Publications

Refereed Journal Articles

  1. [PDF] [DOI] Luis Gouveia, Markus Leitner, and Mario Ruthmair. Extended Formulations and Branch-and-Cut Algorithms for the Black-and-White Traveling Salesman Problem. European Journal of Operational Research, 262(3):908-928, 2017.
    [Bibtex]
    @Article{Gouveia2017,
    Title = {Extended Formulations and Branch-and-Cut Algorithms for the Black-and-White Traveling Salesman Problem},
    Author = {Gouveia, Luis and Leitner, Markus and Ruthmair, Mario},
    Journal = {European Journal of Operational Research},
    Year = {2017},
    Number = {3},
    Pages = {908--928},
    Volume = {262},
    Doi = {10.1016/j.ejor.2017.04.061},
    File = {:pdfs-own/Gouveia2017.pdf:PDF},
    Timestamp = {2017-06-163}
    }
  2. [PDF] [DOI] Luis Gouveia, Pierre Pesneau, Mario Ruthmair, and Daniel Santos. Combining and Projecting Flow Models for the (Precedence Constrained) Asymmetric Traveling Salesman Problem. Networks, 2017. to appear
    [Bibtex]
    @Article{Gouveia2017a,
    Title = {Combining and Projecting Flow Models for the (Precedence Constrained) Asymmetric Traveling Salesman Problem},
    Author = {Gouveia, Luis and Pesneau, Pierre and Ruthmair, Mario and Santos, Daniel},
    Journal = {Networks},
    Year = {2017},
    Note = {to appear},
    Doi = {10.1002/net.21765},
    File = {:pdfs-own/Gouveia2017a.pdf:PDF},
    Timestamp = {2017-08-235}
    }
  3. [PDF] [DOI] Piotr Matl, Pamela C. Nolz, Ulrike Ritzinger, Mario Ruthmair, and Fabien Tricoire. Bi-objective orienteering for personal activity scheduling. Computers & Operations Research, 82:69-82, 2017.
    [Bibtex]
    @Article{Matl2017,
    Title = {Bi-objective orienteering for personal activity scheduling},
    Author = {Piotr Matl and Pamela C. Nolz and Ulrike Ritzinger and Mario Ruthmair and Fabien Tricoire},
    Journal = {Computers \& Operations Research },
    Year = {2017},
    Pages = {69--82},
    Volume = {82},
    Doi = {10.1016/j.cor.2017.01.009},
    File = {:pdfs-own/Matl2017.pdf:PDF},
    ISSN = {0305-0548},
    Timestamp = {2017-01-31}
    }
  4. [PDF] [DOI] Johannes Asamer, Anita Graser, Bernhard Heilmann, and Mario Ruthmair. Sensitivity Analysis for Energy Demand Estimation of Electric Vehicles. Transportation Research Part D: Transport and Environment, 46:182-199, 2016.
    [Bibtex]
    @Article{Asamer2016a,
    Title = {Sensitivity Analysis for Energy Demand Estimation of Electric Vehicles},
    Author = {Johannes Asamer and Anita Graser and Bernhard Heilmann and Mario Ruthmair},
    Journal = {Transportation Research Part D: Transport and Environment},
    Year = {2016},
    Pages = {182--199},
    Volume = {46},
    Doi = {10.1016/j.trd.2016.03.017},
    File = {:pdfs-own/Asamer2016a.pdf:PDF},
    Timestamp = {2016-07-204}
    }
  5. [PDF] [DOI] Johannes Asamer, Martin Reinthaler, Mario Ruthmair, Markus Straub, and Jakob Puchinger. Optimizing Charging Station Locations for Urban Taxi Providers. Transportation Research Part A: Policy and Practice, 85:233-246, 2016.
    [Bibtex]
    @Article{Asamer2016,
    Title = {Optimizing Charging Station Locations for Urban Taxi Providers},
    Author = {Johannes Asamer and Martin Reinthaler and Mario Ruthmair and Markus Straub and Jakob Puchinger},
    Journal = {Transportation Research Part A: Policy and Practice},
    Year = {2016},
    Pages = {233--246},
    Volume = {85},
    Doi = {10.1016/j.tra.2016.01.014},
    File = {:pdfs-own/Asamer2016.pdf:PDF},
    Timestamp = {2016-02-43}
    }
  6. [PDF] [DOI] Liujiang Kang, Xiaoning Zhu, Jianjun Wu, Jakob Puchinger, Mario Ruthmair, and Bin Hu. Modeling and solving the first train timetabling problem with minimal missed trains in subway networks. Transportation Research Part B: Methodological, 93, Part A:17-36, 2016.
