Computer Engineering Commons^™

Self-Stabilizing Leader Election In Dynamic Networks, Hema Piniganti

UNLV Theses, Dissertations, Professional Papers, and Capstones

The leader election problem is one of the fundamental problems in distributed computing. It has applications in almost every domain. In dynamic networks, topology is expected to change frequently. An algorithm A is self-stabilizing if, starting from a completely arbitrary configuration, the network will eventually reach a legitimate configuration.

Note that any self-stabilizing algorithm for the leader election problem is also an algorithm for the dynamic leader election problem, since when the topology of the network changes, we can consider that the algorithm is starting over again from an arbitrary state. There are a number of such algorithms in the …

Self-Stabilizing Group Membership Protocol, Mahesh Subedi

UNLV Theses, Dissertations, Professional Papers, and Capstones

In this thesis, we consider the problem of partitioning a network into groups of bounded diameter.

Given a network of processes X and a constant D, the group partition problem is the problem of finding a D-partition of X, that is, a partition of X into disjoint connected subgraphs, which we call groups, each of diameter no greater than D. The minimal group partition problem is to find a D-partition {G1, ... Gm} of X such that no two groups can be combined; that is, for any Gi and Gj, where i ≠ j, either Gi U Gj is disconnected …

Dynamic Distributed Programming And Applications To Swap Edge Problem, Feven Z. Andemeskel

UNLV Theses, Dissertations, Professional Papers, and Capstones

Link failure is a common reason for disruption in communication networks. If communication between processes of a weighted distributed network is maintained by a spanning tree T, and if one edge e of T fails, communication can be restored by finding a new spanning tree, T’. If the network is 2-edge connected, T’ can always be constructed by replacing e by a single edge, e’, of the network. We refer to e’ as a swap edge of e.

The best swap edge problem is to find the best choice of e’, that is, that e which causes the new spanning …

Reputation-Based Internet Protocol Security: A Multilayer Security Framework For Mobil Ad Hoc Networks, Timothy H. Lacey

Theses and Dissertations

This research effort examines the theory, application, and results for a Reputation-based Internet Protocol Security (RIPSec) framework that provides security for an ad-hoc network operating in a hostile environment. In RIPSec, protection from external threats is provided in the form of encrypted communication links and encryption-wrapped nodes while internal threats are mitigated by behavior grading that assigns reputations to nodes based on their demonstrated participation in the routing process. Network availability is provided by behavior grading and round-robin multipath routing. If a node behaves faithfully, it earns a positive reputation over time. If a node misbehaves (for any number of …

Hijacking User Uploads To Online Persistent Data Repositories For Covert Data Exfiltration, Curtis P. Barnard

Theses and Dissertations

As malware has evolved over the years, it has gone from harmless programs that copy themselves into other executables to modern day botnets that perform bank fraud and identity theft. Modern malware often has a need to communicate back to the author, or other machines that are also infected. Several techniques for transmitting this data covertly have been developed over the years which vary significantly in their level of sophistication. This research creates a new covert channel technique for stealing information from a network by piggybacking on user-generated network traffic. Specifically, steganography drop boxes and passive covert channels are merged …

Architecture And Compiler Support For Leakage Reduction Using Power Gating In Microprocessors, Soumyaroop Roy

USF Tampa Graduate Theses and Dissertations

Power gating is a technique commonly used for runtime leakage reduction in digital CMOS circuits. In microprocessors, power gating can be implemented by using sleep transistors to selectively deactivate circuit modules when they are idle during program execution. In this dissertation, a framework for power gating arithmetic functional units in embedded microprocessors with architecture and compiler support is proposed. During compile time, program regions are identified where one or more functional units are idle and sleep instructions are inserted into the code so that those units can be put to sleep during program execution. Subsequently, when their need is detected …

