21794 research outputs found
Sort by
Power Amplifier Designs For 5g V2x Wireless Communications And Sdr Transmitter Development
No full textABSTRACTPOWER AMPLIFIER DESIGNS FOR 5G V2X WIRELESS COMMUNICATIONS AND SDR TRANSMITTER DEVELOPMENT by SAEEDEH MAKHSUCI 2024 Advisor: Dr. Mohammed Ismail Co-advisor: Dr. Mihai Sanduleanu Major: Electrical Engineering Degree: Doctor of Philosophy
This research aims to develop Power Amplifier (PA) for 5G wireless communication. Anticipated demand for improved wireless communication services is expected to drive advancements and expansion in the 5G Network. The growing number of users, a desire for faster data rates, and enhanced connectivity have prompted markets to offer more efficient communication methods at a cost-effective approach. Our research not only focuses on the development of high-efficiency PAs but also explores the integration of inverse class D PA into Software-Defined Radio (SDR) systems. The PA serves as a fundamental element in a transmitter design which is the most power-consume component in the systems. As technology progresses, efficient management and improvement of PA performance become crucial for achieving optimal functionality and overall system efficiency in the transmitter architectures. The fast growth of 5G technology has triggered the demand for power amplifiers with high efficiency, making it easier to transmit large data volumes over long distances while lowering power consumption. Modern wireless systems mostly must support high data rates and bandwidth efficiency modulations that have high peak-to-average power ratios (PAPRs). One solution to this challenge is the Doherty Power Amplifier (DPA), a type of amplifier that allows for higher power efficiency while maintaining high output power levels. We introduced and compared two transformerless Series Doherty Power Amplifier (SDPA) architectures designed for 5.9 GHz frequency in 5G V2X communication using CMOS technology. The SDPAs utilize a balun as a replacement for the transformer and feature reduced area and cost compared to conventional parallel DPAs. Another solution to achieve a highly efficient Power Amplifier is by employing a switching PA. However, when employing a switching PA, it is essential to consider that the optimal modulation for it is one that transfers information through phase rather than amplitude. Hence, our focus involves the Inverse Class-D Power Amplifier and the transmitter of Software Defined Radios (SDR). In the design of switching PAs, a crucial consideration is to minimize the overlap between voltage and current. The core concept behind the Inverse Class-D Power Amplifier involves utilizing a delay to reduce the overlap between current and voltage. This power amplifier is being developed using advanced 22nm Fully Depleted Silicon On Insulator, or FD-SOI technology at a frequency of 28 GHz. Generally, there are two different types PAs, switching PAs and linear PAs. Our Doherty PAs are designed to achieve good gain and efficiency. Finally, SDR transmitter with Digital Outphasing Exponential Modulation is introduced. This transmitter uses an inverse Class D power amplifier (PA) implemented in 22nm FD-SOI technology
Air Quality And Human Health Effects Of Global Air Pollution: Model Development And Applications
No full textRegional and global air pollution contributes to poor air quality and adversely affects human health. However, chemical transport models still lack schemes in representing appropriate emissions to better simulate atmospheric chemistry and air quality, such as snowpack. In addition, the linkage between global sector-based anthropogenic emissions and human health effects associated with long-term exposure to ambient air pollutants, such as BTEX (Benzene, Toluene, Ethylbenzene, Xylene), PM2.5 (particles with an aerodynamic diameter ≤ 2.5 μm) and ozone (O3), are not well documented. Our work firstly implemented a scheme of source parameterization of snowpack-induced nitrogen oxides emissions in GEOS-Chem, which ultimately improved the tropospheric O3 simulating performance of the model by 1.57% and explained the discrepancies of tropospheric O3 distribution in polar regions. Our work focuses on the GEOS-Chem and CAM6-Chem simulated pollution impacts on BTEX, PM2.5 and O3 air quality and human health in terms of adverse birth outcomes like preterm births and premature deaths due to non-communicable diseases (NCDs) like stroke, chronic obstructive pulmonary disease (COPD), lung cancer, ischemic heart disease (IHD), and lower respiratory infections (LRIs). Our country-level analysis found that, global annual average BTEX exposure was up to 30 μg/m3 in 2015 that causes 2.01 million preterm births each year with large impacts in India, China, Pakistan, Indonesia, Bangladesh, United States and so on. Lastly, we investigated the long-term impacts of solid biofuel burning on PM2.5 and O3 air quality, as well as non-communicable diseases (NCDs) during 2000-2019. We found that solid biofuel emission supplied up to 23.6 μg/m3 PM2.5 and 13.7 ppbv O3 in 2010 and caused 1.11-1.43 million premature deaths due to NCDs annually during 2000-2019. Large air quality and human health impacts of solid biofuel burning were observed in China, India and Rest of Asia due to their large dependencies on solid biofuel for cooking and heating. This dissertation entails original works those are critically important to understand the air quality and human health impacts of natural and anthropogenic emissions
Neurodiversity In Selection: Examining Personality Testing In Selection For Autistic Individuals
