Published Article / Any effort to build up an educational framework needs an adequate structure and a formal basis. This is especially true whenever complex multifaceted issues like Sustainable Development, ethics, or project management have to be integrated in the existing setting of a university and its educational system. In this paper, we present models for integrating Sustainable Development and Education for Sustainable Development into the university agenda. Based on the experience of the authors gained in Germany and South Africa we derive various representations for the sustainability activities and models for implementing Sustainable Development that can be used for planning, implementation and communication purposes.

Published Article / Although deterministic models still dominate hydrological modelling, there is a notable paradigm shift in catchment response modelling. An approach to represent the daily rainfall-flow (R-F) relationship using Data-Based Mechanistic (DBM) modelling is presented. DBM modelling is an inductive empirical transfer function (TF) approach relating input to output. The study used secondary data from the Department of Water Affairs and Forestry for the Upper Vaal water management area at station C1H007. The R-F model identification and optimisation was implemented in the CAPTAIN Toolbox in MATLAB. The best estimated R-F model was a 2nd order TF with an input lag of one day and R 2T= 56%. In mechanistic interpretation, three parallel flow pathways were discerned; the fast flow, slow flow and the loss component each constituting 49.8%, 24% and 26.2% of the modelled flow respectively. The study demonstrates that the approach adopted herein produces reasonably satisfactory results with a minimum of the readily available catchment data.

Published Article / This paper identifies the most significant technological developments made in medical applications of rapid prototyping and manufacturing (RP&M) over the past decade. This assessment is based on a retrospective analysis of the research undertaken by the Medical Applications Group of the National Centre for Product Design and Development Research (PDR), based at the University of Wales lnstitute Cardiff (UWIC). UK. The paper describes the state of technology at the inception of the Group in 1998 and then highlights the significant technological developments that impacted on the activities of the Group over the decade to 2008. The paper will also discuss how these technologies have developed since their initial implementation. The paper will conclude with suggested directions future work should take in order to meet clinical and technical needs.

Published Article / Current fused deposition modelling (FDM) technologies deposit material as flat layers. The result is a "stair-case" effect on non-vertical or horizontal surfaces, and compromised part strength because of weakness between the laminations. This paper describes an FDM method through which layers of build material are deposited as curved layers following the shape of the part, thus removing the stair-case effect and creating parts that have an even strength distribution over their entire surface. Support material is first deposited as conventional flat layers, and build material is then deposited over the support structure following the curves of the part. The paper discusses a proof of concept of the system, the algorithms used to generate the curve paths for the deposition head, and examines the challenges and possibilities of this technology, including the capability of including composite materials.

This work outlines a programme of research tasked with the exploration of representing psychologically grounded theories of emotion through fuzzy logic systems. It presents an introduction to the specific goals of the project, followed by an overview of the wider, multi-disciplinary field of emotion representation. Two emotion theories are explored in detail. One, rooted in behaviourism, proposed by J. R. Millenson in 1967; the other, the Geneva Emotion Wheel proposed by K. R. Scherer in 2005. Each of these theories is independently abstracted mathematically, and represented in terms of both type-1 and type-2 fuzzy logic systems. Six potential implementations of these systems are presented. Of these, five are tested within this report. The results of these tests are analysed and discussed in the context of both computational behaviour and psychological analogue. There follows a critical review where the effectiveness of the different implementations and models is considered, informed by both testing results and the psychology upon which they are based. A prototype of one implementation applied to govern the behaviour of an agent in a predator-prey scenario is included. Discussion of this prototype includes examples of how the implementation was practically applied to the environment, and an assessment of the behaviours of the agent in testing. The work concludes with an overview of the thesis, including discussion of the results of the project and future avenues of research related to the completed work. The contributions of the thesis are explicitly outlined: the research of pre-existing, psychologically grounded models of emotional state suitable for computational representation; construction of mathematical representations of two models of emotion, using both type-1 and type-2 fuzzy logic; and, the presentation of five computational implementations of those representations, of which four are explicitly tested, compared and critically reviewed.

