Statistical analysis and reduction of multiple access interference in MC-CDMA systems

Multicarrier code division multiple access (MC-CDMA) is a very promising candidate for the multiple access scheme in fourth generation wireless communi- cation systems. During asynchronous transmission, multiple access interference (MAI) is a major challenge for MC-CDMA systems and significantly affects their performance. The main objectives of this thesis are to analyze the MAI in asyn- chronous MC-CDMA, and to develop robust techniques to reduce the MAI effect. Focus is first on the statistical analysis of MAI in asynchronous MC-CDMA. A new statistical model of MAI is developed. In the new model, the derivation of MAI can be applied to different distributions of timing offset, and the MAI power is modelled as a Gamma distributed random variable. By applying the new statistical model of MAI, a new computer simulation model is proposed. This model is based on the modelling of a multiuser system as a single user system followed by an additive noise component representing the MAI, which enables the new simulation model to significantly reduce the computation load during computer simulations. MAI reduction using slow frequency hopping (SFH) technique is the topic of the second part of the thesis. Two subsystems are considered. The first sub- system involves subcarrier frequency hopping as a group, which is referred to as GSFH/MC-CDMA. In the second subsystem, the condition of group hopping is dropped, resulting in a more general system, namely individual subcarrier frequency hopping MC-CDMA (ISFH/MC-CDMA). This research found that with the introduction of SFH, both of GSFH/MC-CDMA and ISFH/MC-CDMA sys- tems generate less MAI power than the basic MC-CDMA system during asyn- chronous transmission. Because of this, both SFH systems are shown to outper- form MC-CDMA in terms of BER. This improvement, however, is at the expense of spectral widening. In the third part of this thesis, base station polarization diversity, as another MAI reduction technique, is introduced to asynchronous MC-CDMA. The com- bined system is referred to as Pol/MC-CDMA. In this part a new optimum com- bining technique namely maximal signal-to-MAI ratio combining (MSMAIRC) is proposed to combine the signals in two base station antennas. With the applica- tion of MSMAIRC and in the absents of additive white Gaussian noise (AWGN), the resulting signal-to-MAI ratio (SMAIR) is not only maximized but also in- dependent of cross polarization discrimination (XPD) and antenna angle. In the case when AWGN is present, the performance of MSMAIRC is still affected by the XPD and antenna angle, but to a much lesser degree than the traditional maximal ratio combining (MRC). Furthermore, this research found that the BER performance for Pol/MC-CDMA can be further improved by changing the angle between the two receiving antennas. Hence the optimum antenna angles for both MSMAIRC and MRC are derived and their effects on the BER performance are compared. With the derived optimum antenna angle, the Pol/MC-CDMA system is able to obtain the lowest BER for a given XPD.

