UNT Theses and Dissertations - 128 Matching Results

Search Results

prev Results: 21 - 44 next
open access

A Dual Dielectric Approach for Performance Aware Reduction of Gate Leakage in Combinational Circuits

Description: Design of systems in the low-end nanometer domain has introduced new dimensions in power consumption and dissipation in CMOS devices. With continued and aggressive scaling, using low thickness SiO2 for the transistor gates, gate leakage due to gate oxide direct tunneling current has emerged as the major component of leakage in the CMOS circuits. Therefore, providing a solution to the issue of gate oxide leakage has become one of the key concerns in achieving low power and high performance CMOS … more
Date: May 2006
Creator: Mukherjee, Valmiki
Item Type: Refine your search to only Thesis or Dissertation
Partner: UNT Libraries

Using Reinforcement Learning in Partial Order Plan Space

Description: Partial order planning is an important approach that solves planning problems without completely specifying the orderings between the actions in the plan. This property provides greater flexibility in executing plans; hence making the partial order planners a preferred choice over other planning methodologies. However, in order to find partially ordered plans, partial order planners perform a search in plan space rather than in space of world states and an uninformed search in plan space leads … more
Access: Restricted to UNT Community Members. Login required if off-campus.
Date: May 2006
Creator: Ceylan, Hakan
Item Type: Refine your search to only Thesis or Dissertation
Partner: UNT Libraries
open access

VLSI Architecture and FPGA Prototyping of a Secure Digital Camera for Biometric Application

Description: This thesis presents a secure digital camera (SDC) that inserts biometric data into images found in forms of identification such as the newly proposed electronic passport. However, putting biometric data in passports makes the data vulnerable for theft, causing privacy related issues. An effective solution to combating unauthorized access such as skimming (obtaining data from the passport's owner who did not willingly submit the data) or eavesdropping (intercepting information as it moves from… more
Date: August 2006
Creator: Adamo, Oluwayomi Bamidele
Item Type: Refine your search to only Thesis or Dissertation
Partner: UNT Libraries
open access

Resource Management in Wireless Networks

Description: A local call admission control (CAC) algorithm for third generation wireless networks was designed and implemented, which allows for the simulation of network throughput for different spreading factors and various mobility scenarios. A global CAC algorithm is also implemented and used as a benchmark since it is inherently optimized; it yields the best possible performance but has an intensive computational complexity. Optimized local CAC algorithm achieves similar performance as global CAC algo… more
Date: August 2006
Creator: Arepally, Anurag
Item Type: Refine your search to only Thesis or Dissertation
Partner: UNT Libraries
open access

Modeling Infectious Disease Spread Using Global Stochastic Field Simulation

Description: Susceptibles-infectives-removals (SIR) and its derivatives are the classic mathematical models for the study of infectious diseases in epidemiology. In order to model and simulate epidemics of an infectious disease, a global stochastic field simulation paradigm (GSFS) is proposed, which incorporates geographic and demographic based interactions. The interaction measure between regions is a function of population density and geographical distance, and has been extended to include demographic and… more
Date: August 2006
Creator: Venkatachalam, Sangeeta
Item Type: Refine your search to only Thesis or Dissertation
Partner: UNT Libraries
open access

Natural Language Interfaces to Databases

Description: Natural language interfaces to databases (NLIDB) are systems that aim to bridge the gap between the languages used by humans and computers, and automatically translate natural language sentences to database queries. This thesis proposes a novel approach to NLIDB, using graph-based models. The system starts by collecting as much information as possible from existing databases and sentences, and transforms this information into a knowledge base for the system. Given a new question, the system wil… more
Date: December 2006
Creator: Chandra, Yohan
Item Type: Refine your search to only Thesis or Dissertation
Partner: UNT Libraries
open access

An Approach Towards Self-Supervised Classification Using Cyc

Description: Due to the long duration required to perform manual knowledge entry by human knowledge engineers it is desirable to find methods to automatically acquire knowledge about the world by accessing online information. In this work I examine using the Cyc ontology to guide the creation of Naïve Bayes classifiers to provide knowledge about items described in Wikipedia articles. Given an initial set of Wikipedia articles the system uses the ontology to create positive and negative training sets for the… more
Date: December 2006
Creator: Coursey, Kino High
Item Type: Refine your search to only Thesis or Dissertation
Partner: UNT Libraries
open access

Comparative Study of RSS-Based Collaborative Localization Methods in Wireless Sensor Networks

Description: In this thesis two collaborative localization techniques are studied: multidimensional scaling (MDS) and maximum likelihood estimator (MLE). A synthesis of a new location estimation method through a serial integration of these two techniques, such that an estimate is first obtained using MDS and then MLE is employed to fine-tune the MDS solution, was the subject of this research using various simulation and experimental studies. In the simulations, important issues including the effects of sens… more
Date: December 2006
Creator: Koneru, Avanthi
Item Type: Refine your search to only Thesis or Dissertation
Partner: UNT Libraries
open access

