Digital Commons Network^™

Strengthening Power Systems For Net Zero: A Review Of The Role Of Synchronous Condensers And Emerging Challenges, Hamid Soleimani, Daryoush Habibi, Mehrdad Ghahramani, Asma Aziz

Research outputs 2022 to 2026

System strength is both supplied and demanded in a power system during normal operations and in the presence of disturbances. This is characterised by stable voltage and frequency, supporting renewable generation such as wind and solar. Because the retirement of synchronous generators reduces system strength supply, and the connection of new inverter-based resource (IBR) generators increases demand, there is an urgent need for new sources of system strength. This paper provides an overview of the challenges brought about by grid modernisation. It highlights tangible solutions provided by synchronous condensers (SCs) to bolster grid strength, stability, and reliability while accommodating the …

Trust Dynamics In Sharing Economy Services During A Crisis: A Comparison Between Airbnb And Uber, Alireza Amrollahi, Tyge F. Kummer, Mehdi Rajaeian, Arghavan Hadinejad

Research outputs 2022 to 2026

This study investigates trust dynamics in sharing economy services during the COVID-19 crisis, comparing Airbnb and Uber as prominent representatives of accommodation and transportation services in tourism. Guided by two research questions, the study first explores the antecedents and mechanisms of trust creation on these platforms and then examines how the global pandemic affected trust in these services. The findings reveal that structural assurance, privacy protection, and social influence (only for Uber) are key antecedents of trust. Trust, in turn, significantly influences perceived usefulness and the intention to use both platforms. The results also show that perceived risk, heightened by …

Perceived Barriers And Enablers To Utilising The Australian National Disability Insurance Scheme For Adults With An Intellectual Disability And Their Families: A Scoping Review, Alice Zubrinich, Gideon De Jong, Nasim Salehi, Richard Lakeman

Research outputs 2022 to 2026

Background: The introduction of the National Disability Insurance Scheme (NDIS) in Australia in 2013 promised significant improvements in the lives of adults with intellectual disabilities. Although the scheme enables support, there are challenges associated with establishing eligibility and administering funds. This scoping review explored perceived barriers and enablers to effectively utilising the NDIS for adults with intellectual disabilities and their families. Method: A scoping review of the empirical literature on the NDIS and intellectual disabilities included nine studies in this review. These papers were subjected to thematic analysis and the findings were presented as a narrative synthesis. Results: The key …

Forms Of Fiscal Governance In The Euro Area – What Role For The Delegation Approach?, Ioannis Litsios, M Ctania, Mark Baimbridge

Plymouth Business School

Despite the common Euro Area (EA) requirements, we find notable differences in the quality of fiscal governance among the 19 member states. Moreover, characteristics of the delegation approach, which have been largely ignored in the EA fiscal governance framework, remain important in various member states. Using a two-way fixed effects panel data model for the EA countries during 2006–2018, we find that the delegation approach can be effective to improve the fiscal position. On the other hand, the imposition of centrally mandated common rules-based reforms has not taken into account the national political, social and institutional setting, and this may …

Who Profits From Trading Options?, Jianfeng Hu, Antonia Kirilova, Gilbert Seongkyu Park, Doojin Ryu

Research Collection Lee Kong Chian School Of Business

We use account-level transaction data to examine trading styles and profitability in a leading derivatives market. Approximately 66% of active retail investors predominantly hold simple, one-sided positions in only one class of options, whereas institutional investors are more likely to use complex strategies. Hypothesizing that the complexity of trading styles reflects investors' skills, we examine the effect of options trading styles on investment performance. We find that retail investors using simple strategies lose to the rest of the market. For both retail and institutional investors, selling volatility is the most successful strategy. We conclude that these style effects are persistent …

Hiv Estimation Using Population-Based Surveys With Non-Response: A Partial Identification Approach, Oyelola A. Adegboye, Tomoki Fujii, Denis H. Y. Leung, Siyu Li

Research Collection School Of Economics

HIV estimation using data from the demographic and health surveys (DHS) is limited by the presence of non-response and test refusals. Conventional adjustments such as imputation require the data to be missing at random. Methods that use instrumental variables allow the possibility that prevalence is different between the respondents and non-respondents, but their performance depends critically on the validity of the instrument. Using Manski's partial identification approach, we form instrumental variable bounds for HIV prevalence from a pool of candidate instruments. Our method does not require all candidate instruments to be valid. We use a simulation study to evaluate and …

Rank-Guaranteed Auctions, Wei He, Jiangtao Li, Weijie Zhong

Research Collection School Of Economics

We propose a combinatorial ascending auction that is “approximately” optimal, requiring minimal rationality to achieve this level of optimality, and is robust to strategic and distributional uncertainties. Specifically, the auction is rankguaranteed, meaning that for any menu M and any valuation profile, the ex-post revenue is guaranteed to be at least as high as the highest revenue achievable from feasible allocations, taking the (|M| + 1)th-highest valuation for each bundle as the price. Our analysis highlights a crucial aspect of combinatorial auction design, namely, the design of menus. We provide simple and sufficient menus in various settings.

