Physical Sciences and Mathematics Commons^™

Camera Viewpoint Invariant Vehicular Traffic Segmentation And Classification, Jeffrey B. Flora

Electrical & Computer Engineering Theses & Dissertations

The goal of this intelligent transportation systems work is to develop a computer vision method that is view angle independent for segmenting and classifying vehicular traffic on highway systems. In order to achieve this goal, this work implements an algorithm for vehicle segmentation, feature extraction, and classification using the existing Virginia Department of Transportation (VDOT) infrastructure on networked traffic cameras. The VDOT traffic video is analyzed for vehicle detection and segmentation using an adaptive Gaussian mixture model algorithm. Speed estimation is performed using a single camera calibration. Size and shape features from morphological properties and texture features from histogram of …

Transparent Spectrum Co-Access In Cognitive Radio Networks, Jonathan Daniel Backens

Electrical & Computer Engineering Theses & Dissertations

The licensed wireless spectrum is currently under-utilized by as much as 85%. Cognitive radio networks have been proposed to employ dynamic spectrum access to share this under-utilized spectrum between licensed primary user transmissions and unlicensed secondary user transmissions. Current secondary user opportunistic spectrum access methods, however, remain limited in their ability to provide enough incentive to convince primary users to share the licensed spectrum, and they rely on primary user absence to guarantee secondary user performance. These challenges are addressed by developing a Dynamic Spectrum Co-Access Architecture (DSCA) that allows secondary user transmissions to co-access transparently and concurrently with primary …

Impact Of Primary User Activity On The Performance Of Energy-Based Spectrum Sensing In Cognitive Radio Systems, Sara L. Macdonald

Electrical & Computer Engineering Theses & Dissertations

Increasing numbers of wireless devices and mobile data requirements have led to a spectrum shortage. However spectrum utilization percentages are often low due to the current static spectrum allocation process where primary users (PUs) are given exclusive use to spectrum. Several mechanisms to increase spectrum utilization have been proposed including opportunistic spectrum access (OSA). Cognitive Radio (CR) is an emerging concept in wireless communication systems that aims to enable OSA in licensed frequencies by secondary users (SUs). CR systems are expected to sense the spectrum in order to determine if the PU is transmitting. Therefore OSA performance relies on the …

Performance Analysis For Wimax Wireless Systems With Multiple Receive Antennas, Selcuk Taskin

Electrical & Computer Engineering Theses & Dissertations

Broadband wireless access has become the best way to meet the growing demand for fast Internet connections. WiMAX is one of the most promising broadband access technologies that allows fast deployment as well as low maintenance costs. WiMAX allows efficient use available bandwidth by using orthogonal frequency division multiplexing (OFDM) which is an efficient multi-carrier modulation technique. Diversity is a method for improving the reliability of a signal in fading environments by using two or more communication channels and is usually achieved by multiple antenna techniques.

In this thesis, receiver side diversity combining methods are studied and the performance of …

Electronic Warfare By Using Unmanned Aerial Vehicles, Aydin Meric

Electrical & Computer Engineering Theses & Dissertations

Technology continues to evolve rapidly by the day. Developments in technology should be followed closely if a country wants to become more powerful. Nowadays nobody can afford to ignore the importance of Electronic Warfare and Unmanned Aerial Vehicles (UAV) in military applications. Both of them play a crucial role in military operations that they can change the course of a war.

There are different kinds of Electronic Warfare methods that can be applied according to the situations and any evolving circumstances. In the beginning Electronic Warfare was used mainly for defensive purposes, but these days Electronic Warfare is used for …

A Genetic Algorithm Approach For Optimized Routing, Pavithra Gudur

Electrical & Computer Engineering Theses & Dissertations

Genetic Algorithms find several applications in a variety of fields, such as engineering, management, finance, chemistry, scheduling, data mining and so on, where optimization plays a key role. This technique represents a numerical optimization technique that is modeled after the natural process of selection based on the Darwinian principle of evolution. The Genetic Algorithm (GA) is one among several optimization techniques and attempts to obtain the desired solution by generating a set of possible candidate solutions or populations. These populations are then compared and the best solutions from the set are retained. Subsequently, new candidate solutions are produced, and the …

