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In this paper, we focus on solving location-routing problem that belongs to NP-hard problems and that often appears in the optimization of supply chain and distribution systems. The goal of location-routing problem is to determine the location of multiple depots together with vehicle routes such that the total cost of the system is minimal. A genetic algorithm is proposed to solve a deterministic...
The boost of wireless technology brings dramatic growth for Vehicular ad-hoc networks(VANETs). The effective routing and forwarding protocol is critical for the performance of VANETs thus influence the automatic driving and information distribution. The dynamic characteristic of vehicle to vehicle(V2V) communications makes it hard to maintain a reliable path between vehicles. In order to improve transmission...
Vehicle routing is a critical factor in reducing transportation costs. Finding optimal vehicle routes offers great potential to efficiently manage fleets, reduce costs and improve service quality. An effective scheme to manage fleets and determine vehicle routes for delivering goods is important for carriers to survive. In the existing literature, a variety of vehicle routing problems (VRP) have been...
WiFi access points, mesh routers, wireless sensors and any other wireless routers along the road can serve as roadside unit (RSU), and these RSUs can provide infrastructural supports for wireless access and data dissemination in cyber-transportation systems. We present a hybrid routing scheme in vehicular networks for inter-vehicle, vehicle-to-roadside and inter-roadside data dissemination in urban...
Vehicle Routing Problem (VRP) is a well known NP-hard optimization problem with a number of real world applications and a variety of different versions. Due to its complexity, large instances of VRP are hard to solve using exact methods. Instead, various heuristic and meta-heuristic algorithms were used to find feasible VRP solutions. This work proposes a Differential Evolution for VRP that simultaneously...
In vehicular ad hoc networks (VANETs), designing an efficient routing protocol is particularly challenging due to the vehicle movement and lossy wireless channel. A packet can be lost at a forwarder node even when a proper node is selected as the forwarder. In this paper, we propose a loss-tolerant scheme for unicast routing protocols in VANETs. The proposed scheme uses multiple forwarder nodes to...
The artificial bee colony algorithm (ABC) with three loading heuristics for the two-dimensional loading capacitated vehicle routing problem (2L-CVRP) is presented in the paper. The 2L-CVRP is a combination of two well-known NP-hard problems, the capacitated vehicle routing problem, and the two-dimensional bin packing problem. It is very difficult to get a good performance solution in practice for...
The Capacitated Vehicle Routing Problem (CVRP) is a widely studied, NP-hard problem with many real-world applications. Exact approaches are infeasible for solving large problem instances, due to the superpolynomial time complexity. Therefore, most solution approaches over the years have been metaheuristics, such as the Genetic Algorithm (GA). This paper presents a Hybrid GA, which incorporates problem-specific...
The vehicle routing problem is a class of problems that frequently occurs in the field of transportation logistics. In this work, we tackle very-large scale problem instances with time windows. Among other techniques, metaheuristics are frequently used to solve large-scale instances close to optimality. We present an island-model genetic algorithm variant and apply several techniques such as offspring...
Aiming at the capacitated vehicle routing problem (CVRP) in the matter stream delivery field, an improved genetic algorithm (GA) based on local mutation operator is adopted. Two layers chromosome coding scheme is designed which can improve initial solutions. This coding method can insure that the sub-routing is effective to satiety the vehicle capacitated constraints. These improved measures have...
Based on the traditional theory and algorithms of vehicle routing problem, the multi-objective VRPSDP mathematical model is established in considering the minimum of the number of vehicles and the transportation costs. The genetic algorithm is used as the solving algorithm of the model in this paper, in order to ensure the effectiveness of the chromosomes in the iterative process, the chromosome encoding...
Vehicle routing problem with time window (VRPTW) is a very important combinatorial optimization and nonlinear programming problem and it has important practical value in the field of transportation, distribution and logistics. Traditional intelligent optimization algorithms have the common defects of early convergence and easily falling into local optimal solution in solving VRPTW. An improved hybrid...
With the rapid development of electronic commerce and logistics distribution, multi-depot vehicle routing problem with time windows (MDVRPTW) as influencing electronic commerce more step development, has been paid more attentions. According to the characteristics of model, hybrid heuristic algorithm is used to get the optimization solution. First of all, use hybrid coding so as to simplify the problem,...
This study primarily focuses on solving the vehicle routing problem with soft time windows (VRPSTW) by applying an improved double-population genetic algorithm (DPGA). The traditional single-population genetic algorithm (SPGA) in solving vehicle routing problem usually traps in local optimum or consumes considerable time. In this paper two different initialization methods - random initialization method...
The design of distribution networks is one of the most important problems in supply chain and logistics management. The main elements in designing a distribution network are location and routing decisions. As these elements are interdependent in many distribution networks, the overall system cost can decrease if location and routing decisions are simultaneously tackled. In this paper, we consider...
Vehicle routing problem (VRP) is an important and well-known combinatorial optimization problem encountered in many transport logistics and distribution systems. The VRP has several variants depending on tasks performed and on some restrictions, such as time windows, multiple vehicles, backhauls, simultaneous delivery and pick-up, etc. In this paper, we consider vehicle routing problem with simultaneous...
A particular three-layer capacitated location-routing problem is investigated in which there exist two echelons of facilities to be located. A Lagrangian relaxation is used to separate the problem and obtain lower bound. Subgradient optimization is used to improve the lower bound and feedback information among the sub problems. Genetic algorithm and other heuristics are used to solve subproblems....
Usually, the combinatorial optimization problems are modeled in a static way. All data are known in advance, i.e., before the optimization process has started. But in practice, many problems are dynamic, and change during the time. For the Dynamic Vehicle Routing Problem (DVRP), new orders arrive when the working day plan is in progress. Thus, the routes must be reconfigured dynamically during the...
Research on the problem of delivery route optimization and selecting the appropriate delivery route is an effective way of enhancing the response speed of logistics process, improving service quality, lowering logistics costs and upgrading efficiency. The problem of logistics delivery route optimization is an NP hard problem. Therefore, the use of traditional optimization method is difficult to obtain...
Many distribution companies must deliver and pick up goods to satisfy customers. This problem is called the Vehicle Routing Problem with Mixed linehauls and Backhauls (VRPMB) which considers that some goods must be delivered from a depot to linehaul customers, while others must be picked up at backhaul customers to be brought to the depot. This paper studies an enriched version called Heterogeneous...
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