Treasures @ UT Dallas

Welcome to Treasures @ UT Dallas Institutional Repository, established in 2010. Treasures is a resource for our community to showcase, organize, share, and preserve research and scholarship in an Open Access repository.


Recent Submissions

Low Noise Integrated Circuits and Systems Using Nano-Scale MOSFETs and Intelligent Post-Fabrication Selection
(December 2021) Yelleswarapu, Venkata Pavan Kumar; O, Kenneth K.; Venkatesan, Subbarayan; Henderson, Rashaunda; Ma, Donsheng Brian; Makris, Yiorgos
Recent advances in integrated radio design have enabled many applications such as wearable healthcare, 5G communication, and beyond 5G or 6G applications for ultra-high data rate communications, high-resolution imaging, sensing, and spectroscopy. All these applications require low noise radio transceivers for achieving high performance. For example, applications requiring high data rate and higher order modulation schemes need to achieve high signal to noise ratio (SNR) and therefore a low noise figure to maintain a low bit-error rate (BER). In addition, noise phenomena like jitter and phase noise can impact the critical parameters like maximum achievable data rate and energy efficiency. This research aims to improve the noise performance of integrated circuits and systems through intelligent post-fabrication selection of an array of nanoscale transistors sized near the minimum in CMOS processes. A phase noise reduction technique in LC Voltage Controlled Oscillators (VCO’s) is demonstrated by post-fabrication selection of a subset of an array of near minimum-size cross-coupled transistor pairs with reduced low frequency noise and thermal noise. The technique reduces the phase noise by taking advantage of the fact that when transistor dimensions are reduced, the low frequency noise and thermal noise vary significantly. Applying an intelligent post-fabrication selection process using a genetic algorithm, the lowest phase noise of -122 dBc/Hz, -127 dBc/Hz, -137.5 dBc/Hz at 600-kHz, 1-MHz, and 3-MHz offsets, respectively from a 3.8-GHz carrier has been measured. The VCO prototype was fabricated in a 65-nm CMOS process and dissipates 7 mW of DC power. The maximum figure of merit (FoM) including phase noise, carrier frequency and power consumption is 191 dBc/Hz and the figure of merit including the VCO core area, FoMA is 207 dBc/Hz. A technique is demonstrated to reduce both the in-band and out-of-band phase noise of a 4-GHz Integer-N PLL by employing an array of individually selectable cross-coupled pairs formed using near minimum-size transistors in an LC VCO and intelligent post-fabrication selection. By reducing both the in-band and out-of-band phase noise, the overall integrated phase jitter in a frequency synthesizer can be minimized. Applying an intelligent post-fabrication selection process, the lowest phase noise of -72 dBc/Hz at 30-kHz offset, -106 dBc/Hz at 300-kHz offset, -121.8 dBc/Hz at 1-MHz offset, and -132.5 dBc/Hz at 3-MHz offset, respectively from a 4.01-GHz locked carrier has been measured. The integrated rms jitter from 100-kHz to 100-MHz offsets is 440 fs. A mixer-first downconverter employing an array of passive mixers formed using near minimumsize transistors and intelligent post-fabrication selection achieves a double sideband noise figure of 4.2 dB at RF of 6 GHz, which is the lowest at 6 GHz for CMOS mixer-first downconverters. The downconverter is fabricated in 65-nm CMOS and demonstrates out-of-band IIP3 and IIP2 of 25 dBm and 65 dBm, respectively at 80-MHz IF, while dissipating 11.5 mW. Post-fabrication selection is performed by a genetic algorithm which takes ~17 generations to converge to the combinations exhibiting the lowest noise.
Causarum Cognitio: the Architecture, Collections, and Social Agency of Three American Athenaea: Redwood, Boston, and Caltech
(December 2021) Curry, Virginia; Schulte, Rainer; Gooch, John; Channell, David; Schlereth, Eric; Schich, Maximilian
Is the athenaeum an adaptable concept in the twenty-first century university environment? What evidence exists to conclude that it contributes to a discursive community? This dissertation explores the legacy of the concept of the athenaeum in America and examines the organically formed social circles who share an interest in continuing discourse, often within multiple disciplines, and who contribute to their communities by modeling habits and behaviors reflecting their desire for improvement of themselves and their communities. From before and since our nation’s founding, the societies of the American Athenaeum have served as community-organized intellectual and artistic hubs, providing access to information, pursuing thought-provoking discourse, and applying their aggregate knowledge resources as agency for social change while presenting the most inspirational architecture, lectures, artistic performances, and collections to their communities. I focus on the eighteenth century Redwood Library and Athenaeum of Newport, Rhode Island, the nineteenth century Boston Athenaeum, and the twentieth century Caltech Athenaeum. The newest of these, Caltech Athenaeum, has been in service over one hundred years, and the oldest, the Redwood Library and Athenaeum, has been in service to its community continuously over 300 years.
‘Send More Butter’: Finding Meaning in Civil War Food References
(December 2021) Jacobs, Janet Kathleen; Wright, Ben; Veras, Christine; Ring, Natalie J.; Barnes, Ashley; Stewart, Whitney
