Open Access. Powered by Scholars. Published by Universities.®
Physical Sciences and Mathematics Commons™
Open Access. Powered by Scholars. Published by Universities.®
Articles 31 - 60 of 219
Full-Text Articles in Physical Sciences and Mathematics
Revisiting Isolation For System Security And Efficiency In The Era Of Internet Of Things, Lele Ma
Revisiting Isolation For System Security And Efficiency In The Era Of Internet Of Things, Lele Ma
Dissertations, Theses, and Masters Projects
Isolation is a fundamental paradigm for secure and efficient resource sharing on a computer system. However, isolation mechanisms in traditional cloud computing platforms are heavy-weight or just not feasible to be applied onto the computing environment for Internet of Things(IoT). Most IoT devices have limited resources and their servers are less powerful than cloud servers but are widely distributed over the edge of the Internet. Revisions to the traditional isolation mechanisms are needed in order to improve the system security and efficiency in these computing environments. The first project explores container-based isolation for the emerging edge computing platforms. We show …
High-Dimensional Machine Learning Models In Fintech, Qiong Wu
High-Dimensional Machine Learning Models In Fintech, Qiong Wu
Dissertations, Theses, and Masters Projects
This thesis develops several forecasting models for simultaneously predicting the prices of d assets traded in financial markets, a most fundamental problem in the emerging area of ``FinTech''. The models are optimized to address three critical challenges, C1. High-dimensional interactions between assets. Assets could interact (e.g., Amazon's disclosure of its revenue change in cloud services could indicate that revenues also could change in other cloud providers). The number of possible interactions is quadratic in d, and is often much larger than the number of observations. C2. Non-linearity of the hypothesis class. Linear models are usually insufficient to characterize the relationship …
Wearable Technology For Healthcare And Athletic Performance, Amanda Annette Watson
Wearable Technology For Healthcare And Athletic Performance, Amanda Annette Watson
Dissertations, Theses, and Masters Projects
Wearable technology research has led to advancements in healthcare and athletic performance. Devices range from one size fits all fitness trackers to custom fitted devices with tailored algorithms. Because these devices are comfortable, discrete, and pervasive in everyday life, custom solutions can be created to fit an individual's specific needs. In this dissertation, we design wearable sensors, develop features and algorithms, and create intelligent feedback systems that promote the advancement of healthcare and athletic performance. First, we present Magneto: a body mounted electromagnet-based sensing system for joint motion analysis. Joint motion analysis facilitates research into injury prevention, rehabilitation, and activity …
Hardware-Assisted Security Mechanisms On Arm-Based Multi-Core Processors, Shengye Wan
Hardware-Assisted Security Mechanisms On Arm-Based Multi-Core Processors, Shengye Wan
Dissertations, Theses, and Masters Projects
During the last decade, Trusted Execution Environment (TEE) provided by ARM TrustZone had become one of the most popular techniques to build security on mobile devices. On a TrustZone-enabled system, the software can execute in either Secure World (trusted) and Normal World (untrusted). Meanwhile, along with the expeditious development of TrustZone technology, the security of TEE is also challenged by dealing with more and more on-board hardware and in-TEE applications. In this dissertation, we explicitly study the security of ARM TrustZone technology with the latest ARM architecture in three aspects. First, we study the security of the TrustZone-assisted asynchronous introspection. …
Design And Analysis Of Memory Management Techniques For Next-Generation Gpus, Haonan Wang
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 …
Dietary Monitoring Through Sensing Mastication Dynamics, Shuangquan Wang
Dietary Monitoring Through Sensing Mastication Dynamics, Shuangquan Wang
Dissertations, Theses, and Masters Projects
Unhealthy dietary habits (such as eating disorders, eating too fast, excessive energy intake, and chewing side preference) are major causes of some chronic diseases, including obesity, heart disease, digestive system disease, and diabetes. Dietary monitoring is necessary and important for patients to change their unhealthy diet and eating habits. However, the existing monitoring methods are either intrusive or not accurate enough. In this dissertation, we present our efforts to use wearable motion sensors to sense mastication dynamics for continuous dietary monitoring. First, we study how to detect a subject's eating activity and count the number of chews. We observe that …
On Cross-Series Machine Learning Models, Xiaodan Zhu
On Cross-Series Machine Learning Models, Xiaodan Zhu
Dissertations, Theses, and Masters Projects
