Person: Artalejo Rodríguez, Jesús Manuel
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First Name
Jesús Manuel
Last Name
Artalejo Rodríguez
Affiliation
Universidad Complutense de Madrid
Faculty / Institute
Ciencias Matemáticas
Department
Area
Estadística e Investigación Operativa
Identifiers
5 results
Search Results
Now showing 1 - 5 of 5
Item Algorithmic analysis of the maximum queue length in a busy period for the M/M/c retrial queue(INFORMS Journal on Computing, 2007) Artalejo Rodríguez, Jesús Manuel; Economou, A.; López Herrero, María JesúsThis paper deals with the maximum number of customers in orbit (and in the system) during a busy period for the M/M/c retrial queue. Determining the distribution for the maximum number of customers in orbit is reduced to computation of certain absorption probabilities. By reducing to the single-server case we arrive at a closed analytic formula. For the multi-server case we develop an efficient algorithmic procedure for computation of this distribution by exploiting the special block-tridiagonal structure of the system. Numerical results illustrate the efficiency of the method and reveal interesting facts concerning the behavior of the M/M/c retrial queue.Item MCQT’06: Computational Methods and Applications in Queueing Theory(Annals of Operations Research, 2008) Artalejo Rodríguez, Jesús ManuelItem Algorithmic analysis of the Geo/Geo/c retrial queue(European journal of operational research, 2008) Artalejo Rodríguez, Jesús Manuel; Economou, A.; Gómez-Corral, AntonioIn this paper, we consider a discrete-time queue of Geo/Geo/c type with geometric repeated attempts. It is known that its continuous counterpart, namely the M/M/c queue with exponential retrials, is analytically intractable due to the spatial heterogeneity of the underlying Markov chain, caused from the retrial feature. In discrete-time, the occurrence of multiple events at each slot increases the complexity of the model and raises further computational difficulties. We propose several algorithmic procedures for the efficient computation of the main performance measures of this system. More specifically, we investigate the stationary distribution of the system state, the busy period and the waiting time. Several numerical examples illustrate the analysis.Item The M/G/1 retrial queue: New descriptors of the customer's behavior(Journal of Computational and Applied Mathematics, 2009) Artalejo Rodríguez, Jesús Manuel; Amador Pacheco, JuliaWe consider queuing systems where customers are not allowed to queue; instead of that they make repeated attempts, or retrials, in order to enter service after some time. The performance of telephone systems and communication networks modelled as retrial queues differs from standard waiting lines because typically the retrial group is an invisible queue which cannot be observed. As a result, the original flow of primary arrivals and the flow of repeated attempts become undistinguished. Our aim in this paper is to consider some aspects of this problem. Thus, we focus on the main retrial model of //1 type and investigate the distribution of the successful and blocked events made by the primary customers and the retrialcustomers.Item The single server retrial queue with finite population: a BSDE approach(Operational Research, 2012) Artalejo Rodríguez, Jesús Manuel; López Herrero, María Jesús; Matsatsinis, Nikolaos F.This paper uses the block-structured state-dependent event (BSDE) approach to generalize the scalar version of the single server retrial queue with finite population. The simple scalar version only involves exponential random variables, which make the underlying Markov chain tractable. However, this is a drawback in applications where the exponentiality is not a realistic assumption and the flows are correlated. The BSDE approach provides a versatile tool to deal with a non-exponential model with correlated flows, but keeping tractable the dimensionality of the block-structured Markov chain. We focus on the investigation of the limiting distribution of the system state and the waiting time. The theory is illustrated by numerical experiments, which demonstrate that the proposed BSDE approach can be applied efficiently