• Canada
• UK Research and Innovation close
• UKRI|EPSRC close
• 2011 close

I aim to develop high level structures for reasoning about knowledge of agents in a multi-agent system where agents communicate and as a result update their information. All of us take part in such situations when communicating through the internet, surfing the web, bidding in auctions, or buying on financial markets. Reasoning about knowledge acquisition in these situations becomes more challenging when some agents are not honest and they cheat and lie in their actions and as a result other agents acquire wrong information. The current models of these situations are low level: they require specifying untidy details and hide the high level structure of information flow between the agents. This makes modeling a hard task and proving properties of the model an involved and complicated problem. The complexity of reasoning in these situations raises the question: ``Which structures are required to reason about knowledge acquisition?'', in other words, ``What are the foundational structures of knowledge acquisition?''. High level methods provide us with a minimal unifying structure that benefits from partiality of information: we do not need to specify all the details of the situations we are modeling. They also bring out the conceptual structure of information and update, hide the untidy details, and tidy up the proofs. My plan is to (1) Study the foundational structures that govern knowledge acquisition as a result of information flow between the agents and then develop a unifying framework to formally express these structures in a logical syntax with a comprehensive semantics. I aim to use known mathematical structures, such as algebra, coalegbra and topology, for the semantics. The syntactic theory will be a rule-based proof-theoretic calculus that helps us prove properties about knowledge acquisition in a programmatic algorithmic manner. (2) Apply this framework to reason about security properties of multi-agent protocols. Examples of these protocols are communication protocols between a client and a bank for online banking. We want to make sure that such a protocol is secure, that is, the client's information remains secret throughout the transaction. Because of the potentially unlimited computational abilities of the intruder, these protocols become very complex and verifying their security becomes a challenging task. It is exactly here that our high level setting becomes a necessity, that is, in formal analysis of these protocols and in proving their security properties. The semantic structures that I aim to use have also been used to model the logic of Quantum Mechanics. So my model will be flexible enough to accommodate quantum situations. These situations are important for security protocols because they benefit from additional non-local capabilities of Quantum Mechanics, which guarantee better safety properties. I aim to apply the knowledge acquisition framework to Quantum protocols and prove their sharing and secrecy properties. On the same track, similar semantic structures have been used for information retrieval from the web. I aim to exploit these models and study their relationship to my framework. (3) Write a computer program to implement the axiomatic semantic structure and produce a software package. This software will help us automatically verify properties of multi-agent protocols, such as the security protocols mentioned above.

As more slender and more adventurous structures, such as cable-stayed bridges, are constructed, they become increasingly susceptible to large amplitude vibrations, particularly due to aerodynamic loading. Wind-induced vibrations of bridge decks, cables, towers, lamp columns and overhead electricity cables are indeed very common. This can lead to unacceptably large movements, direct structural failure, or dangerous long-term fatigue damage of structural components. Complex interactions between the wind and the structure and also between different components of the structure (e.g. cables and bridge deck) can lead to vibration problems, so for proper understanding of the behaviour, both aerodynamic and structural effects need to be considered.Whilst some of the mechanisms of wind loading of structures are reasonably well understood, others are not, and many instances of vibrations, particularly of cables, are not well explained. Recent work has developed a generalised method for analysing 'galloping' vibrations. These are caused by changes in wind forces on a structure when it starts to move, which actually tend to increase the motion. For typical bridge cables (or other similar size structures) in moderately strong winds, a particular change in the wind flow around the cable occurs, known as the drag crisis. This changes the forces on the cable and causes a special case of galloping-type vibrations, which the new method of analysis is able to predict, for the first time. Comparisons of these calculations with wind tunnel test results on inclined cylinders have confirmed that the basic method does work, but there is a need to consider additional effects, such as wind turbulence, torsional motion of the structure and more accurate account of the changes in the aerodynamic forces as the structure moves. It is proposed to develop the approach to include these effects, using further wind tunnel data, to eventually create a unified framework for wind loading analysis of any real structure for galloping, together with the other aerodynamic mechanisms buffeting (due to wind turbulence) and flutter.Meanwhile, interactions between vibrations of structural components can cause serious effects. For example, very small vibrations of a bridge deck can cause very large vibrations of the cables supporting it, through the mechanism of 'parametric excitation'. Even more surprisingly, in other instances, localised cable vibrations can lead to vibrations of the whole structure. Research under another grant is already considering these effects for very simplified structures, but it is proposed to extend the analysis to realistic full structures. Also, often cables are tied together to try to prevent vibrations of individual cables, but they can then all vibrate together as a network. This project therefore aims to analyse full cable networks, to understand how their vibrations can be limited.Finally, it is proposed to bring together the above two main areas, to include both aerodynamic and structural dynamic interactions in the analysis of slender structures. For example, because of the interactions, the wind loads on relatively small elements, such as cables, can have surprisingly large effects on the overall dynamic response of large structures. At present this is generally ignored, but the joint approach will address this issue. Also, in some instances, only a combined view of the phenomena may be able to explain the behaviour observed on full-scale structures in practice. The holistic view of the wind loading and structural behaviour should provide tools to help avoid undesirable and potentially dangerous effects of vibrations of slender structures in the future. Based on the analysis, this could be achieved by modifying the shape of the elements to change the wind loads, or introducing dampers to absorb enough vibration energy.

