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Electrical and Computer Engineering

Brigham Young University

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Full-Text Articles in Engineering

Model-Based Estimation Of Wind Fields Over The Ocean From Wind Scatterometer Measurements. I. Development Of The Wind Field Model, David G. Long, Jerry M. Mendel May 1990

Model-Based Estimation Of Wind Fields Over The Ocean From Wind Scatterometer Measurements. I. Development Of The Wind Field Model, David G. Long, Jerry M. Mendel

Faculty Publications

For pt.II see ibid., vol.28, no.3, p.361-373 (1990). A parametric model for near-surface mesoscale wind fields suitable for use in a model-based approach to estimate the wind field over a large region of the scatterometer measurement swath from measurements of the radar backscatter of the ocean's surface is discussed. The assumptions made in developing the model are described, and the accuracy of the resulting model is evaluated. The model is based only on scatterometer data and is computationally tractable, consisting of a linear equation relating the near-surface wind field to a vector of model parameters which is estimated from the …

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Model-Based Estimation Of Wind Fields Over The Ocean From Wind Scatterometer Measurements. Ii. Model Parameter Estimation, David G. Long, Jerry M. Mendel May 1990

Model-Based Estimation Of Wind Fields Over The Ocean From Wind Scatterometer Measurements. Ii. Model Parameter Estimation, David G. Long, Jerry M. Mendel

Faculty Publications

For pt.I see ibid., vol.28, no.3, p.349-360 (1990). The feasibility of a model-based approach to wind field estimation is discussed. In this approach the parametric model for near-surface mesoscale wind fields developed in pt.I is used. The parameters of the model are estimated from the wind scatterometer measurements; the wind field estimate is then computed from the estimated model parameters. Unlike the traditional pointwise approach, this approach takes advantage of the inherent correlation in the winds at different sample points to estimate the wind field more accurately and resolve directional ambiguity. The accuracies of wind field estimates obtained using the …

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Decision-Directed Multivariate Empirical Bayes Classification With Nonstationary Priors, Wynn C. Stirling, A. Lee Swindlehurst Sep 1987

Decision-Directed Multivariate Empirical Bayes Classification With Nonstationary Priors, Wynn C. Stirling, A. Lee Swindlehurst

Faculty Publications

A decision-directed learning strategy is presented to recursively estimate (i.e., track) the time-varying a priori distribution for a multivariate empirical Bayes adaptive classification rule. The problem is formulated by modeling the prior distribution as a finite-state vector Markov chain and using past decisions to estimate the time evolution of the state of this chain. The solution is obtained by implementing an exact recursive nonlinear estimator for the rate vector of a multivariate discrete-time point process representing the decisions. This estimator obtains the Doob decomposition of the decision process with respect to the a-field generated by all past decisions and corresponds …

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Simultaneous System Identification And Decision-Directed Detection And Estimation Of Jump Inputs To Linear Systems, Wynn C. Stirling Jan 1987

Simultaneous System Identification And Decision-Directed Detection And Estimation Of Jump Inputs To Linear Systems, Wynn C. Stirling

Faculty Publications

A decision-directed approach is presented for analyzing linear systems with unknown jump inputs. The system model parameters are estimated using a Kalman filter, and an empirical Bayes detection procedure is introduced to set the detector parameters, resulting in a decision-directed generalized likelihood ratio test coupled with recursive system parameter estimation. Monte Carlo results are presented to validate the performance of the algorithm.

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Editing Templates: A User Interface Generation Tool, Dan R. Olsen Jr. Nov 1986

Editing Templates: A User Interface Generation Tool, Dan R. Olsen Jr.

Faculty Publications

This article discusses a basic architecture for a user interface management system and the problem of updating a display in response to interactive commands. The basic architecture is then extended to include basic editing and browsing processes on arbitrary data structures. Editing templates are presented as a technique embodying the entire manipulation process for a particular data structure/data display combination. In conjuction with the user interface management system, Such templates are able to automatically provide a majority of the code required in an interactive applicaton.

