Electrical and Electronics Commons^™

Methods Of Achieving High Speed On Data Flow Machines, Chung-Lin Yu

Theses

Simultaneity is a key to high speed and large computation. Assuming hardware components of a given speed, it is the only remaining consideration in achieving raw speed. Simultaneity can be shackled by dependencies, however, and years of hardware and software work have been devoted to understanding the types of dependencies and how they can be obeyed or removed from a computation.

In this thesis, the principles of the data flow machines and the structure of the data flow languages are illustrated. Various methods of achieving high speed are discussed. These methods include streams, Lenient Cons (I-structure), and dependence-driven computation, which …

Integrated Voice/Data Services On Multihop Radio Networks, Chialun Lu

Theses

Integrated voice/data is the first step toward Integrated Services Digital Networks (ISDN). Various techniques have been proposed and analyzed for multiplexing voice and data over a large bandwidth channel. Network efficiency is what we are most concerned about. In this paper, we address the problem of determining optimal access policies for a tandem ISDN network by using Dynamic Programming. Computer simulation shows that optimal policy minimizes the data delay.

Statistical Multiplexing Of Video Sources For Packet Switching Networks, Krishna Kancherla

Theses

Communication networks are fast evolving towards truly integrated networks handling all types of traffic. They employ integrated switching technologies for voice. video and data. Statistical or asynchronous time division multiplexing of full motion video sources is an initial step towards packetized video networks. The main goal is to utilize the common communication channel efficiently, without loosing quality at the receiver. This work discusses the concept of using statistical multiplexing for packet video communications. The topology of a single internal packet network to support ISDN services has been adopted. Simulations have been carried out to demonstrate the statistical smoothing effect of …

Rays And Beams Near The Shadow Boundary, Weixing Gao

Theses

Asymptotic techniques in wave propagation problems exhibit attractive features in computational aspects compared to numerical methods. However, they experience problems in complicated environments due to the transition regions associated with them. The transition region involving a shadow boundary in the downward refractive index profile has been investigated. The ray paths were determined solving the ray equation analytically. The Green's function due to a line source is constructed and evaluated using numerical integration (reference solution) and asymptotic techniques. Then, the field produced by the source, is synthesized, using superposition of beams generated from complex source point representation. The floating parameters such …

Maximum Rate Of Change Of The Differential Reflection Phase Shift With Respect To The Angle Of Incidence For Light Reflection At The Surface Of An Absorbing Medium, R. M.A. Azzam, A. M. El-Saba

Electrical Engineering Faculty Publications

The differential reflection phase shift, Δ = δ_p - δ_s, associated with the external reflection of monochromatic light at the surface of an absorbing medium is a monotonically decreasing function of the angle of incidence ø which is determined by the complex dielectric function ε. A new special angle of incidence, denoted by ø_Δ′max, is defined at which the slope Δ′ = ∂Δ/∂ø of the Δ-ø curve is maximum negative, Δ′_max, and a transcendental equation is derived that determines this angle. ø_Δ′max differs from the principal angle ø_p at which Δ …

A Wideband Continuous Phase Shifter For Ka-Band, William J. Tanis

Theses

The design, fabrication and test of a 45 degree microstrip phase shifter capable of full Ka-band performance is presented. The design uses a Lange coupler with two ports terminated with beam-lead varactor diodes to provide continuous phase shift. Although this concept has been employed at X-band and below, this thesis demonstrates its feasibility for wideband use at frequencies as high as 40 GHz. The design uses thin-film capacitors, beam-lead diodes, simulated grounds, and air bridges to achieve a planar geometry and to simplify the production process. Detailed test results using various test circuits are shown for comparison to actual phase …

Design Of A Lan Based Data Acquisition System For Sensor Applications, Krishna Murthy Uppunda

Theses

This thesis presents the design of a local area network (LAN) based data acquisition system for sensor applications. The circuit designed forms the robotic LAN (RLAN) interface between the sensor IC nodes and the ARCNET network. The RLAN network uses two packet protocols. The sensor data request (SDR) packet is received by the sensor IC nodes and the sensor transmits the sensor data (SD) packet. The RLAN interface provides a two way communication between the sensors and the ARCNET network. Whenever an ARCNET node receives the SDR packet, it stores the packet temporarily in a 1k RAM buffer. The RLAN …

X.25 Interface Packet Level Simulation, Arvind Tewari

Theses

An X.25 interface was simulated at the packet level and data packets successfully transmitted from the Data Circuit-Terminating Equipment (a process) to the Data Terminal Equipment (another process). This was executed interactively. Two independent processesg were generated on the AT&T 3B15 computer and inter-process communication (IPC) used to transfer the data. The X.25 interface is based on the Open System Interconnection (OSI) model of the International Standards Organization.

A Microcomputer Based Non-Invasive Cardiopulmonary Monitor Using A Microwave Interferometer, Tanmoy K. Basu

Theses

With a microwave interferometer the vibrational velocity of the anterior (front), as well as posterior (back) chest wall can be monitored and recorded. The recorded signals are a reflection of the mechanical cardiac activity within the chest cavity, as opposed to Electrocardiogram (ECG) which is a reflection of the electrical cardiac activity. The interferometer recordings are obtained with no physical contact between the instrument and the subject. Moreover, the subject can be fully clothed since microwave energy readily passes through normal dry clothing.

