33 Search Results for "Clausen, Uwe"


Document
09261 Abstracts Collection – Models and Algorithms for Optimization in Logistics

Authors: Cynthia Barnhart, Uwe Clausen, Ulrich Lauther, and Rolf H. Möhring

Published in: Dagstuhl Seminar Proceedings, Volume 9261, Models and Algorithms for Optimization in Logistics (2009)


Abstract
From June 21 to June 26, 2009 the Dagstuhl Seminar Perspectives Workshop 09261 ``Models and Algorithms for Optimization in Logistics '' was held in Schloss Dagstuhl~--~Leibniz Center for Informatics. During the seminar, several participants presented their current research, and ongoing work and open problems were discussed. Abstracts of the presentations given during the seminar as well as abstracts of seminar results and ideas are put together in this paper. The first section describes the seminar topics and goals in general. Links to extended abstracts or full papers are provided, if available.

Cite as

Cynthia Barnhart, Uwe Clausen, Ulrich Lauther, and Rolf H. Möhring. 09261 Abstracts Collection – Models and Algorithms for Optimization in Logistics. In Models and Algorithms for Optimization in Logistics. Dagstuhl Seminar Proceedings, Volume 9261, pp. 1-18, Schloss Dagstuhl – Leibniz-Zentrum für Informatik (2009)


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@InProceedings{barnhart_et_al:DagSemProc.09261.1,
  author =	{Barnhart, Cynthia and Clausen, Uwe and Lauther, Ulrich and M\"{o}hring, Rolf H.},
  title =	{{09261 Abstracts Collection – Models and Algorithms for Optimization in Logistics }},
  booktitle =	{Models and Algorithms for Optimization in Logistics},
  pages =	{1--18},
  series =	{Dagstuhl Seminar Proceedings (DagSemProc)},
  ISSN =	{1862-4405},
  year =	{2009},
  volume =	{9261},
  editor =	{Cynthia Barnhart and Uwe Clausen and Ulrich Lauther and Rolf H. M\"{o}hring},
  publisher =	{Schloss Dagstuhl -- Leibniz-Zentrum f{\"u}r Informatik},
  address =	{Dagstuhl, Germany},
  URL =		{https://drops.dagstuhl.de/entities/document/10.4230/DagSemProc.09261.1},
  URN =		{urn:nbn:de:0030-drops-21915},
  doi =		{10.4230/DagSemProc.09261.1},
  annote =	{Keywords: Logistics, optimization, transport}
}
Document
09261 Executive Summary – Models and Algorithms for Optimization in Logistics

Authors: Cynthia Barnhart, Uwe Clausen, Ulrich Lauther, and Rolf H. Möhring

Published in: Dagstuhl Seminar Proceedings, Volume 9261, Models and Algorithms for Optimization in Logistics (2009)


Abstract
From June 21 to June 26, 2009, the Dagstuhl Seminar 09261 on Models and Algorithms for Optimization in Logistics was held in the International Conference and Research Center (IBFI), Schloss Dagstuhl. During the seminar, several participants presented their current research, and ongoing work and open problems were discussed. Abstracts of the presentations given during the seminar as well as abstracts of seminar results and ideas are put together in this paper. The first section describes the seminar topics and goals in general. Links to extended abstracts or full papers are provided, if available.

Cite as

Cynthia Barnhart, Uwe Clausen, Ulrich Lauther, and Rolf H. Möhring. 09261 Executive Summary – Models and Algorithms for Optimization in Logistics. In Models and Algorithms for Optimization in Logistics. Dagstuhl Seminar Proceedings, Volume 9261, pp. 1-2, Schloss Dagstuhl – Leibniz-Zentrum für Informatik (2009)


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@InProceedings{barnhart_et_al:DagSemProc.09261.2,
  author =	{Barnhart, Cynthia and Clausen, Uwe and Lauther, Ulrich and M\"{o}hring, Rolf H.},
  title =	{{09261 Executive Summary – Models and Algorithms for Optimization in Logistics}},
  booktitle =	{Models and Algorithms for Optimization in Logistics},
  pages =	{1--2},
  series =	{Dagstuhl Seminar Proceedings (DagSemProc)},
  ISSN =	{1862-4405},
  year =	{2009},
  volume =	{9261},
  editor =	{Cynthia Barnhart and Uwe Clausen and Ulrich Lauther and Rolf H. M\"{o}hring},
  publisher =	{Schloss Dagstuhl -- Leibniz-Zentrum f{\"u}r Informatik},
  address =	{Dagstuhl, Germany},
  URL =		{https://drops.dagstuhl.de/entities/document/10.4230/DagSemProc.09261.2},
  URN =		{urn:nbn:de:0030-drops-21752},
  doi =		{10.4230/DagSemProc.09261.2},
  annote =	{Keywords: Logistics, optimization, transport}
}
Document
A Network Design Problem