Reading The Candlesticks: An Ok Estimator For Volatility, Jia Li, Dishen Wang, Qiushi Zhang

Research Collection School Of Economics

We propose an Optimal candlesticK (OK) estimator for the spot volatility using high-frequency candlestick observations. Under a standard infill asymptotic setting, we show that the OK estimator is asymptotically unbiased and has minimal asymptotic variance within a class of linear estimators. Its estimation error can be coupled by a Brownian functional, which permits valid inference. Our theoretical and numerical results suggest that the proposed candlestick-based estimator is much more accurate than the conventional spot volatility estimator based on high-frequency returns. An empirical illustration documents the intraday volatility dynamics of various assets during the Fed chairman's recent congressional testimony.

Development Of The Roadway Pothole Management Program, Dingxin Cheng

Mineta Transportation Institute

Addressing the issue of potholes is a primary concern for maintaining urban infrastructure. The research team has developed a prototype pothole management program. The program includes a mobile application and two machine learning models. The mobile app enables users to upload images of potholes, report relevant information, and provide driving directions to the pothole location. With the help of this application, the user can seamlessly capture images of the potholes, record pertinent information, and submit the data for necessary action. The mobile application is an essential tool in the Pothole Management Program (PMP), as it enhances the program's efficiency, effectiveness, …

Mapping Of Pavement Conditions Using Smartphone/Tablet Lidar Case Study: Sensor Performance Comparison, Calvin Beavers, Chad Day, Austin Krietemeyer, Scott M. Peterson, Yushin Ahn, Xiaojun Li

Mineta Transportation Institute

Poor road conditions affect millions of drivers, and assessing the condition of paved surfaces is a critical step towards repairing them. This project explores the feasibility of using the Apple iPad Pro LiDAR sensor as a cost-effective tool for assessing the damage and condition of paved surfaces. Our research aims to provide accurate and precise measurements using readily available consumer devices and compare the results to state-of-the-art equipment. This investigation involved visual inspection, identification, and classification of pavement distresses, followed by a comparison of the iPad and iPhone LiDAR data with a survey-grade terrestrial laser scanner. The project revealed several …

An Examination Of The Lived Experiences Of Black Women In Senior Leadership Roles At Cccu Member Institutions, Tuccoa Polk

Electronic Theses and Dissertations

This narrative inquiry qualitative research study explored the lived experiences of Black women in senior leadership roles at Council for Christian Colleges & Universities (CCCU) member institutions. Using Black feminist thought as the theoretical framework, this research study centered on the voices of 10 current or recently retired Black female senior-level leaders at CCCU campuses. The research study focused on one central research question and three subquestions that examined the challenges and barriers experienced by the participants, the role of mentorship in their leadership journey, and the impact of the participants’ Christian faith in their career trajectory to senior leadership …

Parental View On Hpv Vaccination, Rebecca Elaine Rhodes

Electronic Theses and Dissertations

The human papillomavirus (HPV) is a sexually transmitted infection widely seen in the United States. Millions of Americans are affected by it each year, especially those in their late teens and early 20s. Although most infections will resolve on their own, 1 in 10 will lead to health problems such as cancer. The HPV vaccine can prevent over 90% of associated precancers and cancers. However, uptake of the HPV vaccine and its completion among adolescents are significantly lower than other recommended adolescent immunizations, falling short of the Healthy People 2030 goal of 80% coverage. Understanding parental attitudes, beliefs, and perceptions …

Diversity Management And Organizational Resilience Among Midsized Cccu Institutions In Christian Higher Education, Kristopher M. Sutton

Electronic Theses and Dissertations

This exploratory qualitative cross-case analysis was developed to investigate how diversity management strategies were implemented and whether they coexist with organizational resilience capabilities at three U.S. private, midsized Christian-affiliated institutions of higher education associated with the Council for Christian Colleges & Universities. The researcher collected data from a senior-level chief diversity officer at each institution to determine how their diversity strategy was managed and whether a mature diversity program was concurrently present with organizational resilience capabilities. Data were collected using two primary instruments: the Diversity Management Competencies Questionnaire and semistructured interviews focused on organizational resilience. The collected data were supplemented …

Revised Draft Final Quarterly Operations And Maintenance Report Butte Treatment Lagoon System – Fourth Quarter 2022, Pioneer Technical Services, Inc.

