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Full-Text Articles in Electrical and Computer Engineering

3d Interconnects For Die And Wafer Stacks, Rachita Dewan Aug 2006

3d Interconnects For Die And Wafer Stacks, Rachita Dewan

Electrical Engineering Theses - Archive

3D integration results from the ever demanding trend towards smaller and lower-profile, lighter and lower cost packaged devices requires further package miniaturization. With the present System-on-chip (SOC) technology reaching its limitation in terms of functionality and cost, effort are being concentrated on exploring the third dimension, i.e. 3D integration. It provides a volumetric packaging solution for higher integration and performance and results in size and weight reduction. Approaches to achieve 3D integration are die and wafer stacking. A key technology to realize the potential of stacking is implementation of vertical electrical interconnects between die and wafer stacks. This thesis discusses …


The Design And Analysis Of Optical Scanners For Optical Coherence Tomography, Naresh Dhaubanjar Aug 2006

The Design And Analysis Of Optical Scanners For Optical Coherence Tomography, Naresh Dhaubanjar

Electrical Engineering Theses - Archive

A miniature fiber optic scanner capable of two-dimensional scanning for medical imaging is designed and developed. The scanner is actuated externally using an electromagnet. Nickel gel, a soft ferromagnetic material, is coated on the optical fiber. The performance of the scanner is characterized. Finite element analysis is performed to validate the theoretical and experimental results. A design and analysis of a cantilever type electrostatic zipping actuator and a bidirectional vertical thermal actuator are presented. The actuation principle, lumped modeling analysis, experimental results, and finite element analysis of both actuators are presented. The actuators are characterized statically and dynamically using the …


Modeling And Performance Evaluation Of A Power Electronic-Based Controlled Fuel Cell System, Yashar Ehsan Kenarangui Aug 2006

Modeling And Performance Evaluation Of A Power Electronic-Based Controlled Fuel Cell System, Yashar Ehsan Kenarangui

Electrical Engineering Theses - Archive

In fuel cell applications, design of an appropriate controller and selection of an Ultra-Capacitor require a suitable model of fuel-cell-systems that can adequately represent the significant characteristics of the system. Such a model, using lumped circuit elements, was developed in this thesis via a simple method without requiring fuel cell design parameters. To validate the model, simulation results from the model were compared against the results from experimental setups and satisfactory results were obtained. Later, this model was used in order to design a controller that meets the control objectives, namely, regulation of output voltage and attenuation of load current …


Analysis Of Electromagnetic Field In A Switched Reluctance Machine From An Energy Conversion Perspective, Wei Jiang Jul 2006

Analysis Of Electromagnetic Field In A Switched Reluctance Machine From An Energy Conversion Perspective, Wei Jiang

Electrical Engineering Theses - Archive

With the recent advancement in power electronics and digital signal processors, switched reluctance machine (SRM) attracts more attention in high speed and harsh environment applications due to its rugged and robust structure. Despite considerable progress in the development of power electronics based control of the SRM, relatively small changes in the magnetic design has been observed. A physically insightful analysis of the electromechanical energy conversion process, origins and spatial distribution of electromagnetic field quantities at a microscopic level can shed light on the process of SRM design, which in turn could create new opportunities for substantial improvement of SRM performance …


An Emission Model For Lunar Regolith Surfaces Based On Matrix Doubling Method, Darshan Shrestha Jul 2006

An Emission Model For Lunar Regolith Surfaces Based On Matrix Doubling Method, Darshan Shrestha

Electrical Engineering Theses - Archive

An emission model based on Matrix Doubling Method is implemented for the calculation of emission signatures from the lunar regolith surfaces. The matrix doubling method is used to solve the radiative transfer equations which encompass the volume and surface scattering properties of the medium. The layer and surface are characterized by their corresponding phase matrices which contain adequate information on how the amplitude, phase and polarization of the incident Stokes vector change on being incident in that medium. Emissivity signatures are calculated by solving the transfer equations using matrix doubling method and taking these phase matrices as "boundary conditions". The …