Authors: Anton J. Kleywegt, Jinpyo Lee, and Amy R. Ward

Published in: Dagstuhl Seminar Proceedings, Volume 9261, Models and Algorithms for Optimization in Logistics (2009)


Abstract
We consider the problem of designing a distribution network to facilitate the repeated movement of shipments from many origins to many destinations. A sufficient number of the origin-destination shipments require less than the capacity of a vehicle, so that consolidation of shipments is economical. We consider the case in which consolidation takes place at terminals, and we assume each shipment moves through exactly one terminal on its way from its origin to its destination. Then, a major design decision is to determine the best number of terminals. We develop a continuous approximation method to estimate transportation costs as a function of the number of terminals. We use the continuous approximation method to choose the number of terminals that minimizes the sum of terminal cost and transportation cost. Numerical results indicate that the design resulting from the continuous approximation method facilitates operations with lower cost than those resulting from a widely used integer programming based design.

Cite as

Anton J. Kleywegt, Jinpyo Lee, and Amy R. Ward. A Network Design Problem. In Models and Algorithms for Optimization in Logistics. Dagstuhl Seminar Proceedings, Volume 9261, pp. 1-56, Schloss Dagstuhl – Leibniz-Zentrum für Informatik (2009)


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@InProceedings{kleywegt_et_al:DagSemProc.09261.3,
  author =	{Kleywegt, Anton J. and Lee, Jinpyo and Ward, Amy R.},
  title =	{{A Network Design Problem}},
  booktitle =	{Models and Algorithms for Optimization in Logistics},
  pages =	{1--56},
  series =	{Dagstuhl Seminar Proceedings (DagSemProc)},
  ISSN =	{1862-4405},
  year =	{2009},
  volume =	{9261},
  editor =	{Cynthia Barnhart and Uwe Clausen and Ulrich Lauther and Rolf H. M\"{o}hring},
  publisher =	{Schloss Dagstuhl -- Leibniz-Zentrum f{\"u}r Informatik},
  address =	{Dagstuhl, Germany},
  URL =		{https://drops.dagstuhl.de/entities/document/10.4230/DagSemProc.09261.3},
  URN =		{urn:nbn:de:0030-drops-21768},
  doi =		{10.4230/DagSemProc.09261.3},
  annote =	{Keywords: Network design, continuous approximation}
}
Document
A Robust PTAS for the Parallel Machine Covering Problem

Authors: Martin Skutella and Jose Verschae

Published in: Dagstuhl Seminar Proceedings, Volume 9261, Models and Algorithms for Optimization in Logistics (2009)


Abstract
In general, combinatorial optimization problems are unstable: slight changes on the instance of a problem can render huge changes in the optimal solution. Thus, a natural question arises: Can we achieve stability if we only maintain approximate solutions?. In this talk I will first formalize these ideas, and then show some results on the parallel machine covering problem. In particular I will derive a robust PTAS, i.e., I will show how to construct a solution that is not only $(1-epsilon)$-approximate, but is also stable. That is, if the instance is changed by adding or removing a job, then we can construct a new near-optimal solution by only slightly modifying the previous one.

Cite as

Martin Skutella and Jose Verschae. A Robust PTAS for the Parallel Machine Covering Problem. In Models and Algorithms for Optimization in Logistics. Dagstuhl Seminar Proceedings, Volume 9261, pp. 1-3, Schloss Dagstuhl – Leibniz-Zentrum für Informatik (2009)


