Mahdi zargayouna | Institut français des scineces et technologies des transports, de l'aménagement et des réseaux (original) (raw)

velers. In this paper, we propose a comparison between two methods for distributing multiagent tr... more velers. In this paper, we propose a comparison between two methods for distributing multiagent travelers mobility simulations, allowing for the consideration of realistic travelers flows and wide geographic areas.

Abstract—Vehicle Routing problems are highly complex prob-lems for which different Artificial Int... more Abstract—Vehicle Routing problems are highly complex prob-lems for which different Artificial Intelligence techniques have been used. In this paper, we propose an agent-oriented self-organization model for the dynamic version of the problem with time windows. Our proposal is based on a space-time representation of the Action Zones of the agents, which is able to maintain a good distribution of the vehicles on the environment. This distribution answers the objective of the dynamic problem, since it allows the agents to take their decisions while anticipating future changes in the system’s parameters.

IEEE Intelligent Transportation Systems Magazine, 2020

Taxis are an important transportation mode in many cities due to their convenience and accessibil... more Taxis are an important transportation mode in many cities due to their convenience and accessibility. In the taxi-dispatching problem, sometimes it is more beneficial for the supplier if taxis cruise in the network after serving the first request to pick up the next passenger, while sometimes it is better that they wait in stations for new trip requests. In this article, we propose a rolling-horizon scheme that dynamically optimizes taxi dispatching considering the actual traffic conditions. To optimize passenger satisfaction, we define a limitation for passenger waiting time. To be able to apply the method to large-scale networks, we introduce a clustering-based technique that can significantly improve the computation time without harming the solution quality. Finally, we test our method on a real test case considering taxi requests with personal car trips to reproduce actual network loading and unloading congestion during peak hours.

2019 IEEE/ACS 16th International Conference on Computer Systems and Applications (AICCSA), 2019

Modeling and simulation play an important role in transportation networks analysis. Sometimes, we... more Modeling and simulation play an important role in transportation networks analysis. Sometimes, we need to represent different scales in one simulation. Instead of creating a new multiscale simulation, we advocate for the use of existing simulations. To do so, we propose a middleware model to couple independent simulations. We consider all the necessary processing and workflows to allow for a coherent orchestration of simulations. The results show that the middleware is capable of creating a new multiscale simulation from existing ones, while minimizing the incoherence between them.

Transportation Research Part B: Methodological, 2021

Abstract Can dynamic ride-sharing reduce traffic congestion? In this paper we show that the answe... more Abstract Can dynamic ride-sharing reduce traffic congestion? In this paper we show that the answer is yes if the trip density is high, which is usually the case in large-scale networks but not in medium-scale networks where opportunities for sharing in time and space become rather limited. When the demand density is high, the dynamic ride-sharing system can significantly improve traffic conditions, especially during peak hours. Sharing can compensate extra travel distances related to operating a mobility service. The situation is entirely different in small and medium-scale cities when trip shareability is small, even if the ride-sharing system is fully optimized based on the perfect demand prediction in the near future. The reason is simple, mobility services significantly increase the total travel distance, and sharing is simply a means of combating this trend without eliminating it when the trip density is not high enough. This paper proposes a complete framework to represent the functioning of the ride-sharing system and multiple steps to tackle the curse of dimensionality when solving the problem. We address the problem for two city scales in order to compare different trip densities. A city scale of 25 k m 2 with a total market of 11,235 shareable trips for the medium-scale network and a city scale of 80 k m 2 with 205,308 demand for service vehicles for the large-scale network over a 4-hour period with a rolling horizon of 20 minutes. The solutions are assessed using a dynamic trip-based macroscopic simulation to account for the congestion effect and dynamic travel times that may influence the optimal solution obtained with predicted travel times. This outperforms most previous studies on optimal fleet management that usually consider constant and fully deterministic travel time functions.