Asynchronous Mips Processors: Educational Simulations, Robert L. Webb

Master's Theses

The system clock has been omnipresent in most mainstream chip designs. While simplifying many design problems the clock has caused the problems of clock skew, high power consumption, electromagnetic interference, and worst-case performance. In recent years, as the timing constraints of synchronous designs have been squeezed ever tighter, the efficiencies of asynchronous designs have become more attractive. By removing the clock, these issues can be mitigated. How- ever, asynchronous designs are generally more complex and difficult to debug. In this paper I discuss the advantages of asynchronous processors and the specifics of some asynchronous designs, outline the roadblocks to asynchronous …

Deterministic, Efficient Variation Of Circuit Components To Improve Resistance To Reverse Engineering, Daniel F. Koranek

Theses and Dissertations

This research proposes two alternative methods for generating semantically equivalent circuit variants which leave the circuit's internal structure pseudo-randomly determined. Component fusion deterministically selects subcircuits using a component identification algorithm and replaces them using a deterministic algorithm that generates canonical logic forms. Component encryption seeks to alter the semantics of individual circuit components using an encoding function, but preserves the overall circuit semantics by decoding signal values later in the circuit. Experiments were conducted to examine the performance of component fusion and component encryption against representative trials of subcircuit selection-and-replacement and Boundary Blurring, two previously defined methods for circuit obfuscation. …

Developing A Hybrid Virtualization Platform Design For Cyber Warfare And Simulation, Kyle E. Stewart

Theses and Dissertations

Virtualization is a technique used to model and simulate the cyber domain, as well as train and educate. Different types of virtualization techniques exist that each support a unique set of benefits and requirements. This research proposes a novel design that incorporates host and network virtualization concepts for a cyber warfare training platform. At the host level, hybrid virtualization combines full and operating system virtualization techniques in order to leverage the benefits and minimize the drawbacks of each individual technique. Network virtualization allows virtual machines to connect in flexible topologies, but it also incurs additional processing overhead. Quantitative analysis falls …

Wii-Mote Head Tracking: A Three Dimensional Virtual Reality Display, David Fairman

Computer Engineering

The goal of this project is to create a customizable three dimensional virtual reality display on a system available to any non-technical user. This System will use the infrared camera component of a standard Nintendo Wii-mote to track a user's head motions in all six major directions. The virtual reality will be a customizable image projected onto a screen or simply shown on a computer or TV monitor. In order to appear 3-dimensional, the image will continually change according to the position of the user's head. As the user moves their head to the left and right, portions of the …

Max Flow Spill Code Placement Algorithm Implemented In Gcc 4.4.3, Stephen Robert Beard

Computer Engineering

The placement of spill code plays an important role in the register allocator of an optimizing compiler. Many computer architectures possess a register linkage convention that dictates which registers are preserved across function calls and which are not. This project addresses the problem of optimizing spill code that is associated with register linkage conventions.

This algorithm was created by Dr. Chris Lupo and is described in the paper Beyond Register Allocation: a Novel Algorithm for Spill-Code Placement. The algorithm was implemented for GCC 2.5.7 for a PA-RISC architecture [4]. The work in this project will involve porting the existing code …

Measuring Atmospheric Scattering From Digital Images Of Urban Scenery Using Temporal Polarization-Based Vision, Tarek El-Gaaly

Archived Theses and Dissertations

Suspended atmospheric particles (particulate matter) are a form of air pollution that visually degrades urban scenery and is hazardous to human health and the environment. Current environmental monitoring devices are limited in their capability of measuring average particulate matter (PM) over large areas. Quantifying the visual effects of haze in digital images of urban scenery and correlating these effects to PM levels is a vital step in more practically monitoring our environment. Current image haze extraction algorithms remove all the haze from the scene and hence produce unnatural scenes for the sole purpose of enhancing vision. We present two algorithms …

An Extended Configurable Uml Activity Diagram And A Transformation Algorithm For Business Process Reference Modeling, Yosra Osama Badr