No full textDespite robust evidence that personality tests are capable of identifying employees who are well suited for a job (Wilmot & Ones, 2021) there are populations of people who hold negative perceptions of personality testing, particularly as they apply to hiring neurodivergent individuals (Brown, 2021; Claypool, 2021). Additionally, various calls to action suggest a need to investigate neurodivergence in organizations, starting with barriers to obtaining employment (LeFevre-Levy et al., 2023). In light of this, the purpose of this study focused on one tool often used as a selection method, personality assessments. Focusing on autistic individuals, this study aimed to understand applicant reactions to personality assessments across autistic and non-autistic and whether there were differences in psychometric properties (i.e., measurement bias, predictive bias) of personality assessments across groups when used in an applicant context. Findings suggest that autistic individuals react less favorably to the use of personality assessments, and the effect is stronger when the personality assessment is not contextualized to a work environment. Further, non-autistic and autistic individuals scored significantly different on personality measures when contextualized to the work environment
Learning Without Being Taught: Evaluating Relational Framing Abilities In Young Adults
No full textABSTRACTLEARNING WITHOUT BEING TAUGHT: EVALUATING RELATIONAL FRAMING ABILITIES IN YOUNG ADULTS By BRADLEY J. DIXON November 2024 Advisor: Dr. John L. Woodard Major: Psychology (Clinical) Degree: Master of Arts Background. Relational Frame Theory (RFT) is an explicit behavioral theory of language development and functioning that has been applied to children and individuals with neurodevelopmental disorders (e.g., Autism Spectrum Disorder) to facilitate language development. Few studies have applied RFT principles to healthy adult populations, and RFT’s utility as a neuropsychological instrument remains mostly unexplored. The purpose of this study was to determine how training conditions impact learning arbitrary and non-arbitrary relationships in the fundamental relational frame of opposition. Methods. 50 young adults were tested on measures of crystallized intelligence, auditory working memory, associative verbal memory, and processing speed, as well as a novel opposition relations task developed according to RFT principles. During the opposition task, participants were taught two relations and asked to derive four other relations based on these trained relationships. 25 participants received congruent training where both relationships where trained as “opposites,” while 25 participants received incongruent training, training where one relationship was trained as “opposite” and the second relationship was trained as “equivalent.” Accuracy rates and response times were obtained when identifying all trained and derived relations. Results. Overall, Bayesian independent samples t-tests found moderate evidence of no differences in accuracy when identifying higher-order derived arbitrary and non-arbitrary relations between the two training groups. There was also very strong evidence that participants in the incongruent training condition took longer to identify higher-order non-arbitrary relations, with inconclusive evidence of any response time differences when identifying higher-order arbitrary relations between training groups. Additionally, there was evidence of strong positive associations between accuracy in identifying non-arbitrary relations with auditory working memory and a strong positive association between accuracy in identifying arbitrary relations with associative memory. Conclusions. These findings suggest that manipulating how stimulus relations are presented does not impact young adults’ ability to derive relationships accurately in the RFT paradigm, but it does appear to impact response time for non-arbitrary relationships. This study\u27s novel application of relational framing principles also showed promising relationships with existing associative and working memory measures
printed For The Benefit : British Women\u27s Benevolent Publications In The Long Eighteenth Century
No full textThis dissertation investigates publications that were printed or published by British women to generate income for charitable causes such as jails, hospitals, and distressed families in the long eighteenth century. I introduce the concept of the “benevolent publication” to describe these understudied publications, which are often, but with important exceptions, published provincially in small print runs. Specifically, this project is interested in material benefit, that is, instances where the profits—all or part—generated from the sale of benevolent publications are diverted out of the print trade and to the charitable object. Although the women authors and editors of these publications include those who are relatively unknown, I argue that they were professionals possessed of the skills and strategies necessary for publishing these texts.
To account for the authorial labor that exceeds the composition of these texts, I introduce the term “author-facilitated publication” to describe the broad variety of ways benevolent authors and editors were involved in the publication of their texts, including the negotiations with agents of the publishing process, the marketing and sale of these texts, and moving their profits to charities. I also recover the lasting role these publications play in literary and cultural history.
