Engineering Commons^™

Toward Automated Detection And Diagnosis Of Mammographic Microcalcifications, Imad Mohammad Zyout

Dissertations

Mammographie diagnosis is the most effective technique to detect breast cancer in its infancy when it is most responsive to treatment. An early and a significant indicator of breast cancer is the presence of clustered microcalcifications (MCs). Mammographie MCs greatly vary in their appearance and shape, and become indistinguishable when surrounded by dense breast tissue. This makes radiologist's interpretation of mammograms a tedious and an error prone task.

Although computer aided diagnosis (CAD) methods are being developed to aid radiologist in detecting and analyzing the malignancy of MCs, existing systems have not achieved a satisfactory performance. The specificity of existing …

An Automated Framework For Defect Detection In Concrete Bridge Decks Using Fractals And Independent Component Analysis, Fadi Abu-Amara

Dissertations

Bridge decks deteriorate over time as a result of deicing salts, freezing-andthawing, and heavy use, resulting in internal defects. According to a 2006 study by the American Society of Civil Engineers, 29% of bridges in the United States are considered structurally deficient or functionally obsolete. Ground penetrating radar (GPR) is a promising non-destructive evaluation technique for assessing subsurface conditions of bridge decks. However, the analysis of GPR scans is typically done manually, where the accuracy of the detection process depends on the technician's trained eye. In this work, a framework is developed to automate the detection, localization, and characterization of …

Pattern Recognition For Fault Detection, Classification, And Localization In Electrical Power Systems, Qais Hashim Alsafasfeh

Dissertations

The longer it takes to identify and repair a fault, the more damage may result in the electrical power system, especially in periods of peak loads, which could lead to the collapse of the system, causing the power outage to extend for a longer period and larger parts of the electrical network. Reducing the outage time and immediate restoration of service can be achieved if the fault type and location are determined in a timely and precise manner.

An integrated algorithm that is based on generating unique signatures from the electric current signal to detect, classify, and localize a fault …

Properties And Device Applications Of Silicon And Silicon-Germanium Nanostructures With Different Dimensions, Han-Yun Chang

Dissertations

Defect-free crystalline Si/SiGe(Ge) nanostructures are demonstrated despite the 4% lattice mismatch between Si and Ge. The lattice mismatch-induced strain is sufficiently relaxed through the designed, cluster morphology, or nanowire (NW) structures. Future device applications of these nano structures require complete understanding of their structural, optical, electrical and thermal properties. This study explores these properties in two-dimensional (2D) Si/Si:B delta-doped multilayers, 2D Si/Si_1-xGe_x planar multilayers, three-dimensional (3D) Si/Si_1-xGe_{x cluster multilayers, one-dimensional (1D) Si NWs and 1D Si/Ge NW heterojunctions (HJs).}

Raman scattering and photoluminescence measurements show that by alternating heavily boron-doped layers with layers of …

Mechanisms For Quality-Of-Service Provisioning In Networks With Extended Services, Zhen Qin

Dissertations

The emerging network traffic with various Quality-of-Service (QoS) requirements creates a demand for QoS service provisioning beyond the best effort service that Internet currently provides. QoS provisioning requires a framework that satisfies users' QoS and cost demand while maximizes benefits for network service providers. It is considered that QoS provisioning involves three issues: a) estimations of the network QoS performance, which can be achieved by performing network measurement; b) dissemination of the measured QoS states throughout the network with states exchanged among different network routers; and c) QoS routing. In this dissertation, these three issues are addressed.

In QoS networks, …

Design Of Adaptive Collective Foraging In Swarm Robotic Systems, Hanyi Dai

Dissertations

Inspired by the collective behavior observed in biological colonies, swarm robotics is a new approach to design a distributed control algorithm in order to coordinate a group of simple robots performing a complex group task. With only limited computation and communication ability of individual robots, one of the challenges in designing such multi-robotic systems is to understand the effect of individual robots behavior on the group performance. This thesis dedicates the research to designing a set of local interaction and adaptation rule for individual robots so that optimized collective foraging performance can be achieved at group level.

