Open Access. Powered by Scholars. Published by Universities.®

Physical Sciences and Mathematics Commons

Open Access. Powered by Scholars. Published by Universities.®

William & Mary

2020

Discipline
Keyword
Publication
Publication Type
File Type

Articles 121 - 127 of 127

Full-Text Articles in Physical Sciences and Mathematics

A First-Principles Study Of The Nature Of The Insulating Gap In Vo2, Christopher Hendriks Jan 2020

A First-Principles Study Of The Nature Of The Insulating Gap In Vo2, Christopher Hendriks

Dissertations, Theses, and Masters Projects

Upon cooling past a critical temperature Tc = 340 K Vanadium dioxide (VO2) exhibits a metal-insulator transition (MIT) from a metallic rutile R to an insulating monoclinic M1 phase. Other insulating phases, a monoclinic M2 and triclinic T, have been identifed and are accessible via strain or doping. Despite decades of research, the nature of the VO2 MIT is still not fully understood. In this work we present ab-initio hybrid density functional theory (DFT) calculations on the insulating phases, compare the results to experimental measurements and discuss their implications on our understanding of the VO2 MIT. Recent measurements on M1 …


Deep Learning In Software Engineering, Cody Watson Jan 2020

Deep Learning In Software Engineering, Cody Watson

Dissertations, Theses, and Masters Projects

Software evolves and therefore requires an evolving field of Software Engineering. The evolution of software can be seen on an individual project level through the software life cycle, as well as on a collective level, as we study the trends and uses of software in the real world. As the needs and requirements of users change, so must software evolve to reflect those changes. This cycle is never ending and has led to continuous and rapid development of software projects. More importantly, it has put a great responsibility on software engineers, causing them to adopt practices and tools that allow …


Competing And Cooperating Orders In The Three-Band Hubbard Model: A Comprehensive Quantum Monte Carlo And Generalized Hartree-Fock Study, Adam Chiciak Jan 2020

Competing And Cooperating Orders In The Three-Band Hubbard Model: A Comprehensive Quantum Monte Carlo And Generalized Hartree-Fock Study, Adam Chiciak

Dissertations, Theses, and Masters Projects

Significant progress has been made in studying strongly correlated electronic systems with major focus on understanding high-temperature superconductivity. At the center of these studies are the so-called cuprates, which are characterized by a quasi-2D Copper-Oxide plane in which superconductivity is believed to arise. From the theoretical point of view, the complex electronic structure of these materials makes a fully ab initio many-body computation a formidable task, so we are forced to focus on minimal models that can reproduce the physics, the most well known of which is known as the Hubbard Model, which relies on the Zhang-Rice singet notion to …


Design And Analysis Of Memory Management Techniques For Next-Generation Gpus, Haonan Wang Jan 2020

Design And Analysis Of Memory Management Techniques For Next-Generation Gpus, Haonan Wang

Dissertations, Theses, and Masters Projects

Graphics Processing Unit (GPU)-based architectures have become the default accelerator choice for a large number of data-parallel applications because they are able to provide high compute throughput at a competitive power budget. Unlike CPUs which typically have limited multi-threading capability, GPUs execute large numbers of threads concurrently to achieve high thread-level parallelism (TLP). While the computation of each thread requires its corresponding data to be loaded from or stored to the memory, the key to supporting the high TLP of GPUs lies in the high bandwidth provided by the GPU memory system. However, with the continuous scaling of GPUs, the …


Study Of Scalar Extensions For Physics Beyond The Standard Model, Marco Antonio Merchand Medina Jan 2020

Study Of Scalar Extensions For Physics Beyond The Standard Model, Marco Antonio Merchand Medina

Dissertations, Theses, and Masters Projects

In this thesis we investigate the phenomenology of beyond the Standard Model scenarios with extra scalar fields. A review and motivation of extended electroweak symmetry breaking is presented. Then we address observational evidence of new physics such as possible lepton flavor violating processes and the relic abundance of dark matter by implementing models with three Higgs doublets. The complementarity between theoretical restrictions and experimental bounds on some of the predicted signals is leveraged to sharpen the allowed parameter space. After that we study embeddings of two-Higgs doublets into the Randall-Sundrum model with emphasis on the scalar fluctuations of the metric …


Development Of Quantum Information Tools Based On Multi-Photon Raman Processes In Rb Vapor, Nikunjkumar Prajapati Jan 2020

Development Of Quantum Information Tools Based On Multi-Photon Raman Processes In Rb Vapor, Nikunjkumar Prajapati

Dissertations, Theses, and Masters Projects

Multi-photon nonlinear processes in atoms have served as important tools for quantum metrology, quantum communications, and quantum sensing. In this thesis, we experimentally address the interplay of various multi-photon Raman processes in hot Rb vapor, with the four-wave mixing (FWM) process being a central theme. FWM is the nonlinear response of a medium to a strong optical pump field inelastically scattering off atomic resonances and resulting in the generation of additional photons in different modes. FWM is a detrimental, but inherent part of electromagnetically induced transparency (EIT) and Raman based quantum memories. However, we were able to weaken the four-photon …


Motion Sensors-Based Human Behavior Recognition And Analysis, Hongyang Zhao Jan 2020

Motion Sensors-Based Human Behavior Recognition And Analysis, Hongyang Zhao

Dissertations, Theses, and Masters Projects

Human behavior recognition and analysis have been considered as a core technology that can facilitate a variety of applications. However, accurate detection and recognition of human behavior is still a big challenge that attracts a lot of research efforts. Among all the research works, motion sensors-based human behavior recognition is promising as it is low cost, low power, and easy to carry. In this dissertation, we use motion sensors to study human behaviors. First, we present Ultigesture (UG) wristband, a hardware platform for detecting and analyzing human behavior. The hardware platform integrates an accelerometer, gyroscope, and compass sensor, providing a …