Archived Theses and Dissertations

Enterprise Resource Planning (ERP) solutions provide generic off-the-shelf reference models usually known as "best practices". The configuration !individualization of the reference model to meet specific requirements of business end users however, is a difficult task. The available modeling languages do not provide a complete configurable language that could be used to model configurable reference models. More specifically, there is no algorithm that monitors the transformation of configurable UML Activity Diagram (AD) models while preserving the syntactic correctness of the model. To fill these gaps we propose an extended UML AD modeling language which we named Configurable UML Activity Diagram (C-UML …

Hidra: Hierarchical Inter-Domain Routing Architecture, Bryan Clevenger

Master's Theses

As the Internet continues to expand, the global default-free zone (DFZ) forwarding table has begun to grow faster than hardware can economically keep pace with. Various policies are in place to mitigate this growth rate, but current projections indicate policy alone is inadequate. As such, a number of technical solutions have been proposed. This work builds on many of these proposed solutions, and furthers the debate surrounding the resolution to this problem. It discusses several design decisions necessary to any proposed solution, and based on these tradeoffs it proposes a Hierarchical Inter-Domain Routing Architecture - HIDRA, a comprehensive architecture with …

Pretty Lights, Nicholas (Nick) Delmas, Matthew (Matt) Maniaci

Computer Engineering

Digital media players often include a visualization component that allows a user to watch a visualization synchronized to their music or videos. This project uses the visualization plugin API of an existing media playback program (WinAmp) but it displays its visuals using physical LED lights. Instead of outputting visuals to the computer screen, data is sent over USB to a micro controller that runs the LED lights. This project aims to give users a more visceral visual experience than traditional visualizations on the computer screen.

A Secure On-Line Credit Card Transaction Method Based On Kerberos Authentication Protocol, Jung Eun Kim

UNLV Theses, Dissertations, Professional Papers, and Capstones

Nowadays, electronic payment system is an essential part of modern business. Credit cards or debit cards have been widely used for on-site or remote transactions, greatly reducing the need for inconvenient cash transactions. However, there have been a huge number of incidents of credit card frauds over the Internet due to the security weakness of electronic payment system. A number of solutions have been proposed in the past to prevent this problem, but most of them were inconvenient and did not satisfy the needs of cardholders and merchants at the same time.

In this thesis, we present a new secure …

Providing Location Security In Vehicular Ad Hoc Networks, Gongjun Yan

Computer Science Theses & Dissertations

Location is fundamental information in Vehicular Ad-hoc Networks (VANETs). Almost all VANET applications rely on location information. Therefore it is of importance to ensure location information integrity, meaning that location information is original (from the generator), correct (not bogus or fabricated) and unmodified (value not changed). We present validation mechanisms to provide location integrity for VANETs. In the initial mechanism, we assume that all vehicles are equipped with a radar, a GPS receiver, and a transceiver. Since radar has a limited radar range and transceiver has a limited transmission range, we build network cells as a security unit as well …

Handshaking Protocols And Jamming Mechanisms For Blind Rendezvous In A Dynamic Spectrum Access Environment, Aaron A. Gross

Theses and Dissertations

Blind frequency rendezvous is an important process for bootstrapping communications between radios without the use of pre-existing infrastructure or common control channel in a Dynamic Spectrum Access (DSA) environment. In this process, radios attempt to arrive in the same frequency channel and recognize each other’s presence in changing, under-utilized spectrum. This paper refines existing blind rendezvous techniques by introducing a handshaking algorithm for setting up communications once two radios have arrived in the same frequency channel. It then investigates the effect of different jamming techniques on blind rendezvous algorithms that utilize this handshake. The handshake performance is measured by determining …

Utilizing The Digital Fingerprint Method For Secure Key Generation, Jennifer C. Anilao

Theses and Dissertations

This research examines a new way to generate an uncloneable secure key by taking advantage of the delay characteristics of individual transistors. The user profiles the circuit to deduce the glitch count of each output line for each number of selectable buffers added to the circuit. The user can then use this information to generate a specific glitch count on each output line, which is passed to an encryption algorithm as its key. The results detail tests of two configurations for adding a selectable amount of buffers into each glitch circuit in order to induce additional delay. One configuration adds …