Techniques et sciences informatiques, 2016

Lecture Notes in Computer Science, 2010

This paper discusses the security issues in data driven coordination languages. These languages r... more This paper discusses the security issues in data driven coordination languages. These languages rely on a data space shared by the agents and used to coordinate their activities. We extend these languages with a main distinguishing feature, which is the possibility to define fine-grained security conditions, associated with every datum in the shared space. Two main ideas makes it possible: the consideration of an abstraction of agents' states in the form of data at language level and the introduction of a richer interaction mechanism than state-of-the-art templates. This novel security mechanism allows both agents and system designers to prohibit undesirable interactions.

In this paper, we present a multiagent model for the Dynamic Vehicle Routing Problem with Time Wi... more In this paper, we present a multiagent model for the Dynamic Vehicle Routing Problem with Time Windows. The system adapts insertion methods to a distributed configuration. The model has two declination: one spatial and one spatiotemporal. The two organization models that we propose rely on two different measures of what the insertion of the current customer would cost to a given vehicle. Our approach provides promising results and provides a new method to tackle the problem, in which the solving process is future-centered. The models developed in this paper offer two solutions with different advantages, which allow a decider to choose one of them following the operational configuration of her real problem. In the case where the transportation operator has a limited vehicles fleet, and where the mobilization of a new vehicle is costly, its system should be grounded on the spatiotemporal model, which mobilizes less vehicles. In contrast, if the costs in term of traveled distance are more critical, it is more interesting to ground its system on the spatial model.

Lecture Notes in Computer Science, 2014

Lecture Notes in Computer Science, 2012

Online vehicle routing problems with time windows are highly complex problems for which different... more Online vehicle routing problems with time windows are highly complex problems for which different artificial intelligence techniques have been used. In these problems, the exclusive optimization of the conventional criteria (number of vehicles and total traveled distance) leads to the appearance of geographic areas and/or time periods that are not covered by any vehicle because of their low population density. The transportation demands in these zones either cannot be satisfied or need to mobilize new vehicles. We propose two agent-oriented models that propose a particular dynamic organization of the vehicles, with the objective to minimize the appearance of such areas. The first model relies on a spatial representation of the agents' action zones, and the second model is grounded on the space-time representation of these zones. These representations are capable of maintaining an equilibrated distribution of the vehicles on the transportation network. In this paper, we experimentally show that these two means of distributing vehicles over the network provide better results than traditional insertion heuristics. They allow the agents to take their decisions while anticipating future changes in the environment.

PLOS ONE, 2022

Real-time ride-sharing has become popular in recent years. However, the underlying optimization p... more Real-time ride-sharing has become popular in recent years. However, the underlying optimization problem for this service is highly complex. One of the most critical challenges when solving the problem is solution quality and computation time, especially in large-scale problems where the number of received requests is huge. In this paper, we rely on an exact solving method to ensure the quality of the solution, while using AI-based techniques to limit the number of requests that we feed to the solver. More precisely, we propose a clustering method based on a new shareability function to put the most shareable trips inside separate clusters. Previous studies only consider Spatio-temporal dependencies to do clustering on the mobility service requests, which is not efficient in finding the shareable trips. Here, we define the shareability function to consider all the different sharing states for each pair of trips. Each cluster is then managed with a proposed heuristic framework in orde...

Journal of Computing and Information Technology, 2020

Vehicle routing problems are highly complex problems. The proposals to solve them traditionally c... more Vehicle routing problems are highly complex problems. The proposals to solve them traditionally concern the optimization of conventional criteria, such as the number of mobilized vehicles and the total costs. However, in online vehicle routing problems, the optimization of the response time to the connected travelers is at least as important as the optimization of the classical criteria. Multi-agent systems on the one hand and greedy insertion heuristics on the other are among the most promising approaches to this end. In this paper, we propose a multi-agent system coupled with a regret insertion heuristic. We focus on the real-time dispatching of the travelers' requests to the vehicles and its efficiency. A dispatching protocol determines which agents perform the computation to answer the travelers' requests. We evaluate three dispatching protocols: centralized, decentralized and hybrid. We compare them experimentally based on their response time to online travelers. Two co...

