Digital Commons Network^™

Assessing Transit Fare Equity In Utah Using A Geographic Information System, Steven Farber, Keith Batholomew, Xiao Li, Antonio Paez, Khandker M. Nurul Habib

TREC Final Reports

The goal of this study is to develop and apply a new method for assessing social equity impacts of distance-based public transit fares. Shifting to a distance-based fare structure can disproportionately favor or penalize different subgroups of a population based on variations in settlement patterns, travel needs, and most importantly, transit use. According to federal law, such disparities must be evaluated by the transit agency, but the area-based techniques identified by the Federal Transit Authority for assessing discrimination fail to account for disparities in distances travelled by transit users. This means that transit agencies currently lack guidelines for assessing the …

Report On The Workshop For Life Detection In Samples From Mars, Gerhard Kminek, Catherine Conley, Carlton C. Allen, Douglas H. Bartlett, David W. Beaty, Liane G. Benning, Rohit Bhatia, Penelope J. Boston, Caroline Duchaine, Jack D. Farmer, George J. Flynn, Daniel P. Glavin, Yuri Gorby, John E. Hallsworth, Rakesh Mogul, Duane Moser, P. Buford Price, Ruediger Pukall, David Fernandez-Remolar, Caroline L. Smith, Kenneth M. Stedman, Andrew Steele, Ramunas Stepanauskas, Henry Sun, Jorge L. Vago, Mary A. Voytek, Paul S. Weiss, Frances Westfall

Biology Faculty Publications and Presentations

The question of whether there is or was life on Mars has been one of the most pivotal since Schiaparellis’ telescopic observations of the red planet. With the advent of the space age, this question can be addressed directly by exploring the surface of Mars and by bringing samples to Earth for analysis. The latter, however, is not free of problems. Life can be found virtually everywhere on Earth. Hence the potential for contaminating the Mars samples and compromising their scientific integrity is not negligible. Conversely, if life is present in samples from Mars, this may represent a potential source …

Probabilistic Analysis For Reliable Logic Circuits, Scott Blakely

Dissertations and Theses

Continued aggressive scaling of electronic technology poses obstacles for maintaining circuit reliability. To this end, analysis of reliability is of increasing importance. Large scale number of inputs and gates or correlations of failures render such analysis computationally complex. This paper presents an accurate framework for reliability analysis of logic circuits, while inherently handling reconvergent fan-out without additional complexity. Combinational circuits are modeled stochastically as Discrete-Time Markov Chains, where propagation of node logic levels and error probability distributions through circuitry are used to determine error probabilities at nodes in the circuit. Model construction is scalable, as it is done so on …

Safety Verification Of Semi-Algebraic Dynamical Systems Via Inductive Invariant, Hui Kong, Fei He, Xiaoyu Song, Ming Gu, Hongyan Tan, Jiaguang Sun

Electrical and Computer Engineering Faculty Publications and Presentations

To verify the safety of nonlinear dynamical systems based on inductive invariants, key issues include defining the most complete inductive condition and discovering an inductive invariant that satisfies the specified inductive condition. In this paper, to lay a solid foundation for future research into the safety verification of semi-algebraic dynamical systems, we first establish a formal framework for evaluating the quality of continuous inductive conditions. In addition, we propose a new complete and computable inductive condition for verifying the safety of semi-algebraic dynamical systems. Compared with the existing complete and computable inductive condition, this new inductive condition can be easily …

Complex Thermal Histories Of L Melt Breccias Nwa 5964 And Nwa 6580, Kristy Lee Schepker

Dissertations and Theses

To constrain the thermal histories of two complex L chondrite melt breccia samples (NWA 5964 and NWA 6580) we compare textures and chemical compositions of metal and sulfide to L melt rock (NWA 6454 and NWA 6579) and strongly shocked (shock stage S6) (NWA 4860) samples. The inferred thermal histories can be used to evaluate formation settings on the L chondrite parent body. The L melt samples probably formed as different melt units within warm but largely unmelted material relatively close to the surface of the parent body, and the same is true for the S6 sample, except it experienced …

2014 Commencement Program (Morning Ceremony), Nicholas D. Kristof

Commencement Archives 2010-19

The program for the Portland State University 2014 Commencement, Morning Ceremony: College of Liberal Arts and Sciences, held June 15, 2014.