    [Bibtex]
    @Article{Kang2016,
    Title = {Modeling and solving the first train timetabling problem with minimal missed trains in subway networks},
    Author = {Liujiang Kang and Xiaoning Zhu and Jianjun Wu and Jakob Puchinger and Mario Ruthmair and Bin Hu},
    Journal = {Transportation Research Part B: Methodological},
    Year = {2016},
    Pages = {17--36},
    Volume = {93, Part A},
    Doi = {10.1016/j.trb.2016.07.006},
    File = {:pdfs-own/Kang2016.pdf:PDF},
    ISSN = {0191-2615},
    Timestamp = {2016-07-204}
    }
  7. [PDF] [DOI] Luis Gouveia and Mario Ruthmair. Load-Dependent and Precedence-Based Models for Pickup and Delivery Problems. Computers & Operations Research, 63:56-71, 2015.
    [Bibtex]
    @Article{Gouveia2015,
    Title = {Load-Dependent and Precedence-Based Models for Pickup and Delivery Problems},
    Author = {Gouveia, Luis and Ruthmair, Mario},
    Journal = {Computers \& Operations Research},
    Year = {2015},
    Pages = {56--71},
    Volume = {63},
    Doi = {10.1016/j.cor.2015.04.008},
    File = {:pdfs-own/Gouveia2015.pdf:PDF},
    Timestamp = {2015.05.23}
    }
  8. [PDF] [DOI] Luis Gouveia, Pedro Moura, Mario Ruthmair, and Amaro Sousa. Spanning Trees with Variable Degree Bounds. European Journal of Operational Research, 239(3):830-841, 2014.
    [Bibtex]
    @Article{Gouveia2014,
    Title = {Spanning Trees with Variable Degree Bounds},
    Author = {Gouveia, Luis and Moura, Pedro and Ruthmair, Mario and Sousa, Amaro},
    Journal = {European Journal of Operational Research},
    Year = {2014},
    Number = {3},
    Pages = {830--841},
    Volume = {239},
    Doi = {10.1016/j.ejor.2014.05.034},
    File = {:pdfs-own/Gouveia2014.pdf:PDF},
    Timestamp = {2015.05.23}
    }
  9. [PDF] [DOI] Markus Leitner, Mario Ruthmair, and Günther R. Raidl. Stabilizing Branch-and-Price for Constrained Tree Problems. Networks, 61(2):150-170, 2013.
    [Bibtex]
    @Article{Leitner2013,
    Title = {Stabilizing Branch-and-Price for Constrained Tree Problems},
    Author = {Leitner, Markus and Ruthmair, Mario and Raidl, G{\"u}nther R.},
    Journal = {Networks},
    Year = {2013},
    Number = {2},
    Pages = {150--170},
    Volume = {61},
    Doi = {10.1002/net.21484},
    File = {:pdfs-own/Leitner2013.pdf:PDF},
    Timestamp = {2015.05.23}
    }

Book Chapters

  1. [PDF] [DOI] Georg Brandstätter, Claudio Gambella, Markus Leitner, Enrico Malaguti, Filippo Masini, Jakob Puchinger, Mario Ruthmair, and Daniele Vigo. Overview of Optimization Problems in Electric Car-Sharing System Design and Management. In Herbert Dawid, Karl F. Doerner, Gustav Feichtinger, Peter M. Kort, and Andrea Seidl, editors, Dynamic Perspectives on Managerial Decision Making, volume 22 of Dynamic Modeling and Econometrics in Economics and Finance, pages 441-471. Springer, Berlin, 2016.
