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The Discontinuous Petrov–Galerkin Method
No full textThe discontinuous Petrov–Galerkin (DPG) method is a Petrov–Galerkin finite element method with test functions designed for obtaining stability. These test functions are computable locally, element by element, and are motivated by optimal test functions which attain the supremum in an inf-sup condition. A profound consequence of the use of nearly optimal test functions is that the DPG method can inherit the stability of the (undiscretized) variational formulation, be it coercive or not. This paper combines a presentation of the fundamentals of the DPG ideas with a review of the ongoing research on theory and applications of the DPG methodology. The scope of the presented theory is restricted to linear problems on Hilbert spaces, but pointers to extensions are provided. Multiple viewpoints to the basic theory are provided. They show that the DPG method is equivalent to a method which minimizes a residual in a dual norm, as well as to a mixed method where one solution component is an approximate error representation function. Being a residual minimization method, the DPG method yields Hermitian positive definite stiffness matrix systems even for non-self-adjoint boundary value problems. Having a built-in error representation, the method has the out-of-the-box feature that it can immediately be used in automatic adaptive algorithms. Contrary to standard Galerkin methods, which are uninformed about test and trial norms, the DPG method must be equipped with a concrete test norm which enters the computations. Of particular interest are variational formulations in which one can tailor the norm to obtain robust stability. Key techniques to rigorously prove convergence of DPG schemes, including construction of Fortin operators, which in the DPG case can be done element by element, are discussed in detail. Pointers to open frontiers are presented
Combined Passive and Active Ultrasonic Stress Wave Monitoring of a Full-Scale Laboratory Reinforced Concrete Bridge Column Subject to Reverse-Cyclic Lateral Loading
No full textEffective monitoring of reinforced concrete structures requires techniques that detect early-stage material change and active, localized cracking. This study investigates a combined structural health monitoring approach using passive acoustic emission and active ultrasonic methods on a full-scale reinforced concrete bridge column subjected to reverse-cyclic lateral loading. Active monitoring, based on coda wave interferometry, was used to track changes in wave velocity and waveforms, while passive acoustic emission monitoring was used to detect crack activity. The instrumentation consisted of three embedded ultrasonic transducers and three surface-mounted acoustic emission sensors. The results show that active ultrasonic monitoring is most effective prior to visual damage, successfully detecting the onset of internal cracking via wave velocity decreases exceeding 0.4%, and distinguishing load-induced effects from permanent damage. However, its utility diminished in later stages of damage progression, as strong signal decorrelation hindered further data interpretation. Additionally, active US measurements allowed a comparison of damage severity in different parts of the column. Conversely, passive acoustic emission monitoring effectively tracked the formation of concrete cracks throughout the experiment, with distinct event clusters and high-amplitude signals (\u3e 60 dB) confirming ongoing fracture processes in all damage states. This study confirms that combining these methods results in a more robust structural health monitoring strategy by leveraging their complementary strengths. Active techniques excel at tracking continuous material changes in early damage states, while passive methods are superior for detecting discrete cracking events as damage progresses. Importantly, both methods can utilize the same measurement equipment, enabling a cost-effective approach to continuous damage tracking
The First Thirty Years of Green Stormwater Infrastructure in Portland, Oregon
No full textOver the past 30 years, the City of Portland, Oregon, USA, has emerged as a national leader in green stormwater infrastructure (GSI). The initial impetus for implementing sustainable stormwater infrastructure in Portland stemmed from concerns about flooding and water quality in the city’s two major rivers, the Columbia and the Willamette. Heavy rainfall often led to combined sewer overflows, significantly polluting these waterways. A partial solution was the construction of “The Big Pipe” project, a large-scale stormwater containment system designed to filter and regulate overflow. However, Portland has taken a more comprehensive and long-term approach by integrating sustainable stormwater management into urban planning. Over the past three decades, the city has successfully implemented GSI to mitigate these challenges. Low-impact development strategies, such as bioswales, green streets, and permeable surfaces, have been widely adopted in streetscapes, pathways, and parking areas, enhancing both environmental resilience and urban livability. This perspective highlights the history of the implementation of Portland’s GSI programs, current design and performance standards, and challenges and lessons learned throughout Portland’s recent history. Innovative approaches to managing runoff have not only improved stormwater control but also enhanced green spaces and contributed to the city’s overall climate resilience while addressing economic well-being and social equity. Portland’s success is a result of strong policy support, effective integration of green and gray infrastructure, and active community involvement. As climate change intensifies, cities need holistic, adaptive, and community-centered approaches to urban stormwater management. Portland’s experience offers valuable insights for cities seeking to expand their GSI amid growing concerns about climate resilience, equity, and aging infrastructure
