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Title: Nate Thomas, Illinois Institute of Technology, Chicago, IL, 1968-1973
Date: 1968-1973
Description: Photograph of Nate Thomas. Thomas worked at Illinois Tech in various positions, first as part of the Computing Center in 1965. Thomas later...
Show morePhotograph of Nate Thomas. Thomas worked at Illinois Tech in various positions, first as part of the Computing Center in 1965. Thomas later served as Assistant Director of Co-Op Education , Director of Admission, head of Minority Affairs, and Vice President for External Affairs. Thomas was instrumental in recruiting students from underserved communities into STEM programs at Illinois Tech, and founded the Early Identification program in 1974 in order to attract and support diverse students interested in STEM, architecture, and other programs at Illinois Tech. Photographer unknown. Date of photograph is unknown. Date range listed is approximate.
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Collection: Office of Communications and Marketing photographs, 1905-1999

Title: Nate Thomas, Illinois Institute of Technology, Chicago, IL, 1968-1973
Date: 1968-1973
Description: Photograph of Nate Thomas. Thomas worked at Illinois Tech in various positions, first as part of the Computing Center in 1965. Thomas later...
Show morePhotograph of Nate Thomas. Thomas worked at Illinois Tech in various positions, first as part of the Computing Center in 1965. Thomas later served as Assistant Director of Co-Op Education , Director of Admission, head of Minority Affairs, and Vice President for External Affairs. Thomas was instrumental in recruiting students from underserved communities into STEM programs at Illinois Tech, and founded the Early Identification program in 1974 in order to attract and support diverse students interested in STEM, architecture, and other programs at Illinois Tech. Photographer unknown. Date of photograph is unknown. Date range listed is approximate.
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Collection: Office of Communications and Marketing photographs, 1905-1999

Title: The Cycle, 1931
Creator: Armour Institute of Technology
Date: 1931
Description: Volume 19 of The Cycle, the 1931 yearbook for the Armour Institute of Technology. The Armour Institute of Technology yearbooks was known by...
Show moreVolume 19 of The Cycle, the 1931 yearbook for the Armour Institute of Technology. The Armour Institute of Technology yearbooks was known by three different titles: Integral (1898-1910), Senior Class Book (1911-1912), and The Cycle (1913-1940). A 1902 volume of Integral is not a part of Galvin Library collections; it is uncertain of a yearbook was published that year. Publication of the Armour Institute ceased in 1941, when the Armour Institute of Technology merged with the Lewis Institute to form Illinois Institute of Technology.
Sponsorship: Scanning of the Armour Institute of Technology yearbooks was supported in part by an award from the Illinois State Historical Records Advisory Board, through funding from the National Historical Publications and Records Commission, National Archives and Records Administration.
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Collection: Armour Institute of Technology yearbooks, 1898-1940

Title: The Cycle, 1920
Creator: Armour Institute of Technology
Date: 1920
Description: Volume 8 of The Cycle, the 1920 yearbook for the Armour Institute of Technology. The Armour Institute of Technology yearbooks was known by...
Show moreVolume 8 of The Cycle, the 1920 yearbook for the Armour Institute of Technology. The Armour Institute of Technology yearbooks was known by three different titles: Integral (1898-1910), Senior Class Book (1911-1912), and The Cycle (1913-1940). A 1902 volume of Integral is not a part of Galvin Library collections; it is uncertain of a yearbook was published that year. Publication of the Armour Institute ceased in 1941, when the Armour Institute of Technology merged with the Lewis Institute to form Illinois Institute of Technology.
Sponsorship: Scanning of the Armour Institute of Technology yearbooks was supported in part by an award from the Illinois State Historical Records Advisory Board, through funding from the National Historical Publications and Records Commission, National Archives and Records Administration.
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Collection: Armour Institute of Technology yearbooks, 1898-1940

Title: Quantification of Vascular Permeability in the Retina Using Fluorescein Videoangiography Data as a Biomarker for Early Diabetic Retinopathy
Creator: Kayaalp Nalbant, Elif
Date: 2023
Description: Diabetic retinopathy, which is the most common reason for blindness in the working-age population, affects over one-third of those who have...
