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Electrical and Computer Engineering Faculty Research & Creative Works

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Articles 3271 - 3300 of 3518

Full-Text Articles in Engineering

Terrain Classification In Sar Images Using Principal Components Analysis And Neural Networks, Mahmood R. Azimi-Sadjadi, Saleem Ghaloum, R. Zoughi Mar 1993

Terrain Classification In Sar Images Using Principal Components Analysis And Neural Networks, Mahmood R. Azimi-Sadjadi, Saleem Ghaloum, R. Zoughi

Electrical and Computer Engineering Faculty Research & Creative Works

The development of a neural network-based classifier for classifying three distinct scenes (urban, park and water) from several polarized SAR images of San Francisco Bay area is discussed. The principal component (PC) scheme or Karhunen-Loeve (KL) transform is used to extract the salient features of the input data, and to reduce the dimensionality of the feature space prior to the application to the neural networks. Employing PC scheme along with polarized images used in this study, led to substantial improvements in the classification rates when compared with previous studies. When a combined polarization architecture is used the classification rate for …

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Open-Ended Rectangular Waveguide For Nondestructive Thickness Measurement And Variation Detection Of Lossy Dielectric Slabs Backed By A Conducting Plate, Sasan Bakhtiari, Stoyan I. Ganchev, R. Zoughi Feb 1993

Open-Ended Rectangular Waveguide For Nondestructive Thickness Measurement And Variation Detection Of Lossy Dielectric Slabs Backed By A Conducting Plate, Sasan Bakhtiari, Stoyan I. Ganchev, R. Zoughi

Electrical and Computer Engineering Faculty Research & Creative Works

Solutions of fields inside a slab of a generally lossy dielectric medium backed by a conducting plate, placed outside a waveguide-fed rectangular aperture, are evoked in the application to the microwave nondestructive thickness measurement of such dielectric slabs. Upon construction of the waveguide terminating admittance expression from its variational form, an inverse problem is then solved to extract the slab thickness from the conductance and susceptance in a recursive manner. A comparison between the experimental and theoretical results showed that the significance of higher order modes is minimal; hence, the dominant mode assumption is, in general, valid to describe the …

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A Fast Converging, Low Complexity Adaptive Filtering Algorithm, Steven L. Grant Jan 1993

A Fast Converging, Low Complexity Adaptive Filtering Algorithm, Steven L. Grant

Electrical and Computer Engineering Faculty Research & Creative Works

This paper introduces a new adaptive filtering algorithm called fast affine projections (FAP). Its main attributes include RLS (recursive least squares) like convergence and tracking with NLMS (normalized least mean squares) like complexity. This mix of complexity and performance is similar to the recently introduced fast Newton transversal filter (FNTF) algorithm. While FAP shares some similar properties with FNTF it is derived from a different perspective, namely the generalization of the affine projection interpretation of NLMS. FAP relies on a sliding windowed fast RLS (FRLS) algorithm to generate forward and backward prediction vectors and expected prediction error energies. Since sliding …

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A New Technique To Decompose Closely Spaced Interface And Bulk Trap States Using Temperature Dependent Pulse-Width Deep Level Transient Spectroscopy Method: An Application To Pt/Cds Photodetector, C. W. Wang, Cheng-Hsiao Wu, Jack L. Boone Jan 1993

A New Technique To Decompose Closely Spaced Interface And Bulk Trap States Using Temperature Dependent Pulse-Width Deep Level Transient Spectroscopy Method: An Application To Pt/Cds Photodetector, C. W. Wang, Cheng-Hsiao Wu, Jack L. Boone

Electrical and Computer Engineering Faculty Research & Creative Works

A novel method is presented here to experimentally decompose nonexponential capacitive transients into the appropriate components from the closely spaced deep trap states. Using temperature dependent pulse-width deep level transient spectroscopy (TDP-DLTS) technique, we show for the first time that two bulk trap states and one continuously distributed interface states in (Pt/CdS) photodiodes can be successfully separated. The basic principle is to set the applied pulse width to follow an averaged temperature-dependent capture time constant and divide the DLTS spectrum. In the example of Pt/CdS photodiodes, we show that all physical parameters including thermal activation energies, capture cross sections, and …