Visually Managing Ipsec, Peter J. Dell'accio

Theses and Dissertations

The United States Air Force relies heavily on computer networks to transmit vast amounts of information throughout its organizations and with agencies throughout the Department of Defense. The data take many forms, utilize different protocols, and originate from various platforms and applications. It is not practical to apply security measures specific to individual applications, platforms, and protocols. Internet Protocol Security (IPsec) is a set of protocols designed to secure data traveling over IP networks, including the Internet. By applying security at the network layer of communications, data packets can be secured regardless of what application generated the data or which …

A Distributed Network Logging Topology, Nicholas E. Fritts

Theses and Dissertations

Network logging is used to monitor computer systems for potential problems and threats by network administrators. Research has found that the more logging enabled, the more potential threats can be detected in the logs (Levoy, 2006). However, generally it is considered too costly to dedicate the manpower required to analyze the amount of logging data that it is possible to generate. Current research is working on different correlation and parsing techniques to help filter the data, but these methods function by having all of the data dumped in to a central repository. Central repositories are limited in the amount of …

Codifying Information Assurance Controls For Department Of Defense (Dod) Supervisory Control And Data Acquisition (Scada) Systems (U), Eddie A. Mendezllovet

Theses and Dissertations

Protecting DoD critical infrastructure resources and Supervisory Control and Data Acquisition (SCADA) systems from cyber attacks is becoming an increasingly challenging task. DoD Information Assurance controls provide a sound framework to achieve an appropriate level of confidentiality, integrity, and availability. However, these controls have not been updated since 2003 and currently do not adequately address the security of DoD SCADA systems. This research sampled U.S. Air Force Civil Engineering subject matter experts representing eight Major Commands that manage and operate SCADA systems. They ranked 30 IA controls in three categories, and evaluated eight SCADA specific IA controls for inclusion into …

Developing Cyberspace Data Understanding: Using Crisp-Dm For Host-Based Ids Feature Mining, Joseph R. Erskine

Theses and Dissertations

Current intrusion detection systems generate a large number of specific alerts, but do not provide actionable information. Many times, these alerts must be analyzed by a network defender, a time consuming and tedious task which can occur hours or days after an attack occurs. Improved understanding of the cyberspace domain can lead to great advancements in Cyberspace situational awareness research and development. This thesis applies the Cross Industry Standard Process for Data Mining (CRISP-DM) to develop an understanding about a host system under attack. Data is generated by launching scans and exploits at a machine outfitted with a set of …

Developing An Effective And Efficient Real Time Strategy Agent For Use As A Computer Generated Force, Kurt Weissgerber

Theses and Dissertations

Computer Generated Forces (CGF) are used to represent units or individuals in military training and constructive simulation. The use of CGF significantly reduces the time and money required for effective training. For CGF to be effective, they must behave as a human would in the same environment. Real Time Strategy (RTS) games place players in control of a large force whose goal is to defeat the opponent. The military setting of RTS games makes them an excellent platform for the development and testing of CGF. While there has been significant research in RTS agent development, most of the developed agents …

Unified Role Assignment Framework For Wireless Sensor Networks, Manish Mahendra Kumar Kochhal

Wayne State University Dissertations

Wireless sensor networks are made possible by the continuing improvements in embedded sensor, VLSI, and wireless radio technologies. Currently, one of the important challenges in sensor networks is the design of a systematic network management framework that allows localized and collaborative resource control uniformly across all application services such as sensing, monitoring, tracking, data aggregation, and routing.

