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As the size of networks increases continuously, dealing with networks with faulty nodes becomes unavoidable. In this dissertation, we introduce a new measure for network fault tolerance, the strong fault tolerance (or strong Menger-connectivity)in multicomputer networks, and study the strong fault tolerance for popular multicomputer network structures. Let G be a network in which all nodes have degree d. We say that G is strongly fault tolerant if it has the following property: Let Gf be a copy of G with at most d - 2 faulty nodes. Then for any pair of non-faulty nodes u and v in Gf , there are min{degf (u), degf (v)} node-disjoint paths in Gf from u to v, where degf (u) and degf (v) are the degrees of the nodes u and v in Gf, respectively. First we study the strong fault tolerance for the popular network structures such as star networks and hypercube networks. We show that the star networks and the hypercube networks are strongly fault tolerant and develop efficient algorithms that construct the maximum number of node-disjoint paths of nearly optimal or optimal length in these networks when they contain faulty nodes. Our algorithms are optimal in terms of their time complexity. In addition to studying the strong fault tolerance, we also investigate a more realistic concept to describe the ability of networks for tolerating faults. The traditional definition of fault tolerance, sustaining at most d - 1faulty nodes for a regular graph G of degree d, reflects a very rare situation. In many cases, there is a chance that a routing path between two given nodes can be constructed though the network may have more faulty nodes than its degree. In this dissertation, we study the fault tolerance of hypercube networks under a probability model. When each node of the n-dimensional hypercube network has an independent failure probability p, we develop algorithms that, with very high probability, can construct a fault-free path when the hypercube network can sustain up to 2np faulty nodes.

It is generally believed that the old quantum theory, as presented by Niels Bohr in 1913, fails when applied to many-electron systems, such as molecules, and nonhydrogenic atoms. It is the central theme of this dissertation to display with examples and applications the implementation of a simple and successful extension of Bohr’s planetary model of the hydrogenic atom, which has recently been developed by an atomic and molecular theory group from Texas A&M University. This ”extended” Bohr model, which can be derived from quantum mechanics using the well-known dimentional scaling technique is used to yield potential energy curves of H2 and several more complicated molecules, such as LiH, Li2, BeH, He2 and H3, with accuracies strikingly comparable to those obtained from the more lengthy and rigorous ”ab initio” computations, and the added advantage that it provides a rather insightful and pictorial description of how electrons behave to form chemical bonds, a theme not central to ”ab initio” quantum chemistry. Further investigation directed to CH, and the four-atom system H4 (with both linear and square configurations ), via the interpolated Bohr model, and the constrained Bohr model (with an effective potential), respectively, is reported. The extended model is also used to calculate correlation energies. The model is readily applicable to the study of molecular species in the presence of strong magnetic fields, as is the case in the vicinities of white dwarfs and neutron stars. We find that magnetic field increases the binding energy and decreases the bond length. Finally, an elaborative review of doubly coupled quantum dots for a derivation of the electron exchange energy, a straightforward application of Heitler-London method of quantum molecular chemistry, concludes the dissertation. The highlights of the research are (1) a bridging together of the pre- and post quantum mechanical descriptions of the chemical bond (Bohr-Sommerfeld vs Heisenberg- Schr¨odinger), and (2) the reporting of the appearance of new bound states of H2 in the presence of very strong magnetic fields. The new states emerge above the critical value of 5 × 107 G, and hence cannot be obtained perturbatively.

