Open Research Oklahoma (Oklahoma State Univ.)
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Mixed-methodology investigation into the societal and economic benefits of systematically integrating beyond visual line of sight uncrewed aircraft systems operations into complex airspaces
No full textThe aviation industry is perhaps the single-most complex socioeconomic sector in existence today. Similarly, the United States domestic airspace is perhaps the most complex in the world. These complexities were compounded on September 28, 2005 when the Federal Aviation Administration (FAA) issued the first airworthiness certificate for a civil uncrewed aerial vehicle. The increase in multiplicity continued with the introduction of FAA Part 107 in June of 2016 and the issuance of the first Beyond Visual Line of Sight (BVLOS) waiver on April 1, 2019. The utilization of Uncrewed Aircraft Systems (UAS) has catalyzed the expedited evolution of economic sectors and forever altered the innate structure of the FAA. As a result of regulatory ambiguity and political intricacies, the uncrewed industry has become overly and unnecessarily complex. The goal of this study was to explore ways of furthering societal and economic growth through systematically integrating BVLOS UAS operations into complex environments, such as smart cities. It is proposed that the current waiver-based system be utilized as a stepping stone, rather than an end-all-be-all solution; regulatory simplification will occur as a result of transitioning to a rules-based system. This mixed-methods study exploited instruments to include in-depth interviews of subject matter experts (SME) and a comprehensive survey to acquire a thorough understanding of how uncrewed aircraft can continue to be utilized in a manner capable of catalyzing future domestic social and economic growth. A purposeful sample of SMEs was utilized for the interview segment of this study. A mixed-methods survey was distributed to 385 individuals via multistage quota sampling wherein one city (Philadelphia, PA) was randomly selected from a list of the 19 U.S. cities that appear on the IESE Cities in Motion Index using the Stat Trek random number generator. A representative quota sample (n=385) of male and female individuals aged 20-60 was selected from Philadelphia in order to glean a more comprehensive understanding of how BVLOS UAS operations are viewed in the eyes of industry experts and the individuals who will be living in cities where the proposed Internet of Drones (IoD) BVLOS infrastructure is to be implemented. The results of the interviews and surveys were collated and analyzed through a gap analysis to achieve the ultimate goal of understanding the benefits of systematic UAS integration. This research study aimed to be crucial in furthering understanding of how uncrewed aircraft can push the boundaries of the aviation sector and related industries while maintaining the ultimate level of safety to which the aviation industry is accustomed
State of COVID-19 in Oklahoma: Patterns, socio-interrelations, and accessibility
No full textCOVID-19, which hit the world in December 2019, has been a great cause of concern, requiring intense research to curb the virus and create focused policies and management. Therefore, the focus of this research is to provide invaluable insights and add to existing knowledge on the COVID-19 virus by using GIS based models to analyze the spatial and spatiotemporal patterns of COVID-19 in Oklahoma. Due to the nature of the virus, it is important to continually assess the geographic distribution of cases and deaths as well as factors that contribute to the patterns. The study therefore uses GIS based methods such as the Getis-Ord Gi* statistic, space time cubes, and time series clustering to identify hotspots of COVID-19 cases and deaths in Oklahoma. The results showed that hotspots of COVID-19 cases were found around Oklahoma City where hotspots of Blacks and Hispanics are located. In contrast, for COVID-19 deaths, significant hotspots pattern was found in rural areas mainly where significant hotspots of American Indians are located. In addition, a significant uptrend of COVID-19 cases was found in a few zip codes, and a significant decrease in COVID-19 deaths was found in most zip codes located in the state. Lastly, areas experiencing similar increase and decrease trends in both COVID-19 cases and deaths were identified. Future work is needed to identify the binding factors that may be causing similar upward and downward trend in the virus
Bayesian approach to infer changes in disease transmission
No full textCompartmental models are popular in epidemic modeling because they help to understand and predict the spread of infectious diseases. Existing compartmental models for modeling
epidemics such as COVID-19 include SIR, SEIR, and numerous variations of each of these.
However, few of these models incorporate mobility data to determine changes in disease
transmission rates. In this dissertation, I will build a statistical model to infer whether there
is a change in the transmission rate of a compartmental model, given that there is a change
in human mobility. I propose a model which allows different transmission rates for different
time periods so that a model comparison approach can be used to test if a change-point in
disease transmission should be present in the model. In order to achieve that, parameter
estimation using partial epidemic data is done using a Bayesian approach. In particular, a
Bayesian state-space model is specified and inference is made through a particle filter and
the Metropolis Hastings method. Model comparison for testing the change is done using
the deviance information criterion (DIC). Replicability of the algorithm is assessed using a
simulation study where I calculated the average bias and average mean squared error for the
parameter estimation. I also performed a simulation study to assess the DIC approach. The
simulation study revealed that the algorithm was able to accurately estimate the parameters.
