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Integrating Oceanographic Research Into High School Curricula: Achieving Broader Impacts Through Systems Education Experiences Modules, Monica V. Orellana, Claudia Ludwig, Anne W. Thompson, Nitin S. Baliga Jan 2020

Integrating Oceanographic Research Into High School Curricula: Achieving Broader Impacts Through Systems Education Experiences Modules, Monica V. Orellana, Claudia Ludwig, Anne W. Thompson, Nitin S. Baliga

Biology Faculty Publications and Presentations

We describe a framework for incorporating cross-disciplinary oceanographic research into high school curriculum modules and discuss how this framework could be adopted broadly by ocean scientists to build cohesive broader impacts programs nested within individual oceanographic research programs.


Daily Stream Samples Reveal Highly Complex Pesticide Occurrence And Potential Toxicity To Aquatic Life, Julia E. Norman, Barbara J. Mahler, Lisa H. Nowell, Peter C. Van Metre, Mark W. Sandstrom, Mark A. Corbin, Yaorong Qian, James F. Pankow, Wentai Luo, Nicholas B. Fitzgerald, Multiple Additional Authors Jan 2020

Daily Stream Samples Reveal Highly Complex Pesticide Occurrence And Potential Toxicity To Aquatic Life, Julia E. Norman, Barbara J. Mahler, Lisa H. Nowell, Peter C. Van Metre, Mark W. Sandstrom, Mark A. Corbin, Yaorong Qian, James F. Pankow, Wentai Luo, Nicholas B. Fitzgerald, Multiple Additional Authors

Chemistry Faculty Publications and Presentations

Transient, acutely toxic concentrations of pesticides in streams can go undetected by fixed-interval sampling programs. Here we compare temporal patterns in occurrence of current-use pesticides in daily composite samples to those in weekly composite and weekly discrete samples of surface water from 14 small stream sites. Samples were collected over 10–14 weeks at 7 stream sites in each of the Midwestern and Southeastern United States. Samples were analyzed for over 200 pesticides and degradates by direct aqueous injection liquid chromatography with tandem mass spectrometry. Nearly 2 and 3 times as many unique pesticides were detected in daily samples as in …


Synthesis Of Radioluminescent Caf2:Ln Core, Mesoporous Silica Shell Nanoparticles For Use In X-Ray Based Theranostics, Hayden Winter, Megan J. Neufeld, Lydia Makotamo, Conroy Sun, Andrea M. Goforth Jan 2020

Synthesis Of Radioluminescent Caf2:Ln Core, Mesoporous Silica Shell Nanoparticles For Use In X-Ray Based Theranostics, Hayden Winter, Megan J. Neufeld, Lydia Makotamo, Conroy Sun, Andrea M. Goforth

Chemistry Faculty Publications and Presentations

X-ray radiotherapy is a common method of treating cancerous tumors or other malignant lesions. The side effects of this treatment, however, can be deleterious to patient quality of life if critical tissues are affected. To potentially lower the effective doses of radiation and negative side-effects, new classes of nanoparticles are being developed to enhance reactive oxygen species production during irradiation. This report presents the synthesis and radiotherapeutic efficacy evaluation of a new nanoparticle formulation designed for this purpose, composed of a CaF2 core, mesoporous silica shell, and polyethylene glycol coating. The construct was additionally doped with Tb and Eu …


Openfoam Simulations Of Late Stage Container Draining In Microgravity, Joshua Thomas Mccraney, Mark M. Weislogel, Paul Steen Jan 2020

Openfoam Simulations Of Late Stage Container Draining In Microgravity, Joshua Thomas Mccraney, Mark M. Weislogel, Paul Steen

Mechanical and Materials Engineering Faculty Publications and Presentations

In the reduced acceleration environment aboard orbiting spacecraft, capillary forces are often exploited to access and control the location and stability of fuels, propellants, coolants, and biological liquids in containers (tanks) for life support. To access the ‘far reaches’ of such tanks, the passive capillary pumping mechanism of interior corner networks can be employed to achieve high levels of draining. With knowledge of maximal corner drain rates, gas ingestion can be avoided and accurate drain transients predicted. In this paper, we benchmark a numerical method for the symmetric draining of capillary liquids in simple interior corners. The free surface is …