If there is a general theme to this thesis, it is the effects of strong correlations in both bosons and fermions. The bosonic system considered here consists of ultracold alkali atoms trapped by interfering lasers, so called optical lattices. Strong interactions, realized by increasing the depth of the lattice potential, or through the phenomenon of Feshbach resonances induce strong correlations amongst the atoms, rendering attempts to describe the systems in terms of single particle type physics unsuccessful. Of course strong correlations are not the exclusive domain of bosons, and also are not caused only by strong interactions. Other factors such as reduced dimensionality, in one-dimensional electron gases, or strong magnetic fields, in two-dimensional electron gases are known to induce strong correlations. In this thesis, we explore the manifestations of strong correlations in ultracold atoms in optical lattices and interacting electron gases. Optical lattices provide a near-perfect realization of lattice models, such as the bosonic Hubbard model (BHM) that have been formulated to study solid state systems. This follows from the absence of defects or impurities that usually plague real solid state systems. Another novel feature of optical lattices is the unprecedented control experimenters have in tuning the different lattice parameters, such as the lattice spacing and the intensity of the lasers. This control enables one to study the model Hamiltonians over a wide range of variables, such as the interaction strength between the atoms, thereby opening the door towards the observation of diverse and interesting phenomena. The BHM, and also its variants, predict various quantum phases, such as the strongly correlated Mott insulator (MI) phase that appears as a function of the parameter t/U, the ratio of the nearest neighbor hopping amplitude to the on-site interaction, which one varies experimentally over a wide range of values simply by switching the intensity of the lasers. But as always, even in these designer-made "solid state" systems, practical considerations introduce complications that blur the theoretical interpretation of experimental results, such as inhomogeneities in the lattice structure. The first part of this thesis presents a quantum theory of ultracold bosonic atoms in optical lattices capable of describing the properties of the various phases and the transitions between them. Its usefulness, compared to other approaches, we believe rests in its broad applicability and in the relative ease it handles the complications while producing quantitatively accurate results. / text

Flameless combustion technology has been developed over the past twenty years achieving low-NOx emissions and high energy efficiency for industrial applications. In the present work, three aspects of flameless combustion were examined based on a burner employing the Strong-Jet/Weak-Jet (SJ/WJ) configuration. In the first part of the work, a 3-D SJ/WJ physical model was developed in the Lagrangian perspective for an isothermal pair of free jets. The model was used to predict the WJ trajectory, identify important design/operation factors, and estimate the extent of mixing in the main combustion region (confluence region). The model was also validated with experimental data and showed excellent agreement over a wide range of flow conditions. In the second part of the work, a simplified chemical kinetic model was developed for the flameless combustion of natural gas. A detailed chemical reaction mechanism (GRI Mech 3.0) was successfully reduced to a skeletal chemical reaction mechanism under flameless combustion conditions by Principal Component Analysis, sensitivity analysis and reaction flow analysis. The skeletal mechanism was further simplified to a set of 2-D manifolds by Trajectory-Generated Low-Dimensional Manifolds (TGLDM) method. The set of 2-D manifolds was tested by the Batch Reactor (BR) and Perfect Stirred Reactor (PSR) models. From the BR model test, it was found that the chemical reaction rates were well represented by the 2-D manifolds. The effect of the physical perturbation, tested by PSR model, could be handled by the perpendicular projection instead of the orthogonal projection because both showed similar discrepancies with the skeletal mechanism. In the final part of the work, the steady-state Reynolds-Averaged Navier-Stokes (RANS) simulation was conducted for the turbulent flameless combustion in the SJ/WJ furnace, based on the Probability Density Function (PDF)/Mixing approach. The set of 2-D manifolds and Conditional Source-term Estimate (CSE) method were used for the combustion reaction and the estimation of the mean production/destruction rate, respectively. This CSE-TGLDM model provided good predictions of major species concentrations. However, the gas temperatures and CO concentrations were highly over-predicted. / Thesis (Ph.D, Chemical Engineering) -- Queen's University, 2010-09-23 11:05:21.884

