Digital Commons Network^™

Constitutional Law: Blockchain’S Challenge For The Fourth Amendment, Paul Belonick

The Judges' Book

No abstract provided.

Chancery Court Questions Whether Nominally Designated "Independent" Directors Satisfied Requirements Of Stockholders Agreement, Robert S. Reder, Eunice Lim

Vanderbilt Law Review

No abstract provided.

Towards Formally Verified Compilation Of Tag-Based Policy Enforcement, Chr Chhak, Andrew Tolmach, Sean Anderson

Computer Science Faculty Publications and Presentations

Hardware-assisted reference monitoring is receiving increasing attention as a way to improve the security of existing software. One example is the PIPE architecture extension, which attaches metadata tags to register and memory values and executes tag-based rules at each machine instruction to enforce a software-defined security policy. To use PIPE effectively, engineers should be able to write security policies in terms of source-level concepts like functions, local variables, and structured control operators, which are not visible at machine level. It is the job of the compiler to generate PIPE-aware machine code that enforces these source-level policies. The compiler thus becomes …

Our Imperial Federal Courts, Matthew Steilen

Vanderbilt Law Review

No abstract provided.

Poised For Change: University Students Are Positively Disposed Toward Food Waste Diversion And Decrease Individual Food Waste After Programming, Manar Arica Alattar, Jennifer L. Morse

Environmental Science and Management Faculty Publications and Presentations

Eaters (consumers of food) are responsible for 60% of waste along the food cycle in developed countries. Programs that target individual and household food waste behavior change are essential to addressing such waste. School cafeterias worldwide offer an opportune microcosm in which to educate on food and nutrition skills and change related behavior. No Scrap Left Behind, a cafeteria food waste diversion program, was developed, piloted, and assessed based on measures of both direct and indirect food waste behavior, and attitudes, knowledge, and emotions related to food waste. Participants had positive attitudes towards food waste reduction, engaged in food waste …

Exclusion Statistics For Particles With A Discrete Spectrum, Stéphane Ouvry, Alexios P. Polychronakos

Publications and Research

We formulate and study the microscopic statistical mechanics of systems of particles with exclusion statistics in a discrete one-body spectrum. The statistical mechanics of these systems can be expressed in terms of effective single-level grand partition functions obeying a generalization of the standard thermodynamic exclusion statistics equation of state. We derive explicit expressions for the thermodynamic potential in terms of microscopic cluster coefficients and show that the mean occupation numbers of levels satisfy a nesting relation involving a number of adjacent levels determined by the exclusion parameter. We apply the formalism to the harmonic Calogero model and point out a …

Wavefront-Selective Fano Resonant Metasurface, Adam C. Overvig, Andrea Alù

Publications and Research

Fano resonances are conventionally understood as sharp spectral features with selectivity in the momentum-frequency domain, implying that they can be excited only by plane waves with specific frequencies and incident angles. We demonstrate that Fano resonances can be made generally selective in the space-frequency domain. They can be tailored to resonate only when excited by a frequency, polarization, and wavefront of choice. This generalization reveals that Fano systems are characterized by eigenwaves that scatter to their time-reversed image upon reflection. Although in conventional Fano systems this trivially occurs for normally incident plane waves, we show that, in general, the selected …

Calabi-Yau Products: Graded Quivers For General Toric Calabi-Yaus, Sebastián Franco, Azeem Hasan

Publications and Research

The open string sector of the topological B-model on CY (m + 2)-folds is described by m-graded quivers with superpotentials. This correspondence generalizes the connection between CY (m + 2)-folds and gauge theories on the worldvolume of D(5 − 2m)-branes for m = 0, . . . , 3 to arbitrary m. In this paper we introduce the Calabi-Yau product, a new algorithm that starting from the known quiver theories for a pair of toric CY_m+2 and CY_n+2 produces the quiver theory for a related CY_{m+n+3 …}

Dimers, Orientifolds And Anomalies, Riccardo Argurio, Matteo Bertolini, Sebastían Franco, Eduardo Garcia-Valdecasas, Shani Meynet, Antoine Pasternak, Valdo Tatitscheff

Publications and Research

We study 4d N = 1 gauge theories engineered via D-branes at orientifolds of toric singularities, where gauge anomalies are cancelled without the introduction of non-compact flavor branes. Using dimer model techniques, we derive geometric criteria for establishing whether a given singularity can admit anomaly-free D-brane configurations purely based on its toric data and the type of orientifold projection. Our results therefore extend the dictionary between geometric properties of singularities and physical properties of the corresponding gauge theories.

