References of "Limbourg, Sabine"
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See detailTSP model for electric vehicle deliveries, considering speed, loading and road grades
Bay, Maud ULg; Limbourg, Sabine ULg

Conference (2015, June 05)

The objective usually considered in sustainable transportation is to minimize pollution due to emissions, and equivalently energy consumption. Turning to electric mobility, pollution is related to ... [more ▼]

The objective usually considered in sustainable transportation is to minimize pollution due to emissions, and equivalently energy consumption. Turning to electric mobility, pollution is related to electricity production technology, not considered in this research; driving range is the major concern nowadays, due to the limited capacity of batteries and long recharge times . Maximizing the driving range or the level of energy (state of charge of the battery) at destination leads to consider the main factors of energy consumption which are : vehicle weight, engine efficiency and consumption models, drive speed and acceleration, drive pattern, road grade, and payload. We define the electric vehicle travelling salesman problem (EV-TSP) and the electric vehicle routing problem (E-VRP) based on the classical TSP and on the Pollution Routing Problem (PRP) and present models and preliminary results for those problems. [less ▲]

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See detailBRAIN TRAINS: Intermodal rail freight transport and hinterland connections A SWOT analysis to assess the Belgian rail practice
Troch, Frank; Vanelslander, Thierry; Belboom, Sandra ULg et al

Scientific conference (2015, May)

This paper focuses on transversal research of the role and influences of rail freight transport, as a part of intermodal transport in Belgium. A SWOT analysis of the current situation is conducted ... [more ▼]

This paper focuses on transversal research of the role and influences of rail freight transport, as a part of intermodal transport in Belgium. A SWOT analysis of the current situation is conducted, starting from the actual weak usage of this mode of transport. Five different fields have been identified, impacting the economy and society. Each field indicates critical internal strengths and weaknesses for intermodal rail transportation in Belgium, and identifies possible future developments and setbacks. A Delphi-like approach is used, including a heterogeneous panel of experts, discussing and validating the SWOT results. To prioritize the characteristics, a survey on the different SWOT elements is performed, asking the experts to rate each statement on its influence and likelihood of happening, indicating the level of uncertainty. [less ▲]

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See detailTSP model for electric vehicle deliveries, considering speed, loading and path slope.
Bay, Maud ULg; Limbourg, Sabine ULg

Conference (2015, April 17)

In the current Transport White Paper, the European Union presents a roadmap for a more competitive and sustainable European transport system. Concerning Urban Freight Transport, responsible for about a ... [more ▼]

In the current Transport White Paper, the European Union presents a roadmap for a more competitive and sustainable European transport system. Concerning Urban Freight Transport, responsible for about a quarter of CO2 emissions of the transport sector, one of the goals of the EU is to achieve essentially CO2-free city logistics in major urban centres by 2030 by developing and deploying new and sustainable fuels and propulsion systems. The gradual phasing out of ‘conventionally-fuelled’ vehicles from the urban environment contributes to reduce oil dependence, greenhouse gas emissions and local air and noise pollution. To meet European air quality standards, authorities of some major European cities have already introduced Low Emissions Zones where access to urban areas is limited to freight vehicles that meet certain emissions standards. Greater use of low-emission urban trucks based on electric, hydrogen and hybrid technologies would reduce air emissions, but also noise, letting to use road infrastructure more efficiently by making night deliveries and avoiding morning and afternoon peak periods. In addition to their role in the reduction of polluting emissions, the development of low-emission vehicles also allows to mitigate the dependence of the transportation sector to high fossil fuel prices. Electric vehicles have the potential to be powered by renewable energy sources such as wind and solar energy. However, weaknesses can be found in the limited capacity of the battery and the time needed to recharge, and consequently, the limited driving range of electric vehicle. The main sources for final energy consumption are the vehicle size and the engine characteristics, the load factor, the driving pattern, the gradient which represent the average topology of the country, the speed and the acceleration. To maximize the driving range, a routing model, which aims at minimizing the energy consumption, has to be developed. Our paper focus on the Electric Vehicle Traveling Salesman Problem (EV-TSP): given n cities, find the shortest tour, i.e., the shortest directed cycle containing all cities. The classical objective is to minimize the cost tour scheduling to fulfill delivery requests at each location. In this paper we consider the energy cost and we present an extension of the classical problem to minimize the remaining storage capacity of all electric vehicles at the destination node, knowing that there is no recharge operation on the tour. The objective function accounts not just for the travel distance but also on the load of the vehicle and on its speed while the energy consumption of the engine additionally depends on the path to travel, on the slope of the roads and on the vehicle specifications. Moreover, negative consumption that may happen due to regenerative breaking and kinetic energy capture on downhill paths is taken into consideration. Mathematical model is described and computational experiments are performed. [less ▲]

