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Julien Straubhaar

My main research topic is the geostatistics. I'm developing new Multiple-Point Statistics (MPS) algorithms. MPS allows to generate complex heterogeneous fields in a stochastic framework by integrating a conceptual model (training image). This is a crucial issue in geostatistical simulations because the spatial features of geological structures have a deep impact on the dynamic processes (flow / transport).

Impala and DeeSse are two Multiple-Point Statistics Softwares developed in the Stochastic Hydrogeology Group.

  • Impala : written in C, serial version and parallel versions: OpenMP (for shared memory machines) / MPI (for distributed memory machines (HPC cluster))
  • DeeSse : written in C, serial version and parallel versions: OpenMP (for shared memory machines) / CUDA (for shared memory machines equipped with GPUs)

Education 

  • 2007 - Doctorat ès Sciences (PhD.), Université de Neuchâtel (mathématiques appliquées)
  • 2002 - Diplôme de mathématicien (MSc.), Université de Neuchâtel

 

Positions held

  • 2009 - now  - Maître-assistant (Senior Lecturer) au Centre d'Hydrogéologie et de Géothermie (CHYN), Université de Neuchâtel, Switzerland
  • 2007 - 2009 - Postdoc au Centre d'Hydrogéologie et de Géothermie (CHYN), Université de Neuchâtel, Switzerland
  • 2002 - 2007 - Assistant-doctorant (PhD student) à l'institut de mathématiques, Université de Neuchâtel, Switzerland
  • 2001 - 2002 - Assistant (non dipômé) à l'institut de mathématiques, Université de Neuchâtel, Switzerland

 

Publications

  • J. Straubhaar, P. Renard, G. Mariethoz (2016) Conditioning multiple-point statistics simulations to block data. Spatial Statistics 16, 53-71, DOI: 10.1016/j.spasta.2016.02.005
  • G. Pirot, J. Straubhaar, P. Renard (2015) A pseudo genetic model of coarse braided-river deposits. Water Resour. Res. 51(12), 9595-9611, DOI: 10.1002/2015WR017078
  • G. Pirot, P. Renard, E. Huber, J. Straubhaar, P. Huggenberger (2015) Influence of conceptual Model uncertainty on contaminant transport forecasting in braided river aquifers. J. Hydrol. 531(1, SI), 124-141, DOI: 10.1016/j.jhydrol.2015.07.036
  • G. Mariethoz, J. Straubhaar, P. Renard, T. Chugunova, P. Biver (2015) Constraining distance-based multipoint simulations to proportions and trends. Environ Modell Softw 72, 184-197, DOI: 10.1016/j.envsoft.2015.07.007
  • N. Dickson, J.-C. Comte, P. Renard, J. Straubhaar, J. McKinley, U. Ofterdinger (2015) Integrating aerial geophysical data in multiple-point statistics simulations to assist groundwater flow models. Hydrogeol J 23 (5), 883-900, DOI: 10.1007/s10040-015-1258-x
  • T. Lochbühler, G. Pirot, J. Straubhaar, N. Linde (2014) Conditioning of multiple-point statistics facies simulations to tomographic images. Math Geosci 46 (5), 625-645, DOI: 10.1007/s11004-013-9484-z
  • G. Pirot, J. Straubhaar, P. Renard (2014) Simulation of braided river elevation model time series with multiple-point statistics. Geomorphology 214, 148-156, DOI: 10.1016/j.geomorph.2014.01.022
  • J. Straubhaar, D. Malinverni (2014) Addressing conditioning data in multiple-point statistics simulation algorithms based on a multiple grid approach. Math Geosci 46 (2), 187-204, DOI: 10.1007/s11004-013-9479-9
  • F. Oriani, J. Straubhaar, P. Renard, G. Mariethoz (2014) Simulation of rainfall time series from different climatic regions using the direct sampling technique. Hydrol Earth Syst Sc 18, 3015-3031, DOI: 10.5194/hess-18-3015-2014
  • E. Meerschman, G. Pirot, G. Mariethoz, J. Straubhaar, M. Van Meirvenne, P. Renard (2013) A practical guide to performing multiple-point statistical simulations with the Direct Sampling algorithm. Comput Geosci 52, 307-324, DOI: 10.1016/j.cageo.2012.09.019
  • J. Straubhaar, A. Walgenwitz, P. Renard (2013) Parallel Multiple-point Statistics Algorithm Based on List and Tree Structures. Math Geosci 45 (2), 131-147, DOI: 10.1007/s11004-012-9437-y
  • A. Comunian, P. Renard, J. Straubhaar (2012) 3D multiple-point statistics simulation using 2D training images. Comput Geosci 40, 49-65, DOI: 10.1016/j.cageo.2011.07.009
  • P. Renard,  J. Straubhaar, J. Caers, G. Mariethoz (2011) Conditioning Facies Simulations with Connectivity Data. Math Geosci 43 (8), 879-903, DOI: 10.1007/s11004-011-9363-4
  • G. Mariethoz, P. Renard, J. Straubhaar (2011) Extrapolating the Fractal Characteristics of an Image Using Scale-Invariant Multiple-Point Statistics. Math Geosci 43 (7), 783-797, DOI: 10.1007/s11004-011-9362-5
  • A. Comunian, P. Renard, J. Straubhaar, P. Bayer (2011) Three-dimensional high resolution fluvio-glacial aquifer analog - Part 2: Geostatistical modeling. J Hydrol 405 (1-2), 10-23, DOI: 10.1016/j.jhydrol.2011.03.037
  • J. Straubhaar, P. Renard, G. Mariethoz, R. Froidevaux, O. Besson (2011) An Improved Parallel Multiple-Point Algorithm Using a List Approach. Math Geosci 43 (3), 305-328, DOI: 10.1007/s11004-011-9328-7
  • G. Mariethoz, P. Renard, J. Straubhaar (2010) The Direct Sampling method to perform multiple-point geostatistical simulations. Water Resour Res 46, W11536, DOI: 10.1029/2008WR007621
  • J. Straubhaar (2008) Parallel preconditioners for the conjugate gradient algorithm using Gram-Schmidt and least squares methods. Parallel Comput 34 (10), 551-569, DOI: 10.1016/j.parco.2008.06.001
  • J. Straubhaar (2007) Preconditioners for the conjugate gradient algorithm using Gram-Schmidt and least squares methods. Int J Comput Math 84 (1), 89-108, DOI: 10.1080/00207160601173621
  • J. Straubhaar (2007) Préconditionnement de systèmes linéaires symétriques définis positifs. Application à la simulation numérique d'écoulements océaniques tridimensionnels. Ph.D. Thesis, Université de Neuchâtel, link

 

 

Contact

 

Office: E324

Tél. : +41 32 718 26 10
 

 

Centre d'hydrogéologie
Rue Emile-Argand 11
2000 Neuchâtel