The genetic information required for the existence of a living cell of any kind is encoded in the sequence information scripted in the double helix DNA. A modern trend in biology struggles to come to grip with the amazing fact that there are so many different cell types in our body and that they are directed from the same genomic blueprint. It is clear, that the key to this feature is provided by epigenetic information that dictates how, where and when genes should be expressed. Epigenetic states “dress up” the genome by packaging it in chromatin conformations that differentially regulate accessibility for key nuclear factors and in coordination with differential localizations within the nucleus will dictate the ultimate task, expression. In the imprinted Igf2/H19 domain, this feature is determined by the interaction between the chromatin insulator protein CTCF and the unmethylated H19 imprinting control region. Here I show that CTCF interacts with many sites genome-wide and that these sites are generally protected from DNA methylation, suggesting that CTCF function has been recruited to manifest novel imprinted states during mammalian development. This thesis also describes the discovery of an epigenetically regulated network of intra and interchromosomal complexes, identified by the invented 4C method. Importantly, the disruption of CTCF binding sites at the H19 imprinting control region not only disconnects this network, but also leads to significant changes in expression patterns in the interacting partners. Interestingly, CTCF plays an important role in the regulation of the replication timing not only of the Igf2 gene, but also of all other sequences binding this factor potentially by a cell cycle-specific relocation of CTCF-DNA complexes to subnuclear compartments. Finally, I show that epigenetic marks signifying active or inactive states can be gained and lost, respectively, upon exposure to stress. As many genes belonging to the apoptotic pathway are upregulated we propose that stress-induced epigenetic lesions represent a surveillance system marking the affected cells for death to the benefit of the individual. This important observation opens our minds to the view of new intrinsic mechanisms that the cell has in order to maintain proper gene expression, and in the case of misleads there are several check points that direct the cell to towards important survival decisions.

In early 2002, Queensland University of Technology (QUT) commenced to develop its own low-cost Global Positioning System (GPS) receiver with the capability for space applications such as satellites in Low Earth Orbits, and sounding rockets. This is named the SPace Applications Receiver (SPARx). This receiver development is based on the Zarlink (formerly known as Mitel) GP2000 Chip set and is a modification of the Mitel Orion 12 channel receiver design. Commercially available GPS receivers for space applications are few and expensive. The QUT SPARx based on the Mitel Orion GPS receiver design is cost effective for space applications. At QUT its use is being maximized for space applications and carrier phase processing in a cost-effective and specific way. To build upon previous SPARx software developments made from 2002 to 2003, the receiver is required to be modified to have L1 carrier phase navigation capability. Such an improvement is necessary for the receiver to be used in 3-axis attitude determination and relative navigation using carrier phase. The focus of this research is on the implementation of the L1 carrier phase measurement capability with SPARx. This is to enable the use of improved navigation algorithms. Specific emphasis is given to the areas of time synchronization, the carrier phase implementation and carrier phase differential GPS with SPARx. Test results conducted in the area of time synchronization and comparisons with other carrier phase capable GPS receivers are given, as well as an investigation of the use of SPARx in carrier phase differential GPS. Following these, conclusions and recommendations are given for further improvements to SPARx.

The timing of work over the day or week is fundamental to the nature of paid work and the interaction between work and leisure. However, due to data limitations, little research has been done on the timing of work in Australia. The Australian Time Use Survey, conducted nationally by the Australian Bureau of Statistics (ABS) in 1992 and 1997, provides a unique opportunity to examine actual work timing arrangements in the Australian workforce. (For complete abstract open document)

This thesis examines the capital structure choice of Australian firms with an emphasis on the impact of market timing and liquidity considering 1438 available firms for the period, 1997 to 2005. The relationship between capital structure and its determinants is the main focus of this thesis, with four empirical analyses. These analyses are all conducted within the Baker and Wurgler (2002) and Hovakimian (2006) models with both pooled ordinary least squares (OLS) and fixed effect panel analysis. The theory of market timing introduced by Baker and Wurgler (2002) has received considerable attention in recent years. Baker and Wurgler (2002) contend that past market timing has a long lasting impact on capital structure and thus, capital structure is the cumulative outcome of the past attempts at equity market timing. This thesis examines the Baker and Wurgler (2002) argument in an Australian context. It is found that the variation in leverage was explained by the market-to-book ratio and the effect of market-to-book ratio was explained by equity issues as market timing theory implies. However, the results are sensitive to data sample choice with variation in the strength of the negative relationship observed between external finance weighted average market-to-book and leverage. This suggests that while market timing appears to affect capital structure choice, it does not support the hypothesis that past market timing decisions have a long lasting impact on Australian firm capital structure. Hovakimian ( 2006) questions the Baker and Wurgler (2002) conclusion about firm behaviour and finds evidence that past market-to-book ratio has a significant impact on current financing decisions because it contains information about growth opportunities, not captured by the current market-to-book ratio. This thesis also examines the Hovakimian (2006) argument and finds evidence to support the argument of Hovakimian (2006) that, growth opportunities provide a reasonable explanation for the past market-to-book ratio effect for Australian firms. Analysis also focuses on broad industry differences. And it is found that there are significant differences between mining and non-mining firm in the determinants of capital structure. Finally, the impact of liquidity on Australian capital structure choice is analysed within the context of the Baker and Wurgler (2002) and Hovakimian (2006) models. It is found that liquidity is important to a firm's leverage choice. There is evidence that liquid firms tend to have lower leverage. Further, while liquidity has little effect on the sensitivity of leverage to market-to-book for Baker and Wurgler (2002) filtered data, a liquidity effect is evident in a broader set of four standard deviation filtered data. It is also found that greater liquidity is associated with less sensitivity of leverage to cash flows and that the asset tangibility relation with leverage is also sensitive to liquidity. Finally, there is evidence that more liquid firms are more sensitive in their tendency to revert to some long run leverage value.