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@InProceedings{skutella_et_al:DagSemProc.09261.4,
  author =	{Skutella, Martin and Verschae, Jose},
  title =	{{A Robust PTAS for the Parallel Machine Covering Problem}},
  booktitle =	{Models and Algorithms for Optimization in Logistics},
  pages =	{1--3},
  series =	{Dagstuhl Seminar Proceedings (DagSemProc)},
  ISSN =	{1862-4405},
  year =	{2009},
  volume =	{9261},
  editor =	{Cynthia Barnhart and Uwe Clausen and Ulrich Lauther and Rolf H. M\"{o}hring},
  publisher =	{Schloss Dagstuhl -- Leibniz-Zentrum f{\"u}r Informatik},
  address =	{Dagstuhl, Germany},
  URL =		{https://drops.dagstuhl.de/entities/document/10.4230/DagSemProc.09261.4},
  URN =		{urn:nbn:de:0030-drops-21609},
  doi =		{10.4230/DagSemProc.09261.4},
  annote =	{Keywords: Stability, approximation schemes, online algorithms}
}
Document
Aspects and Views on Mathematical Optimization in Logistics in the Chemical Process Industry

Authors: Josef Kallrath

Published in: Dagstuhl Seminar Proceedings, Volume 9261, Models and Algorithms for Optimization in Logistics (2009)


Abstract
In large chemical companies, traffic logistics and supply chain logistics contain many decision problems which are suitable to be solved by mathematical optimization. The objectives are to exploit resources (traffic infrastructure such as roads and rail lines, production equipment) in a cost optimal way and to maximize profit. We present two cases: optimal sequences of rail cars in trains visiting various plants in a large company complex, and production and distribution planning. Finally, we discuss the importance of data structure and the consequences of differences between the "booking world" view of systems such as SAP and the "physical world" mapped into mathematical optimization models.

Cite as

Josef Kallrath. Aspects and Views on Mathematical Optimization in Logistics in the Chemical Process Industry. In Models and Algorithms for Optimization in Logistics. Dagstuhl Seminar Proceedings, Volume 9261, pp. 1-4, Schloss Dagstuhl – Leibniz-Zentrum für Informatik (2009)


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@InProceedings{kallrath:DagSemProc.09261.5,
  author =	{Kallrath, Josef},
  title =	{{Aspects and Views on Mathematical Optimization in Logistics in the Chemical Process Industry}},
  booktitle =	{Models and Algorithms for Optimization in Logistics},
  pages =	{1--4},
  series =	{Dagstuhl Seminar Proceedings (DagSemProc)},
  ISSN =	{1862-4405},
  year =	{2009},
  volume =	{9261},
  editor =	{Cynthia Barnhart and Uwe Clausen and Ulrich Lauther and Rolf H. M\"{o}hring},
  publisher =	{Schloss Dagstuhl -- Leibniz-Zentrum f{\"u}r Informatik},
  address =	{Dagstuhl, Germany},
  URL =		{https://drops.dagstuhl.de/entities/document/10.4230/DagSemProc.09261.5},
  URN =		{urn:nbn:de:0030-drops-21616},
  doi =		{10.4230/DagSemProc.09261.5},
  annote =	{Keywords: Logistics, traffic, supply chain, role of data, planning systems, data interfacing to SAP}
}
Document
Branch-and-Price Solving in G12

Authors: Jakob Puchinger, Peter Stuckey, Mark Wallace, and Sebastian Brand

Published in: Dagstuhl Seminar Proceedings, Volume 9261, Models and Algorithms for Optimization in Logistics (2009)


Abstract
The G12 project is developing a software environment for stating and solving combinatorial problems by mapping a high-level model of the problem to an efficient combination of solving methods. Model annotations are used to control this process. In this paper we explain the mapping to branch-and-price solving. G12 supports the selection of specialised subproblem solvers, the aggregation of identical subproblems, automatic disaggregation when required by search, and the use of specialised branching rules. We demonstrate the benefits of the G12 framework on three examples: a trucking problem, cutting stock, and two-dimensional bin packing.

Cite as

Jakob Puchinger, Peter Stuckey, Mark Wallace, and Sebastian Brand. Branch-and-Price Solving in G12. In Models and Algorithms for Optimization in Logistics. Dagstuhl Seminar Proceedings, Volume 9261, pp. 1-3, Schloss Dagstuhl – Leibniz-Zentrum für Informatik (2009)


