Electrical and Computer Engineering Commons^™

Time Domain Dielectric Spectroscopy Analysis Of Hl-60 Cell Suspensions After Microsecond And Submicrosecond Pulsed Electric Fields, Allen Laurence Garner

Electrical & Computer Engineering Theses & Dissertations

Pulsed electric fields (PEF's) above a certain voltage threshold cause electroporation for microsecond pulses and intracellular effects for submicrosecond pulses. Models describing these effects often depend on the electrical properties of the cell, which are altered by the PEF. Time domain dielectric spectroscopy was used to provide data for these models and to measure changes in the conductivity of HL-60 cell suspensions due to single 50 μs and 10 ns PEF's of the same energy. For 1.1 kV/cm, 50 μs pulses, the conductivity rose within a minute after the pulse and dropped dramatically approximately forty minutes after the pulse. For …

Unidirectional Cordic For Efficient Computation Of Trigonometric And Hyperbolic Functions, Satish Ravichandran

Electrical & Computer Engineering Theses & Dissertations

CORDIC (Coordinate Rotation Digital Computer) is an iterative algorithm to compute values of trigonometric, logarithmic and transcendental functions by performing vector rotations, which can be implemented with only shift and add operations in a digital system. CORDIC algorithms are extensively used in the areas of digital signal processing, digital image processing and artificial neural networks. A new technique, named unidirectional CORDIC, for efficient computation of trigonometric and hyperbolic functions is presented in this thesis. In the conventional CORDIC algorithm, the vector rotations are performed in both clockwise and counterclockwise directions, but in the unidirectional CORDIC the vectors are rotated only …

Seven Principles Of Efficient Human Robot Interaction, Michael A. Goodrich, Dan R. Olsen Jr.

Faculty Publications

Advances in robot technology and artificial intelligence have increased the range of robot applications as well as the importance of supporting human interaction with robots and robot teams. Previous work by the authors has highlighted the importance of creating neglect tolerant autonomy and efficient interfaces. In this paper, lessons learned from evaluating neglect tolerance and interface efficiency are compiled into a set of principles for efficient interaction. Emphasis is placed on designing efficient interfaces, but many of the principles require autonomy levels that support the principles. Each principle is illustrated by an example and motivated by citing relevant factors from …

The Effect Of Pruning And Compression On Graphical Representations Of The Output Of A Speech Recognizer, Yang Liu, Mary P. Harper, Michael T. Johnson, Leah H. Jamieson

Electrical and Computer Engineering Faculty Research and Publications

Large vocabulary continuous speech recognition can benefit from an efficient data structure for representing a large number of acoustic hypotheses compactly. Word graphs or lattices have been chosen as such an efficient interface between acoustic recognition engines and subsequent language processing modules. This paper first investigates the effect of pruning during acoustic decoding on the quality of word lattices and shows that by combining different pruning options (at the model level and word level), we can obtain word lattices with comparable accuracy to the original lattices and a manageable size. In order to use the word lattices as the input …

Remote Monitoring Of Repository Integrity Using Passive Seismic Arrays, Barbara Luke, Evangelos Yfantis

Publications (YM)

Once radioactive waste is emplaced in the repository, the challenge of monitoring the continued integrity of the excavated openings (e.g., emplacement drifts) escalates tremendously. We envision a seismic monitoring array installed on the surface at Yucca Mountain, which operates automatically to monitor repository opening stability in the long term. The objective is to monitor and validate the structural integrity of the emplacement drifts through identifying and localizing rock falls that could compromise drift access, hinder waste retrievability, and potentially reduce the effective life of waste canisters. Collateral benefits of the system include the ability to address some outstanding uncertainties regarding …

Line Detection Using Wavelet Filters, Somkait Udomhunsakul, Samuel Peter Kozaitis, Uthai Thai Sritheeravirojana, A. Khempila

Electrical Engineering and Computer Science Faculty Publications

We proposed a new line detection method in noisy images using Mexican hat wavelet filters. In our approach, we applied the wavelet transform in a multiresolution sense by forming the products of wavelet coefficients at the different scales to locate and identify lines at different scales. In addition, we also considered shifting line locations through multiple scales for robust line detection in the presence of noise. We found that our approach leads to an effective method to form the basis of a line detection approach.

