Digital Commons Network^™

Prebiotic Rna Network Formation: A Taxonomy Of Molecular Cooperation, Cole Mathis, Sanjay N. Ramprasad, Sara Imari Walker, Niles Lehman

Chemistry Faculty Publications and Presentations

Cooperation is essential for evolution of biological complexity. Recent work has shown game theoretic arguments, commonly used to model biological cooperation, can also illuminate the dynamics of chemical systems. Here we investigate the types of cooperation possible in a real RNA system based on the Azoarcusribozyme, by constructing a taxonomy of possible cooperative groups. We construct a computational model of this system to investigate the features of the real system promoting cooperation. We find triplet interactions among genotypes are intrinsically biased towards cooperation due to the particular distribution of catalytic rate constants measured empirically in the real system. For other …

Investigating Statistics Teachers' Knowledge Of Probability In The Context Of Hypothesis Testing, Jason Mark Asis Dolor

Dissertations and Theses

In the last three decades, there has been a significant growth in the number of undergraduate students taking introductory statistics. As a result, there is a need by universities and community colleges to find well-qualified instructors and graduate teaching assistants to teach the growing number of statistics courses. Unfortunately, research has shown that even teachers of introductory statistics struggle with concepts they are employed to teach. The data presented in this research sheds light on the statistical knowledge of graduate teaching assistants (GTAs) and community college instructors (CCIs) in the realm of probability by analyzing their work on surveys and …

Maximizing Profit Of Certification Services Provided By Nrtls, Bhawinee Banchongraksa, Chatchai Kubpiyajanya, Mufeed Yacoub, Tiffany Tran

Engineering and Technology Management Student Projects

Nationally Recognized Testing Laboratories (NRTLs) are independent third-party organizations recognized by the Occupational Safety & Health Administration (OSHA) to provide evaluation, testing and certification of products. All NRTLs conduct testing and certification are based on safety standards developed by organizations, such as Underwriters Laboratories (UL). In order to remain competitive in their respective markets, NRTLs must continually find new business lines to provide services to and maintain. NRTLs accomplish this goal by seeking out companies to which they can provide their certification services at a profit.

One of the biggest challenges NRTLs face in their annual operations, is finding a …

A Comparative Assessment Of Projected Meteorological And Hydrological Droughts: Elucidating The Role Of Temperature, Ali Ahmadalipour, Hamid Moradkhani, Mehmet C. Demirel

Civil and Environmental Engineering Faculty Publications and Presentations

The changing climate and the associated future increases in temperature are expected to have impacts on drought characteristics and hydrologic cycle. This paper investigates the projected changes in spatiotemporal characteristics of droughts and their future attributes over the Willamette River Basin (WRB) in the Pacific Northwest U.S. The analysis is performed using two subsets of downscaled CMIP5 global climate models (GCMs) each consisting of 10 models from two future scenarios (RCP4.5 and RCP8.5) for 30 years of historical period (1970–1999) and 90 years of future projections (2010–2099). Hydrologic modeling is conducted using the Precipitation Runoff Modeling System (PRMS) as a …

Random Walks On Digraphs, J.J.P. Veerman

Mathematics and Statistics Faculty Publications and Presentations

Let V = {1, · · · n} be a vertex set and S a non-negative row-stochastic matrix (i.e. rows sum to 1). V and S define a digraph G = G(V, S) and a directed graph Laplacian L as follows. If (S)ij > 0 (in what follows we will leave out the parentheses) there is a directed edge j → i. Thus the ith row of S identifies the edges coming into vertex i and their weights. This set of vertices are collectively the neighbors of i, and is denoted by Ni . The diagonal elements Sii are chosen such …

Elution Tailing Of Nonaqueous Phase Liquids In Porous Media, Louisa Orr

Civil and Environmental Engineering Undergraduate Honors Theses

A variety of porous media were studied to characterize contaminant dispersion over time. This work looked at a compilation of previously published studies to investigate the dependence of long term elution tailing trends on particular soil characteristics. Recession curve analysis was conducted on existing dispersed contaminant literature, to yield the low-concentration recession constant (K). The R² values correlating the soil properties to contaminant concentration ranged from 0.12494 to 0.95429. The low-concentration recession constant (K) values ranged from 0.9745407 0.9999988. The relationship between K and the soil properties porosity, organic carbon, and fines fraction is increasing. Bulk density and the …

