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Accès public à partir du 31 mai 2019
Université de Neuchâtel

Random partitioning and adaptive filters for multiple-point stochastic simulation

Sharifzadehlari, M ; Fathianpour, N ; Renard, Philippe ; Amirfattahi, R

In: Stochastic Environmental Research and Risk Assessment, 2018, vol. 32, p. 1375-1396

Multiple-point geostatistical simulation is used to simulate the spatial structures of geological phenomena. In contrast to conventional two-point variogram based geostatistical methods, the multiple-point approach is capable of simulating complex spatial patterns, shapes, and structures normally observed in geological media. A commonly used pattern based multiple-point geostatistical simulation...

Accès public à partir du 15 mai 2019
Université de Neuchâtel

Simulating rainfall time-series : how to account for statistical variability at multiple scales?

Oriani, Fabio ; Mehrotra, R ; Mariéthoz, Grégoire ; Straubhaar, Julien ; Sharma, A ; Renard, Philippe

In: Stochastic Environmental Research and Risk Assessment, 2018, vol. 32, p. 321-340

Daily rainfall is a complex signal exhibiting alternation of dry and wet states, seasonal fluctuations and an irregular behavior at multiple scales that cannot be preserved by stationary stochastic simulation models. In this paper, we try to investigate some of the strategies devoted to preserve these features by comparing two recent algorithms for stochastic rainfall simulation: the first one is...

Accès public à partir du 24 févr. 2020
Université de Neuchâtel

Can one identify karst conduit networks geometry and properties from hydraulic and tracer test data?

Borghi, Andrea ; Renard, Philippe ; Cornaton, Fabien

In: Advances in Water Resources, 2016, vol. 90, p. 99-115

Karst aquifers are characterized by extreme heterogeneity due to the presence of karst conduits embedded in a fractured matrix having a much lower hydraulic conductivity. The resulting contrast in the physical properties of the system implies that the system reacts very rapidly to some changes in the boundary conditions and that numerical models are extremely sensitive to small modifications in...

Université de Neuchâtel

Fractal Dimension, Walk Dimension and Conductivity Exponent of Karst Networks around Tulum

Hendrick, M ; Renard, Philippe

In: Frontiers in Physics, 2016, vol. 4, p. 27

Understanding the complex structure of karst networks is a challenge. In this work, we characterize the fractal properties of some of the largest coastal karst network systems in the world. They are located near the town of Tulum (Quintana Roo, Mexico). Their fractal dimension df, conductivity exponent μ∼ and walk dimension dw are estimated using real space...

Université de Neuchâtel

Subnetworks of Percolation Backbones to Model Karst Systems Around Tulum, Mexico

Hendrick, M ; Renard, Philippe

In: Frontiers in Physics, 2016, vol. 4, p. 43

Karstic caves, which play a key role in groundwater transport, are often organized as complex connected networks resulting from the dissolution of carbonate rocks. In this work, we propose a new model to describe and study the structures of the two largest submersed karst networks in the world. Both of these networks are located in the area of Tulum (Quintana Roo, Mexico). In a previous work [1]...

Accès public à partir du 22 avr. 2020
Université de Neuchâtel

Comparing connected structures in ensemble of random fields

Rongier, G ; Collon, P ; Renard, Philippe ; Straubhaar, J ; Sausse, J

In: Advances in Water Resources, 2016, vol. 96, p. 145-169

Very different connectivity patterns may arise from using different simulation methods or sets of pa-rameters, and therefore different flow properties. This paper proposes a systematic method to compare ensemble of categorical simulations from a static connectivity point of view. The differences of static con-nectivity cannot always be distinguished using two point statistics. In addition,...

Accès public à partir du 14 janv. 2019
Université de Neuchâtel

Geothermal state of the deep Western Alpine Molasse Basin, France-Switzerland

Chelle-Michou, C ; Do Couto, D ; Moscariello, A ; Renard, Philippe ; Rusillon, E

In: Geothermics, 2017, vol. 67, p. 48-65

Over the last few years the Western Alpine Molasse Basin (WAMB) has been attracting large institutional, industrial and scientific interest to evaluate the feasibility of geothermal energy production. However, the thermal state of the basin, which is instrumental to the development of such geothermal projects, has remained to date poorly known. Here, we compile and correct temperature...

Université de Neuchâtel

Detection Test for Language Impairments in Adults and the Aged—A New Screening Test for Language Impairment Associated With Neurodegenerative Diseases: Validation and Normative Data

Macoir, Joël ; Fossard, Marion ; Lefebvre, Laurent ; Monetta, Laura ; Renard, Antoine ; Tran, Thi Mai ; Wilson, Maximiliano A.

In: American Journal of Alzheimer's Disease & Other Dementias, 2017, vol. 32, no. 17, p. 1-11

To date, there is no quick screening test that could be used during routine office visits to accurately assess language disorders in neurodegenerative diseases. To fill this important gap, we developed the Detection Test for Language impairments in Adults and the Aged (DTLA), a quick, sensitive, standardized screening test designed to assess language disorders in adults and the elderly...

Accès public à partir du 8 août 2018
Université de Neuchâtel

Inter-individual variability in discourse informativeness in elderly populations

Pistono, Aurélie ; Pariente, Jérémie ; Bézy, Catherine ; Pastor, Josette ; Tran, Thi Mai ; Renard, Antoine ; Fossard, Marion ; Jucla, Mélanie

In: Clinical Linguistics & Phonetics, 2017, vol. 31, no. 5, p. 1-18

An increasing number of studies focus on discourse production in patients with neurodegenerative diseases and underline its clinical usefulness. However, if this is to be used as a clinical tool, one needs to consider how normal discourse varies within cognitively unimpaired elderly populations. In the current study, the aim has been to investigate discourse macrolinguistic variability. For this,...

Université de Neuchâtel

Posterior population expansion for solving inverse problems

Jäggli, C ; Straubhaar, J ; Renard, Philippe

In: Water Resources Research, 2017, vol. 53, p. 2902-2916

Solving inverse problems in a complex, geologically realistic, and discrete model space and from a sparse set of observations is a very challenging task. Extensive exploration by Markov chain Monte Carlo (McMC) methods often results in considerable computational efforts. Most optimization methods, on the other hand, are limited to linear (continuous) model spaces and the minimization of an...