Theory, Design, And Fabrication Of Diffractive Grating Coupler For Slab Waveguide, Kevin Randolph Harper

Theses and Dissertations

This thesis presents the theory design and fabrication of a diffractive grating coupler. The first part of the design process is to choose the period of the grating coupler based on the desired coupling angle. The second part of the design process is to choose the geometry of the grating that gives maximum coupling efficiency based on rigorous analyses.

The diffraction gratings are fabricated by recording the interference between two waves in photoresist. The waveguide is fabricated from silicon nitride that is deposited by chemical vapor deposition. The diffraction grating recording assembly is described along with the grating coupler fabrication …

A Practical Experience About Dynamic Performance And Stability Improvement Of Synchronous Generators, Chi-Jui Wu, Yung-Sung Chuang

Journal of Marine Science and Technology–Taiwan

This paper describes the practical experiences about the no-load dynamic performance test, parameter identification, and tuning of static excitation systems (SESs) of the synchronous generators in the Tong-Shiao Generation Station of the Taiwan Power System. The dynamic stability of under-load generators has also been improved. The hardware circuits of SESs had been modified. This caused the detuning of parameter values, so that the generators did not have enough ability to sustain voltage fluctuation disturbances. Several SESs had been preliminarily retuned according to the results from simple field tests. However, step signal responses in field tests revealed that the characteristics of …

Reduction Of Multiplicative Noise Using Higher-Order Statistics, Samuel Peter Kozaitis, Anurat Ingun, Rufus H. Cofer

Electrical Engineering and Computer Science Faculty Publications

We used a higher-order correlation-based method for signal denoising of images corrupted by multiplicative noise. Using the logarithm of an image, we applied a third-order correlation technique for identification of wavelet coefficients that contained mostly signal. In our approach, we examined wavelet coefficients in an environment where the contribution from the second-order moment of the noise had been reduced. Our results compared favorably and were less sensitive to threshold selection when compared to a second-order wavelet denoising method.

Evaluating Tmr Techniques In The Presence Of Single Event Upsets, Paul S. Graham, Nathaniel Rollins, Michael J. Wirthlin, Michael P. Caffrey

Faculty Publications

Sponsorship: Los Alamos National Labs (LA-UR-03-7525). Field programmable gate arrays (FPGAs) are sensitive to radiation-induced single event upsets (SEUs) within the configuration memory. Triple modular redundancy (TMR) is a technique commonly used to mitigate against design failures caused by SEUs. This paper evaluates the effectiveness and cost of TMR on two different counter designs in the presence of SEUs. The evaluation measures the reliability, area cost, and speed of different TMR styles. The tests show that when feedback TMR is used with triplicated clocks, it is possible to have counter design which is insensitive to any single configuration upset.

Deterministic Surface Registration At 10hz Based On Landmark Graphs With Prediction, Fred W. Depiero

Electrical Engineering

Landmark graphs provide a means for surface registration, based on determining subgraph isomorphism to find scene-to-scene correspondences. Surface data used herein included both range and colour imagery. Images were acquired of a static scene from a moving sensor. The continuous motion allowed the sensor position to be predicted, which helped stabilize graph formation. Landmarks were determined using the KLT corner detector. Graph structure was established using nodes (landmarks) and edges that agreed well with predicted locations. Subgraph matching was approximated using the LeRP algorithm. A 6 DOF rigid transformation including translation and rotation was found via Horn’s method. Test results …

Surface Registration At 10hz Based On Landmark-Graphs: Benefits For A Scalable Remote Viewing System, Fred W. Depiero

