Postgraduate Research Projects 2013

Engineering, especially electrical engineering, is going through a period of rapid change and expansion. What was considered state-of-the-art a few years ago is now often no more than a few lectures in one of our undergraduate courses.

The driving force behind this bewildering expansion is research, and our Department has a strong tradition of excellence in research. Research in its broadest sense is exploration of the unknown. It is the result of an idea and a belief that there is something new and exciting to be found. Research is what differentiates a true university from a teaching-only institution. In addition, we are fortunate to be situated in a progressive, high-tech community, with strong ties to national industry. A postgraduate degree can open new doors for you, particularly in research and development.

Why are we so good at research? It is the fortunate mixture of quality staff and quality students. With 24 academic staff, 20 general staff and about 70 postgraduate students we have what might arguably be the largest group of electrical engineering innovators in the country. We are proud of our past achievements and enthusiastic about our present activities and would like to share them with you.

After four years here you may be tired of studying. Let me assure you that being a postgraduate student is quite different to being an undergraduate student. There will be little or no sitting in lectures. You will conduct your own independent work with some direction and assistance from your supervisor. Postgraduate study is hard work, but it is rewarding and it is fun!

Listed here are staff members, their research interests and potential postgraduate research projects. General enquiries concerning postgraduate study can be obtained by contacting the Director of Postgraduate Studies, Dr Philippa Martin. Enquiries related to specific research areas should be addressed to the staff member concerned.

Professor Phil Bones
Head of Department

Research Areas and Staff Members Research Projects

Please click on a name to find out more about individual research projects of current staff members.

Dr Kim Eccleston

My research is in the area of microwave circuits and devices of which my current focus is on substrate integrated waveguides and integration of active devices with electromagnetic structures. Students working on microwave circuit projects have access to a well equipped microwave test facility allowing measurements up to 20 GHz, and we have academic licences for AWR Microwave Office and Sonnet. All microwave projects on offer involve experimental work. PhD candidates are expected to demonstrate mathematical rigor rather than reliance on EDA tools.

Substrate Integrated Waveguide (both ME and PhD candidates)

Substrate integrated waveguide (SIW) brings the benefits of conventional rectangular waveguide to planar circuit technology. Of interest is SIW couplers, meshed conductor SIW, corrugated SIW, and eigenvalue analysis of SIW structures.

Magnetic fields in corrugated SIW

Solid (left) and meshed conductor SIW

Integration of Active Devices with Electromagnetic Structures (both ME and PhD candidates)

The aim of this work is to integrate active devices with specialised electromagnetic structures. The electromagnetic structures are designed to be compatible with the transistors and serve multiple functions. Of interest is periodic and fractal structures, and distributed power amplification.

Microwave Metamaterials (both ME and PhD candidates)

Metamaterials are currently a hot topic of microwave engineering as they exhibit a number of interesting properties not seen in conventional materials. Of interest is large 2D metamaterial structures, zero-phase-shift metamaterials, miniaturisation of metamaterial unit cells, passive and active circuits that exploit 2D metamaterials.

Wave propagation through a zero-phase shift metamaterial lens

Efficient Microwave Power Amplifiers (most suitable for ME candidates)

The microwave power amplifier of wireless devices consumes the most power from the battery and therefore its efficiency has a significant impact on talk-time or duration between battery recharges. Of interest is waveform shaping to achieve high output power and efficiency, Doherty power amplifiers, dynamic biasing schemes, and harmonic and intermodulation injection.

Selected Publications:

UC Research Profile

Assoc Prof Philippa Martin

My research focuses on the analysis, design and simulation of cutting-edge wireless communication systems (primarily for the physical layer). My key active research areas are error correction coding/ decoding, coded modulation and lattices, combined equalization and decoding, iterative processing, space-time coding and receiver design (detection, equalization and decoding), multi-user detection, cooperative and distributed communication systems and cognitive radio. I have a variety of ME and PhD research projects available in these and related areas as shown below. Students can also develop their own research projects in these areas. Interested students should contact me to discuss potential projects. In addition, industry related projects are periodically available in conjunction with the wireless research centre (WRC).

COMMUNICATION NETWORKS (Co-supervised by Dr Andreas Willig, CSSE Department)

In the past, communication networks tended to have fixed topologies and the network layer was optimized separately from the physical layer. Today researchers and industry are faced with much more diverse and complex communication systems. In addition, expectations on performance and data rate have increased. This has opened up new research areas including the design of distributed and cooperative communication systems, network coding and cross-layer optimization. This leads to a number of interesting research problems with application to mesh and sensor networks, relay channels and RFID. This is one of the hottest research areas at the moment. A selection of the available research projects in these areas is given below:

Analysis and Systems Design for Systems with Multiple Hops, Users and Relays

Only recently have researchers started to consider large relay network from a physical layer perspective. There are some interesting research projects available looking at how to design and analyse systems with multiple hops, users and relays.

Design of Advanced ARQ Schemes

Another important type of cross-layer design is that of ARQ schemes. In these projects innovative ARQ schemes will be developed for various environments using advanced error control coding techniques.

LARGE COMMUNICATION SYSTEMS (Co-supervised by Assoc Prof Peter Smith)

Our everyday lives involve numerous devices using some form of communications. Most of us immediately think of landline telephones, cellphones and computer/ internet. However, appliances, vehicles, containers and machines are examples of other objects that are increasingly communicating with objects, computers or people. As a result, there is an emerging “ocean of devices” consisting of trillions of wireless devices. Not only will there be human initiated or directed communications, but also machine to machine communications. We are moving into an era of cognitive ubiquitous communications, where a network should be able to choose, adapt and change with time.

Here we are considering a communication environment with a large number of transmitting antennas from multiple users/ devices. At the receiver(s) there are a large number of signals to separate and detect. This gives rise to some interesting multi-user detection problems. Multi-user detection is not a new problem, but when very large systems are considered computational complexity becomes a serious issue. This gives rise to some interesting algorithm design problems, mathematical derivation and analysis problems, and opportunities for experimental testing via simulation. In addition, there are questions on the best overall system design. As can be seen, there are a number of interesting problems to work on.

COGNITIVE RADIO SYSTEMS (Co-supervised by Assoc Prof Peter Smith)

Radio spectrum is expensive to buy and the (currently) useable frequency range is limited. However, vast amounts of spectrum are under-utilized by the licensed user. The idea behind cognitive radio systems is to allow secondary users to use the spectrum when the primary user is not. Hot research topics in this area include: spectrum sensing, interference mitigation, position information, security issues and business models.

MULTIPLE ANTENNA SYSTEMS (Co-supervised by Professor Des Taylor)

Multiple transmit antennas can be used in fading environments to increase throughput and/ or improve performance. These are called MIMO or space-time systems. A small selection of available projects in this area is outlined below:

Multiuser MIMO

To date the majority of research on MIMO and space-time systems has assumed a single user scenario. Communication systems often need to support multiple users. In these projects several aspects of multiuser MIMO will be considered including code design, detection, channel estimation and equalization. The overloaded case, where there are more transmitted signals than receiving antennas is of particular interest. This research is part of an ongoing research programme.

High Rate Space-Time Codes with Manageable Decoding Complexity

Initially many of the space-time coding schemes were designed to provide up to one symbol per time slot using more than one transmit antenna. More recently researchers have begun to investigate how higher rate codes can be developed while still maintaining feasible decoding complexity. In these projects new high rate space-time transmission systems will be designed with appropriate reduced complexity detection/ decoding algorithms.

Coded Modulation for Space-Time Systems

Error correction coding and modulation can be combined to produce more bandwidth efficient communication systems. In these projects various aspects of coded modulation for space-time systems will be investigated, including code design, code searches, partitioning, optimization, detection, equalization and decoding strategies.

Adaptive Space-Time Code Design

If information about the current channel condition is available at the transmitter, then the transmitted signal can be designed for the current conditions. This allows performance to be improved. These are called adaptive space-time codes as they adapt to the channel conditions. In these projects new adaptive space-time coding schemes and their decoders will be developed.

ERROR CONTROL CODING (Co-supervised by Professor Des Taylor)

Error control coding is used to increase reliability at the cost of throughput. This is achieved by adding redundancy (non-data symbols) to the data to be transmitted. The error control decoder uses this redundancy to detect and/ or correct errors in the received signal. Error control coding is used in many of the projects already listed. In addition, I offer the following projects:

Design of high rate concatenated codes for wireless applications.
List based processing in fading environments.

ULTRA-WIDEBAND COMMUNICATIONS (Co-supervised by Professor Des Taylor)

An ultra-wideband communication signal occupies more than 500MHz bandwidth typically in the 3.1-10.6GHz frequency band. This on-going research project considers the design of spreading sequences and error control coding for UWB communications. This research is in collaboration with researchers from the University of Plymouth, UK.

As you can see there are lots of exciting projects on offer. The descriptions given are vague because this document is put online and I also believe students should be involved in the design of their project.

Note: I am happy to co-supervise projects on POWER-LINE COMMUNICATIONS and IMAGE TRANSMISSION, but a suitable co-supervisor must be found before the degree is started. The University requires there to be two supervisors for each ME/ PhD student.

Recent International Journal Publications

M. Baghaie A., P.A. Martin and D.P. Taylor, “On multilevel space-time trellis codes”, IEEE Commun. Letters, 2010.

R. Lin, P.A. Martin and D.P. Taylor, “Cooperative signaling with soft information combining”, Journal of Electrical and Computer Engineering, vol. 2010, Article ID 530190, 5 pages, 2010. doi:10.1155/2010/530190.

M. Krause, D.P. Taylor and P.A. Martin, “On bounding the performance of group-wise multiuser detectors”, IEEE Commun. Letters, vol. 13, No. 12, pp. 938-940, Dec. 2009.

P.A. Martin and D.P. Taylor, “Comments Regarding “On the performance/ complexity tradeoff in block Turbo decoder design”, IEEE Trans. Commun., Vol. 57, No. 9, pp. 2517, Sept. 2009.

P.A. Martin, M.A. Ambroze, D.P. Taylor and M. Tomlinson, “Coding for shared satellite channel communications”, IEEE Trans. Commun., Aug. 2009.

Recent International Conference Publications

R. Lin, P.A. Martin and D.P. Taylor, "Two-user cooperative transmission using superposition modulation and soft information combining", to be presented at VTC-fall, Ottawa, Canada, 6-9 Sept. 2010.

M. Krause, D.P. Taylor and P.A. Martin, “An Iterative List Multiuser Detector for Overloaded Receivers in a Rayleigh Fading Channel”, ICC, Dresden, Germany, 14-18 June 2009.

Recent Thesis Completions

Xiao Ma, “Spectrum sensing based on sequential testing”, ME 2009.

Gayathri Kongara, “Space-frequency equalization in broadband single carrier systems”, PhD 2009.

Li Zhou, “Low complexity MLSE receiver for CPM with receive diversity”, ME 2009.

Michael Krause, “Signal detection for overloaded receivers”, PhD 2009.

Marjan Baghaie, “Multilevel space-time trellis codes for Rayleigh fading”, ME (with distinction) 2008.

Yu Gu, “Noncoherent communications using space-time trellis codes”, ME 2008.

For a full publication list (2000-2010) please visit my web page at http://www.elec.canterbury.ac.nz.

Professor Peter Smith

Several ME and PhD topics, mainly in the area of wireless communications. Most projects would involve collaboration with other researchers, both in New Zealand and overseas. Prospective students should be keen to compete with the best in the world and be aware that some industrial scholarships may be available. In particular, topics include:

Cognitive radio: detectors, models, relays and performance.
MIMO relay methods.
Transmit diversity, including channel inversion and SVD transmission.
Beamforming and block-diagonalization with MIMO systems.