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Advanced Graphics Zoom In On Operations, Max Darwin Anderson, Hardy J. Pottinger, C. M. Schroeder Jan 1993

Advanced Graphics Zoom In On Operations, Max Darwin Anderson, Hardy J. Pottinger, C. M. Schroeder

Electrical and Computer Engineering Faculty Research & Creative Works

No abstract provided.

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Battery Energy Storage Technologies, Max Darwin Anderson, Dodd S. Carr Jan 1993

Battery Energy Storage Technologies, Max Darwin Anderson, Dodd S. Carr

Electrical and Computer Engineering Faculty Research & Creative Works

Battery energy storage systems, comprising lead-acid batteries, power conversion systems, and control systems, are in commercial operation around the world. They are used by three main groups: power generating utilities; power distributing utilities; and major power consumers (such as electric furnace foundries). The principal advantages of battery energy storage systems to generating utilities include load leveling; frequency control; spinning reserve; modular construction; convenient siting; no emissions; and investment deferral for new generation and transmission equipment. Power distributing utilities and major power consumers can avoid costly demand changes by discharging their batteries at peak periods and then recharging with lower cost …

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Lightning Arrester Failure And Ferroresonance On A Distribution System, L. J. Bohmann, J. Mcdaniel, Eldon Keith Stanek Jan 1993

Lightning Arrester Failure And Ferroresonance On A Distribution System, L. J. Bohmann, J. Mcdaniel, Eldon Keith Stanek

Electrical and Computer Engineering Faculty Research & Creative Works

Since 1987 the Upper Peninsula Power Company (UPPCO) has been experiencing a large number of lightning arrester failures on a portion of their distribution system in southern Marquette County, Michigan. It was in the area of the Navy's Extremely Low Frequency (ELF) antenna where the distribution system had been recently reconfigured so that the transformers were connected line-to-line in order to eliminate interference from the antenna. A study was done which determined that the system was susceptible to ferro resonance during single line faults under lightly loaded conditions and that the overvoltage's experienced could be causing the lightning arrester failures. …

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Robust Control Of Flexible Structures Using Multiple Shape Memory Alloy Actuators, R. Lashlee, R. Butler, Vittal S. Rao, F. Kern Jan 1993

Robust Control Of Flexible Structures Using Multiple Shape Memory Alloy Actuators, R. Lashlee, R. Butler, Vittal S. Rao, F. Kern

Electrical and Computer Engineering Faculty Research & Creative Works

The design and implementation of control strategies for large, flexible smart structures presents challenging problems. To demonstrate the capabilities of shape-memory-alloy actuators, we have designed and fabricated a three-mass test article with multiple shape-memory-alloy (NiTiNOL) actuators. The force and moment actuators were implemented on the structure to examine the effects of control structure interaction and to increase actuation force. These SMA actuators exhibit nonlinear effects due to dead band and saturation. The first step in the modeling process was the experimental determination of the transfer function matrix derived from frequency response data. A minimal state space representation was determined based …

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Emc Applications Of Emap-2: A 3d Finite Element Modeling Code, Todd H. Hubing, M. Ali Jan 1993

Emc Applications Of Emap-2: A 3d Finite Element Modeling Code, Todd H. Hubing, M. Ali

Electrical and Computer Engineering Faculty Research & Creative Works

EMAP-2, a 3-D finite element modeling code that can be used to model simple printed circuit board configurations, is discussed. It is a true full-wave field solver designed to be used for education or research. EMAP-2 is written in the C programming language. The code, its capabilities, and its limitations are described. Two examples illustrate how the code can be applied to problems of particular interest to EMC (electromagnetic compatibility) engineers.