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A Theoretical Basis For Practical Amplifier Design Using Cascaded Operational Amplifiers, David J. Comer Aug 1985

A Theoretical Basis For Practical Amplifier Design Using Cascaded Operational Amplifiers, David J. Comer

Faculty Publications

A procedure is developed for the design of amplifiers to meet specified gain and bandwidth figures. The number of required operational amplifier stages is minimised. A figure of merit is introduced to determine if a particular operational amplifier can be used to satisfy a given set of specifications.

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A Unique Microprocessor Instruction Set, D. A. Fairclough May 1982

A Unique Microprocessor Instruction Set, D. A. Fairclough

Faculty Publications

New instruction sets have been based on traditather than on the application of scientific method. Here, the latter has yielded a simple, optimal, en-member instruction set.

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Proton Induced X-Ray Emission Analysis - A Complement To Analytical Methods Used In Environmental Studies, N. F. Mangelson, D. J. Eatough, N. L. Eatough, L. D. Hansen, M. W. Hill, M. L. Lee, L. R. Phillips, M. E. Post, B. E. Richter, J. F. Ryder Apr 1981

Proton Induced X-Ray Emission Analysis - A Complement To Analytical Methods Used In Environmental Studies, N. F. Mangelson, D. J. Eatough, N. L. Eatough, L. D. Hansen, M. W. Hill, M. L. Lee, L. R. Phillips, M. E. Post, B. E. Richter, J. F. Ryder

Faculty Publications

Particle induced X-ray emission (PIXE) analysis is a highly versatile method of element analysis. Thus it is well suited for use as a complement to other methods of analysis in experimental programs requiring both chemical and elemental analyses. This paper reports some results of two projects where PIXE was used in conjunction with titration calorimetry, ion chromatography, atomic absorption spectroscopy, gas chromatography/mass spectrometry, X-ray fluorescence spectroscopy and some other methods. The first is a study of sulfur chemistry in a copper smelter plume. Arsenic was found to be a conservative tracer of the plume and was used for calculation of …

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Multiple Scattering Of Protons And Deuterons By Thick Foils, D. R. Dixon, G. L. Jensen, S. M. Morrill, C. J. Connors, R. L. Walter, C. R. Gould, P. M. Thambiduria Apr 1981

Multiple Scattering Of Protons And Deuterons By Thick Foils, D. R. Dixon, G. L. Jensen, S. M. Morrill, C. J. Connors, R. L. Walter, C. R. Gould, P. M. Thambiduria

Faculty Publications

Protons and deuterons from the Triangle Universities Nuclear Laboratory (TUNL) tandem Van de Graaff of energies 3.0, 4.0, and 5.0 MeV were scattered from foils of Al, Ni, Mo, and Ta having thicknesses of 6.14 to 47 mg/cm2. Multiple scattering angular distributions were measured using a position-sensitive detector to collect data at nine different angles simultaneously. Gaussian curves were fitted to the central points of the distributions and the Θ1/e angles thus derived are presented graphically. The data points are compared with calculations using a common method of determining multiple scattering angles. An empirical correction for extending this method into …

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Two Preliminary Studies Of The Intelligibility Of Predictor-Coefficient And Formant-Coded Speech, L. Keeler, G. Clement, W. Strong, E. Palmer Oct 1976

Two Preliminary Studies Of The Intelligibility Of Predictor-Coefficient And Formant-Coded Speech, L. Keeler, G. Clement, W. Strong, E. Palmer

Faculty Publications

Two preliminary studies comparing the intelligibilities of predictor-coefficient versus formant-frequency-coded speech and the intelligibilities of predictor-coefficient-coded speech using different numbers of coefficients are reported.

