Digital Commons Network^™

Naturally Occurring Background Levels Of Arsenic In The Soils Of Southwestern Oregon, Heather Ann Hurtado

Dissertations and Theses

This study examines the natural background concentrations of arsenic in the soils of southwest Oregon, using new samples in addition to data collected from previous theses (Khandoker, 1997 and Douglas, 1999). The original 213 samples were run by ICP-AES with a reporting limit of 20 ppm, and only three samples had detected values. The original samples were tested again (2013) at a lower reporting limit of 0.2 ppm by ICP-MS, as were 42 new samples (2013), to better ascertain the natural levels of arsenic in undisturbed soils. The aim is to add to the existing DEQ data set, which has …

Automatic Fault Injection For Driver Robustness Testing, Kai Cong, Li Lei, Zhenkun Yang, Fei Xie

Computer Science Faculty Publications and Presentations

Robustness testing is a crucial stage in the device driver development cycle. To accelerate driver robustness testing, effective fault scenarios need to be generated and injected without requiring much time and human effort. In this pa- per, we present a practical approach to automatic runtime generation and injection of fault scenarios for driver robust- ness testing. We identify target functions that can fail from runtime execution traces, generate effective fault scenarios on these target functions using a bounded trace-based it- erative strategy, and inject the generated fault scenarios at runtime to test driver robustness using a permutation-based injection mechanism. We …

Rock Creek Restoration Macroinvertebrate Monitoring Report, Daniel Bedell

Environmental Science and Management Professional Master's Project Reports

Stream restoration is widely used to rebuild habitat for native fisheries, but it is not well understood how current habitat reconstruction practices affect biological diversity. Citizen Science programs have potential to provide supplemental macroinvertebrate data for effectiveness monitoring of reach-scale restoration projects but variability in training, experience and collection methods can make interpretation difficult. The Clackamas Water Environment Services Watershed Health Education Program (WHEP) is an example of a Citizen Science-based program actively collecting biological data from restored streams. The purpose of this project was to use WHEP student-collected data to detect benthic macroinvertebrate community responses to stream restoration practices. …

A Written Instrument For Assessing Students’ Units Coordination Structures, Anderson Norton, Steven Boyce, Nathan Phillips, Tessa Anwyll, Catherine Ulrich, Jesse L. M. Wilkins

Mathematics and Statistics Faculty Publications and Presentations

Units coordination refers to students’ abilities to create units and maintain their relationships with other units that they contain or constitute. In recent research, units coordination has arisen as a key construct that mediates opportunities for student learning across several domains of mathematics, including fractions knowledge and algebraic reasoning. To date, assessments of students’ stages of units coordinating ability have relied upon clinical interviews or teaching experiments whose time-intensive nature precludes opportunities for conducting large-scale studies. We introduce a written instrument that teachers and researchers can use with large populations of students. We report on the reliability and validity of …

A Posteriori Eigenvalue Error Estimation For The Schrödinger Operator With The Inverse Square Potential, Hengguang Li, Jeffrey S. Ovall

Mathematics and Statistics Faculty Publications and Presentations

We develop an a posteriori error estimate of hierarchical type for Dirichlet eigenvalue problems of the form (−∆ + (c/r) 2 )ψ = λψ on bounded domains Ω, where r is the distance to the origin, which is assumed to be in Ω. This error estimate is proven to be asymptotically identical to the eigenvalue approximation error on a family of geometrically-graded meshes. Numerical experiments demonstrate this asymptotic exactness in practice.

