Engineering Commons^™

Communications With Spectrum Sharing In 5g Networks Via Drone-Mounted Base Stations, Liang Zhang

Dissertations

The fifth generation wireless network is designed to accommodate enormous traffic demands for the next decade and to satisfy varying quality of service for different users. Drone-mounted base stations (DBSs) characterized by high mobility and low cost intrinsic attributes can be deployed to enhance the network capacity. In-band full-duplex (IBFD) is a promising technology for future wireless communications that can potentially enhance the spectrum efficiency and the throughput capacity. Therefore, the following issues have been identified and investigated in this dissertation in order to achieve high spectrum efficiency and high user quality of service.

First, the problem of deploying DBSs …

Quantitative Metrics For Mutation Testing, Amani M. Ayad

Dissertations

Program mutation is the process of generating versions of a base program by applying elementary syntactic modifications; this technique has been used in program testing in a variety of applications, most notably to assess the quality of a test data set. A good test set will discover the difference between the original program and mutant except if the mutant is semantically equivalent to the original program, despite being syntactically distinct.

Equivalent mutants are a major nuisance in the practice of mutation testing, because they introduce a significant amount of bias and uncertainty in the analysis of test results; indeed, mutants …

Analyzing Evolution Of Rare Events Through Social Media Data, Xiaoyu Lu

Dissertations

Recently, some researchers have attempted to find a relationship between the evolution of rare events and temporal-spatial patterns of social media activities. Their studies verify that the relationship exists in both time and spatial domains. However, few of those studies can accurately deduce a time point when social media activities are most highly affected by a rare event because producing an accurate temporal pattern of social media during the evolution of a rare event is very difficult. This work expands the current studies along three directions. Firstly, we focus on the intensity of information volume and propose an innovative clustering …

Optimal Sampling Paths For Autonomous Vehicles In Uncertain Ocean Flows, Andrew J. De Stefan

Dissertations

Despite an extensive history of oceanic observation, researchers have only begun to build a complete picture of oceanic currents. Sparsity of instrumentation has created the need to maximize the information extracted from every source of data in building this picture. Within the last few decades, autonomous vehicles, or AVs, have been employed as tools to aid in this research initiative. Unmanned and self-propelled, AVs are capable of spending weeks, if not months, exploring and monitoring the oceans. However, the quality of data acquired by these vehicles is highly dependent on the paths along which they collect their observational data. The …

Multiframe Coded Computation For Distributed Uplink Channel Decoding, Brinell F. Monteiro

Theses

The latest 5G technology in wireless communication has led to an increasing demand for higher data rates and low latencies. The overall latency of the system in a cloud radio access network is greatly affected by the decoding latency in the uplink channel. Various proposed solutions suggest using network function virtualization (NFV). NFV is the process of decoupling the network functions from hardware appliances. This provides the exibility to implement distributed computing and network coding to effectively reduce the decoding latency and improve the reliability of the system. To ensure the system is cost effective, commercial off the shelf (COTS) …

High-Speed Data Communications For Vehicular Networks Using Free-Space Optical Communications, Yagiz Kaymak

Dissertations

The demand for high-speed Internet access for vehicles, such as high-speed trains (HSTs) and cars, is on the rise. Several Internet access technologies that use radio frequency are being considered for vehicular networking. Radio-frequency communications technologies cannot provide high data rates due to interference, bandwidth limitations, and the inherent limited data rates of radio technology. Free-space optical communications (FSOC) is an alternative approach and a line-of-sight (LOS) technology that uses modulated light to transfer data between two free-space optical (FSO) transceivers. FSOC systems for vehicular networks are expected to provide data rates in the range of Gbps for stationary and …

Computational Intelligence In Steganography: Adaptive Image Watermarking, Xin Zhong

Dissertations

Digital image watermarking, as an extension of traditional steganography, refers to the process of hiding certain messages into cover images. The transport image, called marked-image or stego-image, conveys the hidden messages while appears visibly similar to the cover-image. Therefore, image watermarking enables various applications such as copyright protection and covert communication. In a watermarking scheme, fidelity, capacity and robustness are considered as crucial factors, where fidelity measures the similarity between the cover- and marked-images, capacity measures the maximum amount of watermark that can be embedded, and robustness concerns the watermark extraction under attacks on the marked-image. Watermarking techniques are often …

Design, Analysis And Optimization Of Visible Light Communications Based Indoor Access Systems For Mobile And Internet Of Things Applications, Sihua Shao

Dissertations

Demands for indoor broadband wireless access services are expected to outstrip the spectrum capacity in the near-term "spectrum crunch". Deploying additional femtocells to address "spectrum crunch" is cost-inefficient due to the "backhaul challenge" and the exorbitant system maintenance. According to an Alcatel-Lucent report, most mobile Internet access traffic happens indoors. To alleviate the "spectrum crunch" and the "backhaul challenge" problems, visible light communication (VLC) emerges as an attractive candidate for indoor wireless access in the 5G architecture. In particular, VLC utilizes LED or fluorescent lamps to send out imperceptible flickering light that can be captured by a smart phone camera …

