Engineering Commons^™

The Magnetotransport Analysis Of Hemt Structures At Low Fields, Naghmeh Nouri

Theses

On the basis of a study on numerous HEMT structures, a simple and useful technique was established for the characterization of 2DEG layers. This technique utilizes the magnetic field-dependence of the resistivity and Hall coefficient of the HEMT structure, to determine the values of the sheet density and mobility of 2DEG in the presence of other parallel conductive layers. This method of analysis was compared with previously used techniques such as Shubnikov-de Haas and the etch removal of the parallel conductive layers. Through this comparison and several measurements it was found that this procedure gives reproducible values for the 2DEG …

Adaptive Fir Digital Filter Design And Simulation In The Noise Reduction System, Jack Jiabing Pang

Theses

The adaptive FIR digital filter is designed to suppress the noise in the tape recording and audio communication systems. The cutoff frequency of the digital FIR filters can be varied adaptively depending on the energy level of the input signal. In audio communication, especially, in tape recording systems, the noise obviously gets much bigger, when the frequency band of the system increases. The noise reduction system makes use of a phenomenon called masking, where the big signal-to-noise ratio makes human ears not sensitive to the noise. In a constant interval time, the system detects the signal level and compares the …

Sputter Deposition And Characterization Of High Tc Superconducting Thin Films, Vipulkumar Patel

Theses

Preparation of thin superconducting films by direct RF sputter deposition on Si, MgO, SrTiO₃ and quartz substrates and silver and Sl3N4 buffer layers (deposited on silicon substrates) was studied. To study resistance versus temperature characteristics of thin films and bulk materials, a computerized measurement system was developed. 1-1.5 pm thick YBaCuO films deposited on Si₃N₄/Si were found to be insulating with room temperature resistance higher than 236KΩ, while films with Ag as a buffer and/or a passivating layer exhibited metallic behavior with room temperature resistances lower than 700mΩ. The area directly under the 2.25 inches …

Simulation And Design Of Field Emission Diode, Yun Yuan

Theses

A new generation of microelectronic devices utilizing vacuum field emission cathodes becomes surging interest in recent years. This paper concentrates on the study of the field emission diode — a basic vacuum microelectronic device. The field emission efficiency, current spatial distribution and time dispersion of conical tips and wedges of various geometrical shapes are compared and calculated by analytical methods and computer simulations. Two field emitter heating effects, namely the Joule heating and Nottingham effect, are discussed theoretically. All the simulation results in this paper are performed on 386 based personal computer. The limiting memory space of PC induced simulation …

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 …

Performance Analysis Of A Dynamic Reservation Multichannel Local Area Network, Abubakar A. Ibrahim

Theses

A reservation multiaccess protocol. is proposed to be used on multichannel local area networks. This protocol is advantageous for networks supporting integrated services. The delay and throughput performance for message transmission are obtained by analysist The delay performance of the protocol is similar to the M-CSMA/CD/IC multichannel network proposed by Marsan and Roffinella. It is found that the reservation protocol can provide better throughput-delay characteristics when the fraction of the total available bandwidth allocated to data is increased. It is also observed that the maximum throughput increases with the increase in the number of channels when the total bandwidth is …

The Design Of Decentralized Optimal Regulator Systems Using Matrix Minimum Principle, Sunny Lai Yick

Theses

This research considers the design of linear, time-varying regulator systems using Matrix Minimum Principle in the frame work of decentralized control theory. The regulator system is modeled in terms of state equation with multiple controllers. Each controller works cooperatively to optimize a common quadratic performance index. An additional constraint is imposed such that the controllers are linear time-varying functions of the outputs.

Necessary and sufficient conditions for optimality of the system are provided by the Matrix Minimum Principle and Hamilton-Jacobi Theory.

Two examples are developed to illustrate the concept.

A Model Of Dc Glow Discharges With Abnormal Cathode Fall, Karl H. Schoenbach, Hao Chen, G. Schaefer

Bioelectrics Publications

A model for an abnormal glow discharge, including a self‐consistent analysis of the cathode fall, was developed. It combines microscopic particle simulation by means of Monte Carlo methods with a fluid model of the gas discharge. The model allows calculations of the steady‐state electrical field distribution, the charged‐particle densities, and the current densities along the axis of the discharge. The model was used to simulate a glow discharge in 80% He and 20% SF₆ at a pressure of 8 Torr with a current density of 1 A/cm². The computed discharge voltage agrees well with measured values. The …

Instrument Matrix Of The Four-Detector Photopolarimeter: Physical Meaning Of Its Rows And Columns And Constraints On Its Elements, R. M.A. Azzam

