Research topics
PhD and MSc R research topics
Title: Approximation algorithms in phylogenetics
Supervisor: Dr Magnus Bordewich
Description: Many problems in phylogenetics, bioinformatics and beyond cannot be solved exactly in polynomial time. This project will look at the development and use of approximation algorithms to solve such problems. Possible specific topics include approximating the SPR distance between two phylogenetic trees and the related problem of approximating the minimum hybridisation number of two trees. The work will include theoretical analysis of the performance of algorithms, the development of new algorithmic approaches and could include empirical testing of competing algorithms on real and simulated data sets.
Title: Distance based methods in phylogenetic reconstruction
Supervisor: Dr Magnus Bordewich
Description: One approach to phylogenetic reconstruction is to compute a matrix of pair-wise distances between species, e.g. based on the difference in their DNA sequences, and try to find a phylogenetic tree that most closely fits this estimated distance matrix. Whist not regarded as as accurate as likelihood or parsimony based methods, distance based methods are very fast and efficient. This project would
involve: the theoretical analysis of distance based algorithms, e.g.
FastME and balanced minimum evolution based methods, to give stronger accuracy guarantees; the design of new distance based algorithms for phylogenetic reconstruction; and it could include empirical comparison of the performance of different methods.
Title: Mixing times in Markov Chain Monte Carlo sampling
Supervisor: Dr Magnus Bordewich
Description: Markov Chain Monte Carlo sampling (MCMC) is a widely used technique to sample from hard to compute distributions. MCMC involves simulating a Markov chain that converges to the distribution of interest until it is close enough to its stationary distribution for an accurate sample to be taken. The difficulty lies in knowing how long one must wait to be close to stationarity - the mixing time of the Markov chain. This theoretical project will analyse Markov chains from combinatorics and statistical physics to bound their mixing times. For example, typical Markov chains could be associated with proper colourings of graphs or the ferromagnetic Potts model. The project will require skills in probability and in combinatorics.
Title: Complexity gap for resolution
Supervisor: Dr Stefan Dantchev
Description: The project will study the resolution proofs of first-order expressible propositional contradictions. These formulae are highly uniform and one could safely conjecture that their complexity in weak proof systems (such as resolution) satisfies a dichotomy theorem. That is, these tautologies naturally split into two: the easy ones, which have small (polynomial size) proofs, and the hard ones, which require very big (fully exponential size) proofs. The investigation will build upon some existing complexity gap results, e.g. the ones for tree-like resolution and relativised first-order sentences in resolution. Expected outcomes are either a proof of the full complexity gap theorem for resolution or partial results contributing to the characterisation of both the hard and the easy cases
Title: Pebble games and complexity of structured pigeon-hole principle
Supervisor: Dr Stefan Dantchev
Description: The aim of this project is to study links between pebble games from finite model theory and complexity of proving non-isomorphism between two relational structures in weak propositional proof systems. (the latter is known as structured pigeon-hole principle (PHP)).
It is fairly intuitive that if the spoiler can win a game with bounded number of pebbles, the respective structured PHP is easy to prove. The main task will be to prove the complementary
direction: if the duplicator can force usage of unbounded number of pebbles in a game then one can extract a lowerbound proof from his strategy. The investigation will focus on studying different proof systems (resolution, cutting planes, polynomial calculus etc.) and finding the right parameter (the one that corresponds to the number of
pebbles) for each of them
Title: Cryptographic hash functions based on expander graphs
Supervisor: Dr Stefan Dantchev
Description: This project involves designing and studying hash functions based on walks in expander graphs. The main theoretical task is to construct a family of expanders that are explicit and for which the problem of finding short cycles is provably computationally hard. The investigation will build upon the existing expander constructions - there are quite a few but is not straightforward to find one that is both simple enough (so that a practical implementation will be efficient) and provably collision-resistant (i.e. one can prove that finding a short cycle is hard modulo some complexity-theoretic assumptions). The project also has a significant practical component, which involves an implementation and a practical evaluation of the proposed hash function(s)
Title: Balls-into-bins games
Supervisor: Dr Tom Friedetzky
Description: Balls-into-bins games are probablistic processes whereby "balls"(think computer tasks) are randomly allocated to "bins" (thinkprocessors). Balls-into-bins games may be used to e.g. model real-world load balancing problems in computer networks. The objective, in general, is to mathematically analyse the resulting load distributions, or to investigate the long-term behaviour in case of dynamic systems. Many "simple" models are well understood. There are, however, many challenging "specialised" sub-models left (assuming e.g. non-uniform balls or bins, or balls with dependent choices) that still await thorough, formal analysis
Title: Diffusion-based load balancing
Supervisor: Dr Tom Friedetzky
Description: Diffusion load balancing is a theoretical model which allows one to design and analyse certain kinds of network-based load balancing problems. It is a strictly local approach in that nodes will exchange load only with direct neighbours. The questions asked are diverse; one may be interested in the time it takes diffusion to evenly spread a fixed amount of load among all nodes, or in the long term behaviour of systems where new load is continually being generated
Title: Augmented random walks
Supervisor: Dr Tom Friedetzky
Description: A random walk on a graph is a simple recipe: if you are on any node of the graph, then where do you go next? Usually, one picks one of the neighbours of the current walk uniformly at random. Recently there has been research into "augmented walks" where these decisions may, in some way or another, depend on the current local neighbourhood or other properties of the past behaviour. Typical questions being asked are, e.g., how long does it take, in expecation, until all nodes of the graph have been visited, or how long does it take until the probability for the walk to be on any given node has "stabilised"?
Title: Graph augmentation
Supervisor: Dr Matthew Johnson
Description: Many variants of the following problem can be considered: given a directed or undirected graph and a measure of connectivity, what is the fewest number of edges that can be added to obtain a graph with a prescribed value of that measure. The proposed project would study the computational complexity of these and related problems.
Title: Complexity of reconfiguration problems
Supervisor: Dr Matthew Johnson
Description: A reconfiguration problem asks for a "path" between two solutions of a problem. For example, given two truth assignments that satisfy a boolean formula, can a set of intermediate assignments be found that link them with "adjacent" assignments differing in the value of just one variable; or given two proper colourings of a graph, can they linked by a set of colourings such that adjacent colourings differ in the colour of only one vertex. There are many open problems: for example, do all problems in P correspond naturally to polynomially solvable reconfiguration problems?; characterise the complexity of specific reconfiguration problems --- the Travelling Salesman Problem is one example where this is open?; there are many NP-complete problems known to give rise to PSPACE-complete reconfiguration problems: can approximation algorithms be found?
Title: Colour graphs
Supervisor: Dr Matthew Johnson
Description: The k-colourings of a graph form the vertex set of its k-colour graph; vertices are joined by edge if the colourings differ on a single vertex. When k is more than 3, little is known about k-colour graphs: what is the complexity of deciding whether one is connected?; what is a tight bound on the diameter of its components?; is there a threshold beyond which a random graph of degree d(k) will have a connected colour graph? The proposed project would seek to answer some of these questions.
Title: Exact algorithms for NP-hard problems
Supervisor: Dr Daniel Paulusma
Description: There is a growing number of practical problems within the area of algorithmic graph theory that are NP-hard. Since P=NP seems very unlikely, exact algorithms that have exponential running time may be the best algorithms for obtaining optimal solutions for NP-hard problems. This project aims are to construct and improve exact algorithms for a number of specific graph-theoretic problems and to show how exact algorithms for different problems are related to each other.
Title: Algorithmic aspects of graph colouring
Supervisor: Dr Daniel Paulusma
Description: Graph colouring involves the labelling of the vertices of some given graph by a minimum number of integers called colours such that no two adjacent vertices receive the same colour. This project addresses the following questions. What is the computational complexity of a particular colouring problem? For which graph classes and variants is it polynomially solvable and for which is it NP-hard? If the problem is NP-hard, can one find good upper bounds and/or approximation algorithms for the minimum number of colours?
Title: Computational complexity in cooperative game theory
Supervisor: Dr Daniel Paulusma
Description: One of the central problems in cooperative game theory is to distribute the total profits or costs among the players of a cooperative game. For doing this many methods called solution concepts have been designed. The choice for a specific solution concept S depends on the notion of fairness specified within the decision model and its computational complexity. These two factors can be conflicting, and this project aims are to determine the computational complexity of a number of solution concepts for various cooperative games and to design alternative solution concepts for those ones that are NP-hard.
