Digital Commons Network^™

Pixel-Registered Image Fusion, Rufus H. Cofer, Samuel Peter Kozaitis

Electrical Engineering and Computer Science Faculty Publications

One of the highest potential uses of image fusion is that of recognition of critical targets. The continuing image fusion question then is how to make optimal use of the often disparate forms of encountered image detail during fusion. Toward this end, many techniques have been advanced for fusion to a single viewable image. Fewer techniques have been suggested toward fusion with the goal of directly improving target detection or recognition. Based upon emerging trends in pixel accurate registration of images, we show the theoretical foundations required to optimally fuse target imagery for recognition. Results obtained can be applied to …

Generalized Beam Matrices: Gaussian Beam Propagation In Misaligned Complex Optical Systems, Anthony A. Tovar, Lee W. Casperson

Electrical and Computer Engineering Faculty Publications and Presentations

A novel 3 × 3 transfer-matrix method is developed to propagate off-axis Gaussian beams in astigmatic optical systems that may include tilted, displaced, or curved optical elements. Unlike in a previous generalized ray matrix formalism, optical elements that possess gain or loss such as Gaussian apertures, complex lenslike media, and amplifiers are included; and a new beam transformation is found. In addition, a novel exponential variable-reflectivity mirror, which displaces a Gaussian beam without changing its spot size, and a complex prismlike medium are introduced.

Fault Tolerant Pipelined Adaptive Systems, Bhasker Reddy Allam

Electrical & Computer Engineering Theses & Dissertations

A fault tolerant pipelined architecture for high sampling rate adaptive filters is presented in this thesis. The architecture is based on the computational requirements of delayed LMS and lattice adaptive 61ters. It offers robust performance in the presence of single hardware faults, and software faults resulting from numerical instability. Two different architectures are proposed. One allows a graceful degradation in system performance in the event of a fault, and the other uses a module replacement strategy to recover from faults without decreasing performance. Analysis of the steady state error increase due to filter reconfiguration is presented. The reliability of the …

Comparison Of System Identification Techniques For The Dexterous Orbital Servicing System (Doss), Allan Terrence Morris

Electrical & Computer Engineering Theses & Dissertations

The major contribution of system identification is the development of analytical models of a system. Many identification techniques can adequately describe the input and output map. One of the challenges of these techniques is to correctly infer from the measured data the characteristics of the individual, contributing components producing a more accurate system model.

In this thesis linear, dynamic, multivariable state-space models for three joints of the Dexterous Orbital Servicing System (DOSS) are identified. DOSS is a representative space station manipulator at the NASA Langley Research Center. The dynamic models of the manipulator will first be estimated by applying nonparametric …

Design, Fabrication, Modeling, And Testing Of Surface-Micromachined Micromirror Devices, M. Adrian Michalicek

Theses and Dissertations

The Flexure-Beam Micromirror Device (FBMD) is a phase-only piston style spatial light modulator demonstrating properties which can be used for phase adaptive- corrective optics. This thesis presents a complete study of new designs of FBMDs and other micromirror devices, from original design considerations through final device testing and verification of ideal and advanced models. The models relate the electrical and mechanical properties of the device by equating the electrostatic force of a parallel- plate capacitor with the counteracting spring force of the device's support flexures. For the advanced model of the Flexure-Beam micromirror device, the capacitor solution is derived via …

Determination Of The Temperature Coefficients Of Selected Material Constants Of Dilithium Tetraborate, Gregory S. Weaver

Theses and Dissertations

The first and second order temperature coefficients of the material constants c^E₁₁, c^E₁₂, c^E₄₄, c^E₆₆, and e¹⁵ of dilithium tetraborate (Li₂B₄O₇) have been measured over a temperature range of 20°C to 150°C. An improved resonator method was used to measure the fundamental zero mass loading antiresonant frequencies of selected pure-mode orientations of Li₂B₄O₇. Material constants extraction was performed using a linear least squares matrix method. The resulting material constant curves were fit with a third …

