Engineering Commons^™

Convex Bayes Decision Theory, Wynn C. Stirling, Darryl Morrell

Faculty Publications

The basic concepts of Levi's epistemic utility theory and credal convexity are presented. Epistemic utility, in addition to penalizing error as is done with traditional Bayesian decision methodology, permits a unit of informational value to be distributed among the hypotheses of a decision problem. Convex Bayes decision theory retains the conditioning structure of probability-based inference, but addresses many of the objections to Bayesian inference through relaxation of the requirement for numerically definite probabilities. The result is a decision methodology that stresses avoiding errors and seeks decisions that are likely to be highly informative as well as true. By relaxing the …

N-Cross Coupled Phase Locked Loops, Joseph C. Aboukhalil

Theses

Interference cancelation has been mainly performed using arrays, in an important issue in communication both array and spatial cancelation and time domain approach were used. In array applications, depth of cancelation may dependent on the interferences to background power ratio and their spatial distributions. Also, array cancelers are inadequate when the signals are less than an array beamwidth apart. The latter was dealt with using supperesolution and eigenanalysis methods. Different time domain methods were used in the past. Among them what is termed Cross-Coupled PEL. It is an arrangement of two PLL each one is locked on and tracking one …

Fault Tolerant Clos Network, Preet Mohan S. Ahluwalia

Theses

Multistage interconnection networks, or MINs, provide paths between functional modules in multiprocessor systems. The MINs are usually segmented into several stages. Each stage connects inputs to appropriate links of the next stage so that the cumulative effect of all the stages satisfies input-output connection requirements.

This thesis deals with a fault tolerant Clos network. The fault tolerance technique involves addition of extra switches per stage to compensate for any switch failure The reliability analysis of both ordinary and fault tolerant Clos networks is presented. The optimal number of extra switches required to get the best reliability results has been analyzed.

Ct Fan Beam Reconstruction With A Non-Stationary Axis-Of-Rotation, Joseph A. Concepcion

Theses

One important aspect for reconstructing an image using Computed Tomography (CT) is that the axis-of-rotation must pivot at the same point on the reconstruction plane as the x-ray source and CT scanner assembly rotates around the imaged object. This pivot point is used as a reference point for backprojecting pixel values to their proper coordinates. Therefore, reconstructing an image with a non-stationary axis-of-rotation would backproject pixel values to wrong coordinate points, since the reference point is non-stationary for every projection angle.

A convolution filtered backprojection algorithm has been derived for correcting images that were acquired with a non-stationary axis-of-rotation using …

Tri-Color Led Display System Using Microcontroller, Costakis A. Constantinou

Theses

A seven-by-forty-eight tricolor LED display panel is designed and built around the 68HC11 MCU.

Four bilateral switching transistors (4066) are used in a Wien bridge configuration to drive each tri-color LED. With this circuitry one is able to drive the tricolor LED symmetrically. An alternative design that uses only two switching transistors is also offered.

A software program was developed to output on the display scrolling and fixed messages. Each message could be displayed in a different color (Red, Green and Yellow) and at a different speed (Slow, Fast, and Medium). The program also includes an editor with insertion and …

Comparative Study Of Prediction Gain Based On Neural Network Architecture, Prashant M. Shah

Theses

This thesis describes the Neural Network approach to design predictor using Delta and Generalized Delta Rule. The predictor is designed by supervised training based on the typical sequence of pixel values. Neural Network is used to find the coefficients of the predictor. Both 1-D and 2-D scheme of the pixels as well as linear and non-linear correlations are used to find the coefficients by training. Different combinations of pixels are used to find the "best" combination among the order of the predictor.

Novel Way Of Sub-Carrier Coherent Detection And Clock Recovery In Fiber-Optic Communications, Narayan Gehlot

Theses

We experimentally demonstrate a novel concept for recovery of a Sub-Carrier and Timing Clock in fiber-optic communication systems using a Wavelength Division Multiplexing technique. The idea is to send a low radio frequency (RF) as a reference pilot from the transmitter to the receiver on a separate laser using the principle of Wavelength Division Multiplexing (WDM). This low frequency signal is taken to be a subharmonic of the subcarrier used to carry information and intensity modulate another laser. Such approach will be expected to generate at the receiver a local oscillator in high coherence with the subcarrier.