Further, whenever there is a large enough change in the transmission rate from one period
to the next, then the DIC would select the model that incorporated a change-point in the
disease transmission
Emergency management in a post-COVID-19 world: a futurological study of hospital preparedness in South-Central Pennsylvania
No full textFocusing events—such as the terrorist attacks of September 11, 2001, Hurricanes Katrina and Sandy, and the COVID-19 pandemic—have profoundly shaped both individual and societal perceptions of emergencies and disasters. These are “sudden, relatively rare events that can be reasonably defined as harmful or revealing the possibility of future harms, inflicting or suggesting concentrated harms on a definable geographical area or community of interest, and known to policymakers and the public virtually simultaneously” (Rob A. DeLeo, 2021). Such events have significantly influenced the evolution of emergency management as a discipline. This study employs a qualitative Straussian grounded theory approach to examine the central research question: What are the essential elements of an effective and efficient hospital Emergency Management Program that reduces morbidity and mortality within the context of COVID-19? To address this question, the research draws on insights from 30 semi-structured interviews with hospital emergency managers, and other key COVID-19 response stakeholders, in South Central Pennsylvania. Data analysis revealed five major thematic categories: (1) Emergency Management Structures and Strategy; (2) People and Professional Development; (3) Resource Constraints and Infrastructure; (4) Culture, Values, and Ethics; and (5) Innovation and Future Outlook. Together, these themes form the theoretical foundation of the study, which is conveyed through ten key recommendations. This research contributes a novel and substantive perspective to the field of hospital emergency management by illuminating the emergence of a new paradigm for the hospital emergency manager—one characterized by expanded roles, dynamic responsibilities, and an integrated systems approach. This study demonstrates that when emergency managers and hospital leaders employ data-driven improvement processes, such as After Action Reviews (AARs), leverage Artificial Intelligence (AI) and advanced technologies, and foster broad-based stakeholder collaboration, their Emergency Management Programs achieve enhanced resilience, greater organizational trust, and a sustainable culture of preparedness embedded in routine operations
Nucleophilic cobalt photocatalysis: Vitamin B₁₂-photocatalyzed cyclopropanation reactions
No full textRecently, the cyclopropane moiety has become crucial in drug design. This ubiquitous moiety in natural products and other biologically active compounds has been shown to enhance drug properties and is extensively studied for various pharmaceutical and therapeutic applications. Over the years, the need for synthetic methods to make this strained three-carbon ring structure remains, due to challenges such as limited substrate scope and selectivity issues that affect common approaches, including the Simmons-Smith and Corey-Chaykovsky reactions. Additionally, the demand for more effective, efficient, and environmentally friendly approaches to organic synthesis emphasizes the need for alternative methods. Photocatalyzed radical-polar crossover approaches to making cyclopropanes have been developed; however, they rely on expensive and/or reactive methylene sources, such as methyl diazo salts and diiodomethane. This work leverages nucleophilic cobalt photocatalysis, employing dichloromethane as a cheap, readily available methylene source to install the cyclopropyl ring onto alkenes. Biocompatible, environmentally friendly cyanocobalamin (vitamin B₁₂) has shown highly nucleophilic properties in its reduced form (the Coᴵ oxidation state) and can perform Sₙ2-type substitution reactions with carbon electrophiles. The resulting Coᴵᴵᴵ–C bond is relatively weak (BDE ≈ 14-42 kcal/mol) and can be homolyzed under photochemical or thermal conditions to generate useful reactive intermediates. In this work, we present a photo-mediated approach to the synthesis of cyclopropanes, enabling the generation of chloromethyl radicals from dichloromethane using vitamin B₁₂ photocatalysis to install the cyclopropyl group onto a variety of electron-deficient alkenes. We have advanced this approach further by using haloforms as a source of halomethyl radical intermediates under vitamin B₁₂ photocatalysis to prepare monohalogenated cyclopropanes from electron-rich alkenes, which can serve as excellent building blocks for diverse molecular scaffolds. This mild approach to preparing monohalogenated cyclopropanes also provides access to the synthetically less accessible cis-1,2-disubstituted cyclopropane. Finally, we have successfully demonstrated the synthetic utility of our approach with various pharmaceutically relevant transformations. Currently, efforts to synthesize monofluorocyclopropanes using our vitamin B₁₂-photocatalyzed approach are underway. Consequently, this vitamin B₁₂-photocatalytic approach to cyclopropane synthesis could be useful for the preparation of a variety of cyclopropanes, offering a direct and efficient route to these valuable moieties
Human motion enhancement through deep learning