    [Bibtex]
    @InCollection{Brandstaetter2016,
    Title = {Overview of Optimization Problems in Electric Car-Sharing System Design and Management},
    Author = {Georg Brandst{\"{a}}tter and Claudio Gambella and Markus Leitner and Enrico Malaguti and Filippo Masini and Jakob Puchinger and Mario Ruthmair and Daniele Vigo},
    Booktitle = {Dynamic Perspectives on Managerial Decision Making},
    Publisher = {Springer, Berlin},
    Year = {2016},
    Editor = {Herbert Dawid and Karl F. Doerner and Gustav Feichtinger and Kort, Peter M. and Andrea Seidl},
    Pages = {441--471},
    Series = {Dynamic Modeling and Econometrics in Economics and Finance},
    Volume = {22},
    Doi = {10.1007/978-3-319-39120-5_24},
    File = {:pdfs-own/Brandstaetter2016.pdf:PDF},
    Timestamp = {2016-11-330}
    }
  2. [PDF] Luis Gouveia, Mario Ruthmair, and Daniel Santos. Um modelo de fluxo para o electric traveling salesman problem. In C. H. Antunes, D. M. Cardoso, and F. N. da Silva, editors, A Investigação Operacional em Portugal – novos desafios novas ideias, homenagem ao Professor Luís Valadares Tavares, pages 133-143. IST Press, Lisboa, 2016.
    [Bibtex]
    @InCollection{Gouveia2016,
    Title = {Um modelo de fluxo para o electric traveling salesman problem},
    Author = {Gouveia, Luis and Ruthmair, Mario and Santos, Daniel},
    Booktitle = {A Investiga{\c{c}}\~ao Operacional em {Portugal} - novos desafios novas ideias, homenagem ao Professor Lu{\'{i}}s Valadares Tavares},
    Publisher = {IST Press, Lisboa},
    Year = {2016},
    Editor = {Antunes, C.H. and Cardoso, D.M. and da Silva, F.N.},
    Pages = {133--143},
    File = {:pdfs-own/Gouveia2016.pdf:PDF},
    Timestamp = {2016-05-145}
    }

Refereed Conference Papers

  1. [PDF] [DOI] Matthias Prandtstetter, Ulrike Ritzinger, Peter Schmidt, and Mario Ruthmair. A Variable Neighborhood Search Approach for the Interdependent Lock Scheduling Problem. In Gabriela Ochoa and Francisco Chicano, editors, Evolutionary Computation in Combinatorial Optimization, volume 9026 of LNCS, pages 36-47. Springer, 2015.
    [Bibtex]
    @InProceedings{Prandtstetter2015,
    Title = {A Variable Neighborhood Search Approach for the Interdependent Lock Scheduling Problem},
    Author = {Prandtstetter, Matthias and Ritzinger, Ulrike and Schmidt, Peter and Ruthmair, Mario},
    Booktitle = {Evolutionary Computation in Combinatorial Optimization},
    Year = {2015},
    Editor = {Ochoa, Gabriela and Chicano, Francisco},
    Pages = {36--47},
    Publisher = {Springer},
    Series = {LNCS},
    Volume = {9026},
    Doi = {10.1007/978-3-319-16468-7_4},
    File = {:pdfs-own/Prandtstetter2015.pdf:PDF},
    Timestamp = {2015.05.23}
    }
  2. [PDF] [DOI] Martin Berlakovich, Mario Ruthmair, and Günther R. Raidl. A Multilevel Heuristic for the Rooted Delay-Constrained Minimum Spanning Tree Problem. In R. Moreno-Díaz, F. Pichler, and A. Quesada-Arencibia, editors, Proceedings of the 13th International Conference on Computer Aided Systems Theory: Part I, volume 6927 of LNCS, pages 256-263. Springer, 2012.
    [Bibtex]
    @InProceedings{Berlakovich2012,
    Title = {A Multilevel Heuristic for the Rooted Delay-Constrained Minimum Spanning Tree Problem},
    Author = {Berlakovich, Martin and Ruthmair, Mario and Raidl, G{\"u}nther R.},
    Booktitle = {Proceedings of the 13th International Conference on Computer Aided Systems Theory: Part I},
    Year = {2012},
    Editor = {Moreno-D{\'i}az, R. and Pichler, F. and Quesada-Arencibia, A.},
    Pages = {256--263},
    Publisher = {Springer},
    Series = {LNCS},
    Volume = {6927},
    Doi = {10.1007/978-3-642-27549-4_33},
    File = {:pdfs-own/Berlakovich2012.pdf:PDF},
    Timestamp = {2015.05.23}
    }
  3. [PDF] [DOI] Thorsten Krenek, Mario Ruthmair, and Günther R. Raidl. Applying (Hybrid) Metaheuristics to Fuel Consumption Optimization of Hybrid Electric Vehicles. In Di C. Chio and others, editors, Proceedings of the European Conference on the Applications of Evolutionary Computation, volume 7248 of LNCS, pages 376-385. Springer, 2012.