A study into the permeability and compressibility of Australian bagasse pulp

This is an experimental study into the permeability and compressibility properties of bagasse pulp pads. Three experimental rigs were custom-built for this project. The experimental work is complemented by modelling work. Both the steady-state and dynamic behaviour of pulp pads are evaluated in the experimental and modelling components of this project. Bagasse, the fibrous residue that remains after sugar is extracted from sugarcane, is normally burnt in Australia to generate steam and electricity for the sugar factory. A study into bagasse pulp was motivated by the possibility of making highly value-added pulp products from bagasse for the financial benefit of sugarcane millers and growers. The bagasse pulp and paper industry is a multibillion dollar industry (1). Bagasse pulp could replace eucalypt pulp which is more widely used in the local production of paper products. An opportunity exists for replacing the large quantity of mainly generic paper products imported to Australia. This includes 949,000 tonnes of generic photocopier papers (2). The use of bagasse pulp for paper manufacture is the main application area of interest for this study. Bagasse contains a large quantity of short parenchyma cells called ‘pith’. Around 30% of the shortest fibres are removed from bagasse prior to pulping. Despite the ‘depithing’ operations in conventional bagasse pulp mills, a large amount of pith remains in the pulp. Amongst Australian paper producers there is a perception that the high quantity of short fibres in bagasse pulp leads to poor filtration behaviour at the wet-end of a paper machine. Bagasse pulp’s poor filtration behaviour reduces paper production rates and consequently revenue when compared to paper production using locally made eucalypt pulp. Pulp filtration can be characterised by two interacting factors; permeability and compressibility. Surprisingly, there has previously been very little rigorous investigation into neither bagasse pulp permeability nor compressibility. Only freeness testing of bagasse pulp has been published in the open literature. As a result, this study has focussed on a detailed investigation of the filtration properties of bagasse pulp pads. As part of this investigation, this study investigated three options for improving the permeability and compressibility properties of Australian bagasse pulp pads. Two options for further pre-treating depithed bagasse prior to pulping were considered. Firstly, bagasse was fractionated based on size. Two bagasse fractions were produced, ‘coarse’ and ‘medium’ bagasse fractions. Secondly, bagasse was collected after being processed on two types of juice extraction technology, i.e. from a sugar mill and from a sugar diffuser. Finally one method of post-treating the bagasse pulp was investigated. The effects of chemical additives, which are known to improve freeness, were also assessed for their effect on pulp pad permeability and compressibility. Pre-treated Australian bagasse pulp samples were compared with several benchmark pulp samples. A sample of commonly used kraft Eucalyptus globulus pulp was obtained. A sample of depithed Argentinean bagasse, which is used for commercial paper production, was also obtained. A sample of Australian bagasse which was depithed as per typical factory operations was also produced for benchmarking purposes. The steady-state pulp pad permeability and compressibility parameters were determined experimentally using two purpose-built experimental rigs. In reality, steady-state conditions do not exist on a paper machine. The permeability changes as the sheet compresses over time. Hence, a dynamic model was developed which uses the experimentally determined steady-state permeability and compressibility parameters as inputs. The filtration model was developed with a view to designing pulp processing equipment that is suitable specifically for bagasse pulp. The predicted results of the dynamic model were compared to experimental data. The effectiveness of a polymeric and microparticle chemical additives for improving the retention of short fibres and increasing the drainage rate of a bagasse pulp slurry was determined in a third purpose-built rig; a modified Dynamic Drainage Jar (DDJ). These chemical additives were then used in the making of a pulp pad, and their effect on the steady-state and dynamic permeability and compressibility of bagasse pulp pads was determined. The most important finding from this investigation was that Australian bagasse pulp was produced with higher permeability than eucalypt pulp, despite a higher overall content of short fibres. It is thought this research outcome could enable Australian paper producers to switch from eucalypt pulp to bagasse pulp without sacrificing paper machine productivity. It is thought that two factors contributed to the high permeability of the bagasse pulp pad. Firstly, thicker cell walls of the bagasse pulp fibres resulted in high fibre stiffness. Secondly, the bagasse pulp had a large proportion of fibres longer than 1.3 mm. These attributes helped to reinforce the pulp pad matrix. The steady-state permeability and compressibility parameters for the eucalypt pulp were consistent with those found by previous workers. It was also found that Australian pulp derived from the ‘coarse’ bagasse fraction had higher steady-state permeability than the ‘medium’ fraction. However, there was no difference between bagasse pulp originating from a diffuser or a mill. The bagasse pre-treatment options investigated in this study were not found to affect the steady-state compressibility parameters of a pulp pad. The dynamic filtration model was found to give predictions that were in good agreement with experimental data for pads made from samples of pretreated bagasse pulp, provided at least some pith was removed prior to pulping. Applying vacuum to a pulp slurry in the modified DDJ dramatically reduced the drainage time. At any level of vacuum, bagasse pulp benefitted from chemical additives as quantified by reduced drainage time and increased retention of short fibres. Using the modified DDJ, it was observed that under specific conditions, a benchmark depithed bagasse pulp drained more rapidly than the ‘coarse’ bagasse pulp. In steady-state permeability and compressibility experiments, the addition of chemical additives improved the pad permeability and compressibility of a benchmark bagasse pulp with a high quantity of short fibres. Importantly, this effect was not observed for the ‘coarse’ bagasse pulp. However, dynamic filtration experiments showed that there was also a small observable improvement in filtration for the ‘medium’ bagasse pulp. The mechanism of bagasse pulp pad consolidation appears to be by fibre realignment. Chemical additives assist to lubricate the consolidation process. This study was complemented by pulp physical and chemical property testing and a microscopy study. In addition to its high pulp pad permeability, ‘coarse’ bagasse pulp often (but not always) had superior physical properties than a benchmark depithed bagasse pulp.