Fpga Prototyping For Fast And Efficient Verification Of Asic H.264 Decoder, Basavaraj Mudigoudar May 2006

Fpga Prototyping For Fast And Efficient Verification Of Asic H.264 Decoder, Basavaraj Mudigoudar

Electrical Engineering Theses - Archive

To improve compression efficiency, recent video compression standards such as H.264 use complex algorithms and various modes that demand more computational power. Consumer electronics industry requires a low power, compact and cost-effective implementation of video codec for most of the products. ASIC implementation of these video codecs is a logical choice to meet these requirements. Functional verification of an ASIC implementation consumes a major part of design cycle time and lot of resources. Because of large design, various modes and options, functional verification of an ASIC H.264 video codec is a challenging, resource intensive and time consuming process. In this …


Simulation And Characterization Of Znse/Bete Resonant Tunneling Diode On Silicon, Moshe Davis May 2006

Simulation And Characterization Of Znse/Bete Resonant Tunneling Diode On Silicon, Moshe Davis

Electrical Engineering Theses - Archive

ZnSe/BeTe resonant tunneling diodes were grown on silicon with a ZnxBe1-xTe buffer layer using MBE (Molecular Beam epitaxy).These devices were processed and characterized. The devices showed multiple NDR (negative differential resistance) regions at room temperature with PVR (Peak to valley ratios) between 1.01 to 1.23. Variations to the structure were made in growth and their corresponding current-voltage characteristics were studied. The ZnSe/BeTe resonant tunneling diode showed asymmetrical current voltage characteristics for positive and negative biases. The sources of asymmetry were investigated during fabrication and with the help of simulations. The Al/ZnSe contact was confirmed to be ohmic contact when the …


Real-Time Data Monitoring And Manipulation For Wireless Sensor Networks, Sankar Bhanu Gorthi May 2006

Real-Time Data Monitoring And Manipulation For Wireless Sensor Networks, Sankar Bhanu Gorthi

Electrical Engineering Theses - Archive

The growth of Wireless Sensor Network research has brought about the need for tools to help developers rapidly develop applications for various platforms. In the pursuit of these capabilities, this work deals with the design of a graphical approach to development of Wireless Sensor Network applications for implementation in the LabVIEW Graphical Development Environment. The work done also covers the implementation and development of the Sound and Vibration Toolkit for LabVIEW. The implementation of these tools in developing a novel test-bed at the Distributed Intelligence and Automation Laboratory at the ARRI at UT Arlington is also shown. This work is …


Structural Similarity Based Image Quality Assessment: Pooling Strategies And Applications To Image Compression And Digit Recognition, Xinli Shang May 2006

Structural Similarity Based Image Quality Assessment: Pooling Strategies And Applications To Image Compression And Digit Recognition, Xinli Shang

Electrical Engineering Theses - Archive

This thesis studies a recently proposed perceptual image similarity measure: the structural similarity (SSIM) index. Although still in its early stage, the SSIM index has demonstrated superior performance in a large number of tests as compared to the currently most widely used image distortion/quality measures, the mean squared error (MSE) and the peak signal-to-noise-ratio (PSNR). This motivates us to further investigate the SSIM method and extend it to other image processing and pattern recognition applications. Specifically, three topics have been studied in this thesis: spatial pooling strategies for perceptual image quality assessment, structural similarity-guided perceptual image compression, and handwritten digit …


Design And Hardware Implementation Of A Soft-Switched Converter For Fuel Cell Applications, Shiju Wang May 2006

Design And Hardware Implementation Of A Soft-Switched Converter For Fuel Cell Applications, Shiju Wang

Electrical Engineering Theses - Archive

The focus of this thesis is to design a DC-DC quasi-soft switched boost converter suitable for fuel cell applications. Study of electrical output characteristics of fuel cells was necessary for this purpose. A number of experiments were conducted to study the steady-state and transient response of fuel cell system under various load dynamics. The results of these findings were necessary for the next phase of the project which was to design a reliable and high-performance regulated DC-DC converter. The design goals were realized with a soft-switching boost converter (implementation of zero voltage switching (ZVS) and zero current switching (ZCS) schemes) …


