Multi-depot Location-Routing Problem (MDLRP) is about finding the optimal number and locations of depots while allocating customers to depots and determining vehicle routes to visit all customers. In this study we propose a nested Lagrangian relaxation-based method for the discrete uncapacitated MDLRP. An outer Lagrangian relaxation embedded in subgradient optimization decomposes the parent pro...

In this paper I propose a Branch-and-Price algorithm for the solution of the Vehicle Routing Problem with Time Windows where the pricing subproblem, the resource constrained elementary shortest path problem (RCESPP), is solved to optimality. 1. Problem formulation The Vehicle Routing Problem with Time Windows (VRPTW) is defined over a graph G = (V, A) where V = {0, . . . , n} is the node set in...

The Capacitated Arc Routing Problem with Refill Points (CARP-RP) is a new variant of the Capacitated Arc Routing Problem (CARP). In a CARP situation, the vehicle servicing arcs has a finite capacity, and hence has to return to the depot or a secondary station to be refilled (or emptied). In contrast, in the CARP-RP, the vehicle servicing arcs must be refilled on the spot by using a second vehic...

New government regulations and incentives promote the deployment of commercial electric vehicles to reduce carbon emissions from gasoline-fueled vehicles. For (CEVs) operating in a fleet, charging processes are often performed at depot where they begin end their daily driving cycles, as well public stations on routes. With large penetration CEVs depots, simultaneous increases peak demand, which...

We consider a special routing problem which has a variety of practical applications. In a graph-theoretic context it is known as the Capacitated Chinese Postman Problem. Given an undirected network in which the demand is located on edges, the goal is to determine a least-cost schedule of routes. The route demands, which must not exceed the vehicle capacity, are serviced by a fleet of vehicles w...

The aim of this paper is to introduce a hybrid two-phase algorithm called SW+ ASelite for solving the MTSP which can be explained as the problem of designing collection of routes from one depot to a number of customers subject to side constraints. At the first stage, the MTSP is solved by the sweep algorithm, and at the second stage, the Elite Ant Colony Optimization ( ASelite ) and 3-opt local...

In this work, the Multi-Depot Green VRP with Pickups and Deliveries (MDGVRP-PD) is studied. It a routing optimization problem in which objective to construct set of vehicle routes considering multiple depots one-to-one pickup delivery operations that minimize emissions through fuel consumption, depends on weight travel distance. problems, goods must be transported between single origin its asso...

T fleet size and mix vehicle routing problem with time windows (FSMVRPTW) is the problem of determining, at the same time, the composition and the routing of a fleet of heterogeneous vehicles aimed to serve a given set of customers. The routing problem requires us to design a set of minimum-cost routes originating and terminating at a central depot and serving customers with known demands, with...

Due to drops in orders and decreasing production rates, demand is declining seriously in many logistic sectors like e.g. air cargo, ship and less-than-truckload (LTL) transports. Hence, logistic companies are looking for new ways to improve their transportation network efficiency. On the operational level, costs depend mainly on planned delivery tours. In our current research project KolOptNet1...

The Multi-Depot Vehicle Routing Problem (MDVRP) is an important variant of the classical Vehicle Routing Problem (VRP), where the customers can be served from a number of depots. This paper introduces a cooperative coevolutionary algorithm to minimize the total route cost of the MDVRP. Coevolutionary algorithms are inspired by the simultaneous evolution process involving two or more species. In...