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 …

Fault-Tolerance And Recovery In Wireless Sensor Networks, Kevin M. Somervill

Electrical & Computer Engineering Theses & Dissertations

The topic of Wireless Sensor Networks (WSNs) has gained considerable attention in the research community due to the variety of applications and interesting challenges in developing and deploying such networks. The typical WSN is significantly energy constrained and often deployed in harsh or even hostile environments, resulting in sensor nodes that are prone to failure. Failing nodes alter the topology of the network resulting in segmented routing paths and lost messages, ultimately reducing network efficiency. These issues spur the desire to develop energy-efficient, Fault-Tolerant (FT) algorithms that enable the network to persist in spite of the failed nodes. This work …

Virtual Wired Transmission Scheme - A Novel Technique For Efficient Mobile Adhoc Networks, Manikya Vinay Rali

Electrical & Computer Engineering Theses & Dissertations

This thesis proposes a method called virtual wired transmission scheme for ad hoc networks. The scheme is an efficient method to improve network performance parameters such as energy efficiency, capacity, interference, network throughput, etc. Performance parameters improvement can be done at different layers of the network architecture for mobile ad hoc networks. However most of the research efforts are concentrated on Physical, MAC and Network layers. In this thesis, a MAC protocol with a major MAC layer modification is proposed in combination with the usage of directional antennas, developing a novel method called virtual wired transmission scheme. In virtual wired …

A Simulation Study Of Convergence Speed For Distributed Codeword Adaptation Algorithms In Cdma Wireless Systems, Sahana Maharjan

Electrical & Computer Engineering Theses & Dissertations

In this thesis we present a side-by-side comparison of interference avoidance (IA) algorithms for distributed codeword adaptation in Code Division Multiple Access (CDMA) systems. In CDMA systems, the interference is determined by the values of the cross-correlation of codewords assigned to users, and various algorithms can be used for codeword optimization. The IA algorithms for codeword adaptation considered are the eigen-algorithm, the Minimum Mean Square Error (MMSE) update, and the adaptive IA algorithm, for which we investigate convergence speed using the extensive simulations of several uplink CDMA system scenarios. The results of this thesis were presented at the Fourth IEEE …

A Hurricane Evacuation Route System Real-Time Monitoring And Distribution Of Load, Anup Khanal

Electrical & Computer Engineering Theses & Dissertations

Hurricane evacuation is one of the major steps in diminishing the devastating effects of hurricanes on lives and properties. The challenge in evacuating a large number of people in a short time is the severe congestion faced in the transportation network, leading to long delays and shortages. Standard hurricane evacuation plans focus on how to best utilize the main arteries. The research challenge is to not overload the fastest routes and to utilize all the routes efficiently. The evacuation routing system proposed in this thesis focuses on distributing the traffic load throughout the network, utilizing alternative routes not considered in …

A Hidden Markov Model Based Approach To Detect Rogue Access Points, Gayathri Shivaraj

Electrical & Computer Engineering Theses & Dissertations

One of the most challenging security concerns for network administrators is the presence of Rogue access points. The challenge is to detect and disable a Rogue access point before it can cause hazardous damage to the network. This thesis proposes a statistically based approach to detect Rogue access points using a Hidden Markov Model, which is applied to passively measure packet-header data collected at a gateway router or any monitoring point. This approach utilizes variations in packet inter-arrival time to differentiate between authorized access points and Rouge access points. This approach used the inter-arrival time of a packet as a …

High-Performance Broadcast And Multicast Protocols For Multi-Radio Multi-Channel Wireless Mesh Networks, Jun Wang