Show moreDiabetic retinopathy, which is the most common reason for blindness in the working-age population, affects over one-third of those who have had diabetes for over ten years. High blood sugar level (hyperglycemia) in the blood damages blood vessels and tight junction at the blood-retinal barrier (BRB). Chronic inflammation leads to changes in vascular health, and over time blood vessels tend to get damaged and exhibit higher “leakage” or permeability. In the late stage of DR, hemorrhages can occur, leading to irreversible damage of neuronal tissue in the retina and vision loss. In the clinic, there are some biomarkers and imaging modalities used to diagnose DR based on some of the more severe products of DR (e.g., hemorrhage), but there is no non-invasive, highly sensitive method to detect diabetic retinopathy before clinical signs occur, when mitigating therapies could be more effective. In this thesis, indicator dilution theory was explored to modeling the temporal dynamics of fluorescein in the retina after intravenous injection, with an aim to quantitatively map subtle changes in retinal blood flow and vascular permeability that could preempt subsequent irreversible damage. Specifically, a simplified version of indicator dilution theory—namely the “adiabatic approximation in tissue homogeneity” (AATH) model—was used to estimate physiological parameters such as the blood flow (F) and the extraction fraction (E: a parameter coupled with vascular permeability) from retinal fluorescein videoangiography data. The AATH fitting protocol was optimized through simulations using a more complex model (the AATH-vascular heterogeneity model, AATH-VH). It was determined that a two-step least square fitting method was more sensitive than a single-step least square fitting of AATH to simulated data to evaluate vascular permeability in early diabetic retinopathy. The optimized data analysis protocol was then evaluated in an initial clinical study comparing healthy control subjects to those with moderate non-proliferative DR. Volumetric blood flow and retinal vascular permeability maps were compared between patient groups with clear increases in extraction fraction observed in the mild NPDR patients compared to control. These promising early data have been the foundation to an ongoing 5 year study tracking 100 Diabetic patients with no DR so see if early changes in vascular permeability can predict which patients are more likely to progress to DR.
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Title: Efficient management of uncertain data
Creator: Feng, Su
Date: 2023
Description: Uncertainty arises naturally in many application domains. It can be caused by an uncertain data source (sensor errors, noise, etc.). Data...
Show moreUncertainty arises naturally in many application domains. It can be caused by an uncertain data source (sensor errors, noise, etc.). Data preprocessing techniques (data curation, data integration, etc.) can also results in uncertainty to the data. Analyzing uncertain data without accounting for its uncertainty can create hard to trace errors, with severe real world implications. Certain answers are a principled method for coping with the uncertainty that arises in many practical data management tasks. Unfortunately, this method is expensive and may exclude useful (if uncertain) answers. Other techniques from incomplete database record and propagate more detailed uncertainty information. However, most of these approaches are either too expensive to be practical, or only focus on a narrow class of queries and only work for a specific representation. In this thesis, we investigate models and query semantics for uncertain data management and present a framework that is general and practically efficient, backed up by fundamental theoretical foundations and with formally proven correctness guarantees. We first propose Uncertainty Annotated Databases (UA-DB), which combine an under- and over-approximation of certain answers to combine the reliability of certain answers with the performance of a classical database system. We then introduce attribute-annotated uncertain databases (AU-DB), which extend the UA-DB model with attribute-level annotations that record bounds on the values of an attribute across all possible worlds. AU-DB extends UA-DBs to encode a compact over-approximation of possible answers which is necessary to support non-monotone queries including aggregation and set difference. With a further extension to AU-DB that supports ranking and windowed aggregation queries using native implementation on modern DBMS, our approaches scale to complex queries and large datasets, and produces accurate results. Furthermore, they significantly outperforms alternative methods for uncertain data management.
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Title: High School Mathematics Teachers’ Conceptions of Nature of Mathematics (NOM) and How Prior Learning Environments Affect These Conceptions
Creator: Elefteriou, Katherine
Date: 2023
Description: Literature shows that the Nature of Mathematics Knowledge (NOMK) dates back to the era of Plato and Aristotle (Dossey, 1992). It suggests that...
Show moreLiterature shows that the Nature of Mathematics Knowledge (NOMK) dates back to the era of Plato and Aristotle (Dossey, 1992). It suggests that mathematics teachers’ beliefs, views, conceptions, and preferences about NOM influence the way in which they teach mathematics. It is important to understand how these conceptions are formed, which may evolve consciously or unconsciously from their experiences. Teachers’ experiences as students of mathematics, their family, school environment, cultural, and social experiences influence their behavior including their decisions, actions, class organization, learning activities, and students’ achievement (Beswick, 2012; Ernest, 2008; Thompson1984). Yet, there is no NCTM standard on NOM (Gfeller, 1999).The purpose of the present study was to assess high school mathematics teachers’ NOMK conceptions, and to explore how these conceptions have been influenced by their personal and educational experiences as students in learning mathematics. Another objective of this study was to explore whether the teachers’ years of mathematics teaching experience, and their level of education have any influence on their NOMK beliefs. The sample consisted of 52 high school mathematics teachers, who were certified to teach secondary mathematics, and who had at least three years of mathematics teaching experience. Two instruments were used to collect the data, 1) the VNOM D instrument to assess the teachers’ beliefs regarding the NOMK aspects, and 2) the demographics instrument to collect information on the teachers’ demographics, and on their experiences as students of mathematics. Interviews were also used to enhance the findings. Results showed that participants had strong beliefs regarding their NOMK, and that their years of experience, and level of education influenced their NOMK beliefs.
