Dr Bernard Torsney
- Honorary Research Fellow (School of Mathematics & Statistics)
Research interests
I have a long standing interest in the area of optimal regression design or optimal designs for models with both qualitative and quantitative inputs. This covers both linear and non-linear models. These designs need to be determined numerically. I have proposed algorithms for determining optimal design weights; i.e. the proportions of observations to be taken at given design points. These are multiplicative in form, neatly ensuring the constraints which weights must satisfy. I have applied these methods to other examples of this kind of problem, including various maximum likelihood estimation problems. A current interest is paired comparisons and ranking data. There is scope for developing a rich class of models for such data, whose parameters can be taken to be weights. Numerical techniques are needed to determine maximum likelihood estimates. Other examples arise in sampling problems.
In the design context too these algorithms can be used to determine the design points at which observations should be taken. In the one design variable case these must lie in a finite design interval under a linear model. The design points therefore split the design interval into sub-intervals, which form proportions of the whole interval. Determining these proportions optimally determines the design points. A similar problem arises in determining cut-points for survey questions on items or variables such as income, given an assumed distribution for the variable. This in fact is an extension of optimal designing for binary response models to multinomial ones. Particular applications arise in Contingent Valuation or Willingness To Pay studies.
In almost of these areas there also arise problems in which several optimising distributions are sought. A recent example is that of determining optimal conditional designs when there is control over only some terms in a model, while the others are known prior to experimenting. Designs conditional on these known values are sought. Examples also arise in the paired comparisons and ranking data context when comparisons are made in respect of several attributes. Also the relaxation labelling approach to pixel categorisation (of each pixel) in image analysis is of a similar flavour. Our class of algorithm readily extends to this scenario.
Publications
2023
Gündüz, N. and Torsney, B. (2023) D-optimal designs for binary and weighted linear regression models: one design variable. Mathematics, 11(9), 2075. (doi: 10.3390/math11092075)
2017
Chambers, S. , Dundas, R. and Torsney, B. (2017) School and local authority characteristics associated with take-up of free school meals in Scottish secondary schools, 2014. In: Milne, Robin G. (ed.) Civic Engagement. Series: Contemporary issues in social science. Routledge. ISBN 9781138080171
Mandal, S., Torsney, B. and Chowdhury, M. (2017) Optimal designs for minimising covariances among parameter estimators in a linear model. Australian and New Zealand Journal of Statistics, 59(3), pp. 255-273. (doi: 10.1111/anzs.12195)
Rathcke, T., Stuart-Smith, J. , Torsney, B. and Harrington, J. (2017) The beauty in a beast: minimising the effects of diverse recording quality on vowel formant measurements in sociophonetic real-time studies. Speech Communication, 86, pp. 24-41. (doi: 10.1016/j.specom.2016.11.001)
Casero-Alonso, V., López-Fidalgo, J. and Torsney, B. (2017) A computer tool for a minimax criterion in binary response and heteroscedastic simple linear regression models. Computer Methods and Programs in Biomedicine, 138, pp. 105-115. (doi: 10.1016/j.cmpb.2016.10.009) (PMID:27886709)
2016
Chambers, S. , Dundas, R. and Torsney, B. (2016) School and local authority characteristics associated with take-up of free school meals in Scottish secondary schools, 2014. Contemporary Social Science, 11(1), pp. 52-63. (doi: 10.1080/21582041.2016.1223871) (PMID:28191363) (PMCID:PMC5259801)
2012
Govan, L. et al. (2012) The effect of deprivation and HbA1c on admission to hospital for diabetic ketoacidosis in type 1 diabetes. Diabetologia, 55(9), pp. 2356-2360. (doi: 10.1007/s00125-012-2601-6)
2010