Improved GrabCut segmentation via GMM optimisation

Semi-automatic segmentation of still images has vast and varied practical applications. Recently, an approach "GrabCut" has managed to successfully build upon earlier approaches based on colour and gradient information in order to address the problem of efficient extraction of a foreground object in a complex environment. In this paper, we extend the GrabCut algorithm further by applying an unsupervised algorithm for modelling the Gaussian Mixtures that are used to define the foreground and background in the segmentation algorithm. We show examples where the optimisation of the GrabCut framework leads to further improvements in performance.

Computer vision onboard UAVs for civilian tasks

Computer vision is much more than a technique to sense and recover environmental information from an UAV. It should play a main role regarding UAVs’ functionality because of the big amount of information that can be extracted, its possible uses and applications, and its natural connection to human driven tasks, taking into account that vision is our main interface to world understanding. Our current research’s focus lays on the development of techniques that allow UAVs to maneuver in spaces using visual information as their main input source. This task involves the creation of techniques that allow an UAV to maneuver towards features of interest whenever a GPS signal is not reliable or sufficient, e.g. when signal dropouts occur (which usually happens in urban areas, when flying through terrestrial urban canyons or when operating on remote planetary bodies), or when tracking or inspecting visual targets—including moving ones—without knowing their exact UMT coordinates. This paper also investigates visual serving control techniques that use velocity and position of suitable image features to compute the references for flight control. This paper aims to give a global view of the main aspects related to the research field of computer vision for UAVs, clustered in four main active research lines: visual serving and control, stereo-based visual navigation, image processing algorithms for detection and tracking, and visual SLAM. Finally, the results of applying these techniques in several applications are presented and discussed: this study will encompass power line inspection, mobile target tracking, stereo distance estimation, mapping and positioning.

Simulation and enhancement of a cardiovascular device test rig

Cardiovascular assist devices are tested in mock circulation loops (MCLs) prior to animal and clinical testing. These MCLs rely on characteristics such as pneumatic parameters to create pressure and flow, and pipe dimensions to replicate the resistance, compliance and fluid inertia of the natural cardiovascular system. A mathematical simulation was developed in SIMULINK to simulate an existing MCL. Model validation was achieved by applying the physical MCL characteristics to the simulation and comparing the resulting pressure traces. These characteristics were subsequently altered to improve and thus predict the performance of a more accurate physical system. The simulation was successful in simulating the physical mock circulation loop, and proved to be a useful tool in the development of improved cardiovascular device test rigs.

Defining the public interests in airport development decision-making

Residents, businesses, local, state and national government stakeholders all want to have their say when airports expand or develop. While stakeholder engagement is increasingly a strategy employed for managing the tensions attracted to airport development, different stakeholders have different expectations and demands of airports. This requires different approaches to stakeholder engagement. Identifying the public interests that are at stake in developing airports provides an initial step towards building a platform for selecting and applying stakeholder engagement strategies in airport and more general infrastructure contexts. This paper uses the existing literature of public interests and values to build a general typology of public values for the stakeholders of airport development. A range of semi-privatised and state owned airport case studies from Europe have been used to demonstrate the universal nature of the identified values. The result is a framework that identifies both the substantive and procedural values, separated into local, state/regional and national levels of interest. The typology provides a generalised view of public interests in airport development; however, the public interests identified may be limited to more western oriented societies due to the skew of airport cases reviewed. Contributions are made to the literature with a typology of public values derived from existing knowledge and explored using empirical case examples. The provided typology enables research of airport development decision-making to delineate public interests both within and between stakeholder groups, and helps to explain the different perspectives that stakeholders have towards airport development. Future research may focus on refining the typology for different types of airport governance structures, such as differences between public values in state and market-led airport development; include more airport cases from eastern societies to draw parallels or differences between western and eastern societies; or utilise the typology as a framework for analysing changes in public interests of airports over time.

