Signal Processing Commons^™

Adaptive And Fixed Wavelet Features For Narrowband Signal Classification, Anthony J. Pohl

Theses and Dissertations

The application of the multiresolution analysis developed by Mallat to signal classification by Pati and Krishnaprasad and Szu, et al, is further explored in this thesis. Several different wavelet based feature extraction and classification systems are developed and implemented. Methods which rely on the traditional dyadic wavelet decomposition and on the adaptive wavelet representation are presented. Each of the classification systems is implemented for a labeled data set of narrowband signals. Finally, classification results on the full data set and on low frequency Fourier coefficients are provided as baseline comparisons for our work.

The Role Of Frame Selection And Bispectrum Phase Reconstruction For Speckle Imaging Through Atmospheric Turbulence, Elizabeth A. Harpold

Theses and Dissertations

Frame selection using quality sharpness metrics have been shown in previous AFIT theses, to be effective in improving the final product of images obtained using adaptive optics. This thesis extends this idea to noncompensated speckle image data. Speckle image reconstruction is simulated with and without frame selection. Speckle images require the processing of hundreds of data frames. Frame selection is a method of reducing the amount of data required to reconstruct the image. A collection of short exposure image data frames of a single object are sorted based on sharpness metrics. Only the highest quality frames are retained and processed …

Effects Of Jamming And Excision Filtering Upon Error Rates And Detectability Of A Spread Spectrum Communication System, Christopher B. Madden

Theses and Dissertations

This thesis examines the effects of a digital excision filter (DEF) upon the error rates and detectability of a Direct Sequence Binary Phase Shift Keyed communication signal in the presence of both continuous wave (CW) and pulsed jammers. Simulations were performed using the Comdisco Signal Processing Worksystem. Detector models used were the wideband radiometer and two forms of the chip-rate detector. Twelve jamming scenarios were used to test the performance of the DEF in the presence of the CW and pulsed jammers. In addition, the effects of the CW jammer frequency, the pulsed jammer duty cycle, and the pulsed jammer …

Three Dimensional Inverse Synthetic Aperture Radar Imaging, Jack D. Pullis

Theses and Dissertations

This research investigates the generation, display, and interpretation of three-dimensional (3-D) Synthetic Aperture Radar images. Three-dimensional assumes that the data collected consists of one temporal dimension and two orthogonal angular dimensions. From this data, a three dimensional reflectivity map, or 3-D image, of a target can be constructed. This thesis effort develops and applies a three-dimensional imaging algorithm on actual radar data measured on a one-third scale model of a C-29 aircraft. Two-dimensional slices of the three-dimensional image as well as three-dimensional isosurfaces are compared to the physical properties of the target. The results demonstrate the ability to produce three-dimensional …

Computer Aided Detection Of Microcalcifications Utilizing Texture Analysis, Ronald C. Dauk

Theses and Dissertations

A comparative study of texture measures for the classification of breast tissue is presented. The texture features investigated include Angular Second Moments, Power Spectrum Analysis and a novel feature, Laws Energy Ratios. The texture study was accomplished as part of the development of a Model Based Vision (MBV) system for the automatic detection of microcalcifications. An overview of the Microcalcification Detection System is presented, which applies image differencing techniques, feature selection methods, and neural networks for locating microcalcification clusters in mammograms. The Power Spectrum Analysis feature set had the best overall performance with an 83% Probability of Detection and an …

Space Object Identification Using Spatio-Temporal Pattern Recognition, Gary W. Brandstrom

Theses and Dissertations

This thesis is part of a research effort to automate the task of characterizing space objects or satellites based on a sequence of images. The goal is to detect space object anomalies. Two algorithms are considered - the feature space trajectory neural network (FST NN) and hidden Markov model (HMM) classifier. The FST NN was first presented by Leonard Neiberg and David P. Casasent in 1994 as a target identification tool. Kenneth H. Fielding and Dennis W. Ruck recently applied the hidden Markov model classifier to a 3D moving light display identification problem and a target recognition problem, using time …

Three Dimensional Localization Of Lesions From Digitized Mammograms, Amy L. Magnus