Empirical Evidence For The Scale Dependence Of Biotic Interactions, Jonathan Belmaker, Phoebe Zarnetske, Sara Zonneveld, Sydne Record, Angela L. Strecker, Lydia Beaudrot

Environmental Science and Management Faculty Publications and Presentations

Aim: Although it is recognized that ecological patterns are scale dependent, the exact scales over which specific ecological processes operate are still a matter of controversy. In particular, understanding the scales over which biotic interactions operate is critical for predicting changes in species distributions in the face of the ongoing biodiversity crisis. It has been hypothesized that biotic interactions operate predominately at fine grains, yet this conjecture has received relatively little empirical scrutiny. We use US woodpeckers as a model system to assess the relative importance of biotic interactions, environmental suitability and geographic proximity to other intraspecific occurrence sites, …

Hydrophobic Surfactant Proteins Strongly Induce Negative Curvature, Mariya Chavarha, Ryan W. Loney, Shankar B. Rananavare, Stephen B. Hall

Chemistry Faculty Publications and Presentations

The hydrophobic surfactant proteins SP-B and SP-C greatly accelerate the adsorption of vesicles containing the surfactant lipids to form a film that lowers the surface tension of the air/water interface in the lungs. Pulmonary surfactant enters the interface by a process analogous to the fusion of two vesicles. As with fusion, several factors affect adsorption according to how they alter the curvature of lipid leaflets, suggesting that adsorption proceeds via a rate-limiting structure with negative curvature, in which the hydrophilic face of the phospholipid leaflets is concave. In the studies reported here, we tested whether the surfactant proteins might promote …

Enhancing Freshman Engineering Instruction With In-Class Interaction Systems And E-Books, Branimir Pejcinovic, Phillip K. Wong

Electrical and Computer Engineering Faculty Publications and Presentations

Electrical engineering students in our department take a year-long series of courses which introduces electrical engineering as a discipline and provides good grounding in engineering problem solving and programing. We have recently attempted to make the second course in the sequence more engaging by applying active learning techniques, including assigned reading and exercises prior to lectures, in-class exercises using a classroom interaction system, and programming exercises during lectures. Our results are mixed: while we think that students have learned more than if we had not used these techniques, we have not completely won over our students. While using an e-book …

Prediction -- The Quintessential Policy Model Validation Test, Wayne Wakeland

Complex Systems Faculty Publications and Presentations

It is essential to objectively test how well policy models predict real world behavior. The method used to support this assertion involves the review of three SD policy models emphasizing the degree to which the model was able to fit the historical outcome data and how well model-predicted outcomes matched real world outcomes as they unfolded. Findings indicate that while historical model agreement is a favorable indication of model validity, the act of making predictions without knowing the actual data, and comparing these predictions to actual data, can reveal model weaknesses that might be overlooked when all of the available …

A Tent Pitching Scheme Motivated By Friedrichs Theory, Jay Gopalakrishnan, Peter Monk, Paulina Sepulveda

Mathematics and Statistics Faculty Publications and Presentations

Certain Friedrichs systems can be posed on Hilbert spaces normed with a graph norm. Functions in such spaces arising from advective problems are found to have traces with a weak continuity property at points where the inflow and outflow boundaries meet. Motivated by this continuity property, an explicit space-time finite element scheme of the tent pitching type, with spaces that conform to the continuity property, is designed. Numerical results for a model one-dimensional wave propagation problem are presented.

Development And Uses Of Iterative Systematic Literature Reviews In Electrical Engineering Education, Branimir Pejcinovic

Electrical and Computer Engineering Faculty Publications and Presentations

It is expected that most, if not all, graduate students will posses skills necessary for doing literature reviews. It is less clear how to teach these skills most effectively especially to students who are area novices and unfamiliar with review process. Systematic literature reviews offer a solid instructional framework which can be implemented across curriculum and offer an opportunity to teach course material differently so that student learn not just the literature review technique itself but also some segment of the course material. Our pilot study investigated issues related to practical implementation of systematic literature reviews in two classes, with …

Defining The Terroir Of The Columbia Gorge Wine Region, Oregon And Washington, Usa Using Geographic Information Systems (Gis), Hilary Whitney

Dissertations and Theses

The Columbia Gorge Wine Region (CGWR) is an emerging wine producing area that extends for about 100km along the Columbia River in Oregon and Washington State in which the number of vineyards, wineries and physical terroir conditions have yet to be defined. To better understand the physical factors affecting Oregon and Washington wine, this project analyzes climate, topography, geology and soil at vineyards in the CGWR. This was accomplished using Geographic Information Systems, existing earth science databases and field work. The region, which includes the Columbia Gorge American Viticulture Area (AVA) and the southwest portion of the Columbia Valley AVA, …