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See detailA mixed integer nonlinear programming bi-objective model for intermodal network design
Mostert, Martine ULg; Caris, An; Limbourg, Sabine ULg

Conference (2015, February 05)

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See detailThe impact of transport policies on railroad intermodal freight competitiveness – The case of Belgium
Santos, Bruno F.; Limbourg, Sabine ULg; Carreira, Joana Silva

in Transportation Research. Part D : Transport and Environment (2015), 34

This paper discusses the impact of three freight transport policies aiming to promote railroad intermodal transport in Europe, and examines the case of Belgium as a testing ground. These policies consist ... [more ▼]

This paper discusses the impact of three freight transport policies aiming to promote railroad intermodal transport in Europe, and examines the case of Belgium as a testing ground. These policies consist in subsidizing intermodal transport operations (such as in Belgium, to stimulate rail transport), internalizing external costs (as recommended by the European Union in order to foster cleaner modes), and adopting a system perspective when optimizing the location of inland intermodal terminals. The study proposes an innovative mixed integer intermodal freight location-allocation model based on hub-location theory and deals with non-linear transport costs in order to replicate economies of distance. Our analysis suggests that subsidizing has a significant impact on the volumes transported by intermodal transport, and, to a lesser extent, that optimizing terminal location increases the competitiveness of intermodal transport. On the other hand, according to our assumptions, internalizing external costs can negatively impact the promotion of intermodality. This finding indicates that innovative last-mile transports are needed in order to reduce the external impacts of drayage operations. [less ▲]

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See detailVehicle routing problems with loading constraints: State-of-the-art and future directions
Pollaris, Hanne; Braekers, Kris; Caris, An et al

in OR Spectrum (2015), 37(Issue 2), 297-330

Distributors are faced with loading constraints in their route planning, e.g.,multi-dimensional packing constraints, unloading sequence constraints, stability constraints and axle weight limits. Ignoring ... [more ▼]

Distributors are faced with loading constraints in their route planning, e.g.,multi-dimensional packing constraints, unloading sequence constraints, stability constraints and axle weight limits. Ignoring these constraints impairs planning and induces last-minute changes resulting in additional costs. Developing vehicle routing models incorporating loading constraints is critical to more efficient route planning. The last couple of years has seen a huge increase of contributions to this field of research with almost 60 % of these being published after 2009. Our contribution is twofold. First, we overview the recent developments in the literature on all vehicle types in which loading constraints play a key role (trucks, airplanes, ships, and automated guided vehicles), using a state-of-the-art classification scheme to identify the loading constraints considered in each article. Second, we identify research gaps and opportunities for future research. [less ▲]

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See detailCapacitated vehicle routing problem with sequence- based pallet loading and axle weight constraints
Pollaris, Hanne; Braekers, Kris; Caris, An et al

in EURO Journal on Transportation and Logistics (2014)

In this paper, we introduce and study the capacitated vehicle routing problem with sequence-based pallet loading and axle weight constraints. To the best of our knowledge, it is the first time that axle ... [more ▼]

In this paper, we introduce and study the capacitated vehicle routing problem with sequence-based pallet loading and axle weight constraints. To the best of our knowledge, it is the first time that axle weight restrictions are incorporated in a vehicle routing model. The aim of this paper is to demonstrate that incorporating axle weight restrictions in a vehicle routing model is possible and necessary for a feasible route planning. Axle weight limits impose a great challenge for transportation companies. Trucks with overloaded axles represent a significant threat for traffic safety and may cause serious damage to the road surface. Transporters face high fines when violating these limits. A mixed integer linear programming formulation for the capacitated vehicle routing problem with sequence-based pallet loading and axle weight constraints is provided. Results of the model are compared to the results of the model without axle weight restrictions. Computational experiments demonstrate that the model performs adequately and that the integration of axle weight constraints in vehicle routing models is required for a feasible route planning. [less ▲]

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See detailA Bi-Objective Location-Allocation Model for Intermodal Terminals
Mostert, Martine ULg; Caris, An; Limbourg, Sabine ULg

Conference (2014, July 18)

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See detailInventory-routing problem with pickups and deliveries of RTI in closed-loop supply chain
Iassinovskaia, Galina; Limbourg, Sabine ULg; Riane, Fouad

Conference (2014, July 17)

Reducing environmental impact, related regulations and potential for operational benefits are the main reasons why companies share their Returnable Transport Items (RTIs) among different partners of a ... [more ▼]