Silver Bow Creek/Butte Area Superfund Site

No abstract provided.

Ductape: A Steady-State, Axisymmetric Ducted Fan Analysis Code Designed For Gradient-Based Optimization, Judd Mehr, Andrew Ning

Faculty Publications

Electric ducted fans have become an intriguing option for the propulsion systems of clean, quiet advanced air mobility technologies due to their potential benefits in both aerodynamic efficiency and reduced noise profiles compared to open rotor systems. Exploration of conceptual electric ducted fan design in the context of novel, and often complex, applications may be greatly aided by the use of optimization techniques. Specifically, gradient-based optimization lends itself to the exploration of large, complex, multi-disciplinary systems due to its inherent scalability. Despite ducted fans/propellers having been relatively well studied for the last century, modern, gradient-based, optimization-ready analysis tools for ducted …

Hierarchical Damage Correlations For Old Photo Restoration, Weiwei Cai, Xuemiao Xu, Jiajia Xu, Huaidong Zhang, Haoxin Yang, Kun Zhang, Shengfeng He

Research Collection School Of Computing and Information Systems

Restoring old photographs can preserve cherished memories. Previous methods handled diverse damages within the same network structure, which proved impractical. In addition, these methods cannot exploit correlations among artifacts, especially in scratches versus patch-misses issues. Hence, a tailored network is particularly crucial. In light of this, we propose a unified framework consisting of two key components: ScratchNet and PatchNet. In detail, ScratchNet employs the parallel Multi-scale Partial Convolution Module to effectively repair scratches, learning from multi-scale local receptive fields. In contrast, the patch-misses necessitate the network to emphasize global information. To this end, we incorporate a transformer-based encoder and decoder …

A Comparison Of Structure, Bonding And Non-Covalent Interactions Of Aryl Halide And Diarylhalonium Halogen-Bond Donors, Nicole Javaly, Theresa M. Mccormick, David R. Stuart

Chemistry Faculty Publications and Presentations

Halogen bonding permeates many areas of chemistry. A wide range of halogen-bond donors including neutral, cationic, monovalent, and hypervalent have been developed and studied. In this work we used density functional theory (DFT), natural bond orbital (NBO) theory, and quantum theory of atoms in molecules (QTAIM) to analyze aryl halogen-bond donors that are neutral, cationic, monovalent and hypervalent and in each series we include the halogens Cl, Br, I, and At. Within this diverse set of halogen-bond donors, we have found trends that relate halogen bond length with the van der Waals radii of the halogen and the non-covalent or …

Childhood Maltreatment And Amygdala-Mediated Anxiety And Posttraumatic Stress Following Adult Trauma, Farah Harb, Michael T. Liuzzi, Ashley A. Huggins, E. Kate Webb, Jacklynn M. Fitzgerald, Jessica L. Krukowski, Terri A. Deroon-Cassini, Christine L. Larson

Psychology Faculty Research and Publications

Background

Childhood abuse (physical, emotional, and sexual) is associated with aberrant connectivity of the amygdala, a key threat-processing region. Heightened amygdala activity also predicts adult anxiety and posttraumatic stress disorder (PTSD) symptoms, as do experiences of childhood abuse. The current study explored whether amygdala resting-state functional connectivity may explain the relationship between childhood abuse and anxiety and PTSD symptoms following trauma exposure in adults.