Lorry I. Lokey and Nicholas D. Kristof received honorary degrees; Kristof delivered the commencement address.

Community Level Impacts Associated With The Invasion Of English Ivy (Hedera Spp.) In Forest Park: A Look At The Impacts Of Ivy On Community Composition And Soil Moisture, Sara Rose Copp

Dissertations and Theses

Invasive species degrade ecosystems by altering natural processes and decreasing the abundance and diversity of native flora. Communities with major fluctuations in resource supply allow invasive species to exploit limiting resources making the community prone to invasion. In the Pacific Northwest, urban forests characterized with limited light and seasonally limited soil moisture are being dominated by nonnative English ivy (Hedera spp). Three observational studies were conducted in the Southern end of Forest Park within the Balch Creek Subwatershed in Portland, Oregon in order to understand 1) how English ivy changes over three growing seasons, 2) how the native …

Macroinvertebrates And Excessive Fine Sediment Conditions In Oregon Coastal Streams, Patrick M. Edwards

Dissertations and Theses

The Pacific Coastal ecoregion contains large tracts of economically important forest lands that also serve as critical stream habitat for endangered Salmonids. Excessive fine sediment deposition in streams of this region is a major environmental concern in the region but difficult to measure directly. The use of stream invertebrates to monitor fine sediment conditions in streams requires careful consideration of several important factors that complicate their use as bioindicators including high spatial and temporal variability and covariance with other environmental variables.

To evaluate the use of stream invertebrates as bioindicators of excessive fine sediment, three hypotheses were tested. The first …

Characterization Of Methylene Diphenyl Diisocyanate Protein Conjugates, Morgen Mhike

Dissertations and Theses

Diisocyanates (dNCO) such as methylene diphenyl diisocyanate (MDI) are used primarily as cross-linking agents in the production of polyurethane products such as paints, elastomers, coatings and adhesives, and are the most frequently reported cause of chemically induced immunologic sensitization and occupational asthma (OA). Immune mediated hypersensitivity reactions to dNCOs include allergic rhinitis, asthma, hypersensitivity pneumonitis and allergic contact dermatitis.

There is currently no simple diagnosis for the identification of dNCO asthma due to the variability of symptoms and uncertainty regarding the underlying mechanisms. Immunological sensitization due to dNCO exposure is traditionally thought to require initial conjugation of the dNCO to …

The Impact Of School-Level Factors On Minority Students' Performance In Ap Calculus, Phillip Bruce Pearson

Dissertations and Theses

In recent years, Science, Technology, Engineering, and Technology (STEM) talent pool has re-emerged as a national priority. Certain racial and ethnic groups are dramatically underrepresented in STEM careers and STEM educational programs, an especially serious concern given demographic transitions underway in the United States. The College Board's Advanced Placement (AP) Calculus program provides one way in which students can gain exposure to college-level mathematics while still in high school. This study analyzed factors that contribute to the success of minority students in AP Calculus using a large, longitudinal (2007-2012), geographically distributed dataset which included important school-level variables and AP scores …

Bridging The Future To Postsecondary Readiness, Brian Patrick Sien

Dissertations and Theses

Continuing education advances society. For every student, our educational system should provide a seamless transition from one level to the next until a degree or certificate is earned that reflects a mastery of skills needed to secure employment. This helps prepare each individual for a successful life after exiting the educational system and greatly benefit our society. Today, however, many students graduating from high schools are not ready for a postsecondary education. Transitioning students from high school to college is a complex process that requires many different approaches. Students making this transition are finding it more difficult to enter and …

Toward A Reliable Prediction Of Seasonal Forecast Uncertainty: Addressing Model And Initial Condition Uncertainty With Ensemble Data Assimilation And Sequential Bayesian Combination, Caleb Matthew Dechant, Hamid Moradkhani

