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1998

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Articles 1261 - 1290 of 1354

Full-Text Articles in Engineering

Determination Of Aircraft Orientation For A Vision-Based System Using Artificial Neural Networks, Sanjeev Agarwal, Subhasis Chaudhuri Jan 1998

Determination Of Aircraft Orientation For A Vision-Based System Using Artificial Neural Networks, Sanjeev Agarwal, Subhasis Chaudhuri

Electrical and Computer Engineering Faculty Research & Creative Works

An algorithm for real-time estimation of 3-D orientation of an aircraft, given its monocular, binary image from an arbitrary viewing direction is presented. This being an inverse problem, we attempt to provide an approximate but a fast solution using the artificial neural network technique. A set of spatial moments (scale, translation, and planar rotation invariant) is used as features to characterize different views of the aircraft, which corresponds to the feature space representation of the aircraft. A new neural network topology is suggested in order to solve the resulting functional approximation problem for the input (feature vector)-output (viewing direction) relationship. …


An Efficient, Fast Converging Adaptive Filter For Network Echo Cancellation, Steven L. Grant Jan 1998

An Efficient, Fast Converging Adaptive Filter For Network Echo Cancellation, Steven L. Grant

Electrical and Computer Engineering Faculty Research & Creative Works

This paper discusses a fast efficient adaptive filtering algorithm for network echo cancellers PNLMS++ (proportionate normalized least mean squares ++). Compared to the conventional normalized least mean squares (NLMS) algorithm, PNLMSI++ converges much more quickly when the echo path is sparse. When the echo path is dispersive, the convergence rate is the same as NLMS. In addition, the new algorithm diverges at the same rate and to the same misalignment level as NLMS during periods of undetected double-talk. PNLMS++ is only 50% more computationally complex than NLMS and requires no additional memory


An Analog Vlsi Circuit Implementing An Orthogonal Continuous Wavelet Transform, Dongwei Chen, John G. Harris Jan 1998

An Analog Vlsi Circuit Implementing An Orthogonal Continuous Wavelet Transform, Dongwei Chen, John G. Harris

Electrical and Computer Engineering Faculty Research & Creative Works

We have developed the theory and analog hardware implementation for a Continuous Wavelet Transform (CWT). This novel circuit performs an orthogonal decomposition of temporal signals, such as speech, in a frequency range of 10 Hz to 20 kHz. This multiresolution processor expands the Laguerre structure originally developed by Lee (1960).


1998 Directory Of Indiana State, County, City And Town Officials Responsible For Road And Street Work, Herpicc Jan 1998

1998 Directory Of Indiana State, County, City And Town Officials Responsible For Road And Street Work, Herpicc

Indiana Local Technical Assistance Program (LTAP) Directory

Contact information for agency officials and employees responsible for Indiana’s local road infrastructure.


1998 Bridge Sufficiency Rating Report For All Indiana Counties, Indiana Ltap Jan 1998

1998 Bridge Sufficiency Rating Report For All Indiana Counties, Indiana Ltap

Indiana Local Technical Assistance Program (LTAP) Publications

This is a compilation of the data contained in the individual country reports These reports contain information specific to the county of interest, plus summary tables relating information about all Indiana country bridge conditions and funding levels.


Multiresolution Detection Of Spiculated Lesions In Digital Mammograms, Sheng Liu, Charles F. Babbs, Edward Delp Jan 1998

Multiresolution Detection Of Spiculated Lesions In Digital Mammograms, Sheng Liu, Charles F. Babbs, Edward Delp

Weldon School of Biomedical Engineering Faculty Publications

In this paper we present a novel multiresolution scheme for the detection of spiculated lesions in digital mammograms. First, a multiresolution representation of the original mammogram is obtained using a linear phase nonseparable 2-D wavelet transform. A set of features is then extracted at each resolution in the wavelet pyramid for every pixel. This approach addresses the difficulty of predetermining the neighborhood size for feature extraction to characterize objects that may appear in different sizes. Detection is performed from the coarsest resolution to the finest resolution using a binary tree classifier. This top-down approach requires less computation by starting with …


Formulation Of The Boltzmann Equation As A Multi-Mode Drift-Diffusion Equation, Kausar Banoo, Farzin Assad, Mark S. Lundstrom Jan 1998

Formulation Of The Boltzmann Equation As A Multi-Mode Drift-Diffusion Equation, Kausar Banoo, Farzin Assad, Mark S. Lundstrom

Department of Electrical and Computer Engineering Faculty Publications

We present a multi-mode drift-diffusion equation as reformulation of the Boltzmann equation in the discrete momentum space. This is shown to be similar to the conventional drift-diffusion equation except that it is a more rigorous solution to the Boltzmann equation because the current and carrier densities are resolved into M x 1 vectors, where M is the number of modes in the discrete momentum space. The mobility and diffusion coefficient become M M matrices which connect the M momentum space modes. This approach is demonstrated by simulating electron transport in bulk silicon.


