Engineering Commons^™

Performance Analysis Of A Hierarchical, Cache-Coherent, Shared Memory Based, Multi-Processor System, Raman Nayyar

Dissertations and Theses

We have conducted a performance analysis of a large scale multiprocessor system based on shared buses organized in a hierarchical fashion and employing an easy to implement snoopy cache protocol. · This arrangement, named TREEBUS [ 5], presents a logical extension path for multiprocessor systems based on a single shared bus whose scalability is limited by the available system bus bandwidth [26]. The multiple, independent, hierarchical buses overcome the bus bandwidth limitation and the architecture can scale to relatively large sizes. We have developed an easy to use, reasonably accurate and computationally efficient analytic model for analyzing the performance of …

Measurement Techniques For Noise Figure And Gain Of Bipolar Transistors, Wayne Kan Jung

Dissertations and Theses

First, the concepts of reflection coefficients, s-parameters, Smith chart, noise figure, and available power gain will be introduced. This lays out the foundation for the presentation of techniques on measuring noise figure and gain of high speed bipolar junction transistors. Noise sources in a bipolar junction transistor and an equivalent circuit including these noise sources will be presented. The process of determining the noise parameters of a transistor will also be discussed. A Pascal program and several TEKSPICE scripts are developed to calculate the stability, available power gain, and noise figure circles. Finally, these circles are plotted on a Smith …

Numerical Algorithms For Squaring-Up Non-Square Systems Part Ii: General Case, Pradeep Misra

Electrical Engineering Faculty Publications

In this paper, we present numerical algorithms for squaring a non-square system by finding -additional columns in input matrix (for tall systems) and by finding additional rows in output matrix (for wide systems). Several case are considered depending up the requirements on the ra of the input-output interaction matrix.

Study Of Single-Electron Capture From He, Ne And Ar By Low-Energy Ne^Q+ Recoil Ions Using Translational Energy Spectroscopy, Renad Qubaj-Said

Masters Theses

No abstract provided.

Linear Characteristic Spatial Quadrature For Discrete Ordinates Neutral Particle Transport On Arbitrary Triangles, Dennis J. Miller

Theses and Dissertations

A new discrete ordinates spatial quadrature for arbitrary triangular cells is derived and compared to its rectangular cell linear characteristic counterpart. The triangular mesh is more flexible, allowing curved surfaces and off-axis angles to be approximated with many fewer spatial cells. The triangle method is consistently more accurate on example problems tested here. Arbitrary orientation and size of the triangles allow non-patterned meshes to be developed which appears to ameliorate numerical diffusion. The triangle linear characteristic quadrature converges at nearly the same rate as rectangular Linear characteristic on Lathrop's problem. Mesh sensitivity measurements show large variations in triangle vertex locations …

Development Of An Air-To-Air Refueling Automatic Flight Control System Using Quantitative Feedback Theory, Dennis W. Trosen

Theses and Dissertations

Quantitative Feedback Theory and the improved method Quantitative Feedback Theory are enhanced to include the rejection of disturbance at the system output. The enhanced Quantitative Feedback Theory and improved method Quantitative Feedback Theory processes are applied to the design of an automatic flight control system to regulate position of the C-135B fuel receiving aircraft relative to the tanker during air-to-air refueling. A simple feedback control system is developed that will achieve stable position regulation. State-space aircraft models &re generated. An inner loop autopilot is designed to reduce the plant cutoff frequency and provide the system inputs for the Quantitative Feedback …

Photopolarimeter Based On Planar Grating Diffraction, R. M.A. Azzam, K. A. Giardina

Electrical Engineering Faculty Publications

A division-of-amplitude photopolarimeter (DOAP) is described that employs a diffraction grating in the conventional spectrometer orientation with the grating grooves normal to the plane of incidence. Four coplanar diffracted orders are used for polarimetric analysis to determine all four Stokes parameters of incident light simultaneously and virtually instantaneously (with the speed being determined solely by the photodetectors and their associated electronics); a fifth order is used for alignment by autocollimation or by use of a position-sensing quadrant detector. To sensitize the instrument for the +45° and -45° azimuths of incident linearly polarized light and for the handedness of incident circular …

Spectroscopic Ellipsometry Studies Of Hf Treated Si (100) Surfaces, Huade Yao, John A. Woollam, Samual A. Alterovitz

Department of Electrical and Computer Engineering: Faculty Publications

Both ex situ and in situ spectroscopic ellipsometry (SE) measurements have been employed to investigate the effects of HF cleaning on Si surfaces. The hydrogeniterminated (H-terminated) Si surface was modeled as an equivalent dielectric layer, and monitored in real time by SE measurements. The SE analyses indicate that after a 20-s 9:l HF dip without rinse, the Si ( 100) surface was passivated by the hydrogen termination and remained chemically stable. Roughness of the HF-etched bare Si (100) surface was observed, in an ultrahigh vacuum (UHV) chamber, and analyzed by the in situ SE. Evidence for desorption of the H-terminated …