Dimers, Orientifolds And Stability Of Supersymmetry Breaking Vacua, Riccardo Argurio, Matteo Bertolini, Sebastían Franco, Eduardo García-Valdecasas, Shani Meynet, Antoine Pasternak, Valdo Tatitscheff

Publications and Research

We study (orientifolded) toric Calabi-Yau singularities in search for D-brane configurations which lead to dynamical supersymmetry breaking at low energy. By exploiting dimer techniques we are able to determine that while most realizations lead to a Coulomb branch instability, a rather specific construction admits a fully stable supersymmetry breaking vacuum. We describe the geometric structure that a singularity should have in order to host such a construction, and present its simplest example, the Octagon.

Light-Ray Moments As Endpoint Contributions To Modular Hamiltonians, Daniel Kabat, Gilad Lifschytz, Phuc Nguyen, Debajyoti Sarkar

Publications and Research

We consider excited states in a CFT, obtained by applying a weak unitary perturbation to the vacuum. The perturbation is generated by the integral of a local operator J⁽ⁿ⁾ of modular weight n over a spacelike surface passing through x = 0. For |n| ≥ 2 the modular Hamiltonian associated with a division of space at x = 0 picks up an endpoint contribution, sensitive to the details of the perturbation (including the shape of the spacelike surface) at x = 0. The endpoint contribution is a sum of light-ray moments of the perturbing operator …

Jazz Colors: Pigment Identification In The Gouaches Used By Henri Matisse, Ana Martins, Anne Catherine Prud’Hom, Maroussia Duranton, Abed Haddad, Celine Daher, Anne Genachte-Le Bail, Tiffany Tang

Publications and Research

Jazz, the illustrated book by Henri Matisse, is a testament to the vitality of the artist in the last decade of his career. The book consists of twenty illustrations reproduced in 370 copies using a stencil-based printing technique and the same Linel gouaches the artist had used for the original maquettes. This study reports on the comprehensive analysis carried out to identify the pigments in the gouaches used in Jazz by transmitted and reflectance infrared, Raman, SERS, and X-ray fluorescence spectroscopies, and describes the lightfastness of these gouaches as evaluated by microfaedometry. This study also highlights the necessity of …

Optimization Of Coverage Ratios For Basis And Freight Trading Portfolios, Adam Joseph Kroll

Agribusiness and Applied Economics

Changing commodity prices create opportunities for traders to profit or experience substantial losses if risk is not managed. Extensive research has been presented regarding optimal hedging strategies using futures markets to mitigate price risk of holding a physical commodity, but the literature has not introduced a method for optimizing basis or rail coverage ratios. This study introduces coverage ratios to manage basis and transportation risk. Coverage ratios are optimized for a portfolio of basis and rail positions consistent with expected utility theory using Monte Carlo simulation at various risk aversion levels. The results indicated that as risk aversion increased, optimal …

Global Impact Of The U.S.-China Trade War In Agricultural Sector, Enoch Adom

Agribusiness and Applied Economics

This thesis examined the impact of the U.S-China trade war on the global, U.S, and China’s agricultural exports while considering the competing suppliers’ effect using a highly disaggregated HS 6-digit trade flow data in the structural gravity model. The empirical results indicate that the trade war caused about 8.6% and 17% reduction in U.S and China’s agricultural exports, respectively. However, global agricultural export was not negatively impacted during the trade war. Finally, the results also showed that tariff increases by U.S caused an increased in U.S competing suppliers’ exports to China. Similarly, China’s retaliatory tariffs caused an increase in China’s …

The United States And Brazil - Spatial And Logistical Interdependence For Soybean Shipments To China, Gwen Marie Scheresky