Title: Microfluidic systems for THz biological analysis
Supervisor: Dr Andrew Gallant
Description: The terahertz region sits between the infrared and microwave sections of the electromagnetic spectrum. In recent years, terahertz radiation has been used for the characterisation of chemical and biological material. However, these studies have been dominated by dry samples due to the high attenuation of THz in water. The thin films of water found in microfluidic systems make them ideal delivery systems for wet terahertz studies. This project will involve the design, fabrication and testing of microfluidic system for biological cell sorting and positioning, with the aim of delivering the sample under test directly to the THz beam
Title: Fully integrated THz source/detector systems
Supervisor: Dr Andrew Gallant
Description: The aim of this project is to design, fabricate and test fully integrated THz source/detector systems. These systems will form part of a microfluidic system for the high throughput characterisation of 'wet' biological material. The terahertz region sits between infrared and microwave in the electromagnetic spectrum. It is a comparatively underexplored region due to a shortage of efficient sources and detectors. Source and detector optimisation will form an important aspect of this project and is likely to include the use of artificially engineered materials
Title: Rectifying antennas and circuits for microwave power transmission
Supervisor: Dr Andrew Gallant
Description: A receiver for microwave power would include antennae and rectification to DC (rectennas). This project will build on past work with metamaterials and rectennas for shorter wavelengths (infra red) to develop high efficiency rectennas for use in the microwave band. Various configurations (dielectric resonator) and rectifying circuits (Schottky diode) will be explored and work is also planned on novel high-frequency circuit coupling methods and the use of new low-loss semiconductor devices to produce higher efficiency microwave circuits
Title: Exploring the morphology-performance relationship in organic photovoltaics
Supervisor: Dr Chris Groves and Dr Nigel Clarke (Dept of Chemistry)
Description: The price of solar energy is prohibitive to its widespread use, however, organic materials offer the chance to dramatically reduce this cost below that which is capable using standard inorganic technology. Organic photovoltaics are made from mixtures of two polymers or small molecules in order to form a transporting network for the electrons and holes. How this transporting network is arranged can make dramatic differences to how efficiently the solar cell operates. In this project we combine sophisticated charge transport simulations with realistic descriptions of how the transport networks are arranged (working in collaboration with Nigel Clarke of the School of Chemistry), allowing us, for the first time, to link physical properties of the polymer with the performance of the organic photovoltaic. This is an area of high interest in a diverse and exciting research area, and will give many opportunities to publish papers in high ranked journals
Title: Exploring the limits of organic photovoltaic performance
Supervisor: Dr Chris Groves
Description: Organic photovoltaics may prove a new paradigm in how renewable energy is generated as they can significantly reduce the cost of solar energy. Much work is at present being expended to understand the physics and chemistry of how these devices operate, however, one area that is underdeveloped is the investigation of how engineering issues limit the performance, and conversely how module design can improve performance. This project is involved with exploring the practical limits of what performance can be achieved in a large-area, mass-produced solar cell. Additionally, we will address how photovoltaic module design, specifically light absorption strategies, can be utilized in a large-area device
Title: Organic materials as optical sensors
Supervisor: Dr Chris Groves
Description: Organic materials have a number of advantages when it comes to use as an optical sensor. First, their absorption strength is incredibly high, meaning efficient absorption can require as little as 100nm or material. Second, the absorption wavelength can be tune widely through changes in the chemical structure. Despite these advantages, the application of organic materials as optical sensors, in applications ranging from medical imaging, to military sensing, to consumer electronics, has received little attention. In this project we will work with colleagues in Sheffield University to fully characterize the detector properties of organic devices for the first time. As a new area of science, there is also significant opportunity to develop the underpinning science and theory of such devices, and in turn give rise to high-impact research
Title: White-light organic light emitting devices
Supervisor: Professor Mike Petty
Description: Electroluminescence in organic materials is now the subject of intense worldwide research. Over the past ten years significant progress has been made with the development of organic light emitting devices (OLEDs). Devices emitting colours across the entire visible spectrum and operating at low drive voltages, high efficiencies and with long lifetimes are now available. If the rate of progress can be sustained into the next decade, OLED technology has the potential to have an impact on general lighting applications. In particular, a large-area white-light-emitting OLED could provide a solid state diffuse light source that might complete with conventional lighting technologies
Title: Organic solar cells
Supervisor: Professor Mike Petty
Description: Concerns over global climate change, local air pollution and resource depletion are making photovoltaics (PVs) an increasingly attractive method of energy supply. The current technology, based on single crystal silicon, is more expensive than conventional power generation and there is much research on alternative materials. Photovoltaics using organic compounds, such as polymers or dyes, offer the possibility of large scale manufacture at low temperature coupled with low cost. This project will investigate the fabrication and characterisation of organic PV devices
Title: Plastic transistors and memories
Supervisor: Professor Mike Petty
Description: The evolution of silicon microelectronics, the major enabling technology of the information revolution is threatened not only by technical issues that may restrict the further miniaturization of integrated circuits, but also from the increased fabrication cost that accompanies shrinking the feature size below 100 nm. To overcome these limitations, a worldwide research effort aiming at devices that go beyond conventional device architectures is underway. Memories represent by far the largest part of electronic systems and there is a very strong driving force to develop novel memory architectures. The purpose is to find materials and concepts that lead to devices that are scalable for at least several generations below 50 nm and fast (ns and less). In parallel, there is an upsurge in interest in plastic electronics, i.e. transistors and other devices based on polymeric or low molecular weight organic semiconductors. Such low-cost devices will not compete directly with single crystal silicon in terms of operation speed but are likely to form key components in display drivers in portable computers and pagers, and as components in transaction cards and identification tags
Title: Nanoelectronics using carbon nanotubes
Supervisor: Professor Mike Petty
Description: Carbon nanotubes are comprised of graphite-like sheets curled into a cylinder. Because of their very small diameters (down to around 0.7 nm), carbon nanotubes are prototype one-dimensional nanostructures. The electronic structure of a nanotube is either metallic or semiconducting, depending on its diameter and chirality. This project will explore methods to make thin molecular architectures incorporating carbon nanotubes (for example, inkjet printing and layer-by-layer electrostatic deposition) and to measure their electrical conductivity. The application of the thin film assemblies to electronic devices, such as chemical sensors or switches will be explored
Title: Holographic lithography
Supervisor: Professor Alan Purvis
Description: Conventional silicon chip making uses 2D masks to make 2D circuits on a silicon wafer. We have found that it is possible to use holographic masks to make 3D computer chips. This project will involve pioneering some of the opportunities this new fabrication tool permits. For example 3D wireless antennas can be integrated into a complex Signal processing package to enable distributed parallel computing. The project requires an interest in optical systems, the ability to programme computers and an commitment to work with Industry
Title: Self healing computers
Supervisor: Professor Alan Purvis
Description: We are all familiar with the biological process of self repair. When damage or malfunction occurs the bio-system directs resources as far as it is able to restore normal function. Some species and tissues are more able to do this than others and by studying how he bio-solution works we hope to gain and insight into making self healing computer systems. An everyday example would be built in self test and fix memory. All memory chips risk bit failure though recent strategies mitigate catastrophic defects and manufacture and during the memory chips lifetime. We aim to use mathematical stem cell arrays to reorder circuit components to fix malfunctioning systems. The project requires and interest in Electronics and Mathematics and a practical approach to solving problems
Title: Super GPS telemetry
Supervisor: Professor Alan Purvis
Description: Satellite navigation is now common place and available at low cost to everyone. Linking these satnavs to mobile phones goes one step further in allowing tracking to occur. A further step is to uplink the SatNav to the Satellite comms network and allow upbiquitous tracking. However, all of these systems operate with a very slow time onstant of order minutes. The aim of this project is to enhance trackability to permit real time robotic guidance over the web. Updates on position every second is the target with intelligent control of the Unmanned System using environmental feedback in addition to positional information alone. Hardware and Software programming skills in Electronics is required together with an interest in communications and/or robotics
Title: Double directional channel modelling
Supervisor: Professor Sana Salous
Description: The project involves performing measurements with the multiple input multiple output channel sounder in the radio systems group using different frequency bands. The measurements will be used to develop angle of arrival and angle of departure information of the different multipath components to investigate the parametric channel model
Title: Rural broadband
Supervisor: Professor Sana Salous
Description: The provision of broadband to rural areas is currently provided by satellite links. An alternative is to provide wireless links using the ISM bands at 5.8 GHz and 2.4 GHz. The aim of this project is to perform measurements in the rural areas around Durham and to investigate the coverage and quality of service that Wi-Fi and Wi-Man can provide
Title: Wideband channel simulator
Supervisor: Professor Sana Salous
Description: A channel simulator based on the frequency transfer function has been developed in the radio systems group. The simulator in its present form using Simulink. The purpose of this project is to design a suitable architecture that can be implemented in hardware using digital signal processing techniques
Title: Ultra wideband channel measurements
Supervisor: Professor Sana Salous
Description: UWB has been proposed as a possible solution to in house and short-range communication. The purpose of the project is to design and implement a suitable antenna array and to perform measurements in suitable environments for the assessment of the feasibility of such technology
Title: Ad hoc networks
Supervisor: Professor Sana Salous
Description: Ad hoc networks are expected to provide connectivity through relaying packets between different users. Power control and range issues as well the possibility of the application of MIMO to such networks are to be investigated in this project
Title: Renewable energy in smart clothes
Supervisor: Professor David Wood
Description: Portable electronics are now permanent features of everyday life. Battery function and lifetime, while always improving, is still a problem. If renewable energy sources could be woven into the fabric of clothing then it is then only a small step before the batteries are eliminated entirely. This requires an appreciation of what type of power source is needed if the ultimate end product is a piece of clothing. In this project the emphasis will be on photovoltaic cells that are; fabricated on flexible substrates, durable, efficient and cost-effective