Quantifying Resilience Of Multiple Ecosystem Services And Biodiversity In A Temperate Forest Landscape, Elena Cantarello, Adrian C. Newton, Phillip A. Martin, Paul M. Evans, Arjan Gosal, Melissa S. Lucash

Geography Faculty Publications and Presentations

Resilience is increasingly being considered as a new paradigm of forest management among scientists, practitioners, and policymakers. However, metrics of resilience to environmental change are lacking. Faced with novel disturbances, forests may be able to sustain existing ecosystem services and biodiversity by exhibiting resilience, or alternatively these attributes may undergo either a linear or nonlinear decline. Here we provide a novel quantitative approach for assessing forest resilience that focuses on three components of resilience, namely resistance, recovery, and net change, using a spatially explicit model of forest dynamics. Under the pulse set scenarios, we explored the resilience of nine ecosystem …

Optimizing Student Workforce Scheduling At Psu Office Of Information Technology (Oit), Agam Ebramsyah, Aishwarya Joy, Cody Miller, Jake Stevens, Priyanka Patil

Engineering and Technology Management Student Projects

A significant challenge for businesses of any size, is generating a work schedule that ensures adequate personnel coverage to ensure all aspects of the business are properly staffed, while preventing waste produced from having an excess number of employees working at a given time. The decision to manually create spreadsheets and work schedules that take into account availability, staffing requirements, and cost efficiency can become overwhelming and labor intensive. For Portland State University's Office of Information Technology (OIT), there is a significant challenge in scheduling student workers, while ensuring staffing requirements are met, student work hour restrictions are observed, and …

Organics To You - Optimization Of Produce Bins, Rassaniya Lerdphayakkarat, Chuan Chieh Lu, Jon Roschke, Juliana Suzuki, Jessie Truong

Engineering and Technology Management Student Projects

Organics to You (www.organicstoyou.org ) is a produce delivery company that focuses on bringing organic local food from local farms straight to the homes, schools, and businesses of its clients. Each week a "Small Bin" is created using different varieties of local produce from various farms. Customers receive a bin that contains 12-14 varieties of produce with 2-6 "servings" of each variety (e.g., 1 melon, 4 apples, 1 head of lettuce, 2 lbs potatoes, etc).

Our objective is to optimize the contents of the “Small Bin”. The decision we want to make is how much of each variety do …

Data Envelopment Analysis Using Glpkapi In R, Konrad Miziolek, Jordan Beary, Shreyas Vasanth, Surekha Chanamolu, Rudraxi Mitra

Engineering and Technology Management Student Projects

The work done here is primarily a wrapper function written to separate some of the more difficult-to-use glpkAPI functionality from the end-user. The user, when prompted, selects the appropriate configuration of the .mod file to the task (for example, output-oriented CRS), and the data file, as a .dat. The function then loads the required glpkAPI library, and carries forward the model. It allocates the problem and workspace, reads the model file and data file the user selects, builds the problem, and solves it. The function returns primal values, and, if dual = TRUE is selected, also returns dual weights.

Forest Collaborative Meeting Agenda, Addis Ababa, Ethiopia, Environment For Development (Efd) Initiative

Forest Collaborative Research

Agenda for the Environment for Development (EfD) Initiative Annual Meeting on 27-30 October 2017 at Capital Hotel, Addis Ababa, Ethiopia.

Hydrological Patterns And The Effects Of Land Use On Tss Concentrations And Yields In The Mccarthy Creek Watershed, Portland, Oregon, David Farmer

Environmental Science and Management Professional Master's Project Reports

The spread of impervious surface areas and the reduction of tree canopy via urbanization has numerous water quality impacts on Pacific Northwest watersheds. One such impact is elevated levels of Total Suspended Solids (TSS) in run-off during storm events, particularly in steep, forested watersheds undergoing urbanization. This project was developed in collaboration with the West Multnomah Soil and Water Conservation District and focused on the McCarthy Creek Watershed, as a case-study watershed located in Portland, OR. The study aimed to identify elevated TSS concentrations and yields during storm events on both mainstem and tributary sampling locations, establish the relationship between …

Johnson Creek Bacteria Tmdl Implementation: Status And Trend Analysis Study, John Gala

