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- Department of Electrical and Computer Engineering: Faculty Publications (7)
- Department of Electrical and Computer Engineering: Faculty Publications (to 2015) (2)
- Department of Computer Science and Engineering: Dissertations, Theses, and Student Research (1)
- Department of Industrial and Management Systems Engineering: Faculty Publications (1)
Articles 1 - 11 of 11
Full-Text Articles in Engineering
System And Method For Performing Optical Code Division Multiple Access Communication Using Bpolar Codes, James F. Young, Benhaam Aazhnag, Lim Nguyen
System And Method For Performing Optical Code Division Multiple Access Communication Using Bpolar Codes, James F. Young, Benhaam Aazhnag, Lim Nguyen
Department of Electrical and Computer Engineering: Faculty Publications
An optical encoding and decoding system which performs code-division multiple access (CDMA) communication in the incoherent, or direct detection, optical domain using bipolar +1/-1 codes. The present invention uses code modu lation and detection principles that permit all-optical imple mentation of the bipolar. +1/-1. code and correlation detec tion that have been developed for the radio frequency (RF) systems. This is possible in spite of the non-negative, or unipolar, +1/0, nature of the incoherent optical system that only detects and processes the signal intensity. The unipolar optical system of the present invention is equivalent to the bipolar RF system in …
Implementation Of A Database System With Boolean Algebra Constraints, András Salamon
Implementation Of A Database System With Boolean Algebra Constraints, András Salamon
Department of Computer Science and Engineering: Dissertations, Theses, and Student Research
This thesis describes an implementation of a constraint database system with constraints over a Boolean Algebra of sets. The system allows within the input database as well as the queries equality, subset-equality and monotone inequality constraints between Boolean Algebra terms built up using the operators of union, intersection and complement. Hence the new system extends the earlier DISCO system, which only allowed equality and subset-equality constraints between Boolean algebra variables and constants. The new system allows Datalog with Boolean Algebra constraints as the query lan- guage. The implementation includes an extension of Naive and Semi-Naive evaluation methods for Datalog programs …
Design, Performance, And Applications Of A Coherent Ultra-Wideband Random Noise Radar, Ram M. Narayanan, Yi Xu, Paul D. Hoffmeyer, John O. Curtis
Design, Performance, And Applications Of A Coherent Ultra-Wideband Random Noise Radar, Ram M. Narayanan, Yi Xu, Paul D. Hoffmeyer, John O. Curtis
Department of Electrical and Computer Engineering: Faculty Publications
A novel coherent ultra-wideband radar system operating in the 1- to 2-GHz frequency range has been developed recently at the University of Nebraska. The radar system transmits white Gaussian noise. Detection and localization of buried objects is accomplished by correlating the reflected waveform with a time-delayed replica of the transmitted waveform. Broadband dual-polarized log-periodic antennas are used for transmission and reception. A unique signal-processing scheme is used to inject coherence into the system by frequency translation of the ultrawideband signal by a coherent 160-MHz phase-locked source prior to performing heterodyne correlation. The system coherence allows the extraction of a target’s …
Electromagneticbeamdirecting Means-Sampleanalyss System Stage, And Method Of Use, Daniel W. Thompson, Darin W. Glenn, John A. Woollam
Electromagneticbeamdirecting Means-Sampleanalyss System Stage, And Method Of Use, Daniel W. Thompson, Darin W. Glenn, John A. Woollam
Department of Electrical and Computer Engineering: Faculty Publications
Disclosed is an electromagnetic beam directing means for use with sample analysis systems, such as reflectometers, ellipsometers and polarimeters and the like, use of which facilitates investigation of sample systems which are not mounted to a sample analysis system sample system supporting stage. The present invention eliminates the requirement of extensive sample analysis system component realignment when alternatingly performing analysis of sample systems mounted upon, and mounted other than upon, a sample analysis system sample system supporting stage.
Apparatus And Method For Detection And Concentration Measurement Of Trace Metals Using Laser Induced Breakdown Spectroscopy, Dennis R. Alexander
Apparatus And Method For Detection And Concentration Measurement Of Trace Metals Using Laser Induced Breakdown Spectroscopy, Dennis R. Alexander
Department of Electrical and Computer Engineering: Faculty Publications
A method and apparatus for in situ detection and concentration measurement of trace elements in an analysis Sample is disclosed. The invention uses laser induced breakdown spectroscopy (LIBS) wherein femtosecond pulsed laser energy is employed to produce the plasma. The femtosecond pulsed laser energy is focused on the analysis Sample to produce the plasma and the resulting emission is delivered for spectral analysis. Because the method and apparatus of the present invention allow breakdown of the analysis Sample without propagation of energy to the Sample-air interface, a plasma is produced that consists essentially of Sample materials without being contaminated by …
Infrared Ellpsometer/ Polarmeter System, Method Of Calibration, And Use Thereof, Daniel W. Thompson, Blaine D. Johs
Infrared Ellpsometer/ Polarmeter System, Method Of Calibration, And Use Thereof, Daniel W. Thompson, Blaine D. Johs
Department of Electrical and Computer Engineering: Faculty Publications
A sample system investigation system, such as an ellipsometer or polarimeter system, for use in investigating sample systems with electromagnetic wavelengths in the infrared range, and a calibration method for compensating nonidealities in multi-dimensional system rotated and non-rotated component representing matricies, are disclosed. An essentially achromatic compensator of dual-rhomb construction, which introduces a (3*LAMBDA/4) phase shift, but essentially no deviation in the direction of propagation of a polarized beam of electromagnetic wavelengths caused to pass there through, even when said compensator is caused to continuously rotate, is also disclosed.