Title: Integrated components for mobile phones
Supervisor: Professor David Wood
Description: Further advances in phone technology will require greater functionality in a smaller space. For the ‘front end' of a phone, a frequency agile filter circuit will require the integration of inductor-capacitor elements on one substrate. In partnership with an IC manufacturer, Filtronic, we have demonstrated the components' principle to a world-leading standard. The challenge is now the integration and test of filter circuits to compete with the discrete circuit approach now being used
Title: Wireless testing of integrated circuits
Supervisor: Professor David Wood
Description: After decades of little change, the testing of integrated circuits is now undergoing rapid evolution. Higher levels of integration, smaller chip sizes, low contact force and plastic electronics all demand a different approach. We have shown a new way of meeting all these challenges using microengineered springs, cantilevers and bridges, and this is currently being exploited by a major chip manufacturer. There may be further opportunities for an even more adventurous, non-contact, approach using wireless technologies. Even within wireless, there are several options, and this project will choose the one most likely to meet the future needs of the IC industry
Title: Contribution of marine energy to demand security
Supervisor: Professor Janusz Bialek and Dr Chris Dent
Description: Great Britain has one of the best wave and tidal energy resources in the world. This project will explore marine energy's contribution to securing peak demand. In the case of wave energy, this will require exploration of the statistical relationship between the wave resource and the level of electricity demand, and construction of an appropriate wave resource model for use in risk calculations. As the tidal resource is determined by the orbits of the sun and moon, any statistical relationship with demand level is expected to be weak, and hence the aim will be to develop a probabilistic resource model. The benefits of diversity arising from generation sites where the tidal cycles are out of phase will also be explored
Title: Risk aversion in the Great Britain wholesale electricity market
Supervisor: Professor Janusz Bialek and Dr Chris Dent
Description: Data analysis performed at Durham suggests that participants in the GB forward electricity market exhibit risk aversion in their trading positions. As they do not have perfect foresight of the real-time demand which they must meet, they on average err on the side of contracting to over-supply their demand, rather than under-supply. This is believed to be because of the greater volatility of the penalty paid in real time for having under-contracted, as compared to that for having over-contracted. This project will examine how this behaviour comes about. The first phase will be a detailed statistical analysis of historic price data, with the aim of determining the circumstances under which risk-aversion is seen. The knowledge gained will then be used to model generating companies' trading strategies, particularly those of wind generators which have very limited control over their outputs in real time
Title: Bluff body aerodynamic unsteadiness relevant to road vehicles
Supervisor: Dr David Sims-Williams and Dr Rob Dominy
Most road vehicles are bluff bodies and are prone to self-excited aerodynamic unsteadiness. Small scale aerodynamic unsteadiness may be manifest as aerodynamic noise while larger scales can potentially have handling implications, particularly for future lightweight vehicles. Durham in a world leader in bluff body unsteady flows and this project would seek to extend the limits of current understanding through flow-field measurements in Durham's 2m wind tunnel. The work would be likely to include a combination of time-resolved pressure probe measurements, hot-wire measurements and particle image velocimetry (PIV) using Durham's 3D stereoscopic PIV system
Title: Landing gear noise source investigations
Supervisor: Dr David Sims-Williams and Dr Rob Dominy
A significant proportion of aircraft noise during landing approach is caused by the airflow over the landing gear. The aerodynamic drag of exposed wheels is often seen as an advantage during the landing phase as it helps to decelerate the aircraft however, this results in aerodynamic unsteadiness which translates to aerodynamic noise. This project would capitalise on Durham's expertise with bluff body aerodynamics and unsteady flow measurement to better understand the unsteady flow, its links to aerodynamic noise
Title: Wind tunnel simulation of atmospheric turbulence and impacts of atmospheric turbulence on wind turbines, MAVs and road vehicles
Supervisor: Dr David Sims-Williams and Dr Rob Dominy
Description: Turbulence in the atmospheric boundary layer has both time-averaged and unsteady effects on wind turbines, micro aerial vehicles (MAVs) and road vehicles. However, the large time and length scales associated with atmospheric turbulence make it a challenge to simulate either in the wind tunnel or with CFD. This project could include work to better characterise atmospheric turbulence, particularly at very low altitudes, work to simulate atmospheric turbulence in the wind tunnel using an active system and the assessment of the impact of atmospheric turbulence in a number of applications
Title:The development of MEMS airflow sensors and actuators
Supervisor: Dr David Sims-Williams and Professor David Wood
Description: Micro Electro-Mechanical Systems (MEMS) provide the opportunity to manufacture very small scale airflow sensors and actuators. This could make it possible to manipulate eddies within a turbulent boundary layer. This could be employed on an aircraft wing either to increase turbulence and delay separation for take-off and landing and to decrease skin friction at cruise. This project could include both the development of MEMS devices and the evaluation of possibilities for turbulence manipulation using Durham's wind tunnel facilities
Supervisor: Katerina Fragaki
Description: The aim of this project is to develop methodologies and tools which will identify whether groups of houses in towns/villages, could form shared communities, for renewable energy applications. A community could include a single house or varying numbers of houses of the same or different types. The energy flows will be simulated and a methodology to specify the dependence of the community to the grid for energy supply will be developed.
The study will be based on previous work on simulation of community energy use and will focus on specific simulation issues. The simulation of building/community small and micro renewable energy generation technologies such as CHP, solar thermal, heat pumps and photovoltaics (PV) will be investigated in detail. A key issue in this research is the diversity of both load and generation. The main focus is to investigate how the aggregation effect may lead to the improved matching of supply and demand.
Some knowledge of programming will be needed.
Supervisor: Katerina Fragaki
Description: Photovoltaic (PV) modules can be incorporated into non-building structures. Examples include the ‘solar electric sunflowers’ and the ‘solar sail’ http://www.iea-pvps.org/products/download/rep7_02.pdf, both of which represent an elegant combination of art and technology. Due to the pressing need for climate change mitigation, the use of PV in non-building structures is a growing research market. This project will aim to develop modular non-building PV structures. The modularity will allow for modification of the size and form to match the specific application. Therefore such structures could potentially be adapted to various urban or semi urban environments and installed as grid-connected PV at the same time as being aesthetically pleasing. A range of existing PV technologies will be investigated. The generated energy will be simulated and further work will identify load profiles to match this type of generation. The work will lead to the development of a methodology for selecting suitable applications of such structures, taking into account both spatial/social issues and technical engineering.
The project will be suitable for a civil engineering or physics graduate.
Supervisor: Katerina Fragaki
Description: It is well known that the wind environment is very important for the estimation of the energy yield from wind turbines. Furthermore, it determines the type of turbines that are more suitable for specific applications.
Available techniques for the estimation of wind environment may include wind velocity and direction measurements at a site, wind speed databases, satellite data, CFD, rules of thumb, and, if available, comparison with met office data. The aim of this study is to investigate the state of the art of these techniques and evaluate their suitability for specific applications in rural and semi-rural areas. The level of accuracy required for generation/demand matching predictions will be investigated. The project will conclude to specific guidelines for applications as a function of the site, type of turbine and load.
The project will be suitable for a candidate with background in physics, mathematics or engineering with some knowledge on statistics and data analysis.
Title: Ultra high performance blade aerodynamics
Supervisor: Dr Grant Ingram
Description: A number of methods have been tested in Durham recently to improve the performance of high pressure turbine blades. Some of these such as profiled endwalls have made significant contributions to real engines such as the Trent 900 on the A380. This project is to examine how these different methods can be combined to improve the flow through high performance blades. 3d geometries will be simulated using modern computer based techniques to calculate the flow around the blades. At the same time tests will be conducted in a wind tunnel. The information obtained from both activities will be used to further our understanding of the benefits and limitations of modern computer based tools. This project would suit an engineering graduate with a strong interest in experimental work and an understanding of design
Title: Urban wind turbine aerodynamics
Supervisor: Dr Grant Ingram
Description: There has recently been much interest in using small wind turbines in the Urban environment to supplement large scale generation. This approach has the advantage that the source of demand is close to supply but has many barriers to adoption, such as noise, safety and unpredictable power output. This project examines the contribution that modern aerodynamics can bring to this problem area. Key areas where modern aerodynamic theory, tools and techniques can play a role are in the assessment of the wind regime in urban environments and how this relates to the average wind speed for a given location, the noise implications of mounting wind turbines in urban locations and the aerodynamic optimisation of wind turbines for the urban environment. This project would be suitable for an engineering or physics graduate with a keen interest in modelling and the importance of sustainability
Title: The exploitation of power system thermal properties for increased penetration of distributed generation
Supervisor:Professor Phil Taylor
Description: This project seeks to exploit the true thermal capacity of power system plant by developing sophisticated thermal models and integrating them into real time active network management systems
Title: Internet services for the next generation of energy services companies
Supervisor: Professor Phil Taylor
Description: This project seeks to develop internet based services for use by energy services companies looking to provide a wide range of energy efficiency, market participation and new and renewable energy management services to domestic, commercial and industrial clients
Title: An investigation of power system voltage control as a demand side management measure
Supervisor: Professor Phil Taylor
Description: Demand side management has yet to take off but is seen as having a crucial role to play in future electricity systems. This project seeks to investigate the degree to which voltage control can be used to modify load demand. This control of load demand could be used to alleviate local network issues or to contribute to global issues such as frequency control
Title: Aerodynamics of vertical axis wind turbines (I)
Supervisor: Dr Rob Dominy