Liste des tableaux ix Table des figures xi Introduction générale xiii IÉtat de l'art Chapitre 1 L... more Liste des tableaux ix Table des figures xi Introduction générale xiii IÉtat de l'art Chapitre 1 La coordination et les Systèmes Multi-Agents 2 Agent Contextual Interaction in Open Systems 3 Language for Agent Contextual Interaction in Open Systems xvi (travaillant avec des réseaux et non des plans). Nos propositions sont validés avec des expérimentations sur des benchmarks de la littérature. Organisation du rapport Cette thèse est divisée en deux parties. Chaque partie est composée de trois chapitres. Les trois premiers chapitres présentent l'état de l'art des trois différents domaines sur lesquelles nous travaillons,à savoir : les SMA et la coordination, les algèbres de processus et le Transport a la Demande. Notre présentation n'est pas exhaustive, et a pour objectif de donner les notions essentielles pour la compréhension de notre travail. Première partie.État de l'art La première partie sertà positionner notre travail età présenter les travaux antérieurs qui nous inspirent. Chapitre 1. La coordination et les systèmes muti-agents Le chapitre 1 présente unétat de l'art de la coordination en SMA et en langages de coordination. Un intérêt particulier est porté aux modèles de coordination orientés-données qui inspirent notre travail. Chapitre 2. Algèbres de processus pour la coordination Le chapitre 2 présente les algèbres de processus avant de s'étendre sur la sémantique des langages de coordination orientée-données qui ontété proposés et les principaux résultats auxquels ils ont donné lieu. Chapitre 3. Le problème du transportà la demande Le chapitre 3 donne l'état de l'art du domaine dans lequel nous appliquons le modèle et le langage. Il s'agit des problèmes de tournées de véhicules dynamiques et du problème du TransportÀ la Demande. Deuxième partie. Contributions Nous proposons le modèle de coordination Acios, le langage de coordination Lacios, ainsi que le système Lacios-TAD, une réalisation en Lacios pour les problèmes de tournées de véhicules dynamiques et leur extension TAD. Le modèle Acios définit une partie des constructeurs linguistiques du langage et les aspects conceptuels s'y afférant. Le langage Lacios complète la définition de la syntaxe et définit la sémantique du langage. Enfin, le système Lacios-TAD est un système coordonné via Acios,écrit dans Lacios et qui modélise une solution pour le problème du TransportÀ la demande. Chapitre 4. Modèle de coordination Acios Le chapitre 4 présente le modèle de coordination Acios.Étendant les modèles de coordination orientés-données présentés dans le chapitre 1, Acios se fonde sur une structure de données utilisant des couples propriétés-valeurs permettant un mécanisme d'appariement expressif et gardé xvii 22 Le problème traité y est appelé Vehicle dispatching with time-dependent travel times

2019 IEEE/ACS 16th International Conference on Computer Systems and Applications (AICCSA), 2019

The Dial-a-ride problem with time windows (DARPTW) is a highly complex problem with several opera... more The Dial-a-ride problem with time windows (DARPTW) is a highly complex problem with several operational applications. Compared to vehicle routing problems and pick up and delivery problems, the DARPTW considers the transport of persons and has, therefore, more constraints to ensure passengers satisfaction. These optimization problems can be modeled as a mixed integer program and be solved either to optimality or by applying heuristics. The exact solutions are costly in terms of computation time, especially in dynamic environments and for large-scale problems. Heuristics have the potential for fast solutions but that could be far from the optimal solutions. In this paper, we show that it is possible to propose an optimal solution for the DARPTW, which can be transformed into an efficient heuristic with a data-oriented clustering-based approach. The heuristic can be used when dealing with a highly dynamic configuration and large-scale networks. We model the DARPTW with an integer linear programming model and design an algorithm based on the branch-and-bound method to solve the mathematical model exactly. Then we introduce a method that clusters the received requests at specified times and computes the exact solution for each cluster of requests. The results show that this method can significantly decrease the computation time while keeping the quality of the solution at a satisfactory level.