Electrical Engineering

Real-time surface registration is a key technology for the development of future remote viewing systems. An architecture for a video distribution system supporting multiple users, with individual viewpoint selection, is suggested. The approach would provide a transmission bandwidth independent of the number of users, for scalability. The proposed architecture uses a method of surface registration based on landmark-graphs. Results from 141 test trials on synthetic scenes indicate that a mean absolute positioning accuracy under 1% of the sensor field of view is possible. The mean rate for registration was 10Hz, with a standard deviation under 10%. Tests were benchmarked on …

The Estimation And Control Of A Laboratory Heating And Ventilation System, Robin P. Mooney

Masters in Advanced Engineering

This dissertation is concerned with the estimation and control of a laboratory heating and ventilation system (Instrutek VVS-400). The system is a 2x2 multi-input multi-output process (MIMO). It has been shown that simple techniques such as the ultimate cycle method do not provide adequate control of the process. The system was interfaced with a PC using Matlab/Simulink via a data acquisition package (Humusoft). Continuous time process identification techniques were applied to the flow and temperature processes. The alternative tangent and point method was used to model the processes, and their interaction, using a first order lag plus delay model. Models …

Identification And Pid Control Of Time-Delayed Processes, Tony Kealy

Masters

This research was conducted primarily to investigate a selection of known methods for the identification of a mathematical model for processes with an inherent time delay, and subsequently, use the parameters of the identified model to regulate the processes via the PI/PID control strategy. The research examines the level of difficulty in performing or sanctioning different system identification methods in order to re-tune the controller. The process model identification methods are carried out on both simulated and real processes in the first part of the research. The selected parametric identification methods are chosen because they encompass open- and closed- loop …

Modified Fast Inhomogeneous Plane Wave Algorithm From Low Frequency To Microwave Frequency, L. (Lijun) J. Jiang, W. C. Chew

Electrical and Computer Engineering Faculty Research & Creative Works

A new method, MFIPWA, is proposed to extend the traditional MLFMA and FIPWA into the low frequency range. It uses the evanescent-wave extrapolation and translation techniques to overcome the low-frequency breakdown problem. The accuracy can be well controlled over a broad frequency range.

Comparison Of Process Identification Techniqies In The Time- And Frequency-Domains, Tony Kealy, Aidan O'Dwyer

Conference papers

This paper describes ten methods to identify a mathematical model for a real process with a time delay. The process is the Process Trainer, PT326 from Feedback Instruments Limited. Six of the methods use step response data and one of the methods uses impulse response data for identification. Two of the methods use frequency response data and the final method uses information from relay-based experiments. The best results are obtained using a combined analytical and gradient method [6] in the frequency-domain and, in the time-domain, using the two-point algorithm [1] and a method proposed by Suganda et al. [5].

Autonomous Vehicle Technologies For Small Fixed Wing Uavs, Derek B. Kingston, Randal Beard, Timothy Mclain, Michael Larsen, Wei Ren

Faculty Publications

Autonomous unmanned air vehicle flight control systems require robust path generation to account for terrain obstructions, weather, and moving threats such as radar, jammers, and unfriendly aircraft. In this paper, we outline a feasible, hierarchal approach for real-time motion planning of small autonomous fixed-wing UAVs. The approach divides the trajectory generation into four tasks: waypoint path planning, dynamic trajectory smoothing, trajectory tracking, and low-level autopilot compensation. The waypoint path planner determines the vehicle's route without regard for the dynamic constraints of the vehicle. This results in a significant reduction in the path search space, enabling the generation of complicated paths …

Dcim-Accelerated Smfma For Capacitance Extraction, L. (Lijun) J. Jiang, W. C. Chew, Y. C. Pan

Electrical and Computer Engineering Faculty Research & Creative Works

A new method to evaluate the SMFMA translators and near-field interactions for the capacitance extraction of the complicated structures in the multilayer medium is presented. As such, the spherical harmonic functions are extended into the complex plane to derive the closed forms of all multipole translators. This new technique can make the SMFMA setup stage one to two-orders faster compared to the old method. Moreover, it provides excellent accuracy with little computation costs.