Description: Vertical axis wind turbines (VAWTs) are insensitive to wind direction and are therefore thought to be well suited to operation in turbulent wind. One of their reported disadvantages is that they require a higher wind speed to start than horizontal turbines and therefore provide less power over their lifetime. However, unlike horizontal axis machines they have received little research effort and it is not clear whether the current cut-in speed limitation is a fundamental characteristic or simply a result of under-development. In particular, there is very little reliable information regarding the optimisation of appropriate aerofoil geometries, nor their operation in realistic, turbulent atmospheric conditions. The focus of this particular research project is to investigate the aerodynamic characteristics of vertical axis wind turbines with a particular emphasis upon the transient effects of blade rotation and the effect of atmospheric turbulence on turbine performance. The project will make use of advanced, fast response instrumentation and also the use of CFD modelling to provide further, essential insight into the physics of the flow
Title: Aerodynamic interactions in vertical axis turbine arrays
Supervisor: Dr Rob Dominy
Description: Wind turbines currently offer the most practical source of renewable energy. The largest 'production' turbines stand 130 metres tall but the next generation will reach 175 metres presenting significant planning issues in the UK and elsewhere. There is a strong case for the development of alternative wind farm topographies using smaller but more densely packed turbines. Wind conditions are less favourable closer to the ground and machine efficiency is influenced by the turbine packing density but the availability of large numbers of sites that are unavailable to conventional wind farms might make such turbine arrays attractive. The adoption of vertical axis turbines might offer the potential for tighter packing since their design eliminates the characteristic turbine trailing vortex whilst there is evidence that turbulence can actually enhance their performance. If their potential advantages are to be converted into real benefits we need much greater understanding of the flow physics with particular emphasis on the structure of the wake and the effect of that wake on the performance of adjacent turbines. That will be the focus of this research
Title: Wings in ground effect
Supervisor: Dr Rob Dominy
Description: It is well documented that the lift generated by an aerofoil may be increased significantly when operating in close proximity to the ground. This has considerable potential for extended range and duration of ‘ground effect’ vehicles flying over water where there are far fewer obstacles than for overland operation. Fully operational prototype vehicles have been produced in the past including giant Russian Ekranoplanes. However, the ‘science’ behind WIG (wing in ground effect) is largely based on the assumption that the ground or sea surface is smooth. In reality, flight over water will experience waves and consequently the distance between the wing and the surface constantly changes. Previous research into aerofoil operation performance over wave surfaces has provided some useful but limited steady state information but the crucial effect of the dynamically changing clearance has been completely ignored. The purpose of this research is to investigate those dynamic effects upon aerofoil performance through the design and operation of appropriate wind tunnel techniques and through the use of numerical modelling
Title: Race car wake interaction
Supervisor: Dr Rob Dominy
Description: It is well known that race car aerodynamic downforce is significantly reduced when following another car. Limited wind tunnel studies have been performed using two or more models but to accommodate multiple models within the wind tunnel it is necessary the reduce the model scale which compromises measurement accuracy. It has been proposed that more accurate results could be achieved if the wake from the leading vehicle could be simulated by a dedicated wake generator thus allowing the standard scale test model to be used. Such a device has been tested at Durham University with promising results and the purpose of this research project is to further investigate and develop the wake generation system to evaluate that wake upon the test model’s aerodynamic performance. It is anticipated that the research will require wind tunnel testing, computational simulations and rig design. The project student would be expected to identify the most important parameters for evaluation and to select appropriate research techniques based upon information gained from an appropriate search of the available, relevant literature
Title: Reliability of marine renewable energy devices
Supervisor: Professor Peter Tavner
Description: A large number of wave and tidal devices are under development. The purpose of this project is will be to develop methods to rationalise and evaluate the prospective reliability of these devices in the absence of field data and thereby to determine which architectures are likely to deliver the most reliable and cost-effective energy solutions
Title: Determining the relationship between weather conditions, particularly turbulent wind, and the reliability of wind turbines.
Supervisor: Professor Peter Tavner
Description: Research at Durham has identified a link between weather conditions and location on wind turbine reliability. This linkage needs to be more closely defined in an analytic way so that wind turbine design and operation can be improved to achieve higher reliability, particularly offshore
Title: Improving the reliability of wind turbine drive trains using the brushless doubly fed induction generator
Supervisor: Professor Peter Tavner
Description: The Brushless Doubly Fed Induction Generator has been demonstrated to deliver a more reliable mechanical/electrical energy solution to the variable speed drive wind turbine. This work, which will involve complex electrical machine analysis and experimental work will improve the performance particularly of the rotor of such a machine
Title: Bioengineered lens
Supervisor: Dr Junjie Wu
Description: A 3 year PhD project is available to develop a new bioengineered lens by addressing the structural, biomechanical and biochemical factors in order to offer a revolutionary clinical solution to cataracts and presbyopia. The experimental and numerical novelty of this research challenge lies in both developing the biosubstrates and undertaking advanced simulations of lens deformation. The project is inter-disciplinary and will benefit from our recent successes, as well as the state-of-the-art facilities and expertise available within Schools of Engineering and Computing Sciences, Biological and Biomedical Sciences and Physics at Durham University. The project is ideally suited to enthusiastic good students with a background in either engineering, physics or biology.
Title: Ligament tissue engineering
Supervisor: Dr Junjie Wu
Description: Diseased or damaged tissues as well as tissue degeneration are common to all living organisms. Tissue engineering has the potential to address tissue failure by providing functional biological substitutes grown in vitro that are able to integrate with host tissues and remodel in vivo after implantation. A 3 year PhD project is available to develop reproducible, ready-to-use 3-D bio-scaffolds that can be incorporated into scalable bioprocessing systems suitable for large scale tissue production such as ligaments and tendons for knee joints using the state-of-the-art Knee Simulator in the laboratory. The project is inter-disciplinary and will benefit from the state-of-the-art facilities and expertise available within Schools of Engineering and Computing Sciences and Biological and Biomedical Sciences at Durham University. The project is being undertaken collaboration with University of Oxford and is ideally suited to enthusiastic good students with a background in either engineering, biology or a physical science.
Title: Mobile route planning for cultural explorations
Supervisor: Professor Liz Burd
Description: Project description: Heritage sites are exploring opportunities for visitors to use personal mobile devices in replacement of paper based maps and instructional information. Durham’s TEC project (http://tel1.dur.ac.uk/wiki/doku.php) provides location specific personalised information to mobile users. Since the presentation of information on mobile equipment is dynamic, heritage site have the opportunity to vary information presented to users. For instance, based on visitors specific interests, how busy areas of the site are and specific issues created, for instance, by weather conditions. This research will examine how mobile route planning algorithms can deliver an improved service to heritage visitors using the TEC infrastructure.
This research is suitable for a student with a background in computer science
Title: A distributed multi-touch user interface for music technologists
Supervisor: Professor Liz Burd
Description: The integration of music and film is an important aspect of movie making. This project will explore the user interface of networked multi-touch tables to investigate the design of a new interface to facilitate the collaborative editing of music and video. Specifically the work will concentrate on the human computer interaction design, developing a mechanism where visual manipulation of movie files are collaboratively constructed but where designers do not reside in the same location. The work will therefore construct tools and new interface designs to enable the appropriate editing facilities in shared, but distributed environments.
This research is suitable for a student with a background in music technology or a computer scientist with an interest in music
Title: A study on the impact of orientation on the readability of electronic type-faces
Supervisor: Professor Liz Burd
Description: Table top computing means that computer user interfaces no longer have a specific orientation. Therefore, users are likely to be required to read text that is not in a perfect orientation. This project will investigate the impact on readability of text and how specific type-faces may improve the speed and comprehensibility of text. It will thereby create a new design of a user interface that will seek to appropriate align text to specific users as well as to make recommendations as to the best set of type-faces for such table tops when readability is important.
This research is suitable for a student with a background in educational technologies
Title: Algorithms for multiscopic camera control
Supervisor: Dr Nick Holliman
Description: A key strength of the Durham Visualization Laboratory is binocular imaging, i.e. how to create synthetic and natural binocular images of scenes. A number of successful algorithms for stereoscopic camera control have been developed for static scenes and static cameras, here we look to advance these to manage multiscopic cameras and to account for motion. These algorithms will need to operate in real time and will require look ahead capabilities to predict how the camera parameters should respond to a changing scene. This project requires an ability to understand and mathematically model the complex relationship between purely geometric descriptions of a scene and the human visual system's perception of that geometry. While this is a largely theoretical project there is strong commercial interest in algorithms of this type.
Title: 3D ink
Supervisor: Dr Nick Holliman
Description: The use of 2D painting tools is embedded into everyday computing, almost all document production software packages now allow the use of sketching and drawing using pixel-based graphics. One of the most advanced examples of pixel-based drawing tools is the Adobe Photoshop package. Similar 3D pixel-based drawing packages are rare and have not been widely studied. This project will investigate the algorithms, data structures and HCI systems needed to implement 3D Ink and support pixel-based drawing in 3D, it will build on experience from a number of pilot studies into 3D Ink systems already undertaken in the Durham Visualization Laboratory. It is likely that high performance parallel processing will be required to implement a novel spatial data structure that can support real-time drawing, erasing and rendering of complex 3D sketches. In addition it will be a requirement to use stereoscopic 3D displays to present the 3D sketches to the user and an investigation of the best interaction device to enable natural 3D drawing is an important part of the project.
Title: 3D sound and 3D images
Supervisor: Dr Nick Holliman
Description: Can 3D sound enhance the perception of 3D images? Very little evidence is available about depth perception using sound and even less about the combination of depth from sound with depth from 3D images. This project will thoroughly investigate these issues for 3DTV, 3D Cinema and 3D mobile devices. These investigations will determine whether the limited depth range of 3D displays can be perceptually enhanced by using 3D sound. Algorithms will then be developed to demonstrate how depth perception in 3D visualizations can be modified with the use of appropriate 3D sound.