CLUE: A Cluster Evaluation Tool

Description: Modern high performance computing is dependent on parallel processing systems. Most current benchmarks reveal only the high level computational throughput metrics, which may be sufficient for single processor systems, but can lead to a misrepresentation of true system capability for parallel systems. A new benchmark is therefore proposed. CLUE (Cluster Evaluator) uses a cellular automata algorithm to evaluate the scalability of parallel processing machines. The benchmark also uses algorithmic v… more
Date: December 2006
Creator: Parker, Brandon S.
Item Type: Refine your search to only Thesis or Dissertation
Partner: UNT Libraries
open access

Energy-Aware Time Synchronization in Wireless Sensor Networks

Description: I present a time synchronization algorithm for wireless sensor networks that aims to conserve sensor battery power. The proposed method creates a hierarchical tree by flooding the sensor network from a designated source point. It then uses a hybrid algorithm derived from the timing-sync protocol for sensor networks (TSPN) and the reference broadcast synchronization method (RBS) to periodically synchronize sensor clocks by minimizing energy consumption. In multi-hop ad-hoc networks, a depleted … more
Date: December 2006
Creator: Saravanos, Yanos
Item Type: Refine your search to only Thesis or Dissertation
Partner: UNT Libraries
open access

Grid-based Coordinated Routing in Wireless Sensor Networks

Description: Wireless sensor networks are battery-powered ad-hoc networks in which sensor nodes that are scattered over a region connect to each other and form multi-hop networks. These nodes are equipped with sensors such as temperature sensors, pressure sensors, and light sensors and can be queried to get the corresponding values for analysis. However, since they are battery operated, care has to be taken so that these nodes use energy efficiently. One of the areas in sensor networks where an energy analy… more
Date: December 2006
Creator: Sawant, Uttara
Item Type: Refine your search to only Thesis or Dissertation
Partner: UNT Libraries
open access

Power-benefit analysis of erasure encoding with redundant routing in sensor networks.

Description: One of the problems sensor networks face is adversaries corrupting nodes along the path to the base station. One way to reduce the effect of these attacks is multipath routing. This introduces some intrusion-tolerance in the network by way of redundancy but at the cost of a higher power consumption by the sensor nodes. Erasure coding can be applied to this scenario in which the base station can receive a subset of the total data sent and reconstruct the entire message packet at its end. This th… more
Date: December 2006
Creator: Vishwanathan, Roopa
Item Type: Refine your search to only Thesis or Dissertation
Partner: UNT Libraries
open access

Timing and Congestion Driven Algorithms for FPGA Placement

Description: Placement is one of the most important steps in physical design for VLSI circuits. For field programmable gate arrays (FPGAs), the placement step determines the location of each logic block. I present novel timing and congestion driven placement algorithms for FPGAs with minimal runtime overhead. By predicting the post-routing timing-critical edges and estimating congestion accurately, this algorithm is able to simultaneously reduce the critical path delay and the minimum number of routing trac… more
Date: December 2006
Creator: Zhuo, Yue
Item Type: Refine your search to only Thesis or Dissertation
Partner: UNT Libraries

Comparison and Evaluation of Existing Analog Circuit Simulator using Sigma-Delta Modulator

Description: In the world of VLSI (very large scale integration) technology, there are many different types of circuit simulators that are used to design and predict the circuit behavior before actual fabrication of the circuit. In this thesis, I compared and evaluated existing circuit simulators by considering standard benchmark circuits. The circuit simulators which I evaluated and explored are Ngspice, Tclspice, Winspice (open source) and Spectre® (commercial). I also tested standard benchmarks using the… more
Access: Restricted to UNT Community Members. Login required if off-campus.
Date: December 2006
Creator: Ale, Anil Kumar
Item Type: Refine your search to only Thesis or Dissertation
Partner: UNT Libraries

A Language and Visual Interface to Specify Complex Spatial Pattern Mining

Description: The emerging interests in spatial pattern mining leads to the demand for a flexible spatial pattern mining language, on which easy to use and understand visual pattern language could be built. It is worthwhile to define a pattern mining language called LCSPM to allow users to specify complex spatial patterns. I describe a proposed pattern mining language in this paper. A visual interface which allows users to specify the patterns visually is developed. Visual pattern queries are translated into… more
Access: Restricted to UNT Community Members. Login required if off-campus.
Date: December 2006
Creator: Li, Xiaohui
Item Type: Refine your search to only Thesis or Dissertation
Partner: UNT Libraries

A Multi-Variate Analysis of SMTP Paths and Relays to Restrict Spam and Phishing Attacks in Emails

Description: The classifier discussed in this thesis considers the path traversed by an email (instead of its content) and reputation of the relays, features inaccessible to spammers. Groups of spammers and individual behaviors of a spammer in a given domain were analyzed to yield association patterns, which were then used to identify similar spammers. Unsolicited and phishing emails were successfully isolated from legitimate emails, using analysis results. Spammers and phishers are also categorized into se… more
Access: Restricted to UNT Community Members. Login required if off-campus.
Date: December 2006
Creator: Palla, Srikanth
Item Type: Refine your search to only Thesis or Dissertation
Partner: UNT Libraries