Theses and Dissertations

This thesis describes new algorithms to localize regions-of-interests (ROIs) three dimensionally from a pair of digitized mammograms. This work is intended to add a layer of sophistication to computer aided diagnosis by putting to use the fixed and measurable parameters of mammographic imaging. The fixed parameters are the source to film orientation and the podium-image distance. Measurable parameters are the rotation angle of the x-ray tube from the horizontal and the compression depth (the distance from compression paddle to contact podium distance) at the time of imaging. As an additional benefit, three dimensional localization algorithms alleviate the confusion radiologists may …

Narrowband Interference Suppression In Spread Spectrum Communication Systems, James A. Lascody

Theses and Dissertations

Of significant interest to the United States military is the ability of an enemy to deny or disrupt the operation of the Global Positioning System. To combat this threat the GPS JPO initiated the Tactical GPS AntiJam Technology project, which yielded a prototype Digital Excision Filter (DEF) to remove narrowband jammers. This research describes the work performed to get the DEF hardware operational and extends the previous research performed in this area. Comdisco's Signal Processing Worksystem was used to examine the effect of the DEF on the probability of bit error. This research uses peak to average correlation value, probability …

Image Restoration Of Dispersion-Degraded Images From A Liquid-Crystal Beam Steerer, Ronald J. Broessel, Vince Dominic, Russell C. Hardie

Electrical and Computer Engineering Faculty Publications

Liquid-crystal arrays represents one of the first practical technologies capable of steering light by electronic control only. We use such a device to steer the field of view of a broadband imaging sensor. Unfortunately, dispersion degrades the image quality by smearing out details in the image and by introducing multiple diffraction orders (echoes) at the detector plane. We present a method to compensate for these unwanted effects and thus restore the broadband images obtained with the beam steerer. We use the beam-propagation method to find the wavelength-dependent impulse response, from which we determine the appropriate Wiener filter. When training data …

Non-Imaging Infrared Spectral Target Detection, Matthew R. Whiteley

Theses and Dissertations

Automatic detection of time-critical mobile targets using spectral-only infrared radiance data is explored. A quantification of the probability of detection, false alarm rate, and total error rate associated with this detection process is provided. A set of classification features is developed for the spectral data, and these features are utilized in a Bayesian classifier singly and in combination to provide target detection. The results of this processing are presented and sensitivity of the class separability to target set, target configuration, diurnal variations, mean contrast, and ambient temperature estimation errors is explored. This work introduces the concept of atmospheric normalization of …

Linda Jacobson Interview Virtual Reality Evangelist, Loretta L. Lange

SWITCH

In the interview with Linda Jacobson, a Virtual Reality (VR) artist, Jacobson discusses the current and future state of VR technology’s role in the politics of the body, social identity, self, gender, class, and race. This article discusses the fact that barriers to access exist for a more diverse set of artists across race, class, and gender to engage with VR technology and the need to evolve the development platform, so artists can implement their ideas in a low-cost way. The author discusses Jaron Lanier’s ideas about using VR to explore other identities based on a theatrical model where the …

Bandwidth And Additive Bandwidth Of Graphs, Maria Kujawski

Honors Capstone Projects and Theses

No abstract provided.

Three-Dimensional Location Estimation Of Trajectories Of Point Targets Using A Projection-Based Transformation Method, Jae-Ho Choi, Sarah A. Rajala

Sarah A. Rajala

A new computational approach for determining the parameters that characterize the locations of trajectories of point targets in a 3-D space is described. The targets of concern are dim, unresolved point targets moving along straight paths across the same field of view. Since the target's signal-to-noise ratio is low and the spatial extent of the target is less than a pixel, one must rely on integration over a target track that spans many image frames. The proposed method estimates these parameters by transforming the entire set of time-sequential images of a constant field of view into the projection space by …

Optimal Sequence Estimation For Convolutionally Coded Signals With Binary Digital Modulation In Isi Channels, Fuqin Xiong