Portland Spectrum, June 2015, Portland State University. Student Publications Board

Portland Spectrum

Editor: Corinne Hutfilz

Articles in this issue include: 25 Years of ADA; A Superhuman Future with Nanotechnology; Accountability Now; Literacy in the Information Age; The Right to Preach on College Campus; Got Gas; Higher One at High Risk; Two Sides of the Same Coin: Disparity Between American Aid Organizations; Up, Up, and Away: Superhero Movies are Just Getting Started; and ASPSU Election Recap

Time-Variant Load Models Of Electric Vehicle Chargers, Nicole P. Zimmerman

Dissertations and Theses

In power distribution system planning, it is essential to understand the impacts that electric vehicles (EVs), and the non-linear, time-variant loading profiles associated with their charging units, may have on power distribution networks. This research presents a design methodology for the creation of both analytical and behavioral models for EV charging units within a VHDL-AMS simulation environment.

Voltage and current data collected from Electric Avenue, located on the Portland State University campus, were used to create harmonic profiles of the EV charging units at the site. From these profiles, generalized models for both single-phase (Level 2) and three-phase (Level 3) …

Focus On A Stem, Based In Place, Watershed Curriculum: A Confluence Of Stormwater, Humans, Knowledge, Attitudes, And Skills, Lecia Molineux Schall

Dissertations and Theses

This case study investigated the potential of a place-based watershed curriculum, using STEM principles, to increase watershed literacy and knowledge of human impacts on stormwater in the environment. A secondary goal was to examine whether the place-based connection and increased exposure to issues within their local watershed impacted the students' environmental attitudes and sense of place. Over 500 sixth graders participated in this localized curriculum, where they learned the science behind watershed issues on their own school campuses. They focused on ways humans can monitor and mitigate their impacts on stormwater, through engineering investigations. The mixed-method research study investigated the …

Device, Method, And Algorithm To Assess Changes In Cardiac Output Via Intracardiac Impedance Monitoring, Geoffrey Fredrick Schau

Dissertations and Theses

Cardiac output, the volume of blood pumped by the heart over time, is a powerful clinical metric used by physicians to assess overall cardiac health and patient well-being. However, current cardiac output estimation methods are typically invasive, time-consuming, expensive, or some combination of all three. Patients that receive artificial cardiac pacemaker devices are particularly susceptible to cardiac dysfunction and often require long-term cardiac monitoring support.

This thesis proposes a novel cardiac output monitoring solution which leverages an implantable intracardiac medical device. The principles of traditional impedance cardiography, an established cardiac output monitoring technique in practice for over fifty years, have …

On Stochastic Comparisons Of Largest Order Statistics In The Scale Model, Subhash C. Kochar, Nuria Torrado

Mathematics and Statistics Faculty Publications and Presentations

Let X-lambda 1, X-lambda 2, ... ,X-lambda n be independent non negative random variables with X-lambda i similar to F(lambda(i)t), i = 1, ... , n, where lambda(i) > 0, i = 1, ... , n and F is an absolutely continuous distribution. It is shown that, under some conditions, one largest order statistic X-n:n(lambda) n is smaller than another one X-n:n(theta) according to likelihood ratio ordering. Furthermore, we apply these results when F is a generalized gamma distribution which includes Weibull, gamma and exponential random variables as special cases.

Improved Gain Stability Of A Digital Imager Using A Charge Feedback Amplifier, Elliot Eckman Mylott

Dissertations and Theses

Digital imagers including Charge-Coupled Devices (CCD) are essential to most forms of modern photographic technologies. The quality of the data produced by digital imagers have made them an invaluable scientific measurement tool. Despite the numerous advantages of digital imagers, there are still factors that limit their performance. One such factor is the stability of the camera's gain, the ratio that dictates the imager's ability to convert incident photons to a measurable output voltage. Variations in gain can affect the linearity of the device and produce inaccurate measurements.