This dissertation examines word-prosody of ciTonga, a Malawian Bantu language spoken by lakeshore people of northern Malawi. It is argued that the real word-prosody in this language (and perhaps many Bantu languages) revolves around the idea of Strong Accent Constituency, power relations between segments, syllables and between lower and higher prosodic categories as determined by Universal Guidelines such as SONORITY, FINALITY, EDGENESS and PROSODIC HIERARCHY as well as constraints which favour language- or context-specific Strong Accent Constituents (PROSODIC STEM, ACCENT FOOT, STEM-SYLLABLE1, PENULTIMATE SYLLABLE or FINAL SYLLABLE). Tone and prosodic morphemes such as Minimal Prosodic Words and Reduplicative Prosodic Morphemes also seem to be heavily regulated by Strong Accent Constituency. The empirical bases are three speech styles found in ciTonga (Nkhata-Bay Variety) namely, formal, common, and elderly speech styles. It is one of several understudied and endangered languages in Malawi. This study therefore is in line with one of the goals of the University of Malawi's Centre for Language Studies, where this candidate serves as a member, which is to prioritize research activities on such languages. The candidate is a native speaker of ciTonga and , as such, he is primary source of most of the data. Other methods such as elicitation and focus group discussions were conducted with informants not only to get to the bottom of the matter, but to also understand social issues underlying language variation. The dissertation has been presented in 6 chapters. Chapter 1 presents introductory remarks. These include the problem statement, a note on methodology, summary of findings, theoretical precedents, and, finally, organization of the dissertation. Chapter 2 presents basic facts about the language under study. These include language classification, previous works on ciTonga, speech sounds, the syllable, tone, as well as nominal and verbal morphology. Chapter 3 presents a proposal for the theory of Strong Accent Constituency. It presents the data on vowel and consonant deletion which motivates this theory analysis. Then attempts are made to account for the facts in terms of stress-accent theory and Downing's (2006b) Morpheme-Based Templates Theory both of which are found to be slightly problematic to account for segment deletion and preservation patterns exhibited in ciTonga. Finally, the chapter introduces the theory and accounts for the facts in terms of Strong Accent Constituent Theory. Chapter 4 presents formally the theory of Interaction between Tone and Strong Accent Constituents. The chapter presents the data on tone assignment in basic verbs, simple past tense verbs and present progressive aspect verbs which motivate this type of theory analysis. Attempts are then made to account for the facts in terms of tone alignment theory (as argued by Mtenje 2006), autosegmental accent (Clements and Goldsmith 1984) and 'pitch-accent' or accentual properties of tone in Bantu languages (as hinted upon by Downing 2004). All these theoretical perspectives are found to be slightly inadequate to account for tone distribution patterns in ciTonga. On the other hand, a theory based on Interaction between Tone and Strong Accent Constituents is shown to account for the facts slightly better. Chapter 5 presents formally proposals for Strong Accent Constituent-Based Templates as a theory of morphology-prosody interfaces in ciTonga and perhaps many other Bantu languages with a Strong Accent Constituent system. It presents the data on general phonological words, Minimal Prosodic Words and Reduplicative Prosodic Morphemes. It then reviews two competing theories in the literature within the Generalized Templates Theory namely, the Prosodic Hierarchy-Based Templates Theory and the Morpheme-Based Templates Theory both of which have a goal to account for morphology-prosody interfaces. Both these theories are shown to be slightly inadequate to account for parameters exhibited by phonological words in ciTonga. On the other hand, it is suggested that a theory of Strong Accent Constituent-Based Templates may account for the facts slightly better. Chapter 6 summarizes and concludes the dissertation.

This hermeneutical study interprets and describes the phenomena of ageing and living with disability. The lived experiences of 14 older men and the horizon of this researcher developed an understanding of what it is like for men to grow old and, for some, to live with the effects of a major disability. The study is grounded in the philosophical hermeneutics of Gadamer and framed in the context of embodiment, masculinity, and narrative. I conducted multiple in-depth interviews with older men aged from 67 to 83 years of age. Seven of the participants had experienced a stroke and I was able to explore the phenomenon of disability with them. Through thematic and narrative analyses of the textual data interpretations were developed that identified common meanings and understandings of the phenomena of ageing and disability. These themes and narratives reveal that the men�s understandings are at odds with conventional negative views of ageing and disability. These older men are �alive and kicking�, they voice counternarratives to the dominant construction of ageing as decline and weakness, and have succeeded in remaking the lifeworld after stroke. Overall I have come to understand an overarching meaning of older men �working it out� as illustrative of a strong face of ageing and disability. Older men seek out opportunities to participate actively in community life and, despite the challenges of ageing and disability, lead significant and meaningful lives. These findings challenge and extend our limited understandings of men�s experiences of ageing and living with disability. This interpretation offers gendered directions for policy development, clinical practice, and future research.

Thesis (Ph. D.)--University of Wisconsin--Madison, 1949. / Typescript. Vita. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references (leaves [122]-128).

Thesis (M.S.)--University of Wisconsin--Madison. / Typescript. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references (leaves 75-76).

Thesis (Ph. D.)--University of Texas at Austin, 2008. / Vita. Includes bibliographical references.