    [Bibtex]
    @InProceedings{Krenek2012,
    Title = {Applying (Hybrid) Metaheuristics to Fuel Consumption Optimization of Hybrid Electric Vehicles},
    Author = {Krenek, Thorsten and Ruthmair, Mario and Raidl, G{\"u}nther R.},
    Booktitle = {Proceedings of the European Conference on the Applications of Evolutionary Computation},
    Year = {2012},
    Editor = {Chio, C. Di and others},
    Pages = {376--385},
    Publisher = {Springer},
    Series = {LNCS},
    Volume = {7248},
    Doi = {10.1007/978-3-642-29178-4_38},
    File = {:pdfs-own/Krenek2012.pdf:PDF},
    Timestamp = {2015.05.23}
    }
  4. [PDF] [DOI] Mario Ruthmair and Günther R. Raidl. On Solving the Rooted Delay- and Delay-Variation-Constrained Steiner Tree Problem. In A. R. Mahjoub and others, editors, Proceedings of the 2nd International Symposium on Combinatorial Optimization, volume 7422 of LNCS, pages 225-236. Springer, 2012.
    [Bibtex]
    @InProceedings{Ruthmair2012a,
    Title = {On Solving the Rooted Delay- and Delay-Variation-Constrained Steiner Tree Problem},
    Author = {Ruthmair, Mario and Raidl, G{\"u}nther R.},
    Booktitle = {Proceedings of the 2nd International Symposium on Combinatorial Optimization},
    Year = {2012},
    Editor = {Mahjoub, A.R. and others},
    Pages = {225--236},
    Publisher = {Springer},
    Series = {LNCS},
    Volume = {7422},
    Doi = {10.1007/978-3-642-32147-4_21},
    File = {:pdfs-own/Ruthmair2012a.pdf:PDF},
    Timestamp = {2015.05.23}
    }
  5. [PDF] [DOI] Mario Ruthmair and Günther R. Raidl. A Memetic Algorithm and a Solution Archive for the Rooted Delay-Constrained Minimum Spanning Tree Problem. In R. Moreno-Díaz, F. Pichler, and A. Quesada-Arencibia, editors, Proceedings of the 13\textsuperscriptth International Conference on Computer Aided Systems Theory: Part I, volume 6927 of LNCS, pages 351-358. Springer, 2012.
    [Bibtex]
    @InProceedings{Ruthmair2012b,
    Title = {A Memetic Algorithm and a Solution Archive for the Rooted Delay-Constrained Minimum Spanning Tree Problem},
    Author = {Ruthmair, Mario and Raidl, G{\"u}nther R.},
    Booktitle = {Proceedings of the 13\textsuperscript{th} International Conference on Computer Aided Systems Theory: Part I},
    Year = {2012},
    Editor = {Moreno-D{\'i}az, R. and Pichler, F. and Quesada-Arencibia, A.},
    Pages = {351--358},
    Publisher = {Springer},
    Series = {LNCS},
    Volume = {6927},
    Doi = {10.1007/978-3-642-27549-4_45},
    File = {:pdfs-own/Ruthmair2012b.pdf:PDF},
    Timestamp = {2015.05.23}
    }
  6. [PDF] [DOI] Markus Leitner, Mario Ruthmair, and Günther R. Raidl. Stabilized Branch-and-Price for the Rooted Delay-Constrained Steiner Tree Problem. In J. Pahl, T. Reiners, and S. Voß, editors, Network Optimization: 5th International Conference, INOC 2011, volume 6701 of LNCS, pages 124-138, Hamburg, Germany, 2011. Springer.