Design Of An Enhanced Translinear Variable Floating Resistor And Its Application In A Vga, Nithya Jagannathan May 2006

Design Of An Enhanced Translinear Variable Floating Resistor And Its Application In A Vga, Nithya Jagannathan

Electrical Engineering Theses - Archive

An improved current controlled floating resistor is designed based on translinear loops for application in a Variable Gain Amplifier (VGA). This work compares the use of two different devices and evaluates the difference based on the model parameters and circuit performance. The different architectures employed clearly demarcate the performance variations. The translinear variable resistor exhibits a dynamic range greater than 60 mV. The resistance value lies in the range of 3 K? to few Ohms. A Current Feedback Operational Amplifier (CFOA) is also designed to have an f -3dB of 250 MHz. The CFOA together with the variable resistor in …


A Physics Based Multi-Resolution Technique For Extraction Of Finite Duration Time Responses In Radar Images, Nancy Lanett May 2006

A Physics Based Multi-Resolution Technique For Extraction Of Finite Duration Time Responses In Radar Images, Nancy Lanett

Electrical Engineering Theses - Archive

This paper presents a wavelet multi-resolution technique for examination of scattering phenomena in radar images. Through multi-resolution frequency domain analysis, range gating is implemented for extraction of wave medium interaction phenomena. To analyze the data, a sliding range gate is implemented by applying a phase shift to the spectral domain far field data prior to wavelet analysis. A method for efficient removal of window effects, which occur due to the finite nature of the data, is demonstrated through reconstruction of the decomposed waveform following removal of the lowest resolution. A correlation of the physical meaning of the multi-resolution data to …


Design Of A Cmos Vco And Frequency Divider For 5 Ghz Applications, Prithvi Shylendra May 2006

Design Of A Cmos Vco And Frequency Divider For 5 Ghz Applications, Prithvi Shylendra

Electrical Engineering Theses - Archive

This thesis presents the design of a new CMOS Voltage Controlled Oscillator and a frequency divider, both of which form important blocks in the design of a PLL synthesizer. These components are important because they operate at the highest frequencies within the PLL and also consume most of the power as compared to the other components. Both these circuits have been an active topic of research in recent years especially with the scaling of technology bringing hopes of complete system-on-chip (SOC) integration at RF frequencies. The circuits in this thesis are designed for 5 GHz applications, mainly for the IEEE …


Design And Development Of Embedded Dsp Controllers For Power Electronic Applications, Raman Nair Harish Gopala Pillai May 2006

Design And Development Of Embedded Dsp Controllers For Power Electronic Applications, Raman Nair Harish Gopala Pillai

Electrical Engineering Theses - Archive

Power applications like motor drives, inverters have complex algorithms that can be used to improve their efficiency. More often reduced manufacturing cost takes precedence over better efficiency. DSPs with their high computational power can provide reduced cost and higher efficiency. Though the cost of a standalone DSP chip has reduced, its integration to form a complete embedded product is an area often overlooked. High frequency of operation, reduced package size, and sensitivity to component placement are some of the factors that affect the interface between input/output devices and the DSP. This thesis presents the design and development of an embedded …


Feasibility Study Of Options For Aging Hydro-Power Generation Facility, Sandip R. Sharma Apr 2006

Feasibility Study Of Options For Aging Hydro-Power Generation Facility, Sandip R. Sharma

Electrical Engineering Theses - Archive

Most of the hydro generation facilities are operating under derated capacity due to various factors. The availability of generation facilities is decreasing, the cost for maintenance is going up and plants are crippled with severe faults leading to outages. The feasibility study for aging hydro-power plant is carried out with an objective to find out the best possible alternative both with respect to reliability of operation and benefit to cost ratio. The multi-criterion weighted average condition evaluation of hydro-electric generator is carried out. A Visual Basic and Microsoft Excel based condition evaluation program is implemented for possible condition decision making …