Development Of A 3-D Finite Element Program For Pavement Analysis, Volume I: Introduction And Appendix 1, Tatsaba Nilaward, Chiang Shih, Thomas D. White, E. C. Ting Jan 1998

Development Of A 3-D Finite Element Program For Pavement Analysis, Volume I: Introduction And Appendix 1, Tatsaba Nilaward, Chiang Shih, Thomas D. White, E. C. Ting

JTRP Technical Reports

A three dimensional finite element program is developed for the analysis of pavement systems. An explicit approach of the finite element analysis is adopted. This approach results in a vector formulation of the equation of motion. Large displacement is considered through the use of a co-rotational approach which considers small deformations and large rotations of the elements. For the convenience of application a two dimensional finite element program is also developed. An eight-node ¶metric solid element is used for the three dimensional analysis, and a four-node element for the two dimensional analysis. Loading conditions are verified for static ramp and …


A Dual Agent Approach To Distributed Interactive Simulation Complexity, Barry L. Kelley Jan 1998

A Dual Agent Approach To Distributed Interactive Simulation Complexity, Barry L. Kelley

Link Foundation Modeling, Simulation and Training Fellowship Reports

Distributed Interactive Simulation (DIS) provides a means to create realistic, complex, virtual environments by linking together simulations of various types at multiple locations, and structuring the information exchange between the entities that comprise the simulation. The DIS methodology has demonstrated significant potential for creating virtual worlds that can simulate highly interactive activities. However, as the DIS architecture becomes more complex to support demands for more realistic simulation environments, the data transfer and processing capabilities of the supporting networks and participating simulations become limiting factors in constructing seamless, virtual environments. This document proposes a framework for a Dual Agent Architecture that …


Bs News Jan 1998

Bs News

Building Services Engineering

No abstract provided.


Strength And Durability Of Concrete: Effects Of Cement Paste-Aggregate Interfaces, Part Ii: Significance Of Transition Zones On Physical And Mechanical Properties Of Portland Cement Mortar, Turng-Fang F. Lee, Menashi D. Cohen Jan 1998

Strength And Durability Of Concrete: Effects Of Cement Paste-Aggregate Interfaces, Part Ii: Significance Of Transition Zones On Physical And Mechanical Properties Of Portland Cement Mortar, Turng-Fang F. Lee, Menashi D. Cohen

JTRP Technical Reports

This research was based on a two-part basic research investigation studying the effects of cement paste-aggregate interfaces (or interfacial transition zones-HZ) on strength and durability of concrete. Part I dealt with the theoretical study and Part II dealt with the experimental. Part I, the theoretical part, illustrates the effect of ITZ on the concrete properties by assuming its elastic moduli to be varied continuously in the region. A four-phase composite model is employed and three functions are chosen to model the moduli variation in the ITZ. A theoretical solution for an n-layered spherical inclusion model is used to estimate the …


Recovery Of Intracellular Materials By Electroporation, Wendy Elaine Reid Jan 1998

Recovery Of Intracellular Materials By Electroporation, Wendy Elaine Reid

Theses

Electroporation is commonly used to transfer genetic materials such as DNA into the cell by exposing the cell to a high electric field that momentarily permeabilizes the cell membrane. This premise was utilized to use electroporation as a means of releasing intracellular proteins. A procedure has been developed for the release of intracellular proteins through the use of electroporation. This procedure is a breakthrough. In general, industrial scale techniques to recover proteins from microorganisms are inefficient (Clarkson, 1993). A benefit of this electroporation-based mechanism would be the reduction of steps in the downstream processing required to purify the desired product. …


Determination Of Head Kinematics From Impact Acceleration Test Data Using Neural Networks, Edit J. Kaminsky, Anwer Bashi Jan 1998