Electrical and Computer Engineering Faculty Publications

Decoding convolutional codes with binary digital modulation in intersymbol interference (ISI) channels is studied. The receiver structure is a whitened matched filter (WMF) whose transfer function is determined by the ISI channel. Decoding of the output sequence can be performed in two steps or one step. The two-step decoding first decodes the ISI corrupted coded sequence back to the ISI free coded sequence which is then decoded back to the uncoded message sequence. For one-step decoding, the entire encoder-channel-receiver system is modeled as a new encoder with combined memory length of the memory lengths of the original …

Enhanced 911 Service In A Private Branch Exchange Using Uswest Ps/Ali Service

ACUTA: Other Publications

In This Issue

Author

Introduction

EP11 Operation Overview

US West Communications E911 Private Switch/Automatic Location

Identification Feature

Implementation of E911 with PS/ALI At Colorado State University

Overview

Planning ALI Database Input

SL- 100 PBX Database and Trunking

Pre-Testing

Other Issues and Difficulties

Cost

Conclusion

Addendum A

Addendum B

Campus Telecommunications Systems: Managing Change, Association Of College And University Telecommunications Administrators

ACUTA: Other Publications

The purpose of this book is to provide a broadbased understanding of the rapidly changing environment of campus telecommunications. The anticipated audience for this material is the non-technical university administrator who may not have direct responsibility for telecommunications, but has a need to understand the general environment in which his telecommunications manager functions and the basic concepts of the technology. Five topic areas were selected that best cover the preponderance of issues. No attempt has been made to associate or closely coordinate materials from one chapter's subject to that of any other. Each chapter generally stands alone. In total, however, …

A General Approach To Boolean Function Decomposition And Its Application In Fpgabased Synthesis, Tadeusz Luba, Henry Selvaraj

Electrical & Computer Engineering Faculty Research

An effective logic synthesis procedure based on parallel and serial decomposition of a Boolean function is presented in this paper. The decomposition, carried out as the very first step of the .synthesis process, is based on an original representation of the function by a set of r-partitions over the set of minterms. Two different decomposition strategies, namely serial and parallel, are exploited by striking a balance between the two ideas. The presented procedure can be applied to completely or incompletely specified, single- or multiple-output functions and is suitable for different types of FPGAs including XILINX, ACTEL and ALGOTRONIX devices. The …

Video Coding For Bit Rates 64kbps And Below, Geoffrey N. Alagoda

Theses : Honours

With digital motion video for either transmission or storage, there always exists a trade-off between the data transmission rate and the picture quality. The lower the transmission bit-rate is made, the more the quality of the image tends to degrade. With usual transform coding schemes the degradation usually occurs when low bit-rates, that is less than about 64Kbps, are used. The resultant image tends to suffer visually from a ''blocking" effect. This thesis therefore, is based on the development of a different implementation scheme, for motion video compression or encoding, so as to support both low bit-rates, around 64Kbps or …

Cossap Simulation Model Of Ds-Cdma Indoor Microwave Atm Lan, Keng T. Tan

Theses : Honours

This thesis presents an original work in the area of designing and implementing a simulation testbed for modelling a high speed spread spectrum Asynchronous Transfer Mode (ATM) Local Area Network (LAN). The spread spectrum technique used in this LAN model is Direct Sequence Code Division Multiple Access (DS-CDMA). The simulation model includes at least a physical layer of such a LAN, embedded into the COSSAP¹ simulation environment, and has been fully tested. All the newly developed building blocks are comprised of standard blocks from the COSSAP libraries or compatible user-built primitive blocks (only where it is absolutely necessary), and …

Time-Frequency Shift-Tolerance And Counterpropagation Network With Applications To Phoneme Recognition, Li-Minn Ang

Theses : Honours

Human speech signals are inherently multi-component non-stationary signals. Recognition schemes for classification of non-stationary signals generally require some kind of temporal alignment to be performed. Examples of techniques used for temporal alignment include hidden Markov models and dynamic time warping. Attempts to incorporate temporal alignment into artificial neural networks have resulted in the construction of time-delay neural networks. The nonstationary nature of speech requires a signal representation that is dependent on time. Time-frequency signal analysis is an extension of conventional time-domain and frequency-domain analysis methods. Researchers have reported on the effectiveness of time-frequency representations to reveal the time-varying nature of …