This thesis presents three dynamic stochastic general equilibrium models to answer three macroeconomic questions. In each model, I impose one or more frictions or constraints and analyse how these frictions affect macroeconomic dynamics. Chapter 2 studies the coordination of fiscal and monetary policies under optimal commitment and discretion policies under a New Keynesian framework. The chapter shows that when there is indexation in price setting which depends on the lagged output gap as in Steinsson (2003), under the optimal commitment policy, both fiscal and monetary policies have active roles in inflation stabilisation, even although debt follows a unit-root process. Under the optimal discretion policy, both fiscal and monetary policies have active roles in inflation stabilisation to drive debt back to the pre-shock level, consistent with Leith and Wren-Lewis (2008). Extending the model to include capital accumulation does not alter these results. Chapter 3 presents a microfounded two-country model of global imbalances and debt deleveraging. During global imbalances a sustained rise in saving in one country can lead to a worldwide fall in the interest rates and an accumulation of debt in the other country. When an ensuing deleveraging shock occurs as a result of the global financial crisis, the interest rates are forced further down. I show that in the presence of a liquidity trap the deleveraging country may face a combination of a large fall in output, deflation and real exchange rate appreciation, as a result of debt deflation. Chapter 4 adds a highly-leveraged financial sector to the Ramsey model and shows that this augments the macroeconomic effects of aggregate productivity shocks. My model is built on the financial-accelerator approach of Bernanke, Gertler and Gilchrist (BGG), in which leveraged goods-producers borrow from a competitive financial sector. In this chapter, by contrast, financial institutions are leveraged and subject to idiosyncratic productivity shocks. They obtain funds by paying an interest rate above the risk free rate, and this risk premium is anti-cyclical, and so amplifies the shocks. My parameterisation, based on US data, is one in which the leverage of the financial sector is two and a half times that of the goods-producers in the BGG model. This causes a much more significant augmentation of aggregate productivity shocks than that found in the BGG model.

Anthropogenic noise in the sea is now classed as a pollutant alongside chemical pollution and marine litter in accordance with the Marine Strategy Framework Directive. Noise from shipping is a major contributor to the ambient noise levels in the ocean, particularly at low (<300Hz) frequencies. The properties of sound propagation in shallow waters are highly influenced by the marine physical environment. Ocean modelling plays an important role in underwater noise studies since it can provide high resolution water column parameters over large geographic areas. This study investigates the noise patterns and their temporal variations in the Celtic Sea by using a coupled ocean model (POLCOMS) and an acoustic model (HARCAM). A method to predict noise exposure experienced by marine animals is then developed, following an application for diving seals. The ocean model is applied in the Celtic Sea to provide high-resolution 3D hourly temperature and salinity fields for the acoustic model. The model is validated against in-situ and satellite observations, giving high skills to simulate the water column structures. Sensitivity studies of modelled results to different atmospheric forcing are carried out in order to improve the accuracy of the model. The results show that the modelled sea surface temperature, stratification and water column structures are highly sensitive to the choice of surface forcing, especially in the summer time. The increase in resolution of surface forcing does not necessarily lead to more accurate results. The tidally frontal position is, however, insensitive to the forcing. The variability of noise propagation is studied using the coupled model, demonstrating high dependence on oceanographic conditions, geographic location of sound source and its depth. In summer, when the source of sound is on the inshore side of the bottom front, the sound energy is mostly concentrated in the near-bottom layer. In winter, the sound from the same source is distributed more evenly in the vertical. When the source is on the seaward side of the front, the sound level from a shallow source is nearly uniform in the vertical and the transmission loss is significantly greater (~16dB at 40km distance) in summer than in winter. In contrast, sound energy from a deep source is trapped in the bottom cold water, leading to a much lower transmission loss (~20dB) in summer than in winter. Note that ~10dB fluctuation of sound energy is found during the deterioration of the thermocline in late autumn. Shallow sources (e.g. ships) are sensitive to the surface heat flux as it changes significantly the vertical temperature gradient, while tides play an important role in determining the TL variability of deeper sources (e.g. pile driving) since they cause adjustments of positions of subsurface fronts. The seasonal noise patterns radiated by a large cargo ship are modelled by relating the AIS ship track data and the coupled model, showing a clear influence of the seasonal thermocline and associated bottom fronts on shipping noise distribution. The noise propagates much further (tens of kilometres) in winter than in summer. The predicted shipping noise exposure perceived by grey seals shows strong step changes in the sound level during their descent/ascent through the water column. Since grey seals tend to be benthic foragers, a hypothesis that the step change in sound exposure may have negative impacts on their foraging behaviour is proposed for biological specialists.