Agribusiness and Applied Economics

Analyzing the United States/Brazil competition for market share of Chinese soybean imports requires a detailed, stochastic approach. Using data from 2013 to 2019, this thesis attempts to model and explain the change in market share for each producing country as different variables fluctuate or enter the equation. Using five origins in each country, the PNW, USG, Santos, Paranaguá, and the northern arc of ports in Brazil, various transportation routes from origin to port, congestion and quality metrics, and ocean freight, a least-cost optimized Monte Carlo simulation is performed using time-series forecasting distributions for monthly variables. A distribution of outcomes for …

The Case For A Long-Lived And Robust Yellowstone Hotspot, Victor E. Camp, Ray E. Wells

Geology Faculty Publications and Presentations

The Yellowstone hotspot is recognized as a whole-mantle plume with a history that extends to at least 56 Ma, as recorded by offshore volcanism on the Siletzia oceanic plateau. Siletzia accreted onto the North American plate at 51–49 Ma, followed by repositioning of the Farallon trench west of Siletzia from 48 to 45 Ma. North America overrode the hotspot, and it transitioned from the Farallon plate to the North American plate from 42 to 34 Ma. Since that time, it has been genetically associated with a series of aligned volcanic provinces associated with ageprogressive events that include Oligocene high-K calc-alkaline …

Toward An Integrative Geological And Geophysical View Of Cascadia Subduction Zone Earthquakes, Maureen A.L. Walton, Lydia M. Staisch, Tina Dura, Jessie K. Pearl, Brian Sherrod, Joan Gomberg, Simon Engelhart, Ray E. Wells, Multiple Additional Authors

Geology Faculty Publications and Presentations

The Cascadia subduction zone (CSZ) is an exceptional geologic environment for recording evidence of land-level changes, tsunamis, and ground motion that reveals at least 19 great megathrust earthquakes over the past 10 kyr. Such earthquakes are among the most impactful natural hazards on Earth, transcend national boundaries, and can have global impact.Reducing the societal impacts of future events in the US Pacific Northwest and coastal British Columbia, Canada, requires improved scientific understanding of megathrust earthquake rupture, recurrence, and corresponding hazards. Despite substantial knowledge gained from decades of research, large uncertainties remain about the characteristics and frequencies of past CSZ earthquakes. …

Ethanol Policy, Commodity Revenue, And Import Quantity Demand: The United States And Brazil, Bree Lyn Diffely

Agribusiness and Applied Economics

Brazil and the United States have been major players in the ethanol industry for over a decade. Both countries have a strong policy backing to push the production and use of the renewable fuel while other parts of the world seem to fall short in comparison. These two nations can be used to determine how an ethanol policy affects ethanol producing commodities as well as the factors that drive import quantity demanded based on export statistics.

Business Risk, Financial Risk, And Liquidity Management On U.S. Farms - Evidence From Selected States, Emin Allahverdiyev

Agribusiness and Applied Economics

Risk management is pivotal to agribusiness decision-making, and researchers have developed various models to disentangle factors underlying farmers’ risk decisions. This thesis argues that an appropriate model should consider farmers’ leverage decisions altogether with liquidity decisions given that liquidity is another major constraint facing farm businesses. We incorporate current ratio into the classical risk balancing model. Our theoretical derivations generate two propositions: (1) an increase in business risk will cause current assets to increase, and (2) an increase in the expected return to assets will cause current assets to decrease. Using five income categories and three panel data models, regression …

Ex-Ante Temporal Optimization In Soybean Origination: An Overdetermined Approach Through Deep Learning, Noah Joseph Carlson

Agribusiness and Applied Economics

Digitization is influencing commodity trading and agricultural markets and as they transition towards extreme liquidity, agribusiness risk exposures increase, and traditional competitive advantages diminish. In commodity origination, logistics and destination basis comprise the most volatile and determinant influences of margin. To capture a consistently higher margin and represent narrowed interior basis, agribusiness firms must manage these risks by optimizing transformations. To accomplish this, ex-ante decision-making is often necessary as forward price clairvoyance is not always prevalent, is risky, or contains premium. Modeling this spatial equilibrium is difficult through traditional reductionist and essentialist application as the overdetermined and convoluted system presents …

