Type-2 Fuzzy Logic: Managing uncertainty and imprecision in telecoms and finance
Submitting Institution
University of EssexUnit of Assessment
Computer Science and InformaticsSummary Impact Type
TechnologicalResearch Subject Area(s)
Mathematical Sciences: Applied Mathematics
Information and Computing Sciences: Computation Theory and Mathematics, Information Systems
Summary of the impact
Professor Hani Hagras' research into type-2 Fuzzy Logic Controllers
(FLCs) underpins novel control systems which avoid the drawbacks and
shortcomings of the type-1 FLCs used in numerous real world applications.
Type-2 FLCs, developed at Essex, enable challenging applications to be
realised and managed with better accuracy and robustness. Such
applications include:
- Telecommunications:
- British Telecom employ type-2 FLCs for capacity planning, improving
the efficiency of their workforce deployment
- Finance:
- LogicalGlue Ltd applied type-2 FLCs to develop a group
decision-making system which outperforms existing commercial
counterparts
- Discovery Investing Scoreboard Inc. use type-2 FLCs to identify
early stage investment opportunities
Underpinning research
Since the invention of fuzzy logic more than four decades ago, great
progress has been achieved using type-1 FLCs, which are applied to a huge
number of real world applications, including domestic appliances and
industrial automation. However, it became apparent that type-1 FLCs cannot
fully handle the numerous uncertainties encountered in real world
environments, as type-1 FLCs employ `crisp' type-1 fuzzy sets. As a
result, since 2000 there has been renewed interest in systems which make
use of type-2 fuzzy logic (based on the work of various researchers in the
USA (such as Professor Jerry Mendel) and Europe (such as Professor Robert
John)). This has stemmed from the fact that type-2 fuzzy sets are
three-dimensional and have higher degrees of freedom, meaning that they
can avoid the drawbacks of type-1 FLCs. However, before 2002, type-2 fuzzy
logic systems (FLSs) were deemed too computationally expensive to be
applied to real world control applications.
In 2002, Hagras (then as Lecturer) presented real-time type-2 FLCs
capable of handling the high levels of uncertainty experienced in real
world applications. Since 2002, as Senior Lecturer and Professor, his
subsequent research has led to the realisation of theoretical and
practical innovations that can avoid the computational overheads
previously associated with type-2 FLSs, allowing type-2 FLCs to operate in
real-time. His research has involved the introduction of hierarchical
type-2 FLCs (Hagras, 2004), hardware, including type-2 fuzzy co-processors
(Wagner and Hagras, 2010), as well as the development of new theoretical
algorithms to avoid computational overhead (Lynch et al., 2006). An
additional focus has been the development of learning techniques to enable
the optimal design of type-2 FLCs, leading to novel neuro and genetic
type-2 FLCs (Hagras et al., 2007).
Finally, Hagras' research has also generated real-time general type-2
FLCs, thus unleashing the full power of type-2 FLCs. A key result of these
efforts was the realisation of the first type-2 FLC for industrial use,
which was applied to the speed control of marine engines manufactured by
MAN B&W Ltd (Lynch et al., 2006). Building on this achievement, Hagras
and his students continued their efforts towards effective realisation of
many of the first real world type-2 FLC applications (Lynch et al., 2006;
Hagras et al., 2007; Jammeh et al., 2009; Lee et al., 2010). These efforts
have resulted in the more universal acceptance of type-2 FLCs, the
benefits that they have to offer, and their subsequent exploitation in a
global and diverse range of sectors and applications.
References to the research
Hagras, H. (2004) A hierarchical type-2 fuzzy logic control architecture
for autonomous mobile robots, IEEE Transactions on Fuzzy Systems,
12, 524-539. (469 citations — November 2013) DOI:10.1109/TFUZZ.2004.832538
This paper was awarded, by IEEE Computational Intelligence Society
(CIS), the 2004 IEEE Transactions on Fuzzy Systems Outstanding Paper
Award. The award citation states: "The paper has presented major
original theoretical advances to the field of type-2 fuzzy systems. The
paper has also presented ground breaking results which showed for the
first time how the type-2 FLC can handle the uncertainties in changing
and dynamic unstructured environments. This paper will have a major
impact on advancing the fuzzy control research and its application".