Adaptive Sampling With Mobile Wsn, Koushil Sreenath Dec 2005

Adaptive Sampling With Mobile Wsn, Koushil Sreenath

Electrical Engineering Theses - Archive

The spatiotemporally varying network topology of mobile sensor networks makes it very suitable for applications such as reconstruction of environmental fields through sampling at locations that maximally reduce the largest uncertainty in the field estimate. Mobile sensor networks comprise of multiple heterogeneous resources and a deadlock-free resource scheduling in the presence of shared and routing resources becomes necessary to schedule the most efficient (cost / energy / time) resource for a task. Location information is imperative in sensor networks for most applications for localized sensing where localizing the network adaptively with no additional hardware is important. Adaptive sampling approaches for …


Data-Logging & Supervisory Control In Wireless Sensor Networks, Choudhury Aditya Narayan Das Dec 2005

Data-Logging & Supervisory Control In Wireless Sensor Networks, Choudhury Aditya Narayan Das

Electrical Engineering Theses - Archive

This thesis mainly emphasizes on the inclusion and implementation of the Supervisory control unit in the wireless sensor networks with a brief overlook on the cross-bow sensors and mobile sentry robots. The aim of this research has been to design an application module which would be able to manipulate the data effectively and support the Discrete Event Controller in generating the rule-based tasks by solving major issues like data-logging, alarm and event reporting and security concerns. The PC-based data logging systems provide the most flexibility, customization, and integration to the Wireless Sensor Network research project. This work has been supported …


Efficient Transcoding Of An Mpeg-2 Bit Stream To An H.264 Bit Stream, Rochelle B. Pereira Dec 2005

Efficient Transcoding Of An Mpeg-2 Bit Stream To An H.264 Bit Stream, Rochelle B. Pereira

Electrical Engineering Theses - Archive

Low complexity fast transcoding of an MPEG-2 elementary stream to an H.264 elementary stream. Objective: MPEG-2 has been a widely accepted video coding standard for various applications ranging from DVD to digital TV broadcast. The new H.264 AVC standard has an even broader perspective to support high and low bit rate multimedia applications on existing and future networks. The advantage in terms of better quality at a lower bit rate is why H.264 is fast replacing MPEG-2. However, the user end hardware had previously been adapted for MPEG-2 streams. This gives rise to a need for portability between MPEG-2 and …


Analysis And Characterization Of Thermal Effects In Analog Circuits, Abhijit Avinash Chaugule Dec 2005

Analysis And Characterization Of Thermal Effects In Analog Circuits, Abhijit Avinash Chaugule

Electrical Engineering Theses - Archive

Dielectrically Isolated Bipolar Junction Transistors (DIBJTs) are used in industry for high speed and high power applications. These devices suffer from thermal heating and are subjected to change in their characteristics. This thesis explores the thermal effects involving the self heating and inter-device heating (thermal coupling) at the device as well as at the circuit level. Systematic analysis of individual device heating characteristics in a particular Current feedback operational amplifier (CFOA) design is carried out, using the VBIC (Vertical Bipolar Inter-company) model in the the Cadence SpectreS simulator. A diagnostic and design procedure is established for circuit designers to determine …


Human Performance Multimeter: Investigation Of The Fourth Generation Prototype, Rahul Mulukutla Dec 2005

Human Performance Multimeter: Investigation Of The Fourth Generation Prototype, Rahul Mulukutla

Electrical Engineering Theses - Archive

The focus of this thesis is the development and investigation related to the newest prototype version of the Human Performance MultiMeter (HPMM). Version 4 is a technologically advanced, compact, portable and self-contained unit that is the result of an on-going effort in human performance measurement covering a 25 year history at the Human Performance Institute involving the conception, development, and evaluation of over four hundred different measures. Such measurements are applicable in areas ranging from medical diagnosis and rehabilitation to ergonomics and athletic proficiency. The work included verification of the functionality of a new hardware platform, modification of previously developed …


Wavelet Domain Diversity Method For Transmission Of Images Over Wireless Sytems Using Hybrid (Ofdm-Cdma-Sfh) Concept And Its Real Time Implementation In Tms320c6713 Dsp Development Board, Madhu Rangappagowda Dec 2005