Design And Development Of Microswitches For Micro-Electro-Mechanical Relay Matrices, Mark W. Phipps

Theses and Dissertations

Many different micro-electro-mechanical switches were designed in the Multi-User MEMS processes (MUMPs) and deep x-ray lithography and electroforming (LIGA) processes. The switches were composed of actuators that operated based upon either electrostatic forces or thermal forces. A thermally activated beam flexure actuator that operated based upon differential heating was used extensively. This actuator, which was fabricated in the MUMPs process, was able to deflect up to 12 microns with a total input power of less than 25 mW. The thermal resistance, which was needed to model this actuator, was determined from a material constant, 1.9 ± 0.08 m^1.5-°C-W …

Fuzzy Logic For Digital Phase-Locked Loop Filter Design, Daniel J. Simon, Hossny El-Sherief

Electrical and Computer Engineering Faculty Publications

The problem of robust phase-locked loop design has attracted attention for many years, particularly since the advent of the global positioning system. This paper proposes and demonstrates the use of a fuzzy PLL to estimate the time-varying phase of a sinusoidal signal. It is shown via simulation results that fuzzy PLL's offer performance comparable to analytically derived PLL's (e.g. Kalman filters and H_∞ estimators) when the phase exhibits high dynamics and high noise. The fuzzy PLL rules are optimized using a gradient descent method and a genetic algorithm

Identification And Evaluation Of Monitoring Techniques For The Performance Of A Communication Network, Maureen E. Borgia

Theses and Dissertations

This study investigates the application of statistical process control methods to monitoring the performance of a communication network. The methods applied include four different types of control charts. The literature search uncovered only one previous study that used a control chart to monitor a communication network. Using a case study of a communication network, four important issues for proper control chart usage are emphasized. These issues are: proper data collection rate due to autocorrelation, proper subgrouping of the data, ensuring that count data conforms to the assumptions of the binomial probability model before implementing p or np control charts, and …

Navigation Satellite Selection Using Neural Networks, Daniel J. Simon, Hossny El-Sherief

Electrical and Computer Engineering Faculty Publications

The application of neural networks to optimal satellite subset selection for navigation use is discussed. The methods presented in this paper are general enough to be applicable regardless of how many satellite signals are being processed by the receiver. The optimal satellite subset is chosen by minimizing a quantity known as Geometric Dilution of Precision (GDOP), which is given by the trace of the inverse of the measurement matrix. An artificial neural network learns the functional relationships between the entries of a measurement matrix and the eigenvalues of its inverse, and thus generates GDOP without inverting a matrix. Simulation results …

On Primitive Bch Codes With Unequal Error Protection Capabilities, Robert H. Morelos-Zaragoza, Shu Lin

Faculty Publications

Presents a class of binary primitive BCH codes that have unequal-error-protection (UEP) capabilities. The authors use a previous result on the span of their minimum weight vectors to show that binary primitive BCH codes, containing second-order punctured Reed-Muller (RM) codes of the same minimum distance, are binary-cyclic UEP codes. The values of the error correction levels for this class of binary LUEP codes are estimated.

Visible Light Emitting Diodes Fabricated From Soluble Semiconducting Polymers, Alan J. Heeger, David Braun

Electrical Engineering

Visible light LEDs are produced having a layer of conjugated polymer which is cast directly from solution or formed as a gel-processed admixture with a carrier polymer. The LEDs can be formed so as to emit polarized light.

Hardware/Software Codesign And Simulation With The Occam Programming Language, Roy L. Krans

Masters Theses

Hardware/software codesign is an increasingly popular method for improving system performance and adaptability while minimizing cost. The goal of this design approach is to achieve the desired system characteristics (performance, fault tolerance, cost, power consumption, etc.) by carefully distributing the system functions among hardware and software components. Popular tools for describing this dual hardware/software functionality are behavioral languages such as C++ and Ada. These languages typically include facilities for both traditional sequential programming as well as behavioral modeling.