We show that …

Direct Schottky Injection Image Sensors, Subramanyam V. Ayyagari

Theses

This thesis describes the analysis and simulations of Direct Schottky Injection (DSI) imagers which have 100% fill factor. Frame transfer (FT) and interline transfer (IT) DSI imager structures have been investigated. Theoretical Poisson solution for the PT and P-NP FT-DSI structures is presented, which closely agrees with simulation results. Simulation for frame transfer FT-DSI imagers has been done in SUPREM III since 1-D effects are more dominant. Single carrier transit time for both the structures were estimated from the electric fields.

Simulations of IT-DSI structures was done using PISCES llb, to get the local electric fields, which define the directionality …

Multiresolution Techniques : Laplacian Pyramid Coding And Its Comparison With Subband Coding, Danmei Chang

Theses

The multiresolution pyramid and related structures have been developed as intermediate representations between the purely frequency domain and purely spatial domain. In this thesis. we discuss two important pyramid structures which are often used in multiresolution representation: Laplacian pyramid and subband coding.

Laplacian pyramid. a typical pyramid structure, is studied in detail. By means of software implementation. we obtain a comprehensive understanding of its features and applications in image representation and data compression. Several modifications of pyramid structure are used to compress the data dynamic range, reduce the computational complexity and improve performance. Performance of the conventional Laplacian pyramid and …

Fast Packet Switching For B-Isdn With Neural Net Control, Ajit K. Chaudhuri

Theses

The concept of integrated network where both the voice packet and data packet are delt with, started taking shape since 1970. Later, Users? demand for communication of data, voice, file, facsimile, image, videotext, videophone, videomovie has also been felt. All these services need bit rate of transmission in the order of 10, even 100 Mbits. An economical way to transmit this higher bit rate, with flexibility of bandwidth, is to treat voice/video in the form of packets and transmit those packets in real time. Studies of this kind of communication is carried out in Broadband ISDN ( BISDN). At this …

A Machine Vision System With Remote Host, Chieyeon Jason Chen

Theses

The modem plays an important role in data communication using the Public Swiched Telephone Network. In this thesis, the modem function is merged into a low cost machine vision system based on the Motorola 68HC11. Evalation Board The system comprises the intelligent machine vision con- troller and a remotely located host computer, such as an IBM-PC. It, supports extra long distance communication capability so that the controller and the host can be anywhere in the world where then is a telephone line. Because of the limit of a 2100 bps modem, soft ware data compression is implemented here to save …

Artificial Dielectric Polymeric Optical Waveguides, Peng Chen

Theses

Wave propagation in artificial dielectric polymeric optical thin film waveguides is studied. These artificial dielectric films are made of multiple layers either metallic or semiconductor clusters in polymeric matrix. The waveguides are fabricated using the plasma polymerization and vacuumm evaporation deposition method. By analyzing results of these kinds of structures, some important conclusions can be obtained. The artificial dielectric layer in the waveguide center effectively changes the modal distribution in the waveguides. In the case of semiconductor layer, an all optical switch may be realized.

A Multimode Index Detecting Sensor For Use In Plastic Concrete, Qiyu Chen

Theses

This thesis describes a microcomputer-based measuring system using a laser diode source, a fiber optic sensor and a microcomputer DMA interface to test and analyze the entrained percentage of air in concrete.

The principle of refraction and reflection of light in optical fibers is applied to detection of air bubbles. Reflected light intensity signals are detected and transferred through a DMA interface to a laptop computer. Analysis of reflected light intensity produces a measurement of the air content of fresh concrete. Accuracy of the system is evaluated through extensive laboratory and field trials.

Dual Token Ring Lan Performance, Pratap S. Pasupuleti

Theses

A simulation model to analyze the performance of a dual token ring LAN is developed. The performance measures throughput, average packet delay and maximum delay per packet are obtained. System performance is analyzed for different loads, number of stations, and packet lengths. The performances of token ring LANs with a conventional structure and a dual ring structure are compared for both uniform packet sizes and a case with mixed packet sizes. In the uniform packet size case, the dual ring delays were lower at equivalent throughput because of propagation delay effects. In the mixed packet size case the maximum delays …

Design, Fabrication, And Testing Of Temperature Compensated Magfet, Dilip K. Sampath

Theses

A simple model based on dc behaviour of MOS transistors operating in weak inversion is derived on the basis of previous publications. The bipolar like source to drain transfer characteristics of MOS transistor in weak inversion was used to implement a voltage source that is proportional to absolute temperature (PTAT); a cell that can be stacked to obtain the desired voltage. A CMOS temperature compensated current reference is implemented using PTAT cell with MOSFET as current defining element. A CMOS magnetic field sensor has been developed. The sensitivity of sensor is dependant on the bias current; incorporation of temperature independent …

An Efficient Annealing Algorithm For Global Optimization In Boltzmann Machines, Rajendra Sarasakrishna

Theses

This thesis proposes a new annealing algorithm for Boltzmann Machines. This algorithm uses an Exponential Formula for temperature scheduling that produces remarkably better solutions for global optimization. The superiority of the new algorithm is shown by computer simulations of several examples on Boltzmann Machine and its variants. This is also shown to have better properties than algorithms like Generalized Simulated Annealing which possess somewhat similar dynamics.