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@InProceedings{puchinger_et_al:DagSemProc.09261.6,
  author =	{Puchinger, Jakob and Stuckey, Peter and Wallace, Mark and Brand, Sebastian},
  title =	{{Branch-and-Price Solving in G12}},
  booktitle =	{Models and Algorithms for Optimization in Logistics},
  pages =	{1--3},
  series =	{Dagstuhl Seminar Proceedings (DagSemProc)},
  ISSN =	{1862-4405},
  year =	{2009},
  volume =	{9261},
  editor =	{Cynthia Barnhart and Uwe Clausen and Ulrich Lauther and Rolf H. M\"{o}hring},
  publisher =	{Schloss Dagstuhl -- Leibniz-Zentrum f{\"u}r Informatik},
  address =	{Dagstuhl, Germany},
  URL =		{https://drops.dagstuhl.de/entities/document/10.4230/DagSemProc.09261.6},
  URN =		{urn:nbn:de:0030-drops-21641},
  doi =		{10.4230/DagSemProc.09261.6},
  annote =	{Keywords: Combinatorial optimization, branch-and-price, software}
}
Document
Comparing Different Approaches on the Door Assignment Problem in LTL-Terminals

Authors: Boris Naujoks and Annette Chmielewski

Published in: Dagstuhl Seminar Proceedings, Volume 9261, Models and Algorithms for Optimization in Logistics (2009)


Abstract
The work at hand yields two different ways to address the assignment of inbound and outbound doors in less-than-truckload terminals. The considered optimization methods stem from two different scientific fields, which makes the comparison of the techniques a very interesting topic. The first solution approach origins from the field of discrete mathematics. For this purpose, the logistical optimization task is modeled as a time-discrete multi-commodity flow problem with side constraints. Based on this model, a decomposition approach and a modified column generation approach are developed. The second considered optimization method is an evolutionary multi-objective optimization algorithm (EMOA). This approach is able to handle different optimization goals in parallel. Both algorithms are applied to ten test scenarios yielding different numbers of tours, doors, loading areas, and affected relations.

Cite as

Boris Naujoks and Annette Chmielewski. Comparing Different Approaches on the Door Assignment Problem in LTL-Terminals. In Models and Algorithms for Optimization in Logistics. Dagstuhl Seminar Proceedings, Volume 9261, pp. 1-9, Schloss Dagstuhl – Leibniz-Zentrum für Informatik (2009)


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@InProceedings{naujoks_et_al:DagSemProc.09261.7,
  author =	{Naujoks, Boris and Chmielewski, Annette},
  title =	{{Comparing Different Approaches on the Door Assignment Problem in LTL-Terminals}},
  booktitle =	{Models and Algorithms for Optimization in Logistics},
  pages =	{1--9},
  series =	{Dagstuhl Seminar Proceedings (DagSemProc)},
  ISSN =	{1862-4405},
  year =	{2009},
  volume =	{9261},
  editor =	{Cynthia Barnhart and Uwe Clausen and Ulrich Lauther and Rolf H. M\"{o}hring},
  publisher =	{Schloss Dagstuhl -- Leibniz-Zentrum f{\"u}r Informatik},
  address =	{Dagstuhl, Germany},
  URL =		{https://drops.dagstuhl.de/entities/document/10.4230/DagSemProc.09261.7},
  URN =		{urn:nbn:de:0030-drops-21870},
  doi =		{10.4230/DagSemProc.09261.7},
  annote =	{Keywords: Door Assignment Problem, Column Generation Approach, Multi-objective evolutionary algorithm approach}
}
Document
Formulations, Bounds and Heuristic Methods for a Two-Echelon Adaptive Location-Distribution Problem

Authors: Bernard Gendron, Paul-Virak Khuong, and Frédéric Semet

Published in: Dagstuhl Seminar Proceedings, Volume 9261, Models and Algorithms for Optimization in Logistics (2009)


Abstract
We consider a two-echelon location-distribution problem arising from an actual application in fast delivery service. This problem belongs to the class of adaptive logistics problems, as the locations of the facilities (typically, parking spaces) are revised on a daily basis according to demand variations. We present and compare two formulations for this problem: an arc-based model and a path-based model. Since these formulations cannot be solved in reasonable time for large-scale instances, we introduce a heuristic method based on a variable neighborhood search approach.

Cite as

Bernard Gendron, Paul-Virak Khuong, and Frédéric Semet. Formulations, Bounds and Heuristic Methods for a Two-Echelon Adaptive Location-Distribution Problem. In Models and Algorithms for Optimization in Logistics. Dagstuhl Seminar Proceedings, Volume 9261, pp. 1-3, Schloss Dagstuhl – Leibniz-Zentrum für Informatik (2009)