No full textHuman motion analysis is a rapidly developing field of computer vision with a wide variety of applications including biomedical study, athletic observation, computer interfaces, entertainment media development, and video classification. The goal of human motion analysis is to model the human body in a concise form, generally as a skeletal model. I propose a new deep learning method for enhancement of human motion data through the use of non-linear Kalman filtering inside of the latent space of a convolutional autoencoder trained on high quality optical Mocap human motion data. This method takes advantage of a learned human motion manifold as well as preserving the original motion kinematics through the use of Kalman Filtered data. In addition, I propose a new simulated environment designed to generate human depth data in a multi-view environment. This system presents the advantage of a pose capture space and is used to perform transfer learning on a voxel-based deep neural network. This work exemplifies the usefulness of simulated data when real-world data is scarce. In completing this work I have generated two new datasets, the extended MHAD dataset, based on real-world depth data, and the Human Motion Depth Dataset (HuMoD), both of which will be made available to the public
Millimeter-wave and terahertz subharmonic CMOS transmitters
No full textThe terahertz frequency spectrum has become a focal point for next-generation communication, sensing, and imaging systems. There is a pressing need for compact, power-efficient, and integrable transmitter architectures. Conventional transistor-based solutions face fundamental challenges in achieving high gain and power efficiency at terahertz frequencies due to inherent limitations in carrier transit time in advanced CMOS technologies. Conversely, compound semiconductor technologies, while offering superior high-frequency performance, are often constrained by low fabrication yield and significantly higher cost. These limitations motivate the exploration of reactive frequency-conversion techniques that can overcome the constraints of traditional active circuits.
This dissertation presents a comprehensive study of reactive, multi-port asymmetric varactor-based up-conversion architectures implemented in CMOS process. The proposed designs leverage the nonlinear capacitance characteristics of accumulation-mode MOS varactors to achieve efficient third- and fourth-order subharmonic up-conversion without relying on active devices. By repurposing the varactor’s n-well as an additional signal port, the architecture enables simultaneous injection of local oscillator and intermediate frequency signals without external combiners. This multi-port configuration reduces circuit complexity, minimizes signal loss, and enhances signal-to-signal isolation.
A key contribution of this work is the implementation of a Hartley-inspired quadrature signal-combining network, realized through transmission lines designed to introduce precise phase shifts at both the fundamental and third-harmonic frequencies. The resulting 90º phase relationship between the two asymmetric varactor branches allows intrinsic image and harmonic rejection, improving spectral purity and enabling efficient power combination at the desired output frequency. The dissertation also investigates the impact of bias-dependent harmonic generation and self-biasing effects arising from even-order nonlinearities within the devices. These effects dynamically influence the operating point and impedance environment. Controlled asymmetry in biasing conditions is shown to enhance rejection of undesired harmonics while maintaining constructive combination at the target up-converted frequency.
Beyond its circuit-level innovations, this research establishes a foundational framework for passive terahertz up-conversion in CMOS technology. It addresses key challenges in matching, harmonic control, and bias optimization, offering a pathway toward highly integrated, energy-efficient terahertz transmitters. The proposed approach demonstrates that passive, varactor-based architectures can serve as viable alternatives to power-intensive active circuits
Design and performance evaluation of terahertz passive and dynamic metasurfaces with potential application in 6G
No full textDriven by the need for improved performance and higher data rates, wireless telecommunication technology has undergone continuous evolution since its inception. The next step of its evolution will bring us the sixth-generation (6G) wireless communication technology. Among a multitude of innovative technologies, metasurfaces have the potential to play an important role in realizing 6G technology. Consequently, artificially designed 2D materials, also known as metasurfaces, warrant special attention and detailed investigation into their performance, characteristics, and limitations. In this dissertation, investigations on terahertz static and dynamic metasurfaces have been performed. First, the design of a broadband static metasurface-based focusing device is presented, and its dispersion behavior is studied. Then, a low-Fresnel-number, broadband, and highly efficient focusing metamirror has been presented, its experimental evaluation has been presented, and the reasons for its high performance metrics have been discussed. Additionally, a metasurface-based focusing mirror has been presented to address the focal shift issue in low Fresnel number optics. It has been demonstrated that this metamirror, operating in broadband, is capable of correcting focal shifts more effectively than an ideal mirror. Finally, an air-gap tunable beam steering metadevice has been presented, experimentally evaluated, and its working principle and limitations have been explained in terms of the dynamic blazed grating mechanism. The results of the investigations on dispersion behavior of metasurfaces-based optics, benefits and limitations of low-Fresnel number optics, and mechanisms and limitations of dynamic metasurfaces are critical in designing metasurface-based optics and devices for the next generation
