Engineering Commons^™

Effect Of Annealing On Copper Thin Films:The Classical Size Effect And Agglomeration, Parag Gadkari

Electronic Theses and Dissertations

With continued shrinking of CMOS technology to reduce the gate delay times, an increase in the resistivity of the metal corresponding to the wire dimension is a concern. This phenomenon of increase in resistivity with decreasing dimension of the thin metallic film or interconnect is known as the "classical size effect". Various theories have been postulated to explain the phenomenon of classical size effect; these theories can be broadly classified as resistivity due to scattering arising from surface and grain boundaries. The total resistivity of metals depends on the electron scattering due to impurities, phonons, surfaces, grain boundaries, and other …

Stabilization And Tracking Of The Van Der Pol Oscillator, Xin Zhao

Electronic Theses and Dissertations

In this thesis, the stabilization and tracking problem of the Van der Pol oscillator is studied by using advanced control techniques. First, the linear state feedback and linear adaptive state feedback controllers for the stabilization problem are designed. Then, non-linear state feedback and output feedback controllers are proposed for the tracking problem with known parameters. Finally, a dynamic output feedback controller based on adaptive backstepping technique is introduced for the tracking problem when all parameters of the Van der Pol system are unknown.

Speaker Identification Based On Discriminative Vector Quantization And Data Fusion, Guangyu Zhou

Electronic Theses and Dissertations

Speaker Identification (SI) approaches based on discriminative Vector Quantization (VQ) and data fusion techniques are presented in this dissertation. The SI approaches based on Discriminative VQ (DVQ) proposed in this dissertation are the DVQ for SI (DVQSI), the DVQSI with Unique speech feature vector space segmentation for each speaker pair (DVQSI-U), and the Adaptive DVQSI (ADVQSI) methods. The difference of the probability distributions of the speech feature vector sets from various speakers (or speaker groups) is called the interspeaker variation between speakers (or speaker groups). The interspeaker variation is the measure of template differences between speakers (or speaker groups). All …

Analysis And Design Of Miniaturized Rf Saw Duplexer Package, Hao Dong

Electronic Theses and Dissertations

This dissertation provides a comprehensive methodology for accurate analysis and design of miniaturized radio frequency (RF) surface acoustic wave (SAW) duplexer package. Full-wave analysis based on the three dimensional (3-D) finite element method (FEM) is successfully applied to model the package. The die model is obtained by combining the acoustics and die busbars parasitics models. The acoustics model is obtained using the coupling-of-models (COM) technique. The die busbars, bonding wires and printed circuit board (PCB) are modeled using full-wave analysis. After that, the models of package, die, and bonding wires are assembled together to get the total response. To take …

Preparation And Characterization Of Cigss Solar Cells And Pv Module Data Analysis, Jyoti Shirolikar

Electronic Theses and Dissertations

In this thesis, multiple activities have been carried out in order to improve the process of CIGSS solar cell fabrication on a 4" x 4" substrate. The process of CIGSS solar cell fabrication at FSEC's PV Materials Lab involves a series of steps that were all carried out manually in the past. A LABVIEW program has been written to carry out automated sputter deposition of Mo back contact, CuGa, In metallic precursors on a soda lime glass substrate using a stepper motor control for better uniformity. Further, selenization/ sulfurization of these precursors was carried out using rapid thermal processing (RTP). …

Interconnection, Interface And Instrumentation For Micromachined Chemical Sensors, Naveenkumar Srinivasaiah Palsandram

Electronic Theses and Dissertations

In realizing a portable chemical analysis system, adequate partitioning of a reusable component and a disposable is required. For successful implementation of micromachined sensors in an instrument, reliable methods for interconnection and interface are in great demand between these two major parts. This thesis work investigates interconnection methods of micromachined chip devices, a hybrid fluidic interface system, and measurement circuitry for completing instrumentation. The interconnection method based on micromachining and injection molding techniques was developed and an interconnecting microfluidic package was designed, fabricated and tested. Alternatively, a plug-in type design for a large amount of sample flow was designed and …

