Bi-sided facility location problems: an efficient algorithm for k-centre, k-median, and travelling salesman problems

This study introduces a general framework, called Bi-sided facility location, for a wide range of problems in the area of combined facility location and routing problems such as locating test centres and designing the network of supermarkets. It is based on a multi-objective optimisation model to enhance the service quality which the clients...

Energy-Efficient Routing of a Multirobot Station: A Flexible Time-Space Network Approach

This paper investigates a novel routing problem of a multi-robot station in a manufacturing cell. In the existing literature, the objective is to minimize the cycle time or energy consumption separately. The routing problem considered in this paper aims to reduce the cycle time and energy consumption jointly for each robot while avoiding...

Optimization of Charging Strategies for Battery Electric Vehicles under Uncertainty

The comparably low driving ranges of battery electric vehicles (BEV) cause time-consuming recharging stops if long distances have to be covered. Thus, navigation systems not only have to compute routes leading from the BEV's current position to the destination, but also to plan recharging stops. This type of routing problem is often modeled...

A-DDPG: Attention Mechanism-based Deep Reinforcement Learning for NFV

The efficacy of Network Function Virtualization (NFV) depends critically on (1) where the virtual network functions (VNFs) are placed and (2) how the traffic is routed. Unfortunately, these aspects are not easily optimized, especially under time-varying network states with different quality of service (QoS) requirements. Given the importance of...

A Time-Space Network Model for Collision-free Routing of Planar Motions in a Multi-Robot Station

This article investigates a new collision-free routing problem of a multirobot system. The objective is to minimize the cycle time of operation tasks for each robot while avoiding collisions. The focus is set on the operation of the end-effector and its connected joint, and the operation is projected onto a circular area on the plane. We...

Routing of a multi-robot system using a Time-Space Network model

In this paper, we study the collision-free routing of a multi-robot system to complete given tasks in the shortest time. In a robotic assembly unit, several stations work serially and in parallel. In a station, multiple robots share the same workspace and face the challenge of minimizing the cycle time and avoiding collisions at the same time...

Exact formulation and comparison between the user optimum and system optimum solution for routing privately owned automated vehicles

The possibility of having driverless cars on the streets seems to be more real than ever. In this paper, we focus on developing exact methods that can determine the effects of privately owned automated vehicles (AVs) and how switching to those vehicles is going to change mobility in urban environments. The considered problem determines the...

The world according to MARP

In multi-agent route planning (MARP), there is a set of agents each with a start location and a destination location on a shared infrastructure, and the goal of each agent is to reach its destination in the shortest possible time, without coming into conflict (e.g. because of a collision) with any of the other agents. The MARP problem is...

Improving real-time train dispatching: Models, algorithms and applications

Traffic controllers monitor railway traffic sequencing train movements and setting routes with the aim of ensuring smooth train behaviour and limiting as much as existing delays. Due to the strict time limit available for computing a new timetable during operations, which so far is rather infeasible by using existing tools, railway traffic...

Rewriting the Sensor Network Abstraction Stack

Quality of Service Routing in the Internet. Theory, Complexity and Algorithms

The Internet consists of many network elements that direct packets on the correct path leading towards the destination. This process of finding and following a path to the destination is called routing. Routing is not infallible and packets may get lost: the current Internet cannot give any quality guarantees regarding the packets it transports....