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@InProceedings{gendron_et_al:DagSemProc.09261.8,
  author =	{Gendron, Bernard and Khuong, Paul-Virak and Semet, Fr\'{e}d\'{e}ric},
  title =	{{Formulations, Bounds and Heuristic Methods for a Two-Echelon Adaptive Location-Distribution Problem}},
  booktitle =	{Models and Algorithms for Optimization in Logistics},
  pages =	{1--3},
  series =	{Dagstuhl Seminar Proceedings (DagSemProc)},
  ISSN =	{1862-4405},
  year =	{2009},
  volume =	{9261},
  editor =	{Cynthia Barnhart and Uwe Clausen and Ulrich Lauther and Rolf H. M\"{o}hring},
  publisher =	{Schloss Dagstuhl -- Leibniz-Zentrum f{\"u}r Informatik},
  address =	{Dagstuhl, Germany},
  URL =		{https://drops.dagstuhl.de/entities/document/10.4230/DagSemProc.09261.8},
  URN =		{urn:nbn:de:0030-drops-21892},
  doi =		{10.4230/DagSemProc.09261.8},
  annote =	{Keywords: Two-echelon location problem, formulations, relaxations, variable neighborhood search}
}
Document
Grammar-Based Integer Programing Models for Multi-Activity Shift Scheduling

Authors: Marie-Claude Cote, Bernard Gendron, and Louis-Martin Rousseau

Published in: Dagstuhl Seminar Proceedings, Volume 9261, Models and Algorithms for Optimization in Logistics (2009)


Abstract
We present a new implicit formulation for shift scheduling problems, using context-free grammars to model regulation in the composition of shifts. From the grammar, we generate an integer programming (IP) model allowing the same set of shifts as Dantzig’s set covering model. When solved by a state-of-the- art IP solver on problems allowing a small number of shifts, our model, the set covering formulation and a typical implicit model from the literature yield comparable solving times. Moreover, on instances where many shifts are allowed, our model is superior and can encode a wider variety of constraints. Among others, multi-activity cases, which cannot be modeled by existing implicit formulations, can easily be captured with grammars.

Cite as

Marie-Claude Cote, Bernard Gendron, and Louis-Martin Rousseau. Grammar-Based Integer Programing Models for Multi-Activity Shift Scheduling. In Models and Algorithms for Optimization in Logistics. Dagstuhl Seminar Proceedings, Volume 9261, pp. 1-2, Schloss Dagstuhl – Leibniz-Zentrum für Informatik (2009)


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@InProceedings{cote_et_al:DagSemProc.09261.9,
  author =	{Cote, Marie-Claude and Gendron, Bernard and Rousseau, Louis-Martin},
  title =	{{Grammar-Based Integer Programing Models for Multi-Activity Shift Scheduling}},
  booktitle =	{Models and Algorithms for Optimization in Logistics},
  pages =	{1--2},
  series =	{Dagstuhl Seminar Proceedings (DagSemProc)},
  ISSN =	{1862-4405},
  year =	{2009},
  volume =	{9261},
  editor =	{Cynthia Barnhart and Uwe Clausen and Ulrich Lauther and Rolf H. M\"{o}hring},
  publisher =	{Schloss Dagstuhl -- Leibniz-Zentrum f{\"u}r Informatik},
  address =	{Dagstuhl, Germany},
  URL =		{https://drops.dagstuhl.de/entities/document/10.4230/DagSemProc.09261.9},
  URN =		{urn:nbn:de:0030-drops-21775},
  doi =		{10.4230/DagSemProc.09261.9},
  annote =	{Keywords: Shift Scheduling, Implicit models, Integer Programming, Context-free grammars}
}
Document
Humanitarian Supply Chain Management - An Overview

Authors: Ozlem Ergun, Gonca Karakus, Pinar Keskinocak, Julie Swann, and Monica Villarreal

Published in: Dagstuhl Seminar Proceedings, Volume 9261, Models and Algorithms for Optimization in Logistics (2009)


Abstract
Disasters recently received the attention of the Operations Research community due to the great potential of improving disaster related operations through the use of analytical tools, and the impact on people that this implies. In this introductory article, we describe the main characteristics of disaster supply chains, and we highlight the particular issues that are faced when managing these supply chains. We illustrate how Operations Research tools can be used to make better decisions, taking debris management operations as an example, and discuss potential general research directions in this area.