Electrical Engineering Faculty Publications

The four-detector photopolarimeter (FDP) is an arrangement of four photodetectors for measuring the state of polarization of light. The output current vector I of the FDP is related to the input Stokes vector S by I = AS, where A is the instrument matrix. The rows of A can be viewed as projection operators that determine the output currents of the detectors. This leads to the recognition of four special totally polarized input states, each of which maximizes the output of one detector. The associated four orthogonal states produce minimum signals. Because each detector is absorptive and its output is …

Electrical Properties Of Hydrogenated Diamond, Sacharia Albin, Linwood Watkins

Electrical & Computer Engineering Faculty Publications

Hydrogen passivation of deep traps in diamond is demonstrated. Current‐voltage (I‐V) characteristics of polycrystalline thin film and bulk diamond were studied before and after hydrogenation. On hydrogenation, all the samples showed several orders of magnitude increase in conductivity. Hydrogenation was carried out under controlled conditions to study the changes in the I‐V characteristics of the samples. The concentration of uncompensated traps was varied systematically by hydrogenation. The concentration of electrically active hydrogen was determined from the I‐V data. It is shown that hydrogenation is an alternative to deep‐level transient spectroscopy, suitable for …

Contours Of Constant Pseudo-Brewster Angle In The Complex Є Plane And An Analytical Method For The Determination Of Optical Constants, R. M.A. Azzam, Ericson E. Ugbo

Electrical Engineering Faculty Publications

The locus of all points in the complex plane of the dielectric function є[є_r + jє_i = |є| exp(jθ)], that represent all possible interfaces characterized by the same pseudo-Brewster angle θ_pB of minimum p reflectance, is derived in the polar form: |є| = l cos(ζ/3), where l = 2(tan²Φ_pB)k, ζ = arccos(- cosθ cos²Φ_pB/k³), and k = (1 - 2/3 sin²Φ_pB)½. Families of iso-Φ_pB contours for (I) 0° ≤ Φ_pB ≤ …

Propagation Of Millimeter Wave Signals In Forests Using The Equation Of Radiative Transfer With Strong Forward Scattering Phase Functions, Nack Yang Cho

Dissertations

A forest is a highly scattering medium at millimeter wave frequencies. The propagation of cw millimeter wave signals in forests has been studied previously, both theoretically and experimentally. Published experimental data verified that continuous wave transmission is possible over lengths of the order of a few hundred meters and that a forest acts to strongly scatter energy in the forward direction. The cw studies yielded the determination of the range dependence, beam broadening effects and depolarization effects of millimeter wave signals in a forest. However, pulse broadening effects, which are of importance particularly in the case of digital signal transmission, …

Accurate Calibration Of The Four-Detector Photopolarimeter With Imperfect Polarizing Optical Elements, R. M.A. Azzam, Ali G. Lopez

Electrical Engineering Faculty Publications

The first three columns of the instrument matrix A of the four-detector photopolarimeter (FDP) are determined by Fourier analysis of the output current vector I(P) as a function of the azimuth angle P of the incident linearly polarized light. Therefore 12 of the 16 elements of A are measured free of the imperfections of the (absent) quarter-wave retarder (QWR). The effect of angular beam deviation by the polarizer is compensated for by taking the average, (1/2) [I(P) + I(P + 180°)], of the FDP output at 180°-apart, optically equivalent, angular positions of the polarizer. The remaining fourth column of A …

The Electrical Characteristics Of Semi-Insulating Gallium Arsenide A Material For High Power Switches, David Clifton Stoudt

Electrical & Computer Engineering Theses & Dissertations

An experimental study of the electrical characteristics of semi-insulating gallium arsenide has been performed. The goal of this research was to aid in the development of an electron-beam controlled high-power semiconductor switch. The electrical characteristics were found to be heavily dependent on the deep level configuration of the material being investigated. Two methods of deep level characterization are discussed and their results are compared to the information given by the material manufacturer. Studies were conducted to determine both the steady-state and transient dark current characteristics of the switch. Along with being a function of the applied voltage and the deep …

Manufacturing Workstation Model Using Petri Nets, Reni Alexander

Theses

Petri nets have become a powerful tool for modeling and analyzing asynchronous concurrent systems. In this thesis I apply Petri nets for analyzing and modeling a flexible manufacturing workstation (FMS). A manufacturing workstation is modeled by using Colored- Timed Petri nets, with the consideration of tool handling, raw materials, quality checking and the reuse of reworkable scraps. A simulation program for a simplified Petri net model of manufacturing workstation is described and the production throughput is computed.