Sparse high dimensional time series are common in industry, such as in supply chain demand and retail sales. Accurate and reliable forecasting of high dimensional time series is essential for supply chain planning and business management. In practical applications, sparse high dimensional time series prediction faces three challenges: (1) simple models cannot capture complex patterns, (2) insufficient data prevents us from pursuing more advanced models, and (3) time series in the same dataset may have widely different properties. These challenges prevent the currently prevalent models and theoretically successful advanced models (e.g., neural networks) from working in actual use. We focus …
Motion Sensors-Based Human Behavior Recognition And Analysis, Hongyang Zhao
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 …
Understanding Performance Inefficiencies In Native And Managed Languages, Pengfei Su
Understanding Performance Inefficiencies In Native And Managed Languages, Pengfei Su
Dissertations, Theses, and Masters Projects
Production software packages have become increasingly complex with millions of lines of code, sophisticated control and data flow, and references to a hierarchy of external libraries. This complexity often introduces performance inefficiencies across software stacks, making it practically impossible for users to pinpoint them manually. Performance profiling tools (a.k.a. profilers) abound in the tools community to aid software developers in understanding program behavior. Classical profiling techniques focus on identifying hotspots. The hotspot analysis is indispensable; however, it can hardly diagnose whether a resource is being used in a productive manner that contributes to the overall efficiency of a program. Consequently, …
Exploring Heterogeneous Architectures With Tools And Applications, Du Shen
Exploring Heterogeneous Architectures With Tools And Applications, Du Shen
Dissertations, Theses, and Masters Projects
Heterogeneous architectures have become popular due to programming flexibility and energy efficiency. Heterogeneous architectures include GPU accelerators, and memory subsystems consisting fast and slow components. Achieving high performance for programs running on heterogeneous architectures requires sophisticated tools and applications. They either lack hardware support for fast memory component, or provide complex programming model, which puts extra burdens on compilers and programmers. However, existing tools either rely on simulators or lack support across different GPU architectures, runtime or driver versions. Thus, they only provide insufficient insights. In the first project, we develop DataPlacer, a profiling tool to provide guidance for data …
Deep Learning In Software Engineering, Cody Watson
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 …
Single Image Direct-Global Illumination Separation, Zhaoliang Duan
Single Image Direct-Global Illumination Separation, Zhaoliang Duan
Dissertations, Theses, and Masters Projects
Global light transport, including diffuse interreflections, caustic, refractions and subsurface scattering, is important to achieve photorealistic rendering. However rendering these phenomena is very time-consuming. Furthermore, many inverse rendering methods’ accuracy in computer graphics and computer vision is adversely affected by the presence of global light transport. Therefore, separating direct-global light transport components is necessary to help in designing new rendering methods and in improving the accuracy of many image inverse methods. Prior work on separating direct and global light transport from photographs either requires expensive hardware, requires multiple photographs of the scene, or fails to accurately recover high frequency details. …
Pinpointing Software Inefficiencies With Profiling, Shasha Wen
Pinpointing Software Inefficiencies With Profiling, Shasha Wen
Dissertations, Theses, and Masters Projects
Complex codebases with several layers of abstractions have abundant inefficiencies that affect the performance. These inefficiencies arise due to various causes such as developers' inattention to performance, inappropriate choice of algorithms and inefficient code generation among others. To eliminate the redundancies, lots of work has been done during the compiling phase. However, not all redundancies can be easily detected or eliminated with compiler optimization passes due to aliasing, limited optimization scopes, and insensitivity to input and execution contexts act as severe deterrents to static program analysis. There are also profiling tools which can reveal how resources are used. However, they …
Research On Efficiency And Security For Emerging Distributed Applications, Zijiang Hao
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 …
On Enhancing Security Of Password-Based Authentication, Yue Li
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 …
Gpgpu Reliability Analysis: From Applications To Large Scale Systems, Bin Nie
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
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 …
Improving Wifi Sensing And Networking With Channel State Information, Yongsen Ma
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 …
Exploring New Paradigms For Mobile Edge Computing, Yutao Tang
