Previous literature suggests that engineers are known for lacking communication skill and training, despite an illustrated need for it established by accredited engineering organizations. Limited research has been done to effectively include communication competencies in engineering education. The current study sought to identify what communication competencies research engineers need to function at a research and development center, and to develop recommendations for training for both university and workplace setting. This qualitative case study included semi-structured, in-depth interviews with 10 employees of the U.S. Army Corps of Engineer’s premier research center: Engineer Research Development Center (ERDC). The sample consisted of six research engineers and four other allied professionals. The analysis indicated that engineers valued the three main competencies of collaboration, audience adaptation, and interpersonal understanding. These are built upon foundational skills, including oral and visual communication skills, written skills, and active listening skills. Results also showed that engineers preferred an integrated approach to engineer communication training and identified university courses and workplace trainings as two different sources of communication learning. Findings were consistent with two theories of communication learning: communication across the curriculum (CXC) and communication in the disciplines (CID). Practical applications are offered for educators in communication and engineering fields, as well as career development professionals.

The primary purpose of this study is to evaluate the current state of affairs regarding regulatory compliance and passenger safety aboard commercial aircraft. Throughout the broad scope of the number of unique airline operations throughout the United States and the world, special consideration is given in order to ensure that passengers are both safe inflight and prepared for contingencies that can arise. The continued safety of passengers and crew members is the highest priority in every operational scope within the aviation industry. The process through which passenger awareness of safety is achieved, specifically during 14 CFR Part 121 and Part 135 commercial airline operations, is executed through the performance of live safety demonstrations by flight attendants, presentation of operator-developed videos, and the provision of printed safety cards to passengers who are encouraged (and in some cases legally required) to view them. Through the analysis of data derived from a newly distributed research study, current passenger attitudes towards safety and regulatory compliance onboard commercial aircraft will be measured and weaknesses identified. This research will leverage this data to identify and defend possible methods to improve the quality of airline passenger safety awareness and regulatory compliance procedures. Identified improvements involve inquiry into the relationships created between flight crewmembers and passengers, and also include potential modifications to procedural components such as emergency exit row briefings.

National Airspace Systems (NAS) are complex cyber-physical systems that require swift air traffic management (ATM) to ensure flight safety and efficiency. With the surging demand for air travel and the increasing intricacy of aviation systems, the need for advanced technologies to support air traffic management and air traffic control (ATC) service has become more crucial than ever. Data-driven models or artificial intelligence (AI) have been conceptually investigated by various parties and shown immense potential, especially when provided with a vast volume of real-world data. These data include traffic information, weather contours, operational reports, terrain information, flight procedures, and aviation regulations. Data-driven models learn from historical experiences and observations and provide expeditious recommendations and decision support for various operation tasks, directly contributing to the digital transformation in aviation. This dissertation reports several research studies covering different aspects of air traffic management and ATC service utilizing data-driven modeling, which are validated using real-world big data (flight tracks, flight events, convective weather, workload probes). These studies encompass a range of topics, including trajectory recommendations, weather studies, landing operations, and aviation human factors. Specifically, the topics explored are (i) trajectory recommendations under weather conditions, which examine the impact of convective weather on last on-file flight plans and provide calibrated trajectories based on convective weather; (ii) multi-aircraft trajectory predictions, which study the intention of multiple mid-air aircraft in the near-terminal airspace and provide trajectory predictions; (iii) flight scheduling operations, which involve probabilistic machine learning-enhanced optimization algorithms for robust and efficient aircraft landing sequencing; (iv) aviation human factors, which predict air traffic controller workload level from flight traffic data with conformalized graph neural network. The uncertainties associated with these studies are given special attention and addressed through Bayesian/probabilistic machine learning. Finally, discussions on high-level AI-enabled ATM research directions are provided, hoping to extend the proposed studies in the future. This dissertation demonstrates that data-driven modeling has great potential for aviation digital twins, revolutionizing the aviation decision-making process and enhancing the safety and efficiency of ATM. Moreover, these research directions are not merely add-ons to existing aviation practices but also contribute to the future of transportation, particularly in the development of autonomous systems.