Environmental Science and Management Professional Master's Project Reports

Like many other waterbodies in the United States, Johnson Creek, a tributary of the Lower Willamette River is water quality limited for bacteria. Escherichia coli (E. coli), a member of the fecal coliform bacteria group, has been found to have a high association with human pathogens and the occurrences of gastrointestinal illnesses in waters used for contact recreation; E. coli is commonly used as an indicator of fecal contamination. In the State of Oregon water contact recreational standards for fecal exposure is assessed by measuring in stream levels of E. coli. Because Johnson Creek is water quality …

Formalizing The Panarchy Adaptive Cycle With The Cusp Catastrophe [Presentation], Martin Zwick, Joshua Hughes

Complex Systems Faculty Publications and Presentations

The panarchy adaptive cycle, a general model for change in natural and human systems, can be formalized by the cusp catastrophe of René Thom's topological theory. Both the adaptive cycle and the cusp catastrophe have been used to model ecological, economic, and social systems in which slow and small continuous changes in two control variables produce fast and large discontinuous changes in system behavior. The panarchy adaptive cycle, the more recent of the two models, has been used so far only for qualitative descriptions of typical dynamics of such systems. The cusp catastrophe, while also often employed qualitatively, is a …

Ideas And Graphs, Martin Zwick

Complex Systems Faculty Publications and Presentations

A graph can specify the skeletal structure of an idea, onto which meaning can be added by interpreting the structure.

This paper considers graphs (but not hypergraphs) consisting of four nodes, and suggests meanings that can be associated with several different directed and undirected graphs.

Drawing on Bennett's "systematics," specifically on the Tetrad that systematics offers as a model of 'activity,' the analysis here shows that the Tetrad is versatile model of problem-solving, regulation and control, and other processes.

Slides are available below.

Formalizing The Panarchy Adaptive Cycle With The Cusp Catastrophe, Martin Zwick, Joshua Hughes

Complex Systems Faculty Publications and Presentations

The panarchy adaptive cycle, a general model for change in natural and human systems, can be formalized by the cusp catastrophe of René Thom's topological theory. Both the adaptive cycle and the cusp catastrophe have been used to model ecological, economic, and social systems in which slow and small continuous changes in two control variables produce fast and large discontinuous changes in system behavior. The panarchy adaptive cycle, the more recent of the two models, has been used so far only for qualitative descriptions of typical dynamics of such systems. The cusp catastrophe, while also often employed qualitatively, is a …

Teaching "In Their Best Interest": Preservice Teachers' Narratives Regarding English Learners, Amanda T. Sugimoto, Kathy Carter, Kathleen J. Stoehr

Curriculum and Instruction Faculty Publications and Presentations

In the United States, teachers are increasingly working with English Learners (ELs) in mainstream classrooms. Several areas of focus have been proposed to guide the preparation of teachers for working with ELs, including: language related knowledge, skills, and dispositions. This narrative study examined how field-based experiences shaped 49 preservice teachers' dispositions toward ELs. An iterative and thematic analysis of collected narratives found that preservice teachers often completed their practicum in classrooms that did not model positive dispositions or pedagogical practices toward ELs. These findings have implications for the tasks and experiences given to preservice teachers during their preparation sequence.

“Our Greatest Songs Are Still Unsung”: Educating Citizens About Schooling In A Multicultural Society, Simona Goldin, Erin E. Flynn, Cori Mehan Egan

School of Social Work Faculty Publications and Presentations

This study examines how a practice-based unit informs undergraduates’ understandings of the dynamics of teaching and learning in a multicultural society, and how these intersect with equity in U.S. classrooms. Citizens’ nuanced understanding of teaching and learning is increasingly important for their engagement with U.S. schools. Practice-based opportunities can allow students to “see” the complexity of teaching and to challenge assumptions about teaching and learning, which are central to preparing an informed citizenry. Findings further suggest that a single course is not sufficient to expand undergraduate students’ understanding of the role of diversity in social life. More concentrated and ongoing …

Values Mapping And Counter-Mapping In Contested Landscapes: An Olympic Peninsula (Usa) Case Study, Rebecca J. Mclain, Lee Cerveny, Kelly Biedenweg, David Banis

