Welcome on my webpage!
I am an assistant professor at Strasbourg University, France since October 1st, 2009.
To contact me, send me an email!
Email:
geffray(at)math.unistra.fr
Research interests
I am currently interested in:
- Statistical inference from image data:
- Getting rid simultaneously of uneven illumination and noise
- Objects detection by means of stochastic algorithms for spatial models
- Morphological characterization from 2D images
- Applications to biomaterial modeling for tissue engineering
- Image quality objective criterion
- Statistical inference from functional data:
- Functional semiparametric regression with a Bayesian methodology
- Applications to cell growth data analysis
- Applications to circadian rhythms data analysis
Before that, I have been working on the following subjects:
- Estimation of lifetime distributions in the presence of censoring
- Competing risks and recurrent events
- Non-parametric inference and semi-parametric models from duration data
- Extreme value theory (momentarily)
Publications
My published papers are here:
- Dang H.-P., Vimond M., Geffray S. (2021), Data-Driven Parameter Choice for Illumination Artifact Correction of Digital Images , IEEE Signal Processing Letters, 28: 155-159
- Geffray S., Klutchnikoff N., Vimond M. (2016), Illumination problems in digital images. A statistical point of view, J. Mult. Anal., 150: 191-213
- Bouaziz O., Geffray S., Lopez O. (2015), Semiparametric inference for the recurrent events process by means of a single-index model, Statistics, 49(2): 361-385
- Geffray S. (2013), Modeling and inferential thoughts for consecutive gap times observed with death and censoring, Invited paper in the special issue of the Journal of the Iranian Statistical Society on recurrent events, 12 (1):71-112
- Geffray S., Guilloux A. (2011), Maximum likelihood estimator for cumulative incidence functions under proportionality constraint, Sankhya, series A, 73 (2): 303-328
- Beirlant J., Geffray S., Guillou A. (2011), Estimation of the bias of the maximum likelihood estimators in an extreme value context, Comm. Statist. Theory Meth., 40 (22): 3959-3971
- Geffray S. (2009), Strong approximations for dependent competing risks with independent censoring with statistical applications, TEST, 18 (1): 76-95
- Geffray S. (2007), Estimation dans un modèle de risques concurrents éventuellement dépendants en présence de censure, C. R. Acad. Sci. Paris, Ser. I, 344: 457-460
- Geffray S., Guilloux A. (2005), Estimation dans un modèle de Koziol-Green généralisé, C. R. Acad. Sci. Paris, Ser. I, 341: 49-52
Some preprints are here:
- Coiffard-Marre C., Geffray S. (2015), Object detection and automatic measurements with a data-driven algorithm for marked point process optimization, working paper
- Bouaziz O., Geffray S., Lopez O. (2010), Semiparametric inference for the recurrent event process by means of a single-index model , working paper
- Geffray S. (2007), Strong approximations for dependent competing risks with independent censorship, working paper
My Ph.Thesis is here: (it is written in english but the general introduction is in french)
- Ph.Thesis, University Paris 6, France
Non-parametric estimation from censored data in a multi-state framework