This thesis examines the effectiveness of occam as a behavioral language and its role in hardware/software codesign. The occam language is used …

Optical Constants Of GaXIn1-XP Lattice Matched To Gaas, Mathias Schubert, V. Gottschalch, Craig M. Herzinger, Huade Yao, Paul G. Snyder, John A. Woollam

Department of Electrical and Computer Engineering: Faculty Publications

The optical constants of Ga_0.51In_0.49P have been determined from 0.8 to 5.0 eV using variable-angle spectroscopic ellipsometry measurements at room temperature. The metal-organic vapor-phase-epitaxy-grown samples were x-ray analyzed to confirm lattice matching to the GaAs substrate. The effects of the native oxide were numerically removed from the data to determine the intrinsic optical constants. This is important because the optical constants reported become generally useful for modeling multiple-layer structures. A Kramers-Kronig analysis was used to reduce interference-related fluctuations in the below-gap refractive index. Near the band edge a mathematical form for excitonic absorption was included. Critical …

Gps Modeling For Designing Aerospace Vehicle Navigation Systems, John J. Dougherty, Hossny El-Sherief, Daniel J. Simon, Gary A. Whitmer

Electrical and Computer Engineering Faculty Publications

The complexity of the design of a Global Positioning System (GPS) user segment, as well as the performance demanded of the components, depends on user requirements such as total navigation accuracy. Other factors, for instance the expected satellite/vehicle geometry or the accuracy of an accompanying inertial navigation system can also affect the user segment design. Models of GPS measurements are used to predict user segment performance at various levels. Design curves are developed which illustrate the relationship between user requirements, the user segment design, and component performance.

Fetal Heart Rate Detection With A Passive Acoustic Sensor System, Zongyao Zhou

Electrical & Computer Engineering Theses & Dissertations

Research and development is presented of real time signal processing methodologies for the detection of fetal heart tones from noise contaminated signals obtained from passive acoustic sensors. A nonlinear Teager energy operator is utilized for detection of the fetal heart tone event. Autocorrelation and a parallel redundancy correction algorithm derives fetal heart rates. A real time monitoring system is described which records and plots the time history of both the fetal heart rate and the acoustic fetal heart signal. The system is validated in the context of the fetal nonstress test. Comparisons are made with ultrasonic nonstress tests on a …

Fiber Optic Detector And Depth Sensor And Method For Doing Same, Lawrence W. Evers, Kenneth J. Jackson

Michigan Tech Patents

A fiber optic sensor for determining the presence and/or measuring the depth of a first substance capable of transmitting light. The fiber optic sensor includes a plurality of light receiving fibers, a plurality of light transmitting fibers surrounding the light receiving fibers and structure for refracting light from the light transmitting fibers at a predetermined angle for total internal reflection of the light from an interface of the first substance with a second substance.

Direction Of Arrival Estimation And Tracking Of Narrowband And Wideband Signals, A. Satish, Rangasami L. Kashyap

Department of Electrical and Computer Engineering Technical Reports

The research addresses estimation and tracking of direction of arrival @OA) and associated parameters of narrowband and wideband signals impinging on a uniform linear array of sensors. The signals are modeled as sample functions of a Gaussian stochastic process. Computationally efficient, approximate maximum likelihood (ML) methods are developed for direction of arrival estimation of narrowband signals impinging on a large array of sensors. A new likelihood function is formulated based on a large M (# sensors) Taylor's series approximation of the original likelihood function. Asymptotic expressions for Cramer-Rao lower bounds on the DOA estimates are derived. From the positive definiteness …

Detecting Stator And Rotor Winding Faults In Three-Phase Induction Machines, Jeffrey C. Robertson, Chee Mun Ong