The research in wireless sensor networks is currently oriented toward a cross-layer network abstraction that supports appropriate fine or course grained resource controls for energy efficiency. In that regard, we have designed a unified role-based service paradigm for wireless sensor networks. We pursue …

Task Analysis, Modeling, And Automatic Identification Of Elemental Tasks In Robot-Assisted Laparoscopic Surgery, Lavie Pinchas Golenberg

Wayne State University Dissertations

Robotic microsurgery provides many advantages for surgical operations, including tremor filtration, an increase in dexterity, and smaller incisions. There is a growing need for a task analyses on robotic laparoscopic operations to understand better the tasks involved in robotic microsurgery cases. A few research groups have conducted task observations to help systems automatically identify surgeon skill based on task execution. Their gesture analyses, however, lacked depth and their class libraries were composed of ambiguous groupings of gestures that did not share contextual similarities.

A Hierarchical Task Analysis was performed on a four-throw suturing task using a robotic microsurgical platform. Three …

Filter Scheduling Function Model In Internet Server: Resource Configuration, Performance Evaluation And Optimal Scheduling, Minghua Xu

Wayne State University Dissertations

ABSTRACT

FILTER SCHEDULING FUNCTION MODEL IN INTERNET SERVER:

RESOURCE CONFIGURATION, PERFORMANCE EVALUATION AND

OPTIMAL SCHEDULING

by

MINGHUA XU

August 2010

Advisor: Dr. Cheng-Zhong Xu

Major: Computer Engineering

Degree: Doctor of Philosophy

Internet traffic often exhibits a structure with rich high-order statistical properties like selfsimilarity

and long-range dependency (LRD). This greatly complicates the problem of

server performance modeling and optimization. On the other hand, popularity of Internet

has created numerous client-server or peer-to-peer applications, with most of them,

such as online payment, purchasing, trading, searching, publishing and media streaming,

being timing sensitive and/or financially critical. The scheduling policy in Internet servers …

Visualization Of Complex Unsteady 3d Flow: Flowing Seed Points And Dynamically Evolving Seed Curves With Applications To Vortex Visualization In Cfd Simulations Of Ultra Low Reynolds Number Insect Flight, Christopher M. Koehler

Browse all Theses and Dissertations

Three dimensional integration-based geometric visualization is a very powerful tool for analyzing flow phenomena in time dependent vector fields. Streamlines in particular have many perceptual benefits due to their ability to provide a snapshot of the vectors near key features of complex 3D flows at any instant in time. However, streamlines do not lend themselves well to animation. Subtle changes in the vector field at each time step lead to increasingly large changes between streamlines with the same seed point the longer they are integrated. Path lines, which show particle trajectories over time suffer from similar problems when attempting to …

Algorithmic Techniques Employed In The Quantification And Characterization Of Nuclear Magnetic Resonance Spectroscopic Data, Paul Edward Anderson

Browse all Theses and Dissertations

Nuclear magnetic resonance (NMR) based metabolomics is a developing research field with broad applicability, including the identification of biomarkers associated with pathophysiologic changes, sample classification based on the mechanism of toxicity, and clinical diagnosis. Intrinsic to these applications is the need for statistical and computational techniques to facilitate the associated data analysis. Further, a typical 1H NMR spectrum of pure proteins, biofluids, or tissue may contain thousands of resonances (i.e., peaks), thus, a pure visual inspection is insufficient to fully utilize the spectral information.

Common practice within the NMR-based metabolomics community is to evaluate and validate novel algorithms on empirical …

Transmitter Optimization In Multiuser Wireless Systems With Quality Of Service Constraints, Danda B. Rawat

Electrical & Computer Engineering Theses & Dissertations

In this dissertation, transmitter adaptation for optimal resource allocation in wireless communication systems are investigated. First, a multiple access channel model is considered where many transmitters communicate with a single receiver. This scenario is a basic component of a. wireless network in which multiple users simultaneously access the resources of a wireless service provider. Adaptive algorithms for transmitter optimization to meet Quality-of-Service (QoS) requirements in a distributed manner are studied. Second, an interference channel model is considered where multiple interfering transmitter-receiver pairs co-exist such that a given transmitter communicates with its intended receiver in the presence of interference from other …