    [Bibtex]
    @InProceedings{Leitner2011,
    Title = {Stabilized Branch-and-Price for the Rooted Delay-Constrained {S}teiner Tree Problem},
    Author = {Leitner, Markus and Ruthmair, Mario and Raidl, G{\"u}nther R.},
    Booktitle = {Network Optimization: 5th International Conference, INOC 2011},
    Year = {2011},
    Address = {Hamburg, Germany},
    Editor = {Pahl, J. and Reiners, T. and Vo{\ss}, S.},
    Pages = {124--138},
    Publisher = {Springer},
    Series = {LNCS},
    Volume = {6701},
    Doi = {10.1007/978-3-642-21527-8_16},
    File = {:pdfs-own/Leitner2011.pdf:PDF},
    Timestamp = {2015.05.23}
    }
  7. [PDF] Markus Leitner, Mario Ruthmair, and Günther R. Raidl. Stabilized Column Generation for the Rooted Delay-Constrained Steiner Tree Problem. In Proceedings of the VII ALIO/EURO — Workshop on Applied Combinatorial Optimization, pages 250-253, Porto, Portugal, 2011.
    [Bibtex]
    @InProceedings{Leitner2011a,
    Title = {Stabilized Column Generation for the Rooted Delay-Constrained {S}teiner Tree Problem},
    Author = {Leitner, Markus and Ruthmair, Mario and Raidl, G{\"u}nther R.},
    Booktitle = {Proceedings of the VII ALIO/EURO -- Workshop on Applied Combinatorial Optimization},
    Year = {2011},
    Address = {Porto, Portugal},
    Pages = {250--253},
    File = {:pdfs-own/Leitner2011a.pdf:PDF},
    Timestamp = {2015-01-26}
    }
  8. [PDF] [DOI] Mario Ruthmair and Günther R. Raidl. A Layered Graph Model and an Adaptive Layers Framework to Solve Delay-Constrained Minimum Tree Problems. In O. Günlük and G. J. Woeginger, editors, Proceedings of the 15th Conference on Integer Programming and Combinatorial Optimization (IPCO XV), volume 6655 of LNCS, pages 376-388. Springer, 2011.
    [Bibtex]
    @InProceedings{Ruthmair2011a,
    Title = {A Layered Graph Model and an Adaptive Layers Framework to Solve Delay-Constrained Minimum Tree Problems},
    Author = {Ruthmair, Mario and Raidl, G{\"u}nther R.},
    Booktitle = {Proceedings of the 15th Conference on Integer Programming and Combinatorial Optimization (IPCO XV)},
    Year = {2011},
    Editor = {G{\"u}nl{\"u}k, O. and Woeginger, G.J.},
    Pages = {376--388},
    Publisher = {Springer},
    Series = {LNCS},
    Volume = {6655},
    Doi = {10.1007/978-3-642-20807-2_30},
    File = {:pdfs-own/Ruthmair2011a.pdf:PDF},
    Timestamp = {2015.05.23}
    }
  9. [PDF] [DOI] Mario Ruthmair and Günther R. Raidl. Variable Neighborhood Search and Ant Colony Optimization for the Rooted Delay-Constrained Minimum Spanning Tree Problem. In R. Schaefer and others, editors, Proceedings of the 11th International Conference on Parallel Problem Solving from Nature: Part II, volume 6239 of LNCS, pages 391-400. Springer, 2010.
    [Bibtex]
    @InProceedings{Ruthmair2010,
    Title = {Variable Neighborhood Search and Ant Colony Optimization for the Rooted Delay-Constrained Minimum Spanning Tree Problem},
    Author = {Ruthmair, Mario and Raidl, G{\"u}nther R.},
    Booktitle = {Proceedings of the 11th International Conference on Parallel Problem Solving from Nature: Part II},
    Year = {2010},
    Editor = {Schaefer, R. and others},
    Pages = {391--400},
    Publisher = {Springer},
    Series = {LNCS},
    Volume = {6239},
    Doi = {10.1007/978-3-642-15871-1_40},
    File = {:pdfs-own/Ruthmair2010.pdf:PDF},
    Timestamp = {2015.05.23}
    }
  10. [PDF] [DOI] Mario Ruthmair and Günther R. Raidl. A Kruskal-Based Heuristic for the Rooted Delay-Constrained Minimum Spanning Tree Problem. In R. Moreno-Díaz, F. Pichler, and A. Quesada-Arencibia, editors, Proceedings of the 12th International Conference on Computer Aided Systems Theory, volume 5717 of LNCS, pages 713-720. Springer, 2009.
