Engineering Commons^™

Robotics Development And Design: Optical And Computer Controls, David E. Brown

Opportunities for Undergraduate Research Experience Program (OURE)

In industry today, the use of robotic systems is growing. They can be found in many diverse applications including washing dishes, assembling automobiles and carrying explosives. With such a wide range of applications, robotic systems are a very important division of engineering.

Designing such systems requires an interaction between different disciplines of engineering. In the work world, engineers are required to interrelate with other engineers of differing disciplines and backgrounds. This research was designed to implement this type of partnership and develop a project that required the knowledge of an electrical, a mechanical and a computer science engineer.

Using the …

Microcomputer Control Of A Model Robot System, David N. Ilges

Opportunities for Undergraduate Research Experience Program (OURE)

The project involved creating an interface board that would allow an I.B.M.- AT computer to control a model robotic system already in existence. The I.B.M.- AT computer was then to be programmed in Pascal such that the model robotic system could perform various path movements and functions. The interface board involved taking various digital outputs from the computer and converting them to analog control signals or use them to turn devices off and on. The interface board also would collect inputs from the robotic system and convert these analog values back to digital words.

Development Of Software For Detecting Certain Key Features In Skin Tumor Images, Dana M. Brewer

Opportunities for Undergraduate Research Experience Program (OURE)

The goal of Dermvis is to develop a microprocessor-based system that will economically and clearly identify a skin tumor area and type. Dermvis is subdivided into various segments. This segment includes developing software, digitizing images, and manually defining borders in images. Manually drawing borders for digitized images creates bit-maps for average color analysis. Software is developed for determining the average color of the tumor and the surrounding tissue. Batch processing allows images to be analyzed in mass.

Implementation Of T1545 In Air Pressure Control, Kenneth D. Kangas

Opportunities for Undergraduate Research Experience Program (OURE)

The Texas Instruments Model 545 programmable logic controller is used to control the air pressure in a heating/ventilation simulator designed and built for a classroom experiment station. Through the use of the PLC's built-in PID algorithm, the pressure in the duct was controlled to within a 2% tolerance and over 72% of the sensor range for a load setting of 10%. The theory of PID controllers and their application to this problem are discussed. Also, the configuration of the simulator, and plans for future work are described.

Suppression Of Multiple Pulse Formation In External-Cavity Mode-Locked Semiconductor Lasers Using Intrawaveguide Saturable Absorbers, Dennis J. Derickson, R. J. Helkey, A. Mar, Judy R. Karin, J. E. Bowers, R. L. Thornton

Electrical Engineering

Imperfect antireflection coatings in external-cavity mode-locked semiconductor lasers can cause multiple output pulse generation. The incorporation of an intrawaveguide saturable absorber segment into the laser suppresses this problem. Single pulse outputs of less than 2.8 ps and 0.7 pJ of energy are obtained using such devices with both quantum well and bulk active regions

Comparison Of Synchronization Techniques For The Afit Direct Sequence Spread Spectrum System, Edward A. Bednar

Theses and Dissertations

The purpose of this study is to analyze and evaluate the performance of several code synchronization methods that could be used in the Air Force Institute of Technology's (AFIT) Direct-Sequence Spread Spectrum (DSSS) communication system. These methods include the sliding correlator, transmitted reference, sequential estimation, and three types of matched filters. The matched filters are the baseband matched filter, delay line matched filter, and the convolver. The criteria used for the evaluation of these synchronization methods are theoretical synchronization times and probability of bit-error. Advantages and disadvantages of each synchronization method are described and a method is recommended to be …

On Planar Routing Of Multi-Terminal Nets In Vlsi Physical Design, Jahangir A. Hashmi

Masters Theses

In this thesis, we study two problems related to the physical design of VLSI circuits. One problem is related to the VLSI global routing and the other is related to the detailed routing in a bounded region.

