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The Vehicle Routing Problem (VRP) is a well-known management problem in large enterprises' logistic departments; in fact, it is classified as a combinatorial problem, where customers of known demands are supplied by one or several depots. Several realistic constraints are related to the vehicle routing problem; and thus, much time is needed to solve this problem in a deterministic way. The purpose...
Capacitated vehicle routing problem with pickups and deliveries (CVRPPD) is one of the most challenging combinatorial optimization problems which include goods delivery/pickup optimization, vehicle number optimization, routing path optimization and transportation cost minimization. The conventional particle swarm optimization (PSO) is difficult to find an optimal solution of the CVRPPD due to its...
We introduce an improved intelligent water drops (IIWD) algorithm as a new swarm-based nature inspired algorithm to solve capacitated vehicle routing problem. IIWD algorithm introduces new adjustments and features that help to optimize the VRP problem with higher efficiency. We reinforce this algorithm to have satisfactory consequences in controlling the balance between diversification and intensification...
The Vehicle Routing Problem with Time Windows (VRPTW) is a well known NP-Hard combinatorial optimization problem and it has received a lot of attention in the literature. In this problem, a fleet of identical vehicles must leave the depot, supply all costumers demands, and return to the depot, at minimum cost, without violating the capacity of the vehicles as well as the time window specified by each...
Vehicle routing is considered the basic issue in distribution management. In real-world problems, customer demand for some commodities increases on special situations. On the one hand, one of the factors that are very important for customers is the timely delivery of the demanded commodities. In this research, customers had several different kinds of demands. Therefore, a new routing model was introduced...
Based on the research on Vehicle Routing Problems (VRP), vehicle scheduling and operating work can be more rational, which consequently reduces the logistical cost on the condition of meeting the timeliness requirement of emergency logistics. In this paper, we give an analysis of the characteristics of VRP in emergency logistics. According to the practical situations of VRP, an improved genetic algorithm...
Vehicle Routing Problem (VRP) is a famous combinatorial optimization problem and it has been extended to a multi-objective optimization perspective. This paper targets solving VRP with stochastic demand (VRPSD) under the constraints of available time window and vehicle capacity. The objective of the problem is to simultaneously minimize total travelling distance and total drivers' remuneration. This...
The Capacitated Vehicle Routing Problem (CVRP) is a well-known NP-hard problem of importance to real life applications such as transportation and logistics. The CVRP finds the best set of paths between a specific number of customers to deliver goods by a number of vehicles with a fixed capacity. In this paper, we apply a new nature inspired optimization algorithm called Intelligent Water Drops (IWD)...
Coal mine materials delivery process has the following characteristics: (1) Depot and warehouse are located in different places; (2) Dangerous materials include explosives and detonators which cannot be mixed together for delivery; (3) There is no desired time window, but urgency for demand. Our objective aims at minimizing the distribution cost. For dangerous materials delivery process, we build...
Thi s paper presents an enhanced version of Ant Colony Optimization (ACO) for solving a variant of the Vehicle Routing Problem (VRP), which is utilized for Unmanned Aerial Vehicle (UAV) task allocation and route planning. The extended VRP incorporates multiple UAVs, collision avoidance between intersecting routes, and the possibility of loitering between tasks. The ACO adopts a multi-colony approach...
The vehicle routing problem with time windows (VRPTW) is investigated in this paper. The constraints of vehicle's capacity and the time windows are considered. Based on the principles of the intelligent water drops, a fast and efficient intelligent water drops algorithm for solving the VRPTW is designed. Simulation results show that we can find the global optimal solution of VRPTW with high probability...
This article describes an exact method based on a Branch & Cut algorithm for the multi-region vehicle routing problem in large quantities by a heterogeneous fleet of vehicles. Test results on different problem instances are presented after have been solved by CPLEX.
This paper investigates the vehicle routing problem (VRP) under multi-objective constraints. More specifically, we consider the distance, fixed cost, time, together with risk simultaneously. To get a quicker and more accurate solution, several improvements are proposed in applying GA for optimization search. Practical test confirms the effectiveness of the proposed method.
Recommended patrol routes can be used by organizations such as police agencies, emergency medical responders, and taxi services whose agents patrol roadway segments at proper times to assist or deter their target events. The creation of optimal complementary patrol routes for multiple agents targeting temporal event hotspots and minimizing travel distance is an NP-hard combinatorial problem that belongs...
This paper presents an improved scheme for the vehicle routing problems with time windows based on ant colony optimization algorithm. The new scheme makes the change of heuristic message fast and speeds the convergence process by improving updating method of global pheromone and visibility strategy. Simulation results from eight groups of vehicle transportation case show that the new scheme performs...
In order to achieve cost efficiency, customer satisfaction and also to concentrate on core business operations, many manufacturing firms are outsourcing their logistics activities to third party logistics (3PLs) provider. Reverse logistics is one type of logistics in which used products or end-of-life products are collected from the customers/retailers and send for reuse, refurbishing, recycling and/or...
The vehicle routing problem is a classical NP (Non-deterministic Polynomial) problem, and it is usually difficult to obtain the satisfied solution by the traditional method. On the basis of analysis of the existing genetic algorithm, the vehicle routing problems is solved through the improved mutation operator and the genetic algorithm of natural number coding scheme. Experiment result indicates that...
Based on traditional vehicle routing problem, grain logistics vehicle routing problem with time windows and the characteristics of grain logistics are fully considered in this paper. A model for grain logistics VRPTM was established, where the aim is to complete the maximum tasks with minimum cost. A PSO algorithm is proposed to solve the grain logistics VRPTW, the comparative experiments were made...
We describe a hybrid iterated density estimation evolutionary algorithm with 2-opt local search to determine the specific assignment of each tour to a private vehicle (internal fleet) or to an outside carrier (external fleet). Experimental results show that this method is effective, allowing the discovery of new best solutions for some well-known benchmarks.
Vehicle routing problem with time windows (VRPTW) is an NP-complete optimization problem. The objective of VRPTW is to use a fleet of vehicles with specific capacity to serve a number of customers with fixed demand and time window constraints. A hybrid ant colony system (DSACA-VRPTW) is proposed to solve this problem. Firstly, each antpsilas solution might be improved by dynamic sweep algorithm which...
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