wireless communication technology
Effect of extracorporeal shockwave therapy on pain reduction and improved functional outcomes for greater trochanteric tendinopathy: A critically appraised topic
No full textIntroduction/Objectives: Chronic greater trochanteric tendinopathy (GTT) is a significant musculoskeletal condition, particularly affecting athletes involved in long-distance or repetitive highimpact activities. Characterized by lateral hip pain and functional impairments, it poses substantial challenges to athletic performance and recovery. Traditional interventions, including strengthening, stretching, and load management, often result in suboptimal success. This Critically Appraised Topic (CAT) examines the efficacy of extracorporeal shockwave therapy (ESWT) in reducing pain and improving functional outcomes in athletes with chronic GTT.Methods: A systematic search of PubMed, EBSCOhost, CINAHL, and SPORTDiscus was conducted. Studies meeting inclusion criteria focused on athletes with GTT, utilized ESWT as an intervention, and reported pain reduction and functional improvement outcomes. Four high-quality studies, including three randomized controlled trials (RCTs) and one retrospective cohort study, were identified and analyzed. Evidence levels were assessed using the Oxford Center for Evidence-Based Medicine (OCEBM) and the Physiotherapy Evidence Database (PEDro) scale.Results: ESWT significantly reduced pain and improved function in GTT patients, particularly when paired with therapeutic exercise. Level 2 evidence from randomized controlled trials highlighted longterm benefits, while retrospective cohort data supported its sustained efficacy. Specific improvements included reductions in visual analog scale (VAS) pain scores and enhanced lower extremity functional scale (LEFS) outcomes.Conclusions: ESWT is a promising, non-invasive intervention for managing GTT. It offers significant pain relief and functional improvements, enhancing athlete care and recovery. Further research is recommended to standardize treatment protocols, validate biomarkers for tendon healing, and optimize clinical applications
Electronic medical record study of the rate of CT and MRI scanning of female victims of nonfatal strangulation for identification of brain injury
No full textBackground: In the US, 1 in 6 adult women will experience non-fatal strangulation (NFS) such as choking or suffocation in their lifetimes. NFS is a severe form of intimate partner violence (IPV), characterized by external pressure on the neck that can lead to hypoxic injuries which can be classified as a type of injury to the brain including traumatic brain injury (TBI). Brain injuries are best identified through CT and MRI scanning, MRI being far superior. To date the appropriate, standardized care for NFS victims allows for clinician’s judgement as to the medical necessity of CT or MRI scans to identify brain injury. It is unknown the extent to which clinicians seek those scans after an assault diagnosis in women.Objective: This study aims to assess the rate of documented CT and MRI imaging procedures (representing a clinician decision to assess for brain injury beyond physical assessment) among female patients with a documented diagnosis of strangulation from assault.Methods: The data was extracted from Cerner Health Facts, one of the largest HIPAA-compliant relational databases. To extract female patients most likely to have suffered from domestic assault, we used the ICD9 code 994.7 and ICD9 code E963 to clearly identify those patients suffering from assault strangulation. We limited age to 13 years and older. Patients with unknown age were excluded.Results: The data query (from the Cerner Realdataset) identified 160 female patients aged 13 to 65 (M = 32, Std dev = 13.61) . Twelve women (7.5%) received a CT of head (combined CPT codes 87.03 and 70450) and none were coded as receiving an MRI of the head. Frequency of treatment location was as follows: 95 (59%) in the emergency room, 45 (28%) in inpatient care, 7 (4%) in observation unit, and 6 (4%) in an outpatient clinic.Conclusion: The sample size of the study was extremely low given the 85+ million unique patients in the dataset; our conclusion was that physicians do not code for NSF assault, making studying treatment of assault victims difficult. Therefore, next steps in understanding treatment of NFS victims will include treatment of NFS broadly.Using the frequency of CT and MRI scans as a proxy for clinical interest in understanding and identifying injury to the brain after strangulation,it appears that brain injury detection through imaging is not yet a routine focus, suggesting that the standard of care for NFS patients’ needs further establishment. Since there is no standardized care requiring scanning (even though brain injury can occur without external strangulation signs), we cannot conclude inappropriate treatment was delivered. Changes to appropriate care standards may be necessary.Given the extremely low rate of CT or MRI imaging at the initial time of treatment, we wonder what educational discharge material patients are provided to raise their awareness of their risk of brain injury. To explore patient education, these researchers are currently conducting an OSU CHS IRB approved study of Oklahoma hospital systems’ embedded patient education provided post asphyxiation and strangulation