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The Auxiliary Space Preconditioner For The De Rham Complex, Jay Gopalakrishnan, Martin Neumüller, Panayot S. Vassilevski May 2018

The Auxiliary Space Preconditioner For The De Rham Complex, Jay Gopalakrishnan, Martin Neumüller, Panayot S. Vassilevski

Portland Institute for Computational Science Publications

We generalize the construction and analysis of auxiliary space preconditioners to the n-dimensional finite element subcomplex of the de Rham complex. These preconditioners are based on a generalization of a decomposition of Sobolev space functions into a regular part and a potential. A discrete version is easily established using the tools of finite element exterior calculus. We then discuss the four-dimensional de Rham complex in detail. By identifying forms in four dimensions (4D) with simple proxies, form operations are written out in terms of familiar algebraic operations on matrices, vectors, and scalars. This provides the basis for our implementation of …


Harnessing Social Media To Explore Youth Social Withdrawal In Three Major Cities In China: Cross-Sectional Web Survey, Lucia Lin Liu, Tim Mh Li, Alan R. Teo, Takahiro A. Kato, Paul W.C. Wong May 2018

Harnessing Social Media To Explore Youth Social Withdrawal In Three Major Cities In China: Cross-Sectional Web Survey, Lucia Lin Liu, Tim Mh Li, Alan R. Teo, Takahiro A. Kato, Paul W.C. Wong

OHSU-PSU School of Public Health Faculty Publications and Presentations

Background: Socially withdrawn youth belong to an emerging subgroup of youth who are not in employment, education, or training and who have limited social interaction intention and opportunities. The use of the internet and social media is expected to be an alternative and feasible way to reach this group of young people because of their reclusive nature.

Objective: The aim of this study was to explore the possibility of using various social media platforms to investigate the existence of the phenomenon of youth social withdrawal in 3 major cities in China.

Methods: A cross-sectional open Web survey …


Disequilibrium Of Fire-Prone Forests Sets The Stage For A Rapid Decline In Conifer Dominance During The 21st Century, Josep M. Serra-Diaz, Charles Maxwell, Melissa S. Lucash, Robert M. Scheller, Danelle M. Laflower, Adam D. Miller, Alan J. Tepley, Howard E. Epstein, Kristina J. Anderson-Teixeira, Jonathan R. Thompson Apr 2018

Disequilibrium Of Fire-Prone Forests Sets The Stage For A Rapid Decline In Conifer Dominance During The 21st Century, Josep M. Serra-Diaz, Charles Maxwell, Melissa S. Lucash, Robert M. Scheller, Danelle M. Laflower, Adam D. Miller, Alan J. Tepley, Howard E. Epstein, Kristina J. Anderson-Teixeira, Jonathan R. Thompson

Environmental Science and Management Faculty Publications and Presentations

As trees are long-lived organisms, the impacts of climate change on forest communities may not be apparent on the time scale of years to decades. While lagged responses to environmental change are common in forested systems, potential for abrupt transitions under climate change may occur in environments where alternative vegetation states are influenced by disturbances, such as fire. The Klamath mountains (northern California and southwest Oregon, USA) are currently dominated by carbon rich and hyper-diverse temperate conifer forests, but climate change could disrupt the mechanisms promoting forest stability– regeneration and fire tolerance— via shifts in the fire regime in conjunction …


Fhwa Guidebook For Measuring Multimodal Network Connectivity, Joseph Broach Apr 2018

Fhwa Guidebook For Measuring Multimodal Network Connectivity, Joseph Broach

PSU Transportation Seminars

In 2016 the United States Department of Transportation (USDOT) Federal Highway Administration (FHWA) published a Guidebook for Developing Pedestrian and Bicycle Performance Measures that presents methods for measuring walking and bicycling performance and activities and embedding them into the transportation planning and decisionmaking process (U.S. Department of Transportation 2016). Building on the 2016 guidebook, this resource focuses on pedestrian and bicycle network connectivity and provides information on incorporating connectivity measures into state, metropolitan, and local transportation planning processes.

