Proceedings of XIII ISOLDE Symposium – Naples/Capri (Italy) 2014
Optimal location models in afterlife environment
Dante Alighieria, Publio M. Virgiliob
University of Dolce Stilnovo, via dei Guelfi Bianchi 13, 00123, Florence, Italy – dante.alighieri @dolcestilnovo.it
b
University of Roma La Sapienza, Eneide Square 4, 00234 Rome, Italy - publio.virgilio@uniroma.it
a
Keywords: Discrete location, afterlife, cost-benefit analysis, metaheuristic
We propose a general framework in order to determine the optimal positioning in afterlife environment.
The framework is based on a modelization of afterlife context (Aquino, 1274) through a directed graph
whose nodes, representing feasible “final” facilities, are divided into three classes (Hell, Purgatory and
Heaven), according to the scheme proposed by Alighieri (1321). Different criteria and constraints to
formulate the problem are illustrated. A specific mathematical model is then presented, considering, as
objective function, a combination of cost and benefit indicators. We show that the proposed model belongs
to the class of NP-hard problems in strong sense. A hybrid metaheuristic, based on Genetic Algorithms and
Tabu Search approaches, is then described with the introduction of barrier functions to avoid the passage
through poor solutions. Preliminary tests indicate that better solutions can be obtained with very long tabu
lists and low crossover probability. Computational experiences on randomly generated test problems show
that the proposed procedure is not able to find near-optimal solutions when most of the constraints are not
active (Boccaccio, 1353). An application to the case study described in Petrarca (1374) suggests practical
and fruitful implications and useful directions for future research.
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Main references
Alighieri D. (1321). The Divine Comedy. Medieval Literature Letters, 99:1-14233.
Aquino T. (1274). Summa Theologica. Metaphysical Analysis, 1: 1-234 (in Latin).
Boccaccio G. (1353). Decameron. Journal of Operations Management, 189:1-100.
Petrarca G. (1374). Chiare fresche et dolci acque. In Il Canzoniere (Petrarca G., Eds), Vindelino da Spira
Publisher, Venice, Italy