El Dr. Javier Del Ser, investigador principal y responsable tecnológico del área OPTIMA (Optimización, Modelización y Analítica de Datos) de TECNALIA, ha colaborado con investigadores del Departamento de Ingeniería de Comunicaciones de la UPV/ECHU en sendas ponencias presentadas en la segunda edición del congreso internacional ICHSA 2015 (2nd International Conference on Harmony Search Algorithm), celebrada en Seul (Corea del Sur) entre el 19 y 21 de agosto de 2015.
En estas ponencias tituladas “A Harmony Search Approach for the Selective Pick-up and Delivery Problem with Delayed Drop-off” y “Dandelion-Encoded Harmony Search Heuristics for Opportunistic Traffic Ooading in Synthetically Modeled Mobile Networks” se analiza la aplicabilidad del algoritmo evolutivo Harmony Search para la resolución de determinados problemas de rutado y asignación de recursos en redes de transporte y comunicaciones, fácilmente extrapolables a paradigmas de gestión de inventarios y planificación en escenarios industriales.
Abstract “A Harmony Search Approach for the Selective Pick-up and Delivery Problem with Delayed Drop-off”
In the last years freight transportation has undergone a sharp increase in the scales of its underlying processes and protocols mainly due to the ever-growing community of users and the increasing number of on-line shopping stores. Furthermore, when dealing with the last stage of the shipping chain an additional component of complexity enters the picture as a result of the fixed availability of the destination of the good to be delivered. As such, business opening hours and daily work schedules often clash with the delivery times programmed by couriers along their routes. In case of conflict, the courier must come to an arrangement with the destination of the package to be delivered or, alternatively, drop it o at a local depot to let the destination pick it up at his/her time convenience. In this context this paper will formulate a variant of the so-called courier problem under economic protability criteria including the cost penalty derived from the delayed drop-off. In this context, if the courier delivers the package to its intended destination before its associated deadline, he is paid a reward. However, if he misses to deliver in time, the courier may still deliver it at the destination depending on its availability or, alternatively, drop it o at the local depot assuming a certain cost. The manuscript will formulate the mathematical optimization problem that models this logistics process and solve it eciently by means of the Harmony Search algorithm. A simulation benchmark will be discussed to validate the solutions provided by this meta-heuristic solver and to compare its performance to other algorithmic counterparts.
Abstract “Dandelion-Encoded Harmony Search Heuristics for Opportunistic Trac Ooading in Synthetically Modeled Mobile Networks”
The high data volumes being managed by and transferred through mobile networks in the last few years are the main rationale for the upsurge of research aimed at nding ecient technical means to ooad exceeding trac to alternative communication infrastructures with higher transmission bandwidths. This idea is solidly buttressed by the proliferation of short-range wireless communication technologies (e.g. mobile devices with multiple radio interfaces), which can be conceived as available opportunistic hotspots to which the operator can reroute exceeding network trac depending on the contractual clauses of the owner at hand. Furthermore, by ooading to such wireless hotspots a higher eective coverage can be attained by those operators providing both mobile and xed telecommunication services. In this context, the operator must decide if data generated by its users will be sent over conventional 4G+/4G/3G communication links, or if they will instead be ooaded to nearby opportunistic networks assuming a contractual cost penalty. Mathematically speaking, this problem can be formulated as a spanning tree optimization subject to cost-performance criteria and coverage constraints. This paper will elaborate on the ecient solving of this optimization paradigm by means of the Harmony Search meta-heuristic algorithm and the so-called Dandelion solution encoding, the latter allowing for the use of conventional meta-heuristic operators maximally preserving the locality of tree representations. The manuscript will discuss the obtained simulation results over dierent synthetically modeled setups of the underlying communication scenario and contractual clauses of the users.