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Efficient Simulation Of Multicarrier Digital Communication Systems In Nonlinear Channel Environments, Kevin W. Schneider, William H. Tranter Jan 1993

Efficient Simulation Of Multicarrier Digital Communication Systems In Nonlinear Channel Environments, Kevin W. Schneider, William H. Tranter

Electrical and Computer Engineering Faculty Research & Creative Works

The effectiveness of computer simulation as a tool for the design and analysis of communication systems is often limited by the long execution times required for many simulations. When simulating multicarrier digital communication systems operating over nonlinear channels, the required high sampling rate contributes significantly to long execution times. A new method that reduces the sampling rate of simulations of such systems is developed. This Partial Sum of Products (ParSOP) method reduces the sampling rate by generating only the intermodulation products that lie in a frequency band of interest. The ParSOP method requires that the bandpass nonlinearity be represented by …

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An Optoelectronic Implementation Of The Adaptive Resonance Neural Network, Donald C. Wunsch, T. P. Caudell, R. J. Marks, R. A. Falk, C. David Capps Jan 1993

An Optoelectronic Implementation Of The Adaptive Resonance Neural Network, Donald C. Wunsch, T. P. Caudell, R. J. Marks, R. A. Falk, C. David Capps

Electrical and Computer Engineering Faculty Research & Creative Works

A solution to the problem of implementation of the adaptive resonance theory (ART) of neural networks that uses an optical correlator which allows the large body of correlator research to be leveraged in the implementation of ART is presented. The implementation takes advantage of the fact that one ART-based architecture, known as ART1, can be broken into several parts, some of which are better to implement in parallel. The control structure of ART, often regarded as its most complex part, is actually not very time consuming and can be done in electronics. The bottom-up and top-down gated pathways, however, are …

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Automatic Color Segmentation Algorithms-With Application To Skin Tumor Feature Identification, Scott E. Umbaugh, Randy Hays Moss, William V. Stoecker, G. A. Hance Jan 1993

Automatic Color Segmentation Algorithms-With Application To Skin Tumor Feature Identification, Scott E. Umbaugh, Randy Hays Moss, William V. Stoecker, G. A. Hance

Electrical and Computer Engineering Faculty Research & Creative Works

Two color-image segmentation methods are described. The first is based on a spherical coordinate transform of original RGB data. The second is based on a mathematically optimal transform, the principal components transform (also known as eigenvector, discrete Karhunen-Loeve, or Hotelling transform). These algorithms are applied to the extraction from skin tumor images of various features such as tumor border, crust, hair scale, shiny areas, and ulcer. The results of this research will be used in the development of a computer vision system that will serve as the visual front-end of a medical expert system to automate visual feature identification for …

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Faulty Behavior Of Storage Elements And Its Effects On Sequential Circuits, Waleed K. Al-Assadi, Y. K. Malaiya, A. P. Jayasumana Jan 1993

Faulty Behavior Of Storage Elements And Its Effects On Sequential Circuits, Waleed K. Al-Assadi, Y. K. Malaiya, A. P. Jayasumana

Electrical and Computer Engineering Faculty Research & Creative Works

It is often assumed that the faults in storage elements (SEs) can be modeled as output/input stuck-at faults of the element. They are implicitly considered equivalent to the stuck-at faults in the combinational logic surrounding the SE cells. Transistor-level faults in common SEs are examined here. A more accurate higher level fault model for elementary SEs that better represents the physical failures is presented. It is shown that a minimal (stuck-at) model may be adequate if only modest fault coverage is desired. The enhanced model includes some common fault behaviors of SEs that are not covered by the minimal fault …

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Modeling Of Intra-Cell Defects In Cmos Sram, Waleed K. Al-Assadi, Y. K. Malaiya, A. P. Jayasumana Jan 1993

Modeling Of Intra-Cell Defects In Cmos Sram, Waleed K. Al-Assadi, Y. K. Malaiya, A. P. Jayasumana

Electrical and Computer Engineering Faculty Research & Creative Works

The effect of defects within a single cell of a static random access memory (SRAM) is examined. All major types of faults, including bridging, transistor stuck-open and stuck-on, are examined. A significant fraction of all faults cause high IDDQ values to be observed. Faults leading to inter-cell coupling are identified.

