The main content of this thesis concerns a tableau method for solving the satisfiability problem for the modal μ-calculus. A sound and complete tableau system for the modal μ-calculus is given. Since every tableau in such tableau system is finite and bounded by the length of the formula, the tableau system may be used as a decision procedure for determining the satisfiability of the formula. An alternative proof of the small model property is obtained: every satisfiable formula has a model of size singleexponential in the length of the formula. Contrary to known proofs in literature, the results presented here do not rely on automata theory. Two simplifications of the tableau system are given. One is for the class of aconjunctive formulae. The resulting tableau system has been used to prove the completeness of Kozen’s axiomatisation with respect to the aconjunctive fragment of the modal μ- calculus. Another is for the formulae in the class Πμ 2 . In addition to the tableau method, the thesis explores some model-surgery techniques with the aim that such techniques may be used to directly prove the small model theorem. The techniques obtained so far have been used to show the small model property for Πμ 2 -formulae and for formulae with linear models.

Until this present work, the acoustics of waveguides has been divided into two broadly distinct fields---linear acoustics in ducts of complex geometry such as those with curvature or varying width, and nonlinear acoustics restricted to simple geometry ducts without curvature or flare. This PhD unites these distinct branches to give a complete mathematical description of weakly nonlinear wave propagation in a general shaped duct in both two and three dimensions. Such ducts have important applications---the clearest example is that of brass instruments, where it has been demonstrated that nonlinear wave steepening gives rise to the characteristic 'brassy' sounds of, for example, the trombone. As the ducts of these instruments have a very complicated geometry involving curvature, torsion and varying width, the goal of the PhD is to address what effect, if any, such changes in duct geometry have on the acoustic properties of such instruments. Other potential applications include the study of acoustics in curved aircraft engine intakes and even the nonlinear sound propagation through the trunk of an elephant. The first results chapter is focused on the exposition of the method used for the remainder of the paper, with the introduction of a new ``nonlinear admittance term'' as well as the associated algebra for it. An elegant notation for the nonlinear algebra is also developed, greatly simplifying the equations. The method is applied to one and two dimensional ducts and some analytical results are derived relating the work to previously published results. Numerical results are also presented and compared to other sources. The concept of nonlinear reflectance is also introduced---illustrating the effect of wave amplitude on the amount of energy reflected in a duct. The next results chapter builds on this work extending it to three dimensions. Numerical results are presented for three characteristic ducts---a curved duct, a horn and a helical duct, being one of the first works to study acoustics in helical pipes for both linear and nonlinear sound propagation. The final results chapter, utilising all of the previous work, addresses the problem of an open ended duct of finite length with nonlinear effects included. Results are compared with the linear results from the Wiener-Hopf method and new results are presented illustrating the effect of geometry and nonlinearity on the resonances of finite length waveguides culminating in the study of the resonances of a trombone.

Neuroplasticity is a mechanism whereby the brain changes its configuration and function through experience. Short-term learning (i.e. minutes to hours) is associated with early phases of neuroplasticity whereby the cortical responses increase to common stimuli, and underlies long-term learning (i.e. days to weeks). Tactile sensation is an important sense, therefore if it became compromised it would be valuable to have an understanding of the neural mechanisms that underlie tactile short-term learning, and other means to promote learning, such as the introduction of a second modality. Having more knowledge in the area of somatosensory learning could then provide the means leading to long-term learning and potential recovery of function after brain injury such as stroke. The focus of this thesis was to research the role of visual information on short-term somatosensory learning, and to understand the electrophysiological mechanisms that are associated with this modulation of learning within a single testing session. The methodology consisted of learning Morse code tactile patterns corresponding to English letters, and was broken up into two experiments. The objective of the first experiment was to determine the functional benefit to performance of the temporal and spatial coupling of tactile and visual stimuli, and the second experiment was used to determine the electrophysiological mechanisms associated with the modulation of somatosensory processing by visual stimulation. Given that there is a quantifiable measurement of learning, we hypothesized that tactile-visual cross-modal coupling will increase the learning outcome and provide functional benefit. It has been shown (Eimer et al., 2001) that presenting a visual stimulus within the same spatial site as the corresponding tactile stimulus will enhance the measurable components, and better the behavioural performance (Ohara et al., 2006). The current results demonstrated that visual-tactile cross-modal association can have a positive effect on learning over a short period of time, and that presenting a visual stimulus prior to a tactile stimulus may be beneficial to performance during the early stages of learning. Also, the results from the second experiment demonstrated an elevated and prolonged tactile P100, and a noticeably absent N140 component when tactile information was presented before visual information. Further research, extending from this thesis, is needed to advance understanding of the performance and electrophysiological outcomes of visual-tactile cross-modal associations. The findings of this study give insight into the performance and electrophysiological effects involved with short-term somatosensory learning, specifically how the manipulation of a visual stimulus, both spatially and temporally, can affect tactile learning as indicated through behavioural performance, and affect the electrophysiological mechanisms involved with somatosensory processing.