Radome Depolarization Effects On Monopulse Receiver Tracking Performance, Michael A. Temple

Theses and Dissertations

Boresight Error (BSE), defined as the angular deviation between the true position and the apparent position of a target as indicated by a radar, is an important figure of merit for a tracking radar. A significant contributor to system BSE is the protective radome. This research effort employed a GO technique to investigate the effects of a radome on BSE, expanding previous ray- trace receive techniques to include: (1) a uniquely defined/developed mathematical description for each surface within arbitrary multi-layer tapered radomes, (2) an 'ideal' taper function concept for obtaining optimum BSE prediction performance, (3) a generalized technique for calculating …

Phased Array Antenna Analysis Using Hybrid Finite Element Methods, Daniel T. Mcgrath

Theses and Dissertations

This research in computational electromagnetics developed a new method for predicting the near-field mutual coupling effects in phased array antennas, using the finite element method (FEM) in combination with integral equations. Accurate feed modeling is accomplished by enforcing continuity between the FEM solution and an arbitrary number of wave guide models across a ground plane aperture. A periodic integral equation is imposed above the antenna's physical structure in order to enforce the radiation condition and to confine the analysis to an array unit cell. The electric field is expanded in terms of vector finite elements, and Galerkin's method is used …

A Generalized Data Conversion System, Kevan Morgan

Undergraduate Honors Capstone Projects

To assist in the processing of data files collected by the Space Dynamics Laboratory at Utah State University, the software project GENDACS has been completed. GENDACS, acronym for A Generalized Data Conversion System, will contribute to its research program.

Data are collected from various sensory instruments by the Computer Data Acquisition System. The instrument readings are brought in, tagged with the time they were taken, and stored on an optical disk in a compact, binary (non-ASCII) format. GENDACS is designed so that the program can read in such files, sort out the data, and convert them into a new ASCII …

Feasible Offset And Optimal Offset For Single-Layer Channel Routing, Ronald I. Greenberg, Jau-Der Shih

Computer Science: Faculty Publications and Other Works

The paper provides an efficient method to find all feasible offsets for a given separation in a VLSI channel routing problem in one layer. The prior literature considers this task only for problems with no single-sided nets. When single-sided nets are included, the worst-case solution time increases from Theta(n) to Omega(n^2), where n is the number of nets. But, if the number of columns c is O(n), one can solve the problem in time O(n^{1.5}lg n ), which improves upon a `naive' O(cn) approach. As a corollary of this result, the same time bound suffices to find the optimal offset …

Minimum Redundancy Array Structure For Interference Cancellation, Wan-Ling Chen

Dissertations

Adaptive antenna arrays are widely used in many advanced radar, sonar, and communication systems because of their effectiveness in cancelling intentional or unintentional interferers. A uniformly spaced linear array, referred to as a Uniform Regular Array (URA), is the usual structure used for interference cancellation. The Minimum Redundancy Array (MRA) structure proposed in this work is a special kind of thinned array whose application was limited in the past to direction finding. MRAs with the same number of array elements can resolve directions of much more closely spaced signals than URAs.

The URA structure is customarily utilized for interference cancellation, …

Characterization Of Advanced Etching Reactors Using Novel Diagnostic Tools, Vipulkumar Patel

Dissertations

Plasma etching equipment used for sub-micron integrated circuit fabrication at present are exclusively based on 13.56 MHz, capacitively coupled, parallel-plate geometry. The underlying mechanisms of plasma processes in these reactors are not well understood and there is even less understanding of how the etch-tool parameters relate to the plasma discharge characteristics which actually determine the etch process. In this thesis, new diagnostic techniques were applied for the characterization and optimization of plasma etching processes in various reactor configurations.

Specifically, diode and triode configurations were studied extensively using tuned scanning Langmuir probes. Both radial and axial distributions of plasma density were …

Fair And Efficient Transmission Over Gbps Dual Ring Networks, Abdelnaser M. Adas

Theses

The advances in fiber optics technology provide large bandwidth and enable the support of a wide variety of services. New network architectures have been proposed, such as Metaring and Distributed Queue Dual Bus (DQDB), that try to take advantage of the new capabilities. Because of the very small packet transmission time relative to the feedback time a challenging issue in high speed networks is the efficient and fair share of the channel bandwidth among the competing users. In this thesis we first investigate and compare the performance of the Global and Local Fairness Mechanisms (GFM and LFM, respectively). They have …

Performance Of Different Strategies For Error Detection And Correction In Arithmetic Encoding, George F. Elmasry

Theses

Lossless source encoding is occasionally used in some data compression applications. One of these encoding schemes is the arithmetic encoding.