Empirical measurement of the Enright phenomenon, a distortion of perceived driving speed

Purpose: In 1970, Enright observed a distortion of perceived driving speed, induced by monocular application of a neutral density (ND) filter. If a driver looks out of the right side of a vehicle with a filter over the right eye, the driver perceives a reduction of the vehicle’s apparent velocity, while applying a ND filter over the left eye increases the vehicle’s apparent velocity. The purpose of the current study was to provide the first empirical measurements of the Enright phenomenon. Methods: Ten experienced drivers were tested and drove an automatic sedan on a closed road circuit. Filters (0.9 ND) were placed over the left, right or both eyes during a driving run, in addition to a control condition with no filters in place. Subjects were asked to look out of the right side of the car and adjust their driving speed to either 40 km/h or 60 km/h. Results: Without a filter or with both eyes filtered subjects showed good estimation of speed when asked to travel at 60 km/h but travelled a mean of 12 to 14 km/h faster than the requested 40 km/h. Subjects travelled faster than these baselines by a mean of 7 to 9 km/h (p < 0.001) with the filter over their right eye, and 3 to 5 km/h slower with the filter over their left eye (p < 0.05). Conclusions: The Enright phenomenon causes significant and measurable distortions of perceived driving speed under realworld driving conditions.

Beyond charity : outlines of a jurisprudence for civil society

There is not a single, coherent, jurisprudence for civil society organisations. Pressure for a clearly enuciated body of law applying to the whole of this sector of society continues to increase. The rise of third sector scholarship, the retreat of the welfare state, the rediscovery of the concept of civil society and pressures to strengthen social capital have all contributed to an ongoing stream of inquiry into the laws that regulate and favour civil society organisations. There have been almost thirty inquiries over the last sixty years into the doctrine of charitable purpose in common law countries. Those inquiries have established that problems with the law applying to civil society organisations are rooted in the common law adopting a ‘technical’ definition of charitable purpose and the failure of this body of law to develop in response to societal changes. Even though it is now well recognised that problems with law reform stem from problems inherent in the doctrine of charitable purpose, statutory reforms have merely ‘bolted on’ additions to the flawed ‘technical’ definition. In this way the scope of operation of the law has been incrementally expanded to include a larger number of civil society organisations. This piecemeal approach continues the exclusion of most civil society organisations from the law of charities discourse, and fails to address the underlying jurisprudential problems. Comprehensive reform requires revisiting the foundational problems embedded in the doctrine of charitable purpose, being informed by recent scholarship, and a paradigm shift that extends the doctrine to include all civil society organisations. Scholarly inquiry into civil society organisations, particularly from within the discipline of neoclassical economics, has elucidated insights that can inform legal theory development. This theory development requires decoupling the two distinct functions performed by the doctrine of charitable purpose which are: setting the scope of regulation, and determining entitlement to favours, such as tax exemption. If the two different functions of the doctrine are considered separately in the light of theoretical insights from other disciplines, the architecture for a jurisprudence emerges that facilitates regulation, but does not necessarily favour all civil society organisations. Informed by that broader discourse it is argued that when determining the scope of regulation, civil society organisations are identified by reference to charitable purposes that are not technically defined. These charitable purposes are in essence purposes which are: Altruistic, for public Benefit, pursued without Coercion. These charitable puposes differentiate civil society organisations from organisations in the three other sectors namely; Business, which is manifest in lack of altruism; Government, which is characterised by coercion; and Family, which is characterised by benefits being private not public. When determining entitlement to favour, it is theorised that it is the extent or nature of the public benefit evident in the pursuit of a charitable purpose that justifies entitlement to favour. Entitlement to favour based on the extent of public benefit is the theoretically simpler – the greater the public benefit the greater the justification for favour. To be entitled to favour based on the nature of a purpose being charitable the purpose must fall within one of three categories developed from the first three heads of Pemsel’s case (the landmark categorisation case on taxation favour). The three categories proposed are: Dealing with Disadvantage, Encouraging Edification; and Facilitating Freedom. In this alternative paradigm a recast doctrine of charitable purpose underpins a jurisprudence for civil society in a way similar to the way contract underpins the jurisprudence for the business sector, the way that freedom from arbitrary coercion underpins the jurisprudence of the government sector and the way that equity within families underpins succession and family law jurisprudence for the family sector. This alternative architecture for the common law, developed from the doctrine of charitable purpose but inclusive of all civil society purposes, is argued to cover the field of the law applying to civil society organisations and warrants its own third space as a body of law between public law and private law in jurisprudence.