The rapid growth of emerging technologies is placing enormous demand on the seamless access to the extensive amount of data, which drives an unprecedented need for substantially higher data-transfer rates. As 1.6 Terabit Ethernet (TbE) specifications are being developed, high speed interconnects along with advanced materials and processes play a crucial role in technology enabling. However, validation of interconnect performance becomes increasingly challenging at these higher speeds. High-speed interconnect behavior can be reliably predicted if interconnect models are successfully validated against measurements. In industry, it is still not common practice to perform validation at actual use conditions. Therefore, there is an urge for a restructured design methodology and metrology based on temperature and humidity, to set realistic specs for high speed interconnects and reduce probability of failure under variations. Uncertainty quantification and propagation for interconnect validation is critical to assess the correlation quality more objectively, as well as to determine the bottleneck to improve the accuracy, repeatability and reproducibility of all the measurements involved in validation. The purpose of this work is to create a methodology that is both academically rigorous and has a significant impact on industry. This methodology provides an accurate characterization of the electrical performance of interconnects under realistic use-conditions, accompanied by an uncertainty analysis to improve the assessment of correlation quality. Part of this work contributed to the Packaging Benchmark Suite developed by IEEE EPS technical committee on electrical design, modeling, and simulation.

This study introduces a new outdoor accelerated testing method called “Field Accelerated Stress Testing (FAST)” for photovoltaic (PV) modules performed at two different climatic sites in Arizona (hot-dry) and Florida (hot-humid). FAST is a combined accelerated test methodology that simultaneously accounts for all the field-specific stresses and accelerates only key stresses, such as temperature, to forecast the failure modes by 2- 7 times in advance depending on the activation energy of the degradation mechanism (i.e., 10th year reliability issues can potentially be predicted in the 2nd year itself for an acceleration factor of 5). In this outdoor combined accelerated stress study, the temperatures of test modules were increased (by 16-19℃ compared to control modules) using thermal insulations on the back of the modules. All other conditions (ambient temperature, humidity, natural sunlight, wind speed, wind direction, and tilt angle) were left constant for both test modules (with back thermal insulation) and control modules (without thermal insulation). In this study, a total of sixteen 4-cell modules with two different construction types (glass/glass [GG] and glass/backsheet [GB]) and two different encapsulant types (ethylene vinyl acetate [EVA] and polyolefin elastomer [POE]), were investigated at both sites with eight modules at each site (four insulated and four non-insulated modules at each site). All the modules were extensively characterized before installation in the field and after field exposure over two years. The methods used for characterizing the devices included I-V (current-voltage curves), EL (electroluminescence), UVF (ultraviolet fluorescence), and reflectance. The key findings of this study are: i) the GG modules tend to operate at a higher temperature (1-3℃) than the GB modules at both sites of Arizona and Florida (a lower lifetime is expected for GG modules compared to GB modules); ii) the GG modules tend to experience a higher level of encapsulant discoloration and grid finger degradation than the GB modules at both sites (a higher level of the degradation rate is expected in GG modules compared to GB modules); and, iii) the EVA-based modules tend to have a higher level of discoloration and finger degradation compared to the POE-based modules at both sites.