Lynch, C., H. Hagras and V. Callaghan (2006) Using uncertainty bounds in
the design of an embedded real-time type-2 neuro-fuzzy speed controller
for marine diesel engines, Proceedings of IEEE International
Conference on Fuzzy Systems, Vancouver, Canada, pp.1446-1453. (62
citations — November 2013) DOI:10.1109/FUZZY.2006.1681899
Hagras, H., F. Doctor, A. Lopez and V. Callaghan (2007) An incremental
adaptive life long learning approach for type-2 fuzzy embedded agents in
ambient intelligent environments, IEEE Transactions on Fuzzy Systems,
15, 41-55. (77 citations — November 2013) DOI:10.1109/TFUZZ.2006.889758
Jammeh, E., M. Fleury, C. Wagner, H. Hagras and M. Ghanbari (2009)
Interval type-2 fuzzy logic congestion control for video streaming across
IP networks, IEEE Transactions on Fuzzy Systems, 17, 1123-1142.
(58 citations — November 2013) DOI:10.1109/TFUZZ.2009.2023325
Lee, C., M. Wang and H. Hagras (2010) A type-2 fuzzy ontology and its
application to personal diabetic diet recommendation, IEEE
Transactions on Fuzzy Systems, 18, 374-395. (77 citations — November
2013) DOI:10.1109/TFUZZ.2010.2042454
Wagner, C. and H. Hagras (2010) Towards general type-2 fuzzy logic
systems based on zSlices, IEEE Transactions on Fuzzy Systems, 18,
637-660. (105 citations — November 2013) DOI:10.1109/TFUZZ.2010.2045386
This paper was awarded, by IEEE Computational Intelligence Society
(CIS), the 2010 IEEE Transactions on Fuzzy Systems Outstanding Paper
Award. The award citation states: "This seminal paper allowed
breakthroughs to the theory and applications of type-2 FLCs where the
paper presented a complete "modern" approach to design and realize
general type-2 FLCs based on zSlices type-2 fuzzy sets".
Research funding:
European Commission:
Callaghan and Hagras, eGadgets, Jan `01 — Jan `04, £237,000
Callaghan, Colley and Hagras, SOCIAL: Self-Organised Societies of
Connectionist Intelligent Agents capable of Learning, Jan `03 — May
`06, £286,761
Hagras, Colley, Fowler and Callaghan, ATRACO: Adaptive and Trusted
Ambient Technologies, Jan `08 - Jun `11, £542,782
Other sponsors
have included the ESRC, TSB (four projects totalling ~£800k), The Taiwan
National Science Council (three projects totalling ~£150k) as well as
sponsors from the private sector, including BT (five projects totalling
~£260k) and MAN B&W (~£56k).
Details of the impact
Many `real world' processes, both industrial and domestic, are affected
by high levels of uncertainty and imprecision. Fuzzy logic systems (FLSs)
laid the basis for a successful method to model vagueness, uncertainty and
imprecision. Type-2 FLCs, capable of real-time operation and which can
overcome the drawbacks of type-1 FLCs, developed and presented by Hagras
and his students, have enabled applications that were not previously
possible. The underpinning research sparked a strong interest from
industry where there is a need to develop intelligent systems which can
handle high uncertainty levels and deliver responses which avoid the
drawbacks of existing systems. As a result of the work of Hagras and his
students, type-2 FLCs have directly underpinned the realisation of impact
in a number of real world contexts.
Telecommunications:
British Telecom (BT): BT employs a large mobile workforce, in
which engineers cover particular geographic areas and are assigned jobs in
response to customer needs. Given the size of this workforce and the
complexities of its deployment, ensuring the most efficient use of skills
and resources is extremely important. It was recognised that systems
developed at Essex would be ideally suited for handling the level of
uncertainty associated with this task and thus, under a research contract
beginning in 2010, the project `Distributed and Fuzzy Resource
Planning' was established [see corroborating source 1].
The project used type-2 FLCs, developed at Essex, to accommodate the
inherent uncertainties and imprecision associated with workforce capacity
planning; for example, in intelligently deploying engineers to cover
overlaps in coverage encountered at multiple adjoining geographic areas.