Efficient Multiprocessor Scheduling By Mean Field Theory Neural Networks, Pei-Ken Yi

Theses

In this thesis, we develop an optimization method based on Mean Field Theory (MFT) Neural Networks to solve the Task Scheduling problem. The MFT algorithm combines characteristics of the Simulated Annealing (SA) algorithm and the Hopfield neural network. MFT exhibits rapid convergence and at the same time it preserves the solution quality afforded by SA. Since MFT has been successfully used to solve the Traveling Salesman Problem (TSP), a new modification to MFT is also presented which supports Task Scheduling problem. The temperature behavior of MFT during Task Scheduling is approximately analyzed and shown to possess a critical temperature (71,) …

Uniformity Correction For Infrared Ir-Ccd Camera, Chien-Ming Leng

Theses

This thesis describes the results of a study of three types of uniformity correction schemes for an infrared camera. More specifically, a Datacube Image System was used to simulate the three uniformity correction schemes for a 320x244-element IR-CCD TV camera with PtSi Schottky-barrier detectors. The three uniformity correction schemes are: one-point uniformity correction with single background, one-point uniformity correction with multibackground and two-point uniformity correction. Datacube programs were developed for the three above uniformity correction schemes and some experimental results were obtained.

On The Estimation Of New Life Model Of Transformer Insulation Material Under Combined Electrical And Thermal Stress, Chiming Lin

Theses

Results of combined electrical and thermal aging and only thermal aging studies conducted on a 'fish' paper insulation material are presented in this thesis.

The model for aging has been proposed which is essentially the Arrhenius equation with a weighted factor {exp -cg/kT1 to describe the enhanced reaction rate process under combined thermal and electrical stress. A procedure has been described for evaluation of parameters of this new model.

It is seen that life estimates obtained with this model are close enough to the experimental results.

In addition, reliability data were also generated on the same material using electrical noise. …

The Bandwidth Allocation Of Atm Through Genetic Algorithm, Hong Pan

Theses

In this thesis, we develop an optimization method based on Genetic Algorithm to achieve the bandwidth allocation of ATM network. In Broadband Integrated Service Digital Network (BISDN), the Asynchronous Transfer Model (ATM) is already adopted as the transfer standard by CCITT. ATM is a high-bandwidth, low-delay, fast-packet switching and multiplexing technique. Using ATM technique, we can flexibly reconfigure the network and reassign the bandwidth to meet the requirement of all types of services. As an effective optimization method, Genetic Algorithm(GA) is applied to implement the bandwidth allocation of ATM. GA is a class of search algorithm based on the mechanics …

Hot : A Timing Optimizer For Hierarchical Vlsi Circuits Using The Charge Conservation Delay Model, Yumei Quan

Theses

The primary benefits of VLSI chips are their high speed, small area, and lower power. These performance attributes are dependent on the quality of chip design. As a result, performance can be optimized by proper design decisions. One of the decisions in chip design is the selection of gate delays and/or transistor sizes (channel width of an MOS transistor).

To optimize the performance of VLSI chips, transistor delay models and optimization algorithms are very important since accurate analytical models for signal delay are essential to replace expensive device level simulation and the high efficient algorithms assist designers in developing high …

Integrated Digital Speech System With Pc, Zhen Zhu

Theses

A PC-based real-time digital speech processing system is designed. Speech synthesis, analysis, storage and retrieval are implemented in the system with intelligent telephone functions. Speech data are stored on floppy disk and easy to retrieve. Though floppy disk is slow in speed, real-time processing is achieved with low bit rate coding. The computer gets speech data from a digital speech processing unit or send data to it through a synchronous seiial communication port. The analog input of digital speech processing unit can be selected from the telephone line or the microphone, and output of the digital speech processing unit can …

Decomposing Non-Product Form Queueing Lattices Through Autorouting With A* Algorithm, Chun-Chang Yu

Theses

Direct solution techniques are expensive for the state transition lattice of a class of non-product form queuing modes. In this thesis, Autorouting with A* algorithm is adapted to decompose it as solvable subsets which can be solved sequentially and independently. Autorouting with A* algorithm is heuristics in problem solving. It also is one of a class of global optimization problems that are difficult to solve. Some queuing modes of type A will be decomposed in this thesis through Autorouting with A* algorithm.

