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Full-Text Articles in Engineering

Estimating 3-D Motion And Structure Parameters Of A Rigid Planar Object By Establishing Landmark Correspondences, Herman Agustiawan Dec 1990

Estimating 3-D Motion And Structure Parameters Of A Rigid Planar Object By Establishing Landmark Correspondences, Herman Agustiawan

Theses

The application of a landmark based approach in recognizing 3-D rigid planar objects[3] along with two different motion and structure estimation algorithm [21][23] have been studied to perform motion and structure estimation tasks of moving objects. The recognition algorithm is based on a sphericity value derived from affine transformation that maps feature points in the object under observation from first to second view in the 2-D image space. The motion and structure estimation algorithm is based on a unique mapping given four or more feature point correspondences.

More than ten experiments have been done including small and large rigid motions. …


Adaptive Stack Filtering By Lms And Perceptron Learning, Yu-Chou Huang Dec 1990

Adaptive Stack Filtering By Lms And Perceptron Learning, Yu-Chou Huang

Theses

Stack filters are a class of sliding?window nonlinear digital filters that possess the weak superposition property(threshold decomposition) and the ordering property known as the stacking property. They have been demonstrated to be robust in suppressing noise. Two methods are introduced in this thesis to adaptively configure a stack filter. One is by employing the Least Mean Square(LMS) algorithm and the other is based on Perceptron learning.

Experimental results are presented to demonstrate the effectiveness of our methods to noise suppression.


A Transistor Delay Model Based On Charge Conservation, Bharatsingh K. Bisen Dec 1990

A Transistor Delay Model Based On Charge Conservation, Bharatsingh K. Bisen

Theses

Delay information of a circuit is often used in the areas of timing verification, timing analysis, race detection and circuit optimization. Given a circuit its delay can be estimated by various simulation techniques. SPICE is one of the simulation techniques, but it is seen that with the increase in the complexity of the circuit the SPICE circuit simulation technique to obtain delay information become cumbersome and computationally too expensive. So as to overcome the above disadvantages of the circuit simulation technique to obtain delay information various timing delay models were developed. However general survey of most of these timing delay …


Wideband Microstrip Antenna Optimization, Amer Muhammad Alsawadi Dec 1990

Wideband Microstrip Antenna Optimization, Amer Muhammad Alsawadi

Theses

An annular ring patch microstrip antenna was investigated numerically from the bandwidth aspect for a satellite link application. The desired portable antenna should occupy the physical volume of a typical briefcase and operate in the 400-500 MHz band. Numerical optimization is carried out using a commercially available computer package (EM, by Sonnet Software Inc.). The parameters optimized include the substrate thickness, feed location along the annular patch antenna and its relative dimensions. The software package was numerically validated for the rectangular patch geometries reported in the open literature. Experimental verification of this work is left to be carried out in …


Design Of A Microengineered Pressure Sensor, Ranjeet Alexis Aug 1990

Design Of A Microengineered Pressure Sensor, Ranjeet Alexis

Theses

A new family of microengineered vacuum ionization gauges of an approximate volume of 200µ3 has been designed. These devices can he fabricated using existing semiconductor processing capabilities. The focus of this thesis is to scale down the current state-of-the-art for ionization sensors to micron dimensions. These gauges can be manufactured economically and potentially will be integrated with more complex structures and circuitry. In these devices an active ionization volume of micron dimensions is used for launching ions in a trajectory towards a collection electrode. Ionization of gas species is accomplished by an electron flux of sufficient energy. Analysis of …


Comparative Analysis Of Single And Double Dwell Acquisition Schemes, Gurinder Singh Ahluwalia Aug 1990

Comparative Analysis Of Single And Double Dwell Acquisition Schemes, Gurinder Singh Ahluwalia