The Interface And Instrumentality Of Eurorack Modular Synthesis, Eliot Bates

Publications and Research

In this essay, I will examine a couple of aspects of hardware modular synthesizers which, despite not being a “new” morphological form (most commercially sold synthesizers from the 1960s through the early 1970s were modular), experienced an extremely unlikely expansion of interest and activity in the mid-1990s. With a contemporary modular synth, users buy a powered rack that holds modules specific to one of several competing formats. For the two most widely adopted formats, Eurorack (sometimes called 3U in reference to the height of modules, or Doepfer A-100 after the first branded system to adopt this panel height) and MOTM/MU …

Toward A Next Generation Particle Precipitation Model: Mesoscale Prediction Through Machine Learning (A Case Study And Framework For Progress), Ryan C. Mcgranaghan, Jack Ziegler, Téo Bloch, Spencer Hatch, Enrico Camporeale, Kristina A. Lynch, Mathew Owens, Jesper Gjerloev, Binzheng Zhang, Susan Skone

Dartmouth Scholarship

We advance the modeling capability of electron particle precipitation from the magnetosphere to the ionosphere through a new database and use of machine learning (ML) tools to gain utility from those data. We have compiled, curated, analyzed, and made available a new and more capable database of particle precipitation data that includes 51 satellite years of Defense Meteorological Satellite Program (DMSP) observations temporally aligned with solar wind and geomagnetic activity data. The new total electron energy flux particle precipitation nowcast model, a neural network called PrecipNet, takes advantage of increased expressive power afforded by ML approaches to appropriately utilize diverse …

Small-Scale Dynamic Aurora, Ryuho Kataoka, Christopher C. Chaston, David Knudsen, Kristina A. Lynch, Robert L. Lysak, Yan Song, Robert Rankin, Kiyoka Murase, Takeshi Sakanoi, Joshua Semeter, Tomo-Hiko Watanabe, Daniel Whiter

Dartmouth Scholarship

Small-scale dynamic auroras have spatial scales of a few km or less, and temporal scales of a few seconds or less, which visualize the complex interplay among charged particles, Alfvén waves, and plasma instabilities working in the magnetosphere-ionosphere coupled regions. We summarize the observed properties of flickering auroras, vortex motions, and filamentary structures. We also summarize the development of fundamental theories, such as dispersive Alfvén waves (DAWs), plasma instabilities in the auroral acceleration region, ionospheric feedback instabilities (IFI), and the ionospheric Alfvén resonator (IAR).

Examining The Auroral Ionosphere In Three Dimensions Using Reconstructed 2d Maps Of Auroral Data To Drive The 3d Gemini Model, Robert Clayton, Meghan Burleigh, Kristina A. Lynch, Matt Zettergren, Tucker Evans, Guy Grubbs, Donald L. Hampton, David Hysell, Stephen Kaeppler, Marc Lessard, Robert Mitchell, Ashton Reimer, T. Maximillian Roberts, Marilia Samara, Roger Varney

Dartmouth Scholarship

We use the Geospace Environment Model of Ion-Neutral Interactions (GEMINI) to create three-dimensional, time-dependent simulations of auroral ionospheric parameters in the localized, several 100 km region surrounding auroral arcs observed during a winter 2017 sounding rocket campaign, resolving three-dimensional features of fine-scale (km) flow structures in the vicinity of an auroral arc. The three-dimensional calculations of GEMINI allow (with sufficient driving data) auroral current closure to be investigated without idealizing assumptions of sheet-like structures or height integrated ionospheres. Datamaps for two nearly sheet-like arcs are reconstructed from replications of the Isinglass sounding rocket campaign data, and combined with camera-based particle …

Implementing High-Throughput Phenotyping At The Ndsu Dry Bean (Phaseolus Vulgaris L.) Breeding Program Using Unmanned Aerial Systems, Diego Jose Gris