Department of Electrical and Computer Engineering Technical Reports

The purpose of this work is to investigate the efficiency of existing methods for on-line fault detection when applied to three-phase induction motors, spc:cifically to test known theoretical calculations of harmonics developed by certain types of faults experimentally. The work involves the development of equipment and test procedures needed and research of existing methods of fault detection. The experiments are cor~ductedb y planting a fault in a test induction machine and then performing a Fast Fourier Transform (FFT) on the line current. The processed data are then compared with those from the same test machine before the fault was planted. …

Optimal Sequence Estimation For Convolutionally Coded Signals With Binary Digital Modulation In Isi Channels, Fuqin Xiong

Electrical and Computer Engineering Faculty Publications

Decoding convolutional codes with binary digital modulation in intersymbol interference (ISI) channels is studied. The receiver structure is a whitened matched filter (WMF) whose transfer function is determined by the ISI channel. Decoding of the output sequence can be performed in two steps or one step. The two-step decoding first decodes the ISI corrupted coded sequence back to the ISI free coded sequence which is then decoded back to the uncoded message sequence. For one-step decoding, the entire encoder-channel-receiver system is modeled as a new encoder with combined memory length of the memory lengths of the original …

Video Technologies For Roadway Surveillance And Automated Detection, C. Arthur Maccarley, Leonard Ponce

Electrical Engineering

Closed circuit television (CCTV) systems deployed on roadway networks are believed to be among the best mechanisms for providing useful, reliable information for effective traffic management. Video images may be displayed and viewed directly by traffic management personnel for surveillance purposes, or may be processed electronically for detection of traffic metrics such as average vehicle speed, flow volume, and traffic density.

This paper summarizes the current state-of-the art in video imaging and video signal processing technology for traffic surveillance and electronic detection. Technical considerations relevant to the selection of video cameras and computer vision hardware and software for this application …

Inp Optical Constants Between 0.75 And 5.0 Ev Determined By Variable-Angle Spectroscopic Ellipsometry, C. M. Herzinger, Paul G. Snyder, B. Johs, John A. Woollam

Department of Electrical and Computer Engineering: Faculty Publications

Using variable-angle spectroscopic ellipsometry (VASE) InP optical constants for photon energies have been determined in the range from 0.75 to 5.0 eV, which includes the fundamental gap at 1.35 eV. Above 1.5 eV the results are consistent with previously measured pseudovalues from an oxide-stripped sample when a very thin residual over-layer is accounted for. They are also shown to be compatible with previously published prism measurements of refractive index below the band gap. Real and imaginary parts of the dielectric function are shown to be Kramers-Kronig (KK) self-consistent above the gap, and the KK analysis was used to extend the …

On Adaptive Code Division Multiple Access Detectors, Wenping Chen

Dissertations

Several variations of adaptive CDMA synchronous receiver schemes which can automatically adjust to the system parameters, are studied in this dissertation. Unlike their non-adaptive counterparts, these adaptive detectors require no knowledge of the received signals' energies and have similar or better performance.

Minimum energy and decorrelating criterion are used to update the weights. Since weights are updated according to the changes of the detector's outputs, hence no training sequence is required. The convergences of some of the aforementioned adaptive detectors are also disscussed.

The detectors proposed in this dissertation are near-far resistant,thus rendering the high-precision power control unnecessary. Among them, …

Scheduling Of Flexible Manufacturing Systems With Automated Guided Vehicles Using Petri Net Models, Hua-Sheng Chiu

Theses

In this thesis, Petri net models for Flexible Manufacturing Systems (EMS) are constructed. A firing sequence of the Petri net from the initial marking to the final marking can be seen as a schedule of the modeled FMS. By using the branch-and-bound algorithm, an optimal schedule of the FMS can be obtained.