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Title: Effects of Microstructure Engineering on Laser Powder Bed Fusion Processed Superalloy IN718 through Inoculant Addition
Creator: Ho, I-Ting
Date: 2023
Description: Additive manufacturing (AM) techniques can now be utilized as innovative tools that provide unlimited design flexibility for the fabrication...
Show moreAdditive manufacturing (AM) techniques can now be utilized as innovative tools that provide unlimited design flexibility for the fabrication of geometrically complex metallic structures. For production of Ni-base superalloy components used in advanced gas turbine engines, laser powder bed fusion (L-PBF), which is one of the AM techniques, is frequently used as it allows good metallurgical bonding of powder feedstock and simultaneously enables development of ultra-efficient power systems for aerospace propulsion, space exploration and power generation. One of the major challenges associated with additively manufactured Ni-base superalloy components is that the extreme temperature gradients encountered during processing negatively impact the underlying microstructure and mechanical properties of the material. Although the macroscopic shape and chemistry of the additively fabricated part may be identical to the conventionally manufactured part, the resulting properties are usually compromised. In an effort to make Ni-base superalloys more amenable for processing via additive manufacturing, varying levels of benign inoculants that promote may heterogeneously grain nucleation were blended into Inconel 718 (IN718) powder feedstock and used for processing via L-PBF to characterize the microstructural evolution. In the first study, 0.2 wt. % of micron-sized CoAl2O4 flakes was found to effectively change the grain morphology during the L-PBF process leading to significant reduction in crystallographic texture and thus resulting elastic anisotropy. Dispersion of nano-oxides resulting from the reduction of CoAl2O4 particles also contributed to improved tensile strength and steady creep strain rate. It should be noted, however, that, the multiple iterations of remelting as the result of deposition of new layers dissolved the Co-rich particles reduced from CoAl2O4 inoculants. Instead of having nucleation events contributed by elemental Co, the oxide agglomerates as a result of Marangoni convection seemed to be the major contribution to facilitating grain refinement by inhibiting the heat transfer in the surroundings. On the other hand, addition CoAl2O4 particles appeared to generally reduce the melt pool width while increase the melt pool depth by inhibiting the degree of heat transfer and Marangoni flow. The changes in melt pool dimension aided in improving the relative density and surface roughness of the bulk samples by generating better metallurgical bonding to the subsequent layers. As the trade-off, however, the changes in melt pool physics also enhanced the tendency for epitaxial growth and hence retarded the columnar-to-equiaxed transition unless oxide agglomerates are present. In addition to CoAl2O4, candidates including Co, TaCr2, TiB2, and CeO2 particles were also considered to be blended with the powder feedstock of IN718. After the L-PBF process, different degree of microstructural evolution was characterized with the addition of Co, TaCr2, TiB2, or CeO2 particles. It was found that the physical presence of inoculants may change the melt pool geometries that accounted for a comparatively more columnar-grained structure with <101> texture in samples containing Co and TaCr2 particles while a relatively equiaxed-grained structure with <001> texture in samples containing TiB2. The comparison between samples containing TiB2 and CeO2 further indicates that the phase transformation induced agglomeration will also reduce the effectiveness of inoculants due to decreasing nuclei density. Findings from this investigation demonstrate the resulting grain structure upon L-PBF can be profoundly impacted by both chemistry and physical properties of the inoculants. These effects may potentially be harnessed to effectively engineer the microstructure and optimize the properties of L-PBF processed Ni-base superalloys.
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Title: High-integrity modeling of non-stationary Kalman Filter input error processes and application to aircraft navigation
Creator: Gallon, Elisa
Date: 2023
Description: Most navigation applications nowadays rely heavily on Global Navigation Satellite Systems (GNSSs) and inertial sensors. Both of these systems...
