they can provide new opportunities for catalytic processes and drug development. De novo protein design has emerged as a promising approach to create such enzymes, and the study of metalloproteins, particularly copper-binding peptides, has become a focus of this research. This thesis investigates the reactivity of a mutated copper-binding peptide, I5A-3SCC, with oxygen and its implications in the development of artificial enzymes.

The parent peptide, 3SCC, was mutated by replacing Isoleucine residues with smaller Alanine side chains, which was hypothesized to enhance …


Aging An Ancient Maya Population From Actuncan, Belize Using Dental X-Rays, Kaitlyn Nicole Cash May 2023

Aging An Ancient Maya Population From Actuncan, Belize Using Dental X-Rays, Kaitlyn Nicole Cash

Honors Theses

My goal is to determine an accurate age at death estimation of an ancient Maya population from the archaeological site of Actuncan, Belize. This was done by measuring the lengths of the coronal pulp cavities in the individuals’ teeth. I used X-Ray images to measure the coronal pulp cavities of the teeth and estimated age using multiple regression formulae for premolars, molars, and incisors to make age estimations. The formulae came from two studies, Ikeda et al. (1985) and Drusini (2008), that form the basis of my research. Ikeda et al. (1985) was the first to use this aging method, …