Theses

Single and double dwell pseudonoise (PN) acquisition systems are described, explained and analyzed. These systems are designed to synchronize a locally generated PN signal with a received PN signal of unknown phase in the presence of noise. The mean, variance and an approximate probability distribution function (PDF) of the acquisition time for the single and double dwell PN acquisition schemes is developed. Intuitively, the double dwell acquisition system should be superior to the single dwell system because of the ability to quickly dismiss incorrect cells and further verify probable hits. It is shown analytically that this is in fact true …


Damage Effects To Si-Sio2 Structures Due To Reactive Ion Etching, Moshe D. Bunyan Jun 1990

Damage Effects To Si-Sio2 Structures Due To Reactive Ion Etching, Moshe D. Bunyan

Theses

This thesis presents the damage effects to the Si ? SiO2 structures due to Reactive Ion Etching (RIE). The research was carried out on Si ? SiO2 MOS capacitors which were fabricated using RIE and wet etch (Hydrofluoric acid etch (HFE)) Process. The experiment was carried out using CV technique and Ellipsometry. Various electrical parameters were measured from CV *curves of these MOS capacitors. It was observed that the CV curve obtained for the RIE etched sample showed considerable deviation from that of the control sample. This indicates the presence of excess of interface trap charge density which …


A Stereo Vision Technique Based On The Multi-Positioned Camera Criterion, Jie Bao May 1990

A Stereo Vision Technique Based On The Multi-Positioned Camera Criterion, Jie Bao

Theses

A modified feature based stereo vision [sic] technique is described in this thesis. The technique uses the curve-segments as the feature primitives in the matching process. The local characteristics of the curve-segments are extracted by the, Generalized Hough Transform.

A set of images of a scene, which are taken by a multi-positioned camera satisfying the parallelism criterion, are first filtered by the Laplacian of a Gaussian operator in different widths, i.e. coarse to fine channels. At each channel, the Generalized Hough Transform is applied to the curve-segments in each image. The curve position, the curve-length, the curve centroid, the average …


Performance Evaluation And Comparison Of Ordinary, Adaptive And Exhaustive Service In The Token Ring Network, Darshakkumar J. Patel May 1990

Performance Evaluation And Comparison Of Ordinary, Adaptive And Exhaustive Service In The Token Ring Network, Darshakkumar J. Patel

Theses

In the token ring network different types of services gives different delay characteristics. Results to date have shown that in asymmetric traffic, exhaustive service gives more delay to lightly loaded stations where ordinary service wastes time in circulating the token after each transmission. In general, there is a need for more efficient service, which is compromised between ordinary and exhaustive service.

Ordinary and exhaustive service are analyzed in this thesis, and a new service, adaptive service, is proposed. By using timer and counter, adaptive service dynamically changes token holding time at the station. Different types of delay characteristics are derived …


Design And Analysis Of Movable Boundary Allocation Protocol, Karun Sekhri May 1990

Design And Analysis Of Movable Boundary Allocation Protocol, Karun Sekhri

Theses

The increasing digital communications traffic will require very high speed networks. The use of high communication speed increases the ratio between end to end propagation delay and the packet transmission time. This increase causes rapid performance deterioration and restricts the utilization of the high system bandwidth in broadcast channel based systems. Using several parallel channels in place of a single channel improves this ratio. For a given system bandwidth the total system capacity is increased by bandwidth division and parallel communication. FTDMA protocols have been suggested for the parallel channel network and these protocols are suitable for different loads. In …


Multiprocessor System Design Tutor : Expert System Approach, Rakesh Kamdar May 1990

Multiprocessor System Design Tutor : Expert System Approach, Rakesh Kamdar

Theses

To increase computational bandwidth and system resilience, integration of several microprocessors in a single system becomes necessary. The overall throughput and efficiency of such a system is directly dependent on the hardware and software interconnection supported by the basic microprocessor chip. Sometimes it becomes difficult to put together all the information for design criteria and all the design related formulas.