An Integrated Feasibility Study Of Reservoir Thermal Energy Storage (Rtes) In Portland, Or, Usa, John Bershaw, Alison E. Horst, Ashley Streig, Darby Patrick Scanlon, Ellen Elizabeth Svadlenak, Jenny Liu, Peter Hulseman, Ray E. Wells, Multiple Additional Authors Jan 2020

An Integrated Feasibility Study Of Reservoir Thermal Energy Storage (Rtes) In Portland, Or, Usa, John Bershaw, Alison E. Horst, Ashley Streig, Darby Patrick Scanlon, Ellen Elizabeth Svadlenak, Jenny Liu, Peter Hulseman, Ray E. Wells, Multiple Additional Authors

Geology Faculty Publications and Presentations

In regions with long cold overcast winters and sunny summers, Deep Direct-Use (DDU) can be coupled with Reservoir Thermal Energy Storage (RTES) technology to take advantage of pre-existing subsurface permeability to save summer heat for later use during cold seasons. Many aquifers worldwide are underlain by permeable regions (reservoirs) containing brackish or saline groundwater that has limited beneficial use due to poor water quality. We investigate the utility of these relatively deep, slow flowing reservoirs for RTES by conducting an integrated feasibility study in the Portland Basin, Oregon, USA, developing methods and obtaining results that can be widely applied to …


Chronic Chemogenetic Stimulation Of The Nucleus Accumbens Produces Lasting Reductions In Binge Drinking And Ameliorates Alcohol-Related Morphological And Transcriptional Changes, Dar'ya Y. Pozhidayeva, Sean Farris, Calla Goeke, Evan Firsick, Kayla G. Townsley, Marina Guizzetti, Angela Ozburn Jan 2020

Chronic Chemogenetic Stimulation Of The Nucleus Accumbens Produces Lasting Reductions In Binge Drinking And Ameliorates Alcohol-Related Morphological And Transcriptional Changes, Dar'ya Y. Pozhidayeva, Sean Farris, Calla Goeke, Evan Firsick, Kayla G. Townsley, Marina Guizzetti, Angela Ozburn

Chemistry Faculty Publications and Presentations

Binge drinking is a dangerous pattern of behavior. We tested whether chronically manipulating nucleus accumbens (NAc) activity (via clozapine-N-oxide (CNO) and Designer Receptors Exclusively Activated by Designer Drugs (DREADD)) could produce lasting eects on ethanol binge-like drinking in mice selectively bred to drink to intoxication. We found chronically increasing NAc activity (4 weeks, via CNO and the excitatory DREADD, hM3Dq) decreased binge-like drinking, but did not observe CNO-induced changes in drinking with the inhibitory DREADD, hM4Di. The CNO/hM3Dq-induced reduction in ethanol drinking persisted for at least one week, suggesting adaptive neuroplasticity via transcriptional and epigenetic mechanisms. Therefore, we defined this …


Boron Trifluoride Etherate Promoted Microwave Assisted Synthesis Of Antimalarial Acridones, Papireddy Kancharla, Rozalia A. Dodean, Yuexin Li, Jane X. Kelly Jan 2020

Boron Trifluoride Etherate Promoted Microwave Assisted Synthesis Of Antimalarial Acridones, Papireddy Kancharla, Rozalia A. Dodean, Yuexin Li, Jane X. Kelly

Chemistry Faculty Publications and Presentations

A microwave-assisted, rapid and efficient method using boron trifluoride etherate (BF3.Et2O) for the synthesis of acridones, via an intramolecular acylation of N-phenylanthranilic acid derivatives, has been developed. The reaction proceeds under solvent-free conditions, tolerates a wide range of functional groups, and provides rapid access to a range of acridones in good to excellent yields. Several of the synthesized acridones exhibited potent antimalarial activities against CQ sensitive and multi-drug resistant (MDR) parasites.


A Simple Predictive Model For Estimating Relative E-Cigarette Toxic Carbonyl Levels, Shawna Vreeke, Xijing Zhu, Robert Strongin Jan 2020

A Simple Predictive Model For Estimating Relative E-Cigarette Toxic Carbonyl Levels, Shawna Vreeke, Xijing Zhu, Robert Strongin

Chemistry Faculty Publications and Presentations

E-cigarette devices are wide ranging, leading to significant differences in levels of toxic carbonyls in their respective aerosols. Power can be a useful method in predicting relative toxin concentrations within the same device, but does not correlate well to inter-device levels. Herein, we have developed a simple mathematical model utilizing parameters of an e-cigarette’s coil and wick in order to predict relative levels of e-liquid solvent degradation. Model 1, which is coil length/(wick surface area*wraps), performed in the moderate-to-substantial range as a predictive tool (R2 = 0.69). Twelve devices, spanning a range of coil and wick styles, were analyzed. Model …