The design of energy absorbing structures is driven by application specific requirements like the amount of energy to be absorbed, maximum transmitted stress that is permissible, stroke length, and available enclosing space. Cellular structures like foams are commonly leveraged in nature for energy absorption and have also found use in engineering applications. With the possibility of manufacturing complex cellular shapes using additive manufacturing technologies, there is an opportunity to explore new topologies that improve energy absorption performance. This thesis aims to systematically understand the relationships between four key elements: (i) unit cell topology, (ii) material composition, (iii) relative density, and (iv) fields; and energy absorption behavior, and then leverage this understanding to develop, implement and validate a methodology to design the ideal cellular structure energy absorber. After a review of the literature in the domain of additively manufactured cellular materials for energy absorption, results from quasi-static compression of six cellular structures (hexagonal honeycomb, auxetic and Voronoi lattice, and diamond, Gyroid, and Schwarz-P) manufactured out of AlSi10Mg and Nylon-12. These cellular structures were compared to each other in the context of four design-relevant metrics to understand the influence of cell design on the deformation and failure behavior. Three new and revised metrics for energy absorption were proposed to enable more meaningful comparisons and subsequent design selection. Triply Periodic Minimal Surface (TPMS) structures were found to have the most promising overall performance and formed the basis for the numerical investigation of the effect of fields on the energy absorption performance of TPMS structures. A continuum shell-based methodology was developed to analyze the large deformation behavior of field-driven variable thickness TPMS structures and validated against experimental data. A range of analytical and stochastic fields were then evaluated that modified the TPMS structure, some of which were found to be effective in enhancing energy absorption behavior in the structures while retaining the same relative density. Combining findings from studies on the role of cell geometry, composition, relative density, and fields, this thesis concludes with the development of a design framework that can enable the formulation of cellular material energy absorbers with idealized behavior.

Leadership is an essential component of engineering career success, yet early-career engineers report a lack of leadership skills entering the workplace. Studies have suggested that mentoring opportunities have the potential to provide an alternative approach to learning and practicing leadership. What is not yet understood is to what extent and in what ways serving as a mentor develops leadership. This dissertation fills this knowledge gap by sequentially conducting qualitative and quantitative studies examining how serving as a research mentor influences engineering graduate students and postdoctoral scholars’ leadership understanding and competencies. Study participants were recruited from short-term research programs offered by National Science Foundation (NSF)-funded Engineering Research Centers (ERCs). A total of 17 former ERC mentors and 75 current ERC graduate students and postdoctoral scholars participated in the qualitative study and the quantitative study, respectively. The results suggest that serving as a research mentor can help to advance leadership understanding and competencies. The qualitative study discovered that former ERC mentors believed they gained new perspectives of leadership and developed their leadership competencies while serving as a mentor. This included a growth in awareness of importance to express empathy toward other people and ability to develop others and delivering project results. The quantitative study demonstrated that ERC mentors reported higher competencies in leading other people and delivering project results compared to their peers who had not served as mentors. ERC mentors still primarily connected leadership to leaders, despite the noted gains. This finding indicated the ERC mentors have not yet fully captured the true essence of leadership. The overall evidence suggests that serving as a mentor in a short-term program provided an effective and efficient opportunity for ERC graduate students and postdoctoral scholars to further their understanding of what it means to be a leader and improve their competencies of being a good leader. Such experiences left much to be desired in establishing a social, processual view on leadership.

Humans possess the ability to entrain their walking to external pulses occurring atperiods similar to their natural walking cadence. Expanding the basin of entrainment has become a promising option for gait rehabilitation for those affected by hemiparesis. Efforts to expand the basin have utilized either conventional fixed-speed treadmill setups, which require significant alteration to natural walking biomechanics; or overground walking tracks, which are largely impractical. In this study, overground walking was simulated using an actively self-pacing variable speed treadmill, and periodic hip flexion perturbations (≈ 12 Nm) were applied about a subject using a Soft Robotic Hip Exoskeleton. This study investigated the effectiveness of conducting gait entrainment rehabilitation with simulated overground walking to improve the success rate of entrainment at high frequency conditions. This study also investigated whether simulated overground walking can preserve natural biomechanics by examining stride length and normalized propulsive impulse at various conditions. Participants in this study were subjected to four perturbation frequencies, ranging from their naturally preferred gait frequency up to 30% faster. Each subject participated in two days of testing: one day subjects walked on a conventional fixed-speed treadmill, and another day on a variable speed treadmill. Results showed that subjects were more frequently able to entrain to the fastest perturbation frequency on the variable speed treadmill. Results also showed that natural biomechanics were preserved significantly better on the variable speed treadmill across all accelerated perturbation frequencies. This study showed that simulated overground walking can aid in extending the basin of entrainment while preserving natural biomechanics during gait entrainment, which is a promising development for gait rehabilitation. However, a comparative study on neurologically disordered individuals is necessary to quantify the clinical relevance of these findings.