When data is to be transmitted via communication channel, noise and impurities imposed by the channel cause errors. To reduce the effect of errors, channel encoder is added prior to transmission through the channel. Channel encoder inserts some bits that help channel decoder at the receiver end to detect and correct errors. These added error detection and correction bits are redundancy that causes reduction in the compression ratio and hence an increase in data rate through the channel. The higher …

Design Of A 320x122 Mwir-Ccd Ptsi-Si Imaging Radiometer With Automatic Optical Integration Time Control, Nathaniel Joseph Mccaffrey

Theses

An infrared CCD camera system was designed and developed to operate a 320X244 Schottky-barrier IR-CCD Focal Plane Array (FPA) as an imaging radiometer. The goal of this research was to develop a reliable radiometer capable of resolving temperatures between 50 and 1000°C to within 1°C accuracy using non-contact spectral thermographic methods. To accomodate this wide dynamic range, the imager was operated in a non-interlaced format with variable optical integration times ranging from 120µsec to 122msec. Variable integration control was achieved by employing a "dump and read" timing procedure. To facilitate this operation, novel circuitry was developed for dynamically controlling the …

Aluminum Epitaxy On Silicon, Samuel Cruz Ramac

Theses

The purpose of this work was to study the effect of 4° miscut and chem¬ical pretreatment of Si(111) wafers on the epitaxial growth of Al by thermal evaporation in a UHV environment (~ 10^-9 Torr). Two chemical pretreatments of the wafers were used. One included HF only and the other included NH₄F after an initial HF treatment. The substrates were not heated dur¬ing deposition. XRD measurements of the films were done before and after annealing in a high vacuum oven for one hour at temperatures between 200 and 350°C.

The A1(200) films deposited on wafers pretreated with …

Multilevel Embeddings For Massively-Parallel Hypercubes, Devenkuma P. Shah

Theses

Hierarchically structured arrays of processors have widely been used in the low and intermediate phases of image processing and computer vision. Since the pyramid structure efficiently supports local and global operations extensively required by these phases, it has been widely used for relevant algorithms. Multilevel systems keep all the advantages of the pyramid structure while providing a general hierarchical structure that is easier to be used for the development of several algorithms and may also provide higher performance.

Although the cost of pyramid machines may be tremendously high, they have limited applications. In contrast, the hypercube network is widely used …

Adaptive Two-Stage Detection Scheme In Synchronous Two-User Cdma Systems, Yong Jiang

Theses

A conventional single user detector is not optimum in the multiuser environment because the multiuser interference can not be modeled as an additive Gaussian process. Such a receiver is very vulnerable to the near far situation. The receiver that is optimum for multiuser environment has high complexity and requires a knowledge of the received signal energies. Various versions of the receiver that handle the near far situation have been proposed in the literature. In this work, an adaptive two stage scheme for a synchronous two user environment with unknown received energies is proposed. It consists of a, tandem of the …

Tantalum Silicide Variable Capacitance Rotary Micromotors : Design And Fabrication, Michael Steven Berry

Theses

Tantalum silicide was studied as an alternative microelectromechanical material by fabricating a rotary micromotor utilizing a proven design. This material was used for the rotor, stators, and bearing over a silicon substrate. It has the attraction of potentially reducing the friction which is a major problem with polysilicon-to-polysilicon bearings.

The necessity of high aspect ratio features required that a plasma or reactive ion etch with a high degree of anisotropy be developed to etch tantalum silicide films in excess of 1.5μm. A sulfur hexafluoride/Freon 115 plasma provided the necessary process control during the etches. The stress present in annealed tantalum …

Modeling And Simulation Of Magnetic Micromotor Performance, Ping Wang

Theses

The objective of this research was to model the performance and optimize geometries for two types of magnetic micromotors: yoke-type (YTMM) and yokeless (YSMM). The two selected micromotor types matched the designs that have been described in the recent research literature. Modeling was accomplished using MAXWELL, an advanced 2-D and 3-D simulator. The micromotors with nickel and nickel-iron magnetic thin films for the rotor and stator were simulated for torque performance. Three-phase power supplies with overlapping and non-overlapping phases were used. Rotor diameter dimensions were varied from 285 to 600µm, and the rotor-stator air gap was varied from 3 to …

Modeling And Analysis Of Semiconductor Manufacturing Processes Using Petri Nets, Xinyao Wang

Theses

This thesis addresses the issues in modeling and analysis of multichip module (MCM) manufacturing processes using Petri nets. Building such graphical and mathematical models is a crucial step to understand MCM technologies and to enhance their application scope.