One-Layer Neural-Network Controller With Preprocessed Inputs For Autonomous Underwater Vehicles, Sarangapani Jagannathan, Gustavo Galan

Electrical and Computer Engineering Faculty Research & Creative Works

Navigating, guiding, and controlling autonomous underwater vehicles (AUVs) are challenging and difficult tasks compared to the autonomous surface-level operations. Controlling the motion of such vehicles require the estimation of unknown hydrodynamic forces and moments and disturbances acting on these vehicles in the underwater environment. in this paper, a one-layer neural-network (NN) controller with preprocessed input signals is designed to control the vehicle track along a desired trajectory, which is specified in terms of desired position and attitude. in the absence of unknown disturbances and modeling errors, it is shown that the tracking error system is asymptotically stable. in the presence …

A Novel Method For Measuring Induction Machine Magnetizing Inductance, Ana Vladan Stankovic, Eric L. Benedict, Vinod John, Thomas A. Lipo

Electrical and Computer Engineering Faculty Publications

This paper presents a novel method for measuring the magnetizing inductance of an induction machine. The approach uses a static DC excitation technique which can be employed whenever the neutral of the machine is accessible. The proposed method measures only the magnetizing inductance and not the self inductance which normally includes the effect of the stator leakage inductance. Because this test uses a DC excitation, the iron losses in the motor are considerably reduced as well and minimally influence the measurement when compared to the traditional 60-Hz no-load test. By using the proposed method for measuring only the magnetizing inductance, …

Adaptive Reflex Control For An Artificial Hand, Michele Flogheraiter, Giuseppina Gini, Marek Perkowski, Mikhail Pivtoraiko

Electrical and Computer Engineering Faculty Publications and Presentations

In this paper we illustrate the properties and the morphology of a human like neural reflex controller, used to set the stiffness and joint positions of an anthropomorphic artificial hand. In particular we explain, by simulations results, its ability to emulate the myotatic human reflex, and its capacity to learn in real time the best control strategy. We also present the dynamic model of the joints and of the artificial muscles used in Blackfingers, our artificial hand.

Mobility Modeling And Management For Next Generation Wireless Networks, Woo-Jin Choi

Dissertations

Mobility modeling and management in wireless networks are the set of tasks performed in order to model motion patterns, predict trajectories, get information on mobiles' whereabouts and to make use of this information in handoff, routing, location management, resource allocation and other functions.

In the literature, the speed of mobile is often and misleadingly referred to as the level of mobility, such as "high" or "low" mobility. This dissertation presents an information theoretic approach to mobility modeling and management, in which mobility is considered as a measure of uncertainty in mobile's trajectory, that is, the mobility is low if the …

Capacity, Coding And Interference Cancellation In Multiuser Multicarrier Wireless Communications Systems, Christian Ibars Casas

Dissertations

Multicarrier modulation and multiuser systems have generated a great deal of research during the last decade. Orthogonal Frequency Division Multiplexing (OFDM) is a multicarrier modulation generated with the inverse Discrete Fourier Transform, which has been adopted for standards in wireless and wire-line communications. Multiuser wireless systems using multicarrier modulation suffer from the effects of dispersive fading channels, which create multi-access, inter-symbol, and inter-carrier interference (MAI, ISI, ICI). Nevertheless, channel dispersion also provides diversity, which can be exploited and has the potential to increase robustness against fading. Multiuser multi-carrier systems can be implemented using Orthogonal Frequency Division Multiple Access (OFDMA), a …

Performance Evaluation For Communication Systems With Receive Diversity And Interference, Debang Lao

Dissertations

Optimum combining (OC) is a well-known coherent detection technique used to combat fading and suppress cochannel interference. In this dissertation, expressions are developed to evaluate the error probability of OC for systems with multiple interferers and multiple receiving branches. Three approaches are taken to derive the expressions. The first one starts from the decision metrics of OC. It facilitates obtaining closed-form expressions for binary phase-shift keying modulation. The second approach utilizes the moment generating function of the output signal to interference plus noise ratio (SINR) and results in expressions for symbol and bit error probability for multiple phaseshift keying modulation. …

Method For Theoretically Determining The Locus And Location Of The Transmission Zeros In Microwave Filter Networks, Keehong Um

Dissertations

This dissertation presents a theoretical investigation of a practical method to determine quantitatively the locations and loci of complex transmission zeros (TZ's) of positively and negatively cross-coupled RF or microwave bandpass filter networks.

