ASU Electronic Theses and Dissertations
This collection includes most of the ASU Theses and Dissertations from 2011 to present. ASU Theses and Dissertations are available in downloadable PDF format; however, a small percentage of items are under embargo. Information about the dissertations/theses includes degree information, committee members, an abstract, supporting data or media.
In addition to the electronic theses found in the ASU Digital Repository, ASU Theses and Dissertations can be found in the ASU Library Catalog.
Dissertations and Theses granted by Arizona State University are archived and made available through a joint effort of the ASU Graduate College and the ASU Libraries. For more information or questions about this collection contact or visit the Digital Repository ETD Library Guide or contact the ASU Graduate College at gradformat@asu.edu.
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- Creators: Shrivastava, Aviral
- Creators: Mobasher, Barzin
Description
Alkali-activated aluminosilicates, commonly known as "geopolymers", are being increasingly studied as a potential replacement for Portland cement. These binders use an alkaline activator, typically alkali silicates, alkali hydroxides or a combination of both along with a silica-and-alumina rich material, such as fly ash or slag, to form a final product with properties comparable to or better than those of ordinary Portland cement. The kinetics of alkali activation is highly dependent on the chemical composition of the binder material and the activator concentration. The influence of binder composition (slag, fly ash or both), different levels of alkalinity, expressed using the ratios of Na2O-to-binders (n) and activator SiO2-to-Na2O ratios (Ms), on the early age behavior in sodium silicate solution (waterglass) activated fly ash-slag blended systems is discussed in this thesis. Optimal binder composition and the n values are selected based on the setting times. Higher activator alkalinity (n value) is required when the amount of slag in the fly ash-slag blended mixtures is reduced. Isothermal calorimetry is performed to evaluate the early age hydration process and to understand the reaction kinetics of the alkali activated systems. The differences in the calorimetric signatures between waterglass activated slag and fly ash-slag blends facilitate an understanding of the impact of the binder composition on the reaction rates. Kinetic modeling is used to quantify the differences in reaction kinetics using the Exponential as well as the Knudsen method. The influence of temperature on the reaction kinetics of activated slag and fly ash-slag blends based on the hydration parameters are discussed. Very high compressive strengths can be obtained both at early ages as well as later ages (more than 70 MPa) with waterglass activated slag mortars. Compressive strength decreases with the increase in the fly ash content. A qualitative evidence of leaching is presented through the electrical conductivity changes in the saturating solution. The impact of leaching and the strength loss is found to be generally higher for the mixtures made using a higher activator Ms and a higher n value. Attenuated Total Reflectance-Fourier Transform Infrared Spectroscopy (ATR-FTIR) is used to obtain information about the reaction products.
ContributorsChithiraputhiran, Sundara Raman (Author) / Neithalath, Narayanan (Thesis advisor) / Rajan, Subramaniyam D (Committee member) / Mobasher, Barzin (Committee member) / Arizona State University (Publisher)
Created2012
Description
Pan Tilt Traffic Cameras (PTTC) are a vital component of traffic managementsystems for monitoring/surveillance. In a real world scenario, if a vehicle is in pursuit
of another vehicle or an accident has occurred at an intersection causing traffic
stoppages, accurate and venerable data from PTTC is necessary to quickly localize
the cars on a map for adept emergency response as more and more traffic systems are
getting automated using machine learning concepts. However, the position(orientation)
of the PTTC with respect to the environment is often unknown as most of them
lack Inertial Measurement Units or Encoders. Current State Of the Art systems 1.
Demand high performance compute and use carbon footprint heavy Deep Neural
Networks(DNN), 2. Are only applicable to scenarios with appropriate lane markings or
only roundabouts, 3. Demand complex mathematical computations to determine focal
length and optical center first before determining the pose. A compute light approach
"TIPANGLE" is presented in this work. The approach uses the concept of Siamese
Neural Networks(SNN) encompassing simple mathematical functions i.e., Euclidian
Distance and Contrastive Loss to achieve the objective. The effectiveness of the
approach is reckoned with a thorough comparison study with alternative approaches
and also by executing the approach on an embedded system i.e., Raspberry Pi 3.