Show moreMost navigation applications nowadays rely heavily on Global Navigation Satellite Systems (GNSSs) and inertial sensors. Both of these systems are known to be complementary, and as such, their outputs are very often combined in an extended Kalman Filter (KF) to provide a continuous navigation solution, resistant to poor satellite geometry, as well as radio frequency interference. Additionally, recent development in safety critical applications (such as aviation) revealed the performance limitations of current algorithms (Advance Receiver Autonomous Integrity Monitoring - ARAIM) to vertical guidance down to 200 feet above the runway (LPV-200). When nominal constellations are depleted, LPV-200 can only sparsely be achieved. Exploiting satellite motion in ARAIM (for instance using a KF) could help alleviate those limitations, but would require adequate modeling of the errors, including the error's time correlation.Power Spectral Density (PSD) bounding is a methodology that provides high integrity, time correlated error models, but this approach is currently limited to stationary errors (which is rarely the case with real data), and has never been applied to navigation errors. More generally, no high integrity, time correlated error models have ever been derived for navigation errors.As a result, in the first part of this thesis, a methodology for high integrity modeling of time correlated errors is introduced. The PSD bounding methodology is extended to both stationary and non-stationary errors. In the second part of this thesis, these methodologies are applied to the 3 main error sources impacting iono-free GNSS measurements (orbit and clock errors, tropospheric errors and multipath), as well as to inertial errors.The methodology introduced in this dissertation provides high integrity time correlated error models and is applicable to any type of applications where high integrity is required (e.g. Differential GNSS - DGNSS, Aircaft Based Augmentation System - ABAS, Ground Based Augmentation System - GBAS, Space Based Augmentation System - SBAS, etc...). Additionally, the error models derived here are not only limited to high integrity applications, but could also be used in applications were the correlation over time of the errors plays an important role (such as any KF integration).In the last part of this dissertation, we focus on a specific safety critical application: aviation, and in particular ARAIM. The dissertation is concluded with an assessment of the performance improvements provided by recursive ARAIM, using those bounding dynamic error models, with respect to those models, used for baseline snapshot ARAIM. Additionally, a sensitivity analysis is performed on each of the error model parameters to assess which of them impacts the KF performance (i.e. covariance) the most.
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Title: A Novel CNFET SRAM-Based Computing-In-Memory Design and Low Power Techniques for AI Accelerator
Creator: Kim, Young Bae
Date: 2023
Description: Power consumption and data processing speed of integrated circuits (ICs) is an increasing concern in many emerging Artificial Intelligence (AI...
Show morePower consumption and data processing speed of integrated circuits (ICs) is an increasing concern in many emerging Artificial Intelligence (AI) applications, such as autonomous vehicles and Internet of Things (IoT). In addition, according to the 2020 International Technology Road map for Semiconductors (ITRS), the high power consumption trend of AI chips far exceeds the power requirements. As a result, power optimization techniques are highly regarded in nowadays AI chip designs. There are various low-power methodologies from the system level to the layout level, and we are focusing on transistor level and register transfer level (RTL) through this thesis. In this thesis, we propose a novel ultra-low power voltage-based computing-in- memory (CIM) design with a new SRAM bit cell structure for AI Accelerator. The basic working principle of CIM (Computing-in-memory) is to use the existing internal embedded memory array (e.g. SRAM) instead of external memory, and it reduces unnecessary access to external memory by calculating with internal embedded mem- ory. Since the proposed our SRAM bit cell uses a single bitline for CIM calculation with decoupled read and write operations, it supports much higher energy eciency. In addition, to separate read and write operations, the stack structure of the read unit minimizes leakage power consumption. Moreover, the proposed bit cell structure provides better read and write stability due to the isolated read path, write path and greater pull-up ratio. Compared to the state-of-the-art SRAM-CIM, our proposed SRAM-CIM does not require extra transistors for CIM vector-matrix multiplication. We implemented a 16k (128⇥128) bit cell array for the computation of 128x neurons, and used 64x binary inputs (0 or 1) and 64⇥128 binary weights (-1 or +1) values for the binary neural networks (BNNs). Each row of the bit cell array corresponding to a single neuron consists of a total of 128 cells, 64x cells for dot-product and 64x replicas cells for ADC reference. And 64x replicas cells consist of 32x cells for ADC reference and 32x cells for o↵set calibration. We used a row-by-row ADC for the quantized outputs of each neuron, which supports 1-7 bits of output for each neuron. The ADC uses the sweeping method using 32x duplicate bit cells, and the sweep cycle is set to 2N1 +1, where N is the number of output bits. The simulation is performed at room temperature (27C) using 32nm CNFET and 20nm FinFET technology via Synopsys Hspice, and all transistors in bitcells use the minimum size considering the area, power, and speed. The proposed SRAM-CIM has reduced power consumption for vector-matrix multiplication by 99.96% compared to the existing state-of-the-art SRAM-CIM. Moreover, because of the separated reading unit from an internal node of latch, there is no feedback from the read access circuit, which makes it read static noise margin (SNM) free. Furthermore, for the low power AI accelerator design, we propose a new AI accelerator design method that applies low power techniques such as bus specific clock gating (BSCG) and local explicit clock gating (LECG) at the register-transfer- level (RT-level). And evaluates them on the Xilinx ZCU-102 FPGA SoC hardware platform and 45nm technology for ASIC, respectively. It measures dynamic power using a commercial EDA tool, and chooses only a subset of FFs to be gated selectively based on their switching activities. We achieve up to a 53.21% power reduction in the ASIC implementation and saved 32.72% of the dynamic power dissipation in the FPGA implementation. This shows that our RTL low power schemes have a powerful possibility of dynamic power reduction when applied to the FPGA design flow and ASIC design flow for the implementation of the AI system.