The aim of Silicon photonics is nothing less than the complete convergence of optics and electronics. In the first instance this endeaviour was aimed at oversoming the limitations imposed by nature in the transport of information using electrons. However, the work has already thrown up more general optical technologies which can be minaturised onto silicon chips. In fact, engineers are slowly building a whole optics toolbox on silicon, including detectors, modulators and spectrometers. The international consortium assembled for the current work have already made significant progress in providing the long sought after on-chip light source. The feasibility studies proposed here are aimed at building on the existing expertise found in the consortium and elsewhere to apply these technologies to the optical detection and manipulation of single biomolecules in a way than can be miniaturised giving devices that have such functionalities on a silicon chip. The impact of the work will be enhanced by the fact that the approaches used are compatible with those used during the manufacture of standard silicon chips and that the end products can be mass produced (at costs measured in cents per unit) for personalised health care applications in every home, doctor's surgery/pharmacist; for the detection of low level atmosphere or water born pollutants or for counter terrorism/military applications

Heavy crude oil and bitumen are a vast, largely unexploited hydrocarbon resource, with barely 1% produced so far, compared with more than 50% of conventional light oil (like the North Sea). More than 80% of this heavy, unconventional oil, lies in the Western hemisphere, whereas more than 80% of conventional light oil lies in the Eastern hemisphere (mainly in the Middle East). Over the next 10-30 years, geopolitical factors,and also the emerging strength of Asian countries, especially India and China, will create increasing tensions and uncertainty, with regard to the availability and supply of crude oil. Alongside gas, nuclear and renewables, crude oil will continue to be an important part of the UK's 'energy mix' for decades to come. How will the crude oil we need for industry and transportation be be obtained and will it be as secure as it was from the North Sea?The huge Athabsca Oil Sands deposits in Canada (1.5 trilllion barrels) provides an opportunity for the UK to secure access to a long-term, stable supply. The first step towards this was the development of a new technology,THAI - 'Toe-to-Heel Air Injection', to produce Oil Sands bitumen and heavy oil. It was discovered by the Improved Oil Recovery group at the University Bath, in the 1990's, and is currently being field tested at Christina Lake, Alberta, Canada. In 1998, in collaboration with the Petroleum Recovery Institute (PRI), Calgary, Canada, the Bath goup discovered another process,based on THAI, called CAPRI. The THAI-CAPRI processes have the potential to convert bitumen and heavy crude into virtually a light crude oil, of almost pararaffin-like consistency, at a fraction of the cost of conventional surface processing. A surface upgrading plant has recently been proposed for the UK, at a cost of $2-3 billion.The advantage of CAPRI is that it creates a catalytic reactor in the petroleum reservoir, by 'sleeving' a layer of of catalyst around the 500-100 m long horizontal production well, inside the reservoir. The high pressure and temperature in the reservoir enable thermal cracking and hydroconversion reactions to take place, so that only light, converted oil is produced at the surface. Apart from the cost of the catalyst, which can be a standard refinery catalyst, the CAPRI reactor is virtually free! All that is needed is to inject compressed air, in order to propagate a combustion front in a 'toe-to-heel' manner along the horizontal production well.In collaboration with the University of Birmingham, the project will investigate the effectiveness of a range of catalysts for use in the CAPRI process. The University of Birmingham team, led by Dr. Joe Wood, wiil investigate the long-term survivability of the catalysts,which is critical for the operation of CAPRI. Once the catalyst is emplaced around the horizontal well, it will be expensive to recover or replace it. Previous 3D combustion cell experiments conducted by the Bath team, only allowed catalyst operating periods of a few hours, whereas, in practise, the catalyst will need to survive, remain active, for days, or weeks. The Bath team will undertake detailed studies to characterise the internal pore structure of the catalysts used in the experiments, to obtain fundamental information on catalyst deactivation, which can be related to the process conditions and oil composition. They will also develop a detailed numerical model of the CAPRI reactor. This will provide a tool to explore 'fine details' of the THAI-CAPRI process, which will aid in the selection/optimisation of the most suitable catalysts. The model will be incorporated into a larger model using the STARS reservoir simulator. Preliminary reservoir siumlations will be made to explore the potential operating conditions for CAPRI at field -scale.On a commercial-scale, the THAI-CAPRI process could translate the oil resource in the Athabasca Oil Sands into the world's biggest, exceeding the Middle East.

