In applications spanning across aerospace, marine, automotive, energy, and space travel domains, composite materials have become ubiquitous because of their superior stiffness-to-weight ratios as well as corrosion and fatigue resistance. However, from a manufacturing perspective, these advanced materials have introduced new challenges that demand the development of new tools. Due to the complex anisotropic and nonlinear material properties, composite materials are more difficult to model than conventional materials such as metals and plastics. Furthermore, there exist ultra-high precision requirements in safety critical applications that are yet to be reliably met in production. Towards developing new tools addressing these challenges, this dissertation aims to (i) build high-fidelity numerical simulations of composite assembly processes, (ii) bridge these simulations to machine learning tools, and (iii) apply data-driven solutions to process control problems while identifying and overcoming their shortcomings. This is accomplished in case studies that model the fixturing, shape control, and fastening of composite fuselage components. Therein, simulation environments are created that interact with novel implementations of modified proximal policy optimization, based on a newly developed reinforcement learning algorithm. The resulting reinforcement learning agents are able to successfully address the underlying optimization problems that underpin the process and quality requirements. / Doctor of Philosophy / Within the manufacturing domain, there has been a concerted effort to transition towards Industry 4.0. To a large degree, this term refers Klaus Schwab's vision presented at the World Economic Forum in 2015, in which he outlined fundamental systemic changes that would incorporate ubiquitous computing, artificial intelligence (AI), big data, and the internet-of-things (IoT) into all aspects of productive activities within the economy. Schwab argues that rapid change will be driven by fusing these new technologies in existing and emerging applications. However, this process has only just begun and there still exist many challenges to realize the promise of Industry 4.0. One such challenge is to create computer models that are not only useful during early design stages of a product, but that are connected to its manufacturing processes, thereby guiding and informing decisions in real-time. This dissertation explores such scenarios in the context of composite structure assembly in aerospace manufacturing. It aims to link computer simulations that characterize the assembly of product components with their physical counterparts, and provides data-driven solutions to control problems that cannot typically be solved without tedious trial-and-error approaches or expert knowledge.

This thesis focuses on how cultural connections in classroom influences students value of learning, specifically, their value of reading. Several researchers and theorists have emphasized the importance of balancing cognitive and conative aspects of childrens reading development. However, what is lacking in these studies is a focus on Pacific Islander (PI) children. The purpose of this study was to examine value of reading for diverse students who may be struggling in classrooms designed for White, middle-class students. Findings provide educators and those working with diverse students a chance to consider how connecting cultural backgrounds for all students can help in classrooms. This study was framed from a larger study on equity in teaching academic language conducted by the supervising professor, Dr. Bryant Jensen. This research study used a mixed method approach: multiple regression analysis to predict gains in PI students reading values, and interviews with classroom teachers. Fourth through sixth grade Latino and PI students in 32 classrooms participating in the quantitative study, and three teachers were interviewed. Due to the short time frame, PI students value of reading did not increase on average. Themes also emerged during interviews with the classroom teachers. I conclude with a discussion, implications, and recommendations for future research studies and educators working with PI and other diverse students.