Civil and Environmental Engineering Faculty Publications and Presentations

Uncertainties are an unfortunate yet inevitable part of any forecasting system. Within the context of seasonal hydrologic predictions, these uncertainties can be attributed to three causes: imperfect characterization of initial conditions, an incomplete knowledge of future climate and errors within computational models. This study proposes a method to account for all threes sources of uncertainty, providing a framework to reduce uncertainty and accurately convey persistent predictive uncertainty. In currently available forecast products, only a partial accounting of uncertainty is performed, with the focus primarily on meteorological forcing. For example, the Ensemble Streamflow Prediction (ESP) technique uses meteorological climatology to estimate …

Does Voluntary Reading Matter? The Influences Of Voluntary Reading On Student Achievement, Maika J. Yeigh

Dissertations and Theses

Does voluntary reading matter? While there is much known about the benefits to children who engage in sustained silent reading, commercial reading programs implemented as a result of No Child Left Behind often displace time for children to silently read (NCLB, 2002). An increase in the amount of time children spend with a commercial reading program has meant a decrease in time provided for in-school voluntary reading during the elementary literacy block (Brenner & Hiebert, 2010). This quantitative study used the 2011 restricted-use National Assessment of Educational Progress (NAEP) data to determine whether opportunities provided to children for in-school voluntary …

Examining Racial Disparities In Beaverton, Alexis D. R. Ball

Center to Advance Racial Equity Publications and Reports

Examining Racial Disparities in Beaverton aims to assist the City of Beaverton’s Diversity Advisory Board in understanding the current state of Beaverton’s communities of color as they work to create a “Diversity, Equity & Inclusion Plan.” It synthesizes and analyzes available data to describe racial disparities in Beaverton, Oregon through the use of raw data and secondary analysis, reports and communications from the City of Beaverton, and expert interviews. The presentation of data emphasizes a comparison of outcomes for communities of color and the white community with the purpose of highlighting common experiences across communities of color and demonstrating urgency …

Spontaneous Parametric Down-Conversion And Quantum Entanglement, Jesse Catalano

University Honors Theses

Quantum entanglement has been a topic of much research in modern physics, and an application in quantum computing is envisioned. This thesis address the use of polarization entangled photon pairs produced by spontaneous parametric down-conversion (SPDC) in entanglement transfer process and quantum computing. The simplicity of SPDC entanglement relative to other quantum phenomena is first emphasized by developing a complete classical theory of the photon-crystal interactions characteristic of SPDC. The methods of achieving polarization superposition via the Type-I and Type-II SPDC are described. A combination of superposition and polarization correlation between down-converted photons is shown to violate Bell’s inequality, thus …

The Community Economic Impacts Of Large Wildfires: A Case Study From Trinity County, California, Emily Jane Davis, Cassandra Moseley, Max Nielsen-Pincus, Pamela J. Jakes

Environmental Science and Management Faculty Publications and Presentations

Wildfires are increasing in severity and frequency in the American West, but there is limited understanding of their economic effects at the community level. We conducted a case study of the impacts of large wildfires in 2008 in Trinity County, California, by examining labor market, suppression spending, and qualitative interview data. We found that the 2008 fires had interrelated effects on several economic sectors in the county. Labor market data indicated a decrease in total private-sector employment and wages and an increase in public-sector employment and wages during the summer of 2008 compared to the previous year, while interviews captured …

Mapping Landscape Values: Issues, Challenges And Lessons Learned From Field Work On The Olympic Peninsula, Washington, Diane Besser, Rebecca J. Mclain, Lee Cerveny, Kelly Biedenweg, David Banis

Geography Faculty Publications and Presentations

In order to inform natural resource policy and land management decisions, landscape values mapping (LVM) is increasingly used to collect data about the meanings that people attach to places and the activities associated with those places. This type of mapping provides geographically referenced data on areas of high density of values or associated with different types of values. This article focuses on issues and challenges that commonly occur in LVM, drawing on lessons learned in the US Forest Service Olympic Peninsula Human Ecology Mapping Project. The discussion covers choosing a spatial scale for collecting data, creating the base map, developing …

An Eigenvector-Based Test For Local Stationarity Applied To Array Processing, Jorge Quijano, Lisa M. Zurk

Electrical and Computer Engineering Faculty Publications and Presentations

In sonar array processing, a challenging problem is the estimation of the data covariance matrix in the presence of moving targets in the water column, since the time interval of data local stationarity is limited. This work describes an eigenvector-based method for proper data segmentation into intervals that exhibit local stationarity, providing data-driven higher bounds for the number of snapshots available for computation of time-varying sample covariance matrices. Application of the test is illustrated with simulated data in a horizontal array for the detection of a quiet source in the presence of a loud interferer.