Reducing environmental impact, related regulations and potential for operational benefits are the main reasons why companies share their Returnable Transport Items (RTIs) among different partners of a closed-loop supply chain. This research deals with an inventory-routing problem with pickups and deliveries of RTIs. A mixed-integer linear program is developed and tested on small instances. To handle realistic large size problems, a clustering algorithm is coupled with a simulation model. This hybrid heuristic allows assessing the benefits of information and RTIs sharing among partners. [less ▲]

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See detailIntegrating axle weight restrictions in a two-dimensional vehicle routing problem with sequence based loading
Pollaris, Hanne; Braekers, Kris; Caris, An et al

Scientific conference (2014, June)

A mixed integer linear programming model for a two-dimensional capacitated vehicle routing problem (2L-CVRP) with sequence based loading and axle weight restrictions is provided. To the authors’ knowledge ... [more ▼]

A mixed integer linear programming model for a two-dimensional capacitated vehicle routing problem (2L-CVRP) with sequence based loading and axle weight restrictions is provided. To the authors’ knowledge, it is the first time that axle weight restrictions are incorporated in a VRP. Axle weight limits impose a great challenge for transportation companies. Trucks with overloaded axles represent a significant threat for traffic safety and may cause serious damage to the road surface. Transporters face high fines when violating these limits. The problem is based on a real-world problem from a Belgian logistics service provider. The demand of the customers consists of europallets. Pallets can be placed in two horizontal rows inside the vehicle. No vertical stacking is allowed. The center of gravity of the pallets inside the vehicle is calculated to determine the axle weights. Results of the model are compared to results of a 2L-CVRP with sequence based loading without axle weight restrictions. Numerical experiments demonstrate that the model performs adequately and that the integration of axle weight constraints in vehicle routing models is necessary for a feasible route planning. [less ▲]

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See detailHow to locate intermodal terminals for achieving economic and environmental competitiveness?
Mostert, Martine ULg; Limbourg, Sabine ULg

Conference (2014, April 25)

Europe has a strong commitment to the development of competitive and sustainable transportation. An intermediate objective cited in the “White Paper” is to shift 30% of 300 km and above road freight ... [more ▼]

Europe has a strong commitment to the development of competitive and sustainable transportation. An intermediate objective cited in the “White Paper” is to shift 30% of 300 km and above road freight transportation to more environmentally-friendly modes of transport such as rail and water by 2030. Improving and expanding the intermodal network is one way to achieve this goal. However, intermodal transport requires intermodal terminals where the transfer from one mode to another can occur. The location of those terminals is of strategic importance for the competitiveness of intermodal transport. The objective of this paper is therefore to develop a network design model which allows the optimal location of intermodal terminals to be determined, subject to both economic and environmental efficiency. Three possible combinations are considered: (i) Road-only, (ii) Intermodal transport using road (drayage) and rail (long-haul) and (iii) Intermodal transport using road (drayage) and inland waterways (long-haul). External costs are also included in the analysis, i.e. costs that are generated by an economic agent but supported by other agents of the society. This strategy is in line with the willingness of Europe to internalize external costs. The developed model can be used to test how modal split is influenced by the undertaken policies, such as internalizing external costs in the transportation costs. Tests are carried out on the case study of Belgium. [less ▲]

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See detailLogistics hub: the case of Liège
Limbourg, Sabine ULg; Mostert, Martine ULg; Paquay, Célia ULg

Conference (2014, April 24)

A logistics hub can be defined as a specific area where all the activities relating to transport, logistics and goods distribution are carried out. With its central location in Europe, highly developed ... [more ▼]

A logistics hub can be defined as a specific area where all the activities relating to transport, logistics and goods distribution are carried out. With its central location in Europe, highly developed infrastructures, airport and inland terminals, the region of Liège claims to be a logistics hub. This paper applies a strategic decision model based on seven relevant criteria (infrastructure, proximity to market, land availability, government and industry support, labour supply, origin/destination distances and congestion) to assess the efficiency of the logistics hub of the region of Liège. Two SWOT analyses are performed in parallel to evaluate the positions of Liège Airport and of the inland freight hub, Trilogiport, in relation to their own performances and the competition. The two main development factors of inland freight hubs are considered: the possibility of modal shift from road transport to more environmentally friendly transportation modes and the avoidance of the congestion of the two seaport areas of Antwerp and Rotterdam. This article concludes by highlighting that the bid of the region of Liège and its characteristics should contribute to a more efficient intermodal transport in Europe, helping to boost the distribution of products, and at the same time, encourage the reduction of greenhouse gas emissions. However, the development of Liège as an inland freight hub depends on its ability to generate a critical mass, notably thanks to the local businesses, in order to realise economies of scale. [less ▲]