Bandpass filters can be effectively designed by adjusting the locations of TZ's in the complex s-domain. To locate TZ's, this practical method uses chain matrices for subsystems (discrete parts of the network) of the filter network, and can be extended to other types of filters with cross-coupled sections.

An important result is that a complex doublet, triplet and/or quadruplet, (one-, two-, or four-pairs) of TZ's are shown …

Photonic Crystals Composed Of Thick Inductive And Capacitive Meshes, Jay Shah

Theses

The transmission properties of metal meshes are studied for single meshes, photonic double layers and photonic crystals. Simulations are performed with the Flomerics Micro-Stripes program for light of infrared and millimeter wavelengths. The Micro-Stripes program solves Maxwell's equations numerically and, for simulations of the transmittance of metal meshes, has been proven as good as an experiment. Input data are the geometrical parameters, the indices of refraction and the conductivity, chosen according to the Drude model. The light is assumed to be at normal incidence and the simulation results are compared with experiments.

Single layers of inductive meshes are studied for …

Transport Properties Of Nc-Si / A-Sio2 Superlattices And Their Applications In Non-Volatile Memory, Lakshmi Susmitha Koneru

Theses

The dc current-voltage characteristics, ac conductivity, equivalent capacitance, photocurrent transients of the n-Si/nanocrystalline-Si/amorphous-SiO₂/Al heterostructure were measured in a wide range of illumination intensities for temperatures from 4.2 K to 300 K. Electrical transport properties of the nanocrystalline-Si/amorphous-SiO₂ superlattices were discussed. The observed domination of the electron component at negative bias and of the hole component at positive bias above 0.7 V in a dc current allows to separate transport features of electrons and holes in a nc-Si/a-SiO₂ superlattices. Transport of electrons is thermally activated if potential barrier at c-Si/SL interface of 70 meV is suppressed and …

Elastic Brain Image Registration Using Mutual Information, Srisheela Devabhaktuni

Theses

Image Registration is the determination of a geometrical transformation that aligns points in one image of an object with corresponding points in another image. The source image is geometrically transformed to match the target image. The geometric transformation can be rigid or non-rigid. Rigid transformations preserve straight lines and angles between straight lines. The basic rigid transformations are rotation, scaling and translation.

In this thesis non-rigid registration using B-splines is the method being used to take into account the elastic change in the brain structure. The B-spline equation is a type of curved transformation that does not preserve the straightness …

Deposition And Characterization Of Laser-Ablated Silicon, Wenwen Luo

Theses

Laser ablation is a powerful thin film deposition and material processing technology. In the Nonlinear Nanostructure Lab at NJIT, silicon films deposited by laser ablation have been studied for the potential applications in nonlinear optoelectronic devices. The previous studies have suggested that the deposited silicon has a hexagonal symmetry, being a polymorph of silicon that previously has been obtained only at very high pressure. This thesis is part of the continuous study and characterization of this new structure. The objective of the research was to gain better understanding of the hexagonal silicon properties as well as the mechanism that lead …

Service Differentiation In Multihop Wireless Packet Networks, Ilker Onat

Theses

This work explores the potential of link layer scheduling combined with MAC layer prioritization for providing service differentiation in multihop wireless packet networks. As a result of limited power, multihop characteristic and mobility, packet loss ratio in wireless ad hoc networks tends to be high compared to wireline and one-hop mobile data networks. Therefore, for wireless ad hoc networks, DiffServ-like distributed service differentiation schemes are more viable than hard QoS solutions, which are mainly designed for wireline networks. The choice and implementation of proper queuing and scheduling methods, which determine how packets will use the channel when bandwidth becomes available, …