• Canada
• 2012-2021close
• UK Research and Innovation close
• UKRI|EPSRC close
• 2011 close

Connectedness, as in "can we get there from here", is a fundamental concept, both in actual space and in various abstract spaces. Consider a long ladder in a right-angled corridor: can it get round the corner? Calling it a corridor implies that it is connected in actual three-dimensional space. But if we consider the space of configurations of the ladder, this is determined by the position and orientation of the ladder, and the `corridor' is now the requirement that no part of the ladder run into the walls - it is not sufficient that the ends of the ladder be clear of the walls. If the ladder is too long, it may have two feasible positions, one in each arm of the corridor, but there may be no possible way to get from one to the other. In this case we say that the configuration space of the ladder is not connected: we can't get the ladder there from here, even though we can get each end (taken separately, which is physically impossible) from here to there. Connectedness in configuration space is therefore the key to motion planning. These are problems human beings (especially furniture movers, or people trying to park cars in confined spaces) solve intuitively, but find very hard to explain. Note that the ladder is rigid and three-dimensional, hence its position is determined by the coordinates of three points on it, so configuration space is nine-dimensional. Connectedness in mathematical spaces is also important. The square root of 4 can be either 2 or -2: we have to decide which. Similarly, the square root of 9 can be 3 or -3. But, if 4 is connected to 9 in our problem space (whatever that is), we can't make these choices independently: our choice has to be consistent along the path from 4 to 9. When it is impossible to make such decisions totally consistently, we have what mathematicians call a `branch cut' - the classic example being the International Date Line, because it is impossible to assign `day' consistently round a globe. In previous work, we have shown that several mathematical paradoxes reduce to connectedness questions in an appropriate space divided by the relevant branch cuts. This is an area of mathematics which is notoriously difficult to get right by hand, and mathematicians, and software packages, often have internal inconsistencies when it comes to branch cuts. The standard computational approach to connectedness, which has been suggested in motion planning since the early 1980s, is via a technique called cylindrical algebraic decomposition. This has historically been computed via a "bottom-up" approach: we first analyse one direction, say the x-axis, decomposing it into all the critical points and intermediate regions necessary, then we take each (x,y)-cylinder above each critical point or region, and decompose it, then each (x,y,z) above each of these regions, and so on. Not only does this sound tedious, but it is inevitably tedious - the investigators and others have shown that the problem is extremely difficult (doubly exponential in the number of dimensions). Much of the time, notably in motion planning, we are not actually interested in the lower-dimensional components, since they would correspond to a motion with no degrees of freedom, rather like tightrope-walking. Recent Canadian developments have shown an alternative way of computing such decompositions via so-called triangular decompositions, and a 2010 paper (Moreno Maza in Canada + Davenport) has shown that the highest-dimensional components of a triangular decomposition can be computed in singly-exponential time. This therefore opens up the prospect, which we propose to investigate, of computing the highest-dimensional components of a cylindrical decomposition in singly-exponential time, which would be a major breakthrough in computational geometry.

Imperfectly observed evolving systems arise throughout the human world. Weather forecasting, modelling stock prices, transcribing music or interpreting human speech automatically are just a few of the situations in which imperfect observations of a system which evolves in time are all that is available whilst the underlying system is the thing in which we are interested: Given satellite observations and sparse localised measurements, we'd like to accurately characterise the weather now and predict future weather; given measurements of pitch at discrete times we'd like a computer to be able to produce a meaningful description of what was being said at the time.Surprisingly, it's possible to model a great number of these problems using a common framework, known as a state space model (or hidden Markov model). Inferring the likely value of the unobserved process based upon a sequence of observations, as those observations become available is in principle reasonably straightforward but it requires the evaluation of integrals which cannot be solved by analytical mathematics and which are too complex to deal with accurately via simple numerical methods. Simulation-based techniques have been developed to address these problems and are now the most powerful collection of tools for estimating the current state of the unobserved process given all of the observations received so far. Much effort has been dedicated in recent years to designing algorithms to efficiently describe the likely path of the unobserved process from the beginning of the observation sequence up to the current time in a similar way. This problem is much harder as each observation we receive tells us a little more about the likely history of the process and continually updating this ever-longer list of locations in an efficient way is far from simple.The methods proposed here will attempt to extend simulation-based statistical techniques in a new direction which is particularly well suited to characterisation of the whole path of the unobserved process and not just its terminal value. Two different strategies based around the same premise - that sometimes several smaller simulations can in a particular sense outperform a single larger simulation for the same computational cost - will be investigated. The techniques developed will be investigated both theoretically and empirically.In addition to developing and analysing new computational techniques, the project will provide software libraries which simplify the use of these methods in real problems (hopefully to the extent that scientists who are expert in particular application domains will be able to apply the techniques directly to their own problems).The research could be considered successful if:1/ It leads to new methods for performing inference in state space models.2/ These methods can be implemented with less application-specific tuning that existing methods require or these methods provide more efficient use of computational resources.3/ These methods are sufficiently powerful to allow the use of more complex models than are currently practical.4/ The methods are adopted by practitioners in at least some of the many areas in which these techniques might be usefully employed.The long term benefits could include more realistic assessment of risk in financial systems, more reliable tracking and prediction of meteorological phenomena and improved technological products wherever there is a need to dynamically incorporate knowledge arising from measurements as they become available. There will be particular advantages in settings in which the full path of the imperfectly observed underlying process is of interest but there is scope for improvement even when this is not the case.

