Open Research Oklahoma (Oklahoma State Univ.)
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Empowering mothering in education: A study of West African graduate student mothers at an institution of higher education in the United States
No full textThis study looks at the experiences of West African graduate student mothers pursuing graduate degrees in the U.S. It delves into how they deal with motherhood, their cultural identities, and the challenges of graduate school. It is this intersectionality of the identity of West African graduate student mothers that makes their educational experiences and paths complex (Crenshaw, 1991), and the empowerment that enables these student mothers to develop agency and resilience in a challenging environment (Longwe, 1991). I conducted in-depth interviews with seven (7) West African graduate student mothers from Ghana, Nigeria, and Cameroon pursuing graduate studies at a PWI in the United States. My findings reveal that these women encounter significant challenges, including cultural adjustment difficulties, financial constraints, limited institutional support, and struggles balancing academic workloads with childcare responsibilities (George Mwangi et al., 2019; Irungu, 2013). These challenges often lead to stress and anxiety, impacting both their academic performance and personal well-being. Despite these challenges, the participants demonstrated resilience and determination by developing coping mechanisms such as time management strategies, seeking support from peers and family, and utilizing available campus resources as they turned their challenges into educational and professional opportunities (Lobnibe, 2013). These graduate student mothers often create supportive networks that blend traditional and modern childcare methods (Lynch, 2008). To empower West African graduate student mothers and improve their educational experiences in the United States, the study recognizes the need for higher education institutions to implement focused support systems, such as affordable childcare services, flexible academic scheduling, and culturally sensitive support. These results agree with recent research suggesting similar challenges encountered by international and African mother graduate students studying in U. S. universities (Evivie, 2009; Haitova, 2023; Lobnibe, 2013)
Impact of virtual reality on stuttering and heart rate in virtual and real-life settings: A mixed methods study
No full textVirtual reality (VR) is a promising adjunct to traditional therapies for people who stutter (Al Nafjin, 2021; Brock, 2023; Brundage, 2008; Cecil et al., 2024; Tentu et al., 2024). In spite of these results, we are uncertain of the impact of using VR to promote carryover of therapeutic gains into real world settings. Three research questions were explored for the purpose of this study. They are 1) Is there a statistically significant difference in the percentage of stuttered syllables between pre-test measures within a Virtual Reality simulation, post-test measures following take-home therapy within the Virtual Reality simulation, and the real-life parallel post-intervention? 2) Is there a statistically significant difference in anxiety, as measured by heart rate, between pre-test measures within a Virtual Reality simulation, post-test measures following take-home therapy within the Virtual Reality simulation, and the real-life parallel post-intervention? 3) What are participants’ feelings and experiences of stuttering in the Virtual Reality simulations and their real-life parallels? Percentage of stuttering decreased from pre-test measures in VR to post-test in VR and from pre-test in VR to real life settings, The percentage of stuttering decreased from pre-test to post-test measures in VR and from pre-test in VR to the real-life parallels. However, there was an increase in stuttering frequency between post-VR and real-life parallels. These differences did not reach statistical significance, but there was a statistically significant difference for heart rate between pre-test and real-life measures. Also, heart rate increased from pre-test to real-life. A qualitative thematic analysis was conducted on semi-structured interviews regarding the participants experience regarding VR, which were completed after the real-life parallel post-intervention, resulting in four major themes and ten sub-themes. Clinical and research implications show promising trends for VR as an adjunct to traditional stuttering therapy
Assessing productivity of secondary mathematics’ discussions and activities
No full textStudents’ discussions about and engagement with mathematics largely shape their conceptualizations and dispositions towards learning and doing mathematics. It is crucial for educators, particularly at the secondary level, to facilitate discussions and activities that not only engage students, but support their development of productive reasoning. The purpose of this thesis is to create a theoretical framework “assessing productivity” of discussions and activities based on related literature and empirical research. This framework will be used to analyze various aspects of students’ participation in classroom instruction, such as the students’ mathematical thinking and the prior knowledge required to meaningfully engage in the lesson. The goal of the research is to discern how to promote students’ understanding at a deeper level than memorizing facts and becoming fluent with procedures. I applied this framework to analyze recorded data from my instruction in a secondary classroom as a pre-service secondary mathematics educator. After teaching my lessons, I reflected on the effectiveness of the tasks and discussions I facilitated in the classroom in regards to productive struggle. I then analyzed the discussions and activities according to a three tier model reflecting cognitive demand and progress in doing mathematics. This analytical framework for productivity of mathematics’ discussions and tasks is applicable at a large scale level when evaluating the effectiveness of instructional practices and/or curricular resources for secondary mathematics
