Search results for " Programming"
showing 10 items of 1616 documents
A Branch-and-Cut Algorithm for the Single Truck and Trailer Routing Problem with Satellite Depots
2016
International audience; In the single truck and trailer routing problem with satellite depots (STTRPSD), a truck with a detachable trailer based at a main depot must serve the demand of a set of customers accessible only by truck. Therefore, before serving the customers, it is necessary to detach the trailer in an appropriate parking place (called either a satellite depot or a trailer point) and transfer goods between the truck and the trailer. This problem has applications in milk collection for farms that cannot be reached using large vehicles. In this work we present an integer programming formulation of the STTRPSD. This formulation is tightened with several families of valid inequaliti…
Mathematical models for multicontainer loading problems
2017
Abstract This paper deals with the problem of a distribution company that has to serve its customers by putting first the products on pallets and then loading the pallets onto trucks. We approach the problem by developing and solving integer linear models. We start with basic models, that include the essential features of the problem, such as respecting the dimensions of the truck, and not exceeding the total weight capacity and the maximum weigh capacity on each axle. Then, we add progressively new conditions to consider the weight and volume of pallet bases and to include other desirable features for the solutions to be useful in practice, such as the position of the center of gravity and…
Branch-and-Price-and-Cut for the Active-Passive Vehicle-Routing Problem
2018
This paper presents a branch-and-price-and-cut algorithm for the exact solution of the active-passive vehicle-routing problem (APVRP). The APVRP covers a range of logistics applications where pickup-and-delivery requests necessitate a joint operation of active vehicles (e.g., trucks) and passive vehicles (e.g., loading devices such as containers or swap bodies). The objective is to minimize a weighted sum of the total distance traveled, the total completion time of the routes, and the number of unserved requests. To this end, the problem supports a flexible coupling and decoupling of active and passive vehicles at customer locations. Accordingly, the operations of the vehicles have to be s…
Suspension system performance optimization with discrete design variables
2013
Published version of an article in the journal: Structural and Multidisciplinary Optimization. Also available from the publisher at: http://dx.doi.org/10.1007/s00158-013-0888-7 Suspension systems on commercial vehicles have become an important feature meeting the requirements from costumers and legislation. The performance of the suspension system is often limited by available catalogue components. Additionally the suspension performance is restricted by the travel speed which highly influences the ride comfort. In this article a suspension system for an articulated dump truck is optimized in sense of reducing elapsed time for two specified duty cycles without violating a certain comfort th…
Mathematical models for Multi Container Loading Problems with practical constraints
2019
Abstract We address the multi container loading problem of a company that serves its customers’ orders by building pallets with the required products and loading them into trucks. The problem is solved by using integer linear models. To be useful in practice, our models consider three types of constraints: geometric constraints, so that pallets lie completely inside the trucks and do not overlap; weight constraints, defining the maximum weights supported by a truck and by each axle, as well as the position of the centre of gravity of the cargo; and dynamic stability constraints. These last constraints forbid empty spaces between pallets to avoid cargo displacement when the truck is moving, …
The Multi-period Multi-trip Container Drayage Problem with Release and Due Dates
2021
Abstract The Container Drayage Problem (CDP) aims at routing a fleet of trucks, based at a common terminal, to serve customers while minimizing the total travel distance. Each trip starts from and ends at the terminal, and handles a subset of customers. Each customer requires either that a container is picked up or delivered. We introduce a more realistic variant, i.e., the Multi-trip Multi-period CDP with Release and Due Dates (MM-CDP-RDD), in which the planning horizon is composed of several periods (days). On each day, each truck may perform more than one trip respecting the Release and Due Dates (RDD) associated with customer services, corresponding to the first and the last day on whic…
Adaptation of microphysical and chemical instrumentation to the airborne measuring platform Iljushin I1-18 ‘Cyclone’ and flight regime planning durin…
1997
Abstract In 1993 the joint Russian-German Research Project ‘Arctic Haze’ started (see the Introduction and editorial note of this issue, by Jaenicke, Khattatov, Jaeschke and Leiterer). Besides CAO, four German groups were involved. To the present three airborne measuring campaigns have been performed. In total 251 h of flight within altitudes up to 8.7 km were flown in the western and eastern part of the arctic leading to a comprehensive set of data of the northern arctic hemisphere. The measurements were conducted aboard the Russian research aircraft I1-18 ‘Cyclone’ which was used by CAO in numerous scientific projects mainly in the former USSR. This 4 engined turboprop aircraft is well eq…
A Measure of Trust: The Italian Regional Divide in a Latent Class Approach
2017
Social differences within countries may partly explain the lack of economic convergence and the persistence of regional disparities. The case of Italy is emblematic: economic gap between North and South remains at high levels with large differences in social capital and in trust. In this paper, we use the micro data from the ISTAT “Aspects of Daily Life” Survey to build a measure of “trust in others” and a measure of “trust in institutions” through a latent class model to attribute a trust score to the Italian households and the Italian regions and, in this way, to add elements of knowledge useful to policies. Our measures confirm a persistent territorial divide although the regional mappin…
Domēnspecifisku rīku konfigurācijas valoda un tās realizācija
2014
Promocijas darbā ir izstrādāts konfigurators plaša profila DSML rīku definēšanai. Konfigurators balstās uz ideju, ka DSML definīciju var uzdot ar universālu metamodeli (UML klašu diagrammas formā), kura pēc tam konfiguratorā tiek apstrādāta, lai nodrošinātu rīka darbību. Turklāt nestandarta gadījumiem, kad esošās metamodeļa iespējas ir nepietiekošas, metamodelī ir realizēts paplašinājuma punktu mehānisms, kas ļauj pievienot rīkam specifiski transformāciju valodā noprogrammētu funkcionalitāti. Izstrādātais konfigurators ir pārbaudīts vairākos praktiskos lietojumos un apliecinājis savu efektivitāti.
UML Style Graphical Notation and Editor for OWL 2
2010
OWL is becoming the most widely used knowledge representation language. It has several textual notations but no standard graphical notation apart from verbose ODM UML. We propose an extension to UML class diagrams (heavyweight extension) that allows a compact OWL visualization. The compactness is achieved through the native power of UML class diagrams extended with optional Manchester encoding for class expressions thus largely eliminating the need for explicit anonymous class visualization. To use UML class diagram notation we had to modify its semantics to support Open World Assumption that is central to OWL. We have implemented the proposed compact visualization for OWL 2 in a UML style …