Hybrid Wafer Scale Microcircuit Integration -- [ 4989063 ], Edward S. Kolesar Jr.

AFIT Patents

A wafer scale integration arrangement wherein integrated circuit die of varying size, fabrication processes, and function are commonly mounted in the same host wafer using a filled epoxy material of special characteristics. The mounting epoxy material also serves as a substrate for the die interconnecting conductors in regions adjacent the mounted die. The described assembly also includes a newly available photosensitive polyimide material as a planarization and passivation covering for the die and host wafer and as a mounting surface for an interconnecting metal conductor array. Multiple levels of interconnection metal. Fabrication processes for the die to host wafer attachment …

Forming Fine Particles, Dennis R. Alexander

Department of Electrical and Computer Engineering: Faculty Publications

To alter feedstock material, the material is exposed to laser radiation applied at a selected angle of incidence, intensity and wavelength related to the refractive index of the feedstock material. Fine uniform particles may be formed through vapor explosion and/or plasma formation and used by this method to coat surfaces, such as with paint or adhesive or to suply uniform small particles to a heat engine. Moreover, moving materials such as a column of liquid may be subjected to high internal pressure and temperature for creating physical and chemical changes.

What To Look For And Why When Buying A Telecommunications Switch

ACUTA: Other Publications

There are three characteristics of institutions of higher education that have a strong

impact on telecommunications:

. Campus Environment

. Multiple Service Populations

. Limited Budgets

Each characteristic translates into requirements for an effective telecommunication

system.

To Serve the Campus Environment

A campus is usually the first image associated with the word "college" or "university." Typically, institutions of higher education are housed in several buildings which may be fairly close together, or spread over some distance, perhaps reaching across a city or even a state.

To serve the campus user, a system must provide feature transparency, regardless of location. Small …

Photorefractive Materials For Optical Signal Processing, William B. Lawler

Retrospective Theses and Dissertations

The optical response of the photorefractive crystals KNbO₃:Ta, KNbO₃:Fe, LiNbO₃:Fe, and nominally pure BaTiO₃ is investigated. In the experiment, a holographic grating is built in the crystal under investigation via a two-wave mixing scheme that utilizes the signal-processing capacities of two acousto-optic Bragg cells. The dynamic interaction of the Bragg cells with the photorefractive grating causes a heterodyned RF signal to appear on the output laser beam, enabling the real-time, direct measurement of the amplitude and phase of the space-charge fields in the crystal. Experimental results are presented for the amplitude and phase …

Application Of A Six-State Passive Track Filter Within A Weapon-Delivery System For A Lock-On-After-Launch Missile, Lynda Jeanne Ciaponi

Retrospective Theses and Dissertations

Knowing the benefits that a passive air target tracking system gives the host aircraft attempting to conceal its own presence on the battlefield, it is desired to determine whether the aircraft can also deliver one of its own lock-on-after-launch air-to-air missiles to the target via use of the same passive system. The objective of this thesis is to demonstrate that a passive six-state track filter can be successfully used within such a weapon delivery system. The role of the filter within the system is to track the enemy target in cartesian space utilizing only line-of-sight measurements and to track the …

Texture Segmentation And Classification Using Fractal And Energy Measures, Qing Chen

Retrospective Theses and Dissertations

This thesis introduces a multi-feature based texture segmentation and classifi­ cation algorithm. We first present general background on segmentation approaches which can be categorized into three groups : characteristic thresholding and clus­ tering, edge detection, and region merging. According to our texture segmentation objective, we choose characteristic thresholding and clustering along with region merging as our segmentation method which is accomplished by a popular K-mean algorithm applied in the feature space. Fractal geometry is receiving increasing attention as a model for natural phe­ nomena. We present an efficient method for estimating the fractal dimension of image surfaces and show that …

Rs170 Image Processing Interface, Charlotte Christou

Retrospective Theses and Dissertations

This thesis deals with the hardware design and implementation of an image processing board that digitizes RS-170 video, passes it thru a sobel filter and sends the results to a high-resolution color printer. Most sobels deal with black and white images, but this thesis uses a static color image. The hardware design will allow direct printing from a RGB separate channel RSl 70 video source to a Tektronix 4693DX Color Printer through a Centronics port. It will also allow the red, blue and green video channels to pass through a sobel filter, with the resulting image being sent out to …