Fuzzy boundaries and shifts were created, and engineers were matched to
multiple areas, to enable optimum and dynamic allocation of skills and
resources. In 2011, a newly developed system, based on the insight of this
research, demonstrated a considerable saving of engineers' time. This
improved efficiency has resulted in a greater throughput of job completion
for customers. In a letter of support, the Head of Resource Management
Technologies Research at BT acknowledges the importance and usefulness of
this research. In recognition of its efficacy, BT intends to apply the
system for managing its workforce deployment throughout the UK [2].
Financial applications:
LogicalGlue Ltd: In 2006, a Knowledge Transfer Partnership was
undertaken between the University of Essex and Sanctuary Personnel Ltd,
which resulted in the formation of LogicalGlue Ltd in 2009. A type-2 FLC
was deployed by LogicalGlue to develop a group decision-making system for
various domains. Within the financial domain, the fuzzy system has been
used for credit scoring and has consistently outperformed existing
commercial counterparts. During independent technical trials with a
leading credit rating agency, LogicalGlue's website reports how the
company's system demonstrated an 11% uplift in spotting defaults in credit
card data when compared to leading statistical regression systems [3]. In
a letter of support, LogicalGlue's CEO goes on to explain: "As well as the
capability of these implementations to handle uncertainty, their
`white-box' transparency also meant that the reasoning behind given
decisions could be understood; it enabled the system to provide an
explanation of its operation, in a user-friendly, easy to interpret and
language-based system" [4].
This work was awarded the 2009 Lord Stafford Award for Achievement in
Innovation for East of England. The award citation stated: "...the result
is a product that is not only benefiting IPFour [the parent company of
Sanctuary Personnel Ltd] but could also have a much further reach" [5]. In
2011 the project was also named the best KTP in London and the East region
[6] and listed as a finalist in the TSB's `Best of the Best' awards [7,
see page 6], at a time when approximately 1000 other projects were in
progress. Two further KTPs (entitled `Developing Intelligent Data
Integration and Visualisation Tools' (January 2010 - December 2013,
£211,266) and `Developing Intelligent Adaptive Systems for Process
Control and Production Optimisation in the Oil Refining Industries'
(August 2010 - August 2013, £197,266)) have been awarded to the company
and the University, to continue knowledge transfer projects.
Discovery Investing Scoreboard Inc.: Since 2010, USA-based
Discovery Investing Scoreboard Inc. has used Hagras' research to develop a
free online service for evaluating the investment potential of companies.
It was recognised, in particular, that micro- or small-capitalisation
companies are often not established enough to be able to demonstrate the
necessary data, references or proven assets that might be required to
measure suitability for investment via traditional methods of investment
analysis. However, in many cases, it is these small or early stage
companies in which many of the most prudent investments can be made,
before they have the opportunity to fully exploit their potential for
growth. The type-2 FLSs employed by Discovery Investing enable handling of
encountered linguistic uncertainties and can be used to produce a score of
a company's `discovery potential', associated with a given level of
imprecision. The company's CEO believes that the system is the first
commercial product to use interval type-2 fuzzy logic in a language-based
computing implementation for application to the digital economy. In a
letter of support he explains how "The system has been in use for one and
one-half years and is having a deep impact for evaluating businesses in
the USA and in other emerging and existing companies all over the world. I
am delighted to acknowledge the value of the insight which Professor
Hagras' research provided in this instance" [8].
Sources to corroborate the impact
[All sources saved on file with HEI, available on request]
[1] Agreement between British Telecommunications plc. and
University of Essex (2010), relating to "Distributed and Fuzzy Resource
Planning"
[2] Head of Resource Management Technologies Research, BT
[3] LogicalGlue Ltd About Us. Award-Winning Advanced Business
Analytics Software [online] Available from: http://www.logicalglue.com/about-us/
[Accessed 9 July 2013]
[4] CEO, LogicalGlue Ltd
[5] Praxis Unico, 2009. Leading university research wins
prestigious award [online] Available from:
http://www.praxisunico.org.uk/news/member-detail.asp?ItemID=234
[Accessed 9 July 2013]
[6] Email from the Head of Knowledge Exchange, Technology Strategy
Board, sent to the HEI in August 2011
[7] Technology Strategy Board, 2011. Best of the Best. KTP
Awards 2011 [pdf] Available from:
http://www.ktponline.org.uk/assets/2011/special/2011AwardsBestOfBest.pdf
[Accessed 9 July 2013]
[8] CEO, Discovery Investing Scoreboard Inc.