Electrical & Computer Engineering Theses & Dissertations

Recently, wireless mesh networks (WMNs) have attracted much attention. A vast amount of unicast, multicast and broadcast protocols has been developed for WMNs or mobile ad hoc networks (MANETs). First of all, broadcast and multicast in wireless networks are fundamentally different from the way in which wired networks function due to the well-known wireless broadcast/multicast advantage. Moreover, most broadcast and multicast protocols in wireless networks assume a single-radio single-channel and single-rate network model, or a generalized physical model, which does not take into account the impact of interference. This dissertation focuses on high-performance broadcast and multicast protocols designed for multi-radio …

Supporting Protocols For Structuring And Intelligent Information Dissemination In Vehicular Ad Hoc Networks, Filip Cuckov

Electrical & Computer Engineering Theses & Dissertations

The goal of this dissertation is the presentation of supporting protocols for structuring and intelligent data dissemination in vehicular ad hoc networks (VANETs). The protocols are intended to first introduce a structure in VANETs, and thus promote the spatial reuse of network resources. Segmenting a flat VANET in multiple cluster structures allows for more efficient use of the available bandwidth, which can effectively increase the capacity of the network. The cluster structures can also improve the scalability of the underlying communication protocols. The structuring and maintenance of the network introduces additional overhead. The aim is to provide a mechanism for …

Biomarker Identification For Prostate Cancer Using An Efficient Feature Selection Algorithm, Vamsi Krishnam Raju Mantena

Electrical & Computer Engineering Theses & Dissertations

In recent years, there has been an increased interest in using protein mass spectrometry to identify biomarkers that discriminate diseased from healthy individuals. A biomarker is a characteristic that is objectively measured and evaluated as an indicator of normal biological processes, pathological processes, or pharmacological responses to a therapeutic intervention. Identifying biomarkers will be an important step towards disease characterization and patient management. One challenge of biomarker identification is how to handle the high dimensional mass spectral data. In this thesis, we applied an efficient feature selection algorithm to mass spectrometry data obtained from prostate tissue samples to identify prostate …

Extending The Network Life Time In Wsn Using Energy Efficient Algorithm, Venkata Sesha Sai Koundinya Goparaju

Electrical & Computer Engineering Theses & Dissertations

Wireless Sensor networks have many potential applications. These wireless sensor networks necessitate specific design requirements of which energy efficiency is vital. The sensor networks consist of sensor nodes that operate on battery power, and replacement of these batteries is very often a strenuous task, since networks are deployed in areas where the act of replacing the batteries proves impractical.

With the limited available energy of sensor nodes, most of the energy is drained during communication. An energy efficient routing algorithm can prolong the lifetime of the network by gradually depleting the nodes in the network. Many of the routing protocols …

Congestion Mitigation In Wireless Sensor Networks Using Single-Hop Backpressure Algorithm, Vijay Shekar Mangilipalli Gangu Sham

Electrical & Computer Engineering Theses & Dissertations

Wireless sensor networks consist of a group of small components with limited resources allocated to sense the environment and transmit data to the user or interpreter. This concept is technically evolved from Sensors that are basically used to sense the environment around and collect data based on the sensing application incorporated in them. An extension to functionality of the sensors leads to the concept of sensor networks, where, in addition to gathering information at individual sensors, the data is processed and transmitted to a central station or Base station. This concept of transmitting the information from one node to the …

Distributed Cluster-Based Outlier Detection In Wireless Sensor Networks, Swetha Gali

Electrical & Computer Engineering Theses & Dissertations

Wireless sensor networks find several potential applications in a variety of fields, such as environmental monitoring and control, battlefields, surveillance, smart buildings, human health monitoring, etc. These sensor networks consist of a large number of very tiny, inexpensive, and low power sensor nodes, which are deployed in a variety of harsh environments that may result in the sensor data getting corrupted. It is thus critical to detect and report these abnormal values in the sensor data, in order to have a better understanding of the monitored environment. Detection of the abnormal values is of special interest for the sensor network …

Performance Analysis Of Ieee 802.11b Devices In The Presence Of Interference Aware Scheduling-Adaptive Frequency Hopping Enabled Bluetooth Devices, Deepthi Gopalpet

