An Empirical Performance Comparison of Meta-heuristic Algorithms for School Bus Routing Problem

School Bus Routing Problem is an NP-hard Combinatorial Optimization problem. Thus, mega-heuristic algorithms are widely used to solve instances of the School Bus Routing Problem with large data. In this work we present a model of the School Bus Routing Problem and empirical performances comparison between three meta-heuristic algorithms named Simulated Annealing (SA), Tabu Search (TS) and Ant-Colony Optimization (ACO) on the problem. We have analyzed their performances in terms of solution quality. The results show that all three algorithms have the ability to solve the School Bus Routing Problem. In addition, computational results show that TS performed best when execution time is not restricted while ACO had relative good performance when time is restricted but poor when the time is unrestricted.Keywords:  School Bus Routing Problem; Combinatorial Optimization; Meta-heuristic Algorithm

Time-Windowed Vehicle Routing Problem: Tabu Search Algorithm Approach

Vehicle routing problem (VRP); it is defined as the problem of planning the best distribution or collection routes of the vehicles assigned to serve the scattered centers from one or more warehouses in order to meet the demands of the customers. Vehicle routing problem has been a kind of problem in which various studies have been done in recent years. Many vehicle routing problems include scheduling visits to customers who are available during certain time windows. These problems are known as vehicle routing problems with time windows (VRPTWs). In this study, a tabu search optimization is proposed for the solution of time window vehicle routing problem (VRPTWs). The results were compared with the current situation and the results were interpreted

xURLLC-Aware Service Provisioning in Vehicular Networks: A Semantic Communication Perspective

Semantic communication (SemCom), as an emerging paradigm focusing on meaning delivery, has recently been considered a promising solution for the inevitable crisis of scarce communication resources. This trend stimulates us to explore the potential of applying SemCom to wireless vehicular networks, which normally consume a tremendous amount of resources to meet stringent reliability and latency requirements. Unfortunately, the unique background knowledge matching mechanism in SemCom makes it challenging to simultaneously realize efficient service provisioning for multiple users in vehicle-to-vehicle networks. To this end, this paper identifies and jointly addresses two fundamental problems of knowledge base construction (KBC) and vehicle service pairing (VSP) inherently existing in SemCom-enabled vehicular networks in alignment with the next-generation ultra-reliable and low-latency communication (xURLLC) requirements. Concretely, we first derive the knowledge matching based queuing latency specific for semantic data packets, and then formulate a latency-minimization problem subject to several KBC and VSP related reliability constraints. Afterward, a SemCom-empowered Service Supplying Solution (S$^{\text{4}}$) is proposed along with the theoretical analysis of its optimality guarantee and computational complexity. Numerical results demonstrate the superiority of S$^{\text{4}}$ in terms of average queuing latency, semantic data packet throughput, user knowledge matching degree and knowledge preference satisfaction compared with two benchmarks.Comment: This paper has been submitted to IEEE Transactions on Wireless Communications for the second round of peer review after a major revisio

Defining Tabu List Size and Aspiration Criterion Within Tabu Search Methods

An investigation to explicitly define two key elements in tabu search methods is attempted. In this study a functional representation of the tabu list size is presented and a softer aspiration criterion is put forward. Experiments are conducted on a set of p-median problems

Solution Methods for the \u3cem\u3ep\u3c/em\u3e-Median Problem: An Annotated Bibliography

The p-median problem is a graph theory problem that was originally designed for, and has been extensively applied to, facility location. In this bibliography, we summarize the literature on solution methods for the uncapacitated and capacitated p-median problem on a graph or network

A tabu search heuristic for routing in WDM networks.

Optical networks and Wavelength-Division Multiplexing (WDM) have been widely studied and utilized in recent years. By exploiting the huge bandwidth of optical networks, WDM appears to be one of the most promising technologies to meet the dramatically increased demand for bandwidth. Since optical resources in optical networks are very expensive, development of dynamic lightpath allocation strategies, which utilize network resource efficiently, is an important area of research. We assume that there is no optical wavelength conversion device in the network, and the wavelength-continuity constraint must be satisfied. Exact optimization techniques are typically too time-consuming to be useful for practical-sized networks. In this thesis we present a tabu search based heuristic approach which is used to establish an optimal lightpath dynamically in response to a new communication request in a WDM network. As far as we know, this is the first investigation using tabu search techniques for dynamical lightpath allocation in WDM networks. We have tested our approach with networks having different sizes. And then we have compared our results with those obtained using the MILP approach. In the vast majority of cases, tabu search was able to quickly generate a solution that was optimal or near-optimal, indicating that tabu search is a promising approach for the dynamic lightpath allocation problem in WDM networks. Paper copy at Leddy Library: Theses & Major Papers - Basement, West Bldg. / Call Number: Thesis2004 .W36. Source: Masters Abstracts International, Volume: 43-01, page: 0247. Advisers: Subir Bandyopadhyay; Arunita Jaekel. Thesis (M.Sc.)--University of Windsor (Canada), 2004

