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Full-Text Articles in Engineering
Theoretical Analysis Of Charge Conduction And Rectification In Self-Assembled-Monolayers In Molecular Junctions, Francis Adoah
Theoretical Analysis Of Charge Conduction And Rectification In Self-Assembled-Monolayers In Molecular Junctions, Francis Adoah
Electronic Theses and Dissertations, 2020-
As electrical devices shrink to the atomic scale, it is expected that Moore's law will soon be obsolete for semiconductor devices. In 1974, Avriam and Ratner predicted that organic devices could replace semiconductor technology, leading to extensive research on molecular-based organic devices. This dissertation delves into the theoretical frameworks used to examine the transport in molecular junctions and aims to enhance our comprehension of charge transport and conduction properties. The studies presented in this thesis illustrates that a molecule's alteration by just a single atom can change it from an insulator to a conductor, and also that, by fine-tuning the …
Distributed Optimization With Limited Communication In Networks With Adversaries, Iyanuoluwa Emiola
Distributed Optimization With Limited Communication In Networks With Adversaries, Iyanuoluwa Emiola
Electronic Theses and Dissertations, 2020-
We all hope for the best but sometimes, one must plan for ways of dealing with the worst-case scenarios, especially in a network with adversaries. This dissertation illustrates a detailed description of distributed optimization algorithms over a network of agents, in which some agents are adversarial. The model considered is such that adversarial agents act to subvert the objective of the network. The algorithms presented in this dissertation are solved via gradient-based distributed optimization algorithm and the effects of the adversarial agents on the convergence of the algorithm to the optimal solution are characterized. The analyses presented establish conditions under …
Towards Explainable Ai Using Attribution Methods And Image Segmentation, Garrett J. Rocks
Towards Explainable Ai Using Attribution Methods And Image Segmentation, Garrett J. Rocks
Honors Undergraduate Theses
With artificial intelligence (AI) becoming ubiquitous in a broad range of application domains, the opacity of deep learning models remains an obstacle to adaptation within safety-critical systems. Explainable AI (XAI) aims to build trust in AI systems by revealing important inner mechanisms of what has been treated as a black box by human users. This thesis specifically aims to improve the transparency and trustworthiness of deep learning algorithms by combining attribution methods with image segmentation methods. This thesis has the potential to improve the trust and acceptance of AI systems, leading to more responsible and ethical AI applications. An exploratory …
Examining Direct Load Control Within Demand Response Programs, Maria Bonina Zimath
Examining Direct Load Control Within Demand Response Programs, Maria Bonina Zimath
Honors Undergraduate Theses
The power system is a complex entity with unique plant designs, control systems, and market strategies. For many years, engineers have developed advanced technology to keep the grid efficient and balanced. With the rise of renewable sources, some new technology and programs must be developed to keep the quality of the power system. Unlike traditional power plants, renewable energy is highly dependent on environmental factors, such as sunlight and wind, meaning the generation depends on an unpredictable source of fuel. As the grid moves to more sustainable sources, the power market faces a growing challenge of less control over the …
Process Optimization And Characterization Of P-Type Copper Indium Oxide And Copper Chromium Oxide Transparent Conducting Thin Films And Its Applications, Fnu Sreeram Sundaresh
Process Optimization And Characterization Of P-Type Copper Indium Oxide And Copper Chromium Oxide Transparent Conducting Thin Films And Its Applications, Fnu Sreeram Sundaresh
Electronic Theses and Dissertations, 2020-
Transparent conducting oxides (TCO) are a unique class of compounds that combine the properties of being optically transparent but at the same time are electrically conductive. TCOs are used in a variety of applications such as transparent contacts for solar cells, electrochromic windows, low-e windows, optoelectronic devices, light-emitting diodes, optical displays, UV sensors, defrosting windows, etc. By controlling doping and by adjusting the donor/acceptor levels, the conductivity of TCOs can be tuned from insulating via semiconducting to conducting. Various properties of TCOs such as optical transparency, bandgap, and electrical conductivity can be controlled using the aforementioned process. This concept paved …
Ocean Vector Wind Measurement Potential From The Global Precipitation Measurement Mission Using A Combined Active And Passive Algorithm, Alamgir Hossan
Ocean Vector Wind Measurement Potential From The Global Precipitation Measurement Mission Using A Combined Active And Passive Algorithm, Alamgir Hossan
Electronic Theses and Dissertations, 2020-