Notation: MIMO = multiple-input-multiple output, i.e. where multiple antennas are used at the transmitter and the receiver.

Publications

Smith, P.J., King, T.W., Garth, L.M., Dohler, M. (2008) A Power Scaling Analysis of Norm-Based Antenna Selection Techniques. IEEE Transactions on Wireless Communications, 7, 6.

Suraweera, H.A., Gao, J., Smith, P.J., Shafi, M., Faulkner, M. (2008) Channel Capacity Limits of Cognitive Radio in Asymmetric Fading Environments. Beijing : IEEE International Conference on Communications, 19-23 May, 4048-4053.

Kongara, K.P., Smith, P.J., Garth, L.M. (2008) Eigenvalue variation in MIMO OFDM systems. Christchurch: Australian Communications Theory Workshop, Jan. 30 - Feb. 1, 82-87.

Suraweera, H.A., Smith, P.J., Surobhi, N.A. (2008) Exact Outage Probability of Cooperative Diversity with Opportunistic Spectrum Access. Beijing: IEEE International Conference on Communications Workshops, 19-23 May, 79-84.

McKay, M.R., Smith, P.J., Suraweera, H.A., Collings, I.B. (2008) On the Mutual Information Distribution of OFDM-Based Spatial Multiplexing: Exact Variance and Outage Approximation. IEEE Transactions on Information Theory, 54, 7, 3260-3278.

Kongara, K.P., Kuo, P-H., Smith, P.J., Garth, L.M., Clark, A. (2008) Performance Analysis of Adaptive MIMO OFDM Beamforming Systems. Beijing: IEEE International Conference on Communications, 19-23 May, 4359-4365.

Smith, P.J., Suraweera, H.A., Shafi, M. (2008) Signal power variation with applications to cognitive radio. Christchurch: Australian Communications Theory Workshop, Jan. 30 - Feb. 1, 33-38.

Kuo, P-H., Smith, P.J., Garth, L.M. (2007) A Markov Model for MIMO Channel Condition Number with Application to Dual-Mode Antenna Selection. Dublin: IEEE Vehicular Technology Conference, 22-25 April, 471-475.

Webb, R.Y., Smith, P.J. (2007) A Population Monte Carlo Method for Generating Random Matrices with Known Characteristics. Las Vegas : International Conference on Machine Learning: Models, Technologies, June 25-28, 139-145.

McKay, M.R., Smith, P.J., Suraweera, H.A., Collings, I.B. (2007) Accurate Approximations for the Capacity Distribution of OFDM-Based Spatial Multiplexing. Glasgow: IEEE International Conference on Communications, 24-28 June, 5377-5382.

Zhang, M., Smith, P.J., Shafi, M. (2007) An Extended One-Ring MIMO Channel Model. IEEE Transactions on Wireless Communications, 6, 8, 2759-2764.

King, T.W., Smith, P.J., Garth, L.M. (2007) Capacity and Fairness of MIMO Broadcast Algorithms in Shadow Fading Environments. Washington: IEEE Global Telecommunications Conference, 26-30 Nov., 3617-3622.

Smith, P.J., Garth, L.M. (2007) Distribution and characteristic functions of correlated complex Wishart matrices. Journal of Multivariate Analysis, 98, April 2007, 661-677.

Smith, P.J. (2007) Exact Performance Analysis of Optimum Combining With Multiple Interferers in Flat Rayleigh Fading. IEEE Transactions on Communications, 55, 9, 1674-1677.

Clark, A., Smith, P.J., Taylor , D.P. (2007) Instantaneous Capacity of OFDM on Rayleigh-Fading Channels. IEEE Transactions on Information Theory, 53, 1, 355-361.

Kuo, P-H., Smith, P.J., Garth, L.M. (2007) Joint Density for Eigenvalues of Two Correlated Complex Wishart Matrices: Characterization of MIMO Systems. IEEE Transactions on Wireless Communications, 6, 11, 3902-3906.

Xiang, M., Smith, P.J., Shafi, M. (2007) MIMO mutual information: The effects of different system factors and cellular applications. Adelaide: Australian Communications Theory Workshop, 5-7 Feb.

Smith, P.J., Garth, L.M., Shafi, M. (2007) Performance analysis of multiple-input multipleoutput singular value decomposition transceivers during fading and other cell interference. IET Microwaves, Antennas & Propagation, 1, 6, 1111-1119.

Choi, S.H., Smith, P.J., Allen, B., Malik, W.Q., Shafi, M. (2007) Severely Fading MIMO Channels: Models and Mutual Information. Glasgow: IEEE International Conference on Communications, 24-28 June, 4628-4633.

Professor Desmond Taylor

My research deals primarily with the development of advanced wireless communications systems. This includes work on coded signalling, adaptive transceiver structures and software defined radios including cooperative and cognitive or smart radio systems. The following lists a number of projects that indicate the scope of the work and interested students should contact me to discuss possible projects. The research includes both theoretical and practical projects and many variations on these are possible.

Cognitive Radio Systems

Software radios are emerging as platforms for “smart” multi-band multimode wireless systems. Cognitive radio extends software radio to model-based reasoning interference and its avoidance. This transforms radio nodes into radio-domain-aware intelligent agents that make opportunistic use of radio spectrum and allow multiple systems to occupy the available frequency space in a non-interfering manner. This work, which may involve multiple projects, will develop novel wireless systems based on cognitive radio concepts.

MIMO Systems using Multi-Amplitude Minimum Shift Keying (MAMSK)

Modern disaster recovery efforts require rapidly deployable high-capacity data networks. One possibility for this is space-time coded multiple-input-multiple-output (MIMO) radio systems employing MAMSK. This modulation has the trellis properties of MSK but uses multiple amplitude levels. The project will build on previous research that has developed MIMO systems using continuous phase modulation (CPM), a relative of MSK. Some of our recent research has developed CPM-based, space-time codes that achieve spectral efficiencies of 6 bits per channel use and higher efficiencies may be achievable using MAMSK.

Estimator Detector Receivers for MIMO

Recent work on MIMO systems has lead to the idea of training codes . These are space-time code structures that incorporate training into the code structure in various ways. The resulting estimator detector structures may be viewed as an advanced form of the estimator correlator receiver structures developed originally by Kailath. This project will develop and evaluate novel estimator detector structures for multiple-input-multiple-output (MIMO) systems incorporating training code concepts. This project involves the development of advanced communication theory concepts and is well suited to a PhD student.

Capacity Analysis for Cooperative Radio Systems

Cooperative coding and transmission in a two-user system is the current focus of an ongoing project. However, the channel capacity limits for this and similar schemes are unknown. Some recent work has analysed the capacity of a two-user system when a “genie” provides each user with a copy of the other user's message. However, this is an unrealistic scenario. A more realistic one occurs when a user has no knowledge of the other, but does have knowledge of the other user's code. This project will develop a capacity analysis for cooperative systems where each user knows only the coding scheme of other users. This project will require significant analytical ability. (Co-supervised by Dr Philippa Martin).

Multi-User Detection Algorithms

Modern high speed wireless transmission is often in a multi-user environment and employs both transmit and receive diversity. Moreover, many systems operate under so-called overload, where there are more signals present than there are antennas and receivers. Current research is focused on the use of near-optimal list decoding approaches. It is intended to extend this to the development of multi-user detection coupled with joint equalization and decoding algorithms. This project is best suited to a PhD student.

Combined Decoding and Equalization Studies

There is currently an ongoing project focused on the development of combined equalization and decoding techniques. However, several alterative approaches to this problem are possible, depending on the channel environment and the signalling format. Possible projects include developing new coded schemes for use in a MIMO or space-time coded environment. The work includes the development of high-performance channel estimation and new coded signalling approaches. Several projects are possible to investigate some of these and to develop new high-performance solutions with manageable complexity.

Assoc Prof Maan Alkaisi

In addition to my position at the Department of Electrical and Computer Engineering, I am a Principal Investigator at the MacDiarmid Institute for Advanced Materials and Nanotechnology.

My research interest involves developing new technologies and processes for making nanostructures and nanoscale devices. These include three dimensional patterns using nanoimprint lithography, trapping and imaging of biological cells for early detection and diagnosis, and surface modifications of solar cells. We host in our Nanofabrication laboratories a number of key fabrication and testing equipments these include: Electron Beam Lithography machine (Raith 150), high precision optical Mask Aligner (Karl Suss MA6), versatile Sputtering system with DC/RF co-sputtering and Electron Beam Evaporation capability (AUTO500), a UV Nanoimprint Lithography machine UVNIL (EVG620), a Laser Mask writer, Dektak 150 surface profiler, and a new AFM is on order. For a complete list of equipments refer to our web page at: www.elec.canterbury.ac.nz/research/nest .

We have been successful in securing funding for the next five years 2008-2014 through the MacDiarmid Institute for Advanced Materials and Nanotechnology. A newly refurbished nanofabrication lab has just been opened this year.

Nanoimprint Lithography of Textured Surfaces for Photovoltaic Applications (Nanotechnology) (PhD Project)

Nanoimprint lithography (NIL) is considered one of the most promising techniques for the manufacturing of next generation devices and nanostructures. Features below 10 nm have already been defined by NIL. We are interested in developing processes for making three dimensional structures at the nanometre scale using NIL.

AFM images of 3D features defined on a quartz mold (left) and imprinted in resist (right)

A silicon surface textured with subwavelength pyramid like structures using interferometeric lithography and corresponding reflections from the surface after texturing

In this project we will investigate the use of Nanoimprint lithography for patterning sub-wavelength light trapping structures. It is known that sub-wavelength structured surfaces with periods smaller than the visible wavelength of light, behave as antireflection surfaces. These structures have been patterned in the past using electron beam lithography and because of that have limitation on the size and throughput of the solar cell production. Sub-wavelength structures have surface relief with period in the order of 150 to 200 nm and depth of 300nm. The shallow depth requirement will enable texturing with negligible etching damage. NIL offers high throughput, low cost with no limitations on the size or type of cell material which is very suitable for energy conversion devices where cost is considered a prime factor. Electron beam lithography, interferometric lithography and dry etching will be used to fabricate the master mold on quartz substrates. The combined advantages of using Nanoimprint and sub-wavelength texturing in solar cells fabrication is very attractive to the solar cell manufacturing companies and has high potential for commercialisation (annual growth in 2008 is 110% in the PV market).

Fabrication of Thin Film Solar Cells on Pre-textured Substrates

Thin film solar cells offer low cost fabrication and are attractive alternatives to crystalline materials. Deposition of the active thin film silicon material on pre-textured substrates will be investigated using reactive sputtering techniques. A novel thin film solar cells structure where layers of Al doped ZnO and thin films of silicon will be investigated in this study. A versatile sputtering system with DC and RF magnetron sources and electron beam evaporation facilities will be utilised for this purpose. Reactive dry etching technique will be used for texturing substrate surfaces to reduce reflections and form the starting layer.

Development of Lab on Chip for Single Cell Analysis and Imaging (Bionanotechnology, PhD Project)

The development of microarrays for analysis and manipulation of cells or viruses has attracted considerable interest from both researchers and industry.

We have recently developed a novel technique for replicating biological cellular and sub cellular structures. This method facilitates imaging individual cells at high resolution and offers a snap shot record of cell response to stimulus. Termed Bioimprint, it has enabled us to detect features of fusion pores in cells at unprecedented resolution down to the nanometre scale. In combination with our BioChip platform, which traps individual cells in its cavities, we are creating a very powerful tool for single cell analysis.