Studies Of Liquid Crystal Response Time, Haiying Wang

Electronic Theses and Dissertations

In this dissertation, the response time issue of the liquid crystal (LC) devices is investigated in meeting the challenges for display and photonic applications. The correlation between the LC director response time and the optical response time is derived theoretically and confirmed experimentally. A major contribution of this thesis is that, based on the small angle approximation, we derive rigorous analytical solutions for correlating the LC director response time to its consequent optical response times (both rise and decay) of a vertical-aligned nematic LC cell. This work successfully fills the gap in the literature of LCD switching dynamics. An important …

Super High-Speed Miniaturized Permanent Magnet Synchronous Motor, Liping Zheng

Electronic Theses and Dissertations

This dissertation is concerned with the design of permanent magnet synchronous motors (PMSM) to operate at super-high speed with high efficiency. The designed and fabricated PMSM was successfully tested to run upto 210,000 rpm The designed PMSM has 2000 W shaft output power at 200,000 rpm and at the cryogenic temperature of 77 K. The test results showed the motor to have an efficiency reaching above 92%. This achieved efficiency indicated a significant improvement compared to commercial motors with similar ratings. This dissertation first discusses the basic concept of electrical machines. After that, the modeling of PMSM for dynamic simulation …

Rr Interval Estimation From An Ecg Using A Linear Discrete Kalman Filter, Arun Janapala

Electronic Theses and Dissertations

An electrocardiogram (ECG) is used to monitor the activity of the heart. The human heart beats seventy times on an average per minute. The rate at which a human heart beats can exhibit a periodic variation. This is known as heart rate variability (HRV). Heart rate variability is an important measurement that can predict the survival after a heart attack. Studies have shown that reduced HRV predicts sudden death in patients with Myocardial Infarction (MI). The time interval between each beat is called an RR interval, where the heart rate is given by the reciprocal of the RR interval expressed …

Oceanic Rain Identification Using Multifractal Analysis Of Quikscat Sigma-0, Vasud Ganesh Torsekar

Electronic Theses and Dissertations

The presence of rain over oceans interferes with the measurement of sea surface wind speed and direction from the Sea Winds scatterometer and as a result wind measurements contain biases in rain regions. In past research at the Central Florida Remote Sensing Lab, it has been observed that rain has multi-fractal behavior. In this report we present an algorithm to detect the presence of rain so that rain regions are flagged. The forward and aft views of the horizontal polarization σ0 are used for the extraction of textural information with the help of multi-fractals. A single negated multi-fractal exponent is …

An Evaluation Of Model-Based Predictive Control, Daniel Czarkowski

Theses

This thesis attempts to determine whether advanced control algorithms offer any real benefits to the process industry in terms of optimising single-input single output process units. To establish this, an ideal PID controller, Two Degree of Freedom (2 DOF) PID Controller and the Generalised Predictive Controller (GPC) are compared. A common design philosophy is applied based on optimising performance subject to constraints on robustness. Specifically, three different designs are examined; minimum subject to constraints on the gain and phase margin, minimum lAE subject to constraints on the modulus margin and minimum lAE subject to constraints on the input sensitivity function. …

Characterisation, Modelling And Performance Evaluation Of Cmos Integrated Rf-Mems Multielectrode Tunable Capacitor, Zbigniew Olszewski

Theses

The circuits used in telecommunications are made of two types of components; active integrated circuits that have continuously been improved together with the evolution of the Si technology and off-chip and on-chip passive components. The latter did not profit from much development and now constitute the bottleneck for further integration of RF (Radio Frequency) integrated circuits. MicroElectroMechanical Systems (MEMS) is rapidly emerging as an enabling technology to yield a new generation of high performance components to replace off-chip (not integrated) and on-chip (poor performance) counterparts. The RF components (RF-MEMS) that can be fabricated with MEMS technology are mainly the resonator, …

Automated Control Of Led-Based Illumination Using Image Analysis Metrics, Stephen Mills

Theses

This project discusses a microprocessor controlled illumination system that covers the visible spectrum. It uses multiple discrete wavelength LEDs. Spatial and spectral illumination profiles are achieved by controlling LED currents with an array of voltage controlled current sources. A highly efficient polycarbonate holographic diffuser is used to improve the uniformity of the distribution. System design is underpinned by accurate characterisation and modelling of the LEDs used.