Title: Artifact-free subdivision surfaces
Supervisor: Dr Ioannis Ivrissimtzis
Description: Description: A subdivision surface is defined by a coarse polygonal mesh which is gradually refined by adding new vertices and connecting them with edges and faces. In the limit of this process we obtain a smooth surface. Subdivision surfaces are simple to implement, numerically stable, topologically robust and support multiresolution representations. They are fast becoming an industrial standard in digital entertainment applications being the format behind Pixar’s popular animation movies. The main drawback of subdivision surfaces is the appearance on the limit surfaces of some unwanted artifacts, such as small spikes and ripples. These artifacts are well-documented in the literature and relatively well understood, however, there is no simple, robust and numerically stable subdivision algorithm suppressing them. This project will propose, implement and evaluate algorithms for artifact-free subdivision surfaces.
Title: Optimal quantisation of 3D polygonal models
Supervisor: Dr Ioannis Ivrissimtzis
Description: Description: Grayscale images are commonly encoded with 8 bits per pixel, while RGB colour images are commonly encoded with 8 bits per pixel per colour band. In contrast, there is no widely accepted common practice regarding the level of quantisation of 3D polygonal models, that is, how many bits per vertex coordinate should be used. While there is evidence that a level of quantisation between 12 and 24 bits per vertex coordinate is sufficient for most applications, nevertheless, most 3D polygonal formats use 32 bits per vertex coordinate. As a result, a significant amount of the information in such formats is redundant. This project will develop the theoretical tools and the practical algorithms for determining optimal levels of quantisation for 3D models, depending on the expected quality of the geometric data and the target application. The aim is to reduce the file size of a typical 3D model and accelerate the geometry processing algorithms by avoiding over-detailed encoding.
Title: Surface reconstruction with overfitting control
Supervisor: Dr Ioannis Ivrissimtzis
Description: Description: Surface reconstruction algorithms create surface representations of scattered point data. In most applications, the input points of the reconstruction algorithm are acquired by optical devices, such as laser scanners, and contain noise. The handling of the data noise is a major technical challenge. For example, several reconstruction algorithms generate surfaces that pass very close to the input points, or even interpolate them. In the presence of noise, this approach is not satisfactory because the reconstructed surface will reproduce the noise in the data. This problem is known in the statistical literature as overfitting. This project will propose, implement and evaluate surface reconstruction algorithms that avoid data overfitting. The algorithms, based on machine learning and statistics, will be able to create surface models that are as faithful to the data as possible while, simultaneously, avoid the reproduction of noise.
Title: Peripheral realism requirements for haptic immersion
Supervisor: Dr Shamus Smith
Description: Building virtual reality applications with high levels of realism is expensive and time consuming. It has been shown that photo-realism is not required for users to have a sense of immersion in visually-based systems. It is unclear the level of realism needed for haptic technology when users can touch and feel virtual objects. A lack of realism can hinder learning in haptic-based training systems. The work will explore realism requirements for haptic device peripherals to support immersion in haptic-based environments. The investigation will draw on the relevant human-computer interaction, virtual reality and psychology literature and generate new guidelines supported with experimental results. Peripherals for several haptic-based applications will be designed, prototyped (with a 3D printer) and evaluated.
Title: Developing disaster-based virtual environments using gaming technology
Supervisor: Dr Shamus Smith
Description: Building realistic virtual environments is a complex, expensive and time consuming process. Although virtual environment development toolkits are available, many only provide a subset of the tools needed to build complete virtual worlds. One alternative is the reuse of computer game technology. The current generation of computer games present realistic virtual worlds featuring user friendly interaction and the simulation of real world phenomena. This work will investigate the reuse of computer game development tools to rapidly prototype virtual environments to simulate training in disaster zones. Previous work at Durham on fire evacuation will be extended to earthquake and flood simulation. Development issues for individual building and city-sized environments will be considered.
Title: Evaluation of haptic interaction
Supervisor: Dr Shamus Smith
Description: Advances in haptic devices have facilitated new levels of interaction by supporting computer systems where it is possible to touch and feel virtual objects and surfaces. Such system can support a rich set of possible user interactions. Thus haptic technology has been applied in a variety of applications including medical training, computer aided design, visualisations, computer games and the graphic arts. However, evaluating haptic systems can be difficult as gathering user feedback on haptic interaction by traditional methods, such as post-session interviews and questionnaires, can be error-prone if users misremember their experiences. This work will explore the difficulties of evaluating haptic-based systems, in contrast to traditional visual-based systems. New techniques and guidelines for the evaluation of haptic-based systems will be developed, supported by experimental results.
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Title: Modelling perivascular support using meshless methods
Supervisor: Dr Charles Augarde
Description: Modelling blood flow is of interest in the study of arteriosclerosis and diseases linked to heart problems. While many have modelled blood flow and the vessels themselves the surrounding (perivascular ) support to the vessels has been omitted (see here). The surrounding support may have as large an influence on flow as the properties of the vessels so omission could lead to major errors. The reason for its omission is the difficulty in modelling a semi-infinite support region which will be materially & geometrically nonlinear, and 3D. The approach we will take in this project will be to model this region using a meshless method which we have already demonstrated viable for 3D nonlinear problems in geomechanics and there is no reason why this cannot be applied to this problem. The project will involve investigation of suitable material models for the perivascular support, coding up of this into an implicit meshless code and a search for data against which to validate this approach
Title: Error estimation and adaptive strategies for the element –free Galerkin method
Supervisor: Dr Charles Augarde
Description: The element-free Galerkin method (EFGM) developed by Belytschko is perhaps the premier meshless method around today. To move meshless methods towards commercialisation in codes various problems need addressing (some of which we are currently working on here at Durham). Robust procedures for error estimation and consequent adaptive strategies are two of the items on the shopping list and these are the topics tackled in this project. We will begin by examining current error estimates in the EFG (there are not very many) and move on to development of a goal-oriented approach, as developed recently for the standard FEM and for XFEM. The project can be focussed on a number of areas, e.g. material and geometric nonlinearity, continua or fracture, but we will work in 3D from the start, making the project ambitious but exciting. There may be opportunities to work with leaders in associated fields such as Stephane Bordas at Cardiff University with whom we have links
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Title: Parallel meshless modelling using GPUs with fast solvers
Supervisor: Dr Charles Augarde
Description: The full potential of meshless methods for solid mechanics will only be realised in 3D for very large problems (multi-million degrees of freedom). So how do we get there? If we are considering implicit approaches for static problems then serial approaches using direct solvers will become inefficient before we reach the level of detail we seek in 3D. Use of iterative solvers for serial processing is the first possibility to realise our goal in this project, working from previous publications and projects in collaboration with Ramage (Strathclyde). While this will provide extensive modelling possibilities on cheap hardware platforms a greater opportunity may exist with GPU-based machines, running in parallel. Here the challenges are (a) how to adapt the basic meshless method to run in parallel on GPUs and (2) what are good solution strategies in this environment? The project work in collaboration with colleagues in Computing Sciences in our joint School
Title: Developing the material point method for modelling tunnelling
Supervisor: Dr Charles Augarde
Description: The Material Point Method (MPM) is a mixed Eulerian/Lagrangian approach for modelling in solid mechanics bringing together ideas from finite element and particle-based methods. It was first developed in the 1990s as an explicit method for dynamic problems (a good summary is provided in Guilkey & Weiss, 2003, IJNME) but it can also be used as an implicit method for statics. Its advantage is its ability to model large deformations without the mesh entanglement issues met in finite elements while avoiding some of the current drawbacks of meshless methods (such as the EFGM). In this project we would look at using the method for 3D modelling of tunnelling (something I have been doing since my own PhD) looking at deformation prediction and assessment of stability. All the work will be in 3D from the start and the PhD could focus on the application or spend some time looking at improving aspect of the MPM itself
Title: Investigating the microstructures of compacted earth building materials
Supervisor: Dr Charles Augarde
Description: The use of earthen materials for modern structures is a hot-topic due to the inherent sustainability of these materials. If we could move these materials into the same position as held by concrete and brickwork, we might be able to make major reductions in the embodied energy of structures. This requires continued scientific research to understand behaviour. Most compacted earthen materials are mixtures of soil and water with the straw, lime or cement in certain cases. Understanding the porous nature of these materials is, we think, the key to understanding sources of strength, and the changes with humidity or temperature . We will look at these materials at the particle-level and develop measures of void size distribution based on fractal approaches and develop models of microstructure development with compaction or other processes (such as water evaporation from pores). These models may be built using stochastic procedures, acknowledging the heterogeneous nature of these materials
Title: Effective conservation of rammed earth via better understanding of material behaviour
Supervisor: Dr Charles Augarde
Description: Rammed earth is an ancient construction material in use for thousands of years. Many structures exist worldwide which are hundreds of years old. Their conservation is currently a concern to engineers and archaeologists and is heightened due to the effects of climate change. We recognise that effective conservation is only likely to occur if we improve our understanding of the engineering behaviour of this material, indeed many current conservation approaches have a negative effect due to lack of understanding, particularly of the role of water. We have worked with Chris Gerrard in Archaeology at Durham since 2004 on the development of effective strategies for conservation based on rigorous understanding of the material, which we see as a manufactured unsaturated soil, informed archaeology. This project will continue our work in this area and will focus on characterisation of heritage materials involving field work and laboratory testing allied to constitutive model development
Title: Strategic design co-ordination
Supervisor: Dr Graham Coates
Description:Design co-ordination has been recognised as a new and innovative approach to managing engineering design at an operational level. However, to be truly adaptive and responsive within a dynamic and changeable setting, the organisation and control of design must also be co-ordinated in a strategic sense. This research aims to develop appropriate strategic decision-making mechanisms related to the design domain, which are able to manage the potential iteration inherent in early design
Title: Engineering team composition
Supervisor: Dr Graham Coates
Description: Description: Engineering teams in companies consist of engineers from a range of disciplines with varying levels of capability in these disciplines. The aim of this research is to develop a means of determining and modelling engineers' skills and capability such that the composition of teams can be precision-planned against the project work to be undertaken. Further, the research will aim to deliver a method of identifying shortfalls in skills and capabilities within companies such that a development strategy can be formulated
Title: Integrated conceptual aircraft design
Supervisor: Dr Graham Coates
Description:
Description: Conceptual aircraft design is a highly complex process involving engineers from different disciplines and calculations of a multitude of inter-dependent parameters that define the design under consideration. The aim of this project is to research and develop a computer-based, integrated modelling framework to assist aeronautical engineers in the conceptual design stage of an aircraft. Within the context of a conceptual aircraft design environment, the framework developed will manage complexities such as change management and version control
Title: Nuclear reactor vessel structural integrity
Supervisor: Professor Roger Crouch
Description: Pre-stressed concrete pressure vessels provide the primary barrier for gas-cooled nuclear reactors. Their structural form can be complex; the many penetrations in the side wall and top-cap of the cylindrical vessel lead to local concentrations in stress and temperature. This project involves (i) extending an existing macroscopic constitutive model to include a thermal creep capability, and (ii) identifying a means of representing the many unbonded helical pre-stressing tendons within a 3D Finite Element code. With these new features, a series of coupled deformation analyses are to be undertaken to simulate the thermal-pressure cycling of a 40-year operational life. The project would suit an engineer with a strong interest in engineering mechanics and numerical analysis.