Neuroplasticity is a mechanism whereby the brain changes its configuration and function through experience. Short-term learning (i.e. minutes to hours) is associated with early phases of neuroplasticity whereby the cortical responses increase to common stimuli, and underlies long-term learning (i.e. days to weeks). Tactile sensation is an important sense, therefore if it became compromised it would be valuable to have an understanding of the neural mechanisms that underlie tactile short-term learning, and other means to promote learning, such as the introduction of a second modality. Having more knowledge in the area of somatosensory learning could then provide the means leading to long-term learning and potential recovery of function after brain injury such as stroke. The focus of this thesis was to research the role of visual information on short-term somatosensory learning, and to understand the electrophysiological mechanisms that are associated with this modulation of learning within a single testing session. The methodology consisted of learning Morse code tactile patterns corresponding to English letters, and was broken up into two experiments. The objective of the first experiment was to determine the functional benefit to performance of the temporal and spatial coupling of tactile and visual stimuli, and the second experiment was used to determine the electrophysiological mechanisms associated with the modulation of somatosensory processing by visual stimulation. Given that there is a quantifiable measurement of learning, we hypothesized that tactile-visual cross-modal coupling will increase the learning outcome and provide functional benefit. It has been shown (Eimer et al., 2001) that presenting a visual stimulus within the same spatial site as the corresponding tactile stimulus will enhance the measurable components, and better the behavioural performance (Ohara et al., 2006). The current results demonstrated that visual-tactile cross-modal association can have a positive effect on learning over a short period of time, and that presenting a visual stimulus prior to a tactile stimulus may be beneficial to performance during the early stages of learning. Also, the results from the second experiment demonstrated an elevated and prolonged tactile P100, and a noticeably absent N140 component when tactile information was presented before visual information. Further research, extending from this thesis, is needed to advance understanding of the performance and electrophysiological outcomes of visual-tactile cross-modal associations. The findings of this study give insight into the performance and electrophysiological effects involved with short-term somatosensory learning, specifically how the manipulation of a visual stimulus, both spatially and temporally, can affect tactile learning as indicated through behavioural performance, and affect the electrophysiological mechanisms involved with somatosensory processing.

Modal parameter identification of a structure is done through modal testing and modal analysis using various system identification methods. These methods employ linear input-output relationships to extract the modes of a structure. There are cases where laboratory testing of a structure is not possible or information about the structure under operating conditions is seeked. A set of techniques called Operational Modal Analysis have been developed for modal parameter identification in operating conditions of a structure. These techniques use only response measurements to extract the modes. The aim of this study is to investigate the applicability and use of three selected time-domain methods adapted to operational modal analysis. The algorithms are programmed in Matlab&copy / environment, and various cases are evaluated using computer simulations for each method. Two of the selected methods are evaluated on a laboratory scale test setup.

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This thesis is concerned with the problem of construction of the logical structure of a persuasive discourse. A persuasive discourse can be defined as a monodirectional form of communication, generated by a speaker in order to convince a hearer about the validity (or fallacy) of a specific belief The construction of the structure of a persuasive discourse is realized, in this work, through the adoption of two basic elements: a belief system and a planning system. The planning system is used as a tool for the automatic generation of the discourse structure (or plan), obtained through the decomposition of the assigned (communicative) goals of persuasion, aimed at producing specific effects on the hearer’s beliefs. The belief system is adopted in order to endow the planning process with a formal language of beliefs for the representation of such goals, and with the mechanisms which govern the propagation of their (expected) effects on the rest of the hearer's belief state. The main results presented consist of the formalization of a paradigm for specification of belief systems, and of a method — whose correctness is formally proved — for their integration with planning systems. The formalization of a belief system for discourse structure representation (defined in accordance with the theoretical paradigm) is also given, together with the description of its implementation and integration with a specific planner, which resulted in the actual completion of a system for the automatic generation of persuasive discourse plans.

In 2001, Australia's annual freight movement load reached 310 billion million tonne-kilometres. By 2020, it is forecast to be 630 billion tonnes-kilometres, an expected rise of slightly over 100 percent of the current level. Due to accelerating freight movement demand in Australia, a rising need for efficient transport infrastructure can be expected. Terminals are a vital part of transport systems which affect the development of whole regions. Terminal location is therefore essential in evaluating the extent to which terminals play a positive role in shaping regional development. Inter-modal freight transportation is defined as a system that carries freight from origin to destination by using two or more transportation modes. Inter-modal terminal location has great bearing on, and is influenced by, infrastructural efficiency. Terminal locations should optimize both the potential impacts of regional development and effects on transport development. Consequently, it is imperative to analyse the interaction of locations and effects in the process of optimizing terminal location. This research aims to define the effects of terminal location on transportation by studying the different inter-modal system of the top Australia ports, and introducing the relationship between these effects and transport strategic modelling. Data on transport modelling elements will be investigated in four case studies, followed by data sensitivity analysis to assess the way in which terminal location affects transportation performance. To examine the effects of terminal location factor on transportation, a number of key elements were selected by the Inter-modal Freight Transport and Regional Development Model and Strategic Modelling: Attractiveness, Location Decisions of Firms, Economic Activity, Shipping/Trip Decision, Destination Choice, Mode Choice, Route Choice, Link Loads, Link Times/Distances/Costs and Accessibility. Environmental issue of a terminal are an additional important consideration in freight movement, when presented as a cost of using the terminal. The outcome of the case studies which make up this research is a statement of the main effects of the studied elements on terminal location and the potentially necessary improvements to the ports studied For example, 20 kilometres seems to be the radius of an inter-modal terminal catchment level and rail service in Victoria is therefore recommended to be increased to take into account environmental issues. This is augmented by two further studies of the In-land Port and Accessibility of the Port of Brisbane. In essence, this thesis is an attempt to make Australian transport and social services planners aware of the effects of factors relating to terminal location in the processes of evaluating the optimum terminal location.

Thesis (M.S.)--Virginia Polytechnic Institute and State University, 1992. / Vita. Abstract. Includes bibliographical references (leaves 189-192). Also available via the Internet.

Thesis (M.S.)--Virginia Polytechnic Institute and State University, 1992. / Vita. Abstract. Includes bibliographical references (leaves 133-135). Also available via the Internet.