A Statistical Analysis Of Trans-Resveratrol In Grape Cane From Ten Varieties Of Cultivated Wine Grapes (Vitus Spp.), Harold Rathburn, Peter Bell, Scott Cook, Darrell D. Mayberry, Emryse Geye, Ryann Goodrich Jan 2020

A Statistical Analysis Of Trans-Resveratrol In Grape Cane From Ten Varieties Of Cultivated Wine Grapes (Vitus Spp.), Harold Rathburn, Peter Bell, Scott Cook, Darrell D. Mayberry, Emryse Geye, Ryann Goodrich

Chemistry Faculty Publications and Presentations

trans-Resveratrol (resveratrol) has been shown to have various health benefits. As a consequence, there is an effort to determine plentiful sources of this molecule. Certain plants, such as grapes, synthesize resveratrol and therefore appear to be an excellent source of this chemical. Annual pruning of grapevine yields significant amounts of cane material that is normally mulched or simply burned. Previous studies have shown this grape cane to contain economically useful resveratrol. Texas is the seventh largest producer of grapes in the USA with over 162 ha currently under cultivation. As a result it is estimated that more than $3.2 …


A Quantum Algorithm For Automata Encoding, Edison Tsai, Marek Perkowski Jan 2020

A Quantum Algorithm For Automata Encoding, Edison Tsai, Marek Perkowski

Electrical and Computer Engineering Faculty Publications and Presentations

Encoding of finite automata or state machines is critical to modern digital logic design methods for sequential circuits. Encoding is the process of assigning to every state, input value, and output value of a state machine a binary string, which is used to represent that state, input value, or output value in digital logic. Usually, one wishes to choose an encoding that, when the state machine is implemented as a digital logic circuit, will optimize some aspect of that circuit. For instance, one might wish to encode in such a way as to minimize power dissipation or silicon area. For …


Introduction To The Design And Simulation Of Reflectionless Filters, G. Lemire, Branimir Pejcinovic Jan 2020

Introduction To The Design And Simulation Of Reflectionless Filters, G. Lemire, Branimir Pejcinovic

Electrical and Computer Engineering Faculty Publications and Presentations

One novel approach to improving filter performance is to use so-called reflectionless filters which have recently been proposed. In this paper we demonstrate how to design, simulate and manufacture a reference reflectionless low-pass filter with the corner frequency of 188 MHz. We have found very good agreement between measurements, simulations, and published data, which validates our implementation of the design procedure. We have also designed a comparable diplexer so that we can examine the relative advantages and disadvantages of the reflectionless filters vs. diplexers. Measurements, simulations and published data, all agree very well in this case as well. This agreement …


Design Of Rubrics For Student Outcomes In 2019-2020 Abet Criteria, Branimir Pejcinovic Jan 2020

Design Of Rubrics For Student Outcomes In 2019-2020 Abet Criteria, Branimir Pejcinovic

Electrical and Computer Engineering Faculty Publications and Presentations

ABET is the main accreditation body for engineering programs in the United States and they have recently introduced a new set of Student Outcomes. This set was reduced from 11 to 7 items by combining several outcomes into one and adding some new ones. In our electrical and computer engineering programs we decided to design a set of seven general rubrics, one for each ABET outcome. These rubrics could then be used unaltered if course content fits them, or they can be adjusted to fit a particular course. To use a common description for rubrics, we wanted to keep the …


Quantum Algorithms And Experiment Implementations Based On Ibm Q, Wenjie Liu, Junxui Chen, Yinsong Xu, Jiahao Tang, Lain Tong, Xiaoyu Song Jan 2020

Quantum Algorithms And Experiment Implementations Based On Ibm Q, Wenjie Liu, Junxui Chen, Yinsong Xu, Jiahao Tang, Lain Tong, Xiaoyu Song

Electrical and Computer Engineering Faculty Publications and Presentations

With the rapid development of quantum theory and technology in recent years, especially the emergence of some quantum cloud computing platforms, more and more researchers are not satisfied with the theoretical derivation and simulation verification of quantum computation (especially quantum algorithms), experimental verification on real quantum devices has become a new trend. In this paper, three representative quantum algorithms, namely Deutsch-Jozsa, Grover, and Shor algorithms, are briefly depicted, and then their implementation circuits are presented, respectively. We program these circuits on python with QISKit to connect the remote real quantum devices (i.e., ibmqx4, ibmqx5) on IBM Q to verify these …