Title: Two-surface anisotropic hypoplasticity
Supervisor: Professor Roger Crouch
Description: A generalized anisotropic inelastic constitutive model for highly porous media with a collapsible fabric is yet to be developed. This project aims to construct such a model and develop a suitable stress integration algorithm to enable the deformation behaviour of collagen scaffolds to be simulated. The macroscopic hypoplastic formulation will be built from meso-level structural analyses which will inform the nonlinear hardening law. This work forms part of a larger study into the transport and deformation properties of biological tissue.
Title: Efficient implementation of the time-domain SBFE solution
Supervisor: Professor Roger Crouch
Description: The Scaled Boundary Finite Element approach offers an attractive alternative to the Boundary Element scheme when modelling the dynamic far-field in a Finite Element fluid-soil-structure interaction problem. Yet its use requires significant computational resource in a large 3D time-domain analysis (for example, if the convolution integral is used, nodal velocities for all previous time-steps are to be stored on the SBFE interface). This project aims to arrive at a more efficient implementation (making use of a parallel FE code) so that realistic structural analyses may be undertaken within reasonable runtimes.
Title: Parallel lattice Boltzmann model of temperature-driven multi-phase flow through deforming porous media
Supervisor: Professor Roger Crouch
Description: The investigation will build upon existing work in Durham on an LB formulation. The research will involve the exploration of different methods of simulating partially-saturated flow using a lattice approach. Here decisions will need to be made as to the manner in which the capillary surfaces are represented and The solid phase deformation handled. The final code will run on a large multi-processor machine to mimic the response of the transient thermal creep of CSH gel in the wall of a nuclear reactor vessel.
Title: Material instability in elasto-visco-plastic bodies
Supervisor: Professor Roger Crouch
Description: This theoretical study will explore the role of the intermediate principal stress on (i) the strength of porous media and (ii) the orientation at which rupture planes develop under multiaxial compression. The work will explore the relevance of the acoustic tensor (or more properly, the orientation where its determinant is minimized) as a measure of fabric changes under increasing deviatoric loading at differing levels of spherical compaction. The investigation will draw upon experimental work by others and earlier fracture (or failure) criteria to deliver a clear account of the transition from localised brittle rupture to distributed ductile flow as the degree of confinement increases and intermediate principal stress alters.
Title: Use of manganese oxides to treat contaminated land
Supervisor: Dr Karen Johnson
Description: Manganese oxides are powerful natural oxidants which are capable of immobilising many heavy metals and breaking down Persistent Organic Pollutants. This project involves working with mining companies whose ‘waste' tailings are in fact pure manganese oxides. The research would build upon ongoing research in this area and would investigate the use of these manganese oxides as contaminated land remediation products. The project would suit a soil scientist or geochemist with a strong interest in geochemistry and microbiology.
Title: Use of steel slag to treat contaminated water
Supervisor: Dr Karen Johnson
Description: Steel slag is a by-product of the steel industry and currently has limited markets. It has great potential for use in many environmental engineering applications including passive treatment of mine waters and landfill leachates which contain iron and manganese. This work would focus on the re-use of the spent substrates as either potential contaminated land remediation products or as further water treatment media for the breakdown of Persistent Organic Pollutants or the immobilisation of heavy metals. This research would build upon previous work in this area on the use of ‘wastes' to treat contaminated water and land. The project would suit an environmental engineer or geochemist with a strong interest in geochemistry and microbiology.
Title: Integrated Traffic Control for Freeway Networks
Supervisor: Dr Appie Kotsialos
Description: Traffic control measures are employed for the amelioration of traffic conditions and congestion elimination. Different control measures include ramp metering, route guidance and variable speed limits. The subject of this project is the design, development and implementation in simulation (macroscopic and microscopic) and in reality, of control strategies that are able to consider the concurrent operation of different kind of spatially distributed control measures avoiding any conflicting control actions. The development of a generic software tool able to address the integrated control problem for arbitrary-topology motorway networks is part of this study. This project is suitable for engineers with strong modelling, control and numerical optimisation background. Cooperation with motorway network site operators is expected for data collection and possible implementation.
Title: Modelling and Validation of the Motorway Traffic Flow Process
Supervisor: Dr Appie Kotsialos
Description: This project is concerned with developing a software tool that will be able to use different macroscopic traffic flow models (1st, 2nd or higher order) for modelling the vehicles' traffic in arbitrary topology motorway networks. Each of these models has a number of parameters that need to be estimated based on real data obtained from the network. Model validation should be used in each case employing different optimisation methods such as genetic algorithms, simulated annealing or other evolutionary method. The impact of operating different control measures, such as variable speed limits, should be taken into account. Furthermore, prediction algorithms for demand forecasting with origin-destination information should be incorporated. This project is suitable for engineers with strong modelling and numerical optimisation background. Cooperation with motorway network site operators is expected for data collection and possible implementation.
Title: 1. Metal Spinning Process Simulation
Supervisor: Dr Hui Long
Description: Spinning is believed to have been first devised in ancient Egypt and since then has undergone transformative changes as a result of the advancement of modern CNC machines.Metal spinning has seen its increased applications for small batches of high quality components in medical, aerospace, defence, offshore and high value-added industries. One of the challenges in metal spinning is to prevent material failures during processing and to achieve required geometrical and dimensional accuracy, with sufficient production efficiency. By developing metal spinning process simulation techniques, we can explore the effects of process variables and material characteristics on the spun part quality so as to develop optimal spinning process strategies.
back to start box subsystem generally has a relatively low failure rate as compared to other subsystems. However, the gearbox has a low availability due to its high downtime per failure and gearbox failure incurs high costs for repair. To achieve a better efficiency of wind turbines and to reduce the cost of wind energy reliability prediction and failure mode analysis will be valuable for preventive maintenance of existing gearboxes. It is also essential for designing new gearbox to achieve reduced maintenance requirements and an increased reliability, especially for offshore wind turbines.
Title: 2. Effective simulation techniques of dynamic springback in spinning
Supervisor: Dr Hui Long
Description: Springback is a phenomenon in which the plastically deformed metal sheet tends to return to its original position after unloading. In metal spinning, the sheet material deforms incrementally and repeatedly under the tool forces to produce the final geometry of the spun part. The springback not only occurs at the end of the spinning process but also takes place during the dynamic process of spinning. Simulation of the in-process dynamic springback requires high computational accuracy to modelling small dimensional changes of the part, while simulation of the material elastic-plastic deformation during spinning requires high computational efficiency to model the whole duration of the spinning process. The conflict of these two requirements makes existing Finite Element (FE) methods not feasible for the simulation of dynamic springback in spinning. This PhD study will investigate effective simulation techniques and integrate with existing FE implicit and explicit solution methods to modelling the dynamic springback in spinning.
Title: 3. Effects of material cyclic loading on spinning
Supervisor: Dr Hui Long
Description: When a metal material undergoes plastic deformation under cyclic loading such as in spinning process, the material hardens until it responds more elastically in the original loading direction but softens when deformed in the opposite direction of the original loading. This phenomenon is called Bauschinger effect. The isotropic strain hardening model currently in use in our spinning simulation models could not count for this effect. Results show that there are unaccounted discrepancies between simulations and experiments. This PhD study will develop material constitutive models and FE simulation procedures to investigate the effects of cyclic loading of spinning on dimensional variations and product quality of spun parts.
Title: 4. Simulation of crack failures in spinning
Supervisor: Dr Hui Long
Description: There are three main material failures observed in metal spinning process wrinkling, circumferential cracking and radial cracking. Wrinkling is a result of the development of high compressive circumferential stresses in the flange of spun metal which leads to buckling. On the other hand, high tensile radial stresses can lead to circumferential cracks whereas radial cracks can be a result from excessive circumferential and bending stresses FE and experimental based investigation of wrinkling is currently in progress. This PhD study aims to develop appropriate material damage models for FE spinning simulation models in order to investigate how the key process parameters affect the occurrence of cracks during spinning and to develop forming limit diagrams for preventing such failure.