The project is in collaboration with Christchurch School of Medicine, Industrial Research Ltd and the New Zealand Institute for Plant and Food Research and lead by the team at the University of Canterbury . This has the potential to enable the early detection of abnormalities in cells and to yield novel cell-culture scaffolds.

Publications

Chapters in Books

Alkaisi, M.M, Mohamed, K. Chapter title: Three dimensional patterning using UV nanoimprint Lithography, Book Title: Lithography, IN-TECH, Vienna, Austria, accepted for publication, 2009.

Alkaisi, M.M. Blaikie, R.J. Book Title: Micromanufacturing and Nanotechnology, Springer-Verlag, Germany, Chapter 17, “Nanolithography in the Evanescent Near Field”, Page 395-422, Sept. 2005, ISBN: 3-540-25377-7.

Recent Refereed Publications

Alkaisi, M.M., Muys, J.J., Evans, J.J., “Single cell imaging with AFM using Biochip/Bioimprint Technology” 2009 Invited paper, Special Issue of International Journal of Nanotechnology on New Zealand Science, Issue 3-4, Vol, 6, 355-368, (2009).

K. Mohamed, M.M. Alkaisi and R.J. Blaikie, “Surface charging suppression using PEDOT/PSS in the fabrication of three dimensional structures on a quartz substrate” Microelectronic Engineering, Vol 86, 535-538, (2009).

K. Mohamed, M.M. Alkaisi and R.J. Blaikie “The replication of three dimensional structures using UV curable nanoimprint lithography (UV-NIL)”, J.V.S.Technol, B, V. 26, Issue 6, 2500-2503, Nov. (2008).

Wang, W.H., Alkaisi, M.M., Liu, X.Y., Sun, Y., Chase, J.G., Chen, X.Q, Hann, C., “Suspended Cell Patterning for Automatic Microrobotic Cell Injection” IEEE/ASME MESA, IEEE/ASME International Conference on Mechatronic and Embedded Systems and Applications, Oct 12-15, 2008 Beijing, China, Source: Proceedings of 2008 IEEE/ASME International Conference on Mechatronic and Embedded Systems and Applications, 100-105, (2008).

Alkaisi, M.M., Muys, J.J., Evans, J.J., “ Invited paper ” “Bioimprint Replication of Single Cells on a Biochip”, BioMEMs and Nanotechnology, Proc of SPIE, Vol 6799, U212-U221, (2007).

Schuler, L.P., Valanoor, N., Miller, P., Guy, I., Reeves, R., Alkaisi, M.M., “The effect of substrate material and post-annealing on the photoluminescence and piezo properties of DC sputtered ZnO” Journal of Electronic Materials, March 22, ISSN 0361-5235, (2007).

Siriwongrungson, V., Alkaisi, M.M., Krumdieck, S.P., “Step coverage of thin Titania films on patterned silicon substrate by pulsed–pressure MOCVD”, Surface and Coating Technology, 201, 8944-8949, (2007).

Mohamed, K., Alkaisi, M.M. and Blaikie, R.J., “The fabrication of 3D structures for a UV curable nanoimprint (UV-NIL) mold using variable dose control with critical energy electron beam exposure”, J.Vac.Sci.Technol.B, 25, 2357-2360, (2007).

Allen, M.W., Miller, P., Metson, J.B., Reeves, R.J., Alkaisi, M.M., Durbin, S.M., “Schottky contact behaviour as a function of metal and ZnO surface polarity”. Symposium on Zinc Oxide and related materials, MRS, Nov 27-30, 2006 Boston MA, Zinc Oxide and Related Materials, Vol 957, 149-154, (2007).

Siriwongrungson, V., Krumdieck, S. and Alkaisi, M.M., "Pulsed-Pressure MOCVD Processing Investigation for TiO 2 Films on Si 3 N 4 Substrate”, Accepted for publication in ECS Transactions, Volume 25, EuroCVD 17, Vienna, Austria, 2009.

Mohamed, K., Alkaisi, M.M., Blaikie, R.J., “A three-dimensional Ultraviolet Curable Nanoimprint Lithography (3D UV-NIL)”, Accepted for publication in AIP Conference Proceedings, AMN4, 4th Advanced Materials and Nanotechnology Conference, 8-12 February 2009, Dunedin, New Zealand.

Samsuri, Fahmi, Mitchell, John S., Alkaisi, Maan M, Evans, John J. “Replication of Muscle Cell Using Bioimprint”, Accepted for publication in AIP Conference Proceedings, AMN4, 4th Advanced Materials and Nanotechnology Conference, 8-12 February 2009, Dunedin, New Zealand.

Cheng, H.H., Alkaisi, M.M., Wu, Shang-En and Liu, Chuan-Pu (2009) “Fabrication of bismuth nanowire devices using focused ion beam process", Accepted for publication in AIP Conference Proceedings, AMN4, 4th Advanced Materials and Nanotechnology Conference, 8-12 February 2009, Dunedin, New Zealand.

Dr Martin Allen

UV Photodiodes (ME/PhD Projects)

Want a chance to work on a cutting edge semiconductor project which also has potential health benefits for all New Zealanders? New Zealand has a unique climatology resulting in extreme levels of sun burning (erythemal) UV radiation in the summer and very low levels of vitamin D producing UV during the winter. The former is responsible for world leading skin cancer rates amongst pakeha New Zealanders while the latter may be partly responsible for the high rates of cancer, diabetes, and heart disease particularly amongst people of maori and pacific island decent. We urgently need reliable and affordable tools for monitoring both erythemal and vitamin D weighted UV radiation. In this project, you will design, fabricate, and characterise UV photodiodes using the ZnMgO semiconductor system whose spectral responsivity can be compositionally tuned across the UV spectrum. This work will take place in the department's world class nanofabrication laboratory using our proven and provisionally patented Schottky diode fabrication technology and ZnMgO material grown using the University of Canterbury molecular beam epitaxy (MBE) system. The resulting photodiodes will be deployed in electronic UV monitoring badges and real time UV displays which will be used in schools to teach young New Zealanders about the risks and benefits of UV exposure.

Radiation Resilient, High Temperature Devices (ME/PhD Projects)

Ever wanted to put something into space? This could be your chance! Most conventional, silicon-based, electronic devices have a hard time coping with the high radiation levels and extreme temperatures found in space. ZnO is a radiation resilient, wide band gap semiconductor that is a strong candidate for high temperature electronic devices that can reliably operate in space and other harsh environments. We have recently developed a world leading and provisionally patented technology for the fabrication of high quality Schottky contacts to ZnO. Schottky contacts are the key components in a number of potential devices such as power diodes, transistors, and nanoscale power generators. In this project, you will design, fabricate, and test prototype devices which will be used to provide the ‘proof of concept' for ZnO as a ‘space age' semiconductor. This work will take place in the department's world class nanofabrication laboratory using ‘state of the art' lithographic, material growth, and device characterisation tools.

Related Publications

M.W. Allen and S.M. Durbin, “Influence of oxygen vacancies on Schottky contacts to ZnO,” Applied Physics Letters 92, 122110 (2008).

M.W. Allen, S.M. Durbin and J.B. Metson, “Silver oxide Schottky contacts on n-type ZnO,” Applied Physics Letters 91, 053512 (2007).

M.W. Allen, M.M. Alkaisi and S.M. Durbin, “Metal Schottky diodes on Zn-polar and O-polar bulk ZnO,” Applied Physics Letters 89, 103520 (2006). (Selected for the 18 September 2006 issue of the Virtual Journal of Nanoscale Science and Technology 14 (12) 2006).

Dr Volker Nock

My research interests include micro and nano-fabrication, surface patterning and their application to Lab-on-a-Chip type devices. As part of my association with the MacDiarmid Institute for Advanced Materials and Nanotechnology I am involved in a variety of projects on microfluidics and related technologies. Research projects (ME/PhD) are available in the following areas:

Control and Measurement of Oxygen in Microfluidic Devices

Dissolved oxygen (DO) is an important parameter with significant effect on cellular development and function. Microscale laminar flow and hydrodynamic focusing provide ideal tools for the generation of controlled chemical micro-environments and their application as stimuli to cells. Building upon the DO sensor patterning process and flow control devices developed in the Department, we are currently working on a variety of Lab-on-a-Chip (LOC) devices capable of controlling and measuring the cellular oxygen micro-environment.

We have recently demonstrated the fabrication of sensor patterns with dimensions of one micrometer and below. This, for example, enables one to position arrays of oxygen sensor patches underneath individual cells. Together with collaborators at the Christchurch School of Medicine we will be using these sensors in integrated devices to investigate the effect of oxygen on endometrial cancer cells, their proliferation and resistance to therapy. In addition, these oxygen sensing LOCs will be evaluated to study the role of oxygen in cartilage cell and stem cell differentiation capacity.

oxygen

Selected Publications

Nock, V. and Blaikie, R.J. (2010) Spatially-Resolved Measurement of Dissolved Oxygen in Multi-Stream Microfluidic Devices. IEEE Sensors Journal 10(12): 1813-1819. http://dx.doi.org/10.1109/JSEN.2010.2049016.
Nock, V., Alkaisi, M.M. and Blaikie, R.J. (2010) Photolithographic patterning of polymer-encapsulated optical oxygen sensors. Microelectronic Engineering 87(5-8): 814-816. http://dx.doi.org/10.1016/j.mee.2009.11.076.
Nock, V., Blaikie, R.J. and David, T. (2008) Patterning, integration and characterisation of polymer optical oxygen sensors for microfluidic devices. Lab on a Chip 8: 1300-1307. http://dx.doi.org/10.1039/b801879k.

Force Pattern Characterization in Moving Micro-Organisms

Caenorhabditis elegans is a well established model organism and has been gaining interest particularly related to worm locomotion and the investigation of the relationship between muscle arms and the motion pattern of the nematode. We have developed a micropillar-based on-chip system which is capable of quantifying multi-point locomotive forces of a moving C. elegans.

A Polydimethylsiloxane (PDMS) device was microfabricated to allow C. elegans to move in a matrix of micropillars in a channel, and an image processing method was developed to resolve the worm force from the bending pillars (see video). The current micropillar-based system is able to measure force with a resolution of 1.75 µN for body width of 80 µm. Initial experiments have been conducted to collect a maximum force level for five wild type worm samples. Currently we are working on the creation of a fully integrated microfluidic platform for high-throughput nematode studies.

celegans

Selected Publications

Johari, S., Nock, V., Alkaisi, M.M. and Wang, W. (2013) On-chip analysis of C. elegans muscular forces and locomotion patterns in microstructured environments. Lab on a Chip 13: 1699-1707. http://dx.doi.org/10.1039/C3LC41403E.
Ghanbari, A., Nock, V., Johari, S., Blaikie, R.J., Chen, X-Q. and Wang, W. (2012) Micropillar-based on-chip system for continuous force measurement of C. elegans. Journal of Micromechanics and Microengineering 22(9): 095009. http://dx.doi.org/10.1088/0960-1317/22/9/095009.
Johari, S., Nock, V., Alkaisi, M.M. and Wang, W. (2011) High-Throughput Microfluidic Sorting of C. elegans for Automated Force Pattern Measurement. Materials Science Forum 700: 182-187. http://dx.doi.org/10.4028/www.scientific.net/MSF.700.182.
Ghanbari, A., Nock, V., Blaikie, R., Chase, J.G., Chen, X.Q., Hann, C.E. and Wang, W. (2010) Force pattern characterization of C. elegans in motion. International Journal of Computer Applications in Technology 39(1/2/3): 137-144. http://dx.doi.org/10.1504/IJCAT.2010.034742.