We consider the routing of multiple multi-terminal nets on a single layer. We suggest a new approach for this problem. Our approach is based on simultaneously finding a forest of k non-intersecting spanning trees. We present an O(n^3) algorithm for finding two spanning trees corresponding to two nets on a single layer.

We also study the problem of finding a minimum Steiner tree …

A Study Of Numerical Integration Techniques For Use In The Companion Circult Method Of Transient Circuit Analysis, Charles A. Thompson

Department of Electrical and Computer Engineering Technical Reports

Circuit transient analysis packages such as SPICE and EMTP are very widely used, but detailed information on the internal structure and error characteristics for these software packages is lacking. Both SPICE and EMTP rely on numerical integration to approximate the transient response of circuit elements. The numerical integration methods used in the packages are not necessarily the most accurate approximations to the actual response of a circuit. The study of these numerical integration methods and their error characteristics is the focus of this thesis. Comparisons are made between several methods in terms of accuracy and stability as well as algorithm …

Neural Network Based Vowel Articulation Training Aid For The Deaf, Andrew E. Beck

Electrical & Computer Engineering Theses & Dissertations

Teaching the hearing-impaired to speak is both a challenging and rewarding task. Computer-based training aids are valuable teaching tools and complement the speech therapist in the speech training process. We have developed a computer based vowel articulation training aid designed to provide visual feedback for vowel production to the hearing-impaired user. This system transforms speech spectra from a multi-dimensional acoustic space to a two-dimensional phonetic space which is displayed on a computer monitor. The system signal processing includes feature extraction designed to mimic the properties of the human ear, and a transformation to a two-dimensional display space. The dimensionality transformation …

Formant Estimation From Dctc's Using A Feedforward Neural Network, Shubhangi U. Kelkar

Electrical & Computer Engineering Theses & Dissertations

Formants are the natural frequencies of the human vocal tract. Existing methods for estimating formants from speech signals are computationally complex and subject to errors for certain type of speech sounds. This thesis describes a method for estimating vowel formant frequencies from Discrete Cosine Transform Coefficients (DCTC's), a form of cepstral coefficients, using a feedforward neural network with back-propagation training. Experimental results are based on a large multispeaker data base. The results are obtained for both a linear transformation and a feedforward neural network with a nonlinear hidden layer. In general, the neural network transformation is superior to the linear …

Optimization Of Cryopreservation Protocols For Cardiovascular Tissue, Jianfei Hu

Theses and Dissertations in Biomedical Sciences

The purpose of this research was to determine the effects of cryopreservation on the physical, biochemical and cellular aspects of heart valve tissue. The present study demonstrated that radiolabeled proline accumulation provides a quantitative estimate of total cellular metabolic viability. Radiolabeled inulin was demonstrated to be a useful marker for extracellular tissue space. Assessment of metabolic viability of the cellular population of leaflet tissue as a function of procurement and processing revealed that proline accumulation declined with increasing warm and cold ischemic times. Amphotericin B and streptomycin were toxic to the cells. Cefoxitin, lincomycin, polymyxin B, vancomycin and penicillin had …

Fault Coverage Measurement Technique For Analog Circuits, E. Paul Ratazzi

Electrical Engineering and Computer Science - All Scholarship

This report describes an effort to develop a technique for measuring the amount of fault detection coverage that an analog test pattern has for a particular analog device. The technique is based on a software tool which statistically analyzes data from a circuit simulator. One example of a fault simulation experiment is presented, and some of the results are discussed. Finally, some ideas for future work in this area are given.

