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Theses/Dissertations

Electronic Theses and Dissertations

2003

Electronics and Electrical.

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A 2-Digit Multidimensional Logarithmic Number System Filterbank Processor For A Digital Hearing Aid., Hongbo (Jennifer). Li Jan 2003

A 2-Digit Multidimensional Logarithmic Number System Filterbank Processor For A Digital Hearing Aid., Hongbo (Jennifer). Li

Electronic Theses and Dissertations

This thesis addresses the design, implementation, and evaluation of a filterbank for digital hearing aids using a Multidimensional Logarithmic Number System (MDLNS). Hearing loss is a function of both frequency and input level. In a typical digital hearing instrument, the hearing loss compensation is performed by separating the incoming sound into several frequency bands which are then compressed to allow the amplification of low level signals while maintaining the amplitude of high level signals. The demands of low power consumption and small size have led to a number of advances in algorithms, semiconductor technologies and system architectures for completely-in-canal (CIC ...


Phoneme-Based Speech Recognition Using Self-Organizing Map., Xiaofeng. Dong Jan 2003

Phoneme-Based Speech Recognition Using Self-Organizing Map., Xiaofeng. Dong

Electronic Theses and Dissertations

Automatic speech recognition by machine is a challenging task for man-machine communications. Because speech waveform is nonlinear and variant, a speech recognition algorithm requires much intelligence and an ability to accommodate variations. In this thesis, a hybrid speech recognizer based on self-organizing map (SOM) and fuzzy neural network (FNN) is proposed. The SOM is used to obtain the optimal phoneme response patterns of speech signal by Viterbi search algorithm and the FNN is applied for the recognition matching of these 2D speech response patterns on the SOM to fulfill the speech recognition tasks. Experiment results show that this hybrid speech ...


A Reconfigurable Digital Multiplier Architecture., Pedram. Mokrian Jan 2003

A Reconfigurable Digital Multiplier Architecture., Pedram. Mokrian

Electronic Theses and Dissertations

The recent growth in microprocessor performance has been a direct result of designers exploiting decreasing device feature sizes, while at the same time deepening the depth of pipelines. As transistor sizes continue to shrink, the traditional gains associated with smaller feature sizes will be degraded due to the adverse effects of wire scaling. The consequences of technology scaling on circuit performance have recently become a topic of significant importance, especially in arithmetic circuitry such as digital multipliers, which exhibit highly irregular interconnections. A digital multiplier architecture will be introduced that alleviates some of the problems associated with interconnect scaling, in ...


Algorithms For Motion Estimation., Songtao. Huang Jan 2003

Algorithms For Motion Estimation., Songtao. Huang

Electronic Theses and Dissertations

This thesis presents several block matching techniques which are utilized for motion estimation in video coding. Among these algorithms the full search algorithm is known for its superiority in the performance over the other matching techniques; this method however requires an enormous computation costs. There are reported techniques in the literature which yield sub-optimal solutions. These are discussed in this thesis while another three efficient motion estimation algorithms for different applications are developed and presented in this thesis. The main objective of these proposed algorithms is to reduce the computation cost while maintaining the performance. Experimental results with a large ...


Automatic Localization Of Craniofacial Landmarks Of Cephalograms Using Artificial Neural Networks., Idris S. El-Feghi Jan 2003

Automatic Localization Of Craniofacial Landmarks Of Cephalograms Using Artificial Neural Networks., Idris S. El-Feghi

Electronic Theses and Dissertations

In modern orthodontic practice, a great reliance is placed on objective and systematic methods of characterizing craniofacial forms, using measurements based on a set of agreed upon points known as craniofacial landmarks. Lateral skull x-ray images are usually used in cephalometric analysis to provide quantitative measurements of the head. Accurate location of those landmarks forms the basis for what is known as cephalometric evaluation. Distance and angles among these landmarks are compared with normative values to diagnose a patient's deviations from ideal form, evaluate the craniofacial growth and measure the effect of the treatment. Because of the large variability ...


Design Of Iir Filters With Canonical Signed-Digit (Csd) Coefficients Using Genetic Algorithms., Li. Liang Jan 2003

Design Of Iir Filters With Canonical Signed-Digit (Csd) Coefficients Using Genetic Algorithms., Li. Liang

Electronic Theses and Dissertations

In this thesis, an optimization method is used in the design of 1-D IIR digital filters, doubly complementary filter pairs and 2-D IIR digital filters. This method uses genetic algorithm (GA) to minimize the mean square error between the desired and the designed filter responses in order to calculate the coefficients of the filter's transfer function. The 1-D IIR filters are designed using cascade structure, and constraints are imposed on the coefficients of the denominator polynomials to ensure stability. In the one-dimensional case, the method is also used to design doubly complementary filter pairs, in which case two filters ...


0.18 Micron Cmos Ip Core Design And Methodology., Joseph Steven. Schrey Jan 2003

0.18 Micron Cmos Ip Core Design And Methodology., Joseph Steven. Schrey

Electronic Theses and Dissertations

When working with 0.18mum or smaller CMOS technologies, current larger technology architectures are not easily scaled and subject to short channel effects. As a result, changes in architecture and/or unconventional transistor sizing must be done. The voltage comparator that has been designed consists of (13) transistors to form the following architectures; a differential input pair, a current mirror and a rail-pulling output stage. Special transistor sizing has been used in the current mirror biasing stage to produce a constant current source for biasing of the input transistors, overcoming the problems of non-constant current and non-constant transconductance due to ...