Self-Propelling, Coalescing Droplets

Microfluidic devices play an ever increasing role in nano- and biotechnologies. An emerging area of research in this technology-driven field is digital microfluidics which is based upon the micromanipulation of discrete droplets. Microfluidic processing is performed on unit-sized packets of fluid which are transported, stored, mixed, reacted, or analyzed in a discrete manner.

An obvious challenge however is how to displace droplets on a substrate. Recently, we have proposed and confirmed a novel propulsion method based on the coalescence of droplets with different surface tensions (see video1 and video2). By locally modifying the surface energy of a substrate it is possible to control the trajectory of the droplets and we are currently working on applying this propulsion mechanism to integrated droplet-based microfluidic LOCs for biomedical analysis.

droplets

Selected Publications

Sellier, M., Nock, V., Gaubert, C. and Verdier, C. (2013) Droplet actuation induced by coalescence: Experimental evidences and phenomenological modeling. The European Physical Journal Special Topics 219: 131-141. http://dx.doi.org/10.1140/epjst/e2013-01788-0.
Sellier, M., Nock, V. and Verdier, C. (2011) Self-propelling, coalescing droplets. International Journal of Multiphase Flow 37(5): 462-468. http://dx.doi.org/10.1016/j.ijmultiphaseflow.2011.01.001.

Surface Modifications and Cell-Substrate Interactions

Polymeric substrates have the ability to influence attachment, proliferation and gene expression of anchorage-dependent cells. Surface modification techniques which regulate re-differentiation of expanded stem cells would be of significant clinical importance.

We are currently investigating various methods of surface modification including both chemical (diazonium salt chemistry, ECM stamping) and physical techniques (elastomeric stencils, micro and nano-patterns and Bioimprint) regarding their suitability for cell culture and effect on cell development. These techniques involve the adaptation of microfabrication technology and microfluidic flow phenomena to surface patterning (see more images) and cell culture.

stencils

Selected Publications

Murray, L.M., Nock, V., Alkaisi, M.M., Lee, J.J.M. and Woodfield, T.B.F. (2012) Fabrication of polymeric substrates with micro- and nanoscale topography bioimprinted at progressive cell morphologies. Journal of Vacuum Science and Technology B 30: 06F902. http://dx.doi.org/10.1116/1.4758759.
Nock, V., Murray, L., Samsuri, F., Alkaisi, M.M. and Evans, J.J. (2011) Microfluidic arrays for bioimprint of cancer cells. Microelectronic Engineering 88(8): 1828-1831. http://dx.doi.org/10.1016/j.mee.2010.12.042.
Nock, V., Murray, L., Samsuri, F., Alkaisi, M.M. and Evans, J.J. (2010) Microfluidics-assisted photo nanoimprint lithography for the formation of cellular bioimprints. Journal of Vacuum Science and Technology B 28(6): C6K17-C16K22. http://dx.doi.org/10.1116/1.3501342.
Flavel, B.S., Gross, A.J., Garrett, D.J., Nock, V. and Downard, A.J. (2010) A Simple Approach to Patterned Protein Immobilization on Silicon via Electrografting from Diazonium Salt Solutions. ACS Applied Materials & Interfaces 2(4): 1184-1190. http://dx.doi.org/10.1021/am100020a.

For scholarship opportunities please follow this link.

Dr Paul Gaynor

I currently have a few main areas of research interest that have projects available: Biomedical electronics, alternative electric power generation technology, and small-scale electric vehicles.

Note: If you have any of your own research project ideas in the general areas of biological electric field applications, alternative electric power generation, or power electronics applications (including electric vehicles), then let me know and we'll talk about the possibilities.

The biomedical research is based mainly around medical therapy/treatment uses of electric fields (as opposed to the more common diagnostic uses of electromagnetic fields - EEG, MRI, impedance tomography, etc). These uses cover important areas such as cancer chemotherapy, gene therapy, electro-surgery, liquid disinfection, and modern cloning.

Presently, the alternative electric power generation technology research I have been focusing on is low temperature differential Stirling engine based. New Zealand (along with many other countries) has a vast low temperature (sub 100°C) geothermal resource that could be tapped for the purposes of electric power generation. To be viable though, the technology must be relatively low cost and reliable. Stirling engines may provide one solution. In tandem with this research is the need for development of appropriate power electronic converters.

The small-scale electric vehicle research deals mainly with systems integration to create fully-functional electric vehicles that include smart battery charging and battery management.

Biomedical Electronics

Electrical Cell Movement and Alignment using Micro/Nano–scopic Electrode Systems (ME or PhD Project)

Nonlinear AC electric fields can be used to physically move cells. This effect is to be optimized for the purposes of cell movement in modern biomedical applications. The project requires a student with an interest in biological systems and is confident with manual skills. The project will be carried out in collaboration with scientists from AgResearch.

Bio-feedback Swallowing Rehabilitation (ME Project)

This project involves the design, building and testing of both electronics hardware and software to carry out biofeedback-based swallowing rehabilitation. Specifically, the system needs to be developed such that a smartphone app can be used to wirelessly link to the electronics involved with swallowing sensing and display biofeedback information in real time. This project is being carried out in collaboration with the Communication Disorders Department and the New Zealand Brain Research Institute.

High Voltage Liquid Disinfection System (ME Project)

Further development of a high-voltage method for liquid disinfection is required. This is a highly practical and hands-on project where stuff actually gets built and tested. The development is mainly around design that reduces power consumption and increases kill-rates. The project requires a practically-minded student with a desire to play around with some power. This project is being carried out in partnership with PowerHouse Ventures Ltd.

Integrated Electrically-Mediated Cancer Therapy System (ME or PhD Project)

Research is being carried out on the creation of high voltage apparatus for combined electric field pulsing and heating for a new multi-modal cancer therapy process. This apparatus will need to be integrated into a system that is appropriate for application to clinical trials. This project is being carried out in collaboration with researchers from both Christchurch and Dunedin Hospitals.

Pulse generator for cancer therapy

Electric Vehicles

Electric Scooter for Urban Commuting (ME Project)

This project involves the integration of a 200W hub-mounted brushless DC motor with a controller, batteries, and scooter superstructure. Additionally, a smart battery charging and management system will need to be developed so that battery life is maximised (as much as practically possible). A motor, controller, and batteries have already been acquired for use in this project.

Versatile 2-Person Compact Electric Vehicle (ME Project)

This project involves the integration of a 10kW brushless DC motor with a controller, batteries, and a novel superstructure capable of accommodating two people. There is some flexibility in this project as to the form of the superstructure. Additionally, a smart battery charging and management system will need to be developed so that battery life is maximised (as much as practically possible). A motor, controller, and batteries have already been acquired for use in this project.

Brushless DC motor for Compact Electric Vehicle

Stirling Engine Power Generation

Low Temperature Differential Electrically-Controlled Stirling Engine (ME or PhD Project)

This project is highly practical and quite mechanical, requiring the design, construction and control of a low temperature differential Stirling engine to efficiently output around 1kW of electrical power. A great deal of the mechanical superstructure has been built in a previous Masters project, but there is scope for some redesign and fabrication. A significant amount of electronics is involved with the sensing of pressure, temperature, and position, and the control of the engine and load characteristics.

Low temperature Stirling Engine for electric power generation

Grid-tie Power Inverter (ME Project)

There is a need to design a low-cost single-phase power inverter that can be used by those with small amounts of power generation capacity (nominally 500W), who wish to connect to their own household mains power supply. This is a highly hands-on power electronics project that will result in a skill base and knowledge many employers will find very attractive.

Low cost Grid-tie Inverter

Professor Neville Watson

Power Quality in Electrical Networks

Power Quality has been a major area of research for our group here over many years. There are two sides to this, the first is the performance of the electrical devices (both generation and loads) the second is the performance and characteristics of the electrical network itself and what it can withstand. The steps to be taken on both sides involve characterization, development of suitable models and the investigation of possible mitigation methods for the power quality issues.

Watson N.R. and Arrillaga J., “Power Systems ElectroMagnetic Transients Simulation”, IEE Books 2003.

Arrillaga J. and Watson N.R. “Power System Harmonics”, 2nd Edition, John Wiley & Sons 2003.

Arrillaga J., Smith B.C., Watson N.R. and Wood A.R., “Power System Harmonic Analysis”, John Wiley & Sons 1997.

Arrillaga J., Chen S. and Watson N.R., “Power System Quality Assessment”, John Wiley & Sons 2000.

Transient State Estimation (ME/PhD Project)

The concept of a new technique for Transient State Estimation, based on the well know numerical integrator substitution method, was demonstrated in 2008 on a small single-phase system. This is an exciting new technique and the potential needs to be explored. This is an improvement on the previous Transient State Estimation algorithm which used a state-variable. A more comprehensive three-phase version needs developing and the performance with measurement noise and bad-data detection need to be investigated.

Yu K.C.C. and Watson N.R., “An Approximate Method for Transient State Estimation”, IEEE Transactions on Power Delivery, Volume: 22, No. 3, July 2007, pp 1680- 1687.

Yu. K.K.C. and Watson N.R., “Identification of Fault Locations using Transient State Estimation”, Proceedings of the International Power System Transient Conference (IPST 2005), Montreal (Canada), June 2005.

Harmonic Domain Modelling of Distribution Systems (ME/PhD Projects)

The Harmonic Domain has been developed for accurate modelling the interaction of non-linear loads, such as HVDC links and FACTS devices in transmission systems. With the large scale deployment of CFLs and heat-pumps as well as the use of embedded generation with inverter interfaces, the need to accurately model their interaction is important and the direct harmonic current injection technique is not adequate for this situation. This project aims at developing new models in the Harmonic Domain and benchmarking the use of Harmonic domain against direct harmonic current injection technique for distribution system modelling.

Electromagnetic Transients Simulation (ME/PhD Project)

Electromagnetic Transient Simulation is an important aspect of any engineering design, however, the results are only as good as the component models and algorithm used. This project is aimed at furthering the state of the art in simulation techniques and system representation. Two specific areas needing further research are:

A new Frequency-Adaptive version numerical integrator substitution method.
Use of root-matching method inside component model such as the UMEC transformer model.

Computer Analysis of Electrical Power Systems

Electrical Power System Simulator (ME Project)

Many programs have been developed to advance the modelling of power systems, however, they are normally very specific. The aim of this project is to develop the framework and auxiliary programs (such as Transmission Line and Cable parameter programs) so that other analysis can be easily plugged in and tested. This is to be a text based framework similar to LFH so that it is portable and long lasting.

Arrillaga J. and Watson N.R., “Computer Modelling of Electrical Power Systems”, 2nd Edition, John Wiley & Sons 2001.

Modelling of HVDC and FACTS Devices in Conventional Power System Analysis Programs (ME/PhD Projects)

Power-electronic controllers, such as HVDC links and FACTS devices at transmission level and Custom Power devices at distribution level, are rapidly being introduced into electrical power systems to overcome technical constraints. The characteristics of these systems as well as their impact on the system need to be investigated. Conventional power system analysis algorithms need to be revisited to ensure adequate representation of these new devices.

Modelling FACTS devices in power system analysis (e.g. Power-Flow and Fault studies).
Development of a new three-phase Power System simulator using the latest techniques (this may include the new Harmonic Domain algorithm).

Phase Domain Fault Analysis Program (ME Project)

Traditionally sequence components are used in Fault analysis programs. Modern computers can easily handle matrix equations without the need to resort to sequence components. The aim of this project is to assess the loss of accuracy due to using sequence transform by developing a phase-domain Fault analysis program and comparing this with the traditional sequence component based Fault analysis program.