This project sits at the intersection of book history and literary history and uses feminist bibliographical methods to reinvestigate the material texts of benevolent publications to tell new stories about the roles these texts played, presenting this evidence in spreadsheets and tables, gathered through extensive archival research. This dissertation demonstrates that benevolent publications congeal as a recognizable genre within the eighteenth century with their own discourse in the literary reviews and cultural strictures regarding benevolence. This project shows through several examples that an anonymous text’s benevolent intent can offer opportunities for authorial attribution, encouraging us to revisit long held assumptions. More broadly, this dissertation uses the “hustle” of publishing benevolent publications to expand our understanding of authorial involvement in the publication of texts of all kinds during the eighteenth century
Exploring Teacher Pathway Programs: The Importance of High School Students’ Perspectives
Get PDFThis thesis explores and investigates the effectiveness of teacher pathway programs for high school students interested in education. The aim is to find and discuss the importance of teacher pathway programs and how they benefit the participants involved. This paper intertwines my analysis of the extant scholarly literature and my use of qualitative research methods during my immersion in two summer programs. Through participant observations and a survey, I gained insights into the participants’ perspectives that provided me with raw, unbiased views and opinions on the teacher pathway program. Student participants’ perspectives include the experiences they faced during the program, the benefits they received, and reflections on how the program impacted them as aspiring educators. The major themes from my research on participants reveal how the programs succeeded in benefiting the participants in multiple ways, including becoming prepared for college life/experiences, gaining a boost of confidence towards teaching, learning teaching skills/tools, and opening doors of opportunities. Additionally, participant observation from Next Gen Teachers Programs reveals how the teaching experience, participant reflections, and final presentations shaped participants’ perspectives on a teaching career and becoming a teacher. Within the analyzed questionnaires, participants expressed how Next Gen Teachers Programs positively impacted their view on teaching and provided benefits. Overall, this thesis displays how these programs are influential in growing passion and confidence in teaching and giving opportunities for high school students to see and feel what a teaching career entails
Examining The Impact Of Yoga And Mindfulness On Perceived Caregiver Stress And Burden
No full textPURPOSE: In the United States, there are approximately 34 million informal caregivers; defined as individuals who provide unpaid help to older adults (Lavela & Ather, 2010). Among this population, there is a growing health concern focusing on the potential physical and psychological risks linked to caregiving. Therefore, the purpose of this study was to investigate how a yoga and mindfulness intervention may influence changes in caregivers’ perceptions of stress and burden as well as their resting heart rate (HR) and blood pressure (BP). METHODS: Eight caregivers participated in an eight-week yoga and mindfulness intervention, with 60- minute sessions featuring gentle warm-up sequences, yoga asanas (poses), focused breathing, guided meditation, body scans, journaling, and themed peer discussions. A qualitative approach was used to capture data including pre-and post-intervention semi-structured interviews and surveys (Perceived Stress Scale and Zarit Burden Interview), as well as pre-and post-test RHR and BP readings. Thematic analysis was used to identify patterns across the semi-structured interviews. Surveys, RHR, and BP measures were assessed for percent changes using the formula (V2−V1) / |V1|×100. RESULTS: Pre to post-test quantitative measures revealed decreases in perceptions of stress (37.57%) and caregiver burden (22.40%) along with a decrease in RHR (3.45%). However, there were increases in BP, systolic (0.89%), and diastolic (4.14%). The post-intervention qualitative themes included recognizing the need for self-care, peer support, accountability & motivation, participants’ declaration of physical & mental benefits of the intervention, study modalities deemed impactful, and the application of yoga and mindfulness techniques off the mat and into the world. CONCLUSION: Taken collectively, these results indicate that yoga and mindfulness activities may help caregivers of older adults manage their perceptions of stress and burden. With additional research, this may be a plausible option as an affordable and accessible wellness modality to help mitigate the potential long-term, negative health outcomes associated with the caring role
Integrating Degradation Sensor Data to Operations and Pricing Problems in Energy Systems