Wake Interaction And Power Production Of Variable Height Model Wind Farms, M. H. Vested, N. Hamilton, J. N. Sørensen, Raul Bayoan Cal

Mechanical and Materials Engineering Faculty Publications and Presentations

Understanding wake dynamics is an ongoing research topic in wind energy, since wakes have considerable effects on the power production when wind turbines are placed in a wind farm. Wind tunnel experiments have been conducted to study the wake to wake interaction in a model wind farm in tandem with measurements of the extracted power. The aim is to investigate how alternating mast height influences the interaction of the wakes and the power production. Via the use of stereo-particle image velocimetry, the flow field was obtained in the first and last rows of the wind turbine array as a basis …

Construction Of An Environmental Quality Index For Public Health Research, Lynne C. Messer, Jyotsna S. Jagai, Kristen M. Rappazzo, Danelle T. Lobdell

Community Health Faculty Publications and Presentations

Background

A more comprehensive estimate of environmental quality would improve our understanding of the relationship between environmental conditions and human health. An environmental quality index (EQI) for all counties in the U.S. was developed.

Methods

The EQI was developed in four parts: domain identification; data source acquisition; variable construction; and data reduction. Five environmental domains (air, water, land, built and sociodemographic) were recognized. Within each domain, data sources were identified; each was temporally (years 2000–2005) and geographically (county) restricted. Variables were constructed for each domain and assessed for missingness, collinearity, and normality. Domain-specific data reduction was accomplished using principal components …

Vanishing Configurations In Network Dynamics With Asynchronous Updates, Ian H. Dinwoodie

Mathematics and Statistics Faculty Publications and Presentations

We consider Boolean dynamics for biological networks where stochasticity is introduced through asynchronous updates. An exact method is given for finding states which can reach a steady state with positive probability, and a method is given for finding states which cannot reach other steady states. These methods are based on computational commutative algebra. The algorithms are applied to dynamics of a cell survival network to determine node assignments that exclude termination in a cancerous state

Supply Chain Risk Management In India: An Empirical Study Of Sourcing And Operations Disruptions, Their Frequency, Severity, Mitigation Methods, And Expectations, Andreas Udbye

Dissertations and Theses

With an annual growth of almost 20% since the year 2000, Indian merchandise exports exceeded 300 billion U.S. dollars in 2012. The country is becoming a major supplier to the world. However, companies sourcing products and operating in India are experiencing a variety of supply chain disruptions that impede their operations and finances. The purpose of this dissertation is to investigate the frequency, impact and severity of supply chain risks experienced by companies in India, as well as assess the usefulness of mitigation methods and enquire about future expected disruptions. It is hoped that the results will prepare managers to …

Subwavelength Visualization Of Light In Thin Film Waveguides With Photoelectrons, Joseph P. Fitzgerald, Robert Campbell Word, Rolf Könenkamp

Physics Faculty Publications and Presentations

We report the visualization and quantitative analysis of electromagnetic surface fields at solid surfaces with the potential for λ/50 resolution. To illustrate this capability, we investigate patterns in two-photon photoemission images of light-diffracting structures in waveguiding, transparent thin films. The obtained micrographs show interference patterns between incident and guided light with a remarkable sensitivity to subwavelength features. We demonstrate that photoemission rates are directly related to the surface field strengths and develop a subwavelength method to calculate the surface fields from optical properties and surface topology based on the two-dimensional Kirchhoff diffraction integral. Calculated images based on this theoretical approach …

Quantifying The Impacts Of Initial Condition And Model Uncertainty On Hydrological Forecasts, Caleb Matthew Dechant