Artificial Intelligence in Power Systems (ME Project)

Artificial Intelligence techniques are now filling the power system journals as people research ways of gainfully using these techniques in power systems. Power system optimisation and control are areas that have potential due to the complexity of modern power systems. Processing the vast amount of power system information is another task AI techniques are being used for. This project is to investigate then implement an AI technique to optimise the power system. The optimisation of the power system is very important due to the significant benefits that can be achieved. Conventional optimisation techniques have difficulties due to the many constraints and multiple minima points and discrete nature of some parameters (Tap-position of transformers). Another interesting area is the use of AI techniques to optimise the design of harmonic filters for a given application.

Dr Alan Wood

Asset Intelligence for Power Transformers

A research opportunity is available to develop and implement asset intelligence systems in the area of power transformers in electricity distribution networks. Power transformers are by and large the most expensive and most critical single component of an electrical distribution network. High replacement costs, lengthy lead times on materials and significant customer impacts make the management of power transformers vital.

Despite the presence of transformers in the electricity industry for more than a century, there are still many research gaps in optimising their maintenance and performance. Condition diagnostic methods (especially during load operation) can be improved, asset deterioration with age and loading can be further understood and Smart Grid technologies such as Dynamic Rating can be applied to optimise transformer operation. This research project will be part of a broader initiative to develop asset intelligence capabilities comprising mathematical models, algorithms, decision-support and control systems which enable significant enhancement of operational performance, reliability and longevity of various asset classes.

The notion of asset intelligence is an incipient, progressive and fast-moving field of endeavour to equip network assets (for electricity distribution in this case) with a variety of so-called 'smart devices and sensors' which capture vast quantities of operational and condition-related data, which then have to be processed, interpreted and converted into actionable information. This information then better informs decision making, especially relating to options for manual or automated control, as well as network maintenance, planning, design and investment.

The development and implementation of asset intelligence systems pose strong challenges and opportunities for the demonstration of strength in the areas of:

Conceptualisation and mathematical modelling / simulation
Innovativeness / lateral thinking
Engineering / technological prowess

The research project will form the basis of a PhD study programme, to be supervised jointly by University teaching staff as well as qualified experts in the host company, Unison Networks Limited (Unison). Unison is an electricity distributor that supplies over 100,000 consumers in the Hawkes Bay, Rotorua and Taupo regions. Unison is a progressive business, focused on growth and the delivery of a high quality service to its consumer base.

The ideal candidate is high achieving and technically focused, with a strong interest (ideally proven experience) in the development of mathematical models. You will have excellent communication skills and be able to work as part of a team or unsupervised, as the situation calls for. You will perform strongly under pressure and time constraints, with good attention to detail. You will have an unwavering commitment to academic excellence.

Qualifications / Experience desired:

Postgraduate qualification in applied mathematics, statistics, operations research, engineering or related field
Proven experience in the development of mathematical models in MATLAB

This position will be jointly remunerated by Unison and University sourced funding. It will be based alternately at the Unison main office in Hawkes Bay and the University campus.

Energy Storage-based Instantaneous Reserve – Rapid Generator Acceleration and Grid Connection for Frequency Support

IRL have a Government funded project investigating the viability of a fast start-up generator to provide instantaneous reserve for our electric power system. They have a novel energy storage proposal, which will initially be used to provide 100kW for about 15 minutes, with a very short start-up time. This proposal will contribute to the implementation of a more environmentally friendly electric power system, and involvement with it will lead to a good understanding of electric power grid issues, signal analysis methods, and control.

The project involves simulation and implementation of a fast generator control system. The system must control the acceleration of an alternator up to approximately synchronous speed, check phasing, and connect with the electric power grid, all in less than a second. This project would suit someone with an interest in control, electric power system issues, and who is attracted by the idea of putting together a functioning system as part of a small and highly motivated team.

The project is based partly at the University of Canterbury Electrical and Computer Engineering Dept, under the supervision of Dr Alan Wood, and partly at IRL in Wellington, under the supervision of Dr Chris Bumby. It comes with ME scholarship support.

GREEN Grid: Managing Renewable Energy in New Zealand

The EPECentre has recently been awarded a research contract to conduct in an investigation into the impact of an increasing penetration of renewable resources into our electric power transmission and distribution network. All sorts of issues are involved – including the characterization and management of variability of renewable generation, assessment of the value of energy storage, determination of value and practicality of demand side participation, effect of distributed generation on voltage profiles and power quality, etc. If you decide to join this project you will be part of a group that is working on modeling, control algorithms, optimization, and market structures. It is being undertaken in conjunction with the Universities of Auckland and Otago, and is likely to influence decision making related to renewable energy policy in New Zealand in the future. PhD

Fault Location on Ground Fault Neutralised Distribution Lines

Ground fault neutralisers are able to reduce ground fault short circuit currents on distribution lines to very low levels, insufficient to maintain an arc. This allows power to be maintained while the fault is present, and minimizes the likelihood of causing damage and/or starting a fire when a fault occurs. If regions where there is a high fire risk, or a high requirement for reliability, this is a very useful solution. However, the low fault currents and lack of damage can make the faults very difficult to locate for repair. Although there are several commercial methods for fault location, none are without problems. Recent work here has developed a method to extract information from the very short transient that occurs at the fault inception, that hold useful information about the fault location. The aim of this project is to incorporate and extend this method to a useful and practical fault location system.

Harmonic State Space Modeling in Modern Power Supply Networks

Modern power systems are becoming extremely complex, not least due to the number of sophisticated power flow controllers (HVdc links, STATCOMs etc) and power electronic loads. All these devices generate harmonics, but importantly, the frequency coupling process that results in harmonics also couple transient waveforms to a broad spectrum of frequencies. The coupling between these frequencies at different locations can close feedback loops that lead to instability at surprising frequencies. The harmonic state space poses many frequencies as stationary variables, and efficiently models their transient variation using straightforward linear system analysis techniques. We have developed models for the TCR, an HVdc converter, and a PWM based voltage source converter. The aim of this project is to cement these models into a single framework, establish methods for developing more models, and prove the importance of these interactions.

Dr Andrew Bainbridge-Smith

Computational Arithmetic, Signal Processing and Digital Logic (ME/PhD Projects)

Algorithmic and computational techniques are assessed by looking at three criteria: performance, resource requirements and energy efficiency. The first criterion is usually well understood, relating to how quickly a calculation can be performed and includes concepts such as computational bandwidth or throughput (e.g. number of samples processed per second). It is also reasonable well understood that to achieve higher processing performance more complex algorithms (usually) are required, which in turn require more processing resources. Finally, but sometimes overlooked, algorithmic performance and resource utility in turn impacts on the energy efficiency of a design.

Thus for any application we need to address and balance the relative importance of these three design criteria. For example in mobile computing, particularly in the communications domain, battery powered devices demand that we place great importance on the energy efficiency of our algorithms, whilst still achieving a minimum performance target.

Until relatively recently these three issues have been rolled together into a choice between various microprocessors. In this case the efficiency of the hardware is fixed and any gains must be made through software. This approach can, however, be rather crude as the hardware choice maybe poorly matched to the problem. The other widely considered option in this situation is the possibility of an ASIC (application-specific integrated circuit) if the volume of production warrants it. However programmable logic devices (FPGAs) now provide a viable third choice, with the flexibility of programmability and performance of custom hardware logic.

Projects in this area involve investigating novel computational techniques to be implemented on programmable logic (and possible ASIC). The intention is to quantify the algorithms against the three design criteria. For example, we have been looking at new adder designs using redundant number systems (Will Kamp, PhD Student) as addition is fundamental to most computational methods. This work in turn has given insight into multiplication and MAC design, also being worked upon. There is room to extend this work in the area of other fundamental computation arithmetic architectures such as CORDICs, division and comparison. Some work has also been done in the area of alternative number systems for floating point arithmetic, an area where again much work could be done.

This work is of interest to organisations such as the Wireless Research Centre (WRC) as it provides insight into the design choices for digital signal processing at the frontend of radio systems. The WRC as part of NZi3 may well be in position to fund applicants in this research area.

Design for Digital Logic Circuits (ME/PhD Projects)

This research work focuses on how designs can be implemented in digital logic circuits. I am interested in both general purpose applications, say in image processing, as well as specific designs such as those in the signal processing research described above. The problem looks at how abstract designs can be recorded and then automatically “compiled” into an implementation, i.e. it's all about computer language and compiler design where the target is not a microprocessor but a programmable device (FPGA). Of course solutions already exist, but the aim here is to incorporate some ideas from software engineering, particularly the work in Aspect Oriented Design, a successor to Object Oriented Design. The objective is about improving the efficiency of translating abstract design into realised implementation.

Enhanced Retinal Imaging (ME/PhD Project)

The burgeoning epidemic of diabetes in New Zealand (and western nations in general) threatens to overwhelm health budgets (as much as 20% in NZ) in terms of chronic effects. It is one of the leading causes of blindness. Its disease history is progressive over the long term; with respect to the diabetic eye this means that constant monitoring is the major component of the treatment regime. Monitoring involves taking photographs of the retina (light sensitive part of the eye) and looking for particular pathology in the images. Should significant retinopathy (pathology of the eye) be observed laser therapy maybe undertaken and monitoring increased. The engineering research problems to be addressed here include developing image processing techniques for automatic detection of diabetic retinopathies, techniques for automated assistive screening, image management processes and processes for tele-medicine to provide screening services to remote communities.

Another potential research area includes advanced optical techniques, based on adaptive optics and wavefront sensing, to produce very high resolution images of the retina. With such images we could address questions such as “can this lead to better understanding of ocular pathology?” The work also has implications in the design of retinal cameras and super- microscopes/binoculars.

Professor Phil Bones

Vocoder Intelligibility (ME Project)

Tait are currently designing a brand new range of products which conform to the Digital Mobile Radio (DMR) standard, and approximately 2 years away from developing new Phase II P25 products. Both DMR and P25 Phase II have a new state-of-the-art very-low-bit-rate Vocoder which allows significantly better spectrum usage compared to older standards such as P25 Phase I. However Tait has no control over the Vocoder as it is part of the two standards and the Vocoder is purchased as a separate component. The perceived speech quality with the Vocoder to date has been disappointing. Following a study into the deficiencies by the Communications Disorders Department, this project is to develop signal processing algorithms which will attempt to modify the speech before or after the Vocoder process. An FRST Technology Industry Fellowship (TIF) application is planned to support the student and project. Supervisors: Philip Bones, Alan Murray (Tait Electronics Ltd).

Medipix CT Image Reconstruction (ME/PhD Project)

A new computed tomography (CT) scanner is being built at UC for imaging laboratory animals and samples of excised human tissue. It employs a new imaging chip called "Medipix" which has special energy discriminating electronics built into each pixel. Specific objectives for the project are: 1) to establish how much scatter reduction is possible compared with other detectors that cannot separate out specific energies of X-ray photons; and 2) to establish the best form of reconstruction algorithm suited for small animals, excised breast tissue and large organ imaging. Supervisors: Philip Bones, Anthony Butler (ECE Postdoctoral Fellow), Richard Watts (Physics and Astronomy).

Real-time Correction of Motion Effects in Magnetic Resonance Imaging (PhD Project)

We are developing methods for detecting and correcting motion effects in magnetic resonance imaging (MRI). We have already developed, tested and published a new algorithm for successful detection and correction of motion disturbances with postprocessing (i.e. performing the correction after the scan is finished). This approach is limited to certain types of motion. We now seek to measure the motion of the region being imaged in real-time and alter the scan parameters dynamically to achieve an artifact-free image. This challenging project involves advanced algorithms and instrumentation. It would suit someone with an interest in signal processing, image processing and/or RF electronics. Supervisors: Philip Bones, Richard Watts (Physics and Astronomy), Julian Maclaren (University of Freiburg, Germany).