Cite as

Ozlem Ergun, Gonca Karakus, Pinar Keskinocak, Julie Swann, and Monica Villarreal. Humanitarian Supply Chain Management - An Overview. In Models and Algorithms for Optimization in Logistics. Dagstuhl Seminar Proceedings, Volume 9261, pp. 1-5, Schloss Dagstuhl – Leibniz-Zentrum für Informatik (2009)


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@InProceedings{ergun_et_al:DagSemProc.09261.10,
  author =	{Ergun, Ozlem and Karakus, Gonca and Keskinocak, Pinar and Swann, Julie and Villarreal, Monica},
  title =	{{Humanitarian Supply Chain Management - An Overview}},
  booktitle =	{Models and Algorithms for Optimization in Logistics},
  pages =	{1--5},
  series =	{Dagstuhl Seminar Proceedings (DagSemProc)},
  ISSN =	{1862-4405},
  year =	{2009},
  volume =	{9261},
  editor =	{Cynthia Barnhart and Uwe Clausen and Ulrich Lauther and Rolf H. M\"{o}hring},
  publisher =	{Schloss Dagstuhl -- Leibniz-Zentrum f{\"u}r Informatik},
  address =	{Dagstuhl, Germany},
  URL =		{https://drops.dagstuhl.de/entities/document/10.4230/DagSemProc.09261.10},
  URN =		{urn:nbn:de:0030-drops-21819},
  doi =		{10.4230/DagSemProc.09261.10},
  annote =	{Keywords: Humanitarian logistics}
}
Document
Improving the perfomance of elevator systems using exact reoptimization algorithms

Authors: Benjamin Hiller, Torsten Klug, and Andreas Tuchscherer

Published in: Dagstuhl Seminar Proceedings, Volume 9261, Models and Algorithms for Optimization in Logistics (2009)


Abstract
The task of an elevator control is to schedule the elevators of a group such that small average and maximal waiting and travel times for the passengers are obtained. We present a novel exact reoptimization algorithm for this problem. A reoptimization algorithm computes a new optimal schedule for the elevator group each time a new passenger arrives. Our algorithm uses column generation techniques and is, to the best of our knowledge, the first exact reoptimization algorithm for a group of elevators. We use our algorithm to compare the potential performance that can be achieved for conventional (ie up/down buttons) and two variants of destination call systems, where a passenger enters his destination floor when calling an elevator. This research is part of an ongoing project with our industry partner Kollmorgen Steuerungstechnik.

Cite as

Benjamin Hiller, Torsten Klug, and Andreas Tuchscherer. Improving the perfomance of elevator systems using exact reoptimization algorithms. In Models and Algorithms for Optimization in Logistics. Dagstuhl Seminar Proceedings, Volume 9261, pp. 1-4, Schloss Dagstuhl – Leibniz-Zentrum für Informatik (2009)


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@InProceedings{hiller_et_al:DagSemProc.09261.11,
  author =	{Hiller, Benjamin and Torsten Klug and Andreas Tuchscherer},
  title =	{{Improving the perfomance of elevator systems using exact reoptimization algorithms}},
  booktitle =	{Models and Algorithms for Optimization in Logistics},
  pages =	{1--4},
  series =	{Dagstuhl Seminar Proceedings (DagSemProc)},
  ISSN =	{1862-4405},
  year =	{2009},
  volume =	{9261},
  editor =	{Cynthia Barnhart and Uwe Clausen and Ulrich Lauther and Rolf H. M\"{o}hring},
  publisher =	{Schloss Dagstuhl -- Leibniz-Zentrum f{\"u}r Informatik},
  address =	{Dagstuhl, Germany},
  URL =		{https://drops.dagstuhl.de/entities/document/10.4230/DagSemProc.09261.11},
  URN =		{urn:nbn:de:0030-drops-21799},
  doi =		{10.4230/DagSemProc.09261.11},
  annote =	{Keywords: Elevator control, reoptimization, online optimization}
}
Document
Increasing Stability of Crew Schedules in Airlines

Authors: Leena Suhl, Viktor Dück, and Natalia Kliewer

Published in: Dagstuhl Seminar Proceedings, Volume 9261, Models and Algorithms for Optimization in Logistics (2009)


Abstract
In airline traffic disruptions occur frequently and cannot be totally avoided. They may lead to infeasible aircraft and crew schedules during the day of operations, due to absence of resources or violation of crew rules. The process of finding new schedules in such cases is called recovery or disruption management. The short-term recovery actions usually imply additional costs meaning that the total operational costs of a crew schedule can be significantly higher than the original planned costs. It is generally desirable to construct the schedule already in the planning phase in such a way that not just the planned costs, but the total operational costs are minimized. The goal is thus to construct schedules which remain feasible or can be recovered without high costs in cases of disturbances. This approach is generally called robust scheduling.