Sediment Interval Velocities From A Monostatic Multibeam Sonar, Charles W. Holland, Samuel Pinson Jan 2020

Sediment Interval Velocities From A Monostatic Multibeam Sonar, Charles W. Holland, Samuel Pinson

Electrical and Computer Engineering Faculty Publications and Presentations

Interval velocities for marine sediments are generally obtained from source-receiver separations at various offsets. A method is described for estimating interval velocities using a monostatic configuration. Testing is performed using simulated data from rough layered seabeds and interval velocity is estimated within less than 1% of the true value. Monostatic multibeam data from the Gulf of Lion are also presented which exhibit many characteristics similar to the simulated data. The method applied to the measured data yield an interval velocity of 1569 m/s in an 18m sediment layer. This accords with nearby independent data from cores and wide-angle reflection analysis. …


A Dynamic Neural Network Designed Using Analytical Methods Produces Dynamic Control Properties Similar To An Analogous Classical Controller, Wade William Hilts, Nicholas Szczecinski, Roger Quinn, Alexander Hunt Jan 2020

A Dynamic Neural Network Designed Using Analytical Methods Produces Dynamic Control Properties Similar To An Analogous Classical Controller, Wade William Hilts, Nicholas Szczecinski, Roger Quinn, Alexander Hunt

Mechanical and Materials Engineering Faculty Publications and Presentations

Human balance is achieved using many concurrent control loops that combine to react to changes in environment, posture, center of mass and other factors affecting stability. Though numerous engineering models of human balance control have been tested, no methods for porting these models to a neural architecture have been established. It is our hypothesis that the analytical methods we have developed, combined with classical control techniques will provide a reasonable starting point for developing dynamic neural controllers that can reproduce classical control capabilities. In previous work, we tested this hypothesis and demonstrated that a biologically-constrained neural controller that replicates human …


Modelling Lagrangian Velocity And Acceleration In Turbulent Flows As Infinitely Differentiable Stochastic Process, Bianca Fontanin Viggiano, Jan Friedrich, Romain Volk, Mickael Bourgoin, Raúl Bayoán Cal, Laurent Chevillard Jan 2020

Modelling Lagrangian Velocity And Acceleration In Turbulent Flows As Infinitely Differentiable Stochastic Process, Bianca Fontanin Viggiano, Jan Friedrich, Romain Volk, Mickael Bourgoin, Raúl Bayoán Cal, Laurent Chevillard

Mechanical and Materials Engineering Faculty Publications and Presentations

We develop a stochastic model for Lagrangian velocity as it is observed in experimental and numerical fully developed turbulent flows. We define it as the unique statistically stationary solution of a causal dynamics, given by a stochastic differential equation. In comparison to previously proposed stochastic models, the obtained process is infinitely differentiable at a given finite Reynolds number, and its second-order statistical properties converge to those of an Ornstein-Uhlenbeck process in the infinite Reynolds number limit. In this limit, it exhibits furthermore intermittent scaling properties, as they can be quantified using higher-order statistics. To achieve this, we begin with generalizing …


Deuterium Excess And 17o-Excess Variability In Meteoric Water Across The Pacific Northwest, Usa, John Bershaw, Dougal Hansen, Andrew Schauer Jan 2020

Deuterium Excess And 17o-Excess Variability In Meteoric Water Across The Pacific Northwest, Usa, John Bershaw, Dougal Hansen, Andrew Schauer

Geology Faculty Publications and Presentations

High-precision triple oxygen isotope analysis of water has given rise to a novel second-order parameter, 17O-excess (often denoted as δ17O), which describes the deviation from a reference relationship between δ18O and δ17O. This tracer, like deuterium excess (d-excess), is affected by kinetic fractionation (diffusion) during phase changes within the hydrologic cycle. However, unlike d-excess, 17O-excess is present in paleowater proxy minerals and is not thought to vary significantly with temperature. This makes it a promising tool in paleoclimate research, particularly in relatively arid continental regions where traditional approaches have produced equivocal results. …