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Title: Investigating The Impact of Tall Building Ordinances (TBOs) on the Evolution of Ultra-Tall Buildings Typology: Case Studies in Chicago and Dubai
Creator: Alkoud, Amjad
Date: 2023
Description: Zoning ordinances are instruments that tangibly and intangibly shape cities; control urban morphology, demography, and visual identity; and...
Show moreZoning ordinances are instruments that tangibly and intangibly shape cities; control urban morphology, demography, and visual identity; and determine the inhabitants' life quality, well-being, and comfort. Tall building ordinances (TBOs), in turn, control the vertical growth of cities and the development of tall buildings as distinctive actors in the built environment today. With the recent proliferation of developing Ultra-tall buildings in cities around the world, ordinances should offer flexibility, adaptability, and responsiveness to the dynamic nature of emerging needs and technological potentials.This dissertation investigates the emergence of Ultra-tall buildings as a new typology in major metropolises and the interaction between the building ordinances and the construction of Ultra-tall. The work presented in this dissertation implements two primary research methods: cross-sectional surveys and longitudinal studies, documenting supertall buildings completed in two major cities, Chicago and Dubai. The discussions and findings are supported by structured interviews with architects and engineers actively involved in designing and constructing Ultra-tall buildings. The cross-sectional survey comprises all supertall buildings (i.e., buildings above 1000 feet in height) completed as of 2022 in Chicago, the cradle of the "modern" high-rise with 318 towers of 100-plus meters and eight supertall towers of 300-plus meters; and Dubai, the new experimental land of supertall construction with 298 towers of 100-plus meters and 28 towers of 300-plus meters height. The longitudinal case studies provide additional information and knowledge about selected examples in Chicago and Dubai, derived from personal structured interviews conducted in both cities. Several additional survey cases from China, NYC, and London were investigated for their importance and uniqueness in supporting the research discussions and findings. This research aims to bridge the gap between the building ordinance literature and Ultra-tall building design practices on the one hand. On the other hand, it sheds light on the necessity to realize Ultra-tall buildings as a distinct typology entitled to its particular set of ordinances.The research findings are intended to help architects, engineers, policymakers, and planning authorities ensure a sustainable socioeconomic future and mitigate the negative impact of Ultra-tall constructions in major cities. This goal is assumed to be achieved by developing a set of recommendations, strategies, and universal criteria to implement a more flexible and responsive approach toward emerging human needs and technologies.
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Title: Quantifying Localization Safety for State-of-the-Art Mobile Robot Estimation Algorithms
Creator: Abdul Hafez, Osama Mutie Fahad
Date: 2023
Description: In mobile robotics, localization safety is quantified using covariance matrix or particle spread.However, such methods are insufficient for...
Show moreIn mobile robotics, localization safety is quantified using covariance matrix or particle spread.However, such methods are insufficient for mission or life-critical applications, like Autonomous Vehicles (AVs), because they only reflect nominal sensor noise without considering sensor measurement faults. Sensor faults are unknown deterministic errors that cannot be modeled using a zero mean Gaussian distribution. Ignoring sensor faults, in such applications, might result in large localization errors, which in turn deceives other reliant systems, like the controller, leading to catastrophic consequences, such as traffic accidents for AVs. Thus, other techniques need to be used to conservatively quantify pose safety.This thesis builds upon previous research in aviation safety, or what is referred to as \textit{integrity monitoring}, to quantify localization safety for mobile robots that use state-of-the-art state estimators (as localizers).Specifically, this thesis utilizes the localization \textit{integrity risk} metric, as a measure of localization safety, which is defined as the probability of the robot's pose estimate error to lie outside pre-determined acceptable limits while an alarm is not triggered. Unlike open-sky aviation applications, where Global Navigation Satellite Systems (GNSS) signals are available, mobile robots operate in GNSS-denied, or in the best case GNSS-degraded, environments, which demands utilizing more complex set of sensors to guarantee an acceptable level of localization safety. This thesis provides a conservative measure of localization safety by rigorously upper-bounding the integrity risk while accounting for both nominal lidar noise and unmodeled lidar measurement faults.The contributions of this thesis include the design and analysis of practical integrity monitoring and failure detection procedures for mobile robots utilizing map-based particle filtering, a recursive integrity monitoring method for mobile robots utilizing map-based fixed lag smoothing for both solution-separation and chi-squared as failure detectors, the synthesis of an integrity monitoring procedure for mobile robots utilizing Extended Kalman Filter-based Simultaneous Localization And Mapping (EKF-based SLAM), and a Model Predictive Control (MPC) framework that is capable of planning mobile robot's trajectory to follow a predefined robot path while maintaining a predefined minimum level of mobile robot localization safety. The proposed methodologies are validated using both simulation and experimental results conducted in real-world urban university campus environments.