Preemptive Efficient Queueing For Scheduling Deadline-Bound Data Center Flows, Vinaykrishna Gopalakrishna

Theses

This thesis introduces a new deadline aware flow scheduling scheme called Preemptive Efficient Queuing (PEQ). Unlike other schemes which use policies like EDF, SJF or fair share, this scheme aims to procrastinate flows as much as they can afford to, while keeping with their deadlines. Thereby, PEQ prioritizes more urgent flows that have shorter time to procrastinate, or cushion time. Results of PEQ are compared with state-of-the-art schemes for the transport of data-center flows, such as Preemptive Distributed Quick (PDQ) and Deadline-Driven Delivery (D³). The results show that PEQ outperforms D³ and PDQ. We identify results …

Multi-Population-Based Differential Evolution Algorithm For Optimization Problems, Ishani Chatterjee

Theses

A differential evolution (DE) algorithm is an evolutionary algorithm for optimization problems over a continuous domain. To solve high dimensional global optimization problems, this work investigates the performance of differential evolution algorithms under a multi-population strategy. The original DE algorithm generates an initial set of suitable solutions. The multi-population strategy divides the set into several subsets. These subsets evolve independently and connect with each other according to the DE algorithm. This helps in preserving the diversity of the initial set. Furthermore, a comparison of combination of different mutation techniques on several optimization algorithms is studied to verify their performance. Finally, …

Decision Tree Rule-Based Feature Selection For Imbalanced Data, Haoyue Liu

Theses

A class imbalance problem appears in many real world applications, e.g., fault diagnosis, text categorization and fraud detection. When dealing with an imbalanced dataset, feature selection becomes an important issue. To address it, this work proposes a feature selection method that is based on a decision tree rule and weighted Gini index. The effectiveness of the proposed methods is verified by classifying a dataset from Santander Bank and two datasets from UCI machine learning repository. The results show that our methods can achieve higher Area Under the Curve (AUC) and F-measure. We also compare them with filter-based feature selection approaches, …

Online Algorithms For Content Caching: An Economic Perspective, Ammar Gharaibeh

Dissertations

Content Caching at intermediate nodes, such that future requests can be served without going back to the origin of the content, is an effective way to optimize the operations of computer networks. Therefore, content caching reduces the delivery delay and improves the users’ Quality of Experience (QoE). The current literature either proposes offline algorithms that have complete knowledge of the request profile a priori, or proposes heuristics without provable performance. In this dissertation, online algorithms are presented for content caching in three different network settings: the current Internet Network, collaborative multi-cell coordinated network, and future Content Centric Networks (CCN). Due …

Source-Channel Coding For Coordination Over A Noisy Two-Node Network, Sarah A. Obead

Theses

Recently, the concept of coordinating actions between distributed agents has emerged in the information theory literature. It was first introduced by Cuff in 2008 for the point-to-point case of coordination. However, Cuff’s work and the vast majority of the follow-up research are based on establishing coordination over noise-free communication links. In contrast, this thesis investigates the open problem of coordination over noisy point-to-point links. The aim of this study is to examine Shannon’s source-channel separation theorem in the context of coordination. To that end, a general joint scheme to achieve the strong notion of coordination over a discrete memoryless channel …

Subspace Methods For Portfolio Design, Onur Yilmaz

Dissertations

Financial signal processing (FSP) is one of the emerging areas in the field of signal processing. It is comprised of mathematical finance and signal processing. Signal processing engineers consider speech, image, video, and price of a stock as signals of interest for the given application. The information that they will infer from raw data is different for each application. Financial engineers develop new solutions for financial problems using their knowledge base in signal processing. The goal of financial engineers is to process the harvested financial signal to get meaningful information for the purpose.

Designing investment portfolios have always been at …

System Design And Performance Analysis Of Asymmetrically And Symmetrically Clipped Optical (Asco)-Ofdm For Im/Dd Optical Wireless Communications, Nan Wu

Dissertations

As the quantity of mobile communication devices, such as cellphones, tablets, and laptops, dramatically increase, the demand for high speed wireless service has been growing. Optical wireless communications (OWCs), which offer unlimited transmission bandwidth, have received a lot of attention and been studied in recent decades. They can be an effective alternative to radio frequency communications (RFCs) for indoor high speed data transmission. Intensity modulation direct detection (IM/DD) is a simple way to realize the transmission of optical wireless signals in an indoor environment. Information data streams are modulated into the intensity of optical carriers and transmitted by light emitting …

Novel Algorithms For Fair Bandwidth Sharing On Counter Rotating Rings, Mete Yilmaz

Dissertations

Rings are often preferred technology for networks as ring networks can virtually create fully connected mesh networks efficiently and they are also easy to manage. However, providing fair service to all the stations on the ring is not always easy to achieve.