The Role Of Warm, Dry Summers And Variation In Snowpack On Phytoplankton Dynamics In Mountain Lakes, Isabella A. Olesky, Whitney S. Beck, Roderick W. Lammers, Cara E. Steger, Codie Wilson, Kyle R. Christianson, Kim Vincent, Gunnar Forrest Johnson, Pieter T.J. Johnson, Jill S. Baron Jan 2020

The Role Of Warm, Dry Summers And Variation In Snowpack On Phytoplankton Dynamics In Mountain Lakes, Isabella A. Olesky, Whitney S. Beck, Roderick W. Lammers, Cara E. Steger, Codie Wilson, Kyle R. Christianson, Kim Vincent, Gunnar Forrest Johnson, Pieter T.J. Johnson, Jill S. Baron

Geology Faculty Publications and Presentations

Climate change is altering biogeochemical, metabolic, and ecological functions in lakes across the globe. Historically, mountain lakes in temperate regions have been unproductive because of brief ice-free seasons, a snowmelt-driven hydrograph, cold temperatures, and steep topography with low vegetation and soil cover. We tested the relative importance of winter and summer weather, watershed characteristics, and water chemistry as drivers of phytoplankton dynamics. Using boosted regression tree models for 28 mountain lakes in Colorado, we examined regional, intraseasonal, and interannual drivers of variability in chlorophyll a as a proxy for lake phytoplankton. Phytoplankton biomass was inversely related to the maximum snow …


Computer Science For Equity: Teacher Education, Agency, And Statewide Reform, Joanna Goode, Max Skorodinsky, Jill Hubbard, James Hook Jan 2020

Computer Science For Equity: Teacher Education, Agency, And Statewide Reform, Joanna Goode, Max Skorodinsky, Jill Hubbard, James Hook

Computer Science Faculty Publications and Presentations

This paper reports on a statewide “Computer Science for All” initiative in Oregon that aims to democratize high school computer science and broaden participation in an academic subject that is one of the most segregated disciplines nationwide, in terms of both race and gender. With no statewide policies to support computing instruction, Oregon's legacy of computer science education has been marked by both low participation and by rates of underrepresented students falling well-below the already dismal national rates. The study outlined in this paper focuses on how teacher education can support educators in developing knowledge and agency, and impacting policies …


A Basilosaurid Archaeocete (Cetacea, Pelagiceti) From The Late Eocene Of Oregon, Usa, Mark D. Uhen, David Taylor Jan 2020

A Basilosaurid Archaeocete (Cetacea, Pelagiceti) From The Late Eocene Of Oregon, Usa, Mark D. Uhen, David Taylor

Geology Faculty Publications and Presentations

Background: Basilosaurid archaeocetes are known from the Late Eocene of virtually all coastlines bearing coeval marine rocks except the North Pacific Basin, until now. Here we report on three consecutive posterior thoracic vertebrae of a large, basilosaurid archaeocete from a Late Eocene horizon in the Keasey Formation in Oregon.

Methods: These vertebrae were morphologically and morphometrically compared to other vertebrae of similar age from around the world.

Results: The specimens were determined to be different from all currently named species of fossil cetacean, but most similar to those found in the Gulf Coast region of North America. …


Predicted Responses Of Beaches, Bays, And Inner-Shelf Sand Supplies To Potential Sea Level Rise (0.5-1.0 M) In Three Small Littoral Subcells In The High-Wave-Energy Northern Oregon Coast, Usa, Curt D. Peterson, Debra Lee Doyle, Charles L. Rosenfeld, Kara E. P. Kingen Jan 2020

Predicted Responses Of Beaches, Bays, And Inner-Shelf Sand Supplies To Potential Sea Level Rise (0.5-1.0 M) In Three Small Littoral Subcells In The High-Wave-Energy Northern Oregon Coast, Usa, Curt D. Peterson, Debra Lee Doyle, Charles L. Rosenfeld, Kara E. P. Kingen

Geology Faculty Publications and Presentations

Three small subcells (Nehalem, Tillamook, and Netarts) totaling ~55 km shoreline length in the high-wave energy northern Oregon coast are evaluated for potential beach sand loss from sea level rise (SLR) of 0.5–1.0 m during the next century. The predicted erosion is based on beach sand displacement from the narrow beaches (average ~120 m width) to increased submarine accommodation spaces in the innermost-shelf (to 30 m water depth) and in the subcell estuaries (Tillamook Bay, Netarts Bay, and Nehalem Bay), following predicted near-future SLR. Beach sand sources from local rivers, paleo-shelf deposits, and/or sea cliff retreat are discriminated by distinctive …