Addressing issues in sparseness, ecological bias and formulation of the adjacency matrix in Bayesian spatio-temporal analysis of disease counts

The main objective of this PhD was to further develop Bayesian spatio-temporal models (specifically the Conditional Autoregressive (CAR) class of models), for the analysis of sparse disease outcomes such as birth defects. The motivation for the thesis arose from problems encountered when analyzing a large birth defect registry in New South Wales. The specific components and related research objectives of the thesis were developed from gaps in the literature on current formulations of the CAR model, and health service planning requirements. Data from a large probabilistically-linked database from 1990 to 2004, consisting of fields from two separate registries: the Birth Defect Registry (BDR) and Midwives Data Collection (MDC) were used in the analyses in this thesis. The main objective was split into smaller goals. The first goal was to determine how the specification of the neighbourhood weight matrix will affect the smoothing properties of the CAR model, and this is the focus of chapter 6. Secondly, I hoped to evaluate the usefulness of incorporating a zero-inflated Poisson (ZIP) component as well as a shared-component model in terms of modeling a sparse outcome, and this is carried out in chapter 7. The third goal was to identify optimal sampling and sample size schemes designed to select individual level data for a hybrid ecological spatial model, and this is done in chapter 8. Finally, I wanted to put together the earlier improvements to the CAR model, and along with demographic projections, provide forecasts for birth defects at the SLA level. Chapter 9 describes how this is done. For the first objective, I examined a series of neighbourhood weight matrices, and showed how smoothing the relative risk estimates according to similarity by an important covariate (i.e. maternal age) helped improve the model’s ability to recover the underlying risk, as compared to the traditional adjacency (specifically the Queen) method of applying weights. Next, to address the sparseness and excess zeros commonly encountered in the analysis of rare outcomes such as birth defects, I compared a few models, including an extension of the usual Poisson model to encompass excess zeros in the data. This was achieved via a mixture model, which also encompassed the shared component model to improve on the estimation of sparse counts through borrowing strength across a shared component (e.g. latent risk factor/s) with the referent outcome (caesarean section was used in this example). Using the Deviance Information Criteria (DIC), I showed how the proposed model performed better than the usual models, but only when both outcomes shared a strong spatial correlation. The next objective involved identifying the optimal sampling and sample size strategy for incorporating individual-level data with areal covariates in a hybrid study design. I performed extensive simulation studies, evaluating thirteen different sampling schemes along with variations in sample size. This was done in the context of an ecological regression model that incorporated spatial correlation in the outcomes, as well as accommodating both individual and areal measures of covariates. Using the Average Mean Squared Error (AMSE), I showed how a simple random sample of 20% of the SLAs, followed by selecting all cases in the SLAs chosen, along with an equal number of controls, provided the lowest AMSE. The final objective involved combining the improved spatio-temporal CAR model with population (i.e. women) forecasts, to provide 30-year annual estimates of birth defects at the Statistical Local Area (SLA) level in New South Wales, Australia. The projections were illustrated using sixteen different SLAs, representing the various areal measures of socio-economic status and remoteness. A sensitivity analysis of the assumptions used in the projection was also undertaken. By the end of the thesis, I will show how challenges in the spatial analysis of rare diseases such as birth defects can be addressed, by specifically formulating the neighbourhood weight matrix to smooth according to a key covariate (i.e. maternal age), incorporating a ZIP component to model excess zeros in outcomes and borrowing strength from a referent outcome (i.e. caesarean counts). An efficient strategy to sample individual-level data and sample size considerations for rare disease will also be presented. Finally, projections in birth defect categories at the SLA level will be made.