Determination Of Head Kinematics From Impact Acceleration Test Data Using Neural Networks, Edit J. Kaminsky, Anwer Bashi

Electrical Engineering Faculty Publications

This paper presents a study of feed-forward neural network (NN) systems developed to determine the head kinematics of subjects who are exposed to impact accelerations. The neural networks process accelerometer data collected during short-duration impact acceleration tests conducted at the National Biodynamcis Laboratory of the University of New Orleans. During an impact acceleration experiment, the subject sits on the sled chair and a piston gives impetus to the sled to travel down a track. Head data is gathered by an array of nine accelerometers. Two more accelerometers are mounted on the sled.

The neural processing systems produce the history of …


A Multithreaded Scheduler For A High-Speed Simulator, Gene Saghi, Kirk Reinholtz, Paul Savory Jan 1998

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 …


A New Radiosonde System For Profiling The Lower Troposphere, Brian R Corner, Robert D. Palmer Jan 1998

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 …


Ds Cdma Scheme For Watm Lan With Error Control, Beata J. Wysocki, Tadeusz A. Wysocki, Hans J. Zepernick Jan 1998

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 Jan 1998

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 …


Optical Determination Of Shallow Carrier Profiles Using Fourier Transform Infrared Ellipsometry, Thomas E. Tiwald, John A. Woollam, John A. Woollam Jan 1998

Optical Determination Of Shallow Carrier Profiles Using Fourier Transform Infrared Ellipsometry, Thomas E. Tiwald, John A. Woollam, John A. Woollam

Department of Electrical and Computer Engineering: Faculty Publications

Dopant profiles were determined by ex situ Fourier transform infrared variable-angle spectroscopic ellipsometry. The technique exploits carrier absorption in the mid-infrared spectral range and combines the sensitivity of ellipsometry with a simple Drude free carrier absorption model to determine the carrier profile. The noncontact, nondestructive nature of the measurement suggests both ex situ and in situ monitoring and control applications. In this study, the carrier profiles were modeled as graded multilayers that can be constrained to a given functional form (Gaussian, erfc, etc.) when desired. Boron and arsenic implanted silicon wafers that were rapid thermal anneal and furnace annealed were …


Missouri River Erosion Update 1941-1998 Yankton Sioux Reservation Marty, South Dakota, Stephen Cournoyer Jr. Jan 1998

Missouri River Erosion Update 1941-1998 Yankton Sioux Reservation Marty, South Dakota, Stephen Cournoyer Jr.

United States Army Corps of Engineers, Omaha District

Pacific GeoScience has completed a revised study of the erosion of Tribal lands (tracts) located along the Missouri River within the yankton Sioux Reservation. This riverbank erosion is related to the construction and operation of Fort Randall Dam. This study evaluated the erosion and accretion of Tribal tracts from 1941 through 1998 (the study period), and estimates the value of the net land eroded as a result of dam construction and operation. This report supersedes the ENVIRON report of 1992 and presents a more comprehensive evaluation of the monetary value of the lost acreage. This study utilizes the current tract …


Production Of Ethers Of Gycerol From Crude Glycerol: The By-Product Of Biodiesel Production, Hossein Noureddini, W. R. Dailey, B. A. Hunt Jan 1998

Production Of Ethers Of Gycerol From Crude Glycerol: The By-Product Of Biodiesel Production, Hossein Noureddini, W. R. Dailey, B. A. Hunt

Papers in Biomaterials

Methyl esters of fatty acids (also known as biodiesel), made from the transesterification of vegetable oils and animal fats with methanol, have shown a lot of promise as alternative diesel fuels. Glycerol is the inevitable by-product of the transesterification process. While there are existing markets for glycerol, a significant increase in availability of glycerol, resulting from the expanded use of vegetable oils and animal fats, would destabilize the glycerol market. Direct addition of glycerol to the fuel is not possible, however, derivatives of glycerol such as ethers have potential for use as additives with biodiesel, diesel or biodiesel-diesel blends. In …


Design Of Tapered Augers For Uniform Unloading Particulate Material From Rectangular Cross-Section Containers, M. S. Burr, Michael F. Kocher, David D. Jones Jan 1998

Design Of Tapered Augers For Uniform Unloading Particulate Material From Rectangular Cross-Section Containers, M. S. Burr, Michael F. Kocher, David D. Jones

