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Senior Research Fellow
Principal of Furness College
Director of Studies (ENV degrees Part
II)
LEC Natural Sciences Tutor
LEC Environmental Mathematics Tutor
Academic interests:
For more details and publications list please see my University research page
Info:
UNEP Air Report:
Dynamic Harmonic Regression (DHR) method, developed by our research group and implemented in Captain Toolbox for Matlab, features in the Guidance Section of the UNEP Air Report as a recommended research tool for investigation of trends and for seasonal adjustment. This recommendation follows a successful recently published application of DHR in analysis of fate and dynamics of atmospheric POPs (Persistent Organic Pollutants) - a joint project with Sara Massey (NERC funded Ph.D. Student) and Crispin Halsall (see Recent Publications).
See a simplified example of DHR analysis here showing how easy it is to obtain seasonally adjusted data and a statistical assessment of change, both long term and instantaneous.
New Release of Captain Toolbox
New release of Captain Toolbox (version 7.0, December 2009 with subsequent minor updates and bug-fixes) includes new and improved estimation procedures for continuous and discrete transfer function identification and estimation. The new procedures for continuous time estimation will have significant impact in estimation of complex and stiff systems, which combine very fast and very slow dynamic modes as well as full ARMA (Box-Jenkins) noise models.
Publications:
Recent (2007-2011)
Walsh, R.P.D., Bidin, K., Blake, W.H., Chappell, N.A.,
Clarke, M.A., Douglas, I., Ghazali, R., Sayer, A.M., Suhaimi, J.,
Tych, W. and Annammala, K.V. (2011) Longer-term responses of rainforest
erosional systems at different spatial scales to selective logging
and climatic change. Phil. Trans. R. Soc. Lond. B., (in submission)
Tych, W. and P. C. Young (2011) A matlab software framework for dynamic model emulation., Environmental Modelling & Software (in reviews)
Chappell N.A., Tych W. (2011) Identifying step changes in streamflow and evapo-transpiration records due to forest cover change, Hydrological Processes (in print)
Tych W., Sadeghi J. ,
Smith P.J., Chotai A., Taylor C.J. (2011) Multi-State-Dependent parameter model
identification and estimation, In L. Wang, H. Garnier, and A. J. Jakeman (Eds.), System Identification, Environmetric Modelling and Control, Berlin. Springer-Verlag
Taylor C.J., Chotai A., Tych W. (2011) Linear and Nonlinear Non–Minimal State Space Control System Design, In L. Wang, H. Garnier, and A. J. Jakeman (Eds.), System Identification, Environmetric Modelling and Control, Berlin. Springer-Verlag
Sadeghi J., Tych W., Chotai A., Young P.C. (2010) Multi-state dependent parameter model
identification and estimation for nonlinear
dynamic systems, Electronics Letters, 46(18) *
Chappell N.A.,
Discenza A. R., Tych W., Whittaker J., Bidin K. (2009) Simulating hourly rainfall
occurrence within an equatorial rainforest, Borneo Island, Hydrological Sciences–Journal–des
Sciences Hydrologiques, 54(3) *
Smith, P.J., Hughes,
D., Beven K.J., Cross P., Tych W., Coulson G., Blair G., (2009) Provision of
site specific flood warnings using wireless sensor networks, Meteorol.
Appl. 16: 57–64 also
published in: Samuels, P. and Huntingdon, S. and Allsop, W.
and Harrop, J., (eds.) Flood risk management :
research and practice. CRC Press, London. ISBN 9780415485074
S. Becker, C. J. Halsall,
W. Tych, R. Kallenborn, M. Schlabach, and S. Manø, (2009), Changing sources and environmental factors reduce
the rates of decline of organochlorine pesticides in the Arctic Atmosphere, Atmos.
Chem. Phys. Discuss.,
9, 515–540 *
Sochaczewski,
L; Davison, W; Tych, W; Zhang, H, (2009), Understanding small-scale features in DGT measurements in sediments,
Environmental Chemistry, 6(6)
477–485
Hughes
D., Daude M., Coulson G., Blair G., Beven K., Smith P., Tych W., (2008)
Managing Heterogeneous Data Flows in Wireless Sensor Networks Using a ‘Split
Personality’ Mote Platform, in the proceedings of the 2nd International Workshop on SensorWebs, Databases and Mining in
Networked Sensing Systems (SWDMNSS 2008), Turku, Finland, July 2008.
Smith
P., Beven K., Tych W., Hughes D., Blair G., (2008) The Provision of Site
Specific Flood Warnings Using Wireless Sensor Networks., in the proceedings of
the European Conference on Flood Risk
Management (FloodRisk’08), Oxford, UK, September 2008.