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Title: Designs and Optimizations of Oblivious Data Access for Mitigating Access Pattern Leakage
Creator: Che, Yuezhi
Date: 2023
Description: In today’s data-driven world, data outsourcing has grown, increasing the importance of data security and privacy. Data encryption, while...
Show moreIn today’s data-driven world, data outsourcing has grown, increasing the importance of data security and privacy. Data encryption, while providing some protection, is insufficient against side-channel attacks such as access pattern leakage. This thesis focuses on designing and optimizing efficient oblivious access methods to enhance data security and privacy. Traditional solutions, like Oblivious RAM (ORAM), often impose significant overheads, limiting their market adoption. Our research proposes novel oblivious data access schemes tailored to specific applications, systems, and contexts. This approach enables us to identify critical vulnerabilities and performance bottlenecks, and balance performance, security, and other relevant parameters. In this thesis, I present four published works in Chapters 3 to 6, demonstrating the effectiveness of my proposed methods: (1) optimizing Ring ORAM for multi-channel memory systems, (2) introducing a multi-range supported ORAM for locality-aware applications, (3) proposing an oblivious data access solution for NVM hybrid memory systems, and (4) developing an oblivious access method for deep neural networks (DNNs), ensuring privacy without sacrificing performance. These contributions address unique challenges across application domains, enhancing data security and privacy in contemporary computing systems. This thesis provides a comprehensive investigation of targeted oblivious access methods, highlighting the benefits of the proposed designs, and contributing to more effective solutions for access pattern leakage mitigation, ultimately improving data security and privacy in contemporary computing systems.
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Title: Developing Adaptive and Predictive Modules for the Second Generation of Multivariable Insulin Delivery System for People with Type-1 Diabetes
Creator: Askari, Mohammad Reza
Date: 2023
Description: In this research, we are developing the second generation of multivariable automated insulin delivery system (mvAID) for people with Type 1...
Show moreIn this research, we are developing the second generation of multivariable automated insulin delivery system (mvAID) for people with Type 1 diabetes (T1D). AID system is improved by integrating missing data from sensors into the system, reconciling outliers in the data, and eliminating the effects of artifacts in signals from wearable devices. Behavioral patterns of individuals with T1D are captured by data-driven models. The model predictive control algorithm of the mvAID uses these patterns for making decisions and predicting glucose concentrations in the future more accurately. A pipeline algorithm is developed for removing noise and motion artifacts from wristband signals. Then, energy expenditure, physical activity, and acute psychological stress (APS) are estimated from wearable device signals to detect and quantify disturbances affecting the concentration of blood glucose concentration. Additionally, different modules were designed for predicting risky glycemic episodes and are used to build the second generation of the mvAID system. The techniques developed are tested with historical data sets from various clinical experiments and free-living data, and with simulations made by using our multivariable glucose, insulin and physiological variables simulator (mGIPsim).
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Title: Applications of Optimal Contract Theory in Brokerage
Creator: Alonso Alvarez, Guillermo
Date: 2023
Description: In this thesis we study optimal brokerage problems in different scenarios. The thesisis structured in two parts:...
Show moreIn this thesis we study optimal brokerage problems in different scenarios. The thesisis structured in two parts: In the first part of this thesis, corresponding to Chapter 2 and 3, we construct optimal brokerage contracts for multiple (heterogeneous) clients trading a single asset whose price follows the Almgren-Chriss model. The distinctive features of this work are as follows: (i) the reservation values of the clients are determined endogenously, and (ii) the broker is allowed to not offer a contract to some of the potential clients, thus choosing her portfolio of clients strategically. We find a computationally tractable characterization of the optimal portfolios of clients (up to a digital optimization problem, which can be solved efficiently if the number of potential clients is small) and conduct numerical experiments which illustrate how these portfolios, as well as the equilibrium profits of all market participants, depend on the price impact coefficients. In the second part of this thesis, corresponding to Chapter 4, we establish existence of a solution to the optimal contract problem in models where the state process is given by a multidimensional diffusion with linearly controlled drift. Then, under certain concavity assumptions, we show that the optimal contracts in the relaxed formulation also solve the associated strong optimal contract problem. The main advantages of this approach, relative to the existing methods, are due to the fact that it allows (i) to obtain the existence of an optimal contract (as a limit point of epsilon-optimal ones), and (ii) to include various additional constraints on the associated control problems (e.g., state constraints, difference in filtrations of the agent and of the principal, etc.). Finally, we apply our results to the problem of brokerage fees when the agent has access to a larger filtration.