Wavelet Domain Diversity Method For Transmission Of Images Over Wireless Sytems Using Hybrid (Ofdm-Cdma-Sfh) Concept And Its Real Time Implementation In Tms320c6713 Dsp Development Board, Madhu Rangappagowda

Electrical Engineering Theses - Archive

In this thesis a new OFDM based wavelet domain diversity combining method is proposed to combat errors during image transmission on wireless channels. A novel concept of utilizing OFDM sub-carriers to attain diversity is designed and analyzed. For images represented in the wavelet domain, diversity is used to obtain multiple data streams using OFDM symbols corresponding to the transmitted image at the receiver. These individual image data streams are combined to form a composite image with higher perceptual quality. Both uncompressed and compressed images are considered. The SPIHT algorithm is used for image compression. Diversity combining methods for both uncompressed …


Cmos Optical Transimpedance Amplifier Design For Pam Signaling Application, Hemalatha Shanmugasundaram Dec 2005

Cmos Optical Transimpedance Amplifier Design For Pam Signaling Application, Hemalatha Shanmugasundaram

Electrical Engineering Theses - Archive

The advent of Internet telephony and the surge in data communication field necessitate the use of broadband communication systems. The Optical communication systems has been suggested as an attractive solution to cope with the high speed data rate and large throughput bottleneck of the long haul communication systems due to their cheaper deployment cost. In the world of miniaturization, CMOS circuits have been widely used to develop the opto-electronic components. However, the intricacy involved in the design of high speed optical front-end is higher due to the poor noise performance of CMOS circuits compared to their bipolar counter parts. Despite …


A Cmos Ultra-Wideband Differential Low Noise Amplifier, Timothy Bryan Merkin Nov 2005

A Cmos Ultra-Wideband Differential Low Noise Amplifier, Timothy Bryan Merkin

Electrical Engineering Theses - Archive

In this thesis, a CMOS Ultra-wideband (UWB) Low noise Amplifier (LNA) was designed and simulated. In the design, specific architecture decisions were made in consideration of ultimately including this LNA in a system-on-chip implementation of an Ultra-wideband communication system. The basic architecture of the LNA designed herein exhibits a differential amplifier core with active input and output impedance matching, minimizing the number of expensive space consuming passive inductors necessary for passive impedance matching networks. The LNA maintains a gain of 16.4dB with a ±0.25dB ripple over the band of 3.1-6.2GHz. Despite the use of an active input matching stage, the …


Cmos 5th Derivative Gaussian Impulse Generator For Uwb Application, Shin-Chih Chang Nov 2005

Cmos 5th Derivative Gaussian Impulse Generator For Uwb Application, Shin-Chih Chang

Electrical Engineering Theses - Archive

A complete impulse generating system was designed and simulated which generates the fifth order derivative of the Gaussian pulse intended for use in an impulse-type ultra-wideband wireless communication system. By using a continuous-time FIR impulse shaping filter, the system transforms a normal Gaussian pulse signal obtained from an existing CMOS Gaussian pulse generator into its fifth derivative. The transformation filtering was accomplished without lengthening the time duration of the original pulse or causing any noticeable ringing effects. The final output waveform closely resembles the fifth derivative of the Gaussian pulse, and also satisfies the spectral mask emission requirements specified by …


A Simulation Tool Suite For The Modeling And Optimization Of Multiple Quantum Well Structures, Jeffery Wayne Allen Nov 2005

A Simulation Tool Suite For The Modeling And Optimization Of Multiple Quantum Well Structures, Jeffery Wayne Allen

Electrical Engineering Theses - Archive

This thesis aims to develop a suite of computational tools for design, analysis, and simulation of semiconductor multiple quantum well structures with a user-friendly GUI. The research project focuses on the electrical and optical aspects of user defined quantum well structures, and allows the user to vary design parameters to optimize the structure for different device applications and functionality. Specifically the thesis delves into the design and analysis of different quantum well structures as they relate to band gap engineering. Key features of this computational suite include relationship to electrical field, doping profiles and optical transitions. The quantum well structures …