AICCSA 2018 Conference, in collaboration with IEEE, continues its mission of covering all contemp... more AICCSA 2018 Conference, in collaboration with IEEE, continues its mission of covering all contemporary areas in computer systems and applications, and providing the latest results on theory, design, analysis, implementation, and application in these important and rapidly changing domains. Indeed, this edition addresses nine areas and the technical program presents high-quality papers in: (1) Knowledge Engineering, (2) Artificial Intelligence, (3) Linguistics, (4) Sensors and Networks, (5) Databases, Information Systems and Security, (6) Image processing and Computer Vision, (7) Computing, (8) Data Science, (9) Software Engineering.

2016 IEEE/ACS 13th International Conference of Computer Systems and Applications (AICCSA), 2016

Travelers mobility simulation is a powerful tool to test strategies in a virtual environment, wit... more Travelers mobility simulation is a powerful tool to test strategies in a virtual environment, without impacting the quality of the real traffic network. However, existing mobility multiagent and microsimulations can only consider a sample of the real volumes of travelers, especially for big regions. With distributed simulations, it would be easier to analyze and predict the status of nowadays networks. This kind of simulations requires big computational power and methods to split the simulation between several machines. This work describes how to achieve such a distribution in a microscopic simulation context, and compare our results with a previous work on macroscopic simulation.

Sharing rides can be an effective solution for traffic management in populated urban areas. Real-... more Sharing rides can be an effective solution for traffic management in populated urban areas. Real-time ride sharing is a dynamic and complex optimization problem. Indeed, the problem data are not known a priori in a dynamic context. However, most of the approaches in the literature consider that the missing data concerns the travelers, which are revealed online. Very few consider traffic changes during optimization or execution. More precisely, they assume that the predicted travel times used during optimization remain the same when executing the vehicle schedule, which is usually not the case in practice. In this paper, we propose a multi-agent system to solve the real-time ride-sharing problem. In this system, two models are defined to deal with dynamic traffic conditions. On the one side, the currently observed average speed in the network is used to predict travel times when calculating the optimal schedule for the ride-sharing fleet. On the other side, the traffic situation is u...

Titre: Simulation multi-agent de l’information des voyageurs dans les transports en commun.Resume... more Titre: Simulation multi-agent de l’information des voyageurs dans les transports en commun.Resume:Avec la generalisation de l'information temps-reel, le comportement des reseaux de transport modernes devient de plus en plus difficile a analyser et a prevoir. Le role de l'information est de plus en plus critique, particulierement en cas de dysfonctionnement des reseaux, et l’information devient de plus en plus personnalisee et individuelle. Plusieurs phenomenes tels que la saturation, la concentration et la sur-reaction peuvent etre observes apres l’utilisation de systemes d’information voyageurs. En effet, sans controle, la diffusion massive d'informations, a travers les panneaux a messages variables, les annonces dans les medias ainsi que les dispositifs de guidage individuel peut avoir des effets pervers et creer de nouvelles congestions. Ainsi, il est devenu important de developper des outils de simulation pour les decideurs de politiques de mobilite, prenant en compt...

Avec la generalisation de l'information temps-reel des voyageurs, le comportement des reseaux... more Avec la generalisation de l'information temps-reel des voyageurs, le comportement des reseaux de transport modernes devient de plus en plus difficile a analyser et a prevoir. Il est devenu important de developper des outils de simulation pour les decideurs de politiques de mobilite, prenant en compte ce nouvel environnement informationnel. Dans ce papier, nous presentons une simulation multi-agent pour mesurer l'impact de la fourniture d'informations sur la qualite des voyages en transports en commun. Cet impact est mesure par la simulation de scenarios differents en fonction du pourcentage de voyageurs connectes, representes par des agents. Ces scenarios sont analyses selon leur impact sur les temps de parcours moyens des voyageurs. Les resultats montrent que le nombre de voyageurs connectes a un impact positif sur les temps de parcours jusqu'a un certain seuil apres lequel il devient relativement negatif.