Image analysis techniques are then used to parameterise the recorded scene and to provide a figure of merit for the quality of the illumination. Several functions such as contrast, low/high saturation, average brightness and …

Multispectral Camera Control And High Speed Image Transfer Using Lossless Hardware Compression, Padraig Ryan

Theses

This work provides extensions of a standard D-Cam/Firewire digital camera platform for use within a multispectral imaging setting and includes real-time lossless image compression targeted at the re-configurable environment of an FPGA. The control and image acquisition structures specific to multispectral systems are detailed with respect to an embedded firmware solution, complementary host PC software driver routines, and camera hardware control infrastructures. The augmentation of the standards based implementation is discussed without compromising compliance with underlying specifications. The mandate for image data acquisition includes glue logic to efficiently transmit data via a high-speed communications pipe, IEEE - 1394 in this …

Controller Design And Web-Based Simulation For A Pasteurisation Process, Luis Torres

Theses

The basic PID controller remains the most commonly used automatic feedback control technique in industry. Many tuning techniques exist for this controller and the use of tuning rules remains very popular, both in industry and academia. This thesis is concerned with the practical evaluation of a selected number of PID tuning rules. The rules were to be evaluated on an industrial pilot-scale milk pasteurisation process. However, most of these rules could not be tested on the real plant as the industrial distributed control system was quite inflexible and did not permit many of the more advanced PID structures e.g. two-degree …

Coverage Path Planning And Control For Autonomous Mobile Robots, Mohanakrishnan Balakrishnan

Electronic Theses and Dissertations

Coverage control has many applications such as security patrolling, land mine detectors, and automatic vacuum cleaners. This Thesis presents an analytical approach for generation of control inputs for a non-holonomic mobile robot in coverage control. Neural Network approach is used for complete coverage of a given area in the presence of stationary and dynamic obstacles. A complete coverage algorithm is used to determine the sequence of points. Once the sequences of points are determined a smooth trajectory characterized by fifth order polynomial having second order continuity is generated. And the slope of the curve at each point is calculated from …

New Optimal High Efficiency Dsp-Based Digital Controller Design For Super High-Speed Permanent Magnet Synchronous Motor, Limei Zhao

Electronic Theses and Dissertations

This dissertation investigates digital controller and switch mode power supply design for super high-speed permanent magnet synchronous motors (PMSM). The PMSMs are a key component for the miniaturic cryocooler that is currently under development at the University of Central Florida with support from NASA Kennedy Space Center and the Florida Solar Energy Center. Advanced motor design methods, control strategies, and rapid progress in semiconductor technology enables production of a highly efficient digital controller. However, there are still challenges for such super high-speed controller design because of its stability, high-speed, variable speed operation, and required efficiency over a wide speed range. …

Sonar Signal Enhancement Using Fractional Fourier Transform, Madalina Barbu, Edit J. Kaminsky, Russell E. Trahan

Electrical Engineering Faculty Publications

In this paper we present an approach for signal enhancement of sonar signals. Work reported is based on sonar data collected by the Volume Search Sonar (VSS), as well as VSS synthetic data. The Volume Search Sonar is a beamformed multibeam sonar system with 27 fore and 27 aft beams, covering almost the entire water volume (from above horizontal, through vertical, back to above horizontal). The processing of a data set of measurement in shallow water is performed using the Fractional Fourier Transform algorithm. The proposed technique will allow efficient determination of seafloor bottom characteristics and bottom type using the …

Chirp Slope Keying For Underwater Communications, Edit J. Kaminsky, Lastri Simanjuntak

Electrical Engineering Faculty Publications

This paper presents a novel broadband modulation method for digital underwater communications: Chirp Slope Keying (CSK). In its simplest form, the binary information modulates the slope of a linear chirp, with up-chirps representing ones and down-chirps representing zeros. Performance evaluation in the form of probability of error vs. SNR show that the system performs as expected for AWGN environments and very well for more realistic models for underwater acoustical communications, such as the Raylegih channel with Doppler, delays, phase offset, and multipath.