A key distinction between today's and tomorrow's wireless networks is the appetite for reliability to enable emerging mission-critical services such as ultra-reliable low-latency communication (URLLC) and hyper-reliable low-latency communication (HRLLC), the staple mission-critical services in IMT-2020 (5G) and IMT-2023 (6G), for which reliable and resilient communication is a must. However, achieving ultra-reliable communication is challenging because of these services' stringent reliability and latency requirements and the stochastic nature of wireless networks. A natural way of increasing reliability and reducing latency is to provision additional network resources to compensate for uncertainty in wireless networks caused by fading, interference, mobility, and time-varying network load, among others. Thus, an important step to enable mission-critical services is to identify and quantify what it takes to support ultra-reliable communication in mobile networks -- a process often referred to as dimensioning. This dissertation focuses on resource dimensioning, notably spectrum, for ultra-reliable wireless communication. This dissertation proposes a set of methods for spectrum dimensioning based on concepts from risk analysis, extreme value theory, and meta distributions. These methods reveal that each ``nine'' in reliability (e.g., five-nines in 99.999%) roughly translates into an order of magnitude increase in the required bandwidth. In ultra-reliability regimes, the required bandwidth can be in the order of tens of gigahertz, far beyond what is typically available in today's networks, making it challenging to provision resources for ultra-reliable communication. Accordingly, this dissertation also investigates alternative approaches to provide resources to enable ultra-reliable communication services in mobile networks. Particularly, this dissertation considers multi-operator network sharing and multi-connectivity as alternatives to make additional network resources available to enhance network reliability and proposes multi-operator connectivity sharing, which combines multi-operator network sharing with multi-connectivity. Our studies, based on simulations, real-world data analysis, and mathematical models, suggest that multi-operator connectivity sharing -- in which mobiles multi-connect to base stations of operators in a sharing arrangement -- can reduce the required bandwidth significantly because underlying operators tend to exhibit characteristics attractive to reliability, such as complementary coverage during periods of impaired connectivity, facilitating the support for ultra-reliable communication in future mobile networks. / Doctor of Philosophy / A key distinction between today's and tomorrow's wireless networks is the appetite for reliability to enable emerging mission-critical services in 5G and 6G, for which ultra-reliable communication is a must. However, achieving ultra-reliable communication is challenging because of these services' stringent reliability and latency requirements and the stochastic nature of wireless networks. Reliability often comes at the cost of additional network resources to compensate for uncertainty in wireless networks. Thus, an important step to enable ultra-reliable communication is to identify and quantify what it takes to support mission-critical services in mobile networks -- a process often denoted as dimensioning. This dissertation focuses on spectrum dimensioning and proposes a set of methods to identify suitable spectrum bands and required bandwidth for ultra-reliable communication. These methods reveal that the spectrum needs for ultra-reliable communication can be beyond what is typically available in today's networks, making it challenging to provide adequate resources to support ultra-reliable communication services in mobile networks. Alternatively, we propose multi-operator connectivity sharing: mobiles simultaneously connect to multiple base stations of different operators. Our studies suggest that multi-operator connectivity sharing can reduce the spectrum needs in ultra-reliability regimes significantly, being an attractive alternative to enable ultra-reliable communication in future mobile networks.

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Notwithstanding the negative influence of demotivation on student learning outcomes, prior research in EFL demotivation suffers from the lack of generally agreed-upon conceptual understanding, which hampers scale development. The present series of studies sought to explore the ideas of demotivation and describe the development of the Learner Perception of Demotivators Scale (LPDS) both conceptually and psychometrically. In Study 1 (N = 295), an exploratory factor analysis offered preliminary support for a factor structure comprising three dimensions: negative teacher behavior, loss of task value, and low expectancy for success. In Study 2 (N = 320), the proposed factor structure was further corroborated through confirmatory factor analysis, and its validity was documented by means of correlating with academic performance, self-efficacy, and mindset. A second-order factor model was tested to investigate whether a set of demotivating factors load on an overall construct that may be termed “Demotivator”. Whereas the model fit confirmed a wellitting second-order model with post hoc model adjustment, one low first-order loading (negative teacher behavior) does not seem to support “Demotivator” as a higher order construct comprising three subdimensions. Furthermore, the LPDS demonstrated evidence of configural, metric, scalar, and residual invariance across gender, suggesting the same underlying construct is measured across gender groups. Contrary to the findings in motivation research, loss of task value was a stronger predictor of performance than low expectancy for success. Further, in Study 3 (N =320), loss of task value distinguished extremely motivated EFL learners from ordinary ones, offering tentative evidence for the reason behind demotivation in EFL learning. The unique role of task value found in Study 2 and Study 3 gave insights into the hypothetical construct of “demotivation”. It was also examined in the context of East Asian culture. By establishing a nomological network (academic performance, self-efficacy, and mindset), the current study provided a lawful pattern of interrelationships that exists between the hypothetical construct (demotivation) and observable attributes (e.g., academic performance) and that guides researcher for future L2 studies. More implications and limitations for future studies are discussed.

