Electrical and Electronics Commons^™

Modeling The Controlled Delivery Power Grid, Vinit Madhukar Sahasrabudhe

Theses

Competitive energy markets, stricter regulation, and the integration of distributed renewable energy sources are forcing companies to reengineer energy production and distribution. The Controlled Delivery Power Grid is proposed as a novel approach to transport energy from generators to consumers. In this approach, energy distribution is performed in an asynchronous and distributed fashion. Much like the Internet, energy is delivered as addressable packets, which allow a controlled delivery of energy.

As a proof-of-concept of the controllable delivery grid, two experimental test beds, one with integrated energy storage and another with no energy storage, were designed and built to evaluate the …

Hollow Cathode Sputtering System - Installation, Operation And Theoretical Background, Sebastian Falk

Theses

The objective of this work was to assemble, install and operate a hollow cathode sputtering system (HCSS). Therefore a complex vacuum system was built to create the right sputtering environment. The purpose of the HCSS is to develop advanced thin conducting oxides (TCOs) as well as high resistivity transparent (HRT) layers which are used for thin film photovoltaic technology, particularly cadmium telluride based and copper indium gallium selenide based solar cells.

A theoretical background of the thin film technology and a comparison of different deposition methods in regards to the sputtering process is provided. Thereby, an in-depth investigation of zinc …

Review Of Steganalysis Of Digital Images, Xinlei Pan

Theses

Steganography is the science and art of embedding hidden messages into cover multimedia such as text, image, audio and video. Steganalysis is the counterpart of steganography, which wants to identify if there is data hidden inside a digital medium. In this study, some specific steganographic schemes such as HUGO and LSB are studied and the steganalytic schemes developed to steganalyze the hidden message are studied. Furthermore, some new approaches such as deep learning and game theory, which have seldom been utilized in steganalysis before, are studied. In the rest of thesis study some steganalytic schemes using textural features including the …

Petri Net Models Of Microgrids With Distributed Generators, Xiaoyu Lu

Theses

This thesis introduces some basic concepts and control methods about a microgrid. Then, two hot issues are investigated. One is how to control multiple distributed generators; and another is how to model both discrete event and continuous behaviors of a microgrid. To address these two issues, this thesis work applies Petri nets to both modeling and control of a microgrid. Ordinary Petri nets, hybrid Petri nets, and finite capacity Petri nets, are introduced with their examples targeted at modeling the behavior of a microgrid. Coordination control of multiple distributed generators based on a Petri net model is proposed. Compared with …

Computer Aided Analysis Of Skin Lesions, Sukanya Panja

Theses

Effective screening to detect the skin cancer accurately in the early stage is essential for reducing the mortality of skin cancer. Surface features, such as texture and pigmentation area from the surface, epi-illumination images of the skin lesions have been well correlated to detect skin cancer. An increase in the lesion's subsurface blood volume has been correlated to early diagnosis of malignant melanoma. A method for estimating the optimal features is obtained. The optimal features help in accurately classify the skin lesion in various grades. To make the process faster these optimal features are clustered. The optimal clusters are obtained …

An Embedded System Supporting Dynamic Partial Reconfiguration Of Hardware Resources For Morphological Image Processing, Gyana Ranjan Sahu

Theses

Processors for high-performance computing applications are generally designed with a focus on high clock rates, parallelism of operations and high communication bandwidth, often at the expense of large power consumption. However, the emphasis of many embedded systems and untethered devices is on minimal hardware requirements and reduced power consumption. With the incessant growth of computational needs for embedded applications, which contradict chip power and area needs, the burden is put on the hardware designers to come up with designs that optimize power and area requirements.

This thesis investigates the efficient design of an embedded system for morphological image processing applications …

An Adaptive Physical- And Link Layer For Narrowband Mobile Ad-Hoc Networks, Mathias Dehm

Theses

Search and Rescue (SAR) missions require robust ad-hoc networks especially in situations where existing wired or cellular networks have been damaged or are not available. Here, a promising SAR communications technology is a Mobile Ad-hoc Networks (MANETs). However, development of systems is challenging due to bandwidth constraints, various application services, high mobility and harsh environments leading to unstable wireless connections.

Throughout this thesis, a prototype of a physical- and link layer is developed which satisfies the criteria for communication services in SAR missions.