The research starts …

Target Localization In Mimo Radar Systems, Hana Godrich

Dissertations

MIMO (Multiple-Input Multiple-Output) radar systems employ multiple antennas to transmit multiple waveforms and engage in joint processing of the received echoes from the target. MIMO radar has been receiving increasing attention in recent years from researchers, practitioners, and funding agencies. Elements of MIMO radar have the ability to transmit diverse waveforms ranging from independent to fully correlated. MIMO radar offers a new paradigm for signal processing research. In this dissertation, target localization accuracy performance, attainable by the use of MIMO radar systems, configured with multiple transmit and receive sensors, widely distributed over an area, are studied. The Cramer-Rao lower bound …

Service Oriented Networking For Multimedia Applications In Broadband Wireless Networks, Ehsan Haghani Dogaheh

Dissertations

Extensive efforts have been focused on deploying broadband wireless networks. Providing mobile users with high speed network connectivity will let them run various multimedia applications on their wireless devices. In order to successfully deploy and operate broadband wireless networks, it is crucial to design efficient methods for supporting various services and applications in broadband wireless networks. Moreover, the existing "access-oriented" networking solutions are not able to fully address all the issues of supporting various applications with different quality of service requirements. Thus, "service-oriented" networking has been recently proposed and has gained much attention.

This dissertation discusses the challenges and possible …

Cooperative Retransmission Protocols In Fading Channels : Issues, Solutions And Applications, Igor Stanojev

Dissertations

Future wireless systems are expected to extensively rely on cooperation between terminals, mimicking MIMO scenarios when terminal dimensions limit implementation of multiple antenna technology. On this line, cooperative retransmission protocols are considered as particularly promising technology due to their opportunistic and flexible exploitation of both spatial and time diversity. In this dissertation, some of the major issues that hinder the practical implementation of this technology are identified and pertaining solutions are proposed and analyzed. Potentials of cooperative and cooperative retransmission protocols for a practical implementation of dynamic spectrum access paradigm are also recognized and investigated. Detailed contributions follow.

While conventionally …

Adaptive Trust And Reputation System As A Security Service In Group Communications, Pitipatana Sakarindr

Dissertations

Group communications has been facilitating many emerging applications which require packet delivery from one or more sender(s) to multiple receivers. Owing to the multicasting and broadcasting nature, group communications are susceptible to various kinds of attacks. Though a number of proposals have been reported to secure group communications, provisioning security in group communications remains a critical and challenging issue.

This work first presents a survey on recent advances in security requirements and services in group communications in wireless and wired networks, and discusses challenges in designing secure group communications in these networks. Effective security services to secure group communications are …

Generalized Discrete Fourier Transform With Non-Linear Phase : Theory And Design, Handan Agirman-Tosun

Dissertations

Constant modulus transforms like discrete Fourier transform (DFT), Walsh transform, and Gold codes have been successfully used over several decades in various engineering applications, including discrete multi-tone (DMT), orthogonal frequency division multiplexing (OFDM) and code division multiple access (CDMA) communications systems. Among these popular transforms, DFT is a linear phase transform and widely used in multicarrier communications due to its performance and fast algorithms. In this thesis, a theoretical framework for Generalized DFT (GDFT) with nonlinear phase exploiting the phase space is developed. It is shown that GDFT offers sizable correlation improvements over DFT, Walsh, and Gold codes. Brute force …

Advanced Classification Of Ofdm And Mimo Signals With Enhanced Second Order Cyclostationarity Detection, Miao Shi

Dissertations

With the emergence of cognitive radio and the introduction of new modulation techniques such as OFDM and MIMO, the problem of Modulation Classification (MC) becomes more challenging and complicated. In the first part of the thesis, we explore the automatic modulation classification to blindly distinguish OFDM from single carrier signals. We use the fourth order cumulants; an approach which in the past has been also applied to classify single carrier signals. A blind OFDM parameter estimation scheme was then followed, which includes the estimation of number of subcarriers, CP length, timing and frequency offset and the oversampling factor for the …

Nano-Scaled Fet Device For Cmos Technology, Prabhat Ranjan Pathak

Dissertations

In this work the 3-D structure of the Accumulation mode (ACM) and Enhance mode (ECM) FinFET was developed by the Taurus-Device Editor. The design of both ACM and ECM FinFET was optimized for high-performance IC applications to meet ITRS specification for I_off current, for 9nm gate length. The design of ACM and ECM FinFET is optimized, analyzed and compared against each other with respect to Darin Induced Barrier Lower (DIBL), Sub-threshold Swing(SS), operation and performance characteristics with varying electrical and physical parameters Silicon thickness (T_si), Source/Drain doping gradient (σ_sd), electrical channel length (L_eff ), …