Embedded controllers coordinate the behaviours of specialised hardware components to satisfy broader application requirements. They are difficult to model and to program. One of the greatest challenges is to express intricate timing behaviours???which arise from the physical characteristics of components???while not precluding efficient implementations on resource-constrained platforms. Aspects of this challenge are addressed by this thesis through four distinct applications of timed automata and the synchronous languages Argos and Esterel. A novel framework for simulating controllers written in an imperative synchronous language is described. It includes a transformation of synchronous models into timed automata that accounts for timing properties which are important in constrained implementations but ignored by the usual assumption of synchrony. The transformation provides an interface between the discrete time of synchronous programs and a continuous model of time. This interface is extended to provide a way for simulating Argos programs within the widely-used Simulink software. Timed automata are well-suited for semantic descriptions, like the aforementioned transformation, and for modelling abstract algorithms and protocols. This thesis also includes a different type of case study. The timing diagram of a small-scale embedded component is modelled in more detail than usual with the aim of studying timing properties in this type of system. Multiple models are constructed, including one of an assembly language controller. Their interrelations are verified in Uppaal using a construction for timed trace inclusion testing. Existing constructions for testing timed trace inclusion do not directly address recent features of the Uppaal modelling language. Novel solutions for the problems presented by selection bindings, quantifiers, and channel arrays in Uppaal are presented in this thesis. The first known implementation of a tool for automatically generating a timed trace inclusion construction is described. The timed automata case study demonstrates one way of implementing application timing behaviours while respecting implementation constraints. A more challenging, but less detailed, example is proposed to evaluate the adequacy of Esterel for such tasks. Since none of the standard techniques are completely adequate, a novel alternative for expressing delays in physical time is proposed. Programs in standard Esterel are recovered through syntactic transformations that account for platform constraints.

This thesis presents an analysis of the Modified Cramer Rao Bound (MCRB) for synchroniser performance in burst mode communication applications. This is accomplished by introducing the topic of burst mode communications and its practical applications, discussing the importance of synchronisation, presenting a model through which the mathematical analysis of this thesis is based upon, deriving a set of equations which can be used to calculate the MCRB and finally by performing various calculations of the MCRB with different parameters to examine their effects on the MCRB. The methods presented in this thesis are different from those presented in existing literature, which generally do not address the issue of burst mode synchronisation directly. The differences between the methods presented in this thesis and those of existing literature is also discussed.

Thesis (Ph.D.). / Written for the Dept. of Electrical and Computer Engineering. Title from title page of PDF (viewed 2009/06/08). Includes bibliographical references.

Thesis (Ph. D.)--Virginia Polytechnic Institute and State University, 1996. / Vita. Abstract. Includes bibliographical references (leaves 161-166). Also available via the Internet.

Thesis (Ph. D.)--Oregon State University, 2007. / Printout. Includes bibliographical references (leaves 107-110). Also available online.

Hedge fund managers are characterised as either market timers or asset pickers . Their superior performance can be attributed to either timing skill, selection ability or a combination of both. In the existing literature, average hedge fund performance across the entire time span under investigation is usually investigated and measured, and hence, potentially certain subtle but important features exhibited in different time periods can be averaged out in the analysis. This thesis investigates the structural breaks in the selection ability and timing skill of hedge fund managers. This research issue is of particular importance when the hedge fund performance before, during and after the recent financial crisis is compared and contrasted. This thesis conducts a structural break analysis of hedge fund managers performance in relation to market-wide liquidity and liquidity commonality in the foreign exchange (FX) market. Liquidity commonality captures the co-movement of individual asset liquidities. The measure adopted in the existing literature has several limitations. This thesis proposes a new measure, termed the Beta Index, which is derived from the time-varying exposure of individual liquidities to market liquidity movements. It is shown that the developed Beta Index is more able to identify the level of liquidity commonality in the FX market. It is also more flexible in measuring commonality with different data sampling frequency. The obtained empirical results have some practical implications. They show that the selection skill and timing ability of hedge fund managers are subject to regime switches. Under severe market conditions, most hedge fund managers possess the skill to time FX market-wide liquidity and are able to reduce losses from the FX market by reducing their funds FX exposure prior to the FX market-wide liquidity deteriorations. In the meantime, most hedge fund managers are able to deliver excess returns from time to time due to their selection ability. However, when sudden shocks of crisis occur, they fail to forecast the unexpected behaviour in the price of individual assets underlying the funds and display unsuccessful selection ability. In addition, the results suggest that many hedge funds are exposed to the FX liquidity commonality risk which impairs hedging strategies and diversification performance.