Automated Guided Vehicle Systems (AGVS) are increasingly used for material handling in factories and warehouses. An AGVS can reduce labor costs and is ready to be integrated into an automated factory. This thesis presents two AGVS models (shared and duty) which integrate the control of AGVS with the …

Soft Decision Adaptive Multiuser Cdma Detector For Asynchronous Awgn Channels, Frank Viehofer

Theses

A multiuser detector in an asynchronous, additive white Gaussian noise, codedivision multipleaccess (CDMA) channel is proposed and analyzed. It employs a combination of a decorrelator and a nonlinear multiuser interference canceler that utilizes soft tentative decisions. The weights of the canceler are adaptively adjusted, in a manner that renders the knowledge of received signal energies and the use of training sequences unnecessary. The steady state error performance of the detector is obtained and found to be superior to the performance of the same detector that utilizes hard tentative decisions.

The Mobile Satellite Service (Mss) Systems For Global Personal Communications, Kiho Lee

Theses

A worldwide interest has arisen on personal communications via satellite systems. The recently proposed mobile satellite service(MSS) systems are categorized four areas: geostationary earth orbit(GEO) systems, medium earth orbit(MEO) systems, low earth orbit(LEO) systems, and highly elliptical orbit(HEO) systems. Most of the systems in each category are introduced and explained including some technical details. The communication links and orbital constellations of some systems are analyzed and compared with different categories, and with different systems. Some economical aspects of the systems are mentioned. The regulatory issues about frequency spectrum allocation, and the current technical trends in these systems are summarized.

Performance Evaluation And Sequence Control Of An Automatedmanufacturing System, Vijaykumar D. Desai

Theses

In an automated sequential manufacturing system Programmable Logic Controllers (PLC) are widely used. As the control specification varies, the control software needs to be rewritten to accommodate the new specification. Since PLC has high flexibility, one can update the current system while it is running thereby making easier implementation. In order to design flexible, reusable and maintainable control software, a good modeling tool is required. Petri nets are such a tool. Which facilitates analysis of behavioral properties, performance evaluation, and systematic construction of discrete event simulators and controllers. In this thesis a system with one robot and five sequential work …

Heart Rate Variability Studies On Ambulatory Subjects Using Ekg Derived Respiration, Xiaorui Tang

Theses

Power spectral analysis of heart rate variability (HRV) provides a powerful non-invasive too] for exploring the balance between sympathetic and parasympathetic components of the autonomic nervous system. In the spectrum of HRV, there are three distinct peaks. The high frequency (HF) band (0.15 to 0.4 Hz) is correlated with parasympathetic activity and this is the band of interest 'in the study.

Two OTOUPS Of SL113jeCtS were considered in this work, stroke survivors and subjects performing an oral presentation in front of an audience. Data were collected with a Holter monitor to allow for ambulatory recording. Respiration was derived from the …

Single-Axis Agonistic Motion Control System With Electro-Magnetic Actuators, Alexander Rokhvarg

Theses

A novel single-axis motion control system using solenoid electromagnet actuators is built and successfully controlled using a non-linear real-time control algorithm. Procedures for defining and modeling the electromagnetic actuator are established and implemented. Discrete-time nonlinear control law with global asymptotic stability and zero steady-state error is designed and numerically optimized. Stable operation with small-signal 0dB crossover frequency of 370 Rad/sec and positioning RMS steady-state error of better than 4 micron is achieved. Time domain parameters are verified on a working prototype. A step reference response positioning a 0.35 Kg mass payload over 1 cm travel in under 30 milliseconds is …

Simulation Of Activity Rhythms In The Hamster, Paul Qassis

Theses

In this research, an effort was made to better understand light-dark cycles which influence the physiological and psychological rhythms, circadian rhythms and their behavior. The research concentrated on mathematically modeling circadian rhythms (specifically hamsters' circadian activity rhythms) and establishing a physical correlation and creating a meaningful relationship between the mathematical model's parameters and the real biological oscillators which are responsible for these rhythms. The internal nature of the circadian rhythms is unclear. There is insufficient information and empirical data that describe them. Indirect means have to be employed for the description and exploration of such rhythms. Extensive real data analysis …