This work includes three major contributions:

The first contribution is a single-carrier narrowband physical layer. The transmission …

Gaussian Beam Scattering From A Deterministic Rough Metal Surface, Qi Wang

Theses

A full-wave theory of plane wave scattering from rough surfaces called the Correction Current (CC) method was recently developed for the two-dimensional scatter problem that have a one-dimensional roughness profile. The method involves a primary field and radiation modes that are plane-wave-type fields that satisfy the boundary conditions at the rough surface. These fields do not satisfy Maxwell's source free equations, but they are forced to satisfy Maxwell's equations with distributed sources upon the introduction of fictitious volume currents distributions which correct for the field errors. Additionally, current sheet distributions are introduced which generate a radiation modal field that satisfies …

Model Predictive Control Of Timed Continuous Petri Nets, Huaiyu Zhan

Theses

This thesis addresses the optimal control problem of timed continuous Petri nets. The theory of Model Predictive Control (MPC) is first discussed. Then continuous Petri nets (PN) are introduced as a powerful tool for modelling, simulation and analysis of discrete event/continuous systems. Their useful capabilities are studied. Finally, a macroscopic model based on PN as a tool for designing control laws that improve the behavior of traffic systems is given. The goal is to find an approach that minimizes the total delay of cars in an intersection by computing the switching sequence of the traffic lights. The simulation results show …

Service And Communication Management In Cooperative Vehicular Networks, Olivia Brickley

Theses

The concept of Intelligent Transportation Systems (ITS) presents new R&D challenges for the transportation and ICT sectors and is currently receiving considerable interest from the research community. The primary objective of ITS is the creation of advanced road traffic systems for improved traffic safety, efficiency, and travelling comfort. Basic vehicle and roadside infrastructure collaboration allows for an increase in efficiency and safety and acts as the foundation for an extensive service set to achieve these ITS goals. Applications such as journey planning, automatic tolling and emergency warnings, among others, are envisaged in a system which can potentially reform modern transportation. …

A Novel Waveform For Emergency Services Mobile Ad-Hoc Networks : The Link Layer Perspective, Sebastian Helmle

Theses

Existing wireless communication systems of emergency services mainly enable ordinary unicast or broadcast voice communications. The increasing demand for data services such as messaging, file transfer, maps, etc requires those long-range communication systems to provide higher data rates while maintaining robustness against link failures. In this thesis, various aspects of a link layer design specifically for narrowband mobile ad-hoc networks (MANETs) that are targeted at emergency services are investigated.

The major aspect of this thesis is the optimisation of a time division multiple access (TDMA) design considering both efficient and reliable multicast resource reservation. An approach to mathematically describe a …

A New Algorithm For Piecewise Affine System Identification And Its Application To A Mems Switch, Niel Canty

Theses

Over the past ten years, hybrid systems, and piecewise affine (PWA) systems in particular have been viewed as viable option for modelling nonlinear systems. Many methods have been developed to cater for the identification of a PWA model from input/output data. This thesis focuses on the clustering based identification approach. This method uses a Least Squares (LS) identification algorithm which, in this thesis, is shown to perform poorly in practice. The clustering based algorithm is also limited by the number of initialisation parameters that need to be chosen. These parameters have a significant influence on the resulting PWA model accuracy, …

Location Management And Hybrid Geo-Routing For Urban Vehicular Networks, Aisling O'Driscoll

Theses

In recent years the motivation for comfort applications e.g. infotainment, file exchange and vehicle to vehicle (V2V) multiplayer gaming amongst others, has emerged as an active area of vehicular communications and network research. The success of such applications relies on the ability of a geo-routing protocol to deliver communication packets in a frequently disconnected communication environment. To do this, the location of the destination vehicle must first be determined and secondly, must reliably deliver the packet from source to destination. To determine the location of a target vehicle towards which packets can be forwarded, geo-routing algorithms utilise a location service …

Detection Of Video Frame Insertion Based On Constraint Of Human Visual Perception, Lu Zheng

Theses

Recently, due to availability of inexpensive and easily-operable multimedia tools, digital multimedia technology has experienced drastic advancements. At the same time, video forgery becomes much easier and makes more difficult to validate the video content. Consequently, the origin and integrity of video can no longer be taken for granted. A methodology is developed that is capable of detecting the video frame insertion based on the constraint of human visual perception. The main idea is based on the so-called differential sensitivity. That is, that the variation of brightness of neighboring video frames has some constraint. First, the video sequence is partitioned …

Model Predictive Control For Building Temperature Regulation, Weiqiang Dong

Theses

With the rapid increase in human consumption of energy, global warming is becoming an urgent problem. According to the past research, a significant part of greenhouse gas release and electricity consumption has been connected to buildings. Heating systems are the major contributor to high energy consumption of buildings. Better methods for decreasing energy consumption of buildings should be proposed and applied.

