Digital Commons Network^™

An Investigation Of Broadband Current Preamplification For Obtaining Simultaneous High-Resolution Energy And Time Information From Nuclear Radiation Detectors, Joe Kenneth Millard

Doctoral Dissertations

In beginning the investigation of low noise current preamplification, noise-performance limitations of existing broadband current-amplifying stages are considered. Dominant noise sources of the general, shuntfeedback amplifier stage having both bipolar and field-effect transistor input devices are discussed. This discussion includes the reasons why optimum noise performance from this amplifier stage requires unavoidable signal integration. The integrating shunt-feedback configuration is commonly known as the charge-sensitive preamplifier. Criteria are developed for differentiating the output voltage pulse of the charge-sensitive preamplifier without degrading the signal-to-noise ratio. Subsequently, a new broadband, shunt-feedback amplifier is described having a current gain equal to the ratio of …

Application Of Positive Feedback Techniques To Charge-Sensitive Preamplifiers, Willaim Pinkston Albritton Jr.

Doctoral Dissertations

The application of positive feedback techniques to charge-sensitive preamplifiers for the purpose of improving their performance characteristics and versatility is considered. Improvements in sensitivity of charge gain in input capacitance, preamplifier output pulse rise-time, and ability to terminate long input cables are discussed. In each case, theoretical developments are carried out in order to determine the optimum positive feedback conditions. A practical charge-sensitive preamplifier design is discussed and the effects of applying positive feedback are delineated.

For the experimental preamplifier, the application of positive feedback resulted in a reduction in charge gain sensitivity to input capacitance changes of almost an …

Reliability Aspects Of Semiconductor Surface Protective Coatings, Robert Edward Mcmillan

Dissertations

This research was directed towards the occurrence and im-portance of surface leakage in reverse biased semiconductor diodes and the relation of this leakage to the reliability of a device under use conditions. As a result of this study, it is possible to predict one important leakage mechanism after such back-biased diode units have been subjected to long periods of temperature and humidity. This theory is consistent with tests of commercially available units, some of which have very slight surface leakage and others very large surface leakage.

Further, the usefulness of various possible passivating coatings is critically analyzed on the basis …

Oscillations In Pulse Frequency Modulated Control Systems, Warren Joseph Guy

Dissertations

This dissertation is concerned with oscillations and their stability which occur in a control system containing two nonlinearities, separated by linear elements. Specifically the nonlinearities are Integral Pulse Frequency Modulators and the linear elements are described by ordinary differential equations which are linear. The IPFM can be modelled by a quantizer with hysteresis and many other PFM laws are related to IPFM, thus the study applies to more than just IPFM alone.

Boundaries on the system parameters are identified within which free oscillation may be possible. These boundaries give sufficient conditions for stability and necessary conditions for instability. Also since …

A Study Of An Unintentional Shutdown (Scram) Problem In The Operation Of The High Flux Isotope Reactor, Cheng Ping Wu

All Graduate Plan B and other Reports, Spring 1920 to Spring 2023

The High Flux Isotope Reactor (HFIR) at the Oak Ridge National Laboratory experiences occasional operating difficulties caused by temporary low voltage conditions on its main power feeder line. The low voltage causes the shutdown of one or more of the three primary coolant pumps. When two of these pumps are shut down, the capacity of the cooling system is reduced to the point where the reactor is scrammed due to a high inlet coolant temperature.

This study was made to determine the cause of the high inlet temperature when operating with one primary coolant pump and to suggest possible changes …

A Study Of The Secant Law For Sporadic E, Ruey-Yuan Han

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The secant law is the relationship between the frequencies of a vertically incident wave and an obliquely incident wave that are reflected from the same level (i.e., density) of a stratified ionosphere. This thesis investigates the validity of the secant law applied to sporadic E.

Sporadic E data from two backscatter sounders and one vertical incidence ionosonde located in Japan were studied to test the validity of the secant law. The B-scan photos of the backscatter sounders were searched for E_s patches which were then compared with the sporadic E parameters defined for vertical incidence ionograms.

Finally, two theoretical …

Systems Reliability Using The Flow Graph, Kenneth Edward Farrier

Dissertations and Theses

The problem of calculating the reliability of a complex system of interacting elements is delineated to a linear system, no element of the system having a reliability distribution in terms of any other e1ement of the system, where only one path is taken through the system at a time. A precise definition is then developed to specify the reliability of the linear, single path at a time, system. A precise and concise generating function is found that effortlessly produces the reliability of the linear, single path at a time, system directly from the reliability flew graph of the system.