Dissertations and Theses

Forecasts of hydrological information are vital for many of society's functions. Availability of water is a requirement for any civilization, and this necessitates quantitative estimates of water for effective resource management. The research in this dissertation will focus on the forecasting of hydrological quantities, with emphasis on times of anomalously low water availability, commonly referred to as droughts. Of particular focus is the quantification of uncertainty in hydrological forecasts, and the factors that affect that uncertainty. With this focus, Bayesian methods, including ensemble data assimilation and multi-model combinations, are utilized to develop a probabilistic forecasting system. This system is applied …

Design And Prototyping Of An Antenna-Coupled Cryotron, Shauna Jensen

Dissertations and Theses

Grid-scale integration of renewable energy sources and smart grid devices has created new demands in flexible power conversion. State-of-the-art semiconductor power switches present limitations in power handling capability, as well as forward and reverse breakdown voltages. Superconducting materials are a viable alternative due to their robustness against high ampacities, large electric fields and abrupt changes in power flow. This work pays focus to material testing and apparatus design for an antenna-coupled cryotron (ACC), which is a superconducting power switch.
Design, fabrication and testing are examined for a longitudinal resonant cavity, paired with monopole transmit and modified slot receive antennae. These …

Analytical Efficiencies Through The Integration Of Modeling And Simulation Tools, Steve Perone

PSU Transportation Seminars

Linking planning and operations is vital to improving transportation decision making and the overall effectiveness of transportation systems. In this seminar Steve will discuss data and modeling methods supported by the PTV Vision software suite to facilitate integrated planning for operations.

Adult Returning Students And Proportional Reasoning: Rich Experience And Emerging Mathematical Proficiency, Ann Sitomer

Dissertations and Theses

This study explores adult returning students' mathematical experience and ways of thinking prior to enrolling in a community college arithmetic review course. It further examines one student's experience of the course. The first part of the study documents everyday activities adult students perceive as mathematical using Bishop's pan-cultural mathematical activities (Bishop, 1994), and queries students' prior experience with mathematics in school. The second part examines students' ways of thinking about proportion prior to instruction, using a framework developed from previous research (e.g., Lamon, 1993). The third part of the study examines the interaction between informal ways of thinking about mathematics …

Agent-Based Control Of A Flapping Wing Micro Aerial Vehicle, Michal Podhradský

Student Research Symposium

Flapping wing micro aerial vehicles (FWMAVs) are biomimetic vehicles, because they imitate insects in the way they fly. FWMAVs are very small and highly manoeuvrable and can be used in reconnaissance, environmental monitoring, search & rescue, and other applications. The goal of the project is to develop & verify an agent based flight controller for FWMAV that can adapt to different flight conditions, actuator failures, and different vehicles while delivering constant performance. Agent based control was successfully applied in industry and distributed applications, but to our best knowledge never in an actual flying vehicle. Agent based control utilizes machine learning, …

Predicting The Optical Response Of A Generalized Multilayer Thin Film, A.J. Lawrence, Erik J. Sánchez

Student Research Symposium

The contrast mechanism in Kerr imaging is the apparent angle through which the plane of polarization is rotated upon reflection from a magnetic surface, and this can be calculated for a well characterized surface given the polarization state of the incident light. As in traditional optical microscopy, the spatial resolution is limited by diffraction to roughly half the wavelength of the illumination light. The diffraction limit can be circumvented through the use of near-field scanning optical microscopy, in which the illumination source is an evanescent field at the tip of a tapered optical fiber. The complication in merging these two …

Zinc Oxide Random Laser Threshold Enhancement Via Addition Of Passive Scatterers, Zachariah M. Peterson, Rolf Könenkamp, Robert Campbell Word

Student Research Symposium

Zinc oxide (ZnO) is a wide bandgap n-type semiconductor with a variety of optical and electrical applications and many methods of fabrication. Strong optical scattering and photoluminescence from ZnO nanoparticles and films makes the material an ideal candidate for a random laser. Previous studies have shown both incoherent and coherent random lasing from ZnO films and particles agglomerations. When used as a passive scatterer in a laser dye gain medium, the addition of ZnO has been shown to improve the threshold for lasing. By combining active scattering ZnO with a passive scatterer, MgO, we show here that the lasing threshold …