Geography Faculty Publications and Presentations

Indigenous peoples, local communities, and other groups can use counter-mapping to make land claims, identify areas of desired access, or convey cultural values that diverge from the dominant paradigm. While sometimes created independently, counter-maps also can be formulated during public participation mapping events sponsored by natural resource planning agencies. Public participation mapping elicits values, uses, and meanings of landscapes from diverse stakeholders, yet individuals and advocacy groups can use the mapping process as an opportunity to make visible strongly held values and viewpoints. We present three cases from the Olympic Peninsula in Washington State to illustrate how stakeholders intentionally used …

Finding Water Scarcity Amid Abundance Using Human–Natural System Models, William K. Jaeger, Adell Amos, Daniel P. Bigelow, Heejun Chang, David R. Conklin, Roy Haggerty, Christian Langpap, Kathleen Moore, Philip Mote, Anne W. Nolin, Andrew J. Plantinga, Cynthia L. Schwartz, Desiree Tullos, David P. Turner

Geography Faculty Publications and Presentations

Water scarcity afflicts societies worldwide. Anticipating water shortages is vital because of water’s indispensable role in social-ecological systems. But the challenge is daunting due to heterogeneity, feedbacks, and water’s spatial-temporal sequencing throughout such systems. Regional system models with sufficient detail can help address this challenge. In our study, a detailed coupled human–natural system model of one such region identifies how climate change and socioeconomic growth will alter the availability and use of water in coming decades. Results demonstrate how water scarcity varies greatly across small distances and brief time periods, even in basins where water may be relatively abundant overall. …

Torrefaction Kinetics Of Hemp Hurds, An Emerging Agricultural Byproduct, In A Small Retort, Tel Jensen

Civil and Environmental Engineering Undergraduate Honors Theses

As knowledge concerning the consequences of unsustainable energy sources and agricultural practices grows, development of low-impact alternatives to both becomes more important. Sustainable sources of biomass offer solutions to both problems. This study characterized the reaction kinetics of torrefying an agricultural byproduct, the woody interior of hemp stems, or hurds. Torrefaction was carried out at 250 °C in small and simple retorts made of galvanized steel pipe. A first-order model most closely approximated the reaction. A sensitivity analysis was performed and the data was adjusted to correct for three potential sources of error, and regressed to find the best fit …

Controlling Water Exchange Kinetics And Improving Paracest Imaging, Jacqueline R. Slack

Dissertations and Theses

Generating MR image contrast from exogenous contrast media through chemical exchange saturation transfer (CEST) offers several exciting new possibilities, such as multicolored imaging, the interleaving of pre- and post-contrast images, and the potential to perform ratiometric metabolic imaging. The major limitation of the deployment of CEST imaging is the comparatively high detection limits of exogenous agents and particularly at the low B_¹ power levels required to meet SAR requirements. The large chemical shifts afforded by paramagnetic (paraCEST) agents permit more rapid exchange kinetics and therefore potentially more effective contrast agents. Despite comparatively large chemical shifts, many Ln³⁺ DOTA-tetraamide …

Improved Scoring Models For Semantic Image Retrieval Using Scene Graphs, Erik Timothy Conser

Dissertations and Theses

Image retrieval via a structured query is explored in Johnson, et al. [7]. The query is structured as a scene graph and a graphical model is generated from the scene graph's object, attribute, and relationship structure. Inference is performed on the graphical model with candidate images and the energy results are used to rank the best matches. In [7], scene graph objects that are not in the set of recognized objects are not represented in the graphical model. This work proposes and tests two approaches for modeling the unrecognized objects in order to leverage the attribute and relationship models to …

Refining Bounding-Box Regression For Object Localization, Naomi Lynn Dickerson

Dissertations and Theses

For the last several years, convolutional neural network (CNN) based object detection systems have used a regression technique to predict improved object bounding boxes based on an initial proposal using low-level image features extracted from the CNN. In spite of its prevalence, there is little critical analysis of bounding-box regression or in-depth performance evaluation. This thesis surveys an array of techniques and parameter settings in order to further optimize bounding-box regression and provide guidance for its implementation. I refute a claim regarding training procedure, and demonstrate the effectiveness of using principal component analysis to handle unwieldy numbers of features produced …