Signal Delay in Cascaded Multirate DSP Systems (ME/PhD Project)

Multirate methods offer excellent efficiency for many signal processing tasks implemented on DSP devices. While a lot has been written about the efficiency, less is known about the signal delay properties of multirate designs. Preliminary work by Phil Bones seems to indicate that signal delay can be quite severe in some situations. The project will study in detail a number of common multirate configurations and design a software tool which can be used to estimate performance, both in terms of computation and signal delay. At least one publication in a quality journal can be expected.

Dr Michael Hayes

Shallow-water Synthetic Aperture Sonar (ME/PhD Project)

The Acoustic Research Group in the ECE department has a long track record of innovative developments in synthetic aperture sonar (SAS) which is a technique to form optical-like images of the seafloor. But the field has now moved on to where most of these types of sonar are mounted on unmanned submarines something that is way beyond a university budget. However, what has not been tried (and so is completely new) is how to operate one of these sonars in extremely shallow water; say less than 2m in depth.

We have a superb natural laboratory in Lyttelton Harbour which has a 2m tidal range. The idea would be to lay out a test object field at low tide in some area behind Quail Island and then image the object field at high tide. This will enable us to compare the image obtained with the actual object field (this is known as getting ground-truth). What is also very exciting is that we have almost all the equipment we need to conduct this research.

There are some significant technical issues that need to be addressed. Just how does any side-scan sonar operate in such shallow waters? Does a synthetic aperture sonar have any advantages over a traditional side-scan sonar? (Co-supervised by Professor Peter Gough).

Multiple View Synthetic Aperture Sonar (ME/PhD Project)

The goal of the synthetic aperture project is to obtain high resolution images of the seafloor and to have fun in the process. Currently we have to tow the sonar towfish along a (nominally) straight track but ideally we would like to be able to perform arbitrary manoeuvres, say to circle a part of the seafloor of interest. The problem is how the multiple views are combined to achieve higher quality imagery. Algorithms would need to be developed to reconstruct images from arbitrary synthetic apertures and to combine the multiple views. This project would suit a student interested in signal/image processing.

PMultiple Receiver Synthetic Aperture Sonar Autofocusing (ME/PhD Project)

We are currently extending our high-resolution underwater imaging sonar to employ an array of multiple receivers so that we can image the seafloor at greater speeds. However, due to the unknown motion of the sonar with respect to the sea-floor, we need to develop and employ autofocusing algorithms to correct the data measured from the receiver array so that we can obtain diffraction-limited imagery. Techniques developed in this area would also be applicable to other fields such as medical imaging. This project would be of interest to someone with an interest in signal/image processing.

Multipath Rejection for Bathymetric Synthetic Aperture Sonar (ME/PhD Project)

The goal of this project is to develop image reconstruction algorithms to produce high resolution bathymetric (height) images of the seafloor. These can be used to produce a detailed 3-D model of the seafloor. One of the key problems to solve is the rejection of multipath echoes from the sea surface. A likely solution is the application of statistical signal processing techniques similar to those used to separate multipath with cellular radio. This project would be of interest to someone with an interest in signal/image processing.

Spotlight Synthetic Aperture Sonar (ME/PhD Project)

The new synthetic aperture sonar we are developing has provision for steering of the transmitted beam in real-time. This can be used to insonify a portion of the seafloor of interest to achieve a higher resolution. The goal of this project is to develop software to control the steering of the transmitted beam and to collect, store, process, and display the received echoes. The software would run on the computers inside the sonar towfish and on the towboat. This project would suit someone interested in real-time software, embedded system development, and signal processing. There is also scope for digital hardware development and VHDL programming. (Co-supervised by Professor Peter Gough).

System-on-chip Imaging Processing (ME/PhD Project)

Synthetic aperture sonar image reconstruction is computationally intensive and we are looking for a student to extend our research at implementing these algorithms on high performance FPGAs. (Co-supervised by Dr Andrew Bainbridge-Smith).

Synthetic Aperture Sonar Simulation (ME/PhD Project)

Over the past few years we have developed a sophisticated synthetic aperture sonar simulator that models scattering of sound from the seafloor. I am looking for a student to extend the simulator to more accurately model the propagation of sonar signals and to make the simulator easier to use. This project would suit a person interested in signal/image processing, computer graphics, and programming.

Acoustic Timber Inspection (ME/PhD Project)

There is a demand by foresters for non-destructive techniques to assess the strength and stability of timber in standing trees. One approach is to send acoustic signals along the tree stem and to measure the propagation characteristics. The goal of this project is to construct smart microprocessor-based accelerometer probes that can be daisy-chained together. Each probe would sample the signal from its accelerometer and transmit that digitised waveforms via a wireless to a PDA or PC for further processing. This project would suit a student interested in electronics and digital signal processing. (Co-supervised by Professor John Walker of the Forestry Department).

Acoustic Tomography for Tree Inspection (ME/PhD Project)

The goal of this project is to image the mechanical properties of the wood inside a tree through measurements of stress waves obtained from accelerometers inserted around a tree. This project would suit a student interested in signal/image processing. (Co-supervised by Professor John Walker of the Forestry Department).

Dr Yusuke Hioka

About Supervisor

My major research focus is audio/acoustic signal processing and its applications to the problems we face in the real world. My research philosophy is to seek a novel technology which is based on certain theoretical justifications but which can also contribute to solving existing practical problems that might yet be a dream for us. Students who love the nature of the signal processing but are also interested to see their innovation working to solve real world problems would be the most appropriate for my research projects. I encourage interested students to pop in to my office so that we can discuss more details of each project.

Project Description

Don't you feel reluctant to speak on a phone while you are in a public space or even at home with your family? You may feel uncomfortable because your conversation is heard by other people around you. That is one of the reasons why we need a telephone box for a public telephone (naturally the box is also meant to be protection for the telephone and user from wet weather).

My ultimate research goal is to build an “acoustic enclosure” which allows you to manipulate sounds around you to be emphasised or reduced. The concept of acoustic enclosure is similar to the telephone box; it shelters you from various interfering sounds around you that disturb your conversation, and it also keeps your privacy by confining your voice within the enclosure rather than reaching other people around. In addition to these, one would also need to confine the sound reproduced by loudspeakers if he/she uses a hands-free communicating device. There are several ME/PhD projects related to this ultimate goal. Some of them need to seek state-of-the-art signal processing algorithm, but others would need to cover more multi-disciplinary problems. Below is the list of projects currently available. Besides these I also have a few other collaborative projects in audio/acoustic signal processing with researchers in/outside NZ, so please come and see me to talk more!

Distance distinguishing microphone system (ME/PhD)

This project aims at picking up sounds generated by sources located only inside the acoustic enclosure. The detrimental aspects of picking up ambient sound are not only the disturbance to the conversation, but also the threat to your privacy as a result of disclosing your location/situation to the other person. This problem is especially prominent when people use a hands-free device due to the high sensitivity of the microphone used for such a device.

Although there have been various conventional techniques/devices that well separate sounds arriving from different directions (e.g. super-directivity microphones), most of them cannot distinguish the distance of sound sources. We aim at establishing a new signal processing algorithm that enables to separate sounds of sources located in different distances from the microphone.

Sound confinement within acoustic enclosure (PhD)

In this project we seek a technique to conceal the content of your conversation from someone around you. There would be various approaches to solve this problem; you would even make use of human's perceptual characteristics as well as signal processing techniques.

For example reverberation is known to be one of the factors responsible for degrading speech intelligibility; various researches have been conducted to retrieve speech intelligibility by reducing the reverberation (i.e. dereverberation). Such phenomenon could be exploited contrariwise: degrading the intelligibility of listeners to conceal the conversation. The approach chosen to attempt to reach the goal is open and you are more than welcome to bring your own thoughts/ideas to discuss with me.

Blind estimation of room acoustics parameters (ME/PhD)

Do you know how we quantify the degree of reverberation of a room? There are various important parameters that determine the acoustic characteristics of a room. Nevertheless estimates of these parameters are essential in some sound reproduction technologies that would contribute to realising the acoustic enclosure problem. The parameters used are generally calculated by measuring the room's impulse response (RIR), which requires special measurement tools. Therefore blind estimation techniques that can calculate the parameters from passive recording data (i.e. arbitrary sound data recorded in the room) are needed.

In this project we particularly focus on estimating two major acoustic parameters: i) reverberation time, and ii) direct-to-reverberation energy ratio, by using multiple microphones. The project will include inventing a novel model of sound recorded in a reverberant room, as well as seeking effective signal processing algorithms to estimate the parameters.

Recent related articles published by the supervisor:

Hioka, Y., Kobayashi, K., Furuya, K. and Kataoka, A. (2008) Enhancement of Sound Sources Located within a Particular Area Using a Pair of Small Microphone Arrays. IEICE Transactions on Fundamentals E91-A(2): 561-574. (copies available on request)

Hioka, Y., Furuya, K., Haneda, Y. and Kataoka, A. (2011) Improving power spectra estimation in 2-dimensional areas using number of active sound sources. IEICE Transactions on Fundamentals E94-A(1): 273-281. (copies available on request)

Hioka, Y., Niwa, K., Sakauchi, S., Furuya, K. and Haneda, Y. (2011) Estimating Direct-to-reverberant Energy Ratio Using D/R Spatial Correlation Matrix Model. IEEE Transactions on Audio, Speech, and Language Processing 19(8): 2374-2384.

Hioka, Y., Furuya, K., Niwa, K. and Haneda, Y. (2012) Estimation of Direct-to-Reverberation Energy Ratio Based On Isotropic and Homogeneous Propagation Model. Aachen, Germany: International Workshop on Acoustic Signal Enhancement, 4-6 Sep 2012.

Hioka, Y., Furuya, K., Kobayashi, K., Niwa, K. and Haneda, Y. (2013) Underdetermined Sound Source Separation Using Power Spectrum Density Estimated by Combination of Directivity Gain. IEEE Transactions on Audio, Speech and Language Processing. (in press: already available on IEEE Xplore)

Adjunct Assoc Prof Richard Jones

Richard is Director of the Christchurch Neurotechnology Research Programme (www.neurotech.org.nz) based at Van der Veer Institute for Parkinson's and Brain Research (www.vanderveer.org.nz) and a formal joint venture between Canterbury District Health Board (Medical Physics and Bioengineering, Neurology), University of Canterbury (Electrical and Computer Engineering, Psychology), and University of Otago, Christchurch (Medicine).

Several ME/PhD projects are on offer within our Lapse Research Programme. These will be of particular interest to students with strong interests and expertise in signal and/or image processing and keen to apply and improve their skills in a fascinating, albeit challenging, area of biomedical/neural engineering.

Lapses in responsiveness (‘lapses'), including microsleeps and lapses of sustained attention, disrupt performance completely from ~0.5–15 s and can result in injury or death, especially in the transport sector (pilots, air-traffic controllers, truck & car drivers, etc.) We are a world leader in lapse research in terms of the characterization and EEG-based detection of lapses. Despite this achievement, the detection – and, better still, prediction – of lapses has proven a difficult nut to crack, with our current level of detection still someway to go before being sufficient for lapse detection devices in the real-world. As part of our drive to improve this detection, we are undertaking studies involving simultaneous-fMRI+EEG to improve our understanding of the spatiotemporal dynamics of lapses in the brain and provide additional cues for detection algorithms. For example, we have collected continuous and simultaneous fMRI, multi-channel EEG, and video of eyes from 20 healthy non-sleep-deprived adults while performing a novel 2‑D visuomotor tracking task for 50 min in a 3T MRI scanner. This, together with other past and planned experimental studies, has provided and will continue to provide masses of valuable data and opportunities and needs in advanced signal and image processing.