In this thesis, the application of Petri nets is presented with top-down and bottom-up approaches. The theory of Petri nets is summarized with its basic notations and properties at first. After that, the capability of calculating and analyzing Petri nets with deterministic timing information is extended to meet the requirements of the MCM models. Then, using top-down refining and system decomposition, MCM …

Modeling And Investigation Of Current Transport Phenomena In Schottky Structures, Yan Zeng

Theses

We have used a numerical method to describe the importance of the contribution of generation-recombination current to the I-V characteristics of Schottky barrier contacts. The current-voltage relationship is derived directly from the fundamental set of equations such as Poisson; current-density and continuity equations, without having to make many simplifications or approximations. The final result includes not only the thermionic emission or drift diffusion mechanisms of current flow, but also the generation recombination processes.

The experimental devices used for this work are very common low barrier height Schottky structures, Al/T_0.3W_0.7/n-Si/A1 and Ti_0.3W_0.7/n-Si/Al. The …

Microengineered Mass Spectrometer With Field Emission Ionization Source, Chao Sun

Theses

This thesis describes a design for a microengineered mass spectrometer. This mass spectrometer device uses VLSI processing techniques to scale down the dimensions of an existing mass spectrometer and make it portable. It can be manufactured economically and has the potential to be integrated with more complex structures and including transistor integrated circuits. An optimized device is proposed. This device is to be fabricated using two silicon substrates approximately 1cm by 1cm, where one is a cathode electron source and the other is the ion collector. External ion sources are not needed. Electrons are emitted from the array of cathode …

Properties And Determination Of Optimal Decentralized Feedback Structure, Kangsong Han

Theses

In this thesis, the decentralized feedback structure for large scale, linear time invariant systems is studied. The internal differences and the relationship between decentralized feedback structure and centralized feedback structure are discussed. The conventional diagonal feedback structure. corresponding to the classical single loop design strategy, is first analyzed. This is followed by an arbitrary decentralized information flow constraint which is dependent upon the actual plant characteristics. Although signal flow graphs have limited use in describing decentralized control systems. the concept of a control cycle unit based on signal flow is introduced as a supplementary tool to characterize some fixed modes …

Improving The Jitter Performance Of Timing Recovery By Employing Delay Shifts, Xin De Lu

Theses

Many methods have been developed for evaluating the jitter performance of timing recovery circuits for binary synchronous transmission systems. These circuits consist of a nonlinear device followed by a narrowband filter tuned to the pulse repetition frequency. This thesis introduce delay shifts in the timing recovery circuits to improve the jitter performance. The function of the delay shifts is analyzed and mathematical proof of jitter performance improvement is given for the system using square-law device. Finally, the numerical results obtained from the specific examples serve to illustrate the significant improvement between the system with and without delay shifts. That is, …

Polarimetric Fiber Optic Sensor For The Measurement Of Strain, Wei Ma

Theses

In this thesis, development of a Polarimetric Fiber-Optic strain sensor is presented. The sensor uses the phenomenon that strain can deform the probing part of the fiber and hence change the polarization of the transmitted light signal. By counting the resulting fringes, we can measure the exact strain in the material. Calibration of the sensor was achieved by setting up tension tests. Optical fibers were glued on the surface of the specimen. Reference strain gages were used to record the strain in the specimens. Resulting fringes from the fiber optic sensors were then related to the strain measured by the …

An Implementation Of A Versatile Camera Calibration Technique For High-Accuracy 3d Machine Vision Metrology Using Off-The-Shelf Tv Camera And Lenses, Bolang Li

Theses

This thesis studies and implements a new versatile camera calibration technique for high-accuracy 3D machine vision metrology using off-the-shelf TV camera and lenses developed by Roger Tsai [1]. This technique builds up a unique relationship from the world coordinate system to the computer image coordinate system of calibration points by using a radial alignment constraint. The technique has advantage in terms of accuracy, speed, and versatility over existing techniques.

The fundamental knowledge for using this technique is presented in this thesis first, followed by an overview of the existing calibration techniques, and a detailed description of the new technique. The …

The Postbus Fault Tolerant Clos Network, Udayabhanu Sarangapani

Theses

The trend in modern computing is to develop multiprocessor systems with hundreds, even thousands, of processors and memory modules. The task of providing communication paths among all these units is not a trivial one. For a small number of functional units, direct connections could be used but for large systems interconnection networks have to be used. Multistage Interconnection Networks (MINs), provide a dynamic means for interconnecting processors and memory in a multiprocessor system. These networks are built with switches in each stage.

The Clos network is a well defined family of MINs and consists of three stages. The ordinary Clos …