Design and Optimization of Components in a 45nm CMOS Phase Locked Loop

Description: A novel scheme of optimizing the individual components of a phase locked loop (PLL) which is used for stable clock generation and synchronization of signals is considered in this work. Verilog-A is used for the high level system design of the main components of the PLL, followed by the individual component wise optimization. The design of experiments (DOE) approach to optimize the analog, 45nm voltage controlled oscillator (VCO) is presented. Also a mixed signal analysis using the analog and di… more
Access: Restricted to UNT Community Members. Login required if off-campus.
Date: December 2006
Creator: Sarivisetti, Gayathri
Item Type: Refine your search to only Thesis or Dissertation
Partner: UNT Libraries

Modeling and reduction of gate leakage during behavioral synthesis of nanoscale CMOS circuits.

Description: The major sources of power dissipation in a nanometer CMOS circuit are capacitive switching, short-circuit current, static leakage and gate oxide tunneling. However, with the aggressive scaling of technology the gate oxide direct tunneling current (gate leakage) is emerging as a prominent component of power dissipation. For sub-65 nm CMOS technology where the gate oxide (SiO2) thickness is very low, the direct tunneling current is the major form of tunneling. There are two contribution parts in… more
Access: Restricted to the UNT Community Members at a UNT Libraries Location.
Date: May 2006
Creator: Velagapudi, Ramakrishna
Item Type: Refine your search to only Thesis or Dissertation
Partner: UNT Libraries
open access

General Purpose Programming on Modern Graphics Hardware

Description: I start with a brief introduction to the graphics processing unit (GPU) as well as general-purpose computation on modern graphics hardware (GPGPU). Next, I explore the motivations for GPGPU programming, and the capabilities of modern GPUs (including advantages and disadvantages). Also, I give the background required for further exploring GPU programming, including the terminology used and the resources available. Finally, I include a comprehensive survey of previous and current GPGPU work, a… more
Date: May 2008
Creator: Fleming, Robert
Item Type: Refine your search to only Thesis or Dissertation
Partner: UNT Libraries
open access

Models to Combat Email Spam Botnets and Unwanted Phone Calls

Description: With the amount of email spam received these days it is hard to imagine that spammers act individually. Nowadays, most of the spam emails have been sent from a collection of compromised machines controlled by some spammers. These compromised computers are often called bots, using which the spammers can send massive volume of spam within a short period of time. The motivation of this work is to understand and analyze the behavior of spammers through a large collection of spam mails. My research … more
Date: May 2008
Creator: Husna, Husain
Item Type: Refine your search to only Thesis or Dissertation
Partner: UNT Libraries
open access

General Nathan Twining and the Fifteenth Air Force in World War II

Description: General Nathan F. Twining distinguished himself in leading the American Fifteenth Air Force during the last full year of World War II in the European Theatre. Drawing on the leadership qualities he had already shown in combat in the Pacific Theatre, he was the only USAAF leader who commanded three separate air forces during World War II. His command of the Fifteenth Air Force gave him his biggest, longest lasting, and most challenging experience of the war, which would be the foundation for t… more
Date: May 2008
Creator: Hutchins, Brian
Item Type: Refine your search to only Thesis or Dissertation
Partner: UNT Libraries
open access

A CAM-Based, High-Performance Classifier-Scheduler for a Video Network Processor.

Description: Classification and scheduling are key functionalities of a network processor. Network processors are equipped with application specific integrated circuits (ASIC), so that as IP (Internet Protocol) packets arrive, they can be processed directly without using the central processing unit. A new network processor is proposed called the video network processor (VNP) for real time broadcasting of video streams for IP television (IPTV). This thesis explores the challenge in designing a combined class… more
Date: May 2008
Creator: Tarigopula, Srivamsi
Item Type: Refine your search to only Thesis or Dissertation
Partner: UNT Libraries
open access

Non-Uniform Grid-Based Coordinated Routing in Wireless Sensor Networks

Description: Wireless sensor networks are ad hoc networks of tiny battery powered sensor nodes that can organize themselves to form self-organized networks and collect information regarding temperature, light, and pressure in an area. Though the applications of sensor networks are very promising, sensor nodes are limited in their capability due to many factors. The main limitation of these battery powered nodes is energy. Sensor networks are expected to work for long periods of time once deployed and it bec… more
Date: August 2008
Creator: Kadiyala, Priyanka
Item Type: Refine your search to only Thesis or Dissertation
Partner: UNT Libraries
open access

Region aware DCT domain invisible robust blind watermarking for color images.

Description: The multimedia revolution has made a strong impact on our society. The explosive growth of the Internet, the access to this digital information generates new opportunities and challenges. The ease of editing and duplication in digital domain created the concern of copyright protection for content providers. Various schemes to embed secondary data in the digital media are investigated to preserve copyright and to discourage unauthorized duplication: where digital watermarking is a viable solutio… more
Date: December 2008
Creator: Naraharisetti, Sahasan
Item Type: Refine your search to only Thesis or Dissertation
Partner: UNT Libraries
Back to Top of Screen