No full textMaintenance scheduling and management play a crucial role in the operation andmaintenance (O&M) policies of power systems, significantly affecting their total expenditures [2, 3]. For example, 20%-25% of the total levelized cost per kWh of wind turbines can be linked to maintenance operations [4]. The harsh and continuously changing operating environments lead to degradation of generation assets within these systems, which require maintenance interventions to maintain or restore their normal conditions [5]. Uncontrolled degradation can lead to frequent outages, unexpected failures, and lower system reliability. In complex and interconnected power systems, asset outages and failures can further disrupt production and service processes, cause plant shutdowns, and, in extreme cases, lead to disasters [6]. Therefore, it is essential to balance the focus on reducing maintenance costs with ensuring system reliability [7]. The growing size and operational uncertainties of power systems add to the challenges of establishing proper O&M regimes. The variability in renewable assets’ production capacity, electricity demand, and market prices significantly contribute to the impact of maintenance downtime on the overall performance of these systems. To minimize the impact of maintenance downtime on the system, maintenance decisions should adapt to changes in units’ health conditions and operational requirements. To tackle these challenges, various maintenance management policies have been proposed. Preventive maintenance policies are designed to reduce failure instances, especially for critical components, by conducting maintenance actions at predetermined intervals. Time-based (periodic) maintenance (TBM) is the most common preventive maintenance strategy in the energy industry, in which units are maintained based on a calendar time or machine run-time [8, 9]. Maintenance intervals are obtained through manufacturer recommendations, engineering expertise, and field observations [10,11]. Maintenance intervals are generally established by collecting failure time data of assets of similar types and using them to develop population-based failure distributions. These population-based failure distributions are then used to predict the time of failure for specific assets within the power system
“a Tedious And Comfortless Uniformity Of Time”: Narratives Of Aging In The Long Eighteenth Century
No full textThis project explores representations of aging women in eighteenth-century courtship novels to interrogate the ways that these novels so seemingly focused on youth are actually grounded in and constructed through representations of old age. More specifically, it looks at representations of aging women in the middle period of their lives, to argue that depictions of aging in novels by Frances Burney, Maria Edgeworth, Jane Austen, and Sarah Scott play a central role in the development of the courtship narrative in the eighteenth century and beyond. This dissertation argues that aging women serve as figures who actively undermine or disrupt the prescribed course of life for young women (courtship, marriage, motherhood) that these novels seemingly seek to inscribe as the ideal future. The older characters in each of these novels range in their presentation from stereotypically grotesque to emblems of virtue and goodness; however, they all repeatedly disrupt and defer the marriage plot, take over the narrative space, draw continued attention to the past and memory, or court premature aging, and in doing so can manipulate or circumvent heteronormative marriage. Through an exploration of these novels, I argue for a close link between representations of aging and of temporality. Ultimately, I argue, that in their continual disruption of the normative ‘course of life’ these representations offer glimpses of alternative timelines, timelines not focused on linear progress toward the future ending in marriage, but rather ones that make space for alternative kinship structures centered on female friendship
Coordination Chemistry Of Low-Valent Lanthanide Ions
No full textThe stabilization of 5d orbitals in complexes of divalent lanthanide (LnII) ions relative to their trivalent lanthanide (LnIII) counterparts enables tuning of the optical and electrochemical properties of LnII ions by varying ligand field strength around LnII. This ability to control the properties of LnII ions has led to an increasing number of studies aimed at understanding the coordination chemistry of LnII for target applications such as lighting, photocatalysis, the design of medical imaging probes, and the design of sensors. However, many reported studies on the impact of ligand field on the structural, optical, and electrochemical properties of LnII ions have primarily focused on probing the impact of varying the type of donor atoms. Less attention has been devoted to understanding the impact of varying ligand denticity and steric hindrance on the structural, optical, and electrochemical properties of LnII ions. Thus, my PhD research is focused on addressing this gap in knowledge regarding the impact of ligand denticity and steric hindrance on the structural, optical, and electrochemical properties of LnII ions. Variation in ligand denticity and counterion identity generated complexes of LnII ions (Ln = Eu or Sm) with a wide range of coordination numbers (6–10) and geometries (octahedron, trigonal prism, capped trigonal prism, capped octahedron, triangular dodecahedron, hexagonal bipyramid, cube, capped cube, muffin, sphenocorona, staggered dodecahedron, and bicapped square antiprism). This variation in ligand field strength through changes in ligand denticity, steric factors, or donor atom identity enabled a broad range turnability of the emission colors of EuII from UV to yellow and trailing into orange (300–635 nm). In addition, changes in ligand field strength led to variation in the absorption properties of complexes of SmII from blue to near-IR of the electromagnetic spectrum. Furthermore, the electrochemical properties of two cryptates of SmII that differ only in the strength of Lewis basicity of amine donors revealed that increasing the strength of Lewis basicity of ligand donor atoms in a cryptate of SmII increases its reducing power. These findings describing the impact of ligand field on the structural, optical, and electrochemical provide critical insights for tailoring the design of new complexes of LnII ions with properties suitable to specific applications