Statistical Estimate Of Positional Error Inherent In Very Low Frequency Radio Navigation (Range-Range), Jimmie D. Mcginnis

Masters Theses

"To determine the effectiveness of Very Low Frequency (VLF) navigation in certain areas of the world, it is necessary that a method be developed to estimate the positional error associated with VLF relative positioning techniques. This paper presents a method which consists of a least-mean-squared procedure to sum up the errors contributed by each station being monitored. Since phase jitter (i.e., phase fluctuation) is a random variable, a statistical approach is employed to produce a one Σ ellipse centered about the true position. In short, this method defines the size and orientation of an area called an error ellipse which …

Fault Detection In Asynchronous Sequential Circuits, Jeng-Chuan Kau

Masters Theses

"As the asynchronous sequential circuit has become more and more important to digital systems in recent years high reliability and simple maintenance of the circuit is stressed. This paper presents a fault-detection algorithm which will be applicable to most of the practical asynchronous sequential circuits. The asynchronous sequential circuit is treated from the combinatoric point of view. First the minimal set of states, both stable states and unstable states, sufficient to detect all possible faults of the circuit is found from the fault table. Then a test sequence is generated to go through these states. It is assumed that testing …

On-Line Digital Computer Decoding Of Radio Teletype, Julio Alberto Spiegel

Masters Theses

"Digital computer data processing is one of the newest and fastest growing technologies. The large amount of data that can be processed is practically beyond the limit of human possibilities when available time, cost and reliability of results are taken into consideration. The use of on-line digital computer data processing to decode Radio Teletype is investigated in this thesis. The first part of this thesis considers existing teletype systems and related systems, such as Pulse Code Modulation, pointing out the differences between synchronous and asynchronous codes. The most critical step in decoding Radio Teletype is synchronization, since Radio Teletype makes …

Integrating An Oscilloscope Into A General Purpose Automatic Test System, William Charles Bauer

Masters Theses

"The General Purpose Automatic Test System was developed for the Air Force as a system to automatically test and fault isolate an electronic unit under test. The Test System is a building block concept and this paper developed the hardware and programming software necessary to integrate an oscilloscope into the system. A Tektronix Type 564 oscilloscope with a Tektronix Type 3A5 Programmable Amplifier and a Tektronix Type 3B5 Programmable Time Base was used. A prototype of the digital and analog interface between the Test System and the Tektronix System was built and demonstrated. The Oscilloscope Building Block displays waveforms only …

A Digital Simulation For Optimum Nonlinear Detection Of Binary Signals In Impulsive Noise, Ralph Bernard Fluchel

Masters Theses

"The problem of reducing the effects of impulsive noise on binary communication systems is considered. A digital simulation of such a system is developed in order to find a nearly optimum (minimum probability of error criterion) nonlinear device to precede detection. The level of the Gaussian noise power is found to be the most important parameter for determining the nearly optimum nonlinear device"--Abstract, page ii.

The Effects Of Magnetic Fields Upon The Steady State And Short Circuit Performance Of Low Voltage Multi-Link Fuses, John Thomas Schultz

Masters Theses

"The steady state and short circuit performance of multi-link fuses is investigated, as it is affected by the magnetic field of the nearby returning current and the current flowing in the fuse itself. The fuses investigated are low voltage (600 volts or less), multi-link fuses with ratings between 400 and 4000 amperes. The effects of the above mentioned magnetic fields upon the steady state current distribution within the fuse and upon the mechanical forces acting on the individual fuse links are calculated, while the effects of close proximity of the returning current upon short circuit fuse performance are shown by …

The Evaluation Of Radar Guided Missile Performance Using Various Target Glint Models, Franklin Delano Hockett

Masters Theses

"A radar guided missile seeker approaching a target arrives at a crossover point beyond which the entire target is illuminated by the missile seeker's radar antenna beam. When this occurs, for a complex target, the radar senses a time changing target center location which may greatly complicate the terminal tracking portion of the seeker's flight. This thesis documents various glint models in use today and compares the performance of these models by using a seeker model to determine the effect of glint on terminal tracking performance. A large volume of data has been compiled describing various radar characteristics of complex …

An Analysis Of A Quadrature Double-Sideband/Frequency Modulated Communication System, Denny Ray Townson

Masters Theses

"A QDSB/FM communication system is analyzed with emphasis placed on the QDSB demodulation process and the AGC action in the FM transmitter. The effect of noise in both the pilot and message signals is investigated. The detection gain and mean square error is calculated for the QDSB baseband demodulation process. The mean square error is also evaluated for the QDSB/FM system. The AGC circuit is simulated on a digital computer. Errors introduced into the AGC system are analyzed with emphasis placed on nonlinear gain functions for the voltage controlled amplifier"--Abstract, page ii.