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Title: Qualitative Investigation of Stigma Experiences of Individuals Living with Hoarding Disorder
Creator: Bates, Sage
Date: 2023
Description: Hoarding disorder (HD) is characterized by significant difficulty discarding items, resulting in an accumulation of clutter. HD is a public...
Show moreHoarding disorder (HD) is characterized by significant difficulty discarding items, resulting in an accumulation of clutter. HD is a public health concern and is associated with treatment ambivalence (e.g., refusal to initiate treatment, dropout, and limited treatment compliance). While low insight and motivation may account for some of the treatment ambivalence, it also could be due to a number of other factors related to how HD is being perceived by others, such as stigma. Yet, there is very little research on the relationship between stigma and hoarding, and what these studies have shown is that HD is judged negatively by the general population (i.e., public stigma) in a variety of ways. However, despite these initial findings, there are no in-depth studies examining stigma of HD from the perspective of those with lived experience. Further, previous research of stigma and HD utilized stigma measures that were significantly modified from their original intent to measure severe mental illness, and it is possible that general measures of stigma may not capture the specific features of HD or public perceptions of HD. The present study is a qualitative analysis to investigate stigma pertinent to HD.
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Title: Towards Utility-Driven Data Analytics with Differential Privacy
Creator: Wang, Han
Date: 2023
Description: The widespread use of personal devices and dedicated recording facilities has led to the generation of massive amounts of personal information...
Show moreThe widespread use of personal devices and dedicated recording facilities has led to the generation of massive amounts of personal information or data. Some of them are high-dimensional and unstructured data, such as video and location data. Analyzing these data can provide significant benefits in real-world scenarios, such as videos for monitoring and location data for traffic analysis. However, while providing benefits, these complicated data always raise serious privacy concerns since all of them involve personal information. To address privacy issues, existing privacy protection methods often fail to provide adequate utility in practical applications due to the complexity of high-dimensional and unstructured data. For example, most video sanitization techniques merely obscure the video by detecting and blurring sensitive regions, such as faces, vehicle plates, locations, and timestamps. Unfortunately, privacy breaches in blurred videos cannot be effectively contained, especially against unknown background knowledge. In this thesis, we propose three different differentially private frameworks to preserve the utility of video and location data (both are high-dimensional and unstructured data) while meeting the privacy requirements, under different well-known privacy settings. Specifically, to our best knowledge, wepropose the first differentially private video analytics platform (VideoDP) which flexibly supports different video queries or query-based analyze with a rigorous privacy guarantee. Given the input video, VideoDP randomly generates a utility-driven private video in which adding or removing any sensitive visual element (e.g., human, and object) does not significantly affect the output video. Then, different video analyses requested by untrusted video analysts can be flexibly performed over the sanitized video with differential privacy. Secondly, we define a novel privacy notion ϵ-Object Indistinguishability for all the predefined sensitive objects (e.g., humans, vehicles) in the video, and then propose a video sanitization technique VERRO that randomly generates utility-driven synthetic videos with indistinguishable objects. Therefore, all the objects can be well protected in the generated utility-driven synthetic videos which can be disclosed to any untrusted video recipient. Third, we propose the first strict local differential privacy (LDP) framework for location-based service (LBS) (“L-SRR”) to privately collect and analyze user locations or trajectories with ε-LDP guarantees. Specifically, we design a novel LDP mechanism “staircase randomized response” (SRR) and extend the empirical estimation to further boost the utility for a diverse set of LBS Apps (e.g., traffic density estimation, k nearest neighbors search, origin-destination analysis, and traffic-aware GPS navigation). Finally, we conduct experiments on real videos and location dataset, and the experimental results demonstrate all frameworks can have good performance.
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Title: Latent Price Model for Market Microstructure: Estimation and Simulation
Creator: Yin, Yuan
Date: 2023
Description: This thesis focuses on exploring and solving several problems based on partiallyobserved diffusion models. The thesis has two parts....