Aerosols are important in a wide range of scientific disciplines, from the delivery of drugs to the lungs, to their impact on the earth's climate and their role in climate change, through to their application in the delivery of fuels for combustion, and their processing in plasmas to prepare functionalised materials. Defined as a dispersion of solid or liquid particles within the gas phase, aerosol properties are governed by the chemical composition and size of the individual particles. It is also widely recognised that the chemical composition of the surface of a particle can play a critical role in governing the properties of the aerosol. This is primarily because aerosols can present a large surface area to the surrounding gas phase. Any chemistry that occurs must be mediated through transfer of molecules from the gas phase into the bulk of the particle across the surface. The chemical make-up of the surface can significantly influence this transfer. Further, it is recognised that particles are generally not uniform in composition throughout their volume. For example, a single particle may consist of organic and water phases that are not mixed, but are phase separated. This can have a profound influence on the properties of a particle when compared with the properties expected for a particle characterised by uniform mixing.In this research we will investigate the relationship between the chemical, physical and optical properties of aerosol particles and their chemical composition and uniformity in composition. We will develop new techniques to examine the internal structure within a single particle, to explore how different chemicals mix or separate in a single particle, and to investigate the ease with which molecules are taken up at the surface of the particle. In addition, we will develop a new instrument to measure how efficiently a particle absorbs light. In the atmosphere, aerosol particles can scatter sunlight back into space, counteracting the heat trapping properties of the greenhouse gases. However, some pollutant particles, such as black carbon produced in combustion, strongly absorb sunlight enhancing the warming of the atmosphere. The impact of aerosols remains poorly quantified and new techniques are required to study their light absorption properties.The novel experiments described above are based around two new powerful techniques. Using a tightly focussed laser beam, we can hold onto a single particle indefinitely. Known as optical tweezers, this approach has been widely used for holding particles in liquids. However, we have shown that the same approach can be used to hold onto aerosol particles. Further, light can become trapped in spherical aerosol droplets in much the same way as light undergoes total internal reflection in the formation of a rainbow. The light can travel a distance of metres around the edge of the droplet before escaping. By measuring the wavelength of the light, we can determine how far the light must travel to make one complete circuit of the droplet circumference. Not only can this provide a very accurate way of determining the size of the droplet, but it can enable us to make sensitive measurements of the composition of the droplet near the droplet surface. It is anticipated that the development and application of these new techniques will yield important new information on the properties of aerosols and their behaviour in many of the complex scientific problems highlighted above.