Connectivity measures can help transportation practitioners identify high priority network gaps, implement cost-effective solutions that address multiple needs, optimize potential co-benefits, and …


The Pivotal Role That Race Plays In Medical Research: The Tuskegee Syphilis Study, Kristin X. Wong Apr 2018

The Pivotal Role That Race Plays In Medical Research: The Tuskegee Syphilis Study, Kristin X. Wong

Young Historians Conference

This research attempts to answer the question, "To what extent was race or racial bias a factor in the conception and execution of the Tuskegee Study of Untreated Syphilis in the Negro Male?" The goal is to reevaluate the degree to which the Tuskegee Syphilis Study (TSS) was driven by the racial bias in the face of modern counter-narratives. This has been done by examining events such as the Oslo Study and the Rosenwald Demonstration Project, organizations such as the Public Health Service and Department of Health, Education, and Welfare, and primary and secondary sources including interviews, a collection of …


Galen: The Philosophical Physician, Chloe Sellers Apr 2018

Galen: The Philosophical Physician, Chloe Sellers

Young Historians Conference

Analyzing the works of Socrates, Plato and Aristotle, this paper reveals the specific influences each of the three had upon Galen’s medical practice, asserting that the influence of philosophy was ultimately responsible for distinguishing Galen from his contemporaries. Drawing from various primary sources, including Plato’s “The Apology,” Timaeus and The Republic, as well as Aristotle’s Physics, and comparing them to Galen’s works, “The Art of Medicine” and “A Method of Medicine to Glaucon,” numerous similarities are revealed between the works of Galen and those of the philosophical trio. By evaluating these many connections among the works, as well as using …


African Americans In Portland, A History Of Displacement And Exclusion, Brock Gjesdal Apr 2018

African Americans In Portland, A History Of Displacement And Exclusion, Brock Gjesdal

Young Historians Conference

Throughout the history of Portland, African Americans living within the city have been subject to discrimination and hardship by the hand of whites living among them, but not willing to live beside them. For this reason, whites enforced housing regulations to concentrate most of the African Americans living in Portland into the Northeast reaches of the city, more specifically the Albina District. However, as African American inequality in Portland gathered more and more recognition, the blunt racism embodied by the restrictive housing covenants that had been imposed upon African Americans for decades became less and less acceptable by the 1950s. …


Does Scale Matter? A Systematic Review Of Incorporating Biological Realism When Predicting Changes In Species Distributions, Sydne Record, Angela L. Strecker, Mao-Ning Tuanmu, Lydia Beaudrot, Phoebe Zarnetske, Jonathan Belmaker, Beth Gerstner Apr 2018

Does Scale Matter? A Systematic Review Of Incorporating Biological Realism When Predicting Changes In Species Distributions, Sydne Record, Angela L. Strecker, Mao-Ning Tuanmu, Lydia Beaudrot, Phoebe Zarnetske, Jonathan Belmaker, Beth Gerstner

Environmental Science and Management Faculty Publications and Presentations

Background: There is ample evidence that biotic factors, such as biotic interactions and dispersal capacity, can affect species distributions and influence species’ responses to climate change. However, little is known about how these factors affect predictions from species distribution models (SDMs) with respect to spatial grain and extent of the models.

Objectives: Understanding how spatial scale influences the effects of biological processes in SDMs is important because SDMs are one of the primary tools used by conservation biologists to assess biodiversity impacts of climate change.