There is a growing body of literature reporting the application of hybrid simulations to inform decision making. However, guidance for the design of such models, where the output depends upon more than one modelling paradigm, is limited. The benefits of realising this guidance include facilitating efficiencies in the general modelling process and reduction in project risk (both across measures of time, cost and quality). Focussing on the least well researched modelling combination of agent-based simulation with system dynamics, a combination potentially suited to modelling complex adaptive systems, the research contribution presented here looks to address this shortfall. Within a modelling process, conceptual modelling is linked to model specification via the design transition. Using standards for systems engineering to formally define this transition, a critical review of the published literature reveals that it is frequently documented. However, coverage is inconsistent and consequently it is difficult to draw general conclusions and establish best practice. Therefore, methods for extracting this information, whilst covering a diverse range of application domains, are investigated. A general framework is proposed to consistently represent the content of conceptual models; characterising the key elements of the content and interfaces between them. Integrating this content in an architectural design, design classes are then defined. Building on this analysis, a decision process is introduced that can be used to determine the utility of these design classes. This research is benchmarked against reported design studies considering system dynamics and discrete-event simulation and demonstrated in a case study where each design archetype is implemented. Finally, the potential for future research to extend this guidance to other modelling combinations is discussed.

Drag reduction in wall-bounded flows can be achieved by the passive flow control technique using riblets and surface grooves aligned in the mean direction of an overlying turbulent flow. They were inspired by the skin of fast sharks covered with small longitudinal ribs on their skin surfaces. Although it was found that the drag reduction depends on the riblets’ geometrical characteristics, their physical mechanisms have not yet been fully understood in the scientific terms. Regarding riblets sizing, it has been critically explained in the literature how riblets with vanishing size interact with the turbulent flow and produce a change in the drag proportional to their size. Their shapes are focused upon because these are most significant from a technological perspective, and also less well understood. Different riblet shapes have been designed, some with complicated geometries, but except for the simple ones, such as U and V grooves, there has not been enough study regarding shape features. Therefore, special effort is undertaken to the design of an innovative type of ribleted surface, e.g. the Serrate-Semi-Circular shape, and its effect on the skin friction and drag reduction. In this work, the possible physical mechanisms of riblets for turbulent drag reduction have been explored. The modelling and experiments concerning the relationship between the riblets features and the turbulent boundary layer structure have also been reviewed. Moreover, numerical simulations on riblets with different shapes and sizes are presented and studied in detail. An accurate treatment based on k-ε turbulence model was adopted to investigate the flow alteration and the consequent drag reduction on ribleted surfaces. The interaction of the overlying turbulent flow with riblets and its impact on their drag reduction properties are further investigated. In addition, the experimental facilities, instrumentation (e.g. hotwires) and measurement techniques (e.g. time-averaged turbulence structure) have been employed to experimentally investigate the boundary layer velocity profiles and skin friction for smooth and micro-structured surfaces (the proposed riblet shape, respectively and the presented new design of riblets with serration inside provides 7% drag reduction. The results do not show significant reduction in momentum transfer near the surface by riblets, in particular, around the outer region of the turbulent boundary layer. Conclusions with respect to the holistic investigation on the drag reduction with Serrate-Semi-Circular riblets have been drawn based on the research objectives as achieved. Recommendations for future work have been put forward particularly for further future research in the research area.

This thesis documents research providing improvements in the field of accessibility modelling, which will be of particular interest as computing becomes increasingly ubiquitous. It is argued that a new approach is required that takes into account the dynamic relationship between users, their technology (both hardware and software) and any additional Assistive Technologies (ATs) that may be required. In addition, the approach must find a balance between fidelity and transportability. A theoretical framework has been developed that is able to represent both users and technology in symmetrical (hierarchical) recursive profiles, using a vocabulary that moves from device-specific to device-agnostic capabilities. The research has resulted in the development of a single unified solution that is able to functionally assess the accessibility of interactions through the use of pattern matching between graph-based profiles. A self-efficacy study was also conducted, which identified the inability of older people to provide the data necessary to drive a system based on the framework. Subsequently, the ethical considerations surrounding the use of automated data collection agents were discussed and a mechanism for representing contextual information was also included. Finally, real user data was collected and processed using a practically implemented prototype to provide an evaluation of the approach. The thesis represents a contribution through its ability to both: (1) accommodate the collection of data from a wide variety of sources, and (2) support accessibility assessments at varying levels of abstraction in order to identify if/where assistance may be necessary. The resulting approach has contributed to a work-package of the Sus-IT project, under the New Dynamics of Ageing (NDA) programme of research in the UK. It has also been presented to a W3C Research and Development Working Group symposium on User Modelling for Accessibility (UM4A). Finally, dissemination has been taken forward through its inclusion as an invited paper presented during a subsequent parallel session within the 8th International Conference on Universal Access in Human-Computer Interaction.