The world faces significant environmental and social challenges due to high economic development, population growth, industrialization, rapid urbanization, and unsustainable consumption. Global communities are taking the necessary measures to confront these international challenges and applying sustainable development principles across all sectors. Construction is a critical driving instrument of economic activity, and to achieve sustainable development, it is vital to transform conventional construction into a more sustainable model. The research investigated sustainable construction perceptions in Kuwait, a rapidly growing country with a high volume of construction activities. Kuwait has ambitious plans to transition into a more sustainable economic development model, and the construction industry needs to align with these plans. This research aims to identify the characteristics of sustainable construction applications in the Kuwaiti construction market, such as awareness, current perceptions, drivers and barriers, and the construction regulations' impact. The research utilized a qualitative approach to answer research questions and deliver research objectives by conducting eleven Semi-structured interviews with experienced professionals in the Kuwaiti construction market to collect rich data that reflects insights and understandings of the Kuwaiti construction industry. The Thematic analysis of the data resulted in six themes and one sub-theme that presented reflections, insights, and perspectives on sustainable construction perceptions in the Kuwaiti construction market. The research findings reflected poor sustainable construction awareness and poor environmental and social application in the construction industry, the determinant role of construction regulations in promoting sustainable construction. and barriers and drivers to sustainable construction applications. The research concluded with answers to research questions, delivery of research objectives, and an explanation of sustainable construction perceptions in the Kuwaiti construction market.

For decades, engineering scholarship has presented data to address the underrepresentation of Black womxn in the engineering doctoral community. American Society of Engineering Education (ASEE)’s Engineering by the Numbers Report (2021) statistically showed that only 57 Black womxn out of 10,037 scholars received engineering doctorates in 2021. Engineering scholars have theorized about constructs ranging from whiteness to explain the system, to doctoral socialization to explain the culture, to retention explain the experiences. Yet, even with the plethora of scholarship, the problem of underrepresentation has remained consistent with limited action towards change from the faculty, the program, or the institution. Therefore, I aim to address this problem by cultivating emotional resonance toward action within the engineering community regarding engineering doctoral program underrepresentation for Black womxn. Using Arts-Based Research (ABR) and Black Feminist Thought (BFT), this dissertation illustrates the engineering PhD spirit-murdering experiences of Black womxn. Six Homegirls intellectually contributed to this study by sharing their time and experiences through artistic expressions and homegirl conversations. Through the lens of BFT’s matrix of domination, the composite blog shows that spirit-murdering for these Homegirls: 1) is a targeted act that is dehumanizing 2) occurs because of the aloof nature and capitalist ideals of the engineering academy, and 3) causes further conflict in negotiating identities as Black, woman, professional, researcher, and student. Leaning on BFT’s grounding as an Afrocentric methodological approach, the composite poem illustrates that these Homegirls: 1) have a common, understood epistemology because of their shared experiences of being Black and woman in their current, multi-layered social locations, 2) identify strongly with their positionality and values while describing their outsider-within status, and 3) experience spirit-murdering in an emotional, intellectual, and spiritual way that then results in physical manifestations. Rooted in BFT’s ethic of caring, the hip-hop mixtape’s progression describes homegirl’s spirit-renewal tactics as: 1) owning their professional identity, 2) dispelling projected biases, stereotypes, and aggressions, 3) calling out inequities in their interpersonal relationships and program culture, 4) learning to set boundaries to protect themselves, and 5) standing on their ways of knowing and being.