Data sources and study eligibility criteria: We systematically reviewed SDM studies published …


Combined Theoretical And Experimental Investigation Of Hydrogen Production Catalysis, Carolyn Noelle Virca Apr 2018

Combined Theoretical And Experimental Investigation Of Hydrogen Production Catalysis, Carolyn Noelle Virca

Dissertations and Theses

The widespread use of solar energy has been limited in part by the issue of effective storage. Water splitting is a means of converting solar energy into chemical fuel, in the form of hydrogen gas. It can be performed through both photochemical and electrochemical processes, via the two half reactions of water oxidation and proton reduction. Electrochemically, the catalyst receives electrons from an external circuit, which can be coupled to a renewable source such as a solar cell. Photochemically, a light-absorbing molecule provides an excited electron to a catalyst, which either generates oxygen or hydrogen gas. The work described herein …


Using Repeat Terrestrial Laser Scanning And Photogrammetry To Monitor Reactivation Of The Silt Creek Landslide In The Western Cascade Mountains, Linn County, Oregon, Justin Craig Mccarley Apr 2018

Using Repeat Terrestrial Laser Scanning And Photogrammetry To Monitor Reactivation Of The Silt Creek Landslide In The Western Cascade Mountains, Linn County, Oregon, Justin Craig Mccarley

Dissertations and Theses

Landslides represent a serious hazard to people and property in the Pacific Northwest. Currently, the factors leading to sudden catastrophic failure vs. gradual slow creeping are not well understood. Utilizing high-resolution monitoring techniques at a sub-annual temporal scale can help researchers better understand the mechanics of mass wasting processes and possibly lead to better mitigation of their danger. This research used historical imagery analysis, precipitation data, aerial lidar analysis, Structure from Motion (SfM) photogrammetry, terrestrial laser scanning (TLS), and hydrologic measurements to monitor displacement of the Silt Creek Landslide in the western Cascade Mountain Range in Linn County, Oregon. This …


Areal Extent And Volumes Of The Dinner Creek Tuff Units, Eastern Oregon Based On Lithology, Bulk Rock Composition And Feldspar Mineralogy, Teresa Rae Hanna Apr 2018

Areal Extent And Volumes Of The Dinner Creek Tuff Units, Eastern Oregon Based On Lithology, Bulk Rock Composition And Feldspar Mineralogy, Teresa Rae Hanna

Dissertations and Theses

The Dinner Creek Tuff erupted during a period of rhyolitic volcanism coeval to the flood volcanism associated with the Columbia River Basalt Group. The High Rock Caldera Complex, Lake Owyhee and McDermitt volcanic fields account for ~90% of the rhyolites erupted between 16.7-15.0 Ma. Situated at the northern end of the Lake Owyhee volcanic field, the Dinner Creek Tuff was originally mapped as a ~2,000 km2 single ignimbrite confined to the Malheur Gorge. Streck et al. (2015) correlated tuff outcrops previously mapped as generic Miocene welded tuff as well as local units such as the "Mascall" or "Pleasant Valley" …


Design Optimization For A Cnc Machine, Alin Resiga Apr 2018

Design Optimization For A Cnc Machine, Alin Resiga

Dissertations and Theses

Minimizing cost and optimization of nonlinear problems are important for industries in order to be competitive. The need of optimization strategies provides significant benefits for companies when providing quotes for products. Accurate and easily attained estimates allow for less waste, tighter tolerances, and better productivity. The Nelder-Mead Simplex method with exterior penalty functions was employed to solve optimum machining parameters. Two case studies were presented for optimizing cost and time for a multiple tools scenario. In this study, the optimum machining parameters for milling operations were investigated. Cutting speed and feed rate are considered as the most impactful design variables …


Quantifying Knickpoint Behavior And Erosion Mechanisms In An Urbanized Watershed, Bull Mountain, Washington County, Oregon, Max Gregory Bordal Apr 2018

Quantifying Knickpoint Behavior And Erosion Mechanisms In An Urbanized Watershed, Bull Mountain, Washington County, Oregon, Max Gregory Bordal

Dissertations and Theses

Quantifying spatial and temporal patterns of rapid channelized erosion, on human time scales, is critical to understanding its processes and their consequences. This investigation utilized field observations, repeat terrestrial laser scanning (TLS), and Structure-from-Motion photogrammetry (SfM) to document the size and retreat rates of a knickpoint, defined as a localized near-vertical reach of a fluvial channel, and its contribution to erosion, in an urbanizing landscape with a loess substrate. The Bull Mountain area, in Washington County, southwest of Portland, Oregon, is an ideal study area, offering a measurable knickpoint that translates the response of the rapid erosion throughout this transient …