Methods

Two weeks posttrauma, adult trauma survivors (n = 152, mean age [SD] = 32.61 [10.35] years; women = 57.2%) completed the Childhood Trauma Questionnaire and underwent resting-state functional magnetic resonance imaging. PTSD and anxiety …

Determinants Of Youth Entrepreneurship In Kosovo, Dren Hima

Theses

This research aims to analyze the determinants of the probability of youth in Kosovo becoming nascent entrepreneurs. Kosovo, a young nation with a youth demographic and post-conflict socio-economic challenges, presents a unique context for studying entrepreneurship. The study focuses on the impact of both demographic and perceptual characteristics of the youth on their entrepreneurial orientation. The empirical analysis combines secondary data with primary data collected through an online survey targeting the youth of Kosovo, aged 18-29. It assesses the impact of various factors, including gender, educational background, household income, entrepreneurial experience, and perceptual variables like opportunity perception, fear of failure, …

A Spectroscopic Search For Recoiling Supermassive Black Holes In Nearby Active Galaxies, Emily Temple

Theses

It is hypothesized that following a galaxy merger the two central supermassive black holes (SMBH) become a binary system, eventually coalescing due to emission of gravitational waves. This coalescence results in a single black hole, with an accretion disk shining with high luminosity that photoionizes the surrounding gas. Therefore, the newly merged SMBH is visible as an active galactic nucleus (AGN). However, the gravitational waves are emitted anisotropically by the binary as it inspirals, resulting in a recoil kick. This ejects the newly merged SMBH from the AGN’s center of the galaxy. The SMBH oscillates around the galaxy’s center of …

Elementary Teachers' Self-Efficacy And Its Role In Stem Implementation, Caroline Buechel, Michael K. Daugherty, Vinson Carter, Emine Sahin Topalcengiz

Curriculum and Instruction Faculty Publications and Presentations

To equip students with 21st-century skills, teachers must have both deep STEM content knowledge and the confidence to implement and teach appropriate STEM content. Many elementary teachers have inadequate STEM background knowledge, low confidence, and STEM self-efficacy for implementing STEM in the classroom; as a result, teachers' classroom practices are affected. The study examined how elementary teachers perceive their ability to implement STEM in the classroom. The STEM Efficacy Survey was sent to a randomized pool of 100 elementary educators, and 18 of them agreed to participate in the study. This instrument was designed to elicit responses related to the …

On The Correlation Between Pre-Processing Workflow And Dimensional Accuracy Of 3d Printed Parts In High-Precision Material Jetting, Karin Chen, Ahmed Elkaseer, Steffen Scholz, Veit Hagenmeyer

Mechanical Engineering

Material Jetting (MJ) is distinguished in the additive manufacturing field for its ability to create accurate multi-material functional objects with features in the range of few micrometers. Analyzing the impact of each step in MJ from virtual design to 3D printed object on the process response is essential for optimizing the technology’s capabilities. The current state-of-the-art reveals a gap in MJ regarding the fundamental understanding of the correlation between the pre-processing workflow and the geometrical and dimensional accuracy. This study aims to bridge this gap by examining factors such as utilization of different CAD software with diverse working principles, part-based …

Relationship Commitment Regulation: Influencing A Partner's Commitment To Achieve One's Commitment Goals, Laura V. Machia, Kenneth Tan, Christopher R. Agnew

Research Collection School of Social Sciences

We introduce a model of relationship commitment regulation, which describes how romantic partners might use empirically-validated antecedents of commitment level strategically to influence a partner's commitment toward their relationship based on certain commitment goals they have for the relationship. People are generally aware of and relatively accurate with respect to knowing their partner's level of commitment and also have preferences regarding their desired level. We summarize key antecedents of commitment level (i.e., satisfaction level, alternative quality, investment size, future plans, and subjective norms) and then describe how each can be manipulated via relationship maintenance activities to move a partner's commitment …

Tumor-Immune Signatures Of Treatment Resistance To Brentuximab Vedotin With Ipilimumab And/Or Nivolumab In Hodgkin Lymphoma, Edgar Gonzalez-Kozlova, Hsin-Hui Huang, Opeyemi A Jagede, Kevin Tuballes, Diane M Del Valle, Geoffrey Kelly, Manishkumar Patel, Hui Xie, Jocelyn Harris, Kimberly Argueta, Kai Nie, Vanessa Barcessat, Radim Moravec, Jennifer Altreuter, Dzifa Y Duose, Brad S Kahl, Stephen M Ansell, Joyce Yu, Ethan Cerami, James R Lindsay, Ignacio I Wistuba, Seunghee Kim-Schulze, Catherine S Diefenbach, Sacha Gnjatic

Faculty, Staff and Student Publications

To investigate the cellular and molecular mechanisms associated with targeting CD30-expressing Hodgkin lymphoma (HL) and immune checkpoint modulation induced by combination therapies of CTLA4 and PD1, we leveraged Phase 1/2 multicenter open-label trial NCT01896999 that enrolled patients with refractory or relapsed HL (R/R HL). Using peripheral blood, we assessed soluble proteins, cell composition, T-cell clonality, and tumor antigen-specific antibodies in 54 patients enrolled in the phase 1 component of the trial. NCT01896999 reported high (>75%) overall objective response rates with brentuximab vedotin (BV) in combination with ipilimumab (I) and/or nivolumab (N) in patients with R/R HL. We observed a …