Airborne Directional Networking: Topology Control Protocol Design

This research identifies and evaluates the impact of several architectural design choices in relation to airborne networking in contested environments related to autonomous topology control. Using simulation, we evaluate topology reconfiguration effectiveness using classical performance metrics for different point-to-point communication architectures. Our attention is focused on the design choices which have the greatest impact on reliability, scalability, and performance. In this work, we discuss the impact of several practical considerations of airborne networking in contested environments related to autonomous topology control modeling. Using simulation, we derive multiple classical performance metrics to evaluate topology reconfiguration effectiveness for different point-to-point communication architecture attributes for the purpose of qualifying protocol design elements

Ευρετικές μέθοδοι για την επίλυση προβλημάτων χωροθέτησης εγκαταστάσεων

Διπλωματική εργασία--Πανεπιστήμιο Μακεδονίας, Θεσσαλονίκη, 2018.Η παρούσα διπλωματική εργασία πραγματεύεται την διερεύνηση του προβλήματος διαμέσων (p-median problem). και την παρουσίαση ευρετικών μεθόδων για την επίλυσή του. Ιδιαίτερη προσοχή δίνεται στο p-median πρόβλημα στο πεδίο της χωροθέτησης μονάδων, με την επίλυση αυτού του NP-hard προβλήματος να παραμένει μια πολύ ενδιαφέρουσα πρόκληση στον τομέα της επιχειρησιακής έρευνας, ειδικά όταν αυξάνεται η διάσταση του προβλήματος. Αρχικά, πραγματοποιήθηκε μία βιβλιογραφική ανασκόπηση του p-median προβλήματος, όπως επίσης και των μεθοδολογιών επίλυσης αυτού του προβλήματος. Ακόμη, ακολούθησε η μαθηματική μοντελοποίηση του προβλήματος σε Python με χρήση του λύτη βελτιστοποίησης Gurobi ώστε να κατανοηθεί τόσο το πρόβλημα όσο και οι περιορισμοί του. Η διπλωματική εργασία στοχεύει στην ανάπτυξη ενός αποδοτικού αλγορίθμου στη γλώσσα προγραμματισμού Python, ο οποίος μπορεί να επιλύσει πραγματικά προβλήματα χωροθέτησης τα οποία προκύπτουν από δίκτυα εφοδιαστικής αλυσίδας. Η χωροθέτηση των εγκαταστάσεων είναι σημαντική παράμετρος στην εξοικονόμηση χρόνου, παραγωγής και κόστους εγκαταστάσεων. Στην εργασία το πρόβλημα της χωροθέτησης διατυπώνεται ως πρόβλημα κατανομής των εγκαταστάσεων. Συνεπώς σχεδιάστηκαν και υλοποιήθηκαν ένας άπληστος αλγόριθμος αρχικοποίησης και μια μεθευρετική μεθοδολογία Αναζήτηση Μεταβλητής Γειτνίασης - Variable Neighborhood Search, μια σχετικά πρόσφατα ανεπτυγμένη μεθευρετική μέθοδος που έχει αποδειχθεί αποτελεσματική για πολλά προβλήματα βελτιστοποίησης. Τέλος, πραγματοποιήθηκε μια συγκριτική υπολογιστική μελέτη που περιλαμβάνει την εφαρμογή του αλγορίθμου πάνω σε διαθέσιμα μετροπροβλήματα (benchmark problems) και αξιολογήθηκε η αποτελεσματικότητα του σε σύγκριση με τις ακριβής βέλτιστες τιμές των αντικειμενικών συναρτήσεων αυτών των προβλημάτων

Implementación de un híbrido entre Grasp y Tabú search para la solución del problema de programación de la producción en un ambiente Job Shop para la minimización de la tardanza total ponderada

El presente trabajo resuelve un Job shop para la minimización de la tardanza total ponderada ya que ésta es una medida de desempeño que tiene en cuenta no solo el nivel de cumplimiento de los clientes sino la importancia de los mismos. Como método de solución se propone un algoritmo híbrido entre la metodología GRASP la cual no ha sido muy estudiada para la solución de éste problema (y es de gran ayuda para la construcción inicial de una solución), y la búsqueda tabú (con la cual se han obtenido muy buenos resultados para Job Shop) para la fase de búsqueda local del algoritmo. Los resultados obtenidos se comparan con el algoritmo de búsqueda local genética propuesto por (Essafi, Mati, - Dauzère-Pérès, 2008). Éste documento presenta inicialmente el planteamiento de problema y la justificación del mismo, seguido por una explicación del problema, la meta heurística realizada, y los antecedentes relacionados con investigación del problema y métodos de solución propuestos para éste. Posteriormente se plantean los objetivos y alcance del documento, junto con el desarrollo, análisis de resultados del mismo, y finalmente algunas recomendaciones para futuros trabajos.This paper addresses a job shop problem minimizing the total weighted tardiness as this is a performance measure that takes into account, not only the level of compliance with the customers but the importance of them. The paper proposes a hybrid solution method algorithm between the GRASP methodology which has not been studied for the solution of this problem (and it is helpful for the initial construction of a solution), and Tabu search (which have obtained very good results for Job Shop) for the local search phase of the algorithm. The results obtained are compared with the local search algorithm proposed by genetic (Essafi Mati, - DauzèrePeres, 2008). This paper first presents the problem approach and its justification, followed by an explanation of the problem, metaheuristics used, relating literature to research the problem and proposed methods of solution for this. Then the objectives and scope of the document, along with the development, analysis of results, and finally some recommendations for future work are suggested.Ingeniero (a) IndustrialPregrad