Optimization Of H.264 Baseline Decoder On Arm9tdmi Processor, Sandya B. Sheshadri Nov 2005

Optimization Of H.264 Baseline Decoder On Arm9tdmi Processor, Sandya B. Sheshadri

Electrical Engineering Theses - Archive

With the newly introduced features and advancements to the pre-existing features, the emerging H.264 video coding standard achieves significant improvements in coding performance over all existing standards, in a wide variety of applications. The coding-efficiency advantages of H.264, however, come at the expense of higher computational complexity. H.264 decoders can exhibit more than double the complexity of H.263 decoders. Furthermore, previous studies have shown that fractional-pixel motion-compensation interpolation and the loop filtering consume a significant amount of computational power in emerging H.264 decoders. Since these operations are part of the baseline profile of H.264, there is a need to evaluate …


Optimization Of H.264 High Profile Decoder For Pentium 4 Processor, Tarun Bhatia Nov 2005

Optimization Of H.264 High Profile Decoder For Pentium 4 Processor, Tarun Bhatia

Electrical Engineering Theses - Archive

H.264 is an emerging video coding standard, which aims at compressing high-quality video content at low-bit rates. While the basic idea behind the encoding and decoding process still remains the same as in the previous standards, many new and innovative tools have been added to provide higher compression capabilities with high perceptual quality. These capabilities have also contributed to the increase in complexity of implementation of H.264 significantly compared to the previous generation of video coding standards. In this thesis, the performance analysis of the H.264 decoder for decoding of high profile high definition data is done for the Pentium …


Improving The Quality Of Low Bitrate Lpc Speech Codec Using Gamma-Chirp Filterbank, Amin Khajeh Djahromi Sep 2005

Improving The Quality Of Low Bitrate Lpc Speech Codec Using Gamma-Chirp Filterbank, Amin Khajeh Djahromi

Electrical Engineering Theses - Archive

In this thesis, two methods for getting higher speech quality in low bit-rate LPC coder in comparison with the original LPC coder were presented. In order to improve the quality of the speech, the embedded method which can take the place of the traditional synthesis algorithm in LPC coders and the post-processing method that also can be used as the last stage in the LPC-coder based systems were proposed. In the embedded method, the result of MOS test of the synthesized speech increased by 0.8 and in the post-processing method the result of MOS test of the synthesized speech increased …


Modeling And Characterization Of A Fabry Perot Pressure Sensor, Shruthika Prasanna Aug 2005

Modeling And Characterization Of A Fabry Perot Pressure Sensor, Shruthika Prasanna

Electrical Engineering Theses - Archive

Fabry-Perot interferometers (FPIs) have been used as sensing elements for pressure transducers in many applications. Most of the current FPI pressure sensors measure amplitude changes of the reflected signals from a deformable diaphragm. A new technique to design an FPI pressure sensor has been proposed in this thesis. The proposed methodology aims to maximize the sensitivity by measuring frequency shifts and optimize the dimensions of the sensors for various materials and applications. The sensor diaphragm is built directly on the end surface of an optical fiber with a sacrificial layer introducing the required FPI cavity height. The resulting sensor detects …


Physics Based Time-Frequency Analysis To Reduce Multi-Bounce And Clutter In Radar Imaging, Anilkumar Kollipara Aug 2005

Physics Based Time-Frequency Analysis To Reduce Multi-Bounce And Clutter In Radar Imaging, Anilkumar Kollipara

Electrical Engineering Theses - Archive

The concept of time-frequency analysis of the scattered far field data from multiple targets is presented. The scattered data from the target is collected using a mono-static antenna configuration. The hardware system and the data acquisition system used in the process are discussed in detail. The results obtained using the ISAR imaging algorithm are presented and the effect of different non-point and dispersive scattering phenomena on these images are discussed. A physics based time-frequency analysis using wavelets is done on this scattered data to reduce the inter-target interactions and thereby produce cleaner images of the target under consideration. The results …