Since the development of the first Kerr-lens mode-locked lasers in 1990, practical femtosecond lasers in a wide variety of configurations have delivered handsomely to a significant number of major scientific developments. It has to be recognised that the application space remains limited by the cost, complexity, skilled-user requirements and restricted flexibility of the current generation of ultrafast lasers. In this proposed joint project we seek to lead the way in the development of a new generation of ultrafast lasers. By adopting a modular approach for laser design we are aiming to demonstrate a platform from which lasers can be designed to address a wide range of user-specific requirements. By taking this approach, lasers for use in communications, for example, will have the necessary high repetition rates and low peak powers whereas for biophotonics high peak powers will be delivered to take full advantage of exploitable optical nonlinearities. We plan to work with vibronic crystals in both bulk and waveguide geometries and semiconductor quantum dot structures as the primary gain media. Although vibronic crystals have been deployed widely in ultrashort-pulse lasers the flexibility offered by conventional laser designs is very limited. To remedy this situation we intend to revolutionise cavity design to enable electrical control of the laser output parameters. For example, we wish to provide a means to users to change from an unmodelocked status to a femtosecond-pulse regime on demand. Also, by exploiting waveguiding in vibronic crystals we are confident that we can introduce a new generation of highly compact lasers that will combine many of the advantages of a semiconductor laser with the most attractive features of crystal based devices. In some preliminary work in the Ultrafast Photonics Collaboration we have shown the potential of semiconductor quantum dot structures as broadband gain media that can support the amplification and generation of femtosecond optical pulses. We now seek to build on those promising results and move towards truly flexible ultrafast lasers that will be amenable to external electronic control of the gain and loss components. Progress is expected to lead to a new generation of lasers that can give applications compatibility that far exceeds available traditional laser system designs. Within this strategy we plan to employ hybrid approaches where the benefits of semiconductor lasers will be combined with the energy storage capabilities of crystals to deliver compact and rugged sources having pulse characteristics that cover a range of durations, energies and profiles.A major part of this project effort will be devoted to the development of control functionality in ultrafast lasers. The intention is to use direct electrical control of intracavity components to deliver designer options for pulse shaping, modulated data streams, wavelength tuning and tailored dispersion. To ensure that this research is applicable we will evaluate the laser developments in the context of a set of identified demonstrators. These implementations will be used to show how design flexibility can deliver optimised lasers for biological, medical, communications and related applications.We have put together a research team having complementary of expertise and established track records of international excellence in photonics. This project as a whole will be managed from St Andrews University but all three research groups will undertake interactive research on all aspects of the laser development. We are confident that the work of this team will represent cutting-edge fundamental and translational research and it should represent a world leading strength for the UK in the development of new ultrafast lasers.

In this project we propose to investigate techniques that will allow an additional human sense, haptic touch (or reflected force), to be sent over the Internet. Today's telecommunications and computer networks have been designed to carry information that pertains to only two human senses: the auditory sense (for example sound and speech), and the visual sense (for example video, graphic, and text etc). The Internet is now being reengineered so that it can provide different levels of service for different types of traffic, e.g. to support the transport of voice over its IP protocol (VOIP). This has lead to the design of network architectures that can support different Quality of Service (QoS) levels. It is clear that introducing into networks the ability to carry information relating to other senses will open up an enormous potential for both new and dramatically improved applications. The ability to embed touch or force into applications and then distribute them across the Internet will have significant implications in areas such as collaborative design, immersive reality and teleconferencing, distance learning and training, virtual reality showrooms and museums. It is now also recognised that the introduction of a haptic component to interactive games has increased users' quality of experience, and this has in turn increased the market demand for these types of applications. It is also clear that the network service (i.e. QoS) needed to support other senses such as touch (haptics) will be significantly different from that which currently exists.Almost all haptic applications are designed whereby the haptic device is connected to a single stand-alone system, or where dedicated connections are used to provide remote interaction. Architecting the Internet to provide an acceptable service for distributed haptic applications therefore represents a significant challenge that this research aims to address. A related challenge is to design architectures that can scale to support the QoS required for the interaction of multiple haptic devices (or users).Recent research has shown that each type of network impairment affects the sense of force feedback in a particular way. Network delay can make the user feel a virtual object before it is visually in contact, or to move into solid objects. Delay also desynchronizes the different copies of the virtual environment. Jitter makes the user feel that the object's mass is variable. Packet loss can reduce the amount the force felt by the user. The effect of these impairments is to introduce unwanted artefacts into the virtual environment. However they also effect the interaction with the physical world and a more serious consequence is to cause damage to the haptic device, and in some situations may also cause physical damage to the end user. To date, the network has not been seriously considered in the design of haptic compensation algorithms. However the introduction of graded QoS architectures (e.g. Diffserv) into the next generation Internet now offers the capability to bound effects such as packet delay jitter and loss. These guarantees can be used to offer specific levels of tolerance (spatial and haptic) to different applications. Therefore a major contribution of the research will be to develop compensation techniques that consider the current level of service that the network can offer and map these against different types of haptic applications.A series of trials investigating the performance of the derived architectures and compensation algorithms will be conducted with the collaborators who represent key constituents in this technology area: BT (network operator, UK), LABEIN (haptic applications, Spain), HandshakeVR (haptics software, Canada), and Immersion (haptic device manufacturer, California). The results will provide valuable knowledge to the designers of future devices, DHVEs and to the designers of the networks that have to support them.