Food in the American Civil War meant more than nutrition. It served as a means of communication, status elevator, social lubricant, and bridge between home and front, and even across battle lines. This work examines how food, cooking, and references to food can be interpreted to tell us more about how the war operated on different levels. Approached thematically, the study looks at express boxes, mess bonding, cooking, social hierarchy of cooks, the blockade, and trade across lines. Central to the argument is that food references in Civil War letters acted as a subtle communications tool that give insight into how soldiers felt and responded to the historic events around them. Essentially, it seeks to decode the language of food in Civil War letters. In addition to the letter diagnostics, the study takes a food-centric look at Sherman’s actions in Georgia and the Carolinas in 1864-65, with an eye toward how his seizure and destruction of the resources can be interpreted, and why he felt so confident in his success. Another intervention involves the express boxes and how they connected the home front and the war front. By examining tax data, it becomes clear that many more boxes were sent to the front than previously estimated, which changes how we should approach these gifts and civilian contributions to the war effort. Food is also used as a lens into the blockade, women’s resistance, and the formation of bonds between soldiers. Cooking is examined for its ability to change the social status of meal preparers, both white and Black, free and enslaved. Cooking changed attitudes and lives during the war, even as it is suspected to have ended others. Food is more than calories and comfort, it is also a means of communication, identity, commerce, and social tie. Through this perspective, the Civil War takes on fresh nuances.
Accountability Overload and Its Consequence and Remedy
(December 2021) Rabbi, Md Fazle; Sabharwal, Meghna; Giertz, Seth; Harrington, James R; Gorina, Evgenia; McCaskill, John R.
Accountability overload (AO) may increase cost, lower responsiveness, and decrease productivity and service quality [103]. It creates an extra burden on employees [163], erodes their trust and morale [185], and decreases their job satisfaction [43]. Specifically, it undermines organizational mission [15, 68] and performance [140, 152, 155]. However, the examination of the phenomenon and its consequence and remedies is still in a nascent stage and predominantly qualitative. This dissertation undertakes three interrelated studies to fill the research gap by advancing the concept, empirically examining the relationship between AO and organizational outcome, and exploring remedies to AO. The first study conducts a systematic review of Public Administration literature on AO. The second study empirically examines the relationship between AO and the performance of public servants across societal cultures. The third study investigates the effect of ethical leadership (EL) on AO and the mediating role of the ethical environment (EE) on the relationship between EL and AO. The first study identifies the elements of AO and its consequence and remedy. The most common element of AO is multiple accountabilities or expectations. Besides, incompatibility between accountability criteria and organizational goals, ambiguous performance standards, and excessively high accountability or performance requirements are some of the dominant elements of AO. In addition, episodic and arbitrary accountability demand, incomplete outcome measures, emphasis on punitive actions, and lack of legitimacy of the accountholder are the factors that contribute to AO. The study suggests that AO generally produces negative consequences: it undermines performance and organizational objectives and makes the accountability system ineffective. Collaboration and dialogue, moderate accountability requirements, appropriate performance criteria, ethical practice in the organization, and an emphasis on the organizational mission may reduce AO. Contextual factors such as poor governance and lack of trust in government influence AO in the organization. However, extant studies are predominantly qualitative and concentrated in a limited number of countries. Thus, the study emphasizes empirical investigation into AO in comparative settings to appreciate the phenomenon and its consequences and remedies. The second study defines perceived AO and finds a negative association between AO and employee performance. It also proves that the relationship between performance and AO does not vary across societal cultures. Therefore, the study concludes that AO is a universal phenomenon and has a similar consequence irrespective of differences in contexts or cultures. The third study finds that EL reduces AO among employees and enhances EE in the organization. However, EE does not influence the relationship between EL and AO. Thus, the study underscores the importance of EL in reducing AO among employees irrespective of the ethical condition in the organization.
Investigation of Sweat Biomarkers for Real-time Reporting of Infection and Inflammation Using Wearable Sweat Sensor
(December 2021) Jagannath, Badrinath; Prasad, Shalini; Bereg, Sergey; Muthukumar, Sriram; Sirsi, Shashank; Khoubrouy, Soudeh
Inflammatory biomarkers are modulated due to an infection or inflammatory trigger. Cytokines are inflammatory biomarkers that orchestrate the manifestation and progression of an infection/inflammatory event. Hence, non-invasive, real-time monitoring of cytokines can be pivotal in assessing the progression of infection/inflammatory event. However, real-time monitoring of biomarkers is not feasible with the current technology as most of them rely on blood-based detection. Continuous monitoring of host immune markers in sweat can aid in realtime monitoring of the immune status. This dissertation demonstrates a wearable SWEATSENSER device that can track the levels of immune cytokine markers in real-time from passively expressed sweat. The developed device is of a watch form-factor that can be worn on the arm to reliably track the biomarker response from low volumes of sweat (~1 μL) and the biomarker levels can be monitored in real-time. The developed SWEATSENSER device was validated for reliably reporting the levels of several cytokines and chemokines. Additionally, this work presents a thorough validation on the presence of certain critical infection and inflammatory markers such as interferon-inducible protein (IP-10) and tumor necrosis factor- related apoptosis-inducing ligand (TRAIL), C-reactive protein that make it feasible for using sweat as a biofluid for actively monitoring the health status. Additionally, human subject clinical studies demonstrate the feasibility of non-invasively tracking infections such as influenza from sweat. Such a wearable device can offer significant strides in improving prognosis and provide personalized therapeutic treatment for several inflammatory/infectious diseases.