A Class Of Linear Phase Iir Digital Filters Design., Tao. Dai Jan 2003

A Class Of Linear Phase Iir Digital Filters Design., Tao. Dai

Electronic Theses and Dissertations

Digital IIR filters find wide applications in fields such as speech processing, image processing and noise/echo cancellation. In recent years, the design of linear phase IIR filter becomes a very hot issue of research interest. As we know, FIR filters designed to approximate a magnitude response that has a narrow transition band between the passband and the stopband usually require a large number of multipliers and they have a large delay also. Hence we prefer to IIR digital filters that have less number of multipliers than their corresponding FIR counterparts but one of disadvantages is that an IIR filter ...


Vision-Guided Multiple Planar Object Recognition And Tracking., Shahed. Shahir Jan 2003

Vision-Guided Multiple Planar Object Recognition And Tracking., Shahed. Shahir

Electronic Theses and Dissertations

In order to minimize the cost for any improvement or changes in manufacturing products, a flexible manufacturing system is necessary. To do so, robots should be empowered with equipment like vision sensors, which can work as human eyes for robots. A tracking vision sensor consists of a CCD camera, data acquisition, preprocessing, recognition and tracking modules. In this thesis, a design methodology for invariant recognition-based object tracking is proposed, which can potentially be used for implementation of either vision sensors or tracking vision sensors. The performance of Invariant Recognition-based object tracking to a large extent depends on the object recognition ...


Speech Analysis And Synthesis Based On Arma Lattice Model., Min. Wang Jan 2003

Speech Analysis And Synthesis Based On Arma Lattice Model., Min. Wang

Electronic Theses and Dissertations

The research documented in this thesis presents a pitch synchronous speech analysis and synthesis system using an ARMA (auto regressive moving average) lattice filter. The LP (linear predictive) model is, by far, the most widely used speech production model in speech processing. A well-known drawback with the LP model is that it ignores the effect of the nasal cavity. The mismatch between the model and the vocal tract becomes severe for nasal sound production and leads to poor synthesized speech. The nasal tract effect can be included in the speech production model by representing the vocal tract with an ARMA ...


Simulating The Plenoptic Camera., Arash. Razavi Jan 2003

Simulating The Plenoptic Camera., Arash. Razavi

Electronic Theses and Dissertations

This thesis presents the simulation of a CCD based camera called the Plenoptic Camera. Plenoptic Camera is a novel single lens camera capable of capturing 3D information of the scene and is used to find the depth of the objects. The main concept behind the design of this camera lies in the fact that light which passes through the lens of a camera is quite rich in information which regular cameras are not designed to take advantage of. The plenoptic camera keeps track of the 3D information of the light rays by distributing these rays over a two dimensional array ...


A Digital Tester Architecture For A System-On-Chip Implementation., Rashid. Rashidzadeh Jan 2003

A Digital Tester Architecture For A System-On-Chip Implementation., Rashid. Rashidzadeh

Electronic Theses and Dissertations

This thesis presents the development of an Intellectual Property (IP) core for a System-on-Chip (SoC) implementation of an integrated circuit tester. The resulting realization is called a Tester-on Chip (ToC). The ToC IP core is used in conjunction with a microelectromechanical (MEMS) interface that provides the necessary connectivity between the tester circuitry and the Device Under Test (DUT). Instead of using traditional Automatic Test Equipment (ATE) that includes a complex external test head, the DUT is placed in a MEMS fixture or socket and spring loaded MEMS contacts are used to probe the DUT as required. The ToC implementation can ...


A Mems Acoustical Sensor Array And Associated Micropackage., Sazzadur Chowdhury Jan 2003

A Mems Acoustical Sensor Array And Associated Micropackage., Sazzadur Chowdhury

Electronic Theses and Dissertations

This thesis develops the design methodology and fabrication procedures for a MEMS-based square planar acoustical sensor microarray for use in a hearing instrument to improve speech intelligibility in noisy and reverberant environments. The proposed microarray offers the potential of controlled directional sensitivity with a reasonably constant beamwidth over the audio frequency range when used in conjunction with an appropriate digital signal processor. The microarray consists of nine identical square-shaped capacitive-type acoustical sensors in a 3 x 3 planar layout and has a footprint area of 4.6 x 4.6 mm2 . Each sensor has a sensitivity of 10.3 mV ...


A Mixed-Signal Feed-Forward Neural Network Architecture With On-Chip Learning In Cmos 0.18 Microns., Mitra. Mirhassani Jan 2003

A Mixed-Signal Feed-Forward Neural Network Architecture With On-Chip Learning In Cmos 0.18 Microns., Mitra. Mirhassani

Electronic Theses and Dissertations

One of the main characteristics of the neural networks is their high number of interconnections between the neurons through synaptic multipliers. Interconnections occupy large area and increase the circuit complexity which limits the size of the fully parallel network. To implement large size networks, time-multiplexing should be used. Two new mixed-signal time-multiplexed architectures are proposed for on-chip mixed-signal neural networks. MRIII is used for training the network which is more robust to mixed-signal designs. The problem of node addressing and routing is solved by performing the operations in current mode. The architectures are simple and compact and learning is performed ...


Document Analysis Using Image Processing Techniques., Yi. Lin Jan 2003

Document Analysis Using Image Processing Techniques., Yi. Lin

Electronic Theses and Dissertations

Image thresholding and page segmentation are necessary components of any image understanding and recognition system. In order for an OCR to function properly, texts in a document image has to be isolated and then fed to the OCR for recognition. This requires development of a robust and accurate page segmentation technique. In any page segmentation technique, a preprocessing step in terms of image restoration and thresholding is needed. This thesis therefore concentrates on the development of efficient and robust image thresholding and page segmentation algorithms. In this thesis, three efficient contrast enhancement techniques are proposed that in conjunction with the ...