The approach made here is to continuously update the hardware and software information in the database related to a given microprocessor. This information can be accessed at any time for efficient design solution. Intel 80386 and Motorola 68020 microprocessors are …


A Study Of The Effects Of Weighting Matrices In Power System State Estimation, Yanshi Wang May 1990

A Study Of The Effects Of Weighting Matrices In Power System State Estimation, Yanshi Wang

Theses

The effects of weighting matrices that may be used in the Weighted Least Squares (WLS) method when applied to the problem of Power System State Estimation (PSSE) are studied. These weighting matrices include the one usually used in the literature and the one used in the utility PSSE programs

The performances of these weighting matrices are compared using the Monte Carlo simulation technique.

To test the performances of the weighting matrices, a PSSE program is developed, different performance indices for state comparison are defined, and many cases are studied.

Results show that the weighting matrix usually used in literature, 1/σ², …


Interconnection Of X.25 Networks, Syed Ayaz Qutubuddin Ahmed May 1990

Interconnection Of X.25 Networks, Syed Ayaz Qutubuddin Ahmed

Theses

The purpose of this work was to investigate the performance of two interconnected X.25 networks via CCITT internet protocol X.75. Since internet protocol X.75 follow the same flow approach as X.25, we are allowed to model the acknowledgement queue in such a way that this queue provides a feed back path from destination to the source queue. Thus we are able to model our interconnected network as a closed queueing network with limited number of packets in transit within the network. Mean Value Analysis with Blocking (MVA) algorithm was applied to obtain the performance characteristics as the resources available were …


An Implementation Of Mht Algorithm For Adaptive Transform Coding Of Speech, Peter Battenschlag May 1990

An Implementation Of Mht Algorithm For Adaptive Transform Coding Of Speech, Peter Battenschlag

Theses

The Modified Hermite Transform (MHT), a suboptimum block transform scheme, is implemented on a TMS320C25 signal processing system with the objective of reducing the redundancy in speech signals and transmit a quantized vector representation at bitrates as less as 0.5 bits per sample.

The generation of the Hermite polynomials with a binomial and several first order IIR filter structures is presented focusing on the fact that no muliplications are required which simplifies the MHT algorithm considerably.

An assembler program performs forward and inverse transformation together with a vector quantization using adaptive bitallocation based on short-time statistics for the transform coefficients. …


Token Bus Lan Performance : Modeling And Simulation, Ramesh Kurnool May 1990

Token Bus Lan Performance : Modeling And Simulation, Ramesh Kurnool

Theses

A simulation model based on CSIM, a process oriented simulated language, to analyze the performance of the Token Bus protocol is developed. Performance measures such as throughput, average delay and maximum delay per packet are presented. System performance is analyzed for different loads, number of stations, network lengths, different physical and logical distribution of the stations with packet length as a parameter. Previous studies were based on the delay-throughput analysis with no discussion on the effect of variation of the logical and physical distribution of the stations on the performance of the model which is done in the present thesis. …


Control Of Stress In Silicon Nitride Thin Films, Ajay Krishnan May 1990

Control Of Stress In Silicon Nitride Thin Films, Ajay Krishnan

Theses

Silicon nitride thin films of varying composition and thickness were deposited on silicon substrates by reactive rf diode sputtering of a silicon target using an argon/nitrogen gas mixture. Film stoichiometry could be controlled by varying the partial pressure of nitrogen, the total sputtering gas pressure and the target rf power. Films with refractive index of 2.01, the value for stoichiometric silicon nitride, could be obtained. Film stress was measured by wafer curvature; refractive index and thickness of deposited films were obtained by ellipsometry and interferometry measurements. The etch rate in buffered HF for films with refractive index 2.05 was 29A/min; …


Design Of A Real Time Optical Sensor For Continuous Blood Cell Separation, Girish S. Yerande May 1990

Design Of A Real Time Optical Sensor For Continuous Blood Cell Separation, Girish S. Yerande