Underinvestment in Manufacturing in the UK over the past decade has left this vital pillar of the economy exposed. OECD statistics show this starkly when comparing the UK to competitors whose sectors have grown since the start of the new millennium - the UK has- The largest proportion of low technology companies - The lowest proportion of employees in manufacturing- The lowest R & D spend as a function of GDP- The highest wage costs when compared to productivity.The recent economic crisis has highlighted the UK's over dependence on the financial services sector. Countries such as France and Germany with larger and growing manufacturing bases both emerged from the global recession more rapidly than the UK. This gap in support for the manufacturing sector has been recognised by EPSRC who made provisions to stimulate new IMRCs and doctorate training centres which can support UK manufacturing through close collaboration with the science base at universities.MATTER is a new initiative at Swansea specifically targeted at high technology advanced manufacturing and exploits the considerable experience of running industry facing doctorate centres at Swansea University. MATTER will be run in the multidisciplinary research environment provided in the School of Engineering at Swansea spanning all three research centres - computational, materials and nanotechnology. It will be led by a team of highly experienced researchers representing a wide range of expertise across the centres. Swansea has been a pioneer of the EngD concept since its inception in 1992. The award winning research and training partnerships continue with two highly focused doctoral training partnerships for the steel industry in Wales and for structural metallic systems for gas turbines. Swansea is also the lead organisation on the ERDF funded project ASTUTE to support Advanced Sustainable Manufacturing Technologies in Wales with postdoctoral research and extensive knowledge transfer activities from academia to industry. Manufacturing also strongly features in the HEFCW funded project to establish ArROW, an Aerospace Research Organisation Wales, which is led by Swansea University. The latter is to build research capacity, but it lacks funds for the critical element of doctoral students to more extensively engage with industry.In analysing technical roadmapping documents from the packaging and the aerospace industries, and the portfolio of support offered to manufacturing industries, Swansea University has identified key gaps and opportunities to work with the supply chains in Packaging, Automotive and Aerospace specifically outside of the EU convergence areas covered by existing funding. Within these technology clusters are key cross cutting themes, lean principles, sustainability, and value added. The gap in support will be filled through the generation of an advanced manufacturing centre that will train a minimum of 26 engineering doctorate research engineers, adding value to the training schemes already in place to service the Welsh convergence regions. MATTER will concentrate on increasing the intellectual value of the products and processes in order to add value through innovation, decreasing the commodity element of much of the UK sector. A key area of focus for MATTER will be improving processes to minimise waste and to improve quality.The existing infrastructure at Swansea University will underpin MATTER maximising the number of students that can be trained. Swansea will contribute 56% of the fees along with the provision of training costs and administration support from within their extensive infrastructure build up around several large scale projects, such as STRIP, ASTUTE and ArROW. Industry will also make a considerable additional contribution both in terms of in kind support and cash. The combined contribution from industry and Swansea University to MATTER will provide approximately 2 for every 1 requested from EPSRC.

Current computer graphics techniques allow us to render almost any object at near photo-realistic quality. However, the standard approach necessitates that the user painstakingly specifies all aspects of the geometric and material properties of the object. This is time-consuming and needs skilled human operators. It is hard to edit the resulting models at anything other than the low level of geometry and materials at which they are specified. Moreover, we cannot edit real photographs without reverse engineering the underlying model and this is very difficult.In this proposal we investigate a radically different pipeline for computer graphics that will allow non-experts to rapidly create and edit photo-realistic two dimensional images of objects. The crux of our approach is to provide the computer with a deeper understanding of the class of objects under consideration. This knowledge (which takes the form of a statistical model) is then leveraged to help the user achieve their goals more easily. The impact of this project is potentially enormous. Such a technology could become a standard tool installed on every home and business computer. Some of the many potential applications are:- Conceptual design. Manufacturing industries often need to sketch new product ideas and refine existing designs. Our system could help a fashion designer produce and manipulate photo-realistic images of new garments.- Clipart objects. Stock images are required for on-line and real-world publishing and these are often sought via search engines (e.g. Google Images). However, the returned results are often not ideal and may be subject to copyright. Our approach will allow the user to design bespoke images to exactly their specifications.- Photo and movie editing. Digital editing of images and movies is commonplace, but requires considerable skill. Our techniques could be used to modify facial expressions in portrait photography or apply digital cosmetics in movie post-production.- Content for virtual worlds. The trend towards larger 'sandbox' environments in video games has created an explosive demand for graphical content. Our system could allow automated or semi-automated creation of photorealistic building facades for a large virtual environment.