Sochaczewski,
L; Stockdale, A; Davison, W; Tych, W; Zhang, H, (2008), A three-dimensional
reactive transport model for sediments, incorporating microniches, Environmental Chemistry, 5 (3):
218-225
Becker,
S; Halsall, CJ; Tych, W; Kallenborn, R; Su, Y; Hung, H (2008), Long-term trends
in atmospheric concentrations of alpha- and gamma-HCH in the Arctic provide
insight into the effects of legislation and climatic fluctuations on
contaminant levels, Atmospheric
Environment, 42 (35):8225-8233 2008
*
N.J.
Lehto, Ł. Sochaczewski, W. Davison, W. Tych, H. Zhang, (2008) Quantitative
assessment of soil parameter (KD
and TC) estimation using
DGT measurements and the 2D DIFS model, Chemosphere, Volume
71, Issue 4, March 2008, Pages 795-801
Solera-Garcia M.A., Chappell N, Tych W. (2007), Identification of Diurnal, Seasonal and Inter-Annual Variability Across SE Asian Field Observations of key Water Cycle Variables: Rainfall, net Radiation, Total Evaporation and River Discharge, AGU, 88(52)
Chappell N.A.C, Tych W., Bonnell
M., 2007, Development
of the forSIM
model to quantify positive and negative hydrological impacts of tropical
reforestation, Forest Ecology and Management, Volume 251, Issues 1-2, 30
October 2007, Pages 52-64
Łukasz Sochaczewski, Włodek Tych, Bill Davison, Hao Zhang, 2007, 2D DGT induced fluxes in sediments and soils (2D DIFS), Environmental Modelling & Software, 22, 1, 14-23
C.James
Taylor, Diego J. Pedregal,
Peter C. Young, Wlodek Tych: (2007) Environmental time series analysis and
forecasting with the Captain toolbox. Environmental
Modelling and Software 22(6): 797-814
Most cited (with citation indices)
Current and Recent
Projects
The general thread in
these apparently wide-ranging application areas is modelling of complex natural
dynamic systems while not denying the underlying uncertainties; and the effect
of scale (both spatial and temporal) on the modelling process and model
structure. The other fundamental element in these modelling exercises is their
Data-Based Mechanistic character, whereby the model structure is not assumed,
but identified using objective statistical criteria. Complexity of the model
that is identifiable depends strongly on the available data - we can only model
the modes of behaviour of the system under investigation that are present and
'visible' in the data. This
approach to modelling is what brought me to Lancaster in the first place.
Ph.D. Students since
1999 (completion dates)
With Bill Davison and Hao Zhang
Michael Harper (2002)
Łukasz Sochaczewski (2009)
Nik Lehto (2008)With Arun Chotai and Peter Young
Jafar Sadeghi (2006)
With Nick Chappell
Ann Kretzschmar (current)
Maria Garcia-Solera (2010)
Boateng Ampadu (2008)With James Taylor (Engineering)
Eleni Sidiropoulou (2009)
With Crispin Halsall
Sara Massey (Becker) (2008)
Earlier major projects
Other academic and
technical interest and expertise areas:
Teaching:
Current work (teaching):
Main (professional)
challenges not easily categorised as research or teaching:
Before that: Joined the Lancaster Systems and
Control Group in January 1989, arriving from Warsaw, Poland to work with Peter
Young and Arun Chotai on development of new modelling and control methods and
the accompanying software.
Previous experience
includes modelling work for and with:
All of this work is related
to dynamic stochastic systems, their modelling, control and forecasting.
Personal interests
(only the main ones, and excluding work, which surprisingly, and to dismay of some,
should be on this list as well):
·
Music (jazz: Jan Garbarek and Keith Jarrett for
instance, but also classical: J.S. Bach, G.P. Telemann, Medieval and
Renaissance music)
·
Brick oven (cooking related): the
result of one summers evening work (May-September 2008) surprised both me
and my friends and family. The oven
is now used nearly each week-end and makes the best pizza I have ever tried,
along with all manners of roasted, stewed, grilled and smoked food, as well as
sourdough and other types of bread.
·
Cooking: ice-cream
[thanks Steve B - still a specialty !], but also various salads, smoked foods
and whatever comes, depending on the circumstances, supply and demand.
Sourdough bread is now a weekly ritual with very edible results.
·
Cats - until
recently exclusively a "dog person" I discovered cats as sociable and
interesting members of the family group (or should I say "pride"
now?)
·
Photography, with some of the results visible around the ES
Building in Lancaster, others on Google Earth (as Wlodek_T) as well as on Flickr.
· Sailing (on the Polish lakes mainly, as caught here on the right, but if you offer me a Med or a Scottish Isles cruise I will probably not refuse .. he says rhyming inadvertently)
Useful links
(of no interest or use
whatsoever for anyone except research partners; contains raw data files, no
description; links might be inactive as I allow access to files on demand)
page last updated: 17th March 2009 (under continuous if spasmodic
construction)