2019 UMKC Theses - Freely Available Online
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Item Frequency and Field Strength Materials Characterization with Complementary Split-ring Resonators, Coplanar Waveguides, and the Virtual Ground Method(University of Missouri -- Kansas City, 2019) Chandler, Daniel; Caruso, Anthony N.In the radiofrequency bands, measuring the power-dependent complex permittivity and permeability of materials that undergo metal–insulator transitions is a significant challenge which is important for defense and commercial applications. This thesis attempts to articulate barriers in the prior art, and how the techniques described herein overcome such deficiencies. Specifically, using a combination of direct and indirect narrow-band resonant and wide-band, non-resonant heterostructures, with narrow gaps, application relevant electric fields were achieved, and complementary assessments of the measured S-parameters were determined. The heterostructures/fixtures include complementary split-ring resonator and coplanar waveguide instantiations. Additionally and complementary to the RF measurement systems, a ferroelectric test measurement system for high-frequency and high-power polarization vs. electric field curves was designed, built, tested, and shown to match baseline comparisons. The ferroelectric test system is a Sawyer–Tower variant using the virtual ground topology.Item Identifying personality and topics of social media(2019) Muppala, Trinadha Rajeswari; Lee, Yugyung, 1960-Twitter and Facebook are the renowned social networking platforms where users post, share, interact and express to the world, their interests, personality, and behavioral information. User-created content on social media can be a source of truth, which is suitable to be consumed for the personality identification of social media users. Personality assessment using the Big 5 personality factor model benefits organizations in identifying potential professionals, future leaders, best-fit candidates for the role, and build effective teams. Also, the Big 5 personality factors help to understand depression symptoms among aged people in primary care. We had hypothesized that understanding the user personality of the social network would have significant benefits for topic modeling of different areas like news, towards understanding community interests, and topics. In this thesis, we will present a multi-label personality classification of the social media data and topic feature classification model based on the Big 5 model. We have built the Big 5 personality classification model using a Twitter dataset that has defined openness, conscientiousness, extraversion, agreeableness, and neuroticism. In this thesis, we (1) conduct personality detection using the Big 5 model, (2) extract the topics from Facebook and Twitter data based on each personality, (3) analyze the top essential topics, and (4) find the relation between topics and personalities. The personality would be useful to identify what kind of personality, which topics usually talk about in social media. Multi-label classification is done using Multinomial Naïve Bayes, Logistic Regression, Linear SVC. Topic Modeling is done based on LDA and KATE. Experimental results with Twitter and Facebook data demonstrate that the proposed model has achieved promising results.Item Predicting Personal and Relational Recovery from Infidelity in Committed Relationship: A Moderated Mediation Model(2019) Ng, G Wei; Murdock, Nancy L.Infidelity can be damaging to committed relationships and is the most frequently cited cause of divorce (Austin Institute, 2014). Evidence suggests that couples can survive the trauma of infidelity, and that recovery is possible (Heintzelman, Murdock, Krycak, & Seay, 2014; Olson, Russell, Higgins-Kessler, & Miller, 2002); however, the recovery process following the disclosure of infidelity remains an under-studied area in the infidelity literature. The present study, informed by attachment theory, infidelity literature, and forgiveness research, used a moderated mediation model analyzing the contribution of attachment style, socio-cognitive correlates (i.e. rumination, attribution, and empathy), and perceived partner empathy to personal and relational recovery from infidelity among a sample of individuals who chose to remain in the relationship in which the infidelity occurred. Path analytic findings revealed that (a) the attachment anxiety – forgiveness link was partially mediated by rumination, but not attribution, whereas the attachment avoidance – forgiveness link was partially mediated by low empathy; (b) perceived partner empathy did not moderate the relation between attachment and rumination, attribution, and empathy; (c) perceived partner empathy, but not attachment anxiety, predicted lower non-benign attribution, and was directly or indirectly related to all four recovery outcomes; and (d) forgiveness was a significant second-order mediator in relationships between insecure attachment and other distal recovery outcomes including psychological distress, relationship satisfaction, and relational trust. Implications are discussed.Item Association of chronic self-perceived stress with mortality and health status outcomes in patients with peripheral artery disease: insights from the portrait registry(2020) Malik, Ali Osama; Smolderen, Kim G.The prevalence of peripheral artery disease (PAD) is increasing worldwide and is estimated to affect about 360 million patients by 2030. Patients with PAD are at a higher risk of premature mortality and suffer from disability and functional impairment, both of which contribute to the direct and indirect socioeconomic burden of PAD. These trends are occurring despite emphasis towards control of traditional risk factors and interventions to decrease the impact of PAD on patient outcomes. Hence it is critical to identify and study novel risk factors that could impact outcomes in patients with PAD. Chronic mental stress could be one such factor. Mental stress is a potent cardiovascular risk factor and has been associated with development and progression of coronary disease and worse outcomes, including higher risk of mortality and poorer quality of life in patients after a myocardial infarction. However, there is paucity of evidence for the association of chronic mental stress with outcomes in PAD. To address this critical gap in understanding the link between mental stress and outcomes in PAD, we used data from the Patient-centered Outcomes Related to Treatment practices in peripheral Arterial disease: Investigating Trajectories (PORTRAIT), an international registry of patients presenting with symptoms of PAD. Mental stress was quantified at baseline, 3-, 6- and 12-month follow-up using the validated 4-item Perceived Stress Scale (PSS-4). For each patient available