In order to capitalize on the advantages of ring networks, new buffer insertion techniques, such as Spatial Reuse Protocol (SRP), were introduced in early 2000s. As a result, a new standard known as IEEE 802.17 Resilient Packet Ring was defined in 2004 by the IEEE Resilient Packet Ring (RPR) Working Group. Since then two addenda have been introduced; …

Vector Coprocessor Sharing Techniques For Multicores: Performance And Energy Gains, Spiridon Florin Beldianu

Dissertations

Vector Processors (VPs) created the breakthroughs needed for the emergence of computational science many years ago. All commercial computing architectures on the market today contain some form of vector or SIMD processing.

Many high-performance and embedded applications, often dealing with streams of data, cannot efficiently utilize dedicated vector processors for various reasons: limited percentage of sustained vector code due to substantial flow control; inherent small parallelism or the frequent involvement of operating system tasks; varying vector length across applications or within a single application; data dependencies within short sequences of instructions, a problem further exacerbated without loop unrolling or other …

Energy-Efficient Multi-Criteria Packet Forwarding In Multi-Hop Wireless Networks, Komlan Egoh

Dissertations

Reliable multi-hop packet forwarding is an important requirement for the implementation of realistic large-scale wireless ad-hoc networks. However, packet forwarding methods based on a single criterion, such as the traditional greedy geographic forwarding, are not sufficient in most realistic wireless settings because perfect-reception-within-rangecannot be assumed. Furthermore, methods where the selection of intermediate relaying nodes is performed at the transmitter-side do not adapt well to rapidly changing network environments. Although a few link-aware geographic forwarding schemes have been reported in the literature, the tradeoffs between multiple decision criteria and their impact on network metrics such as throughput, delay and energy …

High-Performance Matrix Multiplication On Intel And Fgpa Platforms, Gang Li

Theses

Matrix multiplication is at the core of high-performance numerical computation. Software methods of accelerating matrix multiplication fall into two categories. One is based on calculation simplification. The other one is based on increasing the memory access efficiency. Also matrix multiplication can be accelerated using vector processors. In this investigation, various matrix multiplication algorithms and the vector-based hardware acceleration method are analyzed and compared in terms of performance and memory requirements. Results are shown for Intel and Xilinx FPGA platforms. They show that when the CPU is fast, Goto's algorithm runs faster than Strassen's algorithm because the data access speed is …

Modeling Next Generation Air Traffic Control System With Petri Net, Hang Wu

Theses

The Federal Aviation Administration (FAA) is one of the largest Air Navigation Service Providers, managing air traffic for more than 15% of the world's airspace. Today's Air Traffic Control (ATC) system cannot meet the growth of the air traffic activities, which brings with more unprecedented delays. At the same time, Air Traffic Controllers are facing higher workload than ever before. The FAA has declared that the existing ATC system will transition to a new system known as “Free Flight”. “Free Flight” will change today's ATC system by giving pilots increased flexibility to choose and modify their routes in real time, …

Energy Scavenging System For Indoor Wireless Sensor Network, David Andrew Crea

Theses

As wireless communication evolves wireless sensors have begun to be integrated into society more and more. As these sensors are used to a greater extent newer and better ways to keep them working optimally have begun to surface. One such method aims to further the sensors energy independence on humans. This technique is known as energy scavenging. The logic behind energy scavenging is to allow the device to have its own reliable source of energy that does not require upkeep, has a long life expectancy, and does not completely rely on an internal power source. The aim of this thesis …

Hardware Support For Real-Time Network Security And Packet Classification Using Field Programmable Gate Arrays, Nitesh Bhicu Guinde

Dissertations

Deep packet inspection and packet classification are the most computationally expensive operations in a Network Intrusion Detection (NID) system. Deep packet inspection involves content matching where the payload of the incoming packets is matched against a set of signatures in the database. Packet classification involves inspection of the packet header fields and is basically a multi-dimensional matching problem. Any matching in software is very slow in comparison to current network speeds. Also, both of these problems need a solution which is scalable and can work at high speeds. Due to the high complexity of these matching problems, only Field-Programmable Gate …

Soft-Error Resilient On-Chip Memory Structures, Shuai Wang

Dissertations

Soft errors induced by energetic particle strikes in on-chip memory structures, such as L1 data/instruction caches and register files, have become an increasing challenge in designing new generation reliable microprocessors. Due to their transient/random nature, soft errors cannot be captured by traditional verification and testing process due to the irrelevancy to the correctness of the logic. This dissertation is thus focusing on the reliability characterization and cost-effective reliable design of on-chip memories against soft errors.