Northward Migration Of The Oregon Forearc On The Gales Creek Fault, Ray E. Wells, Richard J. Blakely, Sean Bemis Jan 2020

Northward Migration Of The Oregon Forearc On The Gales Creek Fault, Ray E. Wells, Richard J. Blakely, Sean Bemis

Geology Faculty Publications and Presentations

The Gales Creek fault (GCF) is a 60-km-long, northwest-striking dextral fault system (west of Portland, Oregon) that accommodates northward motion and uplift of the Oregon Coast Range. New geologic mapping and geophysical models confirm inferred offsets from earlier geophysical surveys and document ∼12 km of right-lateral offset of a basement high in Eocene Siletz River Volcanics since ca. 35 Ma and ∼8.8 km of right-lateral separation of Miocene Columbia River Basalt at Newberg, Oregon, since 15 Ma (∼0.62 ± 0.12 mm/yr, average long-term rate). Relative uplift of Eocene Coast Range basalt basement west of the fault zone is at least …


Onset And Cause Of Increased Seismic Activity Near Pecos, West Texas, United States, From Observations At The Lajitas Txar Seismic Array, Clive Frohlich, Chris Hayward, Julia Rosenblit, Chastity Aiken, Peter Henning, Alexandros Savvaidis, Casee Lemons, Elizabeth Horne, Multiple Additional Authors Jan 2020

Onset And Cause Of Increased Seismic Activity Near Pecos, West Texas, United States, From Observations At The Lajitas Txar Seismic Array, Clive Frohlich, Chris Hayward, Julia Rosenblit, Chastity Aiken, Peter Henning, Alexandros Savvaidis, Casee Lemons, Elizabeth Horne, Multiple Additional Authors

Geology Faculty Publications and Presentations

In recent years, numerous small earthquakes have occurred near the town of Pecos in West Texas; however, when this activity began and whether it was caused by increased petroleum industry activity has been uncertain because prior to 2017 there were few permanent seismograph stations in the region. We identify and locate earthquakes using data recorded since 2000 at TXAR, a sensitive 10‐station seismic array situated about 240 km south of Pecos. We thus show that in 2007, one earthquake occurred near Pecos, in 2009 several more occurred, and subsequently, activity has increased considerably, with more than 2000 events identified in …


The Seasonal Evolution Of Albedo Across Glaciers And The Surrounding Landscape Of Taylor Valley, Antarctica, Anna Bergstrom, Michael N. Gooseff, Peter T. Doran, Julian M. Cross Jan 2020

The Seasonal Evolution Of Albedo Across Glaciers And The Surrounding Landscape Of Taylor Valley, Antarctica, Anna Bergstrom, Michael N. Gooseff, Peter T. Doran, Julian M. Cross

Geology Faculty Publications and Presentations

The McMurdo Dry Valleys (MDVs) of Antarctica are a polar desert ecosystem consisting of alpine glaciers, ice-covered lakes, streams, and expanses of vegetation-free rocky soil. Because average summer temperatures are close to 0 Cel., the MDV ecosystem in general, and glacier melt dynamics in particular, are both closely linked to the energy balance. A slight increase in incoming radiation or change in albedo can have large effects on the timing and volume of meltwater. However, the seasonal evolution or spatial variability of albedo in the valleys has yet to fully characterized. In this study, we aim to understand the drivers …


On Basing One-Way Permutations On Np-Hard Problems Under Quantum Reductions, Nai-Hui Chia, Sean Hallgren, Fang Song Jan 2020

On Basing One-Way Permutations On Np-Hard Problems Under Quantum Reductions, Nai-Hui Chia, Sean Hallgren, Fang Song

Computer Science Faculty Publications and Presentations

A fundamental pursuit in complexity theory concerns reducing worst-case problems to average-case problems. There exist complexity classes such as PSPACE that admit worst-case to average-case reductions. However, for many other classes such as NP, the evidence so far is typically negative, in the sense that the existence of such reductions would cause collapses of the polynomial hierarchy(PH). Basing cryptographic primitives, e.g., the average-case hardness of inverting one-way permutations, on NP-completeness is a particularly intriguing instance. As there is evidence showing that classical reductions from NP-hard problems to breaking these primitives result in PH collapses, it seems unlikely to base cryptographic …