A New Radiosonde System For Profiling The Lower Troposphere, Brian R Corner, Robert D. Palmer
A New Radiosonde System For Profiling The Lower Troposphere, Brian R Corner, Robert D. Palmer
Department of Electrical and Computer Engineering: Faculty Publications
A new, inexpensive radiosonde transmitter and receiver system has been developed for measuring wind field inhomogeneities in the planetary boundary layer using multiple simultaneously launched balloons. The radio- sondes use a narrowband-frequency-modulated carrier signal to transmit atmospheric pressure and temperature information to a surface receiver. The pressure and temperature data transmitted by the radiosondes allow their height above the surface to be ascertained. In addition, the radiosondes can be tracked with a photographic camera system to provide the azimuth and elevation angles of the radiosondes during their ascent, so that their three-dimensional horizontal position can be determined. By tracking the …
Electromagnetic Beam Directing Means-Sample Analysis System Stage, And Method Of Use, Daniel W. Thomspon, Darin W. Glenn, John A. Woollam
Electromagnetic Beam Directing Means-Sample Analysis System Stage, And Method Of Use, Daniel W. Thomspon, Darin W. Glenn, John A. Woollam
Department of Electrical and Computer Engineering: Faculty Publications
Disclosed is an electromagnetic beam directing means for use with sample analysis systems, such as relfectometers, ellipsometers and polarimeters and the like, use of which facilitates investigation of sample systems which are not mounted to a sample analysis system sample system supporting stage. The present invention eliminates the requirement os extensice sample analysis system component realignment when alternatingly performing analysis of sample systems mounted upon, and mounted other than upon, a sample analysis system sample system supporting stage.
A Multithreaded Scheduler For A High-Speed Simulator, Gene Saghi, Kirk Reinholtz, Paul Savory
A Multithreaded Scheduler For A High-Speed Simulator, Gene Saghi, Kirk Reinholtz, Paul Savory
Department of Industrial and Management Systems Engineering: Faculty Publications
The Cassini spacecraft is on its journey to Saturn to perform a close-up study of the Saturnian system; its rings, moons, magneto-sphere, and the planet itself. Sequences of commands will be sent to the spacecraft by ground personnel to control every aspect of the mission. To validate and verify these command sequences, a bit-level, high-speed simulator (HSS) has been developed. To maximize performance, the HSS is implemented with multiple threads and runs on a multiprocessor system. A key component of the HSS is the scheduler, which controls the execution of the simulator. The general framework of the scheduler can be …
Ds Cdma Scheme For Watm Lan With Error Control, Beata J. Wysocki, Tadeusz A. Wysocki, Hans J. Zepernick
Ds Cdma Scheme For Watm Lan With Error Control, Beata J. Wysocki, Tadeusz A. Wysocki, Hans J. Zepernick
Department of Electrical and Computer Engineering: Faculty Publications (to 2015)
In the paper, we present simulation results for the 13 channel DS CDMA WATM LAN utilising optimized complex spreading signatures based on Walsh- Rademacber functions. The method to obtain those optimized spreading signatures, as well as the full set of the coefficients giving the minimum level of crosscorrelation between any pair of the channels is shown. The resultant system BER as well as the distribution of errors within WATM cells is given. The obtained results indicate that with the application of a hybrid ARQ scheme, capable of correcting 10 errors, the number of WATM cells which would require retransmission is …
Error Performance Of The 13-Channel Ds Cdma Watm Lan, Beata J. Wysocki, Tadeusz Wysocki, Hans J. Zepernick
Error Performance Of The 13-Channel Ds Cdma Watm Lan, Beata J. Wysocki, Tadeusz Wysocki, Hans J. Zepernick
Department of Electrical and Computer Engineering: Faculty Publications (to 2015)
In the paper, we present simulation results for the 13 channel DS CDMA WATM LAN utilising optimized complex spreading signatures based on Walsh-Rademacher functions. The method to obtain those optimized spreading signatures, as well as the full set of the coefficients giving the minimum level of cross-correlation between any pair of the channels is shown. The resultant system BER and the distribution of errors within encapsulated WATM cells is given. The obtained results indicate that with the application of a hybrid ARQ scheme, capable of correcting 10 errors, the number of WATM cells which would require retransmission is in the …