13,648 research outputs found
Erratum:Branch and Price for the Time-Dependent Vehicle Routing Problem with Time Windows (Transportation Science (2024) 58:5 (919-924) DOI: 10.1287/trsc.11200445)
Full text linkThe aim of this erratum is to correct an error in the computer implementation of the algorithm proposed by Dabia, Ropke, and van Woensel [Dabia S, Ropke S, van Woensel T (2013) Branch and price for the time-dependent vehicle routing problem with time windows. Transportation Sci. 47(3):295–454]. Section 6, “Computational Results,” from the original paper is rewritten to reflect the corrected implementation, the new computational setup, and the updated results.The aim of this erratum is to correct an error in the computer implementation of the algorithm proposed by Dabia, Ropke, and van Woensel [Dabia S, Ropke S, van Woensel T (2013) Branch and price for the time-dependent vehicle routing problem with time windows. Transportation Sci. 47(3):295–454]. Section 6, “Computational Results,” from the original paper is rewritten to reflect the corrected implementation, the new computational setup, and the updated results
From managing urban freight to smart city logistics networks
No full textWe present City Logistics by taking a systemic view, describing its main components and elements, as an emerging field of study with wide and significant social and economic impact. We then review contributions and identify some of the challenges that City Logistics raises, particularly for Operations Research and Transportation Science. The focus is on the network design issues relative to the system structure and services
A competitive solution for cooperative truckload delivery
Full text linkThis paper introduces a solution for gain sharing in consortia of logistic providers where joint planning of truckload deliveries enables the reduction of empty kilometers. The highly competitive nature of freight transport markets necessitates solutions that distinguish among the logistics providers based on their characteristics, even in situations with two players only. We introduce desirable properties in these situations and propose a solution that satisfies such properties. By comparing the existing solutions against the introduced properties we demonstrate the advantages of our proposed solution
On characterization of the core of lane covering games via dual solutions
Full text linkThe lane covering game (LCG) is a cooperative game where players cooperate to reduce the cost of cycles that cover their required lanes on a network. We discuss the possibilities/impossibilities of a complete characterization of the core via dual solutions in LCGs played among a collection of shippers, each with a number of service require-ments along some lanes, and show that such a complete characterization is possible if each shipper has at most one service requirement
De scheiding van Maas en Waal onder verlegging van de uitmonding der Maas naar den Amer
No full textHistorie van overstromingen langs de Maas, de Beerse Maas en de Baardwijkse Overlaat. Verbeteringsplannen van Leemans, Schebbele Nolthenius en C.W. Lely. Uiteindelijke plan en uitvoeringswet. Kosten vande plannen. Uitevoerde werken: riviervan Heleind-Dongemond, normalisering van de Amer, verruiming Heusdens kanaal. Bruggen en veren. Afwateringsvoorzieningen (gemalen, suatiesluizen). Sluiting van de Heerewaardense Overlaat, verhoging van de Waaldijken. Afsluiting van de Maas bij Andel. De Dommel en de Dieze. Bijkomende werken. Deze pdf is samengesteld uit scans van verschillende exemplaren van het rapport. Er is een aparte pdf met de platen 1 t/m5. Plaat 6 is opgenomen in twee versies, als afzonderlijke bladen (zoals uitgegeven) en als één samengestelde kaart van het gehele gebied. Administratieve regelen, Nacalculalatie van de kosten. Waterstanden.Bergsche Maa
Nieuwe Langendijk Delft: Bouwhistorisch en archeologisch onderzoek van de panden 22 t/m 28, deel I, beschrijving van de onderzoeksresultaten
No full textHet voor u liggende in drie deeltjes gebundelde pak papier is het verslag van een bouwhistorisch en archeologisch onderzoeK op de locatie Nieuwe Langendijk 22 t/m 28 - Trompetstraat 31 te Delft. Het onderzochte terrein is eigendom van de Delftse Katholieke Stichting voor Bejaardenzorg (DKSB). Het veldwerk van het onderzoek betrof de periode 10 februari t/m 6 augustus 1982, met uitzondering van de eerste weken van juliArchitectureArchitectur
Analysis of travel times and CO2 emissions in time-dependent vehicle routing
No full textDue to the growing concern over environmental issues, regardless of whether companies are going to voluntarily incorporate green policies in practice, or will be forced to do so in the context of new legislation, change is foreseen in the future of transportation management. Assigning and scheduling vehicles to service a pre-determined set of clients is a common distribution problem. Accounting for time-dependent travel times between customers, we present a model that considers travel time, fuel, and CO2 emissions costs. Specifically, we propose a framework for modeling CO2 emissions in a time-dependent vehicle routing context. The model is solved via a tabu search procedure. As the amount of CO2 emissions is correlated with vehicle speed, our model considers limiting vehicle speed as part of the optimization. The emissions per kilometer as a function of speed are minimized at a unique speed. However, we show that in a time-dependent environment this speed is sub-optimal in terms of total emissions. This occurs if vehicles are able to avoid running into congestion periods where they incur high emissions. Clearly, considering this trade-off in the vehicle routing problem has great practical potential. In the same line, we construct bounds on the total amount of emissions to be saved by making use of the standard VRP solutions. As fuel consumption is correlated with CO2 emissions, we show that reducing emissions leads to reducing costs. For a number of experimental settings, we show that limiting vehicle speeds is desired from a total cost perspective. This namely stems from the trade-off between fuel and travel time costs. © 2012 Production and Operations Management Society
Gain-sharing in urban consolidation centers
Full text linkUrban consolidation centers provide the logistical infrastructure for cooperation among less-than-truckload carriers with contiguous destinations. The rising number of initiatives to establish and operate urban consolidation centers and their low success rates signal the need for better mechanisms to manage cooperation in this context. We introduce and study cooperative situations comprising a set of carriers with time sensitive deliveries who can consolidate their cargo to obtain savings. We introduce the class of Dispatch Consolidation (DC) games and search for ways to fairly allocate the obtained savings among the participating carriers. When delivery capacities are not restrictive, i.e. when waiting costs trigger truck dispatches, we show that stable allocations in the core always exist and can, in their entirety, be found by solving a compact linear program. With restrictive capacities, however, the core of a DC game may become empty. We introduce the notion of component-wise core for DC games to preserve stability first and foremost among the carriers whose deliveries are dispatched together in the chosen optimal solutions. The novelty of our approach is to link the stability requirements of an allocation rule with the structure of selected solutions for the underlying optimization problems. We characterize the component-wise cores of DC games, prove their non-emptiness, and suggest proportionally calculated allocations therein. Finally, we discuss a refinement of component-wise core allocations that minimizes envy among the carriers who are dispatched separately
The time-dependent pollution-routing problem
Full text linkThe Time-Dependent Pollution-Routing Problem (TDPRP) consists of routing a fleet of vehicles in order to serve a set of customers and determining the speeds on each leg of the routes. The cost function includes fuel, emission and driver costs, taking into account traffic congestion which, at peak periods, significantly restricts vehicle speeds and increases emissions. We describe an integer linear programming formulation of the TDPRP and provide illustrative examples to motivate the problem and give insights about the tradeoffs it involves. We also provide an analytical characterization of the optimal solutions for a single-arc version of the problem, identifying conditions under which it is optimal to wait idly at certain locations in order to avoid congestion and to reduce the cost of emissions. Building on these analytical results we describe a departure time and speed optimization algorithm on a fixed route. Finally, using benchmark instances, we present results on the computational performance of the proposed formulation and on the speed optimization procedure
- …