Cite as

Leena Suhl, Viktor Dück, and Natalia Kliewer. Increasing Stability of Crew Schedules in Airlines. In Models and Algorithms for Optimization in Logistics. Dagstuhl Seminar Proceedings, Volume 9261, pp. 1-3, Schloss Dagstuhl – Leibniz-Zentrum für Informatik (2009)


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@InProceedings{suhl_et_al:DagSemProc.09261.12,
  author =	{Suhl, Leena and D\"{u}ck, Viktor and Kliewer, Natalia},
  title =	{{Increasing Stability of Crew Schedules in Airlines}},
  booktitle =	{Models and Algorithms for Optimization in Logistics},
  pages =	{1--3},
  series =	{Dagstuhl Seminar Proceedings (DagSemProc)},
  ISSN =	{1862-4405},
  year =	{2009},
  volume =	{9261},
  editor =	{Cynthia Barnhart and Uwe Clausen and Ulrich Lauther and Rolf H. M\"{o}hring},
  publisher =	{Schloss Dagstuhl -- Leibniz-Zentrum f{\"u}r Informatik},
  address =	{Dagstuhl, Germany},
  URL =		{https://drops.dagstuhl.de/entities/document/10.4230/DagSemProc.09261.12},
  URN =		{urn:nbn:de:0030-drops-21786},
  doi =		{10.4230/DagSemProc.09261.12},
  annote =	{Keywords: Robust planning, crew scheduling, airlines}
}
Document
Integrated Vehicle Routing and Crew Scheduling in Waste Management (Part I)

Authors: Ronny Hansmann and Uwe Zimmermann

Published in: Dagstuhl Seminar Proceedings, Volume 9261, Models and Algorithms for Optimization in Logistics (2009)


Abstract
Planning Waste Management involves the two major resources collection-vehicles and crews. The overall goal of our project with two waste management companies is an integrative approach for planning the routes and the crews of the vehicles. In the first phase of our three-phase approach we generate daily crew tasks which contain routes operated by a single crew at a particular day within a given disposal horizon considering various practical requirements. The goal is to minimize the number of crews/vehicles required for the entire disposal process. Given the minimal number of crews, in phase 2 we re-optimize the daily crew tasks to increase the robustness of the routes. In the third phase we assign employees to the generated daily crew tasks for all working days over the year such that the constraints concerning crew scheduling are satisfied and the benefits for the employees and the company are maximal. For all phases we present solution methods yielding first promising results for a real-world data set.

Cite as

Ronny Hansmann and Uwe Zimmermann. Integrated Vehicle Routing and Crew Scheduling in Waste Management (Part I). In Models and Algorithms for Optimization in Logistics. Dagstuhl Seminar Proceedings, Volume 9261, pp. 1-8, Schloss Dagstuhl – Leibniz-Zentrum für Informatik (2009)


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@InProceedings{hansmann_et_al:DagSemProc.09261.13,
  author =	{Hansmann, Ronny and Zimmermann, Uwe},
  title =	{{Integrated Vehicle Routing and Crew Scheduling in Waste Management (Part I)}},
  booktitle =	{Models and Algorithms for Optimization in Logistics},
  pages =	{1--8},
  series =	{Dagstuhl Seminar Proceedings (DagSemProc)},
  ISSN =	{1862-4405},
  year =	{2009},
  volume =	{9261},
  editor =	{Cynthia Barnhart and Uwe Clausen and Ulrich Lauther and Rolf H. M\"{o}hring},
  publisher =	{Schloss Dagstuhl -- Leibniz-Zentrum f{\"u}r Informatik},
  address =	{Dagstuhl, Germany},
  URL =		{https://drops.dagstuhl.de/entities/document/10.4230/DagSemProc.09261.13},
  URN =		{urn:nbn:de:0030-drops-21859},
  doi =		{10.4230/DagSemProc.09261.13},
  annote =	{Keywords: Vehicle Routing, Crew Scheduling, Waste Management}
}
Document
Integrated Vehicle Routing and Crew Scheduling in Waste Management (Part II)

Authors: Jens Baudach, Annette Chmielewski, and Uwe Clausen

Published in: Dagstuhl Seminar Proceedings, Volume 9261, Models and Algorithms for Optimization in Logistics (2009)


Abstract
Planning Waste Management involves the two major resources collection-vehicles and crews. The overall goal of our project with two waste management companies is an integrative approach for planning the routes and the crews of the vehicles. In the first phase of our three-phase approach we generate daily crew tasks which contain routes operated by a single crew at a particular day within a given disposal horizon considering various practical requirements. The goal is to minimize the number of crews/vehicles required for the entire disposal process. Given the minimal number of crews, in phase 2 we re-optimize the daily crew tasks to increase the robustness of the routes. In the third phase we assign employees to the generated daily crew tasks for all working days over the year such that the constraints concerning crew scheduling are satisfied and the benefits for the employees and the company are maximal. For all phases we present solution methods yielding first promising results for a real-world data set.

