Search results for " Routing"
showing 10 items of 229 documents
Addressing Manufacturing Challenges with Cost-Efficient Fault Tolerant Routing
2010
The high-performance computing domain is enriching with the inclusion of Networks-on-chip (NoCs) as a key component of many-core (CMPs or MPSoCs) architectures. NoCs face the communication scalability challenge while meeting tight power, area and latency constraints. Designers must address new challenges that were not present before. Defective components, the enhancement of application-level parallelism or power-aware techniques may break topology regularity, thus, efficient routing becomes a challenge.In this paper, uLBDR (Universal Logic-Based Distributed Routing) is proposed as an efficient logic-based mechanism that adapts to any irregular topology derived from 2D meshes, being an alter…
Large multiple neighborhood search for the soft-clustered vehicle-routing problem
2021
Abstract The soft-clustered vehicle-routing problem (SoftCluVRP) is a variant of the classical capacitated vehicle-routing problem. Customers are partitioned into clusters and all customers of the same cluster must be served by the same vehicle. In this paper, we present a large multiple neighborhood search for the SoftCluVRP. We design and analyze multiple cluster destroy and repair operators as well as two post-optimization components, which are both based on variable neighborhood descent. The first allows inter-route exchanges of complete clusters, while the second searches for intra-route improvements by combining classical neighborhoods (2-opt, Or-opt, double-bridge) and the Balas-Simo…
A strategic oscillation simheuristic for the Time Capacitated Arc Routing Problem with stochastic demands
2021
Abstract The Time Capacitated Arc Routing Problem (TCARP) extends the classical Capacitated Arc Routing Problem by considering time-based capacities instead of traditional loading capacities. In the TCARP, the costs associated with traversing and servicing arcs, as well as the vehicle’s capacity, are measured in time units. The increasing use of electric vehicles and unmanned aerial vehicles, which use batteries of limited duration, illustrates the importance of time-capacitated routing problems. In this paper, we consider the TCARP with stochastic demands, i.e.: the actual demands on each edge are random variables which specific values are only revealed once the vehicle traverses the arc. …
Game Theoretic Decentralized Feedback Controls in Markov Jump Processes
2017
This paper studies a decentralized routing problem over a network, using the paradigm of mean-field games with large number of players. Building on a state-space extension technique, we turn the problem into an optimal control one for each single player. The main contribution is an explicit expression of the optimal decentralized control which guarantees the convergence both to local and to global equilibrium points. Furthermore, we study the stability of the system also in the presence of a delay which we model using an hysteresis operator. As a result of the hysteresis, we prove existence of multiple equilibrium points and analyze convergence conditions. The stability of the system is ill…
Aesthetic considerations for the min-max K-Windy Rural Postman Problem
2017
[EN] The aesthetic quality of routes is a feature of route planning that is of practical importance, but receives relatively little attention in the literature. Several practitioners have pointed out that the visual appeal of a proposed set of routes can have a strong influence on the willingness of a client to accept or reject a specific routing plan. While some work has analyzed algorithmic performance relative to traditional min-sum or min-max objective functions and aesthetic objective functions, we are not aware of any work that has considered a multi-objective approach. This work considers a multi-objective variant of the Min-Max K-Vehicles Windy Rural Postman Problem, discusses sever…
Drone arc routing problems
2018
[EN] In this article, we present some drone arc routing problems (Drone ARPs) and study their relation with well-known postman ARPs. Applications for Drone ARPs include traffic monitoring by flying over roadways, infrastructure inspection such as by flying along power transmission lines, pipelines or fences, and surveillance along linear features such as coastlines or territorial borders. Unlike the postmen in traditional ARPs, drones can travel directly between any two points in the plane without following the edges of the network. As a consequence, a drone route may service only part of an edge, with multiple routes being used to cover the entire edge. Thus the Drone ARPs are continuous o…
Variable Fixing for Two-Arc Sequences in Branch-Price-and-Cut Algorithms on Path-Based Models
2020
Variable fixing by reduced costs is a popular technique for accelerating the solution process of mixed-integer linear programs. For vehicle-routing problems solved by branch-price-and-cut algorithms, it is possible to fix to zero the variables associated with all routes containing at least one arc from a subset of arcs determined according to the dual solution of a linear relaxation. This is equivalent to removing these arcs from the network used to generate the routes. In this paper, we extend this technique to routes containing sequences of two arcs. Such sequences or their arcs cannot be removed directly from the network because routes traversing only one arc of a sequence might still b…
Contributions to Branch-and-Price-and-Cut Algorithms for Routing Problems
2019
This article deals with new exact branch-and-price-and-cut algorithms for the solution of routing problems. Specialized methods for the pickup-and-delivery problem (PDP), the truck-and-trailer routing problem (TTRP), the periodic vehicle routing problem (PVRP) and a service network design and hub location problem (SNDHLP) are presented. We develop a new technique for the acceleration of bidirectional labeling algorithms by a dynamic choice of the merge point. Moreover, for variants of the PDP, the bidirectional labeling can be effectively applied for the first time. In the TTRP, we model the extension to a 2 days planning horizon and the consideration of a quantity-dependent transfer time. …
GIS Infomobility for Travellers
2016
Geographical Information Systems (GIS) are essential systems to support decisions on territorial and environmental aspects. But they not always have been properly used for this purpose. Only in recent years GIS have been getting better used for the planning, management and control of the territory. The application of GIS to the transport sector has become relevant both for management and decision-making in support of Public Administration (PA) and citizens. GIS are particularly useful for roads and routing graphs management capabilities as well as for searching the most suitable path. The results achieved in this research activity aimed to evaluate different road graphs, proprietary and fre…
The last-mile vehicle routing problem with delivery options
2021
AbstractThe ongoing rise in e-commerce comes along with an increasing number of first-time delivery failures due to the absence of the customer at the delivery location. Failed deliveries result in rework which in turn has a large impact on the carriers’ delivery cost. In the classical vehicle routing problem (VRP) with time windows, each customer request has only one location and one time window describing where and when shipments need to be delivered. In contrast, we introduce and analyze the vehicle routing problem with delivery options (VRPDO), in which some requests can be shipped to alternative locations with possibly different time windows. Furthermore, customers may prefer some deli…