Due to various performance, area/size, and energy constraints in various target systems, many existing unoptimized protection schemes on cache memories may eventually prove significantly inadequate …

On Modeling And Mitigating New Breed Of Dos Attacks, Amey Bhaskar Shevtekar

Dissertations

Denial of Service (DoS) attacks pose serious threats to the Internet, exerting in tremendous impact on our daily lives that are heavily dependent on the good health of the Internet. This dissertation aims to achieve two objectives:1) to model new possibilities of the low rate DoS attacks; 2) to develop effective mitigation mechanisms to counter the threat from low rate DoS attacks.

A new stealthy DDoS attack model referred to as the "quiet" attack is proposed in this dissertation. The attack traffic consists of TCP traffic only. Widely used botnets in today's various attacks and newly introduced network feedback control …

Retransmission Strategies For Moving Networks Over Ricean Fading Channels, Alex Ruiz Lee

Theses

The problem of designing retransmission protocols based on Hybrid Automatic Repeat reQuest (HARQ) for moving networks over Ricean fading channels has been considered. The scenario of interest consists of one receiver traveling at a given speed while connected to a wireless network based on OFDM (e.g., WiMax) through several base stations located along the path. Five different retransmission protocols that combine HARQ with handover between adjacent base stations are considered. Their performance in terms of number of retransmissions per packet via numerical simulations, considering both frequency selective and nonselective channels are presented. The results obtained show the relevant advantage that …

Proactive Methods For Measurement Of Available Bandwidth And Link Capacity, Khondaker Musfakus Salehin

Theses

With the continuous expansion of network infrastructure and deployment of applications sensitive to Quality-of-Service, network measurement plays a major role in both network planning and management. Accurate measurement of various network parameters, e.g., available bandwidth, link capacity, delay, packet loss and jitter, provides a positive impact for effective traffic engineering, Quality-of-Service (QoS) routing, optimization of end-to-end transport performance, and link capacity planning. For network measurement, there exists several proactive estimation tools based on either probe-gap model or probe-rate model that estimate path related attributes. Most of these tools that have been implemented can measure tight-link capacity (smallest available bandwidth) and/or …

Two Factor Authentication And Authorization In Ubiquitous Mobile Computing, Qing Zhu

Theses

Handheld devices, such as mobile phones, PDAs and others, have become an integrated part of our lives. They are perfectly suitable to become the first real-life platforms for mobile computing applications. A lightweight holistic authentication and authorization scheme is presented for this typical wireless scenario. It is shown that either SIM or Kerberos authentication has its limitations. A two-factor authentication method SIM-based Kerberos authentication is developed to implement the Secure Single Sign-on function with LDAP protocol realization for authorization and mobile directory services. Performance analysis and power consumption analyses for this protocol are presented as well. Our results show that …

Kerberos Phone Secure Messenger, Nabeel Al-Saber

Theses

Security is becoming vital in today's open insecure Internet. While popular Internet enabled mobile devices are spreading widely, the security of such platforms is not maturely addressed. This research extends the popular Kerberos authentication protocol to run on mobile phones and builds a novel Kerberos Secure Phone Messenger (KSPM) on top of the protocol. Moreover, the Kerberos network authentication protocol provides user authentication and message privacy with the convenience of secret key cryptography. Such an advantage in mobile phones helps reduce the computational burden and power consumption if compared with public key cryptography. KSPM achieves high standards in terms of …

Route Recovery Schemes For Link And Node Failure And Link Congestion, Ibrahim Takouna

Theses

Link/Node failure occurs frequently causing service disruption in computer networks. Hardware techniques have been developed to protect the network from Link/Node failure. These techniques work in physical layer, therefore their convergence time is very small. On the other hand, many schemes have been proposed to mitigate the failure influence on the network. These schemes work in upper layers such as the network layer. However, hardware solutions faster than other schemes, but they are expensive. Link/Node failure causes all flows which were using the failed link/node are temporarily interrupted till a new path reestablished.

Three recovery algorithms have been proposed that …

Development And Evaluation Of A Simultaneous Multithreading Processor Simulator, Carla Verena S. Nunez

Theses

Modem processors are designed to achieve greater amounts of instruction level parallelism (ILP) and thread level parallelism (TLP). Simultaneous multithreading (SMT) is an architecture that exploits both LLP and TLP. It improves the utilization of the processor resources by allowing multiple independent threads to reside in the pipeline and dynamically scheduling the available resources among the threads.

The first part of this thesis presents the development of a simultaneous multithreading processor simulator. The SMT simulator is derived from SimpleScalar, a superscalar processor simulator widely used in the computer architecture research field. The basic pipeline is expanded to allow multiple threads …