PSS-4 scores from all time points were averaged to quantify a subject’s average exposure to mental stress over one year. To examine the association of chronic stress with longitudinal mortality and health status outcomes, we did two separate landmark analysis. First to examine the impact of chronic stress on mortality we did a landmark analysis starting at 12-month follow-up. For each patient we defined chronic stress to be average of PSS-4 score at baseline through 12-months. Cox regression models adjusting for patients’ demographics (age, sex, race), comorbid conditions (diabetes, hypertension, history of myocardial infarction, congestive heart failure, smoking status), baseline ankle-brachial index, invasive treatment for PAD, socioeconomic indicators (highest education level, avoidance of care due to cost and end of the month resources), were used to assess an independent association of average stress (over first year of follow-up) with all-cause mortality over the subsequent four years. Second, to examine the association of chronic stress with 12-month health status outcomes we defined chronic stress exposure to be average PSS-4 score across baseline, 3- and 6-month follow-up assessments. This quantified a patient’s exposure to chronic stress over first 6-months of follow-up. Health status was quantified at baseline and 12-months. PAD specific health status was assessed using the PAD Questionnaire (PAQ). Generic health status was assessed using the EuroQoL Visual Analog Scale (EQ5D VAS). Hierarchical multivariable regression models, with random effects for site and adjustment for country, patients’ demographics, comorbid conditions, baseline ABI, treatment strategy and socioeconomic status-were used to examine independent association of average stress (baseline to 6-months) on recovery in health status at 12-months. In in patients in whom accurate assessment of chronic mental stress and mortality could be made (n=757, mean age 68.5 ± 9.7, 42% females, 28% non-Caucasians), higher average stress scores over 12-months were associated with greater hazards of mortality, in the adjusted model (hazard ratio per +1 unit increase in average PSS-4 1.08, 95% CI 1.01, 1.16 p=0.03). Similarly, in patients who had complete assessment of chronic stress over 6-months and health status at baseline and 12-month follow-up (n=1060, mean age 67.7, 37% females, 17.7% non-Caucasian) higher averaged stress scores over 6-months were associated with poorer PAQ summary score at 12-months in completely adjusted models (-1.4 points per +1-point increase in average PSS-4 95% CI -2.1, -0.6 p <0.001). Chronic stress in patients with PAD, is independently associated with higher mortality risk and poorer health status outcomes. These results set the stage for exploring interventions to examine if strategies to reduce chronic stress in patients with PAD improves outcomesItem Static random-access memory designs based on different FinFET at lower technology node (7nm)(2019) Nizam, Athiya; Chowdhury, Masud H.The Static Random-Access Memory (SRAM) has a significant performance impact on current nanoelectronics systems. To improve SRAM efficiency, it is important to utilize emerging technologies to overcome short-channel effects (SCE) of conventional CMOS. FinFET devices are promising emerging devices that can be utilized to improve the performance of SRAM designs at lower technology nodes. In this thesis, I present detail analysis of SRAM cells using different types of FinFET devices at 7nm technology. From the analysis, it can be concluded that the performance of both 6T and 8T SRAM designs are improved. 6T SRAM achieves a 44.97% improvement in the read energy compared to 8T SRAM. However, 6T SRAM write energy degraded by 3.16% compared to 8T SRAM. Read stability and write ability of SRAM cells are determined using Static Noise Margin and N- curve methods. Moreover, Monte Carlo simulations are performed on the SRAM cells to evaluate process variations. Simulations were done in HSPICE using 7nm Asymmetrical Underlap FinFET technology. The quasiplanar FinFET structure gained considerable attention because of the ease of the fabrication process [1] – [4]. Scaling of technology have degraded the performance of CMOS designs because of the short channel effects (SCEs) [5], [6]. Therefore, there has been upsurge in demand for FinFET devices for emerging market segments including artificial intelligence and cloud computing (AI) [8], [9], Internet of Things (IoT) [10] – [13] and biomedical [17] –[18] which have their own exclusive style of design. In recent years, many Underlapped FinFET devices were proposed to have better control of the SCEs in the sub-nanometer technologies [3], [4], [19] – [33]. Underlap on either side of the gate increases effective channel length as seen by the charge carriers. Consequently, the source-to-drain tunneling probability is improved. Moreover, edge direct tunneling leakage components can be reduced by controlling the electric field at the gate-drain junction . There is a limitation on the extent of underlap on drain or source sides because the ION is lower for larger underlap. Additionally, FinFET based designs have major width quantization issue. The width of a FinFET device increases only in quanta of silicon fin height (HFIN) [4]. The width quantization issue becomes critical for ratioed designs like SRAMs, where proper sizing of the transistors is essential for fault-free operation. FinFETs based on Design/Technology Co-Optimization (DTCO_F) approach can overcome these issues [38]. DTCO_F follows special design rules, which provides the specifications for the standard SRAM cells with special spacing rules and low leakages. The performances of 6T SRAM designs implemented by different FinFET devices are compared for different pull-up, pull down and pass gate transistor (PU: PD:PG) ratios to identify the best FinFET device for high speed and low power SRAM applications. Underlapped FinFETs (UF) and Design/Technology Co-Optimized FinFETs (DTCO_F) are used for the design and analysis. It is observed that with the PU: PD:PG ratios of 1:1:1 and 1:5:2 for the UF-SRAMs the read energy has degraded by 3.31% and 48.72% compared to the DTCO_F-SRAMs, respectively. However, the read energy with 2:5:2 ratio has improved by 32.71% in the UF-SRAM compared to the DTCO_F-SRAMs. The write energy with 1:1:1 configuration has improved by 642.27% in the UF-SRAM compared to the DTCO_F-SRAM. On the other hand, the write energy with 1:5:2 and 2:5:2 configurations have degraded by 86.26% and 96% in the UF-SRAMs compared to the DTCO_F-SRAMs. The stability and reliability of different SRAMs are also evaluated for 500mV supply. From the analysis, it can be concluded that Asymmetrical Underlapped FinFET is better for high-speed applications and DTCO FinFET for low power applications.