Z-Form Solution Of Non-Linear Differential Equations, Allen Joseph Rushing

Masters Theses

"The "Z-Forms" developed by Boxer and Thaler from Z-Transform theory are reviewed. Iteration is shown to increase accuracy when Z-Forms are used to obtain numerical solutions to some non-linear differential equations. Machine results are presented for example problems. Error estimates and convergence conditions are discussed. The method is usable only when 2- or 3-digit accuracy is acceptable. For some classes of equations the Z-Form method compares favorably to other numerical methods in time required to set up the problem and in machine time required for solution--Abstract, Page ii.

Fault Detection On Sequential Machines, Chung-Tao David Wang

Masters Theses

"This paper presents an algorithm for deriving an optimum test sequence for detecting faults in a synchronous machine. In this study, the flow table is used as a tool to generate the fault detection tests. The fault stuck-at-1 (or stuck-at-0 ) is said to be present when a permanent signal valued 1 (or 0) appears on a component of the machine. Only single faults are treated . The result of the procedure is one or more test sequences guaranteed to detect a set of faults (F_p). First, sequential machines with feedback lines as memory elements are considered . …

An Explicit Simulation Of Overland Flow, Glendon Taylor Stevens

Masters Theses

"Computer simulation of overland flow requires a mathematical model which converges to a true solution. This paper presents a method, based on measurable physical parameters, which insures convergence of a fixed grid explicit numerical solution. Analysis of a wide range of overland flow plane parameters has resulted in an equation of the form Δt = 0. 2 ΔX/S_o, for the time step increment. This equation provides values for Δt that will insure stability and convergence of the fixed grid explicit numerical method of solving the spatially varied unsteady flow equations. The effect of subarea shape on the rising …

Computerized Methods For Estimating Heating-Cooling-Ventilating System Usage In All-Electric Buildings, Carl William Glaser

Masters Theses

"This thesis develops a method and a resulting computer program for estimating the energy input required by the heating-cooling-ventilating system of a building. The computer program has the ability to model the ventilating system and all the inefficiencies introduced when the heating system is allowed to fight the cooling system to provide temperature control within the conditioned space. The program also can consider mechanical heat reclaim accurately, making the consideration on a time of need versus a time of occurrence basis. The program is written to utilize input data in rather simplified form. This allows the program to be used …

Digital Simulation Of A Signal Conditioner/Bit Synchronizer, Quentin Reed Webb

Masters Theses

"A bit rate filter type signal conditioner/bit synchronizer used in a split-phase PCM system is modeled digitally in three stages to determine overall system performance. General computer algorithms are developed to approximate independent operation of each major segment within the device. Bit rate effects and signal time-base error are investigated yielding the characteristic G-curves for the phase detector. These characteristics facilitate subsequent analysis of a linear equivalent digital-data-transition tracking phase-locked loop under several typical time-base error input conditions. Using bit error probabilities as performance criteria, the conditioner/synchronizer is found to perform adequately at signal-to-noise ratios exceeding +10dB. For inputs below …

Digital Simulation Of A Costas Loop Demodulator In Gaussian Noise And Cw Interference, Ajay Mugatlal Mehta

Masters Theses

"A digital computer model of a Costas loop has been employed to study the effects of Gaussian noise and continuous-wave interference on the detection of biphase modulated signals. The dependence of bit-error probability, mean-square error between input and output, phase-error variance and threshold on signal-to-Gaussian-noise power ratio, interference-to-Gaussian-noise power ratio and frequency offset of the interference have been investigated and compared with previously obtained experimental results. The model has been verified for its accuracy in the case of no noise and when Gaussian noise is present at its input"--Abstract, Page ii.

Model-Referenced Adaptive Control Of Plants With Noise And Inaccessible State Vector, Donald James Schooley

Doctoral Dissertations

"The problems of process noise, measurement noise, and inaccessible process state vector in the model-referenced system of Shackcloth-Butchart-Parks (SBP) are investigated. Since the system no longer possesses a static equilibrium point, the concept of asymptotic stability does not apply. However, by using Liapunov-like ideas, the error between the plant (process plus controller) and the model is shown to enter a region about the origin if certain bounds are known. A possible technique for reducing the size of this region is to feedback a function of the error into the plant's input. Several methods of circumventing the inaccessible state vector problem …

Next-State Equation Generation For Asynchronous Sequential Circuits - Normal Mode, Gregory Martin Bednar