Title: 1. Reliability Prediction and Failure Mode Analysis of Wind Turbine Gearboxes
Supervisor: Dr Hui Long
Description: Gearbox is an important and expensive subsystem in an indirect drive wind turbine. The field reliability study of modern wind turbines shows that the gear
Title: 2. Gear failure modes and reliability prediction
Supervisor: Dr Hui Long
Description: The design of conventional gear transmissions has been well documented in the International Standards. However, for a gear system used in wind turbine
Title: Design tool for wind turbine gearboxes
Supervisor: Dr Peter Matthews
Description: The main functions of the gearbox are to transmit power from the low speed turbine shaft at high torque to the high speed generator shaft at low torque. Due to the required large transmission ratio, a gearbox typically consists of two or three stages, either planetary or parallel, to increase the speed. Various configurations of gear stages have been designed for wind turbine applications which show an improved reliability. The development of a gearbox design tool for wind turbine applications would be highly desirable to enable detailed design calculations and reliability prediction. Various gearbox design concepts using different configurations of planetary and parallel stages can be explored. This PhD study will introduce new methods in reliability prediction and develop new gear configurations based on an existing gear design software tool for wind turbine gearbox applications.
Title: Achieving Robust Design through stochastic support
Supervisor: Dr Peter Matthews
Description: Robust design is an area of increasing interest. Manufacturers benefit from being able to design and produce artefacts that will have a greater likelihood of being manufactured succesfully, as the artefacts have greater tolerance designed into them. This project will consider how to develop stochastic-based design methodologies to support designers into creating more robust designs, through the use of Bayesian modelling of the design domain. This project would suit an engineering graduate with strong interests in Artificial Intelligence methods or alternatively a statistics or computer science graduate with a general interest in design engineering.
Title: Agile Design
Supervisor: Dr Peter Matthews
Description: The concept of agility within the manufacture context is well known: it is the ability to rapidly respond to unexpected changes in the external environment. This project is part of an ongoing research theme to bring these ideas of agility to the design process. This project will investigate the nature of unexpected events within the design process and how these affect the design process. The aim is to deliver a means for creating a design environment that can respond to such unexpected events with a similar agility as in the manufacturing context. This project would suit an engineering or computer science graduate with an interest human factors and project management.
Title: Achieving Robust Design through stochastic support
Supervisor: Dr Peter Matthews
Description: Environmental legislation is resulting in modern production requirements stipulating for increasing documentation trails about the material and other resources used in manufacturing goods. The ISO-1404x standards provide guidance on the type and structure of the data that should be captured, but this is proving to be a challenge. This project aims to address these challenges by developing a resource based product model that can 'follow' material through its full life cycle. When coupled with Life Cycle Analysis tools, this will provide a powerful means for assessing the total impact a product will have on its environment. This project would suit either an engineering graduate or a computer science graduate with interests in knowledge management processes.
Title: Interactive stress analysis of solids
Supervisor: Professor Jon Trevelyan
We have developed a software tool for rapid and interactive stress analysis in 2D (see http://www.conceptanalyst.com/). The tool is based on the boundary element method (BEM) for reasons of speed and robustness of meshing and re-meshing. This has achieved a high level of interactivity because the speed of computation is sufficiently high that, when the geometry of a model is changed, the stress contours on the modified geometry can be updated in real-time. We would like to explore the potential for extension of these ideas to the analysis and re-analysis of 3D solids. We will investigate the extension of our fast numerical integration ideas from 2D to 3D, and determine substructuring, meshing and re-meshing strategies to optimise run-time. The project can be expected to make use of multi-core processing.
Title: Evolutionary structural topology optimisation of solids
Supervisor: Professor Jon Trevelyan
We have developed a set of algorithms by which a structure under a prescribed set of loads and displacement constraints may be optimised using the popular Evolutionary Structural Optimisation (ESO) method. In a recent PhD project, we have implemented this in both 2D and 3D using a BEM model superimposed on a B-spline boundary representation of the geometry (see Cervera & Trevelyan (2005), Computers & Structures, 83(23-24), 1902-1916 (Part I (2D)) and 1917-1929 (Part II (3D)). However, the 3D algorithm was only preliminary work to demonstrate the algorithm. This project will advance our understanding and development of a general algorithm for solids. It will require careful management of the boundary surface model and its evolution through the optimisation, and the development of appropriate strategies to optimise the convergence rate towards an optimum shape/topology.
Title: Interactive design analysis tool for crankshafts
Supervisor: Professor Jon Trevelyan
The crankshaft is among the most analysed of engine components. Its geometry is awkward for finite element meshing, containing toroidal fillets, oil drillings and various lightening holes and scalloped surfaces. The loading is also complicated, being determined by the cyclical motion, inertia forces and influenced by oil film thickness in the bearings. In this project we will develop an environment for the stress analysis of a crankshaft using a tailored boundary element pre-processor, and using the BEM re-analysis ideas we have developed in 2D simulations (see http://www.conceptanalyst.com).
Title: Integration schemes for 3D Partition of Unity BEM (PUBEM) in wave propagation simulation
Supervisor: Professor Jon Trevelyan
Our work in computational simulation of waves has become internationally recognised. In particular we focus on scattering problems in which the wavelength is considerably smaller than the size of the scatterer. The Partition of Unity is one of a number of approaches that have recently emerged that aim to overcome limitations of conventional FEM/BEM analysis in this situation. We have shown that the PUBEM is extraordinarily efficient in terms of the number of degrees of freedom required to solve such a problem, but is limited by the requirement to evaluate some oscillatory integrals. See http://www.dur.ac.uk/jon.trevelyan/ShortWavePage.htm. We have been exploring new strategies for computing these integrals and this PhD program will take that work further by considering a wide range of integrals that apply in different types of wave (acoustic, elastodynamic, etc.). This project would suit either an engineering or mathematics graduate.
Title: Potential for use of iterative solvers in Partition of Unity BEM (PUBEM) in wave propagation simulation
Supervisor: Professor Jon Trevelyan
Our work in computational simulation of waves has become internationally recognised. In particular we focus on scattering problems in which the wavelength is considerably smaller than the size of the scatterer. The Partition of Unity is one of a number of approaches that have recently emerged that aim to overcome limitations of conventional FEM/BEM analysis in this situation. See http://www.dur.ac.uk/jon.trevelyan/ShortWavePage.htm. We have shown that the PUBEM is extraordinarily efficient in terms of the number of degrees of freedom required to solve such a problem, but the governing matrix is ill-conditioned requiring a numerically expensive solver. However, recent work on circular scatterers in 2D has shown that if the model is defined appropriately then the conditioning improves to such an extent that much more efficient solvers can be used. Successful results have been obtained using Gauss elimination. For larger problems we will ultimately want to move to iterative solvers such as GMRES and Bi-CGSTAB. In this project we will explore the tuning of different PUBEM models to optimise their conditioning and move forward to investigate iterative solution. The work will involve the development of a preconditioning strategy for the particular character of matrix that is encountered in this method. This project would suit either an engineering or mathematics graduate.
Title: Comparison of different Partition of Unity BEM (PUBEM) formulations for short wave propagation simulation
Supervisor: Professor Jon Trevelyan
Our work in computational simulation of waves has become internationally recognised. In particular we focus on scattering problems in which the wavelength is considerably smaller than the size of the scatterer. The Partition of Unity is one of a number of approaches that have recently emerged that aim to overcome limitations of conventional FEM/BEM analysis in this situation. See http://www.dur.ac.uk/jon.trevelyan/ShortWavePage.htm. There are different ways that a boundary element approach may be formulated, though. One choice is whether to use the simpler and faster "collocation" method or the more stable "Galerkin" approach. Another choice relates to how we overcome the problem of non-uniqueness of integral equations at some frequencies - we could use the "CHIEF" method or the Combined Field Integral Equation (or Burton & Miller) approach. I would like to supervise a PhD student to undertake a detailed comparison of the different formulations. This project would suit either an engineering or mathematics graduate.
Title: Meshless methods for short wave propagation simulation
Supervisor: Professor Jon Trevelyan
Our work in developing innovative computational methods for wave problems has resulted in a new family of finite elements and boundary elements that overcome the traditional limitation that these elements can span no more than about λ/5 (λ is the wavelength under consideration). We are interested in extending the "Partition of Unity" ideas now to a meshless method using the MLPG approach of Atluri & Zhu, and implementing a plane wave expansion for the solution. This has the potential to offer a very efficient solution for wave scattering problems in inhomogeneous media.