Giovagnoli, A., Atkinson, A.C., Torsney, B. and May, C. (2010) mODa 9 Advances in Model Oriented Design and Analysis : Proceedings of the 9th International Workshop in Model-Oriented Design and Analysis held in Bertinoro, Italy, June 14-18, 2010 [Proceedings editors]. Series: Contributions to Statistics. Springer-Verlag: Heidelberg. ISBN 9783790824094 (doi: 10.1007/978-3-7908-2410-0)
Torsney, B. (2010) Estimation and optimal designing under latent variable models for paired comparisons studies via a multiplicative algorithm. Contributions to Statistics, 2010, pp. 213-220. (doi: 10.1007/978-3-7908-2410-0_28)
2009
Torsney, B. and Martin-Martin, R. (2009) Multiplicative algorithms for computing optimal designs. Journal of Statistical Planning and Inference, 139(12), pp. 3947-3961. (doi: 10.1016/j.jspi.2009.05.007)
Torsney, B. (2009) W-Iterations and Ripples Therefrom. In: Pronzato, L. and Zhigljavsky, A. (eds.) Optimal Design and Related Areas in Optimization and Statistics. Series: Springer Series in Optimization and Its Applications (28). Springer: New York, pp. 1-12. ISBN 978-0-387-79935-3
2007
Martin-Martin, R., Torsney, B. and Lopez-Fidalgo, J. (2007) Construction of marginally and conditionally restricted designs using multiplicative algorithms. Computational Statistics and Data Analysis, 51, pp. 5547-5561. (doi: 10.1016/j.csda.2007.03.025)
Waddell, G., O'Connor, M., Boorman, S. and Torsney, B. (2007) Working backs Scotland - A public and professional health education campaign for back pain. Spine, 32, pp. 2139-2143. (doi: 10.1097/BRS.0b013e31814541bc)
2006
Gunduz, N. and Torsney, B. (2006) Some advances in optimal designs in contingent valuation studies. Journal of Statistical Planning and Inference, 136, pp. 1153-1165. (doi: 10.1016/j.jspi.2004.08.004)
Mandal, S. and Torsney, B. (2006) Construction of optimal designs using a clustering approach. Journal of Statistical Planning and Inference, 136, pp. 1120-1134. (doi: 10.1016/j.jspi.2004.08.005)
Milne, R., Horne, M. and Torsney, B. (2006) SMS reminders in the UK national health service: An evaluation of its impact on "No-Shows" at hospital out-patient clinics. Health Care Management Review, 31, pp. 130-136.
Torsney, B. and Mandal, S. (2006) Two classes of multiplicative algorithms for constructing optimizing distributions. Computational Statistics and Data Analysis, 51, pp. 1591-1601. (doi: 10.1016/j.csda.2006.05.014)
2005
Mandal, S., Torsney, B. and Carriere, K. (2005) Constructing optimal designs with constraints. Journal of Statistical Planning and Inference, 128, pp. 609-621. (doi: 10.1016/j.jspi.2003.12.003)
2003
Milne, R. and Torsney, B. (2003) Financial incentives, competition and a two tier service: lessons from the UK National Health Service internal market. Health Policy, 64, pp. 1-12. (doi: 10.1016/S0168-8510(02)00159-8)
1992
1983
1978
Silvey, S.D., Titterington, D.H. and Torsney, B. (1978) An algorithm for optimal designs on a design space. Communications in Statistics: Theory and Methods, 7(14), pp. 1379-1389. (doi: 10.1080/03610927808827719)
Articles
Gündüz, N. and Torsney, B. (2023) D-optimal designs for binary and weighted linear regression models: one design variable. Mathematics, 11(9), 2075. (doi: 10.3390/math11092075)
Mandal, S., Torsney, B. and Chowdhury, M. (2017) Optimal designs for minimising covariances among parameter estimators in a linear model. Australian and New Zealand Journal of Statistics, 59(3), pp. 255-273. (doi: 10.1111/anzs.12195)
Rathcke, T., Stuart-Smith, J. , Torsney, B. and Harrington, J. (2017) The beauty in a beast: minimising the effects of diverse recording quality on vowel formant measurements in sociophonetic real-time studies. Speech Communication, 86, pp. 24-41. (doi: 10.1016/j.specom.2016.11.001)
Casero-Alonso, V., López-Fidalgo, J. and Torsney, B. (2017) A computer tool for a minimax criterion in binary response and heteroscedastic simple linear regression models. Computer Methods and Programs in Biomedicine, 138, pp. 105-115. (doi: 10.1016/j.cmpb.2016.10.009) (PMID:27886709)
Chambers, S. , Dundas, R. and Torsney, B. (2016) School and local authority characteristics associated with take-up of free school meals in Scottish secondary schools, 2014. Contemporary Social Science, 11(1), pp. 52-63. (doi: 10.1080/21582041.2016.1223871) (PMID:28191363) (PMCID:PMC5259801)