    [Bibtex]
    @InProceedings{Ruthmair2009,
    Title = {A Kruskal-Based Heuristic for the Rooted Delay-Constrained Minimum Spanning Tree Problem},
    Author = {Ruthmair, Mario and Raidl, G{\"u}nther R.},
    Booktitle = {Proceedings of the 12th International Conference on Computer Aided Systems Theory},
    Year = {2009},
    Editor = {Moreno-D{\'i}az, R. and Pichler, F. and Quesada-Arencibia, A.},
    Pages = {713--720},
    Publisher = {Springer},
    Series = {LNCS},
    Volume = {5717},
    Doi = {10.1007/978-3-642-04772-5_92},
    File = {:pdfs-own/Ruthmair2009.pdf:PDF},
    Timestamp = {2015.05.23}
    }
  11. [PDF] [DOI] Jakob Walla, Mario Ruthmair, and Günther R. Raidl. Solving a Video-Server Load Re-Balancing Problem by Mixed Integer Programming and Hybrid Variable Neighborhood Search. In M. J. Blesa and others, editors, Hybrid Metaheuristics 2009, volume 5818 of LNCS, pages 84-99. Springer, 2009.
    [Bibtex]
    @InProceedings{Walla2009a,
    Title = {Solving a Video-Server Load Re-Balancing Problem by Mixed Integer Programming and Hybrid Variable Neighborhood Search},
    Author = {Walla, Jakob and Ruthmair, Mario and Raidl, G{\"u}nther R.},
    Booktitle = {Hybrid Metaheuristics 2009},
    Year = {2009},
    Editor = {Blesa, M. J. and others},
    Pages = {84--99},
    Publisher = {Springer},
    Series = {LNCS},
    Volume = {5818},
    Doi = {10.1007/978-3-642-04918-7_7},
    File = {:pdfs-own/Walla2009a.pdf:PDF},
    Timestamp = {2015.05.23}
    }

Technical Reports

  1. [PDF] Markus Leitner, Ivana Ljubić, Martin Riedler, and Mario Ruthmair. Exact Approaches for Network Design Problems with Relays. Technical Report AC-TR-15-003, Algorithms and Complexity Group, Vienna University of Technology, Vienna, Austria, 2015. submitted to a journal
    [Bibtex]
    @TechReport{Leitner2015,
    Title = {Exact Approaches for Network Design Problems with Relays},
    Author = {Markus Leitner and Ivana Ljubi{\'{c}} and Martin Riedler and Mario Ruthmair},
    Institution = {Algorithms and Complexity Group, Vienna University of Technology},
    Year = {2015},
    Address = {Vienna, Austria},
    Note = {submitted to a journal},
    Number = {AC-TR-15-003},
    File = {:pdfs-own/Leitner2015.pdf:PDF},
    Timestamp = {2016-01-05}
    }

Theses

  1. [PDF] Mario Ruthmair. On Solving Constrained Tree Problems and an Adaptive Layers Framework. PhD thesis, Vienna University of Technology, Institute of Computer Graphics and Algorithms, Vienna, Austria, 2012. supervised by G.R. Raidl and U. Pferschy
    [Bibtex]
    @PhdThesis{Ruthmair2012,
    Title = {On Solving Constrained Tree Problems and an Adaptive Layers Framework},
    Author = {Ruthmair, Mario},
    School = {Vienna University of Technology, Institute of Computer Graphics and Algorithms},
    Year = {2012},
    Address = {Vienna, Austria},
    Month = may,
    Note = {supervised by G.R. Raidl and U. Pferschy},
    File = {:pdfs-own/Ruthmair2012.pdf:PDF},
    Pages = {187},
    Timestamp = {2015-01-26}
    }
  2. [PDF] Mario Ruthmair. Gateway zur Übertragung von Audiodaten von einem RTSP-Server in ein IEEE1394-Netzwerk. Master’s thesis, Vienna University of Technology, Institute of Computer Technology, Vienna, Austria, 2006.
    [Bibtex]
    @MastersThesis{Ruthmair2006,
    Title = {Gateway zur {\"U}bertragung von Audiodaten von einem RTSP-Server in ein IEEE1394-Netzwerk},
    Author = {Ruthmair, Mario},
    School = {Vienna University of Technology, Institute of Computer Technology},
    Year = {2006},
    Address = {Vienna, Austria},
    Month = mar,
    File = {:pdfs-own/Ruthmair2006.pdf:PDF},
    Timestamp = {2015-01-26}
    }