Cite as

Jens Baudach, Annette Chmielewski, and Uwe Clausen. Integrated Vehicle Routing and Crew Scheduling in Waste Management (Part II). In Models and Algorithms for Optimization in Logistics. Dagstuhl Seminar Proceedings, Volume 9261, pp. 1-5, Schloss Dagstuhl – Leibniz-Zentrum für Informatik (2009)


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@InProceedings{baudach_et_al:DagSemProc.09261.14,
  author =	{Baudach, Jens and Chmielewski, Annette and Clausen, Uwe},
  title =	{{Integrated Vehicle Routing and Crew Scheduling in Waste Management (Part II)}},
  booktitle =	{Models and Algorithms for Optimization in Logistics},
  pages =	{1--5},
  series =	{Dagstuhl Seminar Proceedings (DagSemProc)},
  ISSN =	{1862-4405},
  year =	{2009},
  volume =	{9261},
  editor =	{Cynthia Barnhart and Uwe Clausen and Ulrich Lauther and Rolf H. M\"{o}hring},
  publisher =	{Schloss Dagstuhl -- Leibniz-Zentrum f{\"u}r Informatik},
  address =	{Dagstuhl, Germany},
  URL =		{https://drops.dagstuhl.de/entities/document/10.4230/DagSemProc.09261.14},
  URN =		{urn:nbn:de:0030-drops-21836},
  doi =		{10.4230/DagSemProc.09261.14},
  annote =	{Keywords: Crew Scheduling, Waste Management, Integer Programming, Column Generation, Lagrangean Relaxation}
}
Document
Line Planning and Connectivity

Authors: Ralf Borndörfer, Marika Neumann, and Marc E. Pfetsch

Published in: Dagstuhl Seminar Proceedings, Volume 9261, Models and Algorithms for Optimization in Logistics (2009)


Abstract
The line planning problem in public transport deals with the construction of a system of lines that is both attractive for the passengers and of low costs for the operator. In general, the computed line system should be connected, i.e., for each two stations there have to be a path that is covered by the lines. This subproblem is a generalization of the well-known Steiner tree problem; we call it the Steiner connectivity Problem. We discuss complexity of this problem, generalize the so-called Steiner partition inequalities and give a transformation to the directed Steiner tree problem. We show that directed models provide tight formulations for the Steiner connectivity problem, similar as for the Steiner tree problem.

Cite as

Ralf Borndörfer, Marika Neumann, and Marc E. Pfetsch. Line Planning and Connectivity. In Models and Algorithms for Optimization in Logistics. Dagstuhl Seminar Proceedings, Volume 9261, pp. 1-3, Schloss Dagstuhl – Leibniz-Zentrum für Informatik (2009)


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@InProceedings{borndorfer_et_al:DagSemProc.09261.15,
  author =	{Bornd\"{o}rfer, Ralf and Neumann, Marika and Pfetsch, Marc E.},
  title =	{{Line Planning and Connectivity}},
  booktitle =	{Models and Algorithms for Optimization in Logistics},
  pages =	{1--3},
  series =	{Dagstuhl Seminar Proceedings (DagSemProc)},
  ISSN =	{1862-4405},
  year =	{2009},
  volume =	{9261},
  editor =	{Cynthia Barnhart and Uwe Clausen and Ulrich Lauther and Rolf H. M\"{o}hring},
  publisher =	{Schloss Dagstuhl -- Leibniz-Zentrum f{\"u}r Informatik},
  address =	{Dagstuhl, Germany},
  URL =		{https://drops.dagstuhl.de/entities/document/10.4230/DagSemProc.09261.15},
  URN =		{urn:nbn:de:0030-drops-21661},
  doi =		{10.4230/DagSemProc.09261.15},
  annote =	{Keywords: Steiner tree, generalization, paths}
}
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