1,425 Hits in 5.2 sec

Recoverable Robust Timetable Information

Marc Goerigk, Sacha Heße, Matthias Müller-Hannemann, Marie Schmidt, Anita Schöbel, Marc Herbstritt
2013 Algorithmic Approaches for Transportation Modeling, Optimization, and Systems  
Timetable information is the process of determining a suitable travel route for a passenger.  ...  In this work we propose a recoverable robust approach to timetable information; i.e., we aim at finding travel routes that can easily be updated when delays occur during the journey.  ...  The proposed concept and algorithm was experimentally evaluated on timetable information instances covering the whole German train network (schedule of 2013).  ... 
doi:10.4230/oasics.atmos.2013.1 dblp:conf/atmos/GoerigkHMSS13 fatcat:wrwyv2vfcfgppc73akoh6oniju

Multimodal Dynamic Journey-Planning

Kalliopi Giannakopoulou, Andreas Paraskevopoulos, Christos Zaroliagis
2019 Algorithms  
An experimental study on real-world metropolitan networks demonstrates that the query and update algorithms of Multimodal DTM compare favorably with other state-of-the-art approaches when public transport  ...  Multimodal DTM demonstrates a very fast query algorithm that meets the requirement for real-time response to best journey queries, and an ultra-fast update algorithm for updating the timetable information  ...  The last author is indebted to Tobias Zündorf for various interesting discussions. Conflicts of Interest: The authors declare no conflict of interest.  ... 
doi:10.3390/a12100213 fatcat:gsth2m5kk5ddfp4ycnm3tjopxi

Efficient models for timetable information in public transportation systems

Evangelia Pyrga, Frank Schulz, Dorothea Wagner, Christos Zaroliagis
2008 ACM Journal of Experimental Algorithmics  
We consider two approaches that model timetable information in public transportation systems as shortest-path problems in weighted graphs.  ...  Thus far, there are only theoretical arguments in favor of the time-dependent approach. In this paper, we provide the first extensive experimental comparison of the two approaches.  ...  approach for timetable information problems.  ... 
doi:10.1145/1227161.1227166 fatcat:v5fvudkb3nbibkc7ysgcbpdhlq

The Price of Robustness in Timetable Information

Marc Goerigk, Martin Knoth, Matthias Müller-Hannemann, Marie Schmidt, Anita Schöbel, Marc Herbstritt
2011 Algorithmic Approaches for Transportation Modeling, Optimization, and Systems  
In timetable information in public transport the goal is to search for a good passenger's path between an origin and a destination.  ...  We also transfer the notion of light robustness, originally introduced for timetabling, to timetable information.  ...  Compared to the approach of strictly robust timetable information, light robust paths are not necessarily maintained under disruptions.  ... 
doi:10.4230/oasics.atmos.2011.76 dblp:conf/atmos/GoerigkKMSS11 fatcat:fqvjdqfxv5gyfbrh4o7shcg7wi

Engineering Time-Expanded Graphs for Faster Timetable Information [chapter]

Daniel Delling, Thomas Pajor, Dorothea Wagner
2009 Lecture Notes in Computer Science  
We present an extension of the well-known time-expanded approach for timetable information.  ...  Moreover, we show that our extensions harmonize well with speed-up techniques whose adaption to timetable networks is more challenging than one might expect.  ...  The Condensed Model is the easiest approach for modeling timetable information.  ... 
doi:10.1007/978-3-642-05465-5_7 fatcat:u6vzy4yggzfthphx6zrsznlyx4

Engineering Algorithms for Large Network Applications [chapter]

Christos Zaroliagis
2008 Encyclopedia of Algorithms  
Cross References Implementation Challenge for Shortest Paths Shortest Paths Approaches for Timetable Information Recommended Reading  ...  Although the straightforward approach of pre-computing and storing shortest paths for all pairs of vertices would enabling the optimal answering of shortest path queries, the quadratic space requirements  ... 
doi:10.1007/978-0-387-30162-4_125 fatcat:n6q7opnewzgoxcns73ta37ipqq

Disaggregation in Bundle Methods: Application to the Train Timetabling Problem [article]

Abderrahman Ait Ali, Per Olov Lindberg, Jan-Eric Nilsson, Jonas Eliasson, Martin Aronsson
2017 arXiv   pre-print
Bundle methods are often used to solve dual problems that arise from Lagrangian relaxations of large scale optimization problems. An example of such problems is the train timetabling problem.  ...  The numerical results show that the new disaggregate approach generally yields faster convergence than the standard aggregate approach.  ...  Figure 7 -The final pricing and timetable for the two approaches from test case S1 In each iteration, the shortest path algorithm is called to find the best paths for a given pricing.  ... 
arXiv:1702.08879v1 fatcat:skiuapiqorcujagrtuheie3sru

Is Timetabling Routing Always Reliable for Public Transport?