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See detailA Mixed Integer Programming formulation for the three dimensional bin packing problem deriving from an air cargo application
Paquay, Célia ULg; Schyns, Michael ULg; Limbourg, Sabine ULg

in International Transactions in Operational Research (2014)

The present paper looks into the problem of optimising the loading of boxes into containers. The goal is to minimise the unused volume. This type of problem belongs to the family of Multiple Bin Size Bin ... [more ▼]

The present paper looks into the problem of optimising the loading of boxes into containers. The goal is to minimise the unused volume. This type of problem belongs to the family of Multiple Bin Size Bin Packing Problems. The approach includes an extensive set of constraints encountered in real-world applications in the three-dimensional case: the stability, the fragility of the items, the weight distribution and the possibility to rotate the boxes. It also includes the specific situation in which containers are truncated parallelepipeds. This is typical in the field of air transportation. While most papers on cutting and packing problems describe ad-hoc procedures, this paper proposes a mixed integer linear program. The validity of this model is tested on small instances. [less ▲]

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See detailIntegration of inland waterway transport in the intermodal supply chain: a taxonomy of research challenges
Caris, An; Limbourg, Sabine ULg; Macharis, Cathy et al

in Journal of Transport Geography (2014), 41

This paper identifies research opportunities which will enable the further integration of inland waterway transport in the intermodal supply chain. Intermodal transport may be interpreted as a chain of ... [more ▼]

This paper identifies research opportunities which will enable the further integration of inland waterway transport in the intermodal supply chain. Intermodal transport may be interpreted as a chain of actors who supply a transport service. Inland navigation can play a crucial role in increasing supply chain service performance. A first group of research challenges lies in the evolving relationship between transport geography and logistics activities. The next set of research challenges has the objective to encourage efficient operations in IWT: development of a system wide model for IWT, integration of operational planning systems and analysis of bundling networks. A third group of research efforts is directed towards shippers and consignees who use the intermodal transport chain to send or receive their goods: further development of models that integrate intermodal transport decisions with supply chain decisions and creation of green supply chains. A fourth cluster of research challenges concerns the problem domain of external cost calculations. Finally detailed time series data on freight transport should be collected to support these future research tracks? [less ▲]

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See detailA constructive heuristic for the three dimensional Bin Packing Problem with transportation constraints
Paquay, Célia ULg; Schyns, Michael ULg; Limbourg, Sabine ULg

Conference (2014)

The aim of this work is to propose a Relax-And-Fix heuristic to build a good initial solution to the 3D BPP. First, a mathematical formulation has been developed taking into account several types of ... [more ▼]

The aim of this work is to propose a Relax-And-Fix heuristic to build a good initial solution to the 3D BPP. First, a mathematical formulation has been developed taking into account several types of constraints such as the stability and fragility of the boxes to pack, their possibility to rotate, the weight distribution inside the bins and their special shapes. Since this model contains a lot of integer variables, we have decided to apply the Relax-and-Fix method. We have selected several sets of variables to be the branching variables and carried out some tests. [less ▲]

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See detailClimatological influences on inland waterway transport capacity
Cools, Mario ULg; Limbourg, Sabine ULg

Conference (2014)

Climate change may affect inland waterway transport through disturbances in waterway hydrology: longer periods with strong water swells and drops. To allow fully loaded barges, the water level must be ... [more ▼]

Climate change may affect inland waterway transport through disturbances in waterway hydrology: longer periods with strong water swells and drops. To allow fully loaded barges, the water level must be neither too high (limited air draught) nor too low (limited draught). Therefore, the water level impacts the load factor of barges and thus the transportation costs. Moreover, in winter, ice jams can paralyze inland waterway traffic on the river. In this paper, the effect of various climatological changes on the capacity of inland waterway in terms of barge transport is examined. The paper focusses on the development of a methodology for assessing the sensitivity of inland waterway systems to climatological changes and takes into account an experts' opinion survey that provides insight into the perceived likelihood of the different scenarios that are investigated. The analysis focusses on the inland waterway systems in Belgium, which has the second highest density of European inland waterways. It enables the integration of inland waterway transport in the intermodal supply chain. The results are related to investment planning and management in inland waterways transport. They are intended to be interesting to researchers and to inland waterways actors developing intermodal transport as well. [less ▲]

Detailed reference viewed: 57 (4 ULg)