The Influence Of Recurrent Modes Of Climate Variability On The Occurrence Of Monthly Temperature Extremes Over South America, Paul C. Loikith, Judah Detzer, Carlos R. Mechoso, Huikyo Lee, Armineh Barkhordarian

Geography Faculty Publications and Presentations

The associations between extreme temperature months and four prominent modes of recurrent climate variability are examined over South America. Associations are computed as the percent of extreme temperature months concurrent with the upper and lower quartiles of the El Niño–Southern Oscillation (ENSO), the Atlantic Niño, the Pacific Decadal Oscillation (PDO), and the Southern Annular Mode (SAM) index distributions, stratified by season. The relationship is strongest for ENSO, with nearly every extreme temperature month concurrent with the upper or lower quartiles of its distribution in portions of northwestern South America during some seasons. The likelihood of extreme warm temperatures is enhanced …

How Does A Next Generation Science Standard Aligned, Inquiry Based, Science Unit Impact Student Achievement Of Science Practices And Student Science Efficacy In An Elementary Classroom?, Kayla Lee Whittington

Dissertations and Theses

This study examined the impact of an inquiry based Next Generation Science Standard aligned science unit on elementary students' understanding and application of the eight Science and Engineering Practices and their relation in building student problem solving skills. The study involved 44 second grade students and three participating classroom teachers. The treatment consisted of a school district developed Second Grade Earth Science unit: What is happening to our playground? that was taught at the beginning of the school year. Quantitative results from a Likert type scale pre and post survey and from student content knowledge assessments showed growth in student …

Turbidity Dynamics During High-Flow Storm Events In The Clackamas River, Oregon 2006-2012, Micelis Clyde Doyle

Dissertations and Theses

Turbidity is a useful parameter that can be utilized to help understand the water quality in a river and is an expression of the optical properties of a liquid that cause light rays to be scattered and absorbed rather than transmitted in straight lines. A total of 41 storm events occurring during water years 2006-2012 were analyzed for this study. A hysteresis index (HI) was used to assess the difference in turbidity on the rising and falling limbs of a storm-hydrograph. The upstream Carter Bridge site exhibited a clockwise (C) hysteresis in 38 of 41 storm events and counter-clockwise (CC) …

Toxicant Formation In Dabbing: The Terpene Story, Jiries Meehan-Attrash, Wentai Luo, Robert M. Strongin

Chemistry Faculty Publications and Presentations

Inhalable, noncombustible cannabis products are playing a central role in the expansion of the medical and recreational use of cannabis. In particular, the practice of “dabbing” with butane hash oil has emerged with great popularity in states that have legalized cannabis. Despite their growing popularity, the degradation product profiles of these new products have not been extensively investigated. The study herein focuses on the chemistry of myrcene and other common terpenes found in cannabis extracts. Methacrolein, benzene, and several other products of concern to human health were formed under the conditions that simulated realworld dabbing. The terpene degradation products observed …

The 2016 Presidential Election: Demographic Transformation And Racial Backlash, Skyler Lillian Brocker-Knapp

Dissertations and Theses

Despite analysts' predictions and assertions prior to the 2016 presidential election, the Hispanic vote did not prove decisive. Donald Trump's victory elucidates a new electoral calculus, one that will be ruled simultaneously by changing demographics and the backlash against such change. While Hispanic voters largely supported Hillary Clinton, structural and individual impediments hinder their access to the voting booth and their turnout on election day. This thesis explores the reasons why the Hispanic electorate did not prove decisive in the 2016 presidential election. It further illuminates the changing Electoral College map, in which the Midwest and the Rustbelt are determined …

Filtered Subspace Iteration For Selfadjoint Operators, Jay Gopalakrishnan, Luka Grubišić, Jeffrey S. Ovall

Portland Institute for Computational Science Publications

We consider the problem of computing a cluster of eigenvalues (and its associated eigenspace) of a (possibly unbounded) selfadjoint operator in a Hilbert space. A rational function of the operator is constructed such that the eigenspace of interest is its dominant eigenspace, and a subspace iteration procedure is used to approximate this eigenspace. The computed space is then used to obtain approximations of the eigenvalues of interest. An eigenvalue and eigenspace convergence analysis that considers both iteration error and dis- cretization error is provided. A realization of the proposed approach for a model second-order elliptic operator is based on a …