Ocean surface vector wind (OVW) is an essential parameter for understanding the physics and dynamics of the ocean-atmosphere system, thereby improving weather forecasting and climate studies. Satellite scatterometers, synthetic aperture radars, and polarimetric microwave radiometers have provided almost global coverage of ocean surface vector wind for the last four decades. Nonetheless, a consistent and uninterrupted long-time data record with the capability of resolving sub-diurnal variability has remained a critical challenge over the years. The Global Precipitation Measurement Mission (GPM) is a satellite mission designed to provide space-based precipitation information on a global scale with complete diurnal sampling. This dissertation presents …
Adversarial Attacks, Coarse Robustness, And Dataless Neural Networks: Novel Techniques For Improved Classification And Combinatorial Optimization, Ismail Alkhouri
Adversarial Attacks, Coarse Robustness, And Dataless Neural Networks: Novel Techniques For Improved Classification And Combinatorial Optimization, Ismail Alkhouri
Electronic Theses and Dissertations, 2020-
Neural networks (NN) have become a central component in most machine learning systems. However, studies have shown that these models are not robust against adversarial attacks. As such, in this dissertation, we explore four directions. In the first direction, we investigate adversarial attacks on two hierarchical classification (HC) models: the Flat HC (FHC), and the Top-Down HC (TDHC). In particular, we formulate attacks against these models by using convex programming. Through experimental results, it is shown that FHCs are more robust than TDHCs. Second, we formalize a new notion of coarse robustness that is defined with respect to a specified …
Coalition Formation And Beamsteering Optimization For Directional Software-Defined Radios, Sayanta Seth
Coalition Formation And Beamsteering Optimization For Directional Software-Defined Radios, Sayanta Seth
Graduate Thesis and Dissertation 2023-2024
Dynamic Spectrum Access (DSA), also known as Dynamic Spectrum Management, is the method of utilizing a set of spectrum techniques in real time to provide the ability to share wireless channels between Primary (or licensed) users (PUs) and Secondary (or unlicensed) users (SUs). The system is so designed that under normal circumstances, the PUs always get priority, but DSA enables the SUs to use the licensed bands as long as they do not create any interference on the PUs. Hence, the goal of utilizing the spectrum more efficiently can be achieved. Though DSA has been researched extensively as a new …
Structural Transformations In Photo-Thermo-Refractive Glass For Hologram Recording, Roberto Alejandro Alvarez Aguirre
Structural Transformations In Photo-Thermo-Refractive Glass For Hologram Recording, Roberto Alejandro Alvarez Aguirre
Electronic Theses and Dissertations, 2020-
This dissertation focuses on the structural transformations in photo-thermo-refractive (PTR) glass that enable recording phase holograms for efficient transformation of optical beams and high resolution spectroscopy. PTR glass is a multicomponent silicate matrix doped with Ce, Ag, Sn and Sb. It is a holographic phase medium with the ability of permanent refractive index change after UV exposure and thermal development above 500°C due to the precipitation of a NaF crystalline phase. Electronic processes are studied by analyzing the structure of absorption and luminescence bands of PTR glass matrix and its dopants. We analyze the structural transformations in PTR glass from …
Active Photonic Integrated Devices And Circuits On Thin-Film Lithium Niobate Platform, Ehsan Ordouie
Active Photonic Integrated Devices And Circuits On Thin-Film Lithium Niobate Platform, Ehsan Ordouie
Electronic Theses and Dissertations, 2020-
This thesis delves into innovative active photonic integrated devices and circuits on the thin-film lithium niobate (TFLN) platform, focusing on their applications and potential future advancements. We introduce a new family of electrooptic modulators (EOMs), the Four-Phase Electrooptic Modulators (FEOMs), which are fabricated using the TFLN platform. These devices effectively mitigate bandwidth and dynamic-range constraints in optical communication systems by reducing dispersion penalties and common-mode noises. Their functionality is demonstrated in a photonic time-stretch system. A dual-polarization variant further exemplifies the mitigation of both dispersion penalties and common-mode noises in long-haul communication links, marking significant strides towards the practical implementation …
High-Efficieny Ultrafast Mid-Infrared Source For Strong Field Science, Fangjie Zhou
High-Efficieny Ultrafast Mid-Infrared Source For Strong Field Science, Fangjie Zhou
Electronic Theses and Dissertations, 2020-
The potential of high-energy sources within the mid-infrared region (3-8 μm) has garnered significant attention for diverse research and industrial applications. Millijoule pulses extending beyond 3 μm can facilitate the production of x-rays with photon energies in the keV range through high harmonic generation (HHG). These high-energy x-ray pulses enable the characterization of electron dynamics within molecules and condensed matter materials. Additionally, the atmospheric transmission window between 3-5 μm allows lasers within this spectral range to deliver energy efficiently to distant targets via optical filaments without divergence, highlighting promising prospects for defense applications. In contrast to laser amplifiers, which are …