The Role Of Culturally Responsive Pedagogy In The Preparation Of Secondary Teacher Candidates For Successful Teaching Of Diverse Learners: A Multiphase Mixed Methods Case Study, Rosalyn Taylor Apr 2018

The Role Of Culturally Responsive Pedagogy In The Preparation Of Secondary Teacher Candidates For Successful Teaching Of Diverse Learners: A Multiphase Mixed Methods Case Study, Rosalyn Taylor

Dissertations and Theses

The dramatic demographic shift occurring in this country makes it essential that our nation examines its policies, practices, and values as they relate to culturally diverse learners. That this student population remains underserved needs immediate attention. One arena that can become a part of the solution to the underachievement of diverse learners is teacher education and preparation programming.

The purpose of this research study was to give attention to this issue and to understand what an urban teacher education program (UTEP) with an educational equity and social justice mission does to prepare its secondary teacher candidates (STCs) to work successfully …


Trajectories Of The Expression Of Negative Emotion From Kindergarten To First Grade: Associations With Academic Outcomes, Maciel M. Hernández, Nancy Eisenberg, Carlos Valiente, Marilyn S. Thompson, Tracy L. Spinrad, Kevin J. Grimm, Sarah K. Vanschyndel, Rebecca H. Berger, Kassondra M. Silva, Armando A. Pina, Jody Southworth, Diana E. Gal Apr 2018

Trajectories Of The Expression Of Negative Emotion From Kindergarten To First Grade: Associations With Academic Outcomes, Maciel M. Hernández, Nancy Eisenberg, Carlos Valiente, Marilyn S. Thompson, Tracy L. Spinrad, Kevin J. Grimm, Sarah K. Vanschyndel, Rebecca H. Berger, Kassondra M. Silva, Armando A. Pina, Jody Southworth, Diana E. Gal

Psychology Faculty Publications and Presentations

We examined individual trajectories, across four time points, of children’s (N = 301) expression of negative emotion in classroom settings and whether these trajectories predicted their observed school engagement, teacher-reported academic skills, and passage comprehension assessed with a standardized measure in first grade. In latent growth curve analyses, negative expressivity declined from kindergarten to first grade, with significant individual differences in trajectories. Negative expressivity in kindergarten inversely predicted first-grade school engagement and teacher-reported academic skills, and the slope of negative expressivity from kindergarten to first grade inversely predicted school engagement (e.g., increasing negative expressivity was associated with lower school engagement). …


Transition With Purpose: Pathways From English Language To Academic Study, Michele Miller, Anne Greenhoe Apr 2018

Transition With Purpose: Pathways From English Language To Academic Study, Michele Miller, Anne Greenhoe

PDXOpen: Open Educational Resources

This Open Access Textbook will guide students through their English language to academic degree studies.

Part one of this textbook is a guide for moving from ESL study to academic study at Portland State University*. It includes the resources students will use to understand policies and processes governing their degree study and their transition to academic coursework.

Part two focuses on how academic skills are used across various disciplines and is comprised of activities and assignments designed to practice these skills.

Key elements include culture and expectations in an American university, transferring academic skills from ESL to content-specific academic courses, …


The Preparation Of Diaryliodonium Salts For Application In Arylation Chemistry, Thomas Ludwig Seidl Apr 2018

The Preparation Of Diaryliodonium Salts For Application In Arylation Chemistry, Thomas Ludwig Seidl

Dissertations and Theses

Diaryliodonium salts offer potential as novel reagents for arylation chemistry. An overall goal and successful outcome of this work has been to further understanding of diaryliodonium salt chemistry by developing practical methods that enable chemists more convenient access to these reagents, for the purpose of reaction development. To this end a robust and convenient preparation method has been developed and resulted in novel commercially available diaryliodonium salts. The remainder of the work described, has focused on understanding the parameters important to diaryliodonium mediated arylation and has resulted in a solid framework that multiple future development efforts can build upon.