Show moreThis thesis focuses on exploring and solving several problems based on partiallyobserved diffusion models. The thesis has two parts. In the first part we present a tractable sufficient condition for the consistency of maximum likelihood estimators (MLEs) in partially observed diffusion models, stated in terms of stationary distributions of the associated test processes, under the assumption that the set of unknown parameter values is finite. We illustrate the tractability of this sufficient condition by verifying it in the context of a latent price model of market microstructure. Finally, we describe an algorithm for computing MLEs in partially observed diffusion models and test it on historical data to estimate the parameters of the latent price model. In the second part we provide a thorough analysis of the particle filtering algorithm for estimating the conditional distribution in partially observed diffusion models. Specifically, we focus on estimating the distribution of unobserved processes using observed data. The algorithm involves several steps and assumptions, which are described in detail. We also examine the convergence of the algorithm and identify the sufficient conditions under which it converges. Finally, we derive an explicit upper bound of the convergence rate of the algorithm, which depends on the set of parameters and the choice of time frequency. This bound provides a measure of the algorithm’s performance and can be used to optimize its parameters to achieve faster convergence.
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Title: Electric Machine Windings with Reduced Space Harmonic Content
Creator: Tang, Nanjun
Date: 2023
Description: The reduction of magnetomotive force (MMF) space harmonic content in electric machine windings can significantly improve the machine's...
Show moreThe reduction of magnetomotive force (MMF) space harmonic content in electric machine windings can significantly improve the machine's electromagnetic performance. Potential benefits include a reduction of torque ripple, a more sinusoidal back EMF, and reduced power losses. With the proposal of a uniform mathematical representation that applies to both distributed windings and fractional-slot concentrated windings (FSCWs), closed-form expressions can be derived for harmonic magnitudes, winding factors, etc. These expressions can then be used to formulate the MMF space harmonic suppression problem for windings, which looks for improved windings with certain harmonic orders reduced or even eliminated, by varying the slot distribution and coil turns. Different solution techniques are explored to gain additional insights about the solution space. The underlying mathematical relations between different harmonic orders are mathematically proved to establish the family phenomenon, which presents clear pictures of the higher order part of the harmonic spectrum and is the foundation for exact calculation of the total harmonic distortion (THD) of windings. The exact THD calculation further indicates how the minimal THD can be achieved for a winding. Windings can also be analyzed and designed from the view of subsets to incorporate distribution and excitation phase shift effects. With reduced or the minimal space harmonic content, new winding designs can help significantly improve the Pareto front when combined with motor geometry optimization. Design examples including a 12-slot 2-pole mixed-layer distributed winding, a 18-slot 2-pole mixed-layer distributed winding, and a four-layer 24-slot 22-pole FSCW with excitation phase shift are presented with finite element analysis (FEA) results to verify the performance improvements.
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Title: Polarization Induced by A Terahertz Electric Field in A Semiconductor Nanodimer in the Overlapping Regime
Creator: Wang, Zi
Date: 2023
Description: Boltzmann transport equation is a theoretical framework for the description of thermodynamics or charge reactions in a system not in...
Show moreBoltzmann transport equation is a theoretical framework for the description of thermodynamics or charge reactions in a system not in equilibrium, which can be applied to the analysis of the interactions of mobile charges with an electromagnetic wave. When the dimensions of the object are small compared to the wavelength, the induced dipole moment provides a means to characterize the collective response while providing insight to the nature of the charge-field interactions. Semiconductor nanoparticles exhibit surface plasmon resonance in the terahertz frequency range and are of current interest for the development of components and circuits in that part of the electromagnetic spectrum. By changing the plasmon frequencies of doped semiconductors through the change of carrier concentration, new opportunities arise for plasmonic manipulation in terahertz region leading to various promising applications. Despite the Drude model's long-term success and convenience in describing the electrical conductivity of metals in terms of dielectric functions, some aspects of polarization are not accounted for by bulk properties. By incorporating the transport equations of the charge carriers with Maxwell's equations, screening effects of charge carriers can be accounted for, enabling the internal field, space charge and induced dipole moment of a semiconductor nanoparticle to be studied.The computations performed for elementary dimer structures in overlapping cases revealed the internal field screening, while the complex dipole moments show dispersion and absorption effects. The numerical algorithms are implemented using the finite element method to investigate the surface plasmon resonance (SPR) induced on the semiconductor particles. Unique SPR modes evolution is observed as the thickness of the overlap region is varied. The characteristics can be interpreted by the migration of local space charge as the level of overlap is varied. This degree of freedom provided by a semiconductor nanodimer could be employed to control the local field near a simple cluster of nanoparticles, with potential for application in sensing and circuit components in the terahertz frequency range.
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