Electrical & Computer Engineering Theses & Dissertations

Wireless Local Area networks (WLAN) and Wireless Personal Area Networks (WPAN) provide complimentary services using the same unlicensed radio frequency band of operation. The 802.11b WLAN operates in the 2.4 GHz band and uses a Direct Sequence Spread Spectrum technique. It is designed to cover large areas ranging up to 100 meters in diameter, which may connect hundreds of computers. Bluetooth (BT) WPAN also operates in the same frequency band as the IEEE 802.lib and it uses a Frequency Hopping Spread Spectrum technique. BT is primarily used for communications between notebooks, palm units and other personal computing devices within relatively …

Fault Arrangements And Their Effect On The Performance Of Wireless Sensor Networks, Dwayne Sayone Blai

Electrical & Computer Engineering Theses & Dissertations

Wireless sensor networks face many reliability challenges. The networks are deployed in open, hostile environments, making them easily susceptible to network failure. As a result, there are countless faults that can occur in sensor networks, from component failure to outside attacks. Outside attacks take place when an adversary gains control over a node or set of nodes in the network. Outside attackers can destroy a network in numerous ways such as random attacks, clustering attacks, search-based attacks, etc. The method and strategy used in each of these attacks directly affects the network's reliability. Understanding how these adversaries are positioned is …

Fault Modeling In Wireless Sensor Networks, Ahmed A. Elmiligui

Electrical & Computer Engineering Theses & Dissertations

A large amount of research has been done in the area of wireless sensor networks (WSN), but not much work has been done in modeling the fault tolerance and reliability of these networks. In this thesis, the fault tolerance of a WSN to node failures is studied and an analytical reliability model of the network is derived. A valid reliability model of a network could reveal an estimate of the network's performance before it is deployed.

A wireless sensor network was modeled as a k-out-of-n system and a generic fault tolerant framework for the network in terms of node losses …

An Operational Model For Mobile Sensor Cloud Management, Indrajeet Kalyankar

Electrical & Computer Engineering Theses & Dissertations

Mobile sensors provide a safe, cost effective method for gathering information in hazardous environments. When the hazardous environment is either unexplored, such as the surface of Mars, or unanticipated, such as the result of chemical contamination, it is desirable for a system to gather information with a minimal amount of outside control (localization, decision control, etc.) and prepositioned sensors. If one takes a look at the number of the sensors deployed on a scale, at the lower end is the sole, multipurpose sensor unit. The upper end deals with hordes of inexpensive, expendable sensors. In the middle, a cluster of …

A Multilane Pipelined Architecture For Real Time Enhancement Of Color Video Streams, Adam Redd Livingston

Electrical & Computer Engineering Theses & Dissertations

Video stream enhancement is a key fixture in a wide variety of applications from video surveillance, automatic navigation, medical imagery, to facial/object recognition systems. When a video stream contains non-uniform lighting it can be difficult to obtain what is in the darker regions without over enhancing brighter regions. The Adaptive and Integrated Neighborhood Dependant Approach for Nonlinear Enhancement (AINDANE) algorithm combines a tunable nonlinear transfer function, convolution by a multi-scale Gaussian kernel, and tunable contrast enhancement to address this problem for a single image. Luminance values are tuned based on the global cumulative distribution function (CDF) of an image. Contrast …

Tuqr: A Topology Unaware Qos Routing Protocol For Manets, Ibrahim Zagli

Electrical & Computer Engineering Theses & Dissertations

In this thesis, the main purpose is to design a new Quality of Service (QoS) Routing Protocol for Mobile ad-hoc Networks that improves packet delivery ratio in QoS constrained communication in comparison to current well known protocols by using distributed multi-path routing. To accomplish that, a new approach to the QoS routing in Mobile ad hoc Networks (MANET) is developed to reduce the effects of the distrustful environment of MANET by keeping a number of suitable paths as high as possible and distributing the decision mechanism among the nodes on the path.