Mapping Programs To Parallel Architectures In The Real World, Dezheng Tang

Dissertations and Theses

Mapping an application program to a parallel architecture can be described as a multidimensional optimization problem. To simplify the problem, we divide the overall mapping process into three sequential substeps: partitioning, allocating, and scheduling, with each step using a few details of the program and architecture description. Due to the difficulty in accurately describing the program and architecture and the fact that each substep uses incomplete information, inaccuracy is pervasive in the real-world mapping process. We hypothesize that the inaccuracy and the use of suboptimal, heuristic mapping methods may greatly affect the mapping or submapping performance and lead to a …

Experimental Evaluation Of Incorporating Digital And Analog Integrated Circuit Die On A Common Substrate Utilizing Silicon-Hybrid Wafer-Scale Integration Technology, Philip C. Reamy

Theses and Dissertations

The objective of this research effort was to investigate the implementation of analog circuits in a wafer scale integration system. A test circuit composed of analog and digital subsystems was designed and tested through simulation. IC die containing this test circuit were utilized in the WSI system fabrication. Preliminary investigations were conducted to evaluate the potential improvements to the IC die mounting procedure, a key step in fabricating functional WSI systems. These investigations demonstrated a procedure which produced repeatable results in achieving acceptable planarization of IC die and host substrate surfaces. These investigations also demonstrated the successful application of a …

Transient Overvoltage Testing Of Environmental Controllers, Richard S. Gates, Larry W. Turner, Douglas G. Overhults

Biosystems and Agricultural Engineering Faculty Publications

The integrated electronic control system will provide a new method for the day-to-day management of environmental control of animal production systems. No standards are currently accepted for transient overvoltage protection of these controllers. To assess the adequacy of existing designs, a test circuit was designed and used for a transient open circuit over-voltage waveform (ANSI/IEEE C62.41-1980) of 16 environmental control units: a maximum spike of 770 V was applied to the power supplies, and a spike up to 100 V was applied to temperature sensor lines. For these relatively mild tests, no failures were noted due to power supply transients, …

Developing Cmmca Flight Profiles For Cruise Missile Tracking, Andrew C. Hachman

Theses and Dissertations

The Air Force has recently acquired two aircraft dedicated for cruise missile tracking. These aircraft, known as the Cruise Missile Mission Control Aircraft (CMMCA), are responsible for collecting data from the missile and United States. Due to tracking and positively controlling the missile during live fire testing over the western the limited tracking radar range and the flight characteristics of the CMMCA, tracking cruise missiles through complex maneuvers is not always possible. A FORTRAN optimization, based on flight simulation and optimal control theory, was written in a prior thesis effort in order to determine optimal CMMCA flight profiles for tracking …

A Lower-Bound For The Error-Variance Of Maximum-Likelihood Delay Estimates Of Discontinuous Pulse Waveforms, Kurt Louis Kosbar, Andreas D. Polydoros

Electrical and Computer Engineering Faculty Research & Creative Works

A new lower bound is developed for the error variance of maximum-likelihood time-delay estimation when the received signal is a square pulse, corrupted by additive white Gaussian noise. The bound is generated by combining concepts previously developed for a special class of stochastic processes, induced by the signal model. For moderate signal to noise ratios, the new bound is significantly tighter than previously known ones.

Three-Dimensional Insulated Gate Bipolar Transistor (Igbt) Development, P.V. Gilbert, G.W. Neudeck

Department of Electrical and Computer Engineering Technical Reports

A new insulated gate bipolar transistor structure, the 3D-IGBT, is presented. The 3D-IGBT utilizes selective epitaxial silicon to form a top contacted anode and still retain the cellular structure of vemcally oriented devices. The 3D-IGBT , unlike other fully integrable power devices, exploits the merits of cellular structure to increase its packing density and thus reduce its on-resistance per unit area. It also eliminates the parasitic JFET resistance found in vertical IGBT's. To integrate the 3D-IGBT with low power devices, the QDI method of device isolation is also presented. QDI uses a combination of JI and DI to electrically isolate …

Achieving A Given Reflectance For Unpolarized Light By Controlling The Incidence Angle And The Thickness Of A Transparent Thin Film On An Absorbing Substrate: Application To Energy Equipartition In The Four-Detector Photopolarimeter, R. M.A. Azzam, Kurt A. Giardina