An Exploratory Study On E-Learning Software Utilization Among Professional Instructional Designers In Virginia, Mark Richard Parsons

STEMPS Theses & Dissertations

This master's thesis aims to explore the diverse landscape of e-learning software employed by professional instructional designers in Virginia to develop educational content. The study investigated the learning management systems and rapid authoring software, their utilization, the challenges and benefits associated with their usage, and future trends. By gaining insights into the preferences and practices of instructional designers, this research contributes to a deeper understanding of the dynamic field of e-learning software in the context of Virginia's educational landscape.

States And Multi-Hazard Early Warning Systems, Faith N. Masibili

Graduate Program in International Studies Theses & Dissertations

The lack of early warning systems for half of the countries worldwide and poor investments in regulatory frameworks to link early warnings to emergency plans exacerbates the exposure of populations at risk of natural hazards in livable urban environments. This study hypothesizes that the level of democracy, trade openness, economic prosperity, per capita public aid, hazard exposure, lack of coping and adaptive capacities, classification as least developed countries (LDC), landlocked developing countries (LLDC), and small island developing States (SIDS), population in urban areas, cellular mobile, state fragility index, and regional vulnerability impact the efficiency of a country’s early warning system. …

A Review Of Secondary Technology Education Teacher Needs In Virginia, M. Kathleen Ferguson

Educational Leadership & Workforce Development Theses & Dissertations

Technology education teachers can have varied pre-service training experiences, thus their needs for classroom support may vary greatly. Perkins V requires evidence-based research to justify the use of funding for professional development. This researcher sought to support Virginia’s secondary technology education teachers, professional organizations, and the Virginia Department of Education’s Technology Education Specialist by providing research to determine professional development needs. This three-phase qualitative study used a survey, documents review, and focus groups to triangulate data to provide information about the research questions. The research questions focused on teachers’ educational background, technology program goals, and issues specific to secondary technology …

Development Of A Conceptual Framework For Complex System Governance (Csg) Performance Measurement, James Hartwell Rutherford

Engineering Management & Systems Engineering Theses & Dissertations

Within the Complex System Governance (CSG) paradigm, system performance is regulated by nine metasystem governance functions, which provide control, communication, coordination, and integration. However, CSG has lacked a fully developed model or language to richly articulate system performance at a conceptual level. The purpose of this research was to develop a systems theory-based conceptual framework to measure the performance of CSG metasystem governance using an inductive research design.

Although ‘good performance’ may seem like an obvious idea, the current literature on performance measurement across many disciplines and contexts contains vastly inconsistent uses of the word ‘performance.’ Both researchers and practitioners …

Study Of Atypical Alarmone Synthesis In Clostridioides Difficile, Declan Nathaniel Butler

Chemistry & Biochemistry Theses & Dissertations

Clostridioides difficile is a Gram-positive anaerobic bacterium that causes infections in humans that costs healthcare systems billions per year. C. difficile infection has high rates of recurrence due to multiple antibiotic resistance. When bacteria are in stressful environments, they produce hyperphosphorylated guanosine ribonucleotide signaling molecules called alarmones. The accumulation of alarmones activates the stringent response (SR), in which bacterial cells induce transcription of stress survival genes to delay growth and replication. The C. difficile SR is regulated by enzymatic activity of a bifunctional synthetase/hydrolase, RelA/SpoT homolog (RSH), and a monofunctional small alarmone synthetase (RelQ). Additionally, the SR is potentially regulated …

Alternative Applications Of Composite Materials To Reduce Radar Cross Section, Mark Patterson

Mechanical & Aerospace Engineering Theses & Dissertations

The use of carbon nanoparticles and graphene in composite materials has created a foundational shift in enhancing performance across mechanical, thermal, and electrical properties. Such applications are vital in the aerospace industry. However, there has not been such a focus on the material use for reducing radar cross section (RCS). Historically, RCS is minimized by designing sharp geometric shapes to deflect or dissipate the incoming electromagnetic waves away from the receiving antenna. However, these designs are not always optimized for aerodynamics. The goal of this research is to understand the application of composite materials and specifically carbon nanotubes (CNTs) to …