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The Topolotron: A High Beta Device With Topological Stability, Keith H. Brown, H. R. P. Ferguson, J. H. Gardner, Larry V. Knight, H. Mark Nelson Sep 1976

The Topolotron: A High Beta Device With Topological Stability, Keith H. Brown, H. R. P. Ferguson, J. H. Gardner, Larry V. Knight, H. Mark Nelson

Faculty Publications

The concept of topological or structural stability is introduced and its importance in the magnetic confinement of plasmas is discussed. Topological stability requires the presence of a pair of limit cycles in the magnetic field configuration. This paper deals with the design of an experimental device possessing limit cycles. The design includes a high beta (b=1), high density (10^16), hot (100 eV) hydrogen plasma which is to be compressed by a factor of about 5 in a torodial device of 25 cm average major radius with a capacitor bank rise time of less than 2 µsec. Two shaped toroidal coils …

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A Circular Active Reflector Atenna (Cara), Energy Distribution Calculations, And An Experimental Test, Larry V. Knight, George H. Barry Mar 1975

A Circular Active Reflector Atenna (Cara), Energy Distribution Calculations, And An Experimental Test, Larry V. Knight, George H. Barry

Faculty Publications

Conventional high-frequency (HF) circular phased arrays, such as the Wullenweber circular array, have a cost factor that increases at a greater-than-square law rate as its radius is increased to produce larger apertures. A new method of forming simultaneous beams in an HF circular array has been proposed in which beams are formed in the space within the array from pickup element energy that has been amplified and reradiated. Such a device is called a circular active reflector antenna (CARA), and its cost increases at a substantially linear rate as its radius is increased to form larger apertures. This paper describes …

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An Intensity-Dependent Filter, James M. Thorne, Thomas R. Loree, George Mccall Jun 1973

An Intensity-Dependent Filter, James M. Thorne, Thomas R. Loree, George Mccall

Faculty Publications

It is useful in optically driven Kerr-cell shutters and other laser applications to have intense pulses with extremely low light levels between pulses. We describe here a device that accomplishes this objective external to the laser cavity.

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Electron Cyclotron Radiation Measurements To Determine Relative Electron Temperatures In A Low-Density Magnetic-Mirror Plasma System, Andrew L. Gardner Feb 1972

Electron Cyclotron Radiation Measurements To Determine Relative Electron Temperatures In A Low-Density Magnetic-Mirror Plasma System, Andrew L. Gardner

Faculty Publications

Measurements of the electron cyclotron radiation emitted from the plasma of the Alice system were made using a synchronous detection microwave radiometer in the range of 10.2 - 11.6 GHz. Both sidebands were used to sample radiation from two nested closed shells within the plasma. For a tenuous plasma this radiation is proportional to the product of the electron density and the electron temperature. Since measurements of the plasma density were available from other detectors, relative values of the electron temperature were obtained using the measured radiation intensity.

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Ehv Ac Parallel Transmission Line Calculations With Application To The Near Resonance Problem, A. Norton Chaston May 1969

Ehv Ac Parallel Transmission Line Calculations With Application To The Near Resonance Problem, A. Norton Chaston

Faculty Publications

The use of shunt reactors with EHV transmission lines has introduced new problems, one of which is induction of high voltages on a de-energized circuit of two parallel lines. This paper presents the matrix equations used in developing a digital computer program which takes into account the effects of electromagnetic induction, electrostatic coupling, distributed lines, and transposition. The computer program may also be used to calculate the effects of shunt reactors, series capacitors, and loads. The equations can be adapted to a wide range of applications, although the examples for this paper have been limited to the near resonance problem …

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An Analysis And Comparison Of Linear Phase Bandpass Filters, Darrell L. Ash Aug 1968

An Analysis And Comparison Of Linear Phase Bandpass Filters, Darrell L. Ash

Theses and Dissertations

The ideal bandpass filter is defined as one which uniformly attenuates and delays all frequency components within the passband and effects zero transmission of all components outside the passband. For reasons which will be subsequently discussed, it is impossible to realize a stable lumped-element filter having this ideal characteristic. This has made it necessary to find ways to physically approximate such a characteristic. Some of the more widely used methods will be compared and analyzed in this paper.

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Control System Digital Computer Transfer Function Simulation, Jens J. Jonson Mar 1962

Control System Digital Computer Transfer Function Simulation, Jens J. Jonson

Faculty Publications

The z transform of simple delay, integrator, leadlag, and differentiator networks are suggested as the basic building blocks for simulating complex control systems on a digital computer. The system parameters retain their explicit identity, thus facilitating analysis and design of the system as a function of specific parameter changes.

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