One of the factors that determines the gain of the camera is the …

Women In Philosophy: A Qualitative Assessment Of Experiences At The Undergraduate Level, Crystal Nicole Lilith Aymelek

PSU McNair Scholars Online Journal

The underrepresentation of women in the field of philosophy has been a major concern for women in the discipline for at least the past ten years, and is increasingly gaining attention within academia. Current research at the undergraduate level suggests male and female enrollment occurs in relatively proportionate numbers in introductory philosophy courses but women’s enrollment dramatically decreases with the progression to upper division courses (Paxton, Figdor & Tiberius, 2012). To date, very little research has focused on the experiences of women philosophy majors at the undergraduate level. The present study conducted in-depth interviews with women who were either senior …

Exploratory Data Modeling Of Traumatic Brain Injury, Martin Zwick

Complex Systems Faculty Publications and Presentations

A short presentation of an analysis of data from Dr. Megan Preece on traumatic brain injury, the first in a series of planned secondary analyses of multiple TBI data sets. The analysis employs the systems methodology of reconstructability analysis (RA), utilizing both variable- and state-based and both neutral and directed models. The presentation explains RA and illustrates the results it can obtain. Unlike the confirmatory approach standard to most data analyses, this methodology is designed for exploratory modeling. It thus allows the discovery of unanticipated associations among variables, including multi-variable interaction effects of unknown form. It offers the opportunity for …

Investigations Of The Air-Water Interface: A Structural Analysis Of Metallic Surface Films And Aquatic Surface Films By Comparative Microscopy, Randall William Smith

Dissertations and Theses

The air-water interface is an important natural boundary layer that has been neglected as an area of environmental field research. This study establishes that comparative microscopy can be an effective environmental method, and establishes that the term metallic surface films, is a more accurate descriptor than iron oxide surface films. This research shows that surface films are complex, often with layered structure, serve as habitat for significant biota, and act as a point of mineralization to several transition metal elements including manganese, iron, copper, nickel and zinc. This study demonstrates that surface films form under several conditions and can have …

Localized Ecological And Educational Effects Of Environmental Service-Learning In Portland, Oregon, Steven Matthew Braun

Dissertations and Theses

Environmental service-learning is an intentional educational experience(s) wherein learners engage in meaningful activities designed to serve the environment. Environmental service-learning activities vary according to their learning and service goals and include ecomanagement, persuasion, legal action, economic action and political action. The purpose of this mixed methods research was to explore the ecological and educational impacts of grades 6-12 environmental education, with special attention to environmental service-learning throughout Portland, Oregon.

Ecological impacts considered restoration and conservation outcomes of several environmental service-learning programs including plant communities, soils, litter removal and trail maintenance. Educational outcomes considered aspects of environmental literacy including locus of …

Gifted Black And Biracial Students At A Predominantly White Gifted School, Clair Elizabeth Pople

Dissertations and Theses

The underrepresentation of gifted Black and Biracial students is a pervasive problem in and of itself, and indicates a much larger struggle of disproportionality of Black and Biracial students who are not called upon or supported in efforts to meet their academic potential. Therefore, an evaluation of the inequity generated by gifted education is warranted. It is true that the majority of gifted programs are often predominantly White. Accordingly, Black and Biracial students who qualify for gifted programs may face unique challenges in their development of racial identity and their socio-emotional health.

Using ethnographic techniques, this case study explored the …

Revealing Structural Organization With Liquid Crystal-Based Spectral Imaging Polarimetry, James Campbell Gladish

Dissertations and Theses

Structural organization refers to the particular ordering of scatterers. Probing structural organization by imaging polarized spectral scatter provides insight into the composition of a medium, and can aid in remote sensing, the identification of tissue pathologies, and material characterization and differentiation. The vector nature of polarized light enables it to interact with optical anisotropies within a medium, while the spectral aspect of polarization is sensitive to small-scale structure. However, many polarization studies have limitations, as they provide qualitative image analysis, incomplete anisotropy information, or both. The ability to image the effects of anisotropy and small-scale structure at multiple wavelengths is …