Department of Agricultural and Biological Systems Engineering: Faculty Publications

The design equation for an auger to provide uniform unloading of particulate material from a container with a rectangular cross-section (Jones and Kocher, 1995) was revised to account for the minimum flighting height that could effectively unload particles with a known average smallest diameter. A minimum flighting height that was about 64% of the average smallest diameter of the particles was experimentally determined to obtain mean slopes of the top surface of the material not significantly different from zero for screened soybeans. A linear taper that best fit the square root curve for the inside diameter of the auger was …


Matrix-Enhanced Calibration Procedure For Multivariate Calibration Models With Near-Infrared Spectra, Mark R. Riley, Mark A. Arnold, David W. Murhammer Jan 1998

Matrix-Enhanced Calibration Procedure For Multivariate Calibration Models With Near-Infrared Spectra, Mark R. Riley, Mark A. Arnold, David W. Murhammer

Department of Agricultural and Biological Systems Engineering: Faculty Publications

A novel method is introduced for developing calibration models for the spectroscopic measurement of chemical concentrations in an aqueous environment. To demonstrate this matrix-enhanced calibration procedure, we developed calibration models to quantitate glucose and glutamine concentrations in an insect cell culture medium that is a complex mixture of more than 20 components, with three components that manifest significant concentration changes. Accurate calibration models were generated for glucose and glutamine by using a calibration data set composed of 60 samples containing the analytes dissolved in an aqueous buffer along with as few as two samples of the analytes dissolved in culture …


Biodiesel Fuel From Animal Fat. Ancillary Studies On Transesterification Of Beef Tallow, Fangrui Ma, L. Davis Clements, Milford Hanna Jan 1998

Biodiesel Fuel From Animal Fat. Ancillary Studies On Transesterification Of Beef Tallow, Fangrui Ma, L. Davis Clements, Milford Hanna

Nebraska Center for Biotechnology: Faculty and Staff Publications

Transesterification of beef tallow was investigated. The solubility of ethanol in beef tallow was much higher than that of methanol. At 100 °C the solubility of methanol was 19% (w/w). The solubility of ethanol in beef tallow reached 100% (w/w) at about 68 °C. For the distribution of methanol between beef tallow methyl esters (BTME) and glycerol, the percentage of total methanol in the glycerol phase was higher than that in the fatty acid methyl ester (FAME) phase in a simulated system at room temperature. At 65-80 °C, however, the percentage of total methanol in FAME (60% (w/w)) was higher …


Electrochemical Investigations Of Cobalt-Doped Limn2O4 As Cathode Material For Lithium-Ion Batteries, P. Arora, Branko Popov, Ralph E. White Jan 1998

Electrochemical Investigations Of Cobalt-Doped Limn2O4 As Cathode Material For Lithium-Ion Batteries, P. Arora, Branko Popov, Ralph E. White

Faculty Publications

A wide range (y = 0.05–0.33) of Co-doped LiCoyMn2–yO4 spinels were synthesized and electrochemically characterized. These Co-doped spinels showed improved specific capacity and capacity retention over pure spinels. Electrochemical impedance spectroscopy and the linear polarization resistance technique were used to determine the transport and electrochemical kinetic parameters of Co-doped spinels. The presence of Co in the spinel inhibits the passivation process occurring on the surface of the cathode. Also, Co increases the exchange current density and facilitates the charge-transfer reaction of the active material. The lower self-discharge observed for Co-doped spinels was attributed …


Characterization Of Hydrogen Permeation Through Zinc-Nickel Alloys Under Corroding Conditions: Mathematical Model And Experimental Study, M. Ramasubramanian, Branko N. Popov, Ralph E. White Jan 1998

Characterization Of Hydrogen Permeation Through Zinc-Nickel Alloys Under Corroding Conditions: Mathematical Model And Experimental Study, M. Ramasubramanian, Branko N. Popov, Ralph E. White

Faculty Publications

A mathematical model was developed for the characterization of hydrogen permeation into metals and alloys under corroding conditions. The model requires a knowledge of the corrosion rate of the given metal or alloy in solutions of various H+ concentrations. It provides quantitative values of rate constants of the hydrogen discharge, recombination, and adsorption reactions. This model can serve as a diagnostic criterion for determining the effectiveness of various metals and alloys as hydrogen permeation inhibitors and can be used for evaluation of hydrogen entry inhibition efficiency. Experiments were carried out to study the effectiveness of thin layers of electrodeposited …


