Dissertation Defense Announcements

The real, complex network environment consists of an ever-increasingly diverse and large amount of data encapsulated in packets. Surveillance and monitoring of this traffic is a necessary task for law enforcement, cybersecurity, and intelligence agencies. Intercepted network traffic must be classified into multiple categories, such as the protocol encapsulation layers contained, application it originates from, user generating the traffic, and the traffic's malicious or benign nature. There is a lack of solutions which are able to classify packets individually without flow-based features. In order to address the gaps in current traffic classification and DPI techniques, we propose the initial release of the Forager toolkit, a software consisting of tools to extract hidden representations from individual packets and use these features in deep learning models to perform traffic classification. It uses data mining techniques to perform automatic generation of regular expression signatures, locality-sensitive hash fingerprints, and matrix and point cloud representations of packets. These are used as input features for corresponding deep learning models which can perform traffic classification on single packets in a real system. The models are multi-modal to capture multiple angles and dimensions of features for increased complexity of classification problems. They can be run in parallel for optimal throughput and scalability. Our experiments use these models in multiple configurations and scenarios to demonstrate superior performance and classification capability to advance the state of the art in complex network traffic surveillance and hidden representation learning.

Trauma-informed care has been the subject of numerous scholarly studies in various contexts for nearly four decades. Thus, TIC practices have been shown to reduce educators' stress (Jaycox et al., 2019), increase teacher awareness of student trauma experiences (Kuhn et al., 2019; McIntyre et al., 2019), and improve teachers' self-confidence in engaging with and helping students with trauma (Gruman et al., 2013). However, while most education research has focused on how school personnel can implement trauma-informed practices, no research supports the comprehension of the lived experiences of K-12 trauma-trained teachers who implement TIC intervention strategies in their classrooms. This study aimed to explore the lived experiences of trauma-trained K-12 teachers that have incorporated TIC intervention strategies within their classrooms to help understand their perceptions of the impact of trauma training and the use of TIC intervention strategies. The researcher used a purposive sampling and semi-structured interview format to investigate the experiences of six trauma-trained K-12 teachers using TIC intervention approaches in their classrooms. The results generated four major themes: The Impact of Training, Implemented TIC Strategies and Practices, Factors and Practices Contributing to Trauma-Informed Education, and Challenges. All the themes were fundamental to answering the research question related to lived experiences and perceptions of trauma-trained teachers. In an attempt to tackle ACE among K–12 students, this study provides implications and recommendations for future research that may improve the efficacy of TIC intervention strategies among teachers and school counselors.

Power electronics converters are an integral part of modern power and energy system. Power semiconductor switching devices are the most significant component in a power electronics converter. Power semiconductor devices such as MOSFETs/IGBTs age through different degradation mechanisms in long-term applications. Failure of MOSFETs/IGBTs is one of the primary causes of power electronics failure. And MOSFETs on-state resistance (RDSON) is a key health-indicating parameter. This dissertation presents sensing circuit designs that enable real-time monitoring of on-state voltage of the MOSFETs/IGBTs. In addition a complete online in-situ health monitoring system of the MOSFETs in a three-phase inverter is presented. A new on-state drain-source voltage (VDSON) sensing circuit has been used to monitor the RDSON of the high-side MOSFETs. This sensor references the drain of the high-side transistors for their VDSON measurement and allows VDSON measurement of multiple high-side transistors with respect to the same ground reference. The high-side VDSON measurement circuits combined with low-side VDSON measurement circuits have been used for a complete RDSON monitoring of all the MOSFETs in the inverter. The drain current (IDS) is captured from measurements using an off-the-shelf current sensor located at the output filter inductor. Accounting for propagation delays in the measurement circuitry, both the VDSON and IDS are sampled and converted into digital data multiple times in a switching cycle, filtered, and stored in a digital signal processor (DSP). The DSP, originally used for the inverter control, then processes the sensor data captured over one grid cycle and calculates the average RDSON of the MOSFETs of the inverter. Validations of all the sensing circuits, using theoretical analysis and hardware experiments along with the software implementation for data processing and handling are presented in the dissertation for this real-time, in-situ RDSON measurement. Furthermore, a method of mapping the MOSFET's RDSON to the junction temperature is presented which can be used for real-time accurate junction temperature estimation of the MOSFETs.

Sexual violence on college campus is a salient threat to the health and well-being of students in higher education. Title IX legislation was developed to address and help reduce sex-based discrimination, including incidences of sexual violence, on college campuses. However, existing data suggests that a relatively small number of campus survivors make a formal report and subsequently have an interaction with the Title IX Office (Cantor et al., 2015). Additionally, little is known about the implementation of Title IX processes, the nature of Title IX sexual violence reports, or the outcomes of survivors involved in Title IX reports. The current study adds to our understanding of these survivors’ experiences. Specifically, the study utilized archival Title IX report data obtained from one large public university during the 2018-2019 and 2019-2020 academic years (n = 151) to explore the nature and scope of Title IX sexual violence reports and the academic health outcomes of survivors post-report. The study utilized data extracted from Title IX sexual violence reports to describe the characteristics of Complainants (i.e., survivors), Respondents (i.e., perpetrators), incident characteristics, reporting processes, and characteristics of cases involved in formal university hearings. The study also utilized aggregated data from the Title IX sexual violence reports in conjunction with data obtained from UNC Charlotte Maxient system, which contains student GPA and enrollment status, to examine the academic health of survivors over time. Complainants predominantly identified as Caucasian (65%) and female (93%). Respondents predominantly identified as Caucasian (42%) and male (99%). Complainants most often identified Respondents as friends (16%), ex romantic partners (16%), or acquaintances (14%). Only 11% of Respondents were identified as strangers. Complainants were most often referred to the Title IX Office by mandated reporters (87%). Over half of the Complainants (62%) engaged with Title IX staff following initial outreach. Many cases had incomplete academic data (no pre-report or post-report semester GPA). However, in the sample with three GPA time points (n = 57 survivors), academic outcomes over time were not significantly associated with Respondent’s affiliation to the university, source of referral to the Title IX Office, engagement in the reporting process, or involvement in a formal university hearing. Seventeen percent (n = 25) of Complaints dropped out of the university. However, Complainant engagement with the Title IX Office was not significantly associated with dropout. These findings increase our understanding of the Title IX process and the experiences of campus sexual assault survivors who are involved with the Title IX Office.