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Fundamental engineering courses are important to the undergraduate engineering student experience but have been associated with challenging educational environments. Several factors influence the educational environment, although learning experiences are primarily the outcome of interactions between instructors and students. To initiate change, it is important to understand teaching and learning experiences in fundamental engineering courses from the perspectives of the key players in these environments: instructors and students. To accomplish the goal of understanding teaching and learning experiences, I conducted studies that examined instructors' and students' perspectives on their experiences and the educational environments, using qualitative research methodology. Through these studies, this dissertation: 1) examined instructors' beliefs and self-described behaviors, guided by motivation theory and focusing on the role of instructors as socializers in the learning process; 2) considered interacting fundamental engineering courses as a foundational curriculum within engineering curricula to describe the educational environment in these courses from instructors' perspectives; and 3) examined student perceptions of their learning experiences and the educational environments in fundamental engineering courses using responses to open-ended items in end-of-semester student evaluations of teaching surveys. Data indicate that participants strive to integrate strategies that promote effective learning despite challenges posed by course environments, although expected gains from these behaviors may not always be maximized. Students and instructors may benefit from a student-focused, collaborative and holistic course planning process that considers interacting fundamental courses as a foundational curriculum within engineering curricula, and that engages instructors as equal partners in the planning process. Student feedback may be infused into the course planning process by productively and meaningfully utilizing students' responses to end-of-semester student evaluations of teaching surveys. Overall, the results of this dissertation highlight the importance of institutional support, collaboration, and integrating student feedback in the quest for facilitating effective educational environments and positive learning experiences in engineering. / Doctor of Philosophy / Introductory engineering courses are important to engineering students’ college experience but have been associated challenging learning environments. Several factors influence the learning environment, although learning experiences are primarily the outcome of interactions between instructors and students. To initiate change, it is important to understand teaching and learning experiences in introductory engineering courses from the points of view of the key players in these environments: instructors and students. To accomplish the goal of understanding teaching and learning experiences, I conducted qualitative studies that examined instructors’ and students’ points of view on their experiences and the learning environments. Through these studies, this dissertation: 1) examined instructors’ beliefs and self-described behaviors, guided by motivation theory and focusing on the role of instructors as socializers in the learning process; 2) considered interacting introductory engineering courses as a foundational curriculum within engineering curricula to describe the learning environment in these courses from instructors’ points of view; and 3) examined student perceptions of their learning experiences and environments in introductory engineering courses using responses to open-ended items in end-of-semester student evaluations of teaching surveys. Results show that participants strive to integrate strategies that promote effective learning despite challenges posed by learning environments, although the expected benefits from these strategies may not always be realized. Students and instructors may benefit from a student-focused, collaborative and holistic course planning process that considers interacting introductory engineering courses as a foundational curriculum within engineering curricula, and that involves v instructors as equal partners in the planning process. Student feedback may be included in the course planning process by productively and meaningfully using students’ responses to end-of-semester student evaluations of teaching surveys. Overall, the results of this dissertation highlight the importance of institutional support, collaboration, and integrating student feedback in the quest for facilitating effective learning environments and positive learning experiences in engineering.

According to a report from McAfee, the global cost of cybercrime for 2020 was over one trillion dollars (Smith, Z. et al., 2020). Cybersecurity breaches and attacks have not only cost businesses and organizations millions of dollars but have also threatened national security and critical infrastructure. Examples include the Ransomware attack in May of 2021 on the largest fuel pipeline in the United States and the February 2021 remote access system breach of a Florida water treatment facility which raised sodium hydroxide to a lethal level. Improving cybersecurity requires a skilled workforce with relevant knowledge and skills. Academic degree programs, boot camps, and various certification programs provide education and training to assist this need. Cyber ranges are a more recent development to provide hands-on skill training. These ranges, often virtual, provide a safe and accessible environment to improve practical skills and experience through hands-on application. They provide a training environment to identify threats, apply countermeasures, and secure data from risks separately from the organization's actual network. More and more academic programs utilize cyber ranges due to the perceived benefit of integrating them into their cybersecurity-related programs. Academic cyber ranges offer virtualized environments that support cybersecurity educators' needs to provide students with a safe, separated, and engaging environment. The purpose of my research has two components: 1) to understand who the educators are using academic-facing cyber ranges and how they are using them to support their cybersecurity education efforts, and 