ContributorsJagadeesha, Shreehari (Author) / Shrivastava, Aviral (Thesis advisor) / Gopalan, Nakul (Committee member) / Arora, Aman (Committee member) / Arizona State University (Publisher)
Created2023
Description
Deep metric learning has recently shown extremely promising results in the classical data domain, creating well-separated feature spaces. This idea was also adapted to quantum computers via Quantum Metric Learning (QMeL). QMeL consists of a 2 step process with a classical model to compress the data to fit into the limited number of qubits, then train a Parameterized Quantum Circuit (PQC) to create better separation in Hilbert Space. However, on Noisy Intermediate Scale Quantum (NISQ) devices, QMeL solutions result in high circuit width and depth, both of which limit scalability. The proposed Quantum Polar Metric Learning (QPMeL ), uses a classical model to learn the parameters of the polar form of a qubit. A shallow PQC with Ry and Rz gates is then utilized to create the state and a trainable layer of ZZ(θ)-gates to learn entanglement. The circuit also computes fidelity via a SWAP Test for the proposed Fidelity Triplet Loss function, used to train both classical and quantum components. When compared to QMeL approaches, QPMeL achieves 3X better multi-class separation, while using only 1/2 the number of gates and depth. QPMeL is shown to outperform classical networks with similar configurations, presentinga promising avenue for future research on fully classical models with quantum loss functions.
ContributorsSharma, Vinayak (Author) / Shrivastava, Aviral (Thesis advisor) / Jiang, Zilin (Committee member) / Kambhampati, Subbarao (Committee member) / Arizona State University (Publisher)
Created2024
Description
Research in building agents by employing Large Language Models (LLMs) for computer control is expanding, aiming to create agents that can efficiently automate complex or repetitive computational tasks. Prior works showcased the potential of Large Language Models (LLMs) with in-context learning (ICL). However, they suffered from limited context length and poor generalization of the underlying models, which led to poor performance in long-horizon tasks, handling multiple applications and working across multiple domains. While initial work focused on extending the coding capabilities of LLMs to work with APIs to accomplish tasks, a new body of work focused on Graphical User Interface (GUI) manipulation has shown strong success in web and mobile application automation. In this work, I introduce LUCI: Large Language Model-assisted User Control Interface, a hierarchical, modular, and efficient framework to extend the capabilities of LLMs to automate GUIs. LUCI utilizes the reasoning capabilities of LLMs to decompose tasks into sub-tasks and recursively solve them. A key innovation is the application-centric approach which creates sub-tasks by first selecting the applications needed to solve the prompt. The GUI application is decomposed into a novel compressed Information-Action-Field (IAF) representation based on the underlying syntax tree. Furthermore, LUCI follows a modular structure allowing it to be extended to new platforms without any additional training as the underlying reasoning works on my IAF representations. These innovations alongside the `ensemble of LLMs' structure allow LUCI to outperform previous supervised learning (SL), reinforcement learning (RL), and LLM approaches on Miniwob++, overcoming challenges such as limited context length, exemplar memory requirements, and human intervention for task adaptability. LUCI shows a 20% improvement over the state-of-the-art (SOTA) in GUI automation on the Mind2Web benchmark. When tested in a realistic setting with over 22 commonly used applications, LUCI achieves an 80% success rate in undertaking tasks that use a subset of these applications. I also note an over 70% success rate on unseen applications, which is a less than 5% drop as compared to the fine-tuned applications.
ContributorsLAGUDU, GUNA SEKHAR SAI HARSHA (Author) / Shrivastava, Aviral (Thesis advisor) / Ramapuram Matavalam, Amarsagar Reddy (Committee member) / Chhabria, Vidya (Committee member) / Arizona State University (Publisher)
Created2024