Agribusiness and Biosystems Engineering

Plant breeding has led to considerable yield gains to several crops. However, it alone might not be able to keep up with the growing demand for food. In this study, data extracted from UAS-collected RGB and multispectral images were assessed on their ability to estimate four agronomic traits in three market classes of dry beans in a breeding program. The results showed that (i) seed yield, 100-seed weight, stem diameter and days to flowering can be estimated within the same market class with variable accuracy; (ii) aggregating data from several flights yielded better results than using a single flight; (iii) …

Understanding The Relationship Between Weather Variables, Dry Matter Intake, And Average Daily Gain Of Beef Cattle, Mustapha Yusuf

Animal Sciences

The current National Academies of Sciences, Engineering and Medicine (NASEM) dry matter intake (DMI) prediction models are inadequate for DMI prediction of beef cattle in the Northern Great Plains. Four studies were conducted to account for additional variation in DMI and average daily gain (ADG) caused by weather variables. Experiment 1 and 2 had 13,895 steer-weeks observations, experiment 3 had 13,739 steer-weeks observations, and experiment 4 had 2,161 cow-weeks observations, respectively. Experiment 1 examined the influence of ambient temperature and solar radiation on DMI of beef steers. In experiment 2, 3, and 4, we examined the influence of ambient temperature, …

Ancestral Breed Grouping For Improving Animal Modeling In Admixed Populations And Its Use In Leptin (Genetic And Hormone) Association Studies With Performance Traits In Commercial Beef Cow Herd, Nayan Bhowmik

Animal Sciences

The first study investigated American Aberdeen (AD) cattle's genetic structure and its genetic relationships with five American taurine beef breeds and the genetic population structure of a related admixed cattle herd for improved statistical modeling. The last two studies investigated the role of leptin (LEP) c.73C>T polymorphism, leptin diplotype (LEPD), and leptin hormone (LEPH) concentration on reproductive, growth, size, feeding, and carcass ultrasound traits in beef cows and heifers. High levels of polymorphism were observed in admixed, Red Angus, and Gelbvieh (GV) populations. The lowest level of polymorphism was found in AD followed by undetermined parentage. Pairwise fixation index …

Occam Software (And Manual) For Reconstructability Analysis, Martin Zwick, Kenneth Willett, Joe Fusion, Heather Alexander

Complex Systems Faculty Publications and Presentations

OCCAM is a Discrete Multivariate Modeling (DMM) tool based on the methodology of Reconstructability Analysis (RA). As an acronym it stands for Organizational Complexity Computation and Modeling, and the name is also a reference (with a non-standard spelling) to Ockham’s Razor. The principal programmers of its current version have been Kenneth Willett, Joe Fusion, and Heather Alexander. Ken Willett totally rewrote earlier versions of OCCAM. His version was originally called “OCCAM3” to distinguish it from these earlier OCCAM incarnations; the “3” has finally been dropped.

OCCAM’s typical use is to analyze data involving a large number of discrete variables, but …

Reconstructability Analysis Of The Predictors Of Physical Functioning Status In Older Americans By Race And Ethnicity, Amanuel Melekin, Martin Zwick

Complex Systems Faculty Publications and Presentations

This paper demonstrates the use of reconstructability analysis to examine race/ethnic differences in physical functioning status among older Americans. Reconstructability analysis is an information theory and graph theory method which has been successfully used in multivariate data modeling. The health and retirement study data from 2004 are used for this demonstration. Out of eighteen independent variables included, seven variables appeared in the best models selected. Uncertainty reductions in physical functioning status were substantial across the models but the magnitudes and predictive variables varied slightly by race/ethnicity. Examination of the model probability distributions indicated that composite independent variable states of overlapping …

Pdxscholar Annual Report 2020, Karen Bjork, Sherry Buchanan, David Coate, Bertrand Robinson, Stacey Schlatter

Library Faculty and Staff Publications and Presentations

This report details the tenth year of operation for PDXScholar, Portland State University's institutional repository. The report covers the period between January 1, 2020 and December 31, 2020.

The 2020 report highlights the exponential growth of PDXScholar with almost 2.1 million (2,094,796) full text downloads. This is an increase of approximately 800,000 downloads from 2019, representing a 62% increase.

The report also focuses on our work to bring online new collections and to highlight research impacting our communities, academics, and personal lives.