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Evaluating the performances of over-the-counter companies in developing countries using a stochastic dominance criterion and a PSO-ANN hybrid optimization model (2020)
Journal Article
Nasseri, A., Jamshidi, S., Yazdifar, H., Percy, D., & Alam, M. (2020). Evaluating the performances of over-the-counter companies in developing countries using a stochastic dominance criterion and a PSO-ANN hybrid optimization model. Journal of Applied Accounting Research, 21(3), 563-582. https://doi.org/10.1108/JAAR-09-2019-0137

With suitable optimization criteria, hybrid models have proven to be efficient for preparing portfolios in capital markets of developed countries. This study adapts and investigates these methods for a developing country, so providing a novel approac... Read More about Evaluating the performances of over-the-counter companies in developing countries using a stochastic dominance criterion and a PSO-ANN hybrid optimization model.

A comparison of Olympic and Paralympic performances (2018)
Journal Article
Percy, D. (2019). A comparison of Olympic and Paralympic performances. Journal of the Operational Research Society, 70(3), 446-458. https://doi.org/10.1080/01605682.2018.1447246

In 2012, Oscar Pistorius created history as the first amputee sprinter to compete in the Olympics. Other athletes achieved amazing feats long before the Paralympics were introduced, including gymnast George Eyser who won six medals at the 1904 Olym... Read More about A comparison of Olympic and Paralympic performances.

A mathematical analysis of badminton scoring systems (2015)
Book Chapter
Percy, D. (2015). A mathematical analysis of badminton scoring systems. In M. Wright (Ed.), Operational Research Applied to Sports (181-200). Basingstoke: Palgrave Macmillan

The International Badminton Federation recently introduced rule changes to make the game faster and more entertaining, by influencing how players score points and win games. We assess the fairness of both systems by applying combinatorics, probabilit... Read More about A mathematical analysis of badminton scoring systems.

Reliability equivalence factors for a series–parallel system of components with exponentiated Weibull lifetimes (2015)
Journal Article
Alghamdi, S., & Percy, D. (2015). Reliability equivalence factors for a series–parallel system of components with exponentiated Weibull lifetimes. IMA Journal of Management Mathematics, 28(3), 339-358. https://doi.org/10.1093/imaman/dpv001

We study reliability equivalence factors of a system of independent and identical components with exponentiated Weibull lifetimes. The system has n subsystems connected in parallel and subsystem i has m_i components connected in series, i=1,...,n. We... Read More about Reliability equivalence factors for a series–parallel system of components with exponentiated Weibull lifetimes.

Strategy selection and outcome prediction in sport using dynamic learning for stochastic processes (2015)
Journal Article
Percy, D. (2015). Strategy selection and outcome prediction in sport using dynamic learning for stochastic processes. Journal of the Operational Research Society, 66(11), 1840-1849. https://doi.org/10.1057/jors.2014.137

We study reliability equivalence factors of a system of independent and identical components with exponentiated Weibull lifetimes. The system has n subsystems connected in parallel and subsystem i has mi components connected in series, i=1,…,n. We co... Read More about Strategy selection and outcome prediction in sport using dynamic learning for stochastic processes.

Responding to the needs of students who are carers on an undergraduate occupational therapy programme at one UK university (2015)
Journal Article
Hussain, Z., Higginson, M., Pickering, V., & Percy, D. (2015). Responding to the needs of students who are carers on an undergraduate occupational therapy programme at one UK university. Student engagement and experience journal, 4(1), 1-18. https://doi.org/10.7190/seej.v4i1.92

The purpose of the study was to explore the experiences of students on an undergraduate occupational therapy degree programme who have caring responsibilities. It was a mixed methods study, including a questionnaire to identify students who are carer... Read More about Responding to the needs of students who are carers on an undergraduate occupational therapy programme at one UK university.