Exploring New Paradigms For Mobile Edge Computing, Yutao Tang
Dissertations, Theses, and Masters Projects
Edge computing has been rapidly growing in recent years to meet the surging demands from mobile apps and Internet of Things (IoT). Similar to the Cloud, edge computing provides computation, storage, data, and application services to the end-users. However, edge computing is usually deployed at the edge of the network, which can provide low-latency and high-bandwidth services for end devices. So far, edge computing is still not widely adopted. One significant challenge is that the edge computing environment is usually heterogeneous, involving various operating systems and platforms, which complicates app development and maintenance. in this dissertation, we explore to combine …
Quantifying And Explaining Causal Effects Of World Bank Aid Projects, Jianing Simulation Zhao
Quantifying And Explaining Causal Effects Of World Bank Aid Projects, Jianing Simulation Zhao
Dissertations, Theses, and Masters Projects
In recent years, machine learning methods have enabled us to predict with good precision using large training data, such as deep learning. However, for many problems, we care more about causality than prediction. For example, instead of knowing that smoking is statistically associated with lung cancer, we are more interested in knowing that smoking is the cause of lung cancer. With causality, we can understand how the world progresses and how impacts are made on an outcome by influencing the cause. This thesis explores how to quantify the causal effects of a treatment on an observable outcome in the presence …
Investigating Emerging Security Threats In Clouds And Data Centers, Xing Gao
Investigating Emerging Security Threats In Clouds And Data Centers, Xing Gao
Dissertations, Theses, and Masters Projects
Data centers have been growing rapidly in recent years to meet the surging demand of cloud services. However, the expanding scale of a data center also brings new security threats. This dissertation studies emerging security issues in clouds and data centers from different aspects, including low-level cooling infrastructures and different virtualization techniques such as container and virtual machine (VM). We first unveil a new vulnerability called reduced cooling redundancy that might be exploited to launch thermal attacks, resulting in severely worsened thermal conditions in a data center. Such a vulnerability is caused by the wide adoption of aggressive cooling energy …
Usability, Efficiency And Security Of Personal Computing Technologies, Nancy Carter
Usability, Efficiency And Security Of Personal Computing Technologies, Nancy Carter
Dissertations, Theses, and Masters Projects
New personal computing technologies such as smartphones and personal fitness trackers are widely integrated into user lifestyles. Users possess a wide range of skills, attributes and backgrounds. It is important to understand user technology practices to ensure that new designs are usable and productive. Conversely, it is important to leverage our understanding of user characteristics to optimize new technology efficiency and effectiveness. Our work initially focused on studying older users, and personal fitness tracker users. We applied the insights from these investigations to develop new techniques improving user security protections, computational efficiency, and also enhancing the user experience. We offer …
Understanding And Enriching Randomness Within Resource-Constrained Devices, Kyle Wallace
Understanding And Enriching Randomness Within Resource-Constrained Devices, Kyle Wallace
Dissertations, Theses, and Masters Projects
Random Number Generators (RNG) find use throughout all applications of computing, from high level statistical modeling all the way down to essential security primitives. A significant amount of prior work has investigated this space, as a poorly performing generator can have significant impacts on algorithms that rely on it. However, recent explosive growth of the Internet of Things (IoT) has brought forth a class of devices for which common RNG algorithms may not provide an optimal solution. Furthermore, new hardware creates opportunities that have not yet been explored with these devices. in this Dissertation, we present research fostering deeper understanding …
On Improving (Non)Functional Testing, Qi Luo
On Improving (Non)Functional Testing, Qi Luo
Dissertations, Theses, and Masters Projects
Software testing is commonly classified into two categories, nonfunctional testing and functional testing. The goal of nonfunctional testing is to test nonfunctional requirements, such as performance and reliability. Performance testing is one of the most important types of nonfunctional testing, one goal of which is to detect the phenomena that an Application Under Testing (AUT) exhibits unexpectedly worse performance (e.g., lower throughput) with some input data. During performance testing, a critical challenge is to understand the AUT’s behaviors with large numbers of combinations of input data and find the particular subset of inputs leading to performance bottlenecks. However, enumerating those …