Electrical Engineering Faculty Publications

At a given wavelength λ we determine all possible solution pairs (ϕ, ζ) of the incidence angle ϕ and the thickness ζ of a transparent thin film on an absorbing substrate that achieve a given unpolarized light reflectance R_u. The trajectory of the point that represents a solution pair in the ζ, ϕ plane depends on the optical properties of the film and substrate and on whether R_u is greater than or less than the normal-incidence reflectance -R₀ of the bare substrate. When R_u > - R₀, the specified reflectance is achieved over a …

Hardware-Verification Through Logic Extraction, Michael A. Dukes

Theses and Dissertations

A Prolog-based system is described which employs logic-extraction to perform hardware-verification. The extraction rules are built automatically from hierarchical structural VHDL models, enabling the equivalence of a structural VHDL description and a layout specification to be verified. Pin-to-pin critical- path analysis is performed within the logic-extraction process; many noncritical paths are pruned early, making pin-to-pin critical path analysis of large circuits feasible. It is demonstrated that a design methodology based on logic extraction, VHDL, and a layout tool can provide a fabricated functionally- correct IC design without circuit-level or switch-level simulation. This methodology is shown to be practical for VLSI …

Design And Analysis Of Electrical Circuits That Produce Fractional-Order Differentiation, Richard N. Hughes

Theses and Dissertations

Two half-order differentiator circuit designs were investigated and their electrical performance evaluated (Oldham and Oldfield). Initially, each circuit design was computer modelled and simulated using the HSPICE computer analysis program. Then, each circuit design (Oldham and Oldfield) was fabricated with two different component technologies. This resulted in four circuits, realized on printed circuit boards, to be evaluated--Oldham discrete component; Oldham hybrid component; Oldfield discrete component; and Oldfield surface mount component. The characterizations of each circuit's electrical performance is documented with time, phase, gain, noise and spectrum responses. A comparison of each circuit's performance versus the design criteria and computer model …

Detection, Location, And Quantification Of Structural Damage By Neural-Netprocessed Moire Profilometry, Barry G. Grossman, Frank S. Gonzalez, Joel H. Blatt, Jeffery A. Hooker

Electrical Engineering and Computer Science Faculty Publications

The development of efficient high speed techniques to recognize, locate, and quantify damage is vitally important for successful automated inspection systems such as ones used for the inspection of undersea pipelines. Two critical problems must be solved to achieve these goals: the reduction of nonuseful information present in the video image and automatic recognition and quantification of extent and location of damage. Artificial neural network processed moire profilometry appears to be a promising technique to accomplish this. Real time video moire techniques have been developed which clearly distinguish damaged and undamaged areas on structures, thus reducing the amount of extraneous …

Finding A Maximum-Density Planar Subset Of A Set Of Nets In A Channel, Ronald I. Greenberg, Jau-Der Shih

Computer Science: Faculty Publications and Other Works

We present efficient algorithms to find a maximum-density planar subset of n 2-pin nets in a channel. The simplest approach is to make repeated usage of Supowit's dynamic programming algorithm for finding a maximum-size planar subset, which leads to O(n^3) time to find a maximum-density planar subset. But we also provide an algorithm whose running time is dependent on other problem parameters and is often more efficient. A simple bound on the running time of this algorithm is O(nlgn+n(t+1)w), where t is the number of two-sided nets, and w is the number of nets in the output. Though the worst-case …

Improved I/O Pad Positions Assignment Algorithm For Sea-Of-Gates Placement, Shyang-Kuen Her

Dissertations and Theses

A new heuristic method to improve the I/O pad assignment for the sea-of-gates placement algorithm "PROUD" is proposed. In PROUD, the preplaced I/O pads are used as the boundary conditions in solving sparse linear equations to obtain the optimal module placement. Due to the total wire length determined by the module positions is the strong function of the preplaced I/O pad positions, the optimization of the I/O pad circular order and their assignment to the physical locations on the chip are attempted in the thesis. The proposed I/O pad assignment program is used as a predecessor of PROUD. The results …

An Intelligent Database For Psubot, An Autonomous Wheelchair, Dieudonne Mayi

Dissertations and Theses

In the design of autonomous mobile robots, databases have been used mainly to store information on the environment in which the device is to operate. For most of the models and ready systems, the database when used, is not a stand alone component in the system, rather it is only intended to keep static information on the disposition and properties of objects on the map.