A …


Psu Market Center Building Leed Eb Materials Audit Report, Christa Mcdermott, Emily Murkland, Bryan Nguyen, Tay Stone, Rushada Wimer Apr 2018

Psu Market Center Building Leed Eb Materials Audit Report, Christa Mcdermott, Emily Murkland, Bryan Nguyen, Tay Stone, Rushada Wimer

Campus Sustainability Office Publications, Reports and Presentations

This report provides Portland State University’s (PSU) Campus Sustainability Office (CSO), with an objective third party LEED O+M Materials Assessment of PSU’s Market Center Building (MCB). The data collected for this audit provides CSO with insight into the building’s current waste composition and diversion rate. Additionally, it identifies opportunities to reduce the amount of recoverable materials ending up in the landfill stream. Community Environmental Services (CES) conducted material audits for 100% of MCB’s landfill-bound, commingled recycling, glass bottles and jars recycling, and compost streams during a 24-hour period.


Evaluating The Applicability Of Modflow2005 Plus Mt3d-Usgs: Borden Case Study, Linley Mescher Apr 2018

Evaluating The Applicability Of Modflow2005 Plus Mt3d-Usgs: Borden Case Study, Linley Mescher

Civil and Environmental Engineering Master's Project Reports

Groundwater is essential to communities around the world for drinking, industrial, and agricultural purposes. MODFLOW is a modeling program that uses the three-dimensional continuity equation in a finite difference approach to simulate groundwater flow in an aquifer. MT3D-USGS is a MODFLOW package that simulates contaminant transport. This study used MODFLOW2005 with MT3D-USGS to build a model simulating contaminant transport in Borden, Ontario. A study conducted at the Borden site in 1982 injected a solution of eight solutes to test the transport of contaminants over three years. Initial simulations showed similar transport characteristics for chloride and carbon tetrachloride as compared to …


Assessing Transboundary Wildfire Exposure In The Southwestern United States, Alan A. Ager, Palaiologos Palaiologou, Cody Evers, Michelle A. Day, Ana M.G. Barros Apr 2018

Assessing Transboundary Wildfire Exposure In The Southwestern United States, Alan A. Ager, Palaiologos Palaiologou, Cody Evers, Michelle A. Day, Ana M.G. Barros

Environmental Science and Management Faculty Publications and Presentations

We assessed transboundary wildfire exposure among federal, state, and private lands and 447 communities in the state of Arizona, southwestern United States. The study quantified the relative magnitude of transboundary (incoming, outgoing) versus nontransboundary (i.e., self-burning) wildfire exposure based on land tenure or community of the simulated ignition and the resulting fire perimeter. We developed and described several new metrics to quantify and map transboundary exposure. We found that incoming transboundary fire accounted for 37% of the total area burned on large parcels of federal and state lands, whereas 63% of the area burned was burned by ignitions within the …


The Role Of Surface Vorticity During Unsteady Separation, Matthew Scott Melius, Karen Mulleners, Raul Bayoan Cal Apr 2018

The Role Of Surface Vorticity During Unsteady Separation, Matthew Scott Melius, Karen Mulleners, Raul Bayoan Cal

Mechanical and Materials Engineering Faculty Publications and Presentations

Unsteady flow separation in rotationally augmented flow fields plays a significant role in a variety of fundamental flows. Through the use of time-resolved particle image velocimetry, vorticity accumulation and vortex shedding during unsteady separation over a three-dimensional airfoil are examined. The results of the study describe the critical role of surface vorticity accumulation during unsteady separation and reattachment. Through evaluation of the unsteady characteristics of the shear layer, it is demonstrated that the buildup and shedding of surface vorticity directly influence the dynamic changes of the separation point location. The quantitative characterization of surface vorticity and shear layer stability enables …