Masters Theses

"This paper describes the known methods of generating next-state equations for asynchronous sequential circuits operating in normal fundamental mode. First, the methods that have been previously developed by other authors are explained and correlated in a simple and uniform language in order that the subtle differences of these approaches can be seen. This review is then followed by a development of a new method for generating minimal next-state equations which has some advantages over the previous methods. From the comparison of the previous known methods, it is noted that any one of these methods may be desirable for certain designs …

The Dinary Numerical System And Its Applications To Modern Parallel Processing Computers, Hai Chi Koo

Masters Theses

"The Dinary Numerical System (DNS) is an extension of Binary Numerical System. By utilizing the newly developed Large-Scale-Integration technology, DNS can be implemented as a new concept of computer organization which has the merits of parallel processing. DNS consists of three field elements: they are -1, 0, and +1. Since DNS representation is not necessarily unique, new algorithms to generate the number of representations and all equivalent representations are presented in this paper. A Block-Oriented-Computer (BOC) is developed as an array of computing systems. For each of the systems, the arithmetic unit is essentially a modified Digital Differential Analyzer. The …

Computer-Controlled Processing Of Radar Precipitation Signals And Lightning Data, Gary Wayne Neal

Masters Theses

"A system for the simultaneous processing of radar precipitation signals and lightning stroke location data has been designed. The system is to be used for the purpose of determining spatial and temporal correlations of lightning and thunderstorm precipitation. This system has been developed to gain further information about the cause-effect relationship between lightning stroke activity and thunderstorm precipitation. Data acquisition and processing is accomplished through the use of an AN/FPS-18 radar set, an SCC-650 digital computer system, a radar interface, and a set of lightning detectors. The radar set provides information on precipitation activity in a circle of radius fifty …

An Approximate Min-Max Solution To The Identification Problem, Richard Loyd Warren

Masters Theses

"A technique based on the min-max error criterion is proposed for identifying a dynamic system in terms of a discrete-time model from the system response to a deterministic input. A linear, single-input/single-output, lumped-parameter, time-invariant (at least during the measurement interval) system is assumed. Although the resulting problem is non-linear, it is shown that linear programming techniques are applicable if a realistic approximation is made. The technique is implemented on the digital computer and evaluated by considering a number of typical discrete-time systems. The effects of additive noise are also considered"--Abstract, page ii.

An Analysis Of A Synchronization Scheme For 180° Biphase Modulated Signals, James Joseph Spence

Masters Theses

"The problem of analyzing a synchronization system for demodulation of 180° biphase modulated signals is considered in this thesis. The system considered utilizes the so-called squaring loop technique. Techniques derived from the theory of Markov processes are utilized in the analysis of the system. In particular the "fluctuation equation" approach for non-Markovian processes is used. After the analysis of the system is performed, an expression fro the bit error probability is obtained from knowledge of the phase error density function"--Abstract, Page ii.

Re-Design Of Cloud Chamber Instrumentation, Stanley Forrest Vaninger

Masters Theses

"Instrumentation and a new valving system is designed and built for use with an expansion type cloud chamber. Digital equipment is used for timing to improve reliability, accuracy, and flexibility, and a servo system is built using a lead compensator circuit which improves the servo system typically used with cloud chambers. Special care was taken to eliminate the sources of noise that appear in the amplified signal from the pressure transducer. The equipment needed to measure, record, and calibrate the pressure inside the chamber is built"--Abstract, page ii.

Iddap -- Interactive Computer Assistance For Creative Digital Design, Richard Franklin Crall

Doctoral Dissertations

"A new computer-aided design program to assist in the initial phases of logical design is described. The program, intended for use via an on-line remote terminal, will allow the designer to study and experiment with design alternatives during the initial creative design phases. An ALGOL-like language is used for specifying the system being designed. In addition to simulating the design, the program allows the user to perform on-line design changes, reorganize data and generate timing diagram information"--Abstract, page ii.

Synthesis Heuristics For Large Asynchronous Sequential Circuits, Robert Judson Smith

Doctoral Dissertations

"Many well-known synthesis procedures for asynchronous sequential circuits produce minimal or near-minimal results, but are practical only for very small problems. These algorithms become unwieldy when applied to "large" circuits with, for example, three or more input variables and twenty or more internal states. New heuristic procedures are described which permit the synthesis of very large machines. Although the resulting designs are generally not minimal, the heuristics are able to produce near-minimal solutions orders of magnitude more rapidly than the minimal algorithms. A method for specifying sequential circuit behavior is presented. Input-output sequences define submachines or modules. When properly interconnected, …