Enhancing Usability, Security, And Performance In Mobile Computing, Shanhe Yi
Enhancing Usability, Security, And Performance In Mobile Computing, Shanhe Yi
Dissertations, Theses, and Masters Projects
We have witnessed the prevalence of smart devices in every aspect of human life. However, the ever-growing smart devices present significant challenges in terms of usability, security, and performance. First, we need to design new interfaces to improve the device usability which has been neglected during the rapid shift from hand-held mobile devices to wearables. Second, we need to protect smart devices with abundant private data against unauthorized users. Last, new applications with compute-intensive tasks demand the integration of emerging mobile backend infrastructure. This dissertation focuses on addressing these challenges. First, we present GlassGesture, a system that improves the usability …
Assisting Software Developers With License Compliance, Christopher Vendome
Assisting Software Developers With License Compliance, Christopher Vendome
Dissertations, Theses, and Masters Projects
Open source licensing determines how open source systems are reused, distributed, and modified from a legal perspective. While it facilitates rapid development, it can present difficulty for developers in understanding due to the legal language of these licenses. Because of misunderstandings, systems can incorporate licensed code in a way that violates the terms of the license. Such incompatibilities between licensing can result in the inability to reuse a particular library without either relicensing the system or redesigning the architecture of the system. Prior efforts have predominantly focused on license identification or understanding the underlying phenomena without reasoning about compatibility in …
Mixed-Weight Open Locating-Dominating Sets, Robin M. Givens
Mixed-Weight Open Locating-Dominating Sets, Robin M. Givens
Dissertations, Theses, and Masters Projects
The detection and location of issues in a network is a common problem encompassing a wide variety of research areas. Location-detection problems have been studied for wireless sensor networks and environmental monitoring, microprocessor fault detection, public utility contamination, and finding intruders in buildings. Modeling these systems as a graph, we want to find the smallest subset of nodes that, when sensors are placed at those locations, can detect and locate any anomalies that arise. One type of set that solves this problem is the open locating-dominating set (OLD-set), a set of nodes that forms a unique and nonempty neighborhood with …
Automating Software Development For Mobile Computing Platforms, Kevin Patrick Moran
Automating Software Development For Mobile Computing Platforms, Kevin Patrick Moran
Dissertations, Theses, and Masters Projects
Mobile devices such as smartphones and tablets have become ubiquitous in today's computing landscape. These devices have ushered in entirely new populations of users, and mobile operating systems are now outpacing more traditional "desktop" systems in terms of market share. The applications that run on these mobile devices (often referred to as "apps") have become a primary means of computing for millions of users and, as such, have garnered immense developer interest. These apps allow for unique, personal software experiences through touch-based UIs and a complex assortment of sensors. However, designing and implementing high quality mobile apps can be a …
Exploiting Power For Smartphone Security And Privacy, Qing Yang
Exploiting Power For Smartphone Security And Privacy, Qing Yang
Dissertations, Theses, and Masters Projects
Power consumption has become a key issue for smartphone security and privacy protection. In this dissertation, we propose to exploit power for smartphone security, as well as to optimize energy consumption for smartphone privacy. First, we show that public USB charging stations pose a significant privacy risk to smartphone users. We present a side-channel attack that allows a charging station to identify which webpages are loaded while the smartphone is charging. to evaluate this side-channel, we collected power traces of Alexa top 50 websites on multiple smartphones under several conditions, including: varied battery charging level, browser cache enabled/disabled, taps/no taps …
Automatically Documenting Software Artifacts, Boyang Li
Automatically Documenting Software Artifacts, Boyang Li
Dissertations, Theses, and Masters Projects
Software artifacts, such as database schema and unit test cases, constantly change during evolution and maintenance of software systems. Co-evolution of code and DB schemas in Database-Centric Applications (DCAs) often leads to two types of challenging scenarios for developers, where (i) changes to the DB schema need to be incorporated in the source code, and (ii) maintenance of a DCAs code requires understanding of how the features are implemented by relying on DB operations and corresponding schema constraints. On the other hand, the number of unit test cases often grows as new functionality is introduced into the system, and maintaining …