Characterization Of Sol-Gel-Derived Cobalt Oxide Xerogels As Electrochemical Capacitors, Chuan Lin, James A. Ritter, Branko N. Popov Jan 1998

Characterization Of Sol-Gel-Derived Cobalt Oxide Xerogels As Electrochemical Capacitors, Chuan Lin, James A. Ritter, Branko N. Popov

Faculty Publications

Very fine cobalt oxide xerogel powders were prepared using a unique solution chemistry associated with the sol-gel process. The effect of thermal treatment on the surface area, pore volume, crystallinity, particle structure, and corresponding electrochemical properties of the resulting xerogels was investigated and found to have significant effects on all of these properties. The xerogel remained amorphous as Co(OH)2 up to 160°C, and exhibited maxima in both the surface area and pore volume at this temperature. With an increase in the temperature above 200°C, both the surface area and pore volume decreased sharply, because the amorphous Co(OH)2 decomposed …


Studies On Electroless Cobalt Coatings For Microencapsulation Of Hydrogen Storage Alloys, Bala S. Haran, Branko N. Popov, Ralph E. White Jan 1998

Studies On Electroless Cobalt Coatings For Microencapsulation Of Hydrogen Storage Alloys, Bala S. Haran, Branko N. Popov, Ralph E. White

Faculty Publications

LaNi4.27Sn0.24 alloy was microencapsulated with cobalt by electroless deposition from an alkaline hypophosphite bath. Discharge curves of the encapsulated alloy indicate an additional contribution to the capacity arising from the cobalt on the surface. Studies on cobalt thin films reveal the presence of adsorbed hydrogen in cobalt. The amount of hydrogen adsorbed was observed to increase with time of cathodic polarization and to reach a maximum. Polarization techniques have been used to characterize the cobalt-plated alloy as a function of state of charge. The equilibrium potential of the microencapsulated electrode at low hydrogen concentration is determined by …


Theoretical Analysis Of Metal Hydride Electrodes: Studies On Equilibrium Potential And Exchange Current Density, Bala S. Haran, Branko N. Popov, Ralph E. White Jan 1998

Theoretical Analysis Of Metal Hydride Electrodes: Studies On Equilibrium Potential And Exchange Current Density, Bala S. Haran, Branko N. Popov, Ralph E. White

Faculty Publications

A theoretical model for the metal hydride electrode has been developed assuming that hydrogen diffusion in the alloy and charge-transfer at the surface control the discharge process. Theoretical equations for the dependence of equilibrium potential and exchange current density on the surface hydrogen concentration have been derived. These parameters have been used to correlate experimental data with the theoretical electrode discharge model. Analysis of both the experimental and theoretical discharge curves reveals a potential plateau determined by the magnitude of the interactions between the hydrogen in the alloy and the unhydrided metal. Neglecting these hydrogen-metal site interactions results in simulations …


A Nonisothermal Nickel‐Hydrogen Cell Model, Pauline De Vidts, Javier Delgado, B. Wu, D. M. See, K. Kosanovich, Ralph E. White Jan 1998

A Nonisothermal Nickel‐Hydrogen Cell Model, Pauline De Vidts, Javier Delgado, B. Wu, D. M. See, K. Kosanovich, Ralph E. White

Faculty Publications

No abstract provided.


The Role Of Oxygen At The Second Discharge Plateau Of Nickel Hydroxide, Sathya Motupally, Mukul Jain, Venkat Srinivasan, John W. Weidner Jan 1998

The Role Of Oxygen At The Second Discharge Plateau Of Nickel Hydroxide, Sathya Motupally, Mukul Jain, Venkat Srinivasan, John W. Weidner

Faculty Publications

It was shown that the appearance of a secondary discharge plateau approximately 400 mV below the primary plateau can result from the reduction of oxygen. During the galvanostatic discharge of planar nickel-hydroxide films at room temperature and in 3 weight percent KOH solutions, the second discharge plateau was observed only in the presence of dissolved oxygen in the electrolyte. When the solution was deoxygenated, no residual capacity could be extracted from the films even at low discharge rates or from overcharged films. In addition, the duration of the second plateau is inversely proportional to the square of the discharge current, …