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Neural Networks In The Former Soviet Union, Donald C. Wunsch Jan 1993

Neural Networks In The Former Soviet Union, Donald C. Wunsch

Electrical and Computer Engineering Faculty Research & Creative Works

No abstract provided.

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Use Of Storage Elements As Primitives For Modeling Faults In Synchronous Sequential Circuits, Waleed K. Al-Assadi, Y. K. Malaiya, A. P. Jayasumana Jan 1993

Use Of Storage Elements As Primitives For Modeling Faults In Synchronous Sequential Circuits, Waleed K. Al-Assadi, Y. K. Malaiya, A. P. Jayasumana

Electrical and Computer Engineering Faculty Research & Creative Works

No abstract provided.

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Photovoltaic-Powered Water Pumping-Design, And Implementation: Case Studies In Wyoming, Badrul H. Chowdhury, S. Ula, K. Stokes Jan 1993

Photovoltaic-Powered Water Pumping-Design, And Implementation: Case Studies In Wyoming, Badrul H. Chowdhury, S. Ula, K. Stokes

Electrical and Computer Engineering Faculty Research & Creative Works

A photovoltaic-powered water pumping project comprising of several rural electric cooperatives and their customers is described in detail. A number of remote water pumping installations in the state of Wyoming, USA, are currently operating as a result of this project. The design, installation and performance monitoring of these systems are discussed. In general, it can be stated that PV-powered water pumping in this state has been a cost-effective alternative to distribution line extension or other conventional means of water pumping. Customer satisfaction, in terms of functional adequacy and low maintenance requirements of these systems, is high. The benefit for the …

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Analog Chips And Intelligent Vehicles, J. G. Harris Jan 1993

Analog Chips And Intelligent Vehicles, J. G. Harris

Electrical and Computer Engineering Faculty Research & Creative Works

Numerous digital-based sensor systems have been demonstrated on intelligent vehicles but only the most rudimentary experiments have been attempted with analog VLSI chips in real-world environments. The most significant factor in the choice between analog and digital approaches to sensory processing in intelligent vehicles will be the cost of mass production. If analog sensors can be designed with enough speed, resolution and accuracy to solve sensory processing tasks, then the low-cost of mass production ensures that analog circuits will be the technology of choice for future generations of smart sensors. Current analog VLSI sensors do not have enough resolution and …

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Artificial Intelligence Applied To Detection Of Melanoma, Arve Kjoelen, Scott E. Umbaugh, William V. Stoecker, Randy Hays Moss Jan 1993

Artificial Intelligence Applied To Detection Of Melanoma, Arve Kjoelen, Scott E. Umbaugh, William V. Stoecker, Randy Hays Moss

Electrical and Computer Engineering Faculty Research & Creative Works

No abstract provided.

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Photoluminescence And Raman Studies Of Cds Films Grown By Metal-Organic Chemical Vapor Deposition On Si{111} Substrates, Alok K. Berry, P. M. Amirtharaj, Jing Tong Du, Jack L. Boone, Don D. Martin Oct 1992

Photoluminescence And Raman Studies Of Cds Films Grown By Metal-Organic Chemical Vapor Deposition On Si{111} Substrates, Alok K. Berry, P. M. Amirtharaj, Jing Tong Du, Jack L. Boone, Don D. Martin

Electrical and Computer Engineering Faculty Research & Creative Works

CdS epitaxial films grown using metal-organic chemical vapor deposition on Si{111} substrates at growth temperatures ranging from 270 to 325 °C have been characterized using photoluminescence and Raman spectroscopy. Out of all the samples the best optical behavior is obtained from that grown at the lowest temperature. Samples grown at the lowest temperature exhibited increased intensity of the bound excitonic peaks and reduced emission at the defect-related luminescence region. The Raman spectra were compatible with the film surface being normal to the c axis, indicating a preferred growth orientation. © 1992.