Adaptive Transform Coding Of Video With Motion Compensation And Vector Quantization, Jung-Hui Chien

Theses

This thesis proposes an efficient transform coding scheme for the low bit rate video sequence. The redundancy within adjacent video frame is exploited by motion compensated interframe prediction using the efficient independent orthogonal search technique, and the motion compensated frame difference (MCFD) signal is transform coding by 1-D DCT, 1-D HDCT and 2-D DCT, the coefficients are zonal masked, and vector quantizatied adaptively. The encoded MCFD as well as the motion information and variance grouping (side informations) are transmitted to the receiver to reconstruct the frame. The transform MCFD signal is classified into the four groups according to the coefficient …

Reliability Prediction Of Vulcanized Fibre Using Electrical Noise As A Screening Parameter, George A. Donos

Theses

The main objective of this thesis was to find a correlation between the electrical noise generated within the body of Vulcanized Fibre in insulating service and the time of its breakdown under a synergy of electrical, thermal and mechanical stresses. Failure was defined as a material discontinuity, puncture, under accelerated life test conditions. Radio frequency measurements of the partial discharges occuring in the voids of the material were performed on 1240 samples of vulcanized fibre with 10 mil thickness. The level of electrical noise measured was used to classify the specimens into the three following categories: (a) Low Noise:0-2.8μV (0-9db), …

Robotic Arms With Flexible Links As The Links Approach Rigidity, George A. Downes

Theses

The dynamics of single link flexible robotic arms are modeled using the Bernoulli-Euler beam equation and Lagrange's equation. The Bernoulli-Euler beam equation derivation is reviewed and is studied in the limiting case as the flexiblity approaches zero. Using the Bernoulli-Euler beam equation, a procedure is developed to calculate the position of the endpoint of a link given the displacement, slope or curvature of any point on the link. Also a procedure is developed to calculate the minimum Young's modulus of elasticity, E, given a specified endpoint displacement tolerance.

A rigid link model based on Lagrange's equation and a flexible link …

Recursive System Identification Using Least Squares Method, Gholamreza Ghorbani Moghadam

Theses

Input and output sampling, in addition to computer simulations, are now an integral part of system identification. In this thesis, the concept of analyzing any time invariant continuous deterministic system will be developed by identifying a linear discrete - time system equivalent to the continuous one. In this method, two computer programs are written in pascal. The first program applies the Recursive Least Squares Method to discrete - time systems in order to estimate the system components. The second program estimates the future output of the system. Four systems have then identified using the programs.

In this process, system identification …

Evaluation Of Sorting Algorithm Performance On Single Instruction Multiple Data Machines, Dong Kuen Yang

Theses

Partitioning an application program into several tasks and executing them via parallel processing is one way to increase computation throughput and performance. But with a uniprocessor system, the performance increase will be minimal. Computer scientists have developed several multiprocessor systems to gain more speed in computation.

There are several computer architectures, such as pipeline machines, array processors and multiprocessor systems. They provide a parallel execution environment to increase the execution speed. But as the system becomes more complex, the communication traffic density between several processors increases more heavily. It has to provide some kind of control algorithm or routing function …

Design And Analysis Of An Intracranial Pressure And Temperature Sensor Telemetry System, Anshumat Parasar

Theses

This thesis presents a signal conditioning and telemetry system for an implantable pressure and temperature transducer. The initial target application is for measuring the epidural intracranial pressure in the range of 25-100 millitorr and temperature over the range 90 — 110° F. The implant, based on custom silicon IC design can be packaged within a volume of 2cm3 and will require surgical procedures for placement and removal. Effort has been made in this thesis to design the transducer, associated signal conditioning and telemetry circuits for useful operation over a wide range of power supply voltage. The implanted device is powered …

Effects Of N>M Clos Networks On Edge Coloring And Matrix Decomposition Algorithms, Ming-Hsing Lin

Theses

Considered in this thesis are n > m Clos networks on edge coloring and matrix decomposition algorithms. This work uses a two-fold approach to examine the effects of n > m Clos networks on edge coloring and matrix decomposition algorithms. First, edge coloring and matching on bipartite multigraphs are applied to routing on Clos networks. It is demonstrated that edge coloring algorithms which find a minimum edge coloring set up the routing for n > m Clos networks with redundancy. The results presented here indicate that the Euler coloring algorithm has applications on n > m Clos networks because it has fast time complexity …

Protocol Processing Delay Analysis On Ethernet By Simulation Of Njit Ethernet, Jagdish Gangrimal Rangwani

Theses

CSMA/CD based Local Area Networks account for about 75% of the installed LAN base today. As these networks are becoming available for high channel bandwidth, it is important to identify the bottlenecks in these networks. As channels are becoming high speed, bottleneck is shifting from channel to protocol processing. This delay depends on a particular implementation of the protocol and not the protocol standard itself.