Projects on offer are:

Automated estimation of tonic arousal/alertness from EEG (via spectral analysis, non-linear methods, machine learning, etc.).
Bayesian approaches to detection of lapses of responsiveness (Bayes Nets, Bayesian-trained neural networks, Monte Carlo techniques, particle filters, etc.).
Real-time detection and prediction of microsleeps by enhancement of deep electrical activity in the brain (ICA , beamformer, etc.).
Lapse detection: Building a working portable prototype (placement & attachment of electrodes, dry hair-penetrable electrodes, development of wireless electrodes, etc.).
Adaptive non-stationary auto-regressive models for enhanced accuracy and increased temporal resolution of detection of lapses from the EEG.
Multimodal approaches to lapse detection (EEG, videometrics of face/eyes, corrective movements, head movements, etc.)
Prediction techniques: Comparison and optimization of techniques for prediction of lapses (also applications in clinic-based driver assessment and outcome from mild traumatic brain damage). Will involve investigating, optimizing, and validating statistical modelling techniques such as discriminant analysis, logistic regression, partial-least-squares correlation, Bayesian, and various types of artificial neural networks.
Causality analysis of fMRI and EEG.
Integration of fMRI and EEG to achieve optimal information on spatiotemporal dynamics of lapses (including different types) in the brain.
Automated detection and classification of lapses of responsiveness in the laboratory (from tracking performance and video of eyes).
Real-time multi-modal lapse and drowsiness detector. Will involve construction and evaluation of a prototype head-mounted real-time lapse detector based primarily on features obtained from multi-channel EEG and video-metrics of the eyes.

**Recent Publications (pertinent)**

Poudel GR, Jones RD, Innes CRH, Watts R, Signal TL, Bones PJ (in press). fMRI correlates of behavioural microsleeps during a continuous visuomotor task. Proceedings of 31st Annual International Conference of IEEE Engineering in Medicine and Biology Society (EMBC 2009), Minneapolis, USA, 31, 4 pages.

Poudel GR, Jones RD, Innes CR, Bones PJ. (2008). Characteristics and EEG spectral dynamics of behavioural microsleeps in a mock-MRI scanner. (Abstract) NeuroImage, 41, Supp. 1., S59.

Poudel G, Jones R, Innes C, Davidson P, Watts R, Signal L, Bones P (2008). Increased multisensory activity during cued slow-eye-closure while performing a visuomotor tracking task: an fMRI study. (Abstract) Australasian Physical & Engineering Sciences in Medicine, 31, 488-489.

Poudel G, Jones R, Innes C (2008). A 2-D pursuit tracking task for behavioural detection of lapses (Abstract) Australasian Physical & Engineering Sciences in Medicine, 31, 528-529.

Poudel GR, Jones RD, Innes CRH, Davidson PR, Watts R, Bones PJ, Signal TL (2008). Functional-MRI correlates of cued slow-eye-closure and task non-responsiveness during visuomotor tracking. Proceedings of 30th Annual International Conference of IEEE Engineering in Medicine and Biology Society (EMBC 2008), Vancouver, Canada, 30, 4122-4125.

Peiris MTR, Jones RD, Davidson PR, Bones PJ (2008). Event-based detection of lapses of responsiveness. Proceedings of 30th Annual International Conference of IEEE Engineering in Medicine and Biology Society (EMBC 2008), Vancouver, Canada, 30, 4960-4963.

Van Hese P, Vanrumste B, Hallez H, Carroll GJ, Vonck K, Jones RD, Bones PJ, D'Asseler Y, Lemahieu I (2008). Detection of focal epileptiform events in the EEG by spatio-temporal dipole clustering. Clinical Neurophysiology, 119: 1756-1770.

Davidson PR, Jones RD, Peiris MTR (2007). EEG-based behavioral microsleep detection with high temporal resolution. IEEE Transactions on Biomedical Engineering, 54: 832-839.

Peiris MTR, Jones RD, Davidson PR, Carroll GJ, Bones PJ (2006). Frequent lapses of responsiveness during an extended visuomotor tracking task in non-sleep-deprived subjects. Journal of Sleep Research, 15, 291-300.

Jones RD (2006). Measurement of sensory‑motor control performance capacities: Tracking tasks. In: Bronzino JD (Ed). The Biomedical Engineering Handbook – Biomedical Engineering Fundamentals, 3rd Edition, CRC Press, Boca Raton, Florida, Chapter 77, 1-25.

Dr Allan McInnes

"How can we engineer the interactions within complex systems?"

Answering that question is the basic motivation underlying my research. Of course, that's quite a broad question, so at the moment I'm focusing on some smaller pieces of the problem. In particular, I'm looking at tools and techniques for engineering the interactions within pervasive computing systems, networked embedded systems, “cyber-physical” systems, and distributed control systems. I have several ME and PhD research projects in these areas, and I'm open to suggestions for other similar projects. I'm also open to projects in other areas, including embedded systems design, robotics, fault-tolerant or dependable systems design, concurrency theory, and practical applications of formal methods. I encourage interested students to stop by my office (A513) so that we can chat about potential projects and where they might lead.

Sensor Network Debugging Tools (One or more ME Projects)

The goal of this project is to develop a system for gathering and analysing debugging data from a deployed wireless sensor network. The idea here is that the way sensor nodes behave in isolation can be quite different from the way they behave when they're situated in a network (due to differences in the environment and interactions with other nodes). So we're interested in having tools for seeing what's really going on in the network. A good starting point would be to design a device that enables in-situ measurements of sensor node power consumption. Beyond that, there's plenty of work to be done on refining and extending the design: gathering actual field data to help determine what sort of measurements are useful, improving the sensor design, adding other kinds of measurement capabilities, developing software for analysing and visualising the collected data, and figuring out how to integrate the information we're collecting into a real-time network debugging system.

SciPySim – Parallel System Simulation (One or more ME Projects)

SciPySim [http://code.google.com/p/scipy-sim/] is a research-driven system simulation package built on top of the SciPy scientific computing platform. The design of SciPySim is intended to encourage parallelization of simulations by making each simulation block a separate thread, eliminating (or at least minimizing the use of) the global simulation clock. In principle, this should make parallelization easy. In practice, there are both research challenges (“can we maintain a coherent simulation in the absence of a global clock?”) and software engineering problems (“how can we move from a multi-threaded to a multi-process execution model?”) to be overcome.

SciPySim – Discrete-Event Simulation of Continuous Systems (ME or PhD Project)

SciPySim [http://code.google.com/p/scipy-sim/] is a research-driven system simulation package built on top of the SciPy scientific computing platform. One of the more interesting experimental features of SciPySim is a discrete-event numerical integration scheme based on ideas developed in the DEVS research community. This scheme is quite different than standard fixed-step or variable-step numerical integration schemes, such as those used by Matlab, and offers some interesting advantages over standard schemes: easy event-detection, well-bounded errors, variable time-steps without the need for rollback, and asynchronous operation of separate integrators. These features make discrete-event integration seem like a good candidate for large-scale parallel simulation of mixed continuous/event-driven systems (such as large embedded systems). However, there's been very little work on developing this style of numerical integration. Depending on the interests of the student, this project could involve implementation and evaluation of some more complex integration schemes than the one presently in SciPySim, or could extend into a deeper study of the development and application of discrete-event integration algorithms for large-scale simulation of mixed continuous/event-driven systems.

Event-Based Control (Several PhD Projects)

Event-based control is an alternative to traditional periodic digital control. An event-based system only samples and performs control actuation when significant events (such as threshold crossings) occur in the controlled system. Event-based control is relatively easy to implement, and has been used in a variety of real-world applications. It also has a number of advantages over periodic control: it only performs control actions when necessary, is useful in situations where control actions or communications costs are high, and can be less sensitive to timing jitter. These advantages make it a good candidate for use in networked and distributed control systems. However, there has been only a small amount of work on developing a theory for event-based control systems, and many open research questions remain.

Professor Rick Millane

My research interests are in image reconstruction algorithms: signal processing techniques that are used to reconstruct images from various kinds of data, and related problems. I am interested in any application area, but current projects focus on applications in molecular biology and remote sensing for the Earth and atmospheric sciences. I find that applying electrical engineering principles to solve problems in different scientific and technical disciplines to be particularly interesting and productive. These projects involve signal processing, physical and mathematical modelling and analysis, diffraction, and computational algorithm development. The skills you will develop are in demand in areas such as biological and medical imaging, information and image processing, remote sensing (optical, radar, sonar, lidar, etc), modelling, and scientific and technical software development.

To find out more about my research projects, as well as similar projects by other staff members, refer to the “Computational Imaging Group” page on the Department Website at
www.elec.canterbury.ac.nz/imaging.

Potential projects are as follows. Most are suitable for PhD projects, but some might be suitable for ME projects.

Reconstruction algorithms for data from x-ray free-electron lasers

X-ray free-electron lasers (XFELs) are the latest and greatest x-ray sources. At a cost of about US$300 million, they generate extraordinarily short and intense x-ray pulses that can be used to image extremely small particles. They produce terabytes of data in a single experiment and there are many signal and image processing challenges to reduce this data to images. We are working with an international team who are using the only currently operational XFEL, the Linac Coherent Light Source (LCLS), at Stanford in California on these problems. This is an exciting project at the forefront of technology for which I have James Cook Research Fellowship funding.

Using sailplane flight data for atmospheric studies

There are thousands of recreational sailplane flights every year, all over the world. Sailplanes frequently carry data loggers, and much of this data is uploaded to publically accessible archives. These databases contain an enormous amount of potentially useful information for the atmospheric sciences. All that is required is smart people to mine this data and extract useful information for meteorologists. We have already had some success with such an approach using special flights and working with pilots, flight engineers and meteorologists at NASA This work can be extended to the much larger database of recreational flights.

Iterative projection algorithms for image reconstruction and other problems

Iterative projection algorithms are a class of computational methods for solving inverse problems where the data are sparse and have to be supplemented by various constraints. The problems are often very high-dimensional and plagued by local minima, and these algorithms have significant ability to escape from local minima. We have successfully applied these algorithms to image reconstruction in biological x-ray crystallography, and there are opportunities to apply them to other interesting and important technical problems.

Image Processing and Analysis for Remote Sensing

We have had some success applying image processing and analysis techniques to LIDAR (light detection and ranging) data from gravel river beds in the South Island. There is potential for working with staff in Gateway Antarctica and Geology on using image analysis techniques to extract useful information from other remotely sensed data.

Sample Publications

J. Chen, J.C.H. Spence and R.P. Millane. Phase retrieval in nanocrystallography. In “Image Reconstruction from Incomplete Data VII,” P.J. Bones, M.A. Fiddy and R.P. Millane (Eds.), Proc. SPIE, Vol. 8500, 85000I/1-12, 2012.

R.P. Millane, G.D. Stirling, R.G. Brown, N. Zhang, V.L. Lo, E. Enevoldson and J.E. Murray. Estimating wind velocities in mountain lee waves using sailplane flight data. J. Atmos. Ocean. Techn. A, 147, 147-158 (2010).

N. Zhang, R.P. Millane, E. Enevoldson and J.E. Murray. Determining wind fields in mountain waves using sailplane flight data. In “Image Reconstruction from Incomplete Data VII,” P.J. Bones, M.A. Fiddy and R.P. Millane (Eds.), Proc. SPIE, Vol. 8500, 85000S/1-9, 2012.

