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Physical Sciences and Mathematics Commons

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William & Mary

2019

Theses/Dissertations

Computer Sciences

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Full-Text Articles in Physical Sciences and Mathematics

On Enhancing Security Of Password-Based Authentication, Yue Li Jan 2019

On Enhancing Security Of Password-Based Authentication, Yue Li

Dissertations, Theses, and Masters Projects

Password has been the dominant authentication scheme for more than 30 years, and it will not be easily replaced in the foreseeable future. However, password authentication has long been plagued by the dilemma between security and usability, mainly due to human memory limitations. For example, a user often chooses an easy-to-guess (weak) password since it is easier to remember. The ever increasing number of online accounts per user even exacerbates this problem. In this dissertation, we present four research projects that focus on the security of password authentication and its ecosystem. First, we observe that personal information plays a very …


Improving Wifi Sensing And Networking With Channel State Information, Yongsen Ma Jan 2019

Improving Wifi Sensing And Networking With Channel State Information, Yongsen Ma

Dissertations, Theses, and Masters Projects

In recent years, WiFi has a very rapid growth due to its high throughput, high efficiency, and low costs. Multiple-Input Multiple-Output (MIMO) and Orthogonal Frequency-Division Multiplexing (OFDM) are two key technologies for providing high throughput and efficiency for WiFi systems. MIMO-OFDM provides Channel State Information (CSI) which represents the amplitude attenuation and phase shift of each transmit-receiver antenna pair of each carrier frequency. CSI helps WiFi achieve high throughput to meet the growing demands of wireless data traffic. CSI captures how wireless signals travel through the surrounding environment, so it can also be used for wireless sensing purposes. This dissertation …


Gpgpu Reliability Analysis: From Applications To Large Scale Systems, Bin Nie Jan 2019

Gpgpu Reliability Analysis: From Applications To Large Scale Systems, Bin Nie

Dissertations, Theses, and Masters Projects

Over the past decade, GPUs have become an integral part of mainstream high-performance computing (HPC) facilities. Since applications running on HPC systems are usually long-running, any error or failure could result in significant loss in scientific productivity and system resources. Even worse, since HPC systems face severe resilience challenges as progressing towards exascale computing, it is imperative to develop a better understanding of the reliability of GPUs. This dissertation fills this gap by providing an understanding of the effects of soft errors on the entire system and on specific applications. To understand system-level reliability, a large-scale study on GPU soft …


Learning Code Transformations Via Neural Machine Translation, Michele Tufano Jan 2019

Learning Code Transformations Via Neural Machine Translation, Michele Tufano

Dissertations, Theses, and Masters Projects

Source code evolves – inevitably – to remain useful, secure, correct, readable, and efficient. Developers perform software evolution and maintenance activities by transforming existing source code via corrective, adaptive, perfective, and preventive changes. These code changes are usually managed and stored by a variety of tools and infrastructures such as version control, issue trackers, and code review systems. Software Evolution and Maintenance researchers have been mining these code archives in order to distill useful insights on the nature of such developers’ activities. One of the long-lasting goal of Software Engineering research is to better support and automate different types of …


Research On Efficiency And Security For Emerging Distributed Applications, Zijiang Hao Jan 2019

Research On Efficiency And Security For Emerging Distributed Applications, Zijiang Hao

Dissertations, Theses, and Masters Projects

Distributed computing has never stopped its advancement since the early years of computer systems. In recent years, edge computing has emerged as an extension of cloud computing. The main idea of edge computing is to provide hardware resources in proximity to the end devices, thereby offering low network latency and high network bandwidth. However, as an emerging distributed computing paradigm, edge computing currently lacks effective system support. To this end, this dissertation studies the ways of building system support for edge computing. We first study how to support the existing, non-edge-computing applications in edge computing environments. This research leads to …