This Thesis presents the analysis of delay on Ethernet. To achieve realistic results NJIT Ethernet, as it is configured, is modelled and simulated. Traffic on this network is measured and load on each segment is …

Semiconductor Pressure Sensor And Amplifier With Extended Temperature Range, Abhay Mahadeo Joshi

Theses

In this thesis work, a unique raicrosensor was designed for pressure measurements over the temperature range of -80 C to 125 C. The sensor has CMOS circuitry powered by a single voltage supply. It can be used for military and space applications including monitoring the pressure acting on the nose of the space shuttle.

The sensor consists of a thin silicon diaphragm, which is stressed by external pressure. Four resistors in a Wheatstone bridge configuration are diffused into the diaphragm. The temperature drift in the silicon sensors is dominated by the temperature dependence of the piezoresistive coefficients. The resistors are …

A Cad For Edif Pattern Generation, Mohammad Akram Khan

Theses

Generating a set of test vector for a digital circuit is the most critical step in design and test. It is very important to generate test sequence easily and efficiently. The importance is enhanced by the fact that the simulation database is being used to create test programs. A CAD tool ATPG (Automatic Test Pattern Generator) has been developed to specify and satisfy requirements of designers and test engineers. EDIF (Electronic Design Interchange Format) is followed closely. EDIF targets compatability among foundry services and CAD/CAE systems.

Optimization Of Throughput And Stability For Csma/Cd Channel, Liangshyng Jou

Theses

Multiple access technologies plays an important role in designing distributed computer communication system. Here, CSMA/CD has attracted researchers' attentions in the last ten years. In this paper, based on attributions of the slotted, nonpersistent CSMA/CD system, performance of CSMA/CD channel is analyzed. Adaptive Retransmission Technique is adopted to obtain the maximum throughput. Also, equilibrium contours are derived to discuss the stability of the system. And use FET to measure the stability of CSMA/CD channel that FET gives an approximate measure of the average uptime of an unstable channel.

Analytical Determination Of The Complex Dielectric Function Of An Absorbing Medium From Two Angles Of Incidence Of Minimum Parallel Reflectance, R. M.A. Azzam

Electrical Engineering Faculty Publications

The real and imaginary parts of the complex dielectric function (or complex refractive index) of an opaque substrate or a thick film can be determined from two pseudo-Brewster angles measured in two transparent incidence media of different refractive indices. This two-angle method is simple in that it involves no photometric or polarimetric analysis and in that the solution for the optical properties in terms of the measured angles is explicit, analytical, and direct (i.e. noniterative). The two-angle method is demonstrated for an opaque TiN film on a Cleartran ZnS substrate as a specific example. The effect of angle-of-incidence errors on …

Optimal Algorithmic Testing Of Re-Programmable Logic Arrays, Arvind Chopra

Theses

This research delineates a test strategy and detailed sequence of test vectors for a new class of programmable logic devices (PLDs). This new class of devices is based on architectures that contain programmable logic arrays (PLAs) programmed by on chip integrated static RAMs or EEPROMS. The new PLD architecture poses unique testing problems which require 100% nodal test coverage. Previous PLAs/PLDs did not require that 100% of the nodes be tested since their circuits utilized fuse link crosspoints and were not dynamically reprogrammable. Such devices could be tested by a unique personality pattern that combined the application and the test …

Design Of Robotic Lan Controller And Map Interface, Jayesh M. Joshi

Theses

An application specific integrated circuit has been designed for use as a gateway between two local area networks. This silicon chip provides the gateway function to link the NJIT robotics network and the MAP IEEE-standardized network. This IC utilizes the available Motorola MC 68824 Token Bus Controller for the MAP data path. A special IO design compatible with an optical communication link is used to interface into the NJIT RLAN network.

The gateway IC serves as an asynchronous buffer between the 5Mbps MAP link and the 500 bps local optical link. The control protocol provides the master function for polling …

Fault-Tolerant Interconnection Networks For Multiprocessor Systems, Hamed Mohamed Nassar

Dissertations

Interconnection networks represent the backbone of multiprocessor systems. A failure in the network, therefore, could seriously degrade the system performance. For this reason, fault tolerance has been regarded as a major consideration in interconnection network design. This thesis presents two novel techniques to provide fault tolerance capabilities to three major networks: the Baseline network, the Benes network and the Clos network.

First, the Simple Fault Tolerance Technique (SFT) is presented. The SFT technique is in fact the result of merging two widely known interconnection mechanisms: a normal interconnection network and a shared bus. This technique is most suitable for networks …