Selectivity And Robustness Of Sparse Coding Networks, Dylan M. Paiton, Charles Frye, Sheng Y. Lundquist, Joel D. Bowen, Ryan Zarcone, Bruno A. Olshausen Jan 2020

Selectivity And Robustness Of Sparse Coding Networks, Dylan M. Paiton, Charles Frye, Sheng Y. Lundquist, Joel D. Bowen, Ryan Zarcone, Bruno A. Olshausen

Computer Science Faculty Publications and Presentations

We investigate how the population nonlinearities resulting from lateral inhibition and thresholding in sparse coding networks influence neural response selectivity and robustness. We show that when compared to pointwise nonlinear models, such population nonlinearities improve the selectivity to a preferred stimulus and protect against adversarial perturbations of the input. These findings are predicted from the geometry of the single-neuron iso-response surface, which provides new insight into the relationship between selectivity and adversarial robustness. Inhibitory lateral connections curve the iso-response surface outward in the direction of selectivity. Since adversarial perturbations are orthogonal to the iso-response surface, adversarial attacks tend to be …


Crossing Boundaries: Steps Toward Measuring Undergraduates' Interdisciplinary Science Understanding, Brie Tripp, Sophia A. Voronoff, Erin Shortlidge Jan 2020

Crossing Boundaries: Steps Toward Measuring Undergraduates' Interdisciplinary Science Understanding, Brie Tripp, Sophia A. Voronoff, Erin Shortlidge

Biology Faculty Publications and Presentations

A desired outcome of education reform efforts is for undergraduates to effectively integrate knowledge across disciplines in order to evaluate and address real-world issues. Yet there are few assessments designed to measure if and how students think interdisciplinarily. Here, a sample of science faculty were surveyed to understand how they currently assess students’ interdisciplinary science understanding. Results indicate that individual writing-intensive activities are the most frequently used assessment type (69%). To understand how writing assignments can accurately assess students’ ability to think interdisciplinarily, we used a preexisting rubric, designed to measure social science students’ interdisciplinary understanding, to assess writing assignments …


Student Sustainability Leadership Development At Portland State University: Developing Holistic Sustainability Leaders, Megan Suzanne Schneider Dec 2019

Student Sustainability Leadership Development At Portland State University: Developing Holistic Sustainability Leaders, Megan Suzanne Schneider

Dissertations and Theses

In order to address the myriad of social, economic, and environmental challenges the world is facing, we need to be able to engage in leadership that fosters collective action towards sustainable solutions. Higher education is an institution that can equip people with the abilities to engage in sustainability leadership. This master's thesis research explores how students develop sustainability leadership through their college experience. Nine students, who had been identified as sustainability leaders through their participation in the Student Sustainability Center (SSC), a co-curricular sustainability program at Portland State University, were selected to be part of this grounded theory research project. …


Systems Isomorphisms In Stochastic Dynamic Systems, Rajesh Venkatachalapathy Dec 2019

Systems Isomorphisms In Stochastic Dynamic Systems, Rajesh Venkatachalapathy

Dissertations and Theses

The identification of isomorphisms between disparate systems is an important focus of systems science. Such isomorphisms have not only conceptual and pedagogical value to systems science, but they also provide pragmatic value to specific disciplines by suggesting new ways to model familiar phenomena and by serving as reference models that show how even simple models can generate complex behavior. Specifically, this dissertation looks at certain classes of stochastic dynamic systems (SDS) and shows that similar equations can model phenomena in sociology and psychology. In both disciplines, what is modeled by these SDS isomorphisms is a certain type of reliability, defined …


Statistical Analysis Of Social Network Change, Teresa Danielle Schmidt Dec 2019

Statistical Analysis Of Social Network Change, Teresa Danielle Schmidt

Dissertations and Theses

This project explores two statistical methods that infer social network structures and statistically test those structures for change over time: regression-based differential network analysis (R-DNA) and information theory-based differential analysis (I-DNA). R-DNA is adapted from bioinformatics and I-DNA employs reconstructability analysis.

This project applies both R-DNA and I-DNA to analyze Medicaid claims data from one-year periods before (May 2011- Apr 2012) and after (Jan 2013-Dec 2013) the formation of the Health Share of Oregon Coordinated Care Organization (CCO). The formation of CCOs was legislated by the state of Oregon in 2012 with the triple aim of improving health outcomes, reducing …