Blind Phase Recovery In Cross Qam Communication Systems With The Reduced Constellation Eigth-Order Estimator (Rceoe), Kenneth V. Cartwright, Edit J. Kaminsky

Electrical Engineering Faculty Publications

The eighth-order (EOE) phase estimator [4] is modified to work for an eight-symbol symmetrical constellation, so that the large signal-to-noise (SNR) performance is not limited by self-noise. By using only the eight highest energy points of cross- QAM constellations, a reduced constellation eighth-order estimator (RCEOE) is proposed. Computer simulations for 128-QAM show that this new method performs substantially better than the recently introduced APP phase estimator of Wang et al. [8]. However, simulations with 32-QAM show little performance advantage of the RCEOE over the APP estimator, for SNR values normally of interest, whereas for low SNR, the improvement is significant. …

An Optimum Hardware Detector For Constant Envelope Quadrature-Quadrature Phase Shift Keying (Ceq2osk), Kenneth V. Cartwright, Edit J. Kaminsky

Electrical Engineering Faculty Publications

A hardware detector for constant envelope quadrature- quadrature phase-shift keying (CEQ2PSK) is proposed. It uses appropriate hard decisions; yet, it achieves optimum probability of bit error performance, unlike the suboptimum detector of Saha and Birdsall. This optimum performance is verified through Monte Carlo computer simulations. Additionally, a more correct expression is given for the probability of bit error performance for CEQ2PSK, which gives the gain over nonconstant Q2PSK as 1.44 dB, rather than the previously published value of 1.76 dB.

Asymptotic Performance Of The Pth Power-Law Phase Estimator, Kenneth V. Cartwright, Edit J. Kaminsky

Electrical Engineering Faculty Publications

An expression for the true variance of the Pth powerlaw phase estimator, as the number of samples approaches infinity, is given. This expression is an extension to the linear approximation of Moeneclaey and de Jonghe [1] which is known to be inadequate in some practical systems. Our new expression covers general 2π/P-rotationally symmetric constellations that include those of PAM, QAM, PSK, Star M-QAM, MR-DPSK, and others. This expression also generalizes the known expressions for QAM and PSK. Additionally, our expression reduces to the Cramer-Rao bound given by Steendam and Moeneclaey [9], as SNR goes to zero. Monte Carlo simulations provide …

Solar-Based Single-Stage High-Efficiency Grid-Connected Inverter, Feng Tian

Electronic Theses and Dissertations

Renewable energy source plays an important role in the energy cogeneration and distribution. Traditional solar-based inverter system is two stages in cascaded, which has a simpler controller but low efficiency. A new solar-based single-stage grid-connected inverter system can achieve higher efficiency by reducing the power semiconductor switching loss and output stable and synchronized sinusoid current into the utility grid. Controlled by the digital signal processor, the inverter can also draw maximum power from the solar array, thereby maximizing the utilization of the solar array. In Chapter 1, a comparison between the traditional two-stage inverter and the single-stage inverter is made. …

Solution Of Electromagnetic Scattering Parameters And Radiation Patterns Of Arbitrary Body Of Revolution Radiators, Wendell Brokaw

Electronic Theses and Dissertations

A novel full wave analysis method to determine the scattering parameters and the radiation field intensities of arbitrary Body of Revolution (BOR) radiators consisting of impenetrable media is explored through derived components of modal analysis and the method of moments (MoM). Modal excitation is utilized to excite the structural feed; allowing for a more accurate measure of the scattering parameters of the total structure as opposed to the use of external excitation sources. The derivation of the mode matching method introduces a novel approach to achieving a frequency independent coupling matrix that will reduce the computational requirements for iterations utilized …

Multi-Channel Audio Time-Scale Modification, David Dorran, Robert Lawlor, Eugene Coyle

Conference papers

Phase vecoder based approaches to audio time-scale modification introduce a reverberant artefact into the time scaled output. Recent techniques have been developed to reduce the presence of this artefact; however, these techniques have the effect of introducing additional issues relating to their application to multi-channel recordings. This paper addresses these issues by collectively analysing all channels prior to time-scaling each individual channel.

