Dispatching Requests for Agent-Based Online Vehicle Routing Problems with Time Windows

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\u27 requests to the vehicles and its efficiency. A dispatching protocol determines which agents perform the computation to answer the travelers\u27 requests. We evaluate three dispatching protocols: centralized, decentralized and hybrid. We compare them experimentally based on their response time to online travelers. Two computational types are implemented: a sequential implementation and a distributed implementation. The results show the superiority of the centralized dispatching protocol in the sequential implementation (32.80% improvement in average compared to the distributed dispatching protocol) and the superiority of the hybrid dispatching protocol in the distributed implementation (59.66% improvement in average, compared with the centralized dispatching protocol)

A Secure Opportunistic Network with Efficient Routing for Enhanced Efficiency and Sustainability

The intersection of cybersecurity and opportunistic networks has ushered in a new era of innovation in the realm of wireless communications. In an increasingly interconnected world, where seamless data exchange is pivotal for both individual users and organizations, the need for efficient, reliable, and sustainable networking solutions has never been more pressing. Opportunistic networks, characterized by intermittent connectivity and dynamic network conditions, present unique challenges that necessitate innovative approaches for optimal performance and sustainability. This paper introduces a groundbreaking paradigm that integrates the principles of cybersecurity with opportunistic networks. At its core, this study presents a novel routing protocol meticulously designed to significantly outperform existing solutions concerning key metrics such as delivery probability, overhead ratio, and communication delay. Leveraging cybersecurity’s inherent strengths, our protocol not only fortifies the network’s security posture but also provides a foundation for enhancing efficiency and sustainability in opportunistic networks. The overarching goal of this paper is to address the inherent limitations of conventional opportunistic network protocols. By proposing an innovative routing protocol, we aim to optimize data delivery, minimize overhead, and reduce communication latency. These objectives are crucial for ensuring seamless and timely information exchange, especially in scenarios where traditional networking infrastructures fall short. By large-scale simulations, the new model proves its effectiveness in the different scenarios, especially in terms of message delivery probability, while ensuring reasonable overhead and latency

Fleet Organization Models for Online Vehicle Routing Problems

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

Fleet Organization Models for Online Vehicle Routing Problems

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

Security Threats in Intelligent Transportation Systems and Their Risk Levels

Intelligent Transport Systems (ITSs) are part of road transportation sector evolution and constitute one of the main steps towards vehicle automation. These systems use technologies that allow vehicles to communicate with each other or with road infrastructure. By increasing information quality and reliability, ITSs can improve road safety and traffic efficiency, but only if cybersecurity and data protection is ensured. With the increase in the number of cyberattacks around the world, cybersecurity is receiving increased attention, especially in the area of transportation security. However, it is equally important to examine and analyze security in depth when it concerns connected vehicles. In this paper, we propose a qualitative risk analysis of ITSs based on Threat, Risk, Vulnerability Analysis (TVRA) methodology, and we focus on ETSI ITS communication architecture. We present a review of solutions and countermeasures for identified critical attacks

Approche décentralisée pour résoudre le problème du transport à la demande

National audienceLes systèmes de transpor ts publics actuels sont déterministes. Dans de tels systèmes, c'est la demande qui s'adapte à l'offre. Dans cet ar ticle, nous proposons un modèle d'auto-organisation pour la répar tition de véhicules dans un système de transpor t à la demande (TAD) purement dynamique. Notre proposition s'appuie sur une approche décentralisée et une modélisation de l'environnement dans un système multiagent (SMA). Il s'agit de limiter la concentration des véhicules ou la famine dans cer taines régions de la ville. Nous montrons que notre modèle répond à la problématique posée dans ce domaine en permettant aux agents véhicules, pour une demande donnée, de prendre la décision finale au moyen d'un processus de négociation et de calculer des surcoûts suivant une heuristique d'insertion originale

Une approche qualité de service dans les systèmes multimédias distribués

International audienceLes applications multimédias gèrent de grandes quantités de données, dont l'exploitation doit se faire en respectant les contraintes temporelles pour permettre de "jouer" les paquets vidéo de manière fluide. Lorsque les contraintes temporelles ne sont pas respectées, la qualité de service (QdS) fournie aux utilisateurs diminue. Notre approche consiste à exploiter les travaux sur la QdS dans les SGBD temps réel afin de les appliquer aux systèmes multimédias. Dans cet article, nous présentons une architecture pour la gestion de la QdS dans les systèmes multimédias distribués, qui utilise une boucle d'ordonnancement contrôlé par rétroaction

Future internet for a personal travel companion service

The EC-funded project Instant Mobility is defining a comprehensive architecture for transport and mobility applications that aim to innovate by introducing future Internet technologies to this domain. A set of core enabling technologies are being developed by other projects in the Future Internet PPP such as FI-WARE, while the transport domain Instant Mobility project will use these generic enablers where available, and will develop its own enablers where necessary. In this paper, we describe an Internet-based “multimodal travel platform” that provides information and services able to support new types of connected transport applications. The considered scenario, a “Personal Travel Companion”, is centred on multimodal travellers (both drivers and passengers). Almost all modes of transport are present in this scenario: private car, public transport modes, car sharing, ride sharing, bikes, etc. The project defines requirements for future Internet technology tools and enablers that can support services available to any Internet-connected traveller, whether using a portable, vehicle-based or fixed terminal. Future Internet technologies offer new horizons for transport information systems and propose for travellers a new experience with means of transport. We are designing and implementing a prototype for multimodal travel assistance taking advantage of these technologies. A demonstration of the application is planned in the ITS world congress - Vienna 2012, while the final prototype is due on March 2013.&nbsp

CBR-Mining Approach to Improve Learning System Engineering in a Collaborative E-Learning Platform

International audienc