Model predictive control is widely used in building temperature regulation. Each model predictive control has its advantage. Through the comparison of several methods, this thesis discusses their respective features. The combination of a Matlab-based modeling system CVX and model …

Research On Mppt Methods For Photovoltaic System Based On Microgrid, Jingchu Ji

Theses

This thesis introduces some basic concepts about a microgrid. Then it discusses the structure of photovoltaic system (PVS) which contains a solar panel and simplified PV models. Next, it discusses and compares different methods for Maximum Power Point Tracking (MPPT) with PVS. It presents three types of DC-DC converters -- Buck, Boost and Buck-Boost converter. This work proposes to apply a DC-DC converter of Buck-Boost type to make PVS controllable because this type of converter has the largest range for operational region so that it can get the best result on MPPT. Finally, this thesis presents a kind of new …

Non-Uniform Transmission Lines For Ultra Wideband: Design Optimisation And Interfacing To Antennas And Loads, Prasanth Moolakuzhy Narayanan

Theses

This thesis presents the electrical characterization of ultra-wideband non- uniform transmission lines (UWB NUTLs). Non-uniform transmission lines have been identified as a successful device for ultra-wideband pulse shaping, which can be designed to generate complex and arbitrary pulse shapes as an impulse response. The performance of a range of UWB NUTLs, with different substrate materials and load impedances, has been characterised. In addition, the possibility of interfacing NUTL with antennas and the filtering effect of antennas has been investigated. To characterise the NUTLs, knowledge of current literature related to NUTL designs is required. A detailed review of the literature published …

Gpu Implementation Of Block Transforms, Boyan Zhang

Theses

Traditionally, intensive floating-point computational ability of Graphics Processing Units (GPUs) has been mainly limited for rendering and visualization application by architecture and programming model. However, with increasing programmability and architecture progress, GPUs inherent massively parallel computational ability have become an essential part of today's mainstream general purpose (non-graphical) high performance computing system. It has been widely reported that adapted GPU-based algorithms outperform significantly their CPU counterpart.

The focus of the thesis is to utilize NVIDIA CUDA GPUs to implement orthogonal transforms such as signal dependent Karhunen-Loeve Transform and signal independent Discrete Cosine Transform. GPU architecture and programming model are examined. …

Three-Dimensional Magnetic Field Sensor In Ibm 0.18Μm Cmos Technology, Gang Wang

Theses

This work presents a compact three-dimensional Magnetic Field Sensor (MFS) designed in standard Complementary Metal-Oxide-Semiconductor (CMOS) technology. A circular Vertical Hall Device (VHD) for horizontal magnetic field detection and a split- drain Horizontal Hall Device (HHD) for the vertical magnetic field detection are integrated to implement the three-dimensional M FS. This merged design has the advantage of smaller area and lower power consumption. The sensitivity of the vertical hall device (ring-shaped magneto-resistor) and the horizontal hall device (Split-Drain Magnetic Field-Effect Transistor (SD-MAGFET)) is estimated as 0.11V/T and 2.88V/T respectively. The vertical direction of the magnetic field detection demonstrates a higher …

Moxon Based Rfid Tag Reader And Gps Antenna, Haojiong Liu

Theses

Modern communication applications at UHF frequencies require antennas with wide band, high forward gain, low backward radiation, high cross-polarization, small size and low manufacture cost. The Moxon antenna based on a two element Yagi-Uda antenna over the ground reflector is one of the most favorite antennas for HAM operators which can produce outstanding front to back ratio of radiated power, good match over the desired band and relatively low elevation height.

A sequence of topologies has been proposed from a single vertical element to two vertical elements of the Moxon arms, until the lately patented Broadband Circularly Polarized Moxon Based …

Analysis And Mitigation Of Carrier Frequency Offset For Uplink Of Ofdma, Abhishek R. Panchal

Theses

Orthogonal Frequency Division Multiplexing (OFDM) is being used in many wireless standards because of its immunity to multipath fading, high spectral efficiency and simple implementation, making it suitable for high data rate multimedia wireless applications. One of the significant drawbacks of the OFDM is its sensitivity to Carrier Frequency Offset (CFO). CFO causes Inter Carrier Interference (ICI) between subcarriers and Multiple User Interference (MUI) at Uplink between different users. ICI and MUI at uplink cause significant degradation in the performance of the receiver, therefore, to improve the receiver performance up to acceptable level, compensation of the CFO becomes necessary.

In …

Dynamic Friction: Measurement And Results, Yanal Jij

Theses

Friction has been known as a phenomenon since Leonardo da Vinci era. From that time and through the last four centuries, scientists tried to understand this phenomenon in an effort to overcome its undesired side effects which include energy loss, parts wearing, and errors in control systems. Much has been achieved in studying friction and many experiments have been conducted in this field. These experiments resulted in a mounting evidence that friction is a dynamic phenomenon.