Resistance : re-imagining innovation in higher education teaching and learning

The call to innovate is ubiquitous across the Australian educational policy context. The claims of innovative practices and environments that occur frequently in university mission statements, strategic plans and marketing literature suggest that this exhortation to innovate appears to have been taken up enthusiastically by the university sector. Throughout the history of universities, a range of reported deficiencies of higher education have worked to produce a notion of crisis. At present, it would seem that innovation is positioned as the solution to the notion of crisis. This thesis is an inquiry into how the insistence on innovation works to both enable and constrain teaching and learning practices in Australian universities. Alongside the interplay between innovation and crisis is the link between resistance and innovation, a link which remains largely unproblematized in the scholarly literature. This thesis works to locate and unsettle understandings of a relationship between innovation and Australian higher education. The aim of this inquiry is to generate new understandings of what counts as innovation within this context and how innovation is enacted. The thesis draws on a number of postmodernist theorists, whose works have informed firstly the research method, and then the analysis and findings. Firstly, there is an assumption that power is capillary and works through discourse to enact power relations which shape certain truths (Foucault, 1990). Secondly, this research scrutinised language practices which frame the capacity for individuals to act, alongside the language practices which encourage an individual to adopt certain attitudes and actions as one’s own (Foucault, 1988). Thirdly, innovation talk is read in this thesis as an example of needs talk, that is, as a medium through which what is considered domestic, political or economic is made and contested (Fraser, 1989). Fourthly, relationships between and within discourses were identified and analysed beyond cause and effect descriptions, and more productively considered to be in a constant state of becoming (Deleuze, 1987). Finally, the use of ironic research methods assisted in producing alternate configurations of innovation talk which are useful and new (Rorty, 1989). The theoretical assumptions which underpin this thesis inform a document analysis methodology, used to examine how certain texts work to shape the ways in which innovation is constructed. The data consisted of three Federal higher education funding policies selected on the rationale that these documents, as opposed to state or locally based policy and legislation, represent the only shared policy context for all Australian universities. The analysis first provided a modernist reading of the three documents, and this was followed by postmodernist readings of these same policy documents. The modernist reading worked to locate and describe the current truths about innovation. The historical context in which the policy was produced as well as the textual features of the document itself were important to this reading. In the first modernist reading, the binaries involved in producing proper and improper notions of innovation were described and analysed. In the process of the modernist analysis and the subsequent location of binary organisation, a number of conceptual collisions were identified, and these sites of struggle were revisited, through the application of a postmodernist reading. By applying the theories of Rorty (1989) and Fraser (1989) it became possible to not treat these sites as contradictory and requiring resolution, but rather as spaces in which binary tensions are necessary and productive. This postmodernist reading constructed new spaces for refusing and resisting dominant discourses of innovation which value only certain kinds of teaching and learning practices. By exploring a number of ironic language practices found within the policies, this thesis proposes an alternative way of thinking about what counts as innovation and how it happens. The new readings of innovation made possible through the work of this thesis were in response to a suite of enduring, inter-related questions – what counts as innovation?, who or what supports innovation?, how does innovation occur?, and who are the innovators?. The truths presented in response to these questions were treated as the language practices which constitute a dominant discourse of innovation talk. The collisions that occur within these truths were the contested sites which were of most interest for the analysis. The thesis concludes by presenting a theoretical blueprint which works to shift the boundaries of what counts as innovation and how it happens in a manner which is productive, inclusive and powerful. This blueprint forms the foundation upon which a number of recommendations are made for both my own professional practice and broader contexts. In keeping with the conceptual tone of this study, these recommendations are a suite of new questions which focus attention on the boundaries of innovation talk as an attempt to re-configure what is valued about teaching and learning at university.

