Power Metal Oxide Semiconductor Field-Effect Transistors (MOSFETs) are widely used in power supplies for spaceborne electronic systems. Spacecraft are routinely subjected to ionizing radiation. Ionizing-radiation-induced charges alter the operation of the MOSFET. The mid-gap technique allows separation of the parameter shifts into components due to oxide trapped charge and interface trapped charge. However, non-linearity in the subthreshold curve results in an approximately 20% underestimation of the interface component of the threshold shift. A new characterization technique is presented based on the relation between gate charge and gate-source voltage. The results obtained using the gate-charge method agree with theoretical calculations.

A finite-element formulation for the analysis of shielded lossy planar transmission lines is presented. The formulation determines the propagation characteristics of a planar transmission line and avoids spurious non-physical modes with non-zero divergence by requiring the field to be divergenceless. Singularities in the field at perfectly conducting corners are accounted for by using singular basis functions. In addition, a set of entire-domain basis functions are developed to reduce the number of unknowns. A quasi-TEM formulation is also presented to provide a comparison with the full-wave analysis. Numerical results are provided to characterize the propagation characteristics of a microstrip transmission line. In particular, their dependence on the thickness of the microstrip and losses in the substrate is examined. In addition, the propagation characteristics of symmetric coupled microstrip transmission lines of finite thickness and the use of artificial magnetic side walls with stripline geometries are analyzed.

The purpose of this thesis was to investigate the effects of pre- and post-oxidation RCA cleaning on thin gate oxides through the study of breakdown voltages at several current levels. The RCA Clean consisted of SC1 (NH₄OH in H₂O₂), followed by an optional dilute HF dip, followed by SC2 (HCl in H₂O₂). SAS analysis of the experiments revealed the following results: an HF dip was not found to affect the performance of the pre-oxidation clean, SC2 was harmful to the oxide when performed after oxide growth, and the role of solution age was not clear. In addition, an interaction was found between SC1 and SC2 performed after oxide growth, with SC1 partially alleviating the harmful effects of SC2 when performed prior to SC2. This and other data led to the conclusion that SC2 was selectively etching the oxide.

This thesis presents a new technique, the don't-care propagation method, for logic design verification and functional error location in which a gate-level implementation of a circuit is compared with a functional-level specification. In this method, test pattern set which is generated to detect single stuck-line faults in the gate-level implementation, are used to compare the gate-level implementation with the functional-level specification. In the presence of logic design errors, such a test set will produce responses in the implementation that disagree with the responses in the specification. In the verification phase of the design of logic circuits using the top-down approach, it is necessary not only to detect but also to locate the source of any inconsistency that may exit between the functional-level specification and the gate-level implementation. The proposed technique determines the region which contains the function error. This method has very high resolution that the region usually contains a single gate or a line and therefore, reduces the time required for debugging by the designers.

This thesis describes an implementation of real-time simulation and control in the DEVS-Scheme environment. The plant is described by discrete event models developed within the event-based control paradigm. A model of the controller is employed to validate its design against a model of the plant. The same model is then migrated over to actual operation by interfacing it to a programmable sensor/actuator interface unit. A system entity structure is employed to generate both the simulation and execution versions of the controller. This methodology is supported by extensions to the DEVS-Scheme simulation environment which facilitate its use for real-time control. As an example, an intelligent controller is developed to control temperature and pressure of an oxygen production prototype system which converts carbon dioxide to oxygen. Such a system is eventually intended to operate autonomously on Mars.

The modules for processing of interconnection specifications which are provided in an input file of circuit analyzer were developed. A software package for creation of appropriate computer models on the basis of topology and library of network components was also constructed and implemented using SPICE program. A computer program, called LSPICE, has been developed by combining SPICE numerical techniques and the modal analysis of coupled transmission lines. This program can be used for simulating the transient response of networks containing coupled lossless transmission lines. Several example networks have been simulated using this program. The results have been compared with those generated by the circuit simulator program called UANTL. The LSPICE has several advantages over UANTL and SPICE in simulating the transient response of network containing coupled lossless transmission lines. A description of LSPICE and a summary of the results of numerical experiments are included.

Cartographic compilation requires precision mensuration. The calibration of mensuration processes is based on specific fiducials. External fiducials, around the exterior frame of the image, must be precisely measured to establish the overall physical geometry. Internal fiducials are provided within the image by placement of cloth panels on the ground at locations whose position is precisely known. Both types of fiducials must be known within the pixel space of a digitized image in order for the feature extraction process to be accurate with respect to delineated features. Precise mensuration of these fiducials requires that a cartographer view the image on a display and use pointing devices, such as a mouse, to pick the exact point. For accurate fiducial location, the required manual operations can be an added time-consuming task in the feature extraction process. Interactive tools which eliminate the precise pointing action for the operator are described in this thesis. The operator is required only to "box-in" the fiducial, using a simple drawing tool, select the fiducial function, and the software of the tool returns the precise location of the fiducial.

The University of Arizona Campus Internet consists of numerous Local Area Networks (LANs) attached to an Ethernet backbone. Any campus LAN which cannot interconnect with this backbone is effectively isolated. The generic gateway project was conceived to research and develop gateway systems which will help incorporate new LANs into the campus internet. The work presented here is the design, development, implementation and testing of a gateway for a selected campus LAN. The candidate LAN which was selected was the University of Arizona Sytek broadband network, which includes the Sytek LocalNet 20 and System 2000 networks.

Multiprocessor networks are widely used in the design of computer systems and telecommunication systems nowadays. And multistage interconnection networks (MINs) provide desirable high-performance and reliable interconnections, which are required in multiprocessor networks, between its processing elements (PEs) and/or memory modules (MMs). In this thesis, the augmented shuffle-exchange network (ASEN), which is a fault-tolerant MIN scheme, will be modified so as to address the problem of multi-input conflicts existing with the original proposed network scheme. The modification of ASEN has two parts. The first part is the modification of the structure of ASEN. And the second part is the development of new routing algorithm for the modified ASEN. Experimental results are provided to show that the modified augmented shuffle-exchange network (MASEN) proposed is able to enhance the MIN's ability to resolve the conflicts between multiple inputs when they occur, and the complexity of MASEN remains the same as in ASEN.

The Abel inversion is used to reconstruct an axisymmetric image from a one-dimensional projection. It finds application in a wide variety of fields, such as astronomy, optical-fiber refractive-index measurements and spray-droplet studies where the geometry is often cylindrically or spherically symmetric. However, all Abel inversion methods have drawbacks. One such arises from the singularity in the lower limit of the integral. The smoothing techniques also usually consume a large amount of computer time and the error propagation calculations are tedious. Two methods with a different approach are presented in this thesis. They are the Integral transforms and the onion-peeling method. They are both easier and simpler to compute. Also, no curve fitting is needed and the problem of handling the singularity will not arise. The noise and artifact properties of these two methods are investigated.