In this thesis is implemented an intelligent database. It combines static facts to build more information. An intelligent database such as this one will be a plus for an intended autonomous machine such as the …

Model-Based Target Recognition Using Laser Radar Imagery, Robert Y. Li

Department of Electrical and Computer Engineering: Faculty Publications

Autonomous target recognition can be assisted by using CO2 laser radar data. Of these data, range data provide 3-D geometric information and Doppler data boundaries of moving targets. A powerful 3-D feature extraction algorithm based on the Hough transform is used to obtain the orientations and dimensions of the target. This information is then utilized by an inference procedure that recognizes targets based on the available evidence from the sensory data. The experimental results using actual laser radar imagery are successful and the procedure can be used for the future development of a model-based system for target recognition.

Transient Stability Test Systems For Direct Stability Methods, V. Vittal, D Martin, R Chu, J Fish, J C. Giri, C K. Tang, F. Eugenio Villaseca, R G. Farmer

Electrical and Computer Engineering Faculty Publications

A standard set of power system data with benchmark results are presented against which direct stability techniques to assess transient stability can be compared and tested. The test systems have been selected to display a wide range of dynamic characteristics to provide a robust test of the efficacy and accuracy of the various analytical techniques to analyze transient stability. Transient stability test system data and benchmark results obtained from two commercially available time-domain stability analysis packages are presented

Analysis Of Algorithms For Velocity Estimation From Discrete Position Versus Time Data, Ronald H. Brown, Susan C. Schneider Phd, Michael G. Mulligan

Electrical and Computer Engineering Faculty Research and Publications

Algorithms for constructing velocity approximations from discrete position versus time data are investigated. The study is limited to algorithms suitable to provide velocity information in discrete-time feedback control systems such as microprocessor-based systems with a discrete position encoder. Velocity estimators based on lines per period, reciprocal-time, Taylor series expansion, backward difference expansions, and least-square curve fits are presented. Based on computer simulations, comparisons of relative accuracies of the different algorithms are made. The least-squares velocity estimators filtered the effect of imperfect measurements best, whereas the Taylor series expansions and backward difference equation estimators respond better to velocity transients.

Series Compensation Investigation On The Hydro-Quebec And Nypa 765 Kv Transmission System : Modeling And Stability Analysis, Hans J. Candia

Theses

This thesis presents a mathematical approach for raising the power steady state stability limit by adding series capacitive compensation to a transmission line. The effect of series capacitive compensation and degree of compensation were investigated in detail. The power system studied includes an automatically controlled power system, IEEE Type I.

The results of the actual and theoretical steady state stability limits for a given series capacitance location and degree of compensation were obtained by applying the frequency domain technique. The natural frequencies of each compensated power network were examined.

The best location for series capacitive compensation is proposed which is …

Ion Exchanged Glass Waveguides With Efficient Coupling To Fibers And Lasers, Shiqing Hu

Theses

To be of practical use in optical communications networks, optical components must have both low on-chip losses and efficient coupling to fibers, semiconductor lasers and detectors. In this thesis work two types of channel waveguides were designed and fabricated on BK7 glass substrate using a low-cost ion-exchange process. The first type of waveguide was formed in a simple sequence of ion-exchange and post-exchange annealing. These single mode waveguides had large mode size and were efficiently coupled to single mode fibers. The lowest loss achieved in fiber-guide direct coupling was 1.25 dB. The second type of waveguide was formed in a …