High-Resolution Observations In The Western Mediterranean Sea: The Rep14-Med Experiment, Reiner Onken, Heinz-Volker Fiekas, Laurent Beguery, Ines Borrione, Andreas Funk, Michael Hemming, Jaime Hernandez-Lasheras, Karen J. Heywood, Jan Kaiser, Michaela Knoll, Baptiste Mourre, Paolo Oddo, Pierre-Marie Poulain, Bastien Y. Queste, Aniello Russo, Kiminori Shitashima, Martin Siderius, Elizabeth Thorp Küsel Apr 2018

High-Resolution Observations In The Western Mediterranean Sea: The Rep14-Med Experiment, Reiner Onken, Heinz-Volker Fiekas, Laurent Beguery, Ines Borrione, Andreas Funk, Michael Hemming, Jaime Hernandez-Lasheras, Karen J. Heywood, Jan Kaiser, Michaela Knoll, Baptiste Mourre, Paolo Oddo, Pierre-Marie Poulain, Bastien Y. Queste, Aniello Russo, Kiminori Shitashima, Martin Siderius, Elizabeth Thorp Küsel

Electrical and Computer Engineering Faculty Publications and Presentations

The observational part of the REP14-MED experiment was conducted in June 2014 in the Sardo-Balearic Basin west of Sardinia (western Mediterranean Sea). Two research vessels collected high-resolution oceanographic data by means of hydrographic casts, towed systems, and underway measurements. In addition, a vast amount of data was provided by a fleet of 11 ocean gliders, time series were available from moored instruments, and information on Lagrangian flow patterns was obtained from surface drifters and one profiling float. The spatial resolution of the observations encompasses a spectrum over 4 orders of magnitude from O(101 m) to O(105 m), and …


Hdm Model To Select Marketing Analyst Job Offer, Alex Tacco-Melendez Apr 2018

Hdm Model To Select Marketing Analyst Job Offer, Alex Tacco-Melendez

Engineering and Technology Management Student Projects

Times have changed and we no longer pick a career in terms of climbing the corporate ladder or to continue with a “family profession tradition” that will make our parents happy. We now select an occupation based on the satisfaction and fulfillment it will bring to our lives.

Nowadays, people spend significantly more time on the job than in any other single activity, making this a crucial decision that will influence their lifestyles.

Recent graduates and entry-level professionals are not only interested in receiving a fair remuneration at the end of each month, they are also seeking for companies that …


Technological Evolution In Software Engineering, Cody Miller Apr 2018

Technological Evolution In Software Engineering, Cody Miller

Engineering and Technology Management Student Projects

In all software development processes, the software must evolve in response to its environment or user needs to maintain satisfactory performance. If software doesn’t support change, it gradually becomes useless. With many organizations today, being software-centric organizations, this has huge implications for their business: evolve your software, or risk your software becoming gradually useless, and therefore, your entire business.

Technology Evolution is a highly relevant subject, Intel’s business model for the last 50 years, has been that of Moore’s Law, a hardware centric Technology Evolution model. As a Software Engineer at Intel, our business group faces a similar issue, we …


Effects Of Beaver Dams On Urban Stream Hydraulic Response During Storm Events, Erin Poor Apr 2018

Effects Of Beaver Dams On Urban Stream Hydraulic Response During Storm Events, Erin Poor

Environmental Science and Management Professional Master's Project Reports

Urbanization of landscapes alters watershed hydrology, leading to changes in the natural flow regime of local streams. Runoff from impervious surfaces and routing of stormwater can cause a rapid increase in the volume and velocity of streamflow. This is observed in the hydrograph as a steep rising limb, followed by a high peak, and a rapid falling limb. This rapidly varying streamflow, often referred to as flashiness, can increase erosive forces on the channel bed and banks, leading to channel incision and bank erosion. In areas where the hydrologic regime is less impacted by humans, beaver dams and ponds attenuate …


Addressing Bicycle-Vehicle Conflicts With Alternate Signal Control Strategies, Sirisha Kothuri, Andrew Kading, Andrew Schrope, Kelly White, Edward Smaglik, Chris Aguilar, William Gil Apr 2018

Addressing Bicycle-Vehicle Conflicts With Alternate Signal Control Strategies, Sirisha Kothuri, Andrew Kading, Andrew Schrope, Kelly White, Edward Smaglik, Chris Aguilar, William Gil