In most current protocols that mainly evaluate and …

Reversing Ticket Based Probing (Rtbp) Routing For Manet, Turgut Yucel

Electrical & Computer Engineering Theses & Dissertations

The delay-constrained maximum-bandwidth routing problem in MANET (Mobile Ad hoc Networks) is to find the maximum bandwidth path which satisfies a given delay constraint. The research challenge for this problem is that the networking information used for routing may be imprecise. The Ticket-Based Probing (TBP) routing algorithm provides a heuristic approach by using two types of ticket. In this thesis a Reversing Ticket-based Probing (RTBP) routing algorithm is proposed. The RTBP has two novel features compared to the original ticket based probing algorithms. The first feature is using just one type ticket, instead of two types of ticket. RTBP generates …

The Reliability Of The Computer Communication Networks Including Mobile Nodes, Sahin Yasar

Electrical & Computer Engineering Theses & Dissertations

The wireless computer networks have an uncertainty in their structures aside from their big advantages for the users. The environmental conditions, changing locations of the mobile hosts and the changing components in the system can easily affect their reliability. In order to know a system capability performing its functions, keep the reliability at a certain level and/or detect the deficiency of the system, it is necessary to analyze the reliability of a computer communication network including the wired and wireless parts. But the above reasons also make the analysis and a unique solution difficult so a set of algorithms is …

Mobility-Pattern Based Localization Update Algorithm For Mobile Wireless Sensor Networks, Mohammad Yacoub Al-Laho

Electrical & Computer Engineering Theses & Dissertations

In mobile wireless sensor networks, sensors move in the monitored area at any direction and speed. Unlike many other networking hosts, sensor nodes do not have global addresses. They are often identified by using a location-based addressing scheme. Therefore, it is important to have the knowledge of the sensor location indicating where the data came from. In this thesis, three localization update algorithms were designed, Specifically, a sensor movement is divided into three states: Pause, Linear, and Random. Each state adopts different localization update algorithm. Since complex movement involves different mobility patterns, a state transition model is developed to …

Image Compression By Vector Quantization Of Dct Coefficients Using A Self-Organizing Neural Network, Kirankumar Boyapati

Electrical & Computer Engineering Theses & Dissertations

Image compression is used to remove different types of redundancies and irrelevant information in an image so that the space required for storing the image is minimized. Conventional transform based techniques remove the redundancies between adjacent pixels and irrelevant information in the image but fail to remove the redundancies between different parts of the image. There are techniques like vector quantization, which take care of the redundant information in different parts of the image, but fail to remove the irrelevant information in the image. In this thesis a new technique for lossy digital image compression is proposed which is a …

Programmable Process Flow Networks, Filip D. Cuckov

Electrical & Computer Engineering Theses & Dissertations

A model that introduces programmability to processes occurring in a cargo terminal simulation through the use of a process language is presented in this thesis. The model provides a means for a straight-forward definition, and redefinition of changing processes, their incorporation in the simulation architecture and efficient execution. The model was built to investigate a solution for transforming the cargo terminal simulation CPortS into a process-oriented simulation without hard-coded processes. The approach taken separates the system into an architecture and a set of processes which utilize and interact with the architecture's resources and infrastructure. The processes that take place within …

Hierarchical Hybrid Multicast An End System Multicast Algorithm Approach, Guillermo Loaisiga

Electrical & Computer Engineering Theses & Dissertations

Due to the rapid development in the computer and communication technologies, the Internet is experiencing an increasing demand of high-speed, real-time distributed applications, such as live streaming multimedia, videoconferencing, distributed simulations, and multiparty games. Multicast is an efficient transmission mechanism to support these applications. Historically, IP Multicast (IPM) has provided multicast support with well-known benefits, especially in bandwidth savings. However, it has experienced little deployment due to economic and architectural limitations.

Overlay multicast holds promise for the implementation of large scale Internet multicast services. An overlay network is a virtual topology constructed on top of the Internet infrastructure. This concept …