Hanna Jankowski

[Contact] [Teaching] [Supervision] [Research] [Software]

My main research interests are in nonparametric and semi-parametric statistics.

A considerable amount of my recent work is in shape-constrained maximum likelihood estimation. The key idea behind this approach is to strike a balance between parametric methods and purely nonparametric methods by specifying a shape (e.g. convexity) of the function of interest. Unlike kernel smoothing methods, shape-constrained methodology does