Library

X
feed icon rss

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
Filter
  • 2015-2019
  • 2010-2014  (13)
  • 2000-2004  (5)
  • 2013  (13)
  • 2000  (5)
Source
Material
Years
  • 2015-2019
  • 2010-2014  (13)
  • 2000-2004  (5)
Year
Keywords
Language
  • 1
    Electronic Resource
    Electronic Resource
    Set packing relaxations of some integer programs (2000)
    Springer
    Mathematical programming 88 (2000), S. 425-450 
    Details
    ISSN: 1436-4646
    Keywords: Key words: set packing – polyhedral combinatorics – cutting planes – integer programming ; Mathematics Subject Classification (2000): 90C10
    Source: Springer Online Journal Archives 1860-2000
    Topics: Computer Science , Mathematics
    Notes: Abstract. This paper is about set packing relaxations of combinatorial optimization problems associated with acyclic digraphs and linear orderings, cuts and multicuts, and set packings themselves. Families of inequalities that are valid for such a relaxation as well as the associated separation routines carry over to the problems under investigation.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/PL00011381
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 2
    facet.materialart.
    Unknown
    The Freight Train Routing Problem (2013)
    Details
    Publication Date: 2020-08-05
    Description: We consider the following freight train routing problem (FTRP). Given is a transportation network with fixed routes for passenger trains and a set of freight trains (requests), each defined by an origin and destination station pair. The objective is to calculate a feasible route for each freight train such that a sum of all expected delays and all running times is minimal. Previous research concentrated on microscopic train routings for junctions or inside major stations. Only recently approaches were developed to tackle larger corridors or even networks. We investigate the routing problem from a strategic perspective, calculating the routes in a macroscopic transportation network of Deutsche Bahn AG. Here macroscopic refers to an aggregation of complex real-world structures are into fewer network elements. Moreover, the departure and arrival times of freight trains are approximated. The problem has a strategic character since it asks only for a coarse routing through the network without the precise timings. We give a mixed-integer nonlinear programming~(MINLP) formulation for FTRP, which is a multi-commodity flow model on a time-expanded graph with additional routing constraints. The model's nonlinearities are due to an algebraic approximation of the delays of the trains on the arcs of the network by capacity restraint functions. The MINLP is reduced to a mixed-integer linear model~(MILP) by piecewise linear approximation. The latter is solved by a state of the art MILP solver for various real-world test instances.
    Language: English
    Type: reportzib , doc-type:preprint
    Format: application/pdf
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    OPUS
  • 3
    facet.materialart.
    Unknown
    Optimierung im Nahverkehr (2000)
    Details
    Publication Date: 2020-08-05
    Language: English
    Type: other , doc-type:Other
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    OPUS
  • 4
    facet.materialart.
    Unknown
    Dienstplanoptimierung im ÖPNV (2000)
    Details
    Publication Date: 2020-08-05
    Language: English
    Type: other , doc-type:Other
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    OPUS
  • 5
    facet.materialart.
    Unknown
    Set Packing Relaxations of Some Integer Programs (2000)
    Details
    Publication Date: 2020-08-05
    Language: English
    Type: article , doc-type:article
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    OPUS
  • 6
    facet.materialart.
    Unknown
    Der schnellste Weg zum Ziel (2000)
    Details
    Publication Date: 2020-03-09
    Language: English
    Type: incollection , doc-type:Other
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    OPUS
  • 7
    facet.materialart.
    Unknown
    A Configuration Model for the Line Planning Problem (2013)
    Details
    Publication Date: 2020-08-05
    Description: We propose a novel extended formulation for the line planning problem in public transport. It is based on a new concept of frequency configurations that account for all possible options to provide a required transportation capacity on an infrastructure edge. We show that this model yields a strong LP relaxation. It implies, in particular, general classes of facet defining inequalities for the standard model.
    Language: English
    Type: reportzib , doc-type:preprint
    Format: application/pdf
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    OPUS
  • 8
    facet.materialart.
    Unknown
    HUHFA: A Framework for Facet Classification (2013)
    Details
    Publication Date: 2020-08-05
    Description: Usually complete linear descriptions of polytopes consist of an enormous number of facet-defining inequalities already for very small problem sizes. In this paper, we describe a method for dividing the inequalities into equivalence classes without resorting to a normal form. Within each class, facets are related by certain symmetries and it is sufficient to list one representative of each class to give a complete picture of the structural properties of a polytope. We propose an algorithm for the classification and illustrate its efficiency on a broad range of combinatorial optimization problems including the Traveling Salesman and the Linear Ordering Problem.
    Language: English
    Type: reportzib , doc-type:preprint
    Format: application/pdf
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    OPUS
  • 9
    facet.materialart.
    Unknown
    A Primal-Dual Approximation Algorithm for the Steiner Connectivity Problem (2013)
    Details
    Publication Date: 2020-08-05
    Description: We extend the primal-dual approximation technique of Goemans and Williamson to the Steiner connectivity problem, a kind of Steiner tree problem in hypergraphs. This yields a (k+1)-approximation algorithm for the case that k is the minimum of the maximal number of nodes in a hyperedge minus 1 and the maximal number of terminal nodes in a hyperedge. These results require the proof of a degree property for terminal nodes in hypergraphs which generalizes the well-known graph property that the average degree of terminal nodes in Steiner trees is at most 2.
    Language: English
    Type: reportzib , doc-type:preprint
    Format: application/pdf
    Format: application/pdf
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    OPUS
  • 10
    facet.materialart.
    Unknown
    How Many Steiner Terminals Can You Connect in 20 Years? (2013)
    Details
    Publication Date: 2020-08-05
    Description: Steiner trees are constructed to connect a set of terminal nodes in a graph. This basic version of the Steiner tree problem is idealized, but it can effectively guide the search for successful approaches to many relevant variants, from both a theoretical and a computational point of view. This article illustrates the theoretical and algorithmic progress on Steiner tree type problems on two examples, the Steiner connectivity and the Steiner tree packing problem.
    Language: English
    Type: reportzib , doc-type:preprint
    Format: application/pdf
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    OPUS
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...