2) to understand how cybersecurity educators and students are motivated by using them. Specifically, my research is comprised of three manuscripts: (1) a mixed-method exploratory study of who are the educators using cyber ranges for cybersecurity education and how they are using them to create significant cybersecurity learning experiences, (2) a mixed-method study exploring the motivation of educators using a cyber range for cybersecurity education, and (3) a mixed-method study exploring student motivation participating in cybersecurity CTF competitions. The three manuscripts contribute to understanding cyber ranges in cybersecurity education. The results from my research provided insight from the users of these cyber ranges, cybersecurity educators and students. Results from my first manuscript suggested that high school cybersecurity educators are the primary users. These educators have less formal cybersecurity education and experience compared to cybersecurity educators in higher education. The data also showed that cybersecurity educators primarily used cyber ranges for teaching and learning to meet learning goals and objectives. Results from my second manuscript suggested that educators were motivated mainly by the importance of using a cyber range for cybersecurity education and for the interest-enjoyment their students experience from cyber range usage. Educators found using the cyber range made their class more engaging and relevant to their students.These educators were also confident they could use a cyber range and learn how to use it. However, those without prior experience in cybersecurity or previous experience using a cyber range shared they needed instructor-facing resources, professional development opportunities, and time to learn. Results from my third manuscript suggested that students were motivated by the importance of participating in a cybersecurity CTF competition. Many reported that participating was useful for developing professional skills and readiness. Although CTF competitions were considered difficult and stressful, students did not consider the difficulty pejorative. Many shared that challenging CTFs contributed towards the enjoyment of participating, making them a rewarding and worthwhile experience. However, students also shared that academic and team support contributed towards their confidence in competing. In contrast, those who did not report confidence, stated they lacked a team strategy or support from their academic institution. Additionally, they did not know what to expect to prepare before the competition event. Overall, the results of this dissertation highlight the importance of prior preparation for educators and student CTF participants. For educators, this prior preparation includes curriculum supporting resources such as content mapping to learning objectives and professional development opportunities that do not assume any prior knowledge or experience. For students, prior preparation includes understanding what to expect and recommendations for academic and team support. / Doctor of Philosophy / The technology era has enabled a global connectedness to attend conferences and meetings via our laptop computers while working from home. The proliferation of smart devices has also provided a means to view and communicate with visitors who ring our smart doorbells while we are not home. This interconnected network, i.e., the Internet, has altered how we pay our bills, buy our groceries, and attend classes virtually. It has also enabled cyber attacks and breaches that have contributed to identity thefts, increasing financial costs, business collapses, job losses, and even threatened national security. A cybersecurity workforce has become increasingly vital to address the need for improving cybersecurity. Thus, there is a need for academic cybersecurity programs to prepare future professionals to fill this national workforce shortfall. Consequently, more and more organizations have integrated cyber ranges as the means to provide a simulated environment for applying and developing cybersecurity-related knowledge and skills. Similar to a driving range for a golfer to practice their golf swing or a shooting range for those in law enforcement to earn their firearms qualifications, a cyber range supports efforts to provide cybersecurity training with hands-on exercises and labs to practice skills in a safe, virtual environment. My research contributes to understanding who uses cyber ranges and how they are motivated to use them for cybersecurity education. The first purpose of my research was to understand the educators who were using cyber ranges and how they were using them for cybersecurity education. More specifically, I examined their usage for alignment with a learning taxonomy to verify the usage contributed to successful and significant student learning. This understanding contributed to my research's second purpose, which explored how educators were motivated using cyber ranges. The third purpose of my study explored student motivation using a cyber range. Due to varying cyber range resources and activities, my research focused on the cybersecurity competition activity, Capture the Flag (CTF). This study provided an understanding of how students who participated in a cybersecurity CTF competition were motivated. My research demonstrates that educators and students are interested in using cyber ranges and believe using them for cybersecurity education and professional readiness is important. However, both educators and students who lack prior knowledge or experience using a cyber range or participating in a CTF shared the concern of not knowing what they do not know. PD time and instructor-facing resources that do not assume any prior cybersecurity knowledge were recommended to support educators who did not have a background or experience in cybersecurity. Students shared that although not knowing was stressful and made participating difficult, the difficulty and stress were good attributes because if the CTF were easy, it wouldn't be worth their time and would be less rewarding. Students also reported that team strategies and academic support were motivational aspects of CTF participation. Overall, educators and students were motivated using cyber ranges for cybersecurity education, but professional development and preparation resources would contribute positively to their usage.