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Artigues C.,Roche Holding AG | Artigues C.,Toulouse 1 University Capitole | Huguet M.-J.,Roche Holding AG | Huguet M.-J.,INSA Toulouse | And 4 more authors.
Transportation Research Part C: Emerging Technologies | Year: 2013

Taking into account the multi-modality of urban transportation networks for computing the itinerary of an individual passenger introduces a number of additional constraints such as mode restrictions and various objective functions. In this paper, constraints on modes are gathered under the concept of viable path, modeled by a nondeterministic finite state automaton (NFA). The goal is to find the non-dominated viable shortest paths considering the minimization of the travel time and of the number of modal transfers. We show that the problem, initially considered by Lozano and Storchi (2001), is a polynomially-solvable bi-objective variant of the mono-objective regular language-constrained shortest path problem (Barett et al., 2000; Delling et al., 2009).We propose several label setting algorithms for solving the problem: a topological label-setting algorithm improving on algorithms proposed by Pallottino and Scutellà (1998) and Lozano and Storchi (2001), a multi-label algorithm using buckets and its bidirectional variant, as well as dedicated goal oriented techniques. Furthermore, we propose a new NFA state-based dominance rule. The computational experiments, carried-out on a realistic urban network, show that the state-based dominance rule associated with bidirectional search yields significant average speed-ups. On an expanded graph comprising 1,859,350 nodes, we obtain on average 3.5 non-dominated shortest paths in less than 180 ms. © 2012 Elsevier Ltd. Source

Gendre P.,CETE Mediterranee | Campens X.,CETE Mediterranee | Seng J.,Agency for Defense Development | Etienne M.,Dryade Cityway | And 2 more authors.
19th Intelligent Transport Systems World Congress, ITS 2012 | Year: 2012

This article presents an approach for interoperability of travel information services based on two layers: a directory of transport information services, and open web services. The approach would enable end-users to navigate in the transport information, much as they navigate between transport modes in the real world. We present corresponding prototype implementations under development in France, that aim at standardising Public Transport information web services, and referencing them in a national directory of multimodal transport information services. Source

Artigues C.,CNRS Laboratory for Analysis and Architecture of Systems | Artigues C.,Toulouse 1 University Capitole | Deswarte Y.,CNRS Laboratory for Analysis and Architecture of Systems | Deswarte Y.,Toulouse 1 University Capitole | And 17 more authors.
ACM International Conference Proceeding Series | Year: 2012

We present the AMORES project, which aims to provide an architecture for the provision of privacy preserving and resilient collaborative services in "mobiquitous" (i.e., mobile and ubiquitous) systems. The project is built around three use-cases from the area of public transportation: (1) dynamic carpooling, (2) real-time computation of multimodal transportation itineraries and (3) mobile social networking. Four main research tasks are presented in this paper. The first task deals with use-cases, prototypes and privacy assessment. The second task addresses geo-communication primitives: verified positioning, locanyms and geo-services. The third task deals with privacy-preserving communication means such as anonymous routing and geo-cryptography. Finally, the last task is devoted to collaborative behaviors. © 2012 ACM. Source

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