The ability to control the evolution of a reaction is a long-standing goal of chemistry. One approach is to use the electric field provided by a laser pulse as the guide. Recent work has focused on shaping and timing the pulse so that the field interacts with the molecules in a particular way to influence the energy flow through the molecule and thus eventually the course of a reaction. The optimal pulse shape is achieved by using a feedback loop , focusing on a signal related to the desired outcome and allowing a computer algorithm to change the pulse shape during repeated cycles of the experiment until the signal is maximised. This optimal control scheme has proved to be able to control a wide range of chemical systems, but the complicated pulse shapes provide little insight into the procedure, and the experiments have a black box nature. A different, very appealing, approach to control through a laser field is to use the field to change the shape of the potential energy surface over which the reaction proceeds. This can be acheived using a strong pulse which induces Stark shifting of the surface. By careful timing of a pulse of the appropriate strength, it has been shown that it is possible to control the products from IBr dissociation by effectively changing the barrier height to the different possible channels.The project aims to investigate theoretically this potentially general approach to laser control. The results should start to build up a picture of how the complicated potential energy surfaces of small molecules are altered by interaction with the field. This will help in the development of experiments and in our understanding of how molecules behave in a light field.

Software systems are rarely written from scratch: they evolve over long periods of time. When a change is made, this often affects many different locations in a system, and it is hard to make a change consistently. For that reason, automated tools to help the process of software change are desirable. Refactoring refers to the process of restructuring an existing piece of software, often prior to introducing new functionality, or to take advantage of a new technology. Refactoring must preserve the behaviour of existing code;,and tools that help in refactoring both assist in the restructuring process and in checking that the behaviour has not changed. Unfortunately today's refactoring tools are very hard to construct, they are still quite limited in functionality, and they often contain bugs.This project aims to construct a framework for better refactoring tools. In particular, the work is driven by refactorings for a new set of language features, called `aspect-oriented programming' that have recently been added to Java.Our framework will be based on developments in three separate areas of computer science:* `strategies' to control the process of rewriting program code, from the `term rewriting' community* `reference attribute grammars' to specify the conditions that guarantee behaviour is preserved, from the `compilers' community* `incremental evaluation' of declarative rules, from the `functional and logic programming' communityThe quality of our framework will be assessed by coding selected case studies using alternative methods. In particular, we shall implement several refactorings directly in Eclipse, the leading development environment for writing aspect-oriented programs in industry.

In this proposal, we seek Follow-on funding to support the technical and commercial development of a cheap highly portable terahertz (THz) frequency time-domain spectrometer that will, within a five year timescale, reduce both the cost and size of such instrumentation by a factor of >10. The IP which we will exploit is the generation and detection of terahertz radiation from a new material (iron-doped indium gallium arsenide, Fe-InGaAs) which is showing tremendous potential for integration with relatively cheap telecoms wavelength lasers, which we developed using a recent EPSRC grant (PORTRAIT; EP/D50225X/1). We have protected use of this material for THz spectroscopy by a recent GB patent application (GB 0912512.1), and now seek to commercialize our results in order to push the wide-scale uptake of THz spectroscopy systems across a broad range of application areas, which include (but are not restricted to) the pharmaceutical, security, process monitoring, and medical sectors. In each area, there have been extensive demonstrations (by both academia and industrial R&D laboratories) of the potential impact of THz spectroscopy, but the keys factors of price and lack of portability have so far limited commercial uptake. Our new material allows efficient THz emission using cheap and highly portable (1.55 micron) fibre lasers. We have shown that it is possible to construct fibre-coupled THz emitters and detectors using our material which offer greater flexibility and enhanced performance compared to existing technology. We now seek to create optimized prototype THz emitters and detector components, based on our recently patented new material, which will be appropriate for widespread applications of THz frequency range sensing across many sectors.Terahertz time-domain spectroscopy (THz-TDS) systems have wide-scale applicability, especially for the measurement of polycrystalline powders, which typically have characteristic fingerprint spectra in the THz frequency range. THz spectroscopy and imaging systems thus offer the possibility of non-contact characterization and monitoring of a wide range of materials, which include pharmaceutical drugs, drugs-of-abuse, and explosives, inter alia. We are targeting the pharmaceutical market during the Follow-on funding period, owing to the established use of THz technology there. THz-TDS is proven to have importance in the pharmaceutical industry owing to its ability to distinguish polymorphic forms, and the ability to penetrate tablet coatings and packaging. Furthermore, it provides complementary information to other vibrational spectroscopic techniques, particularly Raman spectroscopy, owing to the different selection rules governing which normal modes are observed. The US Food and Drug Administration guidance for pharmaceutical development, manufacturing, and quality assurance has explicitly placed process analytical technologies, such as THz-TDS, as central to innovation in pharmaceutical manufacture over the coming decade.