Title: New Partition of Unity finite elements and boundary elements for short wave propagation simulation
Supervisor: Professor Jon Trevelyan
Our work in developing innovative computational methods for wave problems has resulted in a new family of Partition of Unity Method (PUM) finite elements and boundary elements that overcome the traditional limitation that these elements can span no more than about λ/5 (λ is the wavelength under consideration). Thus the elements can be very large in comparison with the wavelength. See http://www.dur.ac.uk/jon.trevelyan/ShortWavePage/htm. Accuracy of the method has been shown to be very good, but analysis of these errors shows the highest errors to accumulate around the ends of elements. We propose to develop new elements with shape functions based on a higher order of inter-element continuity to overcome this and improve the efficiency further for high frequency wave scattering. This will include the use of Hermitian and trigonometric shape functions in association with the PUM plane wav
Title: Climate change impacts on geotechnical structures
Supervisor: Dr David Toll
Description: Our climate is changing and we can expect more extreme rainfall patterns in winter months and longer, drier periods in summer months. Changes in the climate patterns will influence the seasonal variations in pore water pressures in the ground and this will have implications for serviceability and strength of geotechnical structures (road/rail embankments, dams, foundations for buildings etc). Large ranges of pore water pressure change between summer and winter will induce greater shrinkage and swelling in clay soils. There is also the possibility of increased slope failures (landslides) due to more intense storms. Possible PhD studies could involve:
(i) Field studies of pore water pressure and suction changes, involving a fully instrumented embankment
(ii) Numerical modelling of pore water pressure responses to climate change and the resulting volume change of the soil
(iii) Laboratory testing of soils using state-of-the-art suction controlled equipment for unsaturated soil testing
Title: XML data standards for geo-engineering
Supervisor: Dr David Toll
Description: The project will investigate ways to represent geotechnical data on the World Wide Web using XML. It will contribute to the GeotechML initiative (http://geotechml.com/default.aspx) to develop internationally agreed data standards for geo-engineering information. It is frequently the case that data is passed between organisations (e.g. from site investigation contractor to consultant or client) in paper form (as a report). A more efficient way to exchange data is to use electronic data files that can be directly output from geotechnical database software and can be read into other geotechnical software packages. We also need to make data available on the World Wide Web e.g. case study data. PhD studies could involve defining the data standards, providing tools for managing the data or displaying the data on the web (e.g. using Java, SVG). The intention would be to develop an inventory of case studies for geotechnical structures (slopes, retaining walls, foundations) that can form the basis of a case-based reasoning system for preliminary design.
Title: Rainfall-induced landslides
Supervisor:Dr David Toll
Description: Most landslides are triggered by rainfall infiltration. As water infiltrates, pore pressures rise (or soil suctions decrease) leading to a loss of strength, leading to slope instability. In many tropical or arid regions, soils are initially unsaturated, so the soil behaviour is dominated by significant soil suctions. The process of infiltration is governed by complex unsaturated flow processes, requiring an understanding of the water retention properties of the soils, the relationship between permeability and suction (or degree of saturation). The relationships between strength, suction and degree of saturation are also complex. A project in this area could be experimental in nature, involving determinations of water retention behaviour, permeability functions and strength making use of the state-of-the-art unsaturated soil testing equipment available at Durham University. There is also scope for a project investigating the problem computationally, using finite element modelling of the unsaturated flow processes and hydro-mechanical behaviour.
Title: Insitu measurement of water content
Supervisor:Dr David Toll
Description: In situ measurement of water content is an essential part of understanding soil behaviour in the field. While there are a number of devices available, they are bulky and the results can be affected by soil disturbance due to installing the device. This project will aim to develop a new device for water content measurement using the Time Domain Reflectometry (TDR) technique. The intention would be to investigate a coiled arrangement of electrodes that can be built into a smaller device than the conventional TDR probe, so that it can be used in conjunction with the Durham University high capacity tensiometer which is used for suction measurements. The new device would be calibrated by testing the device in the laboratory using a range of soil types (clays through to sands) over a wide range of water contents. The results would also be compared with on-going research in electrical resistivity methods for water content mapping.
Title: Engineering behaviour of unsaturated structured soils
Supervisor:Dr David Toll
Description: Many natural soils are "structured" by the presence of chemical bonds and compacted soils are "structured" by the presence of a distinct fabric (arrangements of particles). Current constitutive models of soil behaviour are very limited in their ability to combine the effects of structure with unsaturated aspects. Nevertheless, many soils exist in an unsaturated state, particularly in tropical and arid regions of the world, but also in temperate regions. In an unsaturated state the behaviour is dominated by suctions and the behaviour becomes significantly more complex. PhD studies could involve laboratory testing of soils using state-of-the-art suction controlled equipment for imposing cycles of wetting and drying and also studying structure of unsaturated soils using Environmental Scanning Electron Microscopy.
Title: The use of 3D laser scanning techniques for freeform surface measurement and data Processing
Supervisor: Dr Qing Wang
Description: Product design is a critical function of the production system. The quality of the product design is probably the most important factor in determining the commercial success and value of the product. Quite often the quality inspection will need to be performed at several places in production. A sound measurement system provides an essential foundation to the production and consequently enables the enterprises to deliver high quality products and services. Over the past ten years, the 3D measurement system has been developed rapidly with the primary requirement from the aerospace and automotive industries for measurement accuracy and efficiency. The School has a state of art measurement instrument called the laser scanner which provides automated, non-contact measurement capability for large-volume applications.
The aim of this project is to use laser scanning techniques to capture the complicated geometric shape of the parts, such as the irregular free-form curves on a turbine blade and their fine details. A series of experiments will be performed to investigate the measurement uncertainty in relation to the scan methods and scan speeds. It is expected that the student will be able to process the scan data efficiently in order to generate solid models, identify the operational features of the laser scanner and be able to develop product design rules that are compatible with the measured process capability of large and complicated components. The project would suit an engineering or computer science graduate with a strong interest in engineering measurement, reverse engineering, computer modelling and analysis.
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Title: Prediction of disassembled automotive parts using artificial intelligence
Supervisor: Dr Qing Wang
Description: The disassembly of manufactured products when combined with the repair and reuse of reclaimed components is seen as an attractive option for reducing life cycle costs and environmental impact. In addition, in order to design and plan disassembly environments (i.e. flow processing lines), it is essential that information concerning estimated job times for disassembly operations are available. Such activities and their associated job times are directly related to the state of wear of individual components and sub-assemblies.
The principal aim of this project is to investigate the application of Artificial Intelligence techniques for estimating the disassembly and repair work content of automotive components. The disassembly process will be reviewed and the disassembly model will be built, trained and tested using available test data collected from technical literature and the model will be validated to evaluate some of the input parameters on the chosen output. The project would suit an engineering or computer science graduate with a strong interest in artificial intelligent techniques, resource planning and product end of life design and development.
Title: Design and analysis of a sustainable logistic network
Supervisor: Dr Qing Wang
Description: Traditionally, marketing, planning, manufacturing, sales and distribution organisations along the supply chain have operated independently. Quite often these organisations have their own objectives and these objectives are conflicting. Many manufacturing operations are designed to maximize throughput, reduce lead time and lower costs with little consideration for the impact on inventory levels and distribution capabilities, with the result that there is not a single, integrated plan for the organization. Clearly there is a need for a mechanism through better supply chain design by which these different functions can be integrated.
The aim of this project is to review the supply network design methods of the past 40 years and identify the factors involved in operating the supply network, the outsourcing strategy used, and the balance between supply and demand that affects the inventory of changes to the replenishment strategy. It is expected that a prototype supply network model would be established which is representative of the true nature of resource flows (materials, information, production etc) in the supply chain, hence reducing the cost of the network. The project would suit an engineering or computer science graduate with a strong interest in sustainability, logistic network modelling and optimisation.
Title: Through life cost management
Supervisor: Dr Qing Wang
Description: Traditionally, the product design process has tended to concentrate on functional parameters such as dimensional geometry and structural performance evolutions, and cost has generally been neglected, even though it is widely accepted that early implementation of cost analysis models influences the design changes of the product and provides explanations of the relationships between cost and design parameters. However, there are many features of a product that can be studied using a life cycle cost analysis model. The objective of this project therefore is to develop a life cycle cost model to demonstrate the cost breakdown structures in order to identify the feasible alternatives for a cost effective design of parts/products. It is expected that the analysis will provide the mechanism for measuring the criteria or indicators that will demonstrate the cost performance or acceptability of a product to the marketplace. The project would suit an engineering or computer science graduate with a strong interest in cost engineering and product life cycle modelling.
Title: Sustainable design and manufacturing
Supervisor: Dr Qing Wang
Description: In many past situations, environmental effects were ignored during the design stage of new products and processes. The challenge of sustainable design is to alter conventional design and manufacturing procedures to incorporate environmental considerations systematically and effectively. This requires embedding corporate sustainability goals in the product design process that considers full life cycle issues such as product take back or extended producer responsibility. This project aims to develop novel assessment methods for examining the relationships between product design, production process, costs and effects associated with the “triple bottom line” of sustainability. The project would suit an engineering or business graduate with a strong interest in corporate strategy and product life cycle design and development.
Title: Technology management for underpinning innovation in enterprises
Supervisor: Dr Qing Wang
Description: In today’s highly competitive manufacturing environment, there is a need to encourage enterprises to exploit new technology-led innovation strategies to ensure longevity in the face of increased competition. Enterprise Resource Planning (ERP) systems are the predominant business management systems found in most enterprises. The proposed research is to identify the critical technological needs of the enterprise and establish a framework to support the range of tools used for the management of innovation during a product’s life cycle. The project would suit an engineering or computer science graduate with a strong interest in enterprise modelling and computer aided engineering.
Title: Performance optimisation of modelling manufacturing systems
Supervisor: Dr Qing Wang
Description: Manufacturing systems are, by nature, dynamic systems due to the underlying random effects. By applying simulation techniques, the features and attributes of such systems can be understood greatly. During the past decades, a number of optimisation methods have been developed for automated system design, considering only a single objective. However, from a system designer’s point of view, it is very desirable to obtain optimal solutions considering all the objectives. This research will use an evolutionary approach to develop a multi-objective genetic algorithm for solving the flexible process sequencing problems. The project would suit an engineering or computer science graduate with a strong interest in genetic algorithms, simulation and manufacturing systems.