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Conservative Confidence Intervals Of Importance Sampling Estimates, Kurt Louis Kosbar, T. F. Chang Oct 1992

Conservative Confidence Intervals Of Importance Sampling Estimates, Kurt Louis Kosbar, T. F. Chang

Electrical and Computer Engineering Faculty Research & Creative Works

Confidence intervals (CI) are used to gauge the accuracy of bit error rate (BER) estimates produced by Monte Carlo (MC) simulations. This work attempts to objectively evaluate the performance of Important Sampling (IS) simulations by applying the same statistical analysis tool. While it is not possible to evaluate the minimum size CI for arbitrary IS estimates, it is possible to over-bound the interval using a technique called conservative confidence interval (CCI) estimation. This bounding procedure is applied to a simple IS biasing technique. While the IS estimate may be superior to the MC estimate, the CCI fails to support this …

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Interval Estimation And Monte Carlo Simulation Of Digital Communication Systems, Kurt Louis Kosbar, T. F. Chang Oct 1992

Interval Estimation And Monte Carlo Simulation Of Digital Communication Systems, Kurt Louis Kosbar, T. F. Chang

Electrical and Computer Engineering Faculty Research & Creative Works

This work quantifies the accuracy of bit error rate (BER) estimates produced by Monte Carlo simulations by carefully applying confidence interval estimation techniques. Due to numerical difficulties, some previous work in this area has assumed that the BER statistic possessed a Gaussian distribution. This work demonstrates that in some important regions the estimate is decidedly non-Gaussian, and application of central limit theorem arguments can result in errors in excess of an order of magnitude. This work investigates the accuracy of common approximations and the feasibility of exact calculation of confidence intervals, and presents a novel polynomial class approximation. By combining …

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Object-Oriented Modeling Of Communication Systems, Kurt Louis Kosbar, Kevin W. Schneider Oct 1992

Object-Oriented Modeling Of Communication Systems, Kurt Louis Kosbar, Kevin W. Schneider

Electrical and Computer Engineering Faculty Research & Creative Works

Conventional communication system simulation programs and packages are written using procedural programming languages. Newly developed, object-oriented languages offer the simulation designer significantly different options and structures. By exploiting these new techniques it is possible to significantly increase the flexibility and extensibility of the simulation package. This allows the system analyst to efficiently re-use complex simulation code and quickly and reliably reconfigure the simulation. In addition, a single object-oriented simulation can be used in all stages of the design process, from conceptual design through fabrication and testing. A final benefit of the object-oriented techniques is that the simulation code closely matches …

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A Novel Numerical Technique For Dielectric Measurement Of Generally Lossy Dielectrics, Stoyan I. Ganchev, Sasan Bakhtiari, R. Zoughi Jun 1992

A Novel Numerical Technique For Dielectric Measurement Of Generally Lossy Dielectrics, Stoyan I. Ganchev, Sasan Bakhtiari, R. Zoughi

Electrical and Computer Engineering Faculty Research & Creative Works

A method for determining the dielectric properties of infinite half-space of generally lossy dielectric materials is described. This method utilizes the measurement of the admittance of a rectangular waveguide radiating into such dielectrics. It is shown that the real part of the admittance is relatively insensitive to the variations of the imaginary part of the dielectric constant. Subsequently, a numerical procedure is initiated which provides a simple and fast-converging approach for calculating the dielectric properties. This numerical procedure lends itself to implementation by personal computers--a major advantage over the existing computational schemes. The theoretical formulation for the expression of the …

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The Interaction Of System Structure, Index, And Numerical Stability In Classes Of Differential/Algebraic Systems, Mariesa Crow May 1992

The Interaction Of System Structure, Index, And Numerical Stability In Classes Of Differential/Algebraic Systems, Mariesa Crow

Electrical and Computer Engineering Faculty Research & Creative Works

Systems which are difficult to solve numerically have always been considered to be ill-conditioned and their analysis has been somewhat neglected. Recent advances in DAE theory have established that, although high-index DAE systems pose some interesting challenges, they are not the anathema they were once thought to be. This paper will present several examples of DAE systems which arise in power systems and non-linear circuit analysis and will discuss both the analytical and numerical challenges these systems pose.