Theses

For continuous measurement and display of oxygen saturation and RBC content in blood during cell separation a reflection type optical sensor is designed based on the theoretical model using the photon diffusion theory. The prototype sensor consists of two arrays of light emitting diodes, red and infrared, and photodiodes. The emission wavelength of LEDs are 660 nm and 800 nm. The 800 rim which is in the infrared region is very close to isobestic value for blood. The prototype sensor is mounted on the blood cell separator equipped with an antitwister mechanism. Each LED emits a specific wavelength of light …


An Artificial Neural Network For Redundant Robot Inverse Kinematics Computation, Wibawa Utama May 1990

An Artificial Neural Network For Redundant Robot Inverse Kinematics Computation, Wibawa Utama

Theses

A redundant manipulator can be defined as a manipulator that has more degrees of freedom than necessary to determine the position and orientation of the end effector. Such a manipulator has dexterity, flexibility, and the ability to maneuver in presence of obstacles. One important and necessary step in utilizing a redundant robot is to relate the joint coordinates of the manipulator with the position and orientation of the end-effector. This specification is termed as the direct kinematics problem and can be written as x = f(q)
where x is a vector representing the position and orientation of the end-effector, q …


Eeg Mapping Using The Personal Computer, Zhuan-Zhang Pei May 1990

Eeg Mapping Using The Personal Computer, Zhuan-Zhang Pei

Theses

An approach for brain electrical activity mapping using a personal computer has been investigated to enhance the visibility of the EECs. An automatic procedure from data acquisition to the final mapping has been developed for on-line or off-line data processing, in which a table-look-up technique has been introduced to eliminate redundant processing. The power spectra in different EEC frequency bands for four electrodes are coded into 15 colors and mapped on a color monitor. The data correspondings to the areas between electrodes are interpolated by the surface spline method. The mapping speed and smoothness has been optimized. An experiment has …


Infrared Tv Camera With Ptsi Schottky-Barrier Detectors, Steven J. Blume Jan 1990

Infrared Tv Camera With Ptsi Schottky-Barrier Detectors, Steven J. Blume

Theses

An infrared TV camera was developed for operating various sizes of Schottky-barrier IR-CCD image sensor chips. A digitally programmable frequency synthesizer is used so that the camera has the flexibility of using a 160 x 244 or 320 x 244 image sensor developed at the David Sarnoff Research Center. The outputs of the camera are compatible with an XYZ monitor, a standard TV monitor, and a computer workstation. Operation of the camera was demonstrated with a 160 x 244 image sensor producing an output on a standard TV monitor. Performance of the IR-TV camera system was investigated by evaluating CCD …


Fault Tolerant Benes Networks, Manoj Bhatnagar Jan 1990

Fault Tolerant Benes Networks, Manoj Bhatnagar

Theses

A fairly large number of fault tolerant topologies have been proposed for the multistage interconnection networks in the recent years. However very few of these schemes have focused on the Benes network. This thesis presents two new fault tolerant architectures for the Benes network. The thesis includes algorithms to construct these fault tolerant networks from a Benes network and the reconfiguration procedure in the event of a fault. The hardware characteristics of both the fault tolerant networks have been analyzed and compared.


Uniformity Corrector And Signal Processing For A 160 X 244-Element Ir-Ccd Camera With Ptsi Schottky-Barrier Detectors, Paul D. Blume Jan 1990

Uniformity Corrector And Signal Processing For A 160 X 244-Element Ir-Ccd Camera With Ptsi Schottky-Barrier Detectors, Paul D. Blume

Theses

An off-set-type, one point response uniformity corrector and the associated signal processing circuits was developed to be used for a 160 x 244-element IR-CCD camera with PtSi Schottky-barrier detectors. Image sensors with PtSi Schottky-barrier detectors exhibit two types of noise in the displayed video output, a temporal noise and a spatial fixed pattern noise. The performance of the image sensor, limited by the spatial noise which obscures low contrast detail and limits camera sensitivity, can be improved by a uniformity corrector. The uniformity corrector was constructed to substantially reduce the spatial noise in the output display by digitally subtracting a …