Community engagement : exploring a relational approach to consultation and collaborative practice in Australia

Community engagement is increasingly being employed by Australian organizations as a key strategy to incorporate representative community opinions into decision-making. This trend is reflected by Australian local and state governments legislating for community consultation in major infrastructure projects and the increasing role of public relations practitioners to manage these programs. This study explores community engagement founded on relational theory and proposed a typology of engagement employing a relational framework. An exploratory study of 20 Australian infrastructure projects with a mandatory consultation component is analyzed applying this framework. Results indicate little discrimination between the terms engagement, consultation, and participation; however, a range of tactics supported both collaborative and advocacy approaches. The implications for adopting a relational framework for community engagement programs are discussed.

Experimental investigation of a turbulent reacting plume

An experimental investigation has been made of a round, non-buoyant plume of nitric oxide, NO, in a turbulent grid flow of ozone, 03, using the Turbulent Smog Chamber at the University of Sydney. The measurements have been made at a resolution not previously reported in the literature. The reaction is conducted at non-equilibrium so there is significant interaction between turbulent mixing and chemical reaction. The plume has been characterized by a set of constant initial reactant concentration measurements consisting of radial profiles at various axial locations. Whole plume behaviour can thus be characterized and parameters are selected for a second set of fixed physical location measurements where the effects of varying the initial reactant concentrations are investigated. Careful experiment design and specially developed chemilurninescent analysers, which measure fluctuating concentrations of reactive scalars, ensure that spatial and temporal resolutions are adequate to measure the quantities of interest. Conserved scalar theory is used to define a conserved scalar from the measured reactive scalars and to define frozen, equilibrium and reaction dominated cases for the reactive scalars. Reactive scalar means and the mean reaction rate are bounded by frozen and equilibrium limits but this is not always the case for the reactant variances and covariances. The plume reactant statistics are closer to the equilibrium limit than those for the ambient reactant. The covariance term in the mean reaction rate is found to be negative and significant for all measurements made. The Toor closure was found to overestimate the mean reaction rate by 15 to 65%. Gradient model turbulent diffusivities had significant scatter and were not observed to be affected by reaction. The ratio of turbulent diffusivities for the conserved scalar mean and that for the r.m.s. was found to be approximately 1. Estimates of the ratio of the dissipation timescales of around 2 were found downstream. Estimates of the correlation coefficient between the conserved scalar and its dissipation (parallel to the mean flow) were found to be between 0.25 and the significant value of 0.5. Scalar dissipations for non-reactive and reactive scalars were found to be significantly different. Conditional statistics are found to be a useful way of investigating the reactive behaviour of the plume, effectively decoupling the interaction of chemical reaction and turbulent mixing. It is found that conditional reactive scalar means lack significant transverse dependence as has previously been found theoretically by Klimenko (1995). It is also found that conditional variance around the conditional reactive scalar means is relatively small, simplifying the closure for the conditional reaction rate. These properties are important for the Conditional Moment Closure (CMC) model for turbulent reacting flows recently proposed by Klimenko (1990) and Bilger (1993). Preliminary CMC model calculations are carried out for this flow using a simple model for the conditional scalar dissipation. Model predictions and measured conditional reactive scalar means compare favorably. The reaction dominated limit is found to indicate the maximum reactedness of a reactive scalar and is a limiting case of the CMC model. Conventional (unconditional) reactive scalar means obtained from the preliminary CMC predictions using the conserved scalar p.d.f. compare favorably with those found from experiment except where measuring position is relatively far upstream of the stoichiometric distance. Recommendations include applying a full CMC model to the flow and investigations both of the less significant terms in the conditional mean species equation and the small variation of the conditional mean with radius. Forms for the p.d.f.s, in addition to those found from experiments, could be useful for extending the CMC model to reactive flows in the atmosphere.