Govan, L. et al. (2012) The effect of deprivation and HbA1c on admission to hospital for diabetic ketoacidosis in type 1 diabetes. Diabetologia, 55(9), pp. 2356-2360. (doi: 10.1007/s00125-012-2601-6)
Torsney, B. (2010) Estimation and optimal designing under latent variable models for paired comparisons studies via a multiplicative algorithm. Contributions to Statistics, 2010, pp. 213-220. (doi: 10.1007/978-3-7908-2410-0_28)
Torsney, B. and Martin-Martin, R. (2009) Multiplicative algorithms for computing optimal designs. Journal of Statistical Planning and Inference, 139(12), pp. 3947-3961. (doi: 10.1016/j.jspi.2009.05.007)
Martin-Martin, R., Torsney, B. and Lopez-Fidalgo, J. (2007) Construction of marginally and conditionally restricted designs using multiplicative algorithms. Computational Statistics and Data Analysis, 51, pp. 5547-5561. (doi: 10.1016/j.csda.2007.03.025)
Waddell, G., O'Connor, M., Boorman, S. and Torsney, B. (2007) Working backs Scotland - A public and professional health education campaign for back pain. Spine, 32, pp. 2139-2143. (doi: 10.1097/BRS.0b013e31814541bc)
Gunduz, N. and Torsney, B. (2006) Some advances in optimal designs in contingent valuation studies. Journal of Statistical Planning and Inference, 136, pp. 1153-1165. (doi: 10.1016/j.jspi.2004.08.004)
Mandal, S. and Torsney, B. (2006) Construction of optimal designs using a clustering approach. Journal of Statistical Planning and Inference, 136, pp. 1120-1134. (doi: 10.1016/j.jspi.2004.08.005)
Milne, R., Horne, M. and Torsney, B. (2006) SMS reminders in the UK national health service: An evaluation of its impact on "No-Shows" at hospital out-patient clinics. Health Care Management Review, 31, pp. 130-136.
Torsney, B. and Mandal, S. (2006) Two classes of multiplicative algorithms for constructing optimizing distributions. Computational Statistics and Data Analysis, 51, pp. 1591-1601. (doi: 10.1016/j.csda.2006.05.014)
Mandal, S., Torsney, B. and Carriere, K. (2005) Constructing optimal designs with constraints. Journal of Statistical Planning and Inference, 128, pp. 609-621. (doi: 10.1016/j.jspi.2003.12.003)
Milne, R. and Torsney, B. (2003) Financial incentives, competition and a two tier service: lessons from the UK National Health Service internal market. Health Policy, 64, pp. 1-12. (doi: 10.1016/S0168-8510(02)00159-8)
Ford, I. , Torsney, B. and Wu, C.F.J. (1992) The use of a canonical form in the construction of locally optimal designs for non-linear problems. Journal of the Royal Statistical Society: Series B (Statistical Methodology), 54(2), pp. 569-583.
Torsney, B. (1983) A moment inequality and monotonicity of an algorithm. Lecture Notes in Economics and Mathematical Systems, 215, pp. 249-260.
Silvey, S.D., Titterington, D.H. and Torsney, B. (1978) An algorithm for optimal designs on a design space. Communications in Statistics: Theory and Methods, 7(14), pp. 1379-1389. (doi: 10.1080/03610927808827719)
Books
Giovagnoli, A., Atkinson, A.C., Torsney, B. and May, C. (2010) mODa 9 Advances in Model Oriented Design and Analysis : Proceedings of the 9th International Workshop in Model-Oriented Design and Analysis held in Bertinoro, Italy, June 14-18, 2010 [Proceedings editors]. Series: Contributions to Statistics. Springer-Verlag: Heidelberg. ISBN 9783790824094 (doi: 10.1007/978-3-7908-2410-0)
Book Sections
Chambers, S. , Dundas, R. and Torsney, B. (2017) School and local authority characteristics associated with take-up of free school meals in Scottish secondary schools, 2014. In: Milne, Robin G. (ed.) Civic Engagement. Series: Contemporary issues in social science. Routledge. ISBN 9781138080171
Torsney, B. (2009) W-Iterations and Ripples Therefrom. In: Pronzato, L. and Zhigljavsky, A. (eds.) Optimal Design and Related Areas in Optimization and Statistics. Series: Springer Series in Optimization and Its Applications (28). Springer: New York, pp. 1-12. ISBN 978-0-387-79935-3
Research datasets
2016
Chambers, S., Dundas, R. and Torsney, B. (2016) School and local authority characteristics associated with take-up of Free School Meals in Scottish secondary schools 2014. [Data Collection]