Modeling And Simulation Of Long Term Degradation And Lifetime Of Deep-Submicron Mos Device And Circuit, Zhi Cui

Electronic Theses and Dissertations

Long-term hot-carrier induced degradation of MOS devices has become more severe as the device size continues to scale down to submicron range. In our work, a simple yet effective method has been developed to provide the degradation laws with a better predictability. The method can be easily augmented into any of the existing degradation laws without requiring additional algorithm. With more accurate extrapolation method, we present a direct and accurate approach to modeling empirically the 0.18-ìm MOS reliability, which can predict the MOS lifetime as a function of drain voltage and channel length. With the further study on physical mechanism …

Microbubble-Based Model Analysis Of Liquid Breakdown Initiation By A Submicrosecond Pulse, J. Qian, R. P. Joshi, K. H. Schoenbach, J. Dickens, A. Neuber, M. Butcher, M. Cevallos, H. Krompholz, E. Schamiloglu, J. Gaudet

Electrical & Computer Engineering Faculty Publications

An electrical breakdown model for liquids in response to a submicrosecond(∼100ns) voltage pulse is presented, and quantitative evaluations carried out. It is proposed that breakdown is initiated by field emission at the interface of pre-existing microbubbles. Impact ionization within the microbubble gas then contributes to plasma development, with cathode injection having a delayed and secondary role. Continuous field emission at the streamer tip contributes to filament growth and propagation. This model can adequately explain almost all of the experimentally observed features, including dendritic structures and fluctuations in the prebreakdown current. Two-dimensional, time-dependent simulations have been carried out based on a …

An Explicit Mapping Between The Frequency Domain And The Time Domain Representations Of Nonlinear Systems, Marissa Condon, Rossen Ivanov

Articles

Explicit expressions are presented that describe the input-output behaviour of a nonlinear system in both the frequency and the time domain. The expressions are based on a set of coefficients that do not depend on the input to the system and are universal for a given system. The anharmonic oscillator is chosen as an example and is discussed for different choices of its physical parameters. It is shown that the typical approach for the determination of the Volterra Series representation is not valid for the important case when the nonlinear system exhibits oscillatory behaviour and the input has a pole …

Energy Meter Reading And Tampering Protection Through Powerline Communication Channel, S Naiman

Tanzania Journal of Engineering and Technology (TJET)

POwer utility companies have suffered revenue losses due to uncollected bills and energy tampering for many years. The use of powerline communication to overcome the problems has been proposed. This needs tampering detection and transceivers capable of communicating data through poww•line channel. This paper identifies different methods Of tampering, presents simulated results for tampering detection scheme and proposes a Direct Sequence Spread Spectrum (DSSS) wilh Binary Phase Shift Keying (BPSK) transceiver design for energy metering as a solution to the problem. The choice of DSSS-BPSK modulation scheme is based on its robustness and its ability to spread signal inro wide …

Short-Term Scheduling Of A Hydro-Thermal System Using Linear Programming Technique, A Kyaruzi

Tanzania Journal of Engineering and Technology (TJET)

The paper discusses the short term scheduling of Hydrothermal for Tanzania Electricity Supply Company (TANESCO) Power System. The problem is to determine on hourly interval the Hydro and Thermal generation. The scheduling keeps balance between production and consumption in a reliable and economical way during the study period. Linear programming (LP) mathematical model using MATL4B has been developed. The constraints are hydrological balance, thermal power plants limitations and load requirements. The result from LP solution gave low operation cost. Generation was mainly from hydro and all reservoirs elevation was high at the end ofplanning period.