Modeling multivariate autoregressive conditional heteroskedasticity with the double smooth transition conditional correlation GARCH Model

In this paper, we propose a multivariate GARCH model with a time-varying conditional correlation structure. The new double smooth transition conditional correlation (DSTCC) GARCH model extends the smooth transition conditional correlation (STCC) GARCH model of Silvennoinen and Teräsvirta (2005) by including another variable according to which the correlations change smoothly between states of constant correlations. A Lagrange multiplier test is derived to test the constancy of correlations against the DSTCC-GARCH model, and another one to test for another transition in the STCC-GARCH framework. In addition, other specification tests, with the aim of aiding the model building procedure, are considered. Analytical expressions for the test statistics and the required derivatives are provided. Applying the model to the stock and bond futures data, we discover that the correlation pattern between them has dramatically changed around the turn of the century. The model is also applied to a selection of world stock indices, and we find evidence for an increasing degree of integration in the capital markets.

Defining the public values in airport development decision-making

Residents, businesses, local, state and national government stakeholders all want to have their say when airports expand or develop. While stakeholder engagement is increasingly a strategy employed for managing the tensions attracted to airport development, different stakeholders have different expectations and demands of airports. This requires different approaches to stakeholder engagement. Identifying the public values that are at stake in developing airports provides an initial step towards building a platform for selecting and applying stakeholder engagement strategies in airport and more general infrastructure contexts. -------- This paper uses the existing literature of public values to build a general typology of public values for the stakeholders of airport development. A range of semi-privatised and state owned airport case studies from Europe have been used to demonstrate the universal nature of the identified values. The result is a framework that identifies both the substantive and procedural values, separated into local, state/regional and national levels of interest. The typology provides a generalised view of public values in airport development; however, the public values identified may be limited to more western oriented societies due to the skew of airport cases reviewed. --------- Contributions are made to the literature with a typology of public values derived from existing knowledge and explored using empirical case examples. The provided typology enables research of airport development decision-making to delineate public values both within and between stakeholder groups, and helps to explain the different perspectives that stakeholders have towards airport development. Future research may focus on refining the typology for different types of airport governance structures, such as differences between public values in state and market-led airport development; include more airport cases from eastern societies to draw parallels or differences between western and eastern societies; or utilise the typology as a framework for analysing changes in public values of airports over time.

Cities in the airports 'shadow' : underlying interests and discretionary power in airport-region development

The previously distinct boundary between airports and their cities has become increasingly blurred as new interests and actors are identified as important stakeholders in the decision making process. As a consequence airport entities are more than ever seeking an integrated existence with their surrounding regions. While current planning strategies provide insights on how to improve and leverage land use planning in and around airports, emerging challenges for implementing and protecting these planning ideals stem from the governance shadows of development decisions. The thesis of this paper is that improving the identification, articulation and consideration of city and airport interests in the development approval process (between planning and implementation) can help avoid outcomes that hinder the ability of cities and their airports to meet their separate/mutual long-term objectives. By applying a network governance perspective to the pilot case study of Brisbane, analysis of overlapping and competing actor interests show how different governance arrangements facilitate (or impede) decision making that protects sustainable ‘airport region’ development. ---------- Contributions are made to airport and city development decision makers through the identification and analysis of effective and ineffective decision making pathways, and to governance literature by way of forwarding empirically derived frameworks for showing how actors protect their interests in the ‘crowded decision making domain’ of airport region development. This work was carried out through the Airport Metropolis Research Project under the Australian Research Council’s Linkage Projects funding scheme (LP0775225).