A microwave interferometer that is capable of detecting the vibrational velocity of the surfaces of the chest …

Design Of A Temperature Sensor For Gallium Arsenide Ic Applications, Raviprakash Raviprakash Gutala

Theses

This thesis presents the design of a temperature sensor circuit including sensor, differential amplifier, and a memory element for gallium arsenide IC standard cell applications. A standard 1-um depletion-mode GaAs MESFET technology has been used for the design of the circuit. The circuit is intended to be used as a standard cell in GaAs les providing an alarm when the sensor temperature reaches 125 °C. The circuit includes a NAND latch which is set when the chip cell temperature reaches 125 °C. The output of the latch can be sensed by additional circuits (on or off the GaAs chip) which …

Microprocessor-Based Processing Unit Implemented By Xilinx Programmable Logic Array, Lee Chuan Hu

Theses

The 8052 microprocessor-based processing unit is a super single board computer with many unusual features: memory page selecting with page indicators, on-board EPROM/PROM programmer, real time clock, battery back-up RAM, and memory mapped I/O. It is implemented by using Xilinx programmable logic array and can be used for various instruments. Xilinx user-programmable Application-Specific Integrated Circuit (ASIC) is a large logic array with up to 9000 equivalent gates. The advantages of programmable logic devices over standard ICs are more flexibility, design security, lower cost, higher performance, reduced power consumption, smaller size, and increased reliability. The system development time is also greatly …

Reliability Problems And Failure Mechanisms In Ic Packaging, Dilip J. Patel

Theses

Today, reliability is acknowledged as an important item in design and operation of electronics circuits and system.

This thesis provides information on evaluation of the reliability for hermetic and non hermetic IC packages made by different manufacturers.

Literature study concentrates on the reliability and related problems in IC packages developed between 1970 and 1988.

Several failure mechanisms and failure modes are discussed to point out how higher reliability in IC packages may be achieved.

The bibliography is given in a chronological order to help further research in this area.

Generation Of Atomic Nitrogen By Gas Discharge In Microwave Cavity, Jong-Shun Shieh

Theses

A microwave discharge system for producing atomic nitrogen at low flow rate and low pressure has been investigated. The molecular nitrogen passes through a microwave cavity in a quartz tube and is dissociated by the microwave energy. Subsequent recombination of nitrogen atoms produces a characteristic yellow glow due to the relaxation of excited molecular nitrogen to its ground state. The titration of nitric oxide with atomic nitrogen was used to measure the atomic nitrogen yield. At a 2 sccm nitrogen flow rate the atomic nitrogen yield was 8.75*10¹⁵ atom/sec, which corresponds to a nitrogen generation efficiency of about 1%. …

A Cmos Digital Temperature Sensor For Asic Vlsi Standard Cell Design, Chih-Ta Sung

Theses

This thesis describes the design of a CMOS digital temperature sensor cell including the physical layout database.This cell is designed for implementation within an ASIC VLSI chip as a standard cell . The digital temperature sensor can trigger an alarm signal and turn off power for preventing fatal damage in the VLSI chip if overheating occurs.A digital output also permits measurement of temperature over the 0 - 120°C range with ±3.4°C accuracy using standard VLSI foundry processing. Two sensing elements are implemented in a differential mode within the temperature sensor cell. An operational amplifier is used in the successive approximation …

A Methodology For Designing Spacecraft Onboard Processing Systems, Mohammad Nadeem Ahmad

Theses

A three layer methodology is presented for designing spacecraft onboard computer systems. The system design is perceived as a sequence of three hierarchical layers: the Dedicated Processing Layer, the Application and Support Processing Layer, and the Communications Processing Layer. Each layer implements a distinct set of functions and offers services at different levels of abstraction. As opposed to the ISO/OSI Reference Model, where the prime objective is to implement peripheral interaction between two systems, the layered approach used here is to address the problems in system design itself. The problem is approached in a bottom-up fashion, starting with the description …

Progressive Transmission Of Images Using Pyramidal Structure, Chin-Hua Hsu

Theses

A progressive image transmission scheme based upon Laplacian pyramid structure is used for image coding over low-bandwidth channels. The filtering and differential pulse code modulation (DPCM) methods of image coding are generalized to allow quantization of the Laplacian images. Filtering is performed with a local, symmetric weighting function. The three different quantizers, (1) scalar quantizer, (2) memoryless vector quantizer (VQ), and (3) finite state vector quantizer (FSVQ), are used here to compare the results. In the receiver end, the image can be reconstructed using reverse procedure. The reconstructed image is not the same as the original image because of the …

Use Of The Lms Algorithm In Ecg Analysis, Xiaohua Yang

Theses

The purpose of this thesis is to develop an IBM PC-AT based system to effectively process electrocardiogram (ECG) signals. Adaptive filter theory is used to implement a noise cancellation system (adaptive noise canceller), which adaptively cancels the ECG signals resulting in real ECG noise. The adaptive process is based on the well known least-mean square (LMS) algorithm.

The noise canceling system is software based. Several programs have been written, which include analog to digital converter control, data acquisition and storage, data retrieval, adaptive filtering and digitized data graphics.

The thesis presents numerous computer experiments. The performance of the adaptive noise …

Computer-Controlled Programmable Pulse Generator For A Jeol Jnm-Ft-1a Radio Frequency Amplifier Section Of A Nuclear Magnetic Resonance Spectrometer, William H. Russell, Roger M. Hawk

Journal of the Arkansas Academy of Science

A microprocessor controlled programmable pulse generator was specifically designed to interface with the JEOL JNM-FT-1 A Radio Frequency (RF) section of a nuclear magnetic resonance (NMR) spectrometer. The programmable pulse generator was programmed and controlled by an IBM compatible computer. Statis rams were utilized as the programmable pulse generator's on board memory which were used to store the pulse sequences. Pulse widths can be programmed from 0.2 microseconds to 14.3 minutes. The JEOL RF section is unique in that it allows the pulse generator to control the phase of the RF transmitted to the NMR probe and whether the sample …