TREC Final Reports

Over the last decade there has been increased interest in promoting active and sustainable transportation modes such as bicycling and walking especially in urban areas, as a means to alleviate congestion, lower emission levels and improve personal health. In urban areas, intersections are locations where a variety of modes converge, thus increasing the propensity for conflicts. Many bicycle-vehicle crashes occur at intersections. A common crash type involving bicycles at intersections is the “right-hook” where a right-turning vehicle collides with a through bicyclist. Intersections are also the source of increased stress for many bicyclists where the interactions with cars are more …


Newwater Regimes: An Editorial, Alida Cantor, Jacque Emel Apr 2018

Newwater Regimes: An Editorial, Alida Cantor, Jacque Emel

Geography Faculty Publications and Presentations

This editorial is an introduction to the special issue of Resources on New Water Regimes. The special issue explores legal geographies of water resource management with the dual goals of providing critiques of existing water management practices as well as exploring potential alternatives. The papers in the special issue draw from numerous theoretical perspectives, including decolonial and post-anthropocentric approaches to water governance; social and environmental justice in water management; and understanding legal ecologies. A variety of themes of water governance are addressed, including water allocation, groundwater management, collaborative governance, drought planning, and water quality. The papers describe and analyze water …


Towards Generalized Noise-Level Dependent Crystallographic Symmetry Classifications Of More Or Less Periodic Crystal Patterns, Peter Moeck Apr 2018

Towards Generalized Noise-Level Dependent Crystallographic Symmetry Classifications Of More Or Less Periodic Crystal Patterns, Peter Moeck

Physics Faculty Publications and Presentations

Geometric Akaike Information Criteria (G-AICs) for generalized noise-level dependent crystallographic symmetry classifications of two-dimensional (2D) images that are more or less periodic in either two or one dimensions as well as Akaike weights for multi-model inferences and predictions are reviewed. Such novel classifications do not refer to a single crystallographic symmetry class exclusively in a qualitative and definitive way. Instead, they are quantitative, spread over a range of crystallographic symmetry classes, and provide opportunities for inferences from all classes (within the range) simultaneously. The novel classifications are based on information theory and depend only on information that has been extracted …


Director Networks And Credit Ratings, Bradley W. Benson, Subramanian R. Iyer, Kristopher Kemper, Jing Zhao Apr 2018

Director Networks And Credit Ratings, Bradley W. Benson, Subramanian R. Iyer, Kristopher Kemper, Jing Zhao

Business Faculty Publications and Presentations

We explore the effect of director social capital, directors with large and influential networks, on credit ratings. Using a sample of 11,172 firm‐year observations from 1999 to 2011, we find that larger board networks are associated with higher credit ratings than both firm financial data and probabilities of default predict. Near‐investment grade firms improve their forward‐looking ratings when their board is more connected. Last, we find that larger director networks are more beneficial during recessions, and times of increased financial uncertainty. Our results are robust to controls for endogeneity. Tests confirm that causality runs from connected boards to credit ratings.


Using Spectral Methods To Obtain Particle Size Information From Optical Data: Applications To Measurements From Cares 2010, Dean B. Atkinson Apr 2018

Using Spectral Methods To Obtain Particle Size Information From Optical Data: Applications To Measurements From Cares 2010, Dean B. Atkinson

Chemistry Faculty Publications and Presentations

Multi-wavelength in situ aerosol extinction, absorption and scattering measurements made at two ground sites during the 2010 Carbonaceous Aerosols and Radiative Effects Study (CARES) are analyzed using a spectral deconvolution method that allows extraction of particle-sizerelated information, including the fraction of extinction produced by the fine-mode particles and the effective radius of the fine mode. The spectral deconvolution method is typically applied to analysis of remote sensing measurements. Here, its application to in situ measurements allows for comparison with more direct measurement methods and validation of the retrieval approach. Overall, the retrieved finemode fraction and effective radius compare well with …