This thesis presents an apparatus that measures dynamic friction in linear motion and the results obtained using this apparatus. The apparatus consists of a …

Single-Carrier Frequency Domain Equalization Using Subband Decomposition For Optical Wireless Communications, Di Mu

Theses

Optical wireless communication is intended to be applied into indoor and visual distance high-rate data transmission, which is complementary to radio frequency communications. There are specific problems and requirements in optical wireless communications compared with radio frequency communications. Single-carrier frequency domain equalization (SCFDE) is a transmission scheme which has been considered as an alternative of orthogonal frequency-division multiplexing (OFDM), because it has most of the advantages of OFDM and avoids the problems of OFDM. Subband decomposition is a multi-resolution signal analysis and synthesis method, using quadrature mirror filter (QMF) bank to convert time-domain signal to frequency-domain subbands. As a time-to-frequency …

A Distributed Model Predictive Control For Multi-Agent Multi-Rate Systems, Samira Roshany-Yamchi

Theses

In this thesis, a new method is proposed to control multi-agent multi-rate systems with linear dynamics that are coupled via inputs and states. These systems are multi-rate in the sense that either output measurements or input updates are not available at certain sampling. Such systems can arise when the number of sensors is less than the number of variables to be controlled or when measurements of outputs cannot be completed simultaneously because of applicational limitations. The multi-rate nature gives rise to lack of information which will cause uncertainty in the system's performance.

The proposal is to control such systems with …

A Service Provisioning Architecture For Next Generation Wireless Sensor Networks - The Wsn Cloud, Muhammad Sohaib Aslam

Theses

The relentless demand for pervasive computing in our everyday lives has led to and will continue to drive the roll out of large scale embedded systems in the form of Wireless Sensor Networks or WSNs in our environment. This in turn drives the need for reusable, flexible and manageable WSN infrastructures. To simplify system operation and maintenance as well as to reduce costs, WSNs must become an infrastructure that is capable of providing services to multiple end users concurrently rather than having to roll out individual infrastructures for specific purposes as is typical nowadays. This thesis presents the concept of …

Voltage Rise Mitigation In A Weak Distribution Network Due To The Impact Of Distributed Generation, Donal Caples

Theses

There are numerous aspects of a distribution network that must be studied in order to determine the maximum size of distributed generation that can be accommodated on the distribution network before supply standards are breached. Voltage rise is one of the main aspects of concern when connecting a distributed generator to a distribution network and this thesis develops the understanding of this phenomenon and concludes with a real life study.

Mathematical and computer simulation software examples within this thesis demonstrate how voltage rise can be reduced to the maximum allowable limit, a major concern if the capacity of a distributed …

Theoretical And Experimental Analysis Of Mems Ohmic Switch Design And Control For Reliability Improvement, Cuong Do

Theses

MEMS devices are micromechanical components fabricated using semiconductor fabrication technologies. With advanced functionalities and miniaturization, MEMS devices are being employed in a wide variety of applications, especially in mobile networks. The MEMS ohmic switch is one of the most promising MEMS devices and has the same principle of a mechanical moving switch to manipulate an electrical signal. Due to the existence of mechanical movement, and its compactness, reliability issues have been observed as the main barrier to commercialisation.

This thesis addresses the key issue of reliability in the rapidly expanding area of MEMS. In particular, MEMS ohmic switches are considered. …

A Traffic Metering And Marking Technique For Fair Bandwidth Allocation In High Speed Networks, Mary Looney

Theses

The deployment of Quality of Service (QoS) in high speed networks is vital to successful application delivery, especially those that are data-intensive. Continuous efforts have been made to develop infrastructures for enhancing QoS capabilities to manage available bandwidth through the use of traffic conditioners. However, research shows that these techniques distribute bandwidth in an unfair manner. This thesis addresses the failings of traffic conditioning techniques for bandwidth QoS provisioning. Traffic conditioners are comprised of two components, a traffic meter that is responsible for measuring transient characteristics of a traffic stream through a rate estimation technique and a traffic marker that …

Wireless Sensor Networks: Empowering Reliable, Realtime & Resource Efficient Communication For Cyber-Physical Applications, Jasvinder Singh

Theses

Since their inception, Wireless Sensor Networks (WSNs) have been successfully employed as low-rate data gathering networks in numerous monitoring applications. Recently, a new domain of WSNs applications, known as Cyber-Physical Systems (CPS) has started attracting significant attention world-wide. In these applications, monitoring only the state of the physical system (process or environment) is not sufficient, the system must respond to the sensed events/data within certain time constraints by performing actions upon the physical entity. It is expected that in approaching years, WSNs will be integrated in a myriad of CPS applications, for example high confidence medical systems, assisted living, traffic …

Development Of A Vibration-Powered Impact Recorder, William Contreras

Theses

Currently, the U.S. Army stores a great deal of equipment for long periods of time. Often, this equipment is subjected to damaging vibrations. Given this, the army wants to be able to monitor the vibrations that are undergone by this equipment. Here, a battery-powered monitoring device would be undesirable because its batteries would need to be replaced. To solve this problem, an energy harvesting, vibration monitoring device has been developed. The device, which is known as a vibration-powered impact recorder (VPIR for short), uses a piezoelectric transducer to power a microcontroller, which uses the power to count the number of …