PMOS digital structures

A majority of new integrated circuit designs are being fabricated in CMOS technology which uses both pMOSFETs and nMOSFETS. The nMOSFETS have been well characterized over the past few years whereas the pMOSFETs have been ignored since MOS technology moved to nMOS in the early 70 \u27s. Investigation of pMOS devices will provide information that will be useful for other technologies such as CMOS. This paper looks at the design, fabrication, fabrication simulation, electrical characterization, electrical simulation and testing of digital pMOSFET circuits. A particular emphasis will be placed on understanding the process so that first time integrated circuit processors will gain the maximum knowlege and obtain working devices

Tree structures for predicting stock price behaviour

It is shown that regression trees can be used to give useful predictions of the average price movements of individual stocks when the market is regular. While the detailed error estimates may be up to three times greater for a two month prediction than for a one week average they are still less than those obtained assuming a constant price. More qualitative measures, such as the agreement in direction of movement, and local turning points are relatively independent of the period. When it is known, a posteriori, that the market has had a minor correction the model fails. This is consistent with the chaotic, fractal behaviour. With the minor correction that occurred on the ASX during April 2000 the model actually performed better in the qualitative measures than a momentum assumption

Studies of inhomogeneous superconducting states in novel materials

I provide detailed studies of two types of novel superconducting systems. In the first, I examine the effect of thermal (Gaussian) magnetic fluctuations on the superconducting transition of paramagnetically-limited superconductors under a Zeeman magnetic field. I consider transitions into both the uniform and the modulated (Fulde-Ferrell-Larkin-Ovchinnikov) superconducting states. I derive the Landau free energy expansion in powers of the superconducting order parameter, allowing for competition between the magnetic fluctuations and the superconducting order. I determine the order of the transition at the upper critical field and find that the fluctuations drive the transition, usually second-order, to first order at intermediate temperatures for both the uniform and modulated states. I also compute the thermodynamic signatures of the transition along the upper critical field. I use these results to help explain experiments on the heavy-fermion superconductor CeCoIn5, for which the superconducting transition is first-order at low temperatures and large magnetic fields. In the second study, I use a T-matrix approach to examine the resonant state generated by a single, non-magnetic impurity in multi-band superconducting systems. I consider extended s-wave symmetry of the superconducting gap and allow for anisotropy of the gap along the Fermi surface. I derive analytic expressions for the Green\u27s functions in the continuum and identify the criteria for the formation of the impurity states, emphasizing the role the band structure plays for existence of the resonant state. I then use these results to guide and explain the results of numerical studies of the impurity states on a lattice. For my numerical approach, I use dispersion relations appropriate for the description of the ferropnictides, a recently-discovered family of iron-based superconductors. I map the impurity state in real-space and emphasize how the features of these states can help identify the nodal structure of the gap on each of the Fermi surface sheets

Chaos, fractals and machine learning

The accuracy of learning a function is determined both by the underlying process that generates the sample as well as the function itself. The Lorenz butterfly, a simple weather analogy, is an example dynamical systems. Slightly more complex 6, 9 and 12, dimensional systems are also used to generate the independent variables. The non uniformly fractal distributions which are the intersection of the trajectories on a hyperplane are also used to generate variable values. As comparisons uniformly distributed (pseudo) random numbers are used as values of the independent variables. A number of functions on these hypercubes, and hyper-surfaces are defined. When the function is sampled near regions of interest and where the test set is of the same form as the learning set, both the chaotic system and fractal points have more accurate learners than the uniformly distributed ones. Using one form of distribution to learn the data, and another for testing can be particularly poor. These cross distributional results are dependent of the functional form. Aspects of machine learning relevant to fractal distributions and chaotic phenomena are developed

Through Middle Eastern eyes : the development of curriculum materials on the Middle East.

EducationDoctor of Education (EdD

Quantized Lattice Dynamic Effects on the Spin-Peierls Transition

The density matrix renormalization group method is used to investigate the spin-Peierls transition for Heisenberg spins coupled to quantized phonons. We use a phonon spectrum that interpolates between a gapped, dispersionless (Einstein) limit to a gapless, dispersive (Debye) limit. A variety of theoretical probes are used to determine the quantum phase transition, including energy gap crossing, a finite size scaling analysis, bond order auto-correlation functions, and bipartite quantum entanglement. All these probes indicate that in the antiadiabatic phonon limit a quantum phase transition of the Berezinskii-Kosterlitz-Thouless type is observed at a non-zero spin-phonon coupling, $g_{\text c}$. An extrapolation from the Einstein limit to the Debye limit is accompanied by an increase in $g_{\text c}$ for a fixed optical ($q=\pi$) phonon gap. We therefore conclude that the dimerized ground state is more unstable with respect to Debye phonons, with the introduction of phonon dispersion renormalizing the effective spin-lattice coupling for the Peierls-active mode. We also show that the staggered spin-spin and phonon displacement order parameters are unreliable means of determining the transition.Comment: To be published in Phys. Rev.

Electro-Static-Discharge (ESD) Protection in Touch and Display Driver Integrated (TDDI) Systems

This project evaluated the implications of system level electro-static discharge (ESD) on a touch and display driver integrated (TDDI) architecture component. Due to the components unique location in the system, typical component level ESD standards (JEDEC Human Body Model and Charged Device Model) were unable to adequately represent the ESD stresses seen by the integrated circuit (IC) during system level ESD testing (IEC 61000-4-2). An alternative stimulus, transmission line pulse (TLP), has been purposed as a better metric to model the devices performance under system level ESD testing and ESD devices were optimized to this stimulus