A New Approach to Probabilistic County Population Forecasting with an Example Application to West Texas
No full textThis paper shows how measures of uncertainty can be applied to existing subnational population forecasts using the 107 counties that make up West Texas as a case study. The measures of forecast uncertainty are relatively easy to calculate and meet several important criteria routinely applied by state and local demographers. We also report the results of two independent comparisons supporting the argument that our approach is valid. The paper concludes it is well-suited for developing probabilistic population forecasts in the United States and elsewhere
Optimizing Boys\u27 Motivation Over the Transition to Middle School: A Pattern-Centered Approach to Identifying Boys\u27 Profiles of Engagement and the Interpersonal Resources Important in Supporting Optimal Engagement of Boys Across Sixth Grade
No full textThere are normative declines in student engagement during the transition to middle school, and studies indicate that these challenges may be especially problematic for boys. Given the limited empirical evidence offering ways to support boys\u27 motivation, the main goal of this study was to understand ways we can help boys reach their full potential over the transition to middle school by examining the interpersonal resources from parents, teachers, and peers that sustain boys\u27 optimal engagement across the first year of middle school. Using data from an existing longitudinal dataset of 191 sixth-grade boys (N = 366; 52% male) in America, this study aimed to answer three main questions: (1) Which interpersonal resources in fall are connected to boys\u27 engagement concurrently, and predict changes in their engagement across the sixth-grade year? Results showed that although many teacher, parent, and peer resources were correlated with boys\u27 engagement, fewer were significant predictors of changes in boys\u27 overall engagement, or its behavioral and emotional dimensions separately. Most important were parent resources (involvement, structure (marginal), autonomy support, and their aggregate; and relatedness to father) and peer resources (group engagement and an aggregate of all peer resources). Teacher resources as an aggregate were predictors only of changes in behavior engagement (and only at a marginal level). (2) Can distinct subgroups of boys with similar levels of and changes in engagement be created, and can a subgroup of boys be identified who were motivationally strong across sixth grade? Seven profiles of engagement were created using tertile splits of mean levels of engagement (i.e., low, medium, high) in fall and in spring using cut-offs from the whole sample (including girls and boys), and combining the two smallest groups similar in initial levels of engagement and in direction of engagement changes. One group, with a High-High profile, included boys who were motivationally strong; they showed levels of engagement that were just as high as girls in the top tertile in both fall and spring, and maintained these high levels across the school year. (3) Do boys with optimal profiles of engagement differ from boys with other profiles in average levels of the interpersonal resources they experience in fall and in spring of sixth grade and do they differ from all boys in changes in interpersonal resources across the school year? Results showed that boys in the optimal group were higher in most interpersonal resources than many of the other groups in fall, especially in teacher and peer resources (reciprocated friendships and peer engagement). And although the optimal group experienced many of the same losses in resources as all boys, they maintained high levels for some, especially parent resources. Findings from this research informs home and school practices in promoting optimal engagement of boys, especially during the first year of middle school, and pinpoints levers of intervention aimed at improving the engagement of boys who struggle in school
Latino Threat Perceptions and Immigration Attitudes: An Examination Across Generations of Latinos
No full textRecently, immigration has been a major focus in U.S. politics, more importantly with the current administration pushing for the implementation of punitive immigration policies. Research shows that perceived Latino threat is associated with support Trump and harsh border controls. While existing research has expanded the perceived Latino threat and punitive border control attitudes among non-Latinos, less is known about how perceived Latino threat and punitive border control attitudes function within their own group and how they might vary across different generations of Latinos. Accordingly, there has been a shift in Latino voting preferences, specifically across different generations of Latinos. Research polls has found that generations that have remained in the United States the longest showed support for Trump in 2016, more compared to first-generation Latinos. Using primary national data from a survey sample of Latinos (N = 289) living in the United States, this study aims to expand prior work by analyzing perceived Latino threat