Donatella Firmani, Giuseppe F. Italiano, Luigi Laura, Federico Santaroni, Marc Herbstritt
2013 Algorithmic Approaches for Transportation Modeling, Optimization, and Systems  
Current route planning algorithms for public transport networks are mostly based on timetable information only, i.e., they compute shortest routes under the assumption that all transit vehicles (e.g.,  ...  In our experiments, the movement of transit vehicles was only mildly correlated to the timetable, giving strong evidence that in such a case timetabled routing may fail to deliver optimal or even high-quality  ...  Acknowledgements We wish to thank the transit agency of Rome, Roma Servizi per la Mobilità, and in particular Luca Allulli, Carlo Gentile, Damiano Morosi, and Fabio Schiavo, for their kind assistance with  ... 
doi:10.4230/oasics.atmos.2013.15 dblp:conf/atmos/FirmaniILS13 fatcat:7zzoxwy6ynca3oeihvagjfizqm

Shortest Path with Alternatives for Uniform Arrival Times: Algorithms and Experiments

Tim Nonner, Marco Laumanns, Marc Herbstritt
2014 Algorithmic Approaches for Transportation Modeling, Optimization, and Systems  
The Shortest Path with Alternatives (SPA) policy differs from classical shortest path routing in the following way: instead of providing an exact list of means of transportation to follow, this policy  ...  of user experience, compared to similar greedy approaches.  ...  We are interested in comparing the following policies: (P1) a classical single shortest path using an exact timetable, (P2) a SPA policy using a post-processed timetable with frequency information, but  ... 
doi:10.4230/oasics.atmos.2014.15 dblp:conf/atmos/NonnerL14 fatcat:2zgrp5grajbbvb7h4p6adaboyi

Towards Realistic Modeling of Time-Table Information through the Time-Dependent Approach

Evangelia Pyrga, Frank Schulz, Dorothea Wagner, Christos Zaroliagis
2004 Electronical Notes in Theoretical Computer Science  
We consider optimal itinerary problems in time-table information systems supporting a vast number of on-line queries.  ...  could not be modeled by the original version of the time-dependent approach.  ...  The common characteristic of both approaches is that a query is answered by applying some shortest path algorithm to a suitably constructed digraph.  ... 
doi:10.1016/j.entcs.2003.12.024 fatcat:nkkeivfsnnckdc72zjhubloliy

Multimodal Dynamic Journey Planning [article]

Kalliopi Giannakopoulou, Andreas Paraskevopoulos, Christos Zaroliagis
2018 arXiv   pre-print
Multimodal DTM exhibits a very fast query algorithm, meeting the request for real-time response to best journey queries and an extremely fast update algorithm for updating the timetable information in  ...  Multimodal DTM constitutes an extension of the dynamic timetable model (DTM), developed originally for unimodal journey planning.  ...  The last author is indebted to Tobias Zündorf for various interesting discussions.  ... 
arXiv:1804.05644v1 fatcat:saqjcttucjcnvgvilqm3idohsq

Engineering graph-based models for dynamic timetable information systems

Alessio Cionini, Gianlorenzo D'Angelo, Mattia D'Emidio, Daniele Frigioni, Kalliopi Giannakopoulou, Andreas Paraskevopoulos, Christos Zaroliagis
2017 Journal of Discrete Algorithms  
The array-based models have been shown to be very effective in terms of query time, while the graph-based models usually answer queries by computing shortest paths, and hence they are suitable to be used  ...  tailored for handling dynamic updates; (iii) we assess the effectiveness of the proposed models and algorithms by an experimental study, which shows that both models require negligible update time and  ...  for shortest path developed during the last years.  ... 
doi:10.1016/j.jda.2017.09.001 fatcat:hajukvpz5nfrllpv75dpzs4ro4

Combining speed-up techniques for shortest-path computations

Martin Holzer, Frank Schulz, Dorothea Wagner, Thomas Willhalm
2005 ACM Journal of Experimental Algorithmics  
We consider all possible combinations of four known techniques, namely goaldirected search, bidirectional search, multi-level approach, and shortest-path containers, and show how these can be implemented  ...  The focus of our work is combination of speed-up techniques for Dijkstra's algorithm.  ...  the shortest-path problem with better running time (worst-case or average-case; see [Cherkassky et al., 1996] for an experimental comparison, [Zwick, 2001] for a survey, and [Goldberg, 2001b , Meyer  ... 
doi:10.1145/1064546.1180616 fatcat:ar6ozx6gzjaqlno4zxvakndtz4

Combining Speedup Techniques based on Landmarks and Containers with parallelised preprocessing in Random and Planar Graphs

R Kalpana, P Thambidurai
2011 International Journal of Computer Science & Information Technology (IJCSIT)  
The experimental results were compared and analysed for determining better performance improvements in random graphs and planar graphs.  ...  Space requirements for the pre-processing also have a major influence on the running time of the algorithm.  ...  Timetable information queries could be improved by a factor of 11 [5] . • Shortest-path containers: These containers [6] provide a necessary condition for each edge, whether or not it has to be respected  ... 
doi:10.5121/ijcsit.2011.3111 fatcat:ef23a45cxjc3rdrdkqqlaz6cgi

A multimodal transport network model and efficient algorithms for building advanced traveler information systems

Omar Dib, Marie-Ange Manier, Laurent Moalic, Alexandre Caminada
2017 Transportation Research Procedia  
Acknowledgments This research work has been carried out in the framework of the Technological Research Institute SystemX, and therefore granted with public funds within the scope of the French Program  ...  Although scheduled based transportation modes have a time dependency arised from timetable information, the proposed modeling approach allows solving the emerging problem as a variant of the shortest path  ...  Data comprise geographical information, as well as, timetable information for four transport modes, which are Bus, Metro, Railway, and Tram.  ... 
doi:10.1016/j.trpro.2017.03.020 fatcat:ugblatdljjhhlnd6nomcndqi3e
« Previous Showing results 1 — 15 out of 1,425 results