## 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.

Cognitive Radios (CR) are designed to dynamically recon&#64257;gure their transmission and/or reception parameters to utilize the bandwidth ef&#64257;ciently. With a rapidly &#64258;uctuating radio environment, spectrum management becomes crucial for cognitive radios. In a Cognitive Radio Ad Hoc Network (CRAHN) setting, the sensing and transmission times of the cognitive radio play a more important role because of the decentralized nature of the network. They have a direct impact on the throughput. Due to the tradeoff between throughput and the sensing time, &#64257;nding optimal values for sensing time and transmission time is dif&#64257;cult. In this thesis, a method is proposed to improve …

Contributors
Bapat, Namrata, Syrotiuk, Violet R, Ahn, Gail-Joon, et al.
Created Date
2012

This thesis studies recommendation systems and considers joint sampling and learning. Sampling in recommendation systems is to obtain users' ratings on specific items chosen by the recommendation platform, and learning is to infer the unknown ratings of users to items given the existing data. In this thesis, the problem is formulated as an adaptive matrix completion problem in which sampling is to reveal the unknown entries of a $U\times M$ matrix where $U$ is the number of users, $M$ is the number of items, and each entry of the $U\times M$ matrix represents the rating of a user to an …

Contributors
Zhu, Lingfang, Xue, Guoliang, He, Jingrui, et al.
Created Date
2015

Passwords are ubiquitous and are poised to stay that way due to their relative usability, security and deployability when compared with alternative authentication schemes. Unfortunately, humans struggle with some of the assumptions or requirements that are necessary for truly strong passwords. As administrators try to push users towards password complexity and diversity, users still end up using predictable mangling patterns on old passwords and reusing the same passwords across services; users even inadvertently converge on the same patterns to a surprising degree, making an attacker’s job easier. This work explores using machine learning techniques to pick out strong passwords from …

Contributors
Todd, Margaret Nicole, Xue, Guoliang, Ahn, Gail-Joon, et al.
Created Date
2016

Security has been one of the top concerns in cloud community while cloud resource abuse and malicious insiders are considered as top threats. Traditionally, Intrusion Detection Systems (IDS) and Intrusion Prevention Systems (IPS) have been widely deployed to manipulate cloud security, with the latter one providing additional prevention capability. However, as one of the most creative networking technologies, Software-Defined Networking (SDN) is rarely used to implement IDPS in the cloud computing environment because the lack of comprehensive development framework and processing flow. Simply migration from traditional IDS/IPS systems to SDN environment are not effective enough for detecting and defending malicious …

Contributors
Xiong, Zhengyang, Huang, Dijiang, Xue, Guoliang, et al.
Created Date
2014

Commercial load balancers are often in use, and the production network at Arizona State University (ASU) is no exception. However, because the load balancer uses IP addresses, the solution does not apply to all applications. One such application is Rsyslog. This software processes syslog packets and stores them in files. The loss rate of incoming log packets is high due to the incoming rate of the data. The Rsyslog servers are overwhelmed by the continuous data stream. To solve this problem a software defined networking (SDN) based load balancer is designed to perform a transport-level load balancing over the incoming …

Contributors
Ghaffarinejad, Ashkan, Syrotiuk, Violet R, Xue, Guoliang, et al.
Created Date
2015

Energy management system (EMS) is at the heart of the operation and control of a modern electrical grid. Because of economic, safety, and security reasons, access to industrial grade EMS and real-world power system data is extremely limited. Therefore, the ability to simulate an EMS is invaluable in researching the EMS in normal and anomalous operating conditions. I first lay the groundwork for a basic EMS loop simulation in modern power grids and review a class of cybersecurity threats called false data injection (FDI) attacks. Then I propose a software architecture as the basis of software simulation of the EMS …

Contributors
Created Date
2019

This thesis addresses the ever increasing threat of botnets in the smartphone domain and focuses on the Android platform and the botnets using Online Social Networks (OSNs) as Command and Control (C&C;) medium. With any botnet, C&C; is one of the components on which the survival of botnet depends. Individual bots use the C&C; channel to receive commands and send the data. This thesis develops active host based approach for identifying the presence of bot based on the anomalies in the usage patterns of the user before and after the bot is installed on the user smartphone and alerting the …

Contributors
Kilari, Vishnu Teja, Xue, Guoliang, Ahn, Gail-Joon, et al.
Created Date
2013

New OpenFlow switches support a wide range of network applications, such as firewalls, load balancers, routers, and traffic monitoring. While ternary content addressable memory (TCAM) allows switches to process packets at high speed based on multiple header fields, today's commodity switches support just thousands to tens of thousands of forwarding rules. To allow for finer-grained policies on this hardware, efficient ways to support the abstraction of a switch are needed with arbitrarily large rule tables. To do so, a hardware-software hybrid switch is designed that relies on rule caching to provide large rule tables at low cost. Unlike traditional caching …

Contributors
Alipourfard, Omid, Syrotiuk, Violet R, Richa, Andrea W, et al.
Created Date
2014

There are many applications where the truth is unknown. The truth values are guessed by different sources. The values of different properties can be obtained from various sources. These will lead to the disagreement in sources. An important task is to obtain the truth from these sometimes contradictory sources. In the extension of computing the truth, the reliability of sources needs to be computed. There are models which compute the precision values. In those earlier models Banerjee et al. (2005) Dong and Naumann (2009) Kasneci et al. (2011) Li et al. (2012) Marian and Wu (2011) Zhao and Han (2012) …

Contributors
Jain, Karan, Xue, Guoliang, Sen, Arunabha, et al.
Created Date
2019

Android is currently the most widely used mobile operating system. The permission model in Android governs the resource access privileges of applications. The permission model however is amenable to various attacks, including re-delegation attacks, background snooping attacks and disclosure of private information. This thesis is aimed at understanding, analyzing and performing forensics on application behavior. This research sheds light on several security aspects, including the use of inter-process communications (IPC) to perform permission re-delegation attacks. Android permission system is more of app-driven rather than user controlled, which means it is the applications that specify their permission requirement and the only …

Contributors
Gollapudi, Narasimha Aditya, Dasgupta, Partha, Xue, Guoliang, et al.
Created Date
2014