and punitive border control attitudes within the Latino community. Findings from the study show that there is no relationship between respondents who identify as first-generation Latino and perceived Latino threat. First-generation Latinos reported lower levels of punitiveness, however when accounting for Latino identity and immigrant prejudice, they are no longer significant. Moreover, respondents who identify as second-generation Latino reported lower perceptions of Latino threat and punitiveness, relative to third-generation plus Latinos. Generational status was a significant moderator of perceived Latino threat on punitiveness. These effects vary by threat type. Respondents who identify as second-generation show that when perceiving greater than average economic threats, they become more supportive of border control policies. Policy implications include future voting preferences and the potential political shift of further generations of Latinos, and it’s impacts of support for harsh border control policies
Accessibility to Public Spaces: Intersections Between the Courts and the Houseless Community
No full textIn an attempt to answer the question of what role the judiciary played in affecting access to public spaces from the 1960\u27s to 2024, this thesis identifies an accumulation of patterns relating to the courts\u27 role in accessibility of public parks and their amenities over this time period. The data supplied for this question is drawn from scholars focusing on judicial decisions and political theory relating to public spaces, including those mentioned above. The result of this study will include a close examination of the role the judiciary holds as a cornerstone institution in not only our democracy, but in shaping future accessibility to public amenities. By establishing modern tests of constitutionality used by the courts and applied to the government, I argue the courts play an exceptionally important role, albeit quieter than the legislative or executive branches in access to public spaces. Particularly when looking at cases examining public spaces and the First, Fourth, Eighth and Fourteenth Amendments, the primary objective of this research is to analyze these court rulings to further understand the impact of these decisions. This thesis ultimately identifies how the courts have been active in deciding on the limits of public space accessibility for the houseless community
Geography of Non-Daytime Work and Employer-Centered Transit Accessibility
No full textNon-daytime shift workers--including those on evening, night, rotating, and split shifts--face unique transportation challenges. Those who rely on public transit often contend with complicated commutes and longer wait times on public transit systems that have traditionally catered to the 9-to-5 workforce. Meanwhile, the non-daytime workforce is disproportionately composed of marginalized groups, including low-income workers, racial and ethnic minorities, and individuals with fewer education credentials. For many lower-income workers, car ownership does not present a viable alternative, as cost-of-ownership consumes a significant portion of their income. This makes access to nighttime public transit a critical equity concern. However, most transit accessibility studies focus on daytime peak-hour services and are not industry-specific, with limited focus on measuring or increasing transit accessibility for non-daytime shift workers. Using transit and employment data from the Portland, Oregon region, this study proposes a method for first, tracking transit accessibility across a 24-hour period and, second, identifying which employment areas with limited nighttime service have the greatest potential to reach lower-income job seekers. The 24-hour analysis found that while daytime accessibility for equity populations saw system-wide improvements following the pandemic, the results for nighttime accessibility were mixed
2025 Commencement College of Urban and Public Affairs Ceremony Video
No full textVideo presentation of the PSU College of Urban and Public Affairs Commencement ceremony, held June 13, 2025, at the Viking Pavilion at Portland State University.https://pdxscholar.library.pdx.edu/commencement_2020s/1012/thumbnail.jp
An Evaluation of Therapeutic Harm Reduction and Psilocybin-Assisted Therapy Within Oregon\u27s Measure 109
No full textDespite psilocybin still being a Schedule I substance in the Federal Controlled Substance Act (OHA, 2022), Oregon voters passed Measure 109 in 2020, now codified into law as ORS457A, which allowed for the opening of psilocybin clinics for eligible clients. The passing of Measure 109 allowed for an adult-use model to be created, which is different from a therapeutic-use model. Advocates and Measure 109 framers employed the terms harm reduction and mental health support in order to secure the passing of Measure 109, but there is no specific definition of therapeutic harm reduction within M109 and ORS475A. To receive psilocybin services in Oregon, clients must be treated by a facilitator within an Oregon Psilocybin Services’-licensed clinic. This study uses semi-structured interviews and a short survey with 15 individuals who currently work in a legal psilocybin services setting to understand the perceptions and personal definitions of therapeutic harm reduction, and how those perceptions and definitions influence the specific therapeutic harm reduction techniques in their practice. The aim of this research is to provide understanding and a general definition of what therapeutic harm reduction is and what it entails from those who work as facilitators