In the UK there are more than four billion square metres of roofs and facades forming the building envelope. Most of this could potentially be used for harvesting solar energy and yet it covers less than 1.8 % of the UK land area. The shared vision for SPECIFIC is develop affordable large area solar collectors which can replace standard roofs and generate over one third of the UK's total target renewable energy by 2020 (10.8 GW peak and 19 TWh) reducing CO2 output by 6 million tonnes per year. This will be achieved with an annual production of 20 million m2 by 2020 equating to less than 0.5% of the available roof and wall area. SPECIFIC will realise this by quickly developing practical functional coated materials on metals and glass that can be manufactured by industry in large volumes to produce, store and release energy at point of use. These products will be suitable for fitting on both new and existing buildings which is important since 50% of the UKs current CO2 emissions come from the built environment.The key focus for SPECIFIC will be to accelerate the commercialisation of IP, knowledge and expertise held between the University partners (Swansea, ICL, Bath, Glyndwr, and Bangor) and UK based industry in three key areas of electricity generation from solar energy (photovoltaics), heat generation (solar thermal) and storage/controlled release. The combination of functionality will be achieved through applying functional coatings to metal and glass surfaces. Critical to this success is the active involvement in the Centre of the steel giant Corus/Tata and the glass manufacturer Pilkington. These two materials dominate the facings of the building stock and are surfaces which can be engineered. In addition major chemical companies (BASF and Akzo Nobel as two examples) and specialist suppliers to the emerging PV industry (e.g. Dyesol) are involved in the project giving it both academic depth and industrial relevance. To maximise open innovation colleagues from industry will be based SPECIFIC some permanently and some part time. SPECIFIC Technologists will also have secondments to partner University and Industry research and development facilities.SPECIFIC will combine three thriving research groups at Swansea with an equipment armoury of some 3.9m into one shared facility. SPECIFIC has also been supported with an equipment grant of 1.2 million from the Welsh Assembly Government. This will be used to build a dedicated modular roll to roll coating facility with a variety of coating and curing functions which can be used to scale up and trial successful technology at the pre-industrial scale. This facility will be run and operated by three experienced line technicians on secondment from industry. The modular coating line compliments equipment at Glyndwr for scaling up conducting oxide deposition, at CPi for barrier film development and at Pilkington for continuous application of materials to float glass giving the grouping unrivalled capability in functional coating. SPECIFIC is a unique business opportunity bridging a technology gap, delivering affordable novel macro-scale micro-generation, making a major contribution to UK renewable energy targets and creating a new export opportunity for off grid power in the developing world. It will ultimately generate thousands high technology jobs within a green manufacturing sector, creating a sustainable international centre of excellence in functional coatings where multi-sector applications are developed for next generation manufacturing.

This project focuses on energy and more specifically on nuclear fission. Core material such as fuel assemblies are exposed to irradiation from the moment a nuclear reactor is switched on. The bombardment of material with neutrons creates collision cascades that immediately produce point defects and dislocations in the material. This results in very significant changes of the material properties compared to non-irradiated material.Nuclear fuel for light water reactors is contained by so-called cladding tubes, which are made from zirconium alloys because of their excellent corrosion resistance, sufficient mechanical properties and their low neutron absorption coefficient. Nuclear fuel is enriched initially with 5% 235U. However, the fuel cannot be fully burned due to the uncertainty of clad material degradation and dimensional instability of fuel assemblies. The dimensional instabilities are related to irradiation growth and creep of zirconium alloys. Irradiation growth occurs in zirconium alloys without applying any external load and is due to the hexagonal close packed crystal structure of zirconium. Irradiation creep is significantly faster than thermal creep due to the increased density of vacancies in irradiated material. The safe operation of nuclear fuel assemblies requires dimensional stability to ensure sufficient coolant flow and the safe operation of control rods when needed. Irradiation growth and creep can lead to bowing and buckling of fuel assemblies, which is of concern with current plants and even more a concern for increased burnup of the nuclear fuel. Consequently, we need to develop a detailed understanding of the mechanisms leading to these phenomena and how they are affected by material chemistry and the microstructure evolution during irradiation.Traditionally, microstructure and damage characterisation of irradiated material is mainly carried out by electron microscopy. However, in the last decade, very powerful 3rd generation synchrotron radiation sources have been built, which represent a tremendous opportunity to develop complementary tools or quantitative characterisation of irradiation damage and microstructure evolution.During the 1960s and 70s many countries including the UK had test reactors that allowed scientists to undertake research on irradiated material. However, most of these test reactors are gone now and it is unlikely that the UK or other countries will build many new test reactors. For this reason, governments have invested in proton/ion accelerators to simulate neutron irradiation. The advantage of such facilities is that they are by many order of magnitudes cheaper to run than a test reactor. However, our understanding of how well neutron induced damage is related to proton/ion induced damage is limited. Since Zr alloys are relatively mildly active when irradiated by neutrons, they represent also an ideal material to calibrate proton/ion against neutron irradiation.During the fellowship my research group will:- identify the role of alloy chemistry and microstructure on irradiation growth and creep of fuel clad,- for the first time extensively use synchrotron radiation to characterise irradiation damage and- calibrate proton/ion irradiated against neutron irradiated cladding material in order to use the convenience of the former (non-active material, easily irradiated to different levels in a short time) to identify the route cause for loop formation resulting in breakaway growth