Reliability equivalence factors for a series-parallel system assuming an exponentiated weibull distribution (2014)
Book Chapter
Alghamdi, S., & Percy, D. (2014). Reliability equivalence factors for a series-parallel system assuming an exponentiated weibull distribution. In S. Wu (Ed.), Proceedings of 8th IMA International Conference on Modelling in Industrial Maintenance and Reliability. Institute of Mathematics and its Applications

In this study, we discuss the reliability equivalence factors of a series-parallel system with n series subsystems connected in parallel where subsystem i has m(i) independent and identically distributed components. We assume that each component has... Read More about Reliability equivalence factors for a series-parallel system assuming an exponentiated weibull distribution.

Predictions of relative risks for dengue disease mapping in Malaysia based on stochastic SIR-SI vector-borne infectious disease transmission model (2014)
Book Chapter
Samat, N., & Percy, D. (2014). Predictions of relative risks for dengue disease mapping in Malaysia based on stochastic SIR-SI vector-borne infectious disease transmission model. In A. Kasim, W. Omar, N. Razak, N. Musa, R. Halim, & S. Mohamed (Eds.), Proceedings of the International Conference on Science, Technology and Social Sciences (ICSTSS) 2012 (399-404). Singapore: Springer

The main aim of this paper is to propose a procedure for predicting relative risk in order to suggest approximate future dengue disease progression patterns for Malaysia. Firstly, we discuss the posterior predictive distributions that are used to gen... Read More about Predictions of relative risks for dengue disease mapping in Malaysia based on stochastic SIR-SI vector-borne infectious disease transmission model.

The optimal dartboard? (2012)
Journal Article
Percy, D. (2012). The optimal dartboard?. Mathematics today, 48, 268-270

Our challenge is to determine the best arrangement of the numbers 1,2,...,20 on a dartboard. This problem has been tackled before but we consider a new constraint and a different optimality criterion that lead to an original solution.

Generic handicapping for paralympic sports (2012)
Journal Article
Percy, D. (2012). Generic handicapping for paralympic sports. IMA Journal of Management Mathematics, 24(3), 349-361. https://doi.org/10.1093/imaman/dps013

Class handicapping methods enable different classes of athletes to compete on equal terms. Different sports use a variety of algorithms, which are usually based on historical data and subjective opinions. A recent proposal is to use an interactive sh... Read More about Generic handicapping for paralympic sports.

Vector borne infectious disease mapping with stochastic difference equations : an analysis of dengue disease in Malaysia (2012)
Journal Article
Samat, N., & Percy, D. (2012). Vector borne infectious disease mapping with stochastic difference equations : an analysis of dengue disease in Malaysia. Journal of Applied Statistics, 39(9), 2029-2046. https://doi.org/10.1080/02664763.2012.700450

Few publications consider the estimation of relative risk for vector borne infectious diseases. Most of these articles involve exploratory analysis that includes the study of covariates and their effects on disease distribution and the study of geogr... Read More about Vector borne infectious disease mapping with stochastic difference equations : an analysis of dengue disease in Malaysia.

Modelling uncertainty in preventive maintenance scheduling (2012)
Journal Article
Bell, S., & Percy, D. (2012). Modelling uncertainty in preventive maintenance scheduling. Quality and Reliability Engineering International, 28(6), 604-615. https://doi.org/10.1002/qre.1409

In this article we consider the practical implementation of Bayesian methodology in determining the optimal preventive maintenance (PM) interval for a complex repairable system. The behaviour of this system is described using a probabilistic model b... Read More about Modelling uncertainty in preventive maintenance scheduling.

Multivariate counting processes with application to repairable systems (2012)
Thesis
Bell, S. Multivariate counting processes with application to repairable systems. (Thesis). University of Salford

Survival processes and recurrent event processes are the subject of many texts. The works of Kalbfleisch and Prentice (2002), Cook and Lawless (2008) and Aalen et al. (2008) all provide detailed discussion of univariate event processes on which we... Read More about Multivariate counting processes with application to repairable systems.

Interactive shrinkage methods for class handicapping (2011)
Journal Article
Percy, D. (2011). Interactive shrinkage methods for class handicapping. IMA Journal of Management Mathematics, 22(2), 139-156

A recent publication identified weaknesses with the current handicapping system for disabled Alpine skiing, suggested minor improvements and tentatively proposed an alternative system. This proposal uses shrinkage methods to allow for varying class s... Read More about Interactive shrinkage methods for class handicapping.