Post-Silicon Functional Validation With Virtual Prototypes, Kai Cong

Dissertations and Theses

Post-silicon validation has become a critical stage in the system-on-chip (SoC) development cycle, driven by increasing design complexity, higher level of integration and decreasing time-to-market. According to recent reports, post-silicon validation effort comprises more than 50% of the overall development effort of an 65nm SoC. Though post-silicon validation covers many aspects ranging from electronic properties of hardware to performance and power consumption of whole systems, a central task remains validating functional correctness of both hardware and its integration with software. There are several key challenges to achieving accelerated and low-cost post-silicon functional validation. First, there is only limited silicon observability …

Staying On Script: Sexual Scripts And Sex Education, Elizabeth Carol Hauck

Dissertations and Theses

Existing research suggests that men and women develop differing sexual scripts that influence their behavior, interactions and emotions regarding sex. The objective of this project is to examine the experiences of men and women with formal sex education programs, especially in regards to information about: anatomy and biology, sexual responsibility and risk taking, sexual desire, virginity and abstinence, as well as to explore sources of sex education outside of school. Several studies suggest masculine sexual scripts dictate that men generally construct a more body-focused approach to sex, with an emphasis on competition, aggression and achievement. Conversely, emphasized feminine sexual scripts …

Stem Education In The Foreign Language Classroom With Special Attention To The L2 German Classroom, Sarah Danielle Schoettler

Dissertations and Theses

This thesis tackles the issues of foreign language education, with special attention to German as a foreign language, and STEM education in the K-12, and in some cases K-16, educational system. After exploring the societal and national need for improved STEM and foreign language education programs, this thesis suggests methods of integrating STEM education elements and principals in the foreign language classroom. These methods are provided in chapters about integrating state and national education standards in the STEM fields, core academic subject fields, and foreign language teaching, and finally in chapters about the most appropriate and effective pedagogies for successful …

Novel Methods For Learning And Adaptation In Chemical Reaction Networks, Peter Banda

Dissertations and Theses

State-of-the-art biochemical systems for medical applications and chemical computing are application-specific and cannot be re-programmed or trained once fabricated. The implementation of adaptive biochemical systems that would offer flexibility through programmability and autonomous adaptation faces major challenges because of the large number of required chemical species as well as the timing-sensitive feedback loops required for learning. Currently, biochemistry lacks a systems vision on how the user-level programming interface and abstraction with a subsequent translation to chemistry should look like. By developing adaptation in chemistry, we could replace multiple hard-wired systems with a single programmable template that can be (re)trained to …

An Investigation Of The Role Of Alternate Numeration Systems In Preservice Teacher Mathematics Content Courses, Jodi I. Fasteen

Dissertations and Theses

Alternate numeration systems are common in preservice teacher (PST) mathematics curricula, but there is limited research on how to leverage alternate systems to promote the development of mathematical knowledge for teaching. I analyzed the role of alternate numeration systems in three ways. I conducted a thematic analysis of current PST textbooks to consider the role of alternate numeration systems in written curricula. I conducted a teaching experiment to analyze PSTs' mathematical activity as they engaged with a base five task sequence to reinvent an algorithm for multiplication. And I introduced problematizing mathematical contexts as a design heuristic, situating this within …

Hardware/Software Interface Assurance With Conformance Checking, Li Lei

Dissertations and Theses

Hardware/Software (HW/SW) interfaces are pervasive in modern computer systems. Most of HW/SW interfaces are implemented by devices and their device drivers. Unfortunately, HW/SW interfaces are unreliable and insecure due to their intrinsic complexity and error-prone nature. Moreover, assuring HW/SW interface reliability and security is challenging. First, at the post-silicon validation stage, HW/SW integration validation is largely an ad-hoc and time-consuming process. Second, at the system deployment stage, transient hardware failures and malicious attacks make HW/SW interfaces vulnerable even after intensive testing and validation. In this dissertation, we present a comprehensive solution for HW/SW interface assurance over the system life cycle. …