V. Lo and R.P. Millane. Characteristics of iterative projection algorithms. In “Image Reconstruction from Incomplete Data VII,” P.J. Bones, M.A. Fiddy and R.P. Millane (Eds.), Proc. SPIE, Vol. 8500, 85000D/1-6, 2012.

V. Elser and R.P. Millane. Reconstruction of an object from its symmetry-averaged diffraction pattern. Acta Cryst., A64, 273-279 (2008).

C.H. Yoon, B. Bodvarsson, S. Klim, M. Morkebjerg, S. Mortensen, J. Chen, J.R. Maclaren, P.K. Luther, J.M. Squire, P.J. Bones and R.P. Millane. Determination of myosin filaments rotations in electron micrographs of muscle cross-sections. IEEE Trans. Image Process., 18, 831-839 (2009).

V.L. Lo and R.P. Millane. Determination of molecular envelopes from solvent contrast variation data. Acta Crystallogr., A65, 312-318 (2009).

R.P. Millane, M.I. Weir and G.M. Smart. Automated analysis of imbrication and flow direction in alluvial sediments using laser-scan data. J. Sediment. Res., 76, 1049-1055 (2006).

Dr Steve Weddell

The core of my research is signal processing. However, the applied areas are diverse and span across several disciplines. Machine learning is employed to solve a variety of Ill-posed inverse problems, from predicting solar wind, to estimating the distortion function caused by the effects of a turbulent atmosphere. However, machine learning is not restricted to prediction. Echo state networks and liquid state machines have been applied to a plethora of engineering and biological applications, respectively, to characterise the behaviour of systems. Hardware implementations are used to achieve dimensionality reduction and improve computational efficiency. The emerging research group, Computational Design and Adaptation, is focused on developing and applying technology to model and understand robust, continuous, learning systems.

Astronomical imaging

Atmospheric turbulence exists even under the best seeing conditions and results in distorted images of faint astronomical objects when viewed using optical, ground-based telescopes. However, images can be reconstructed using inverse methods such as deconvolution from wavefront sensing (DWFS). To achieve this, turbulence data are acquired from a bright star, typically within close proximity, i.e., the isoplanatic patch, of a faint astronomical science object. An optical wavefront sensor is used to convert wavefront phase to a Zernike polynomial series. Importantly, the resulting point spread function (PSF) representing this distortion is spatially variant over a wide field-of-view (FoV). The estimated wavefront or PSF is used to correct either the optical path using adaptive optics (AO) or the image using DWFS, respectively. My work combines artificial neural networks (ANNs) with tomographic projections of several bright stars over a wide FoV and estimates wavefront distortions outside the isoplanatic patch. Thus, ANNs are employed to predict spatiotemporal perturbations and this method can also be applied to general image processing.

Image from a Shack Hartmann optical wavefront sensor.

Simulated wavefront from a Shack Hartmann wavefront sensor.

Weddell, S.J. and Webb, R.Y. “Reservoir Computing for Prediction of the Spatially-Variant Point Spread Function. Selected Topics in Signal Processing, IEEE Journal of, Vol.2, No.5, 624-634, Oct. (2008).

Niv, E. and Weddell, S.J. A Comparative Study of Random Hidden Node Networks for Pattern Recognition”, Image and Vision Computing New Zealand (IVCNZ2011), Dec. (2011).

Lapse detection with recurrent neural networks

This work is being conducted with Professor Richard Jones from the New Zealand Brain Research Institute (NZBRI). The NZBRI is a world leader in lapse research, in terms of behavioural detection and characterization, EEG-based characterisation and detection, and investigation of the underlying mechanisms in the brain via simultaneous fMRI, EEG, and tracking eye movements. However, despite significant achievements of late, the accuracy of EEG-based detection of microsleeps is currently too low for real-time implementation. Thus, a combination of EEG and real-time eye monitoring has the potential to detect microsleeps, and, better still, predict their occurrence. Leveraging off epileptiform activity in the EEG using recurrent neural networks, an optimised, reservoir computer architecture is being developed to detect lapses in responsiveness.

Poudel G.R., Innes C.R.H., Bones P.J. and Jones R.D. The relationship between behavioural microsleeps, visuomotor performance and EEG theta. Proceedings of Annual International Conference of IEEE Engineering in Medicine and Biology Society. 2010;32:4452-5.

Example of a reservoir-based computing network. Examples of combined EEG and eye-tracking headsets.

Example EEG traces.

Representing wavefront aberrations over a circular aperture (ME/PhD Project)

Zernike polynomials have been used to describe wavefront aberrations over a circular aperture. However, the set of Zernike polynomials are suboptimal, i.e. the covariance matrix of their coefficients contains non-zero terms off the diagonal. This research will consider alternative modal expansions, such as the Karhunen-Loéve expansion, and investigate alternative representations using an artificial neural network to classify a basis set supporting uncorrelated coefficients.

Intelligent modules for an evolvable hardware system (ME/PhD Project)

An evolvable hardware system comprises a reconfigurable circuit that is self-modified by the application of a genetic algorithm. This research requires the construction of a set of inter-operational components comprising simple analogue and digital modules that incorporate additional sensory capabilities that can be used as the basis for an evolvable architecture. For example, a field programmable gate array (FPGA) can be used in conjunction with programmable analogue circuitry as the basis for an evolving architectural platform. The construction of both analogue and digital modules will be required to incorporate capabilities to initially self-repair and possibly evolve, through unsupervised learning. Currently, evolvable architectures utilise VLSI technology however the basis of this work will be a combination of FPGAs and discrete analogue components. The system will be used as a test-bed for the application of a suitable genetic algorithm.

Design and development of a low-cost image correction system for small to medium sized telescopes (ME/PhD Project)

Adaptive optics (AO) is a technology originally developed by the US defence force to dramatically improve the resolution of ground-based telescopes. This is achieved by modifying the optical path of a telescope in real-time. Since declassification of the technology in the late 80’s, most large telescopes now employ AO; with results that rival space telescopes in the near infrared spectrum. However, there is a considerable number of small to medium telescopes (≤1m diameter aperture) that have yet to be converted. One major restriction is the high cost of precision optics and electro-mechanical devices. This research is based on developing a low cost imaging system that can be used to correct images at a rate of 50 frames-per-second using a method known as deconvolution from wavefront sensing. This method does not correct the optical path but uses image processing to restore each image. However, this method does require fast image sensors and the use of semi-custom hardware to stream and process image data to achieve real-time performance.

Evolutionary computer architecture (ME Project)

The instruction set architecture (ISA) of most modern computers is static. What is required is an evolutionary computer architecture that learns to adapt to the demands of CPU load and/or the types of algorithms that employ specific on-chip resources. A self-modifying ISA computer would have the potential to be whatever you want it to be, from an ATMega8 to an i7, depending on the application program on hand (or in memory). Such modifications can be incorporated by the application of an on-chip genetic algorithm.

Cascaded spatial light modulators for optical wavefront phase generation and correction (ME Project)

Research in the generation and correction of optical wavefront phase perturbations is required. Currently the Optical Laboratory supports a turbulence generator to generate phase perturbations for related work in adaptive optics. However, an alternative technology employs the super-twist quality of liquid crystal displays to alter optical wavefront phase. Projecting a laser through LCD material can produce wavefront maps and phase screens, the results of which can be imaged using polarised filters on high-speed CCD cameras. The employment of multiple, cascaded LCDs would allow emulation of multi-conjugate adaptive optical systems in the laboratory.

Mobile Power Efficient Auditory Speech Encoding (ME project)

Ultra-low power, small mobile devices need a mechanism to transmit information to users. Implement a learnable, pleasant, and moderately expressive encoding of human speech on a mobile platform such that information can be unobtrusively transmitted using low power sound generation on simple processors rather than presented through power and size inefficient displays.

University of Canterbury

Electrical and Computer Engineering

Study

For

About

Research Groups

Research Centres

Postgraduate Research Projects 2013

Research Areas and Staff Members Research Projects

Communications

Nanotechnology and Solid State Devices

Power Systems and Power Electronics

Signal and Image Processing

Dr Kim Eccleston

Substrate Integrated Waveguide (both ME and PhD candidates)

Integration of Active Devices with Electromagnetic Structures (both ME and PhD candidates)

Microwave Metamaterials (both ME and PhD candidates)

Efficient Microwave Power Amplifiers (most suitable for ME candidates)

Selected Publications:

Assoc Prof Philippa Martin

COMMUNICATION NETWORKS (Co-supervised by Dr Andreas Willig, CSSE Department)

Analysis and Systems Design for Systems with Multiple Hops, Users and Relays

Design of Advanced ARQ Schemes

LARGE COMMUNICATION SYSTEMS (Co-supervised by Assoc Prof Peter Smith)

COGNITIVE RADIO SYSTEMS (Co-supervised by Assoc Prof Peter Smith)

MULTIPLE ANTENNA SYSTEMS (Co-supervised by Professor Des Taylor)

Multiuser MIMO

High Rate Space-Time Codes with Manageable Decoding Complexity

Coded Modulation for Space-Time Systems

Adaptive Space-Time Code Design

ERROR CONTROL CODING (Co-supervised by Professor Des Taylor)

ULTRA-WIDEBAND COMMUNICATIONS (Co-supervised by Professor Des Taylor)

Recent International Journal Publications

Recent International Conference Publications

Recent Thesis Completions

Professor Peter Smith

Publications

Professor Desmond Taylor

Cognitive Radio Systems

MIMO Systems using Multi-Amplitude Minimum Shift Keying (MAMSK)

Estimator Detector Receivers for MIMO

Capacity Analysis for Cooperative Radio Systems

Multi-User Detection Algorithms

Combined Decoding and Equalization Studies

Assoc Prof Maan Alkaisi

Nanoimprint Lithography of Textured Surfaces for Photovoltaic Applications (Nanotechnology) (PhD Project)

Fabrication of Thin Film Solar Cells on Pre-textured Substrates

Development of Lab on Chip for Single Cell Analysis and Imaging (Bionanotechnology, PhD Project)

Publications

Chapters in Books

Recent Refereed Publications

Dr Martin Allen

UV Photodiodes (ME/PhD Projects)

Radiation Resilient, High Temperature Devices (ME/PhD Projects)

Related Publications

Related Conference Presentations

Dr Volker Nock

Control and Measurement of Oxygen in Microfluidic Devices

Selected Publications

Force Pattern Characterization in Moving Micro-Organisms

Selected Publications

Self-Propelling, Coalescing Droplets

Selected Publications

Surface Modifications and Cell-Substrate Interactions

Selected Publications

Dr Paul Gaynor

Electrical Cell Movement and Alignment using Micro/Nano–scopic Electrode Systems (ME or PhD Project)

Bio-feedback Swallowing Rehabilitation (ME Project)

High Voltage Liquid Disinfection System (ME Project)

Integrated Electrically-Mediated Cancer Therapy System (ME or PhD Project)

Electric Scooter for Urban Commuting (ME Project)

Versatile 2-Person Compact Electric Vehicle (ME Project)

Low Temperature Differential Electrically-Controlled Stirling Engine (ME or PhD Project)

Grid-tie Power Inverter (ME Project)

Professor Neville Watson

Transient State Estimation (ME/PhD Project)

Harmonic Domain Modelling of Distribution Systems (ME/PhD Projects)

Electromagnetic Transients Simulation (ME/PhD Project)

Electrical Power System Simulator (ME Project)

Modelling of HVDC and FACTS Devices in Conventional Power System Analysis Programs (ME/PhD Projects)

**Recent Publications (pertinent)**