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Showing papers by "Dylan Jones published in 2007"


Journal ArticleDOI
TL;DR: A three stage model based on a multi-index model and considering several market scenarios described in an imprecise way by an expert is proposed to mitigate the uncertainty related to the market scenarios and the imprecision and/or vagueness associated with the model data.
Abstract: The aim of this work is to be a useful instrument for helping finance practitioners on the selection of suitable mutual fund portfolios. The portfolio selection problem is characterized by imprecision and/or vagueness inherent in the required data and more generally, in the context where investors have to make decisions. In order to mitigate these problems, a three stage model has been proposed based on a multi-index model and considering several market scenarios described in an imprecise way by an expert. The proposed fuzzy model allows the Decision Maker to select, by means of an outranking method, a suitable portfolio taking into account the uncertainty related to the market scenarios and the imprecision and/or vagueness associated with the model data.

61 citations


Journal ArticleDOI
TL;DR: This paper details models that determine the efficient allocation of resources on a medical assessment unit (MAU) of a general hospital belonging to the National Health Service (NHS) UK.
Abstract: This paper details models that determine the efficient allocation of resources on a medical assessment unit (MAU) of a general hospital belonging to the National Health Service (NHS) UK. The MAU was established to improve the quality of care given to acute medical patients on admission, and also provide the organizational means of rapid assessment and investigation in order to avoid unnecessary admissions. To analyse the performance of the MAU, doctors, nurses and beds are considered as the three main resources. Then a model is developed using the goal programming approach in multiobjective decision making and solved to deal with MAU performance. The developed model is solved under three different sets of patient admissions with the same resource levels using past data from the MAU. The results of the model are used to analyse the needed resource levels. Conclusions as to the appropriate staffing levels and functions of the MAU are drawn.

42 citations


Journal ArticleDOI
TL;DR: A goal programming model based around the concepts of non-standard preference functions and penalty function modelling that allows for the flexible handling of the two group classification problem is presented.

13 citations


Journal ArticleDOI
TL;DR: A new method is proposed that transforms the decision space using the geometric properties of hyper-spherical inversions to converge towards/onto the true Pareto front.

4 citations