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A Lower-Bound For The Error-Variance Of Maximum-Likelihood Delay Estimates Of Discontinuous Pulse Waveforms, Kurt Louis Kosbar, Andreas D. Polydoros Mar 1992

A Lower-Bound For The Error-Variance Of Maximum-Likelihood Delay Estimates Of Discontinuous Pulse Waveforms, Kurt Louis Kosbar, Andreas D. Polydoros

Electrical and Computer Engineering Faculty Research & Creative Works

A new lower bound is developed for the error variance of maximum-likelihood time-delay estimation when the received signal is a square pulse, corrupted by additive white Gaussian noise. The bound is generated by combining concepts previously developed for a special class of stochastic processes, induced by the signal model. For moderate signal to noise ratios, the new bound is significantly tighter than previously known ones.

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Efficient Simulation Of Multi-Carrier Digital Communication Systems In Nonlinear Channel Environments, K. W. Schneider, William H. Tranter Jan 1992

Efficient Simulation Of Multi-Carrier Digital Communication Systems In Nonlinear Channel Environments, K. W. Schneider, William H. Tranter

Electrical and Computer Engineering Faculty Research & Creative Works

For systems that contain both frequency division multiplexing and bandpass nonlinearities, the high sampling rate that is necessary for accurate simulation contributes to the long runtimes. A partial sum of products (ParSOP) method is proposed to reduce the sampling rate of such systems. The ParSOP method allows the simulation sampling frequency to be reduced by only generating those intermodulation products that are centered in the bandwidth of the single observed modulated subcarrier. Simulation results, obtained by using the complex power series nonlinear model on a filtered binary phase shift keying system, showed that a reduction in the simulation runtime by …

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The Error Probability Of Reed-Solomon Coding And Interleaving On A Bursty-Noise Channel, W. J. Ebel, William H. Tranter Jan 1992

The Error Probability Of Reed-Solomon Coding And Interleaving On A Bursty-Noise Channel, W. J. Ebel, William H. Tranter

Electrical and Computer Engineering Faculty Research & Creative Works

A useful bursty-noise channel model is proposed and, using this model, a binary communication system using Reed-Solomon coding and interleaving is analyzed. The model includes both thermal noise, which gives rise to random errors, and burst noise, which gives rise to error bursts. Error probabilities are derived for the uncoded system, and error probability bounds are derived for the coded system. Monte Carlo simulation results agree well with theory.

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New Emc Design Guidelines For Multilayer Printed Wiring Boards, Todd H. Hubing, Thomas Van Doren Jan 1992

New Emc Design Guidelines For Multilayer Printed Wiring Boards, Todd H. Hubing, Thomas Van Doren

Electrical and Computer Engineering Faculty Research & Creative Works

No abstract provided.

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Hybrid Clamping In Ntsc Digital Video Equipment, Norman R. Cox, Douglas William Irwin Jan 1992

Hybrid Clamping In Ntsc Digital Video Equipment, Norman R. Cox, Douglas William Irwin

Electrical and Computer Engineering Faculty Research & Creative Works

Two algorithms that are suitable for deriving the blanking level of a National Television Systems Committee (NTSC) composite video signal are described. One method consists of averaging digitized color-burst samples taken from successive scan lines. A second method involves processing a group of samples taken from a single burst interval. Either algorithm used in a hybrid clamping arrangement results in automatic drift compensation and the ability to tie the back porch or sync tip to a predetermined digital output code. This aids in matching the analog signal to the input of the analog-to-signal (A/D) converter for maximum signal-to-noise ratio (SNR). …

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