Final design report: Bio-inspired guitarist
No full textThe goal of the Bio-memetic Inspired Guitar project is the development of a wearable prosthetic that restores the abilities with limb injuries and limb differences to play music on a guitar. The objective this semester was to design a proof-of-concept device that achieved the base functions of a single finger. These base functions include flexion at three points of articulation and adduction/abduction of the entire finger. The team developed a robust apparatus that utilized a Raspberry Pi, multiple motors, dedicated peripheral controls, and internally developed software to achieve these goals. The final prototype was assessed for endurance, actuating the same repeating motion for 8 consecutive hours. The base point of flexion at the knuckle was not able to be driven as intended but further development make this item functional. The device provides a jumping-off point for groups in future semesters to complete the design and create a fully operational prosthetic
Power side-channel attack detection and secure analog-to-digital conversion circuits
No full textCryptographic devices play a crucial role in the transmission of secure information.The inclusion of data capturing in day-to-day life comes with the need for the safe implementation of these algorithms. This thesis starts with the detection of malicious power side-channel attacks (PSCA) on cryptographic devices. Secure implementations are vulnerable to attacks leveraging statistical analysis techniques, which can reveal the secret key. A dedicated detection circuit enables enhanced security without increasing complexity in the sensitive circuit. The switched capacitor (SC) circuit actively detects power side-channel attacks within the chip and identifies current sensing resistor insertions by a malicious foundry on the PCB. This work opens a new avenue for mixed-signal-based implementation in existing chip design flows without the need for excessive add-on hardware. This work enabled the newer designs capable of sensing much lower insertion resistance (Rs).
The increase of analog-to-digital (ADC) converters embedded in the Internet of Things (IoT) also demands secure data conversion. Convolutional Neural Network (CNN) models enable the security characterization of an unsecured ADC. The traces from the unsecured ADC are used as features to train the CNN model. The prediction of bits from the models exploits the vulnerability of an unsecured design. The security parameters of the unsecured ADC set the baseline for comparison. This work presents a secure ADC designed to resist power side-channel attacks. This work presents an 8-bit Flash-SAR ADC designed to improve resistance against power side-channel attacks, with minimal overhead in power, performance, and area. The findings of this research enable new directions for research in secure hybrid or Two-Step ADC implementations. The secure ADC is designed and simulated using a TSMC 65nm CMOS technology.
The contribution sets a benchmark for detection circuits in a mixed-signal environment. It utilizes CNN to characterize secure ADCs and compare the security of different designs. The work introduces the use of two-step/hybrid ADCs for secure implementation in sensitive information handling devices
Effect of rocket pre-detonator operating conditions and mixing methods on detonation reliability
No full textThis thesis presents an examination of various rocket pre-detonator operating parameters to determine the effect of each on detonation reliability and to develop an operating envelope for a variety of applications. Pre-detonators are used to initiate detonations with rotating detonation rocket engines, which have the potential to outperform conventional liquid rocket engines in specific impulse due to an increase in pressure during combustion. A pre-detonator could also be used as an effective ignition system for other aerospace applications such as liquid rockets or scramjets. The pre-detonator must successfully generate a detonation at different operating conditions for good reliability, and it must be compact for aerospace applications. For a pre-detonator, the variable parameters are initial pressure, equivalence ratio, and ignition delay. For this study, a notional pre-detonator was built based on existing designs to function using gaseous hydrogen and oxygen. In order to define the baseline operating map for the pre-detonator, the operating parameters were varied to find the edges of the working envelope. Near the edges of operability, an uncertainty study was conducted. This led to a robust multi-dimensional map of the combined operating parameters that lead to reliable detonations. Different geometric mixing features were studied to determine their influence on detonation reliability at the different operating conditions. It was found that, while the mixing devices did not affect the detonation reliability of the pre-detonator, injection timing scheme and equivalence ratio had a significant impact as mixing of the combustion gases was found to be a significant factor in detonation success rate. The most successful condition for detonation was found to use 10 bar or higher feed pressure, and equivalence ratio near 0.5, and a zero ms ignition delay. The pre-detonator was generally insensitive to ignition delays of less than 500 ms and fill fractions greater than 30%. Detonations were achieved at lower feed pressures, but reliability failed after departing from equivalence ratio of 0.5. By pulsing the fuel or oxidizer valve, it was shown that the reliable equivalence ratios were increased from a range of 0.45 to 0.55 to a range of 0.15 to 0.675. These results will inform the design of future pre-detonators to supply reliable detonations for any high-energy ignition need
Elective Bible courses in public schools: A qualitative case study of successful implementation and sustainability
No full textThis qualitative case study explores how an elective Bible course has been implemented in a rural public-school district in the Midwest and has been able to continuously sustain it for at least 10 years. It looks at what the perceptions of the teacher and administrators are regarding how to successfully implement and sustain this course. Using the theoretical lens of liberal democratic pluralism, this case study explored how this course supported the tenets of student autonomy and mutuality. The findings of this study suggest that an overarching paradigm of trust exists at the case study site in the form of community cooperation. This trust appeared to be the result of the school district’s leadership stability, leadership oversight, teacher selection, and the utility of the course
Effects of eastern redcedar (Juniperus virginiana) encroachment on soil organic carbon and soil microbial communities in grasslands along a precipitation gradient
No full textGrassland ecosystems represent an important global carbon sink and store approximately one third of the global terrestrial carbon stock belowground in soil organic matter. Woody plant encroachment is an imminent threat to grasslands worldwide and may represent a potentially significant redistribution of carbon between terrestrial pools. Juniperus virginiana, hereafter eastern redcedar, has proliferated into grasslands across the Southern Great Plains due to fire exclusion. Transition from grassland to eastern redcedar woodland increases aboveground carbon stock but impacts on belowground carbon dynamics remain uncertain. Soil organic carbon dynamics are strongly influenced by plant and soil microbial interactions, and eastern redcedar encroachment may disrupt important plant-microbial associations that facilitation soil carbon cycling in grasslands. To investigate the effects of eastern redcedar encroachment on SOC stock and related soil microbial communities, we sampled nine soils and roots at nine sites across Oklahoma’s east to west precipitation gradient. We expected that eastern redcedar soils would have greater SOC stocks compared to grassland soils. Soil cores were extracted from two depth increments, (0-10 cm) and (10-30 cm), respectively, to determine bulk density and SOC content. We also assessed relative abundances of soil microbial functional groups, including intra- and extraradical arbuscular mycorrhizal (AM) fungi, gram-positive and gram-negative bacteria, and saprophytic fungi associated with eastern redcedar and adjacent grasslands. SOC stocks were greater beneath eastern redcedar trees (19.2 Mg C ha-⁻¹ as compared to grasslands (15.9 Mg C ha⁻¹) in upper soil depths (0-10 cm) and there was no difference in lower soil depth. Intraradical AM fungal colonization levels were lower in eastern redcedar roots (24.2%) than in the roots of grassland species (30.6%) (p value < 0.001), yet AM fungal biomass was greater in eastern redcedar soils (7.34 nmol g⁻¹ soil) compared to grassland soils (4.33 nmol g⁻¹ soil) in upper soil depths (0-10 cm) (p-value = 0.009). Saprophytic fungal biomass, gram positive and negative bacterial biomass, and total microbial biomass were also greater beneath eastern redcedar than grasslands in upper soil depths
A “capsular” model for non-contact diffuse reflectance spectroscopy of two-layer medium by center-illuminated-area-detection
No full textThis study examines a forward model of total diffuse reflectance from a two-layer medium for non-contact dual-channel diffuse reflectance spectroscopy (DRS) using centerilluminated- area-detection (CIAD) [Piao et al, 2025, App. Opt.]. The model takes after a “capsular” approach initially demonstrated for radially resolved measurements from a solid organ of <1mm thick capsule when probed by contact DRS [Piao et al, 2018, J. Biomed. Opt.], which via radial integration is viable for DRS in CIAD of a two-layer medium. The integral operation of the model keeps the “capsular” essence to relax the diffuse reflectance measured from a two-layer medium to that from a mono-layer medium upon the vanishing of the interlayer contrast. The resulting analytical model has been tested against Monte Carlo simulations of two-layer geometries with a 1-3mm top layer, an inter-layer two-way scattering contrast changing 2 orders of magnitude, an inter-layer two-way absorption contrast varying 4 orders of magnitude, and the radius of CIAD up to 15mm for 1” cage-applications. This “capsular” forward model for CIAD-based total diffuse reflectance of two-layer medium has been applied to experimental non-contact DRS engaging a center-accepted and center-blocked dual-channel configuration of CIAD. Applications to two-layer media having a 1.6mm thick layer of soft tissue and differing in the substrate base medium among aqueous phantoms of varied scattering and absorption, solid phantoms differing in absorption, and bulk avian tissues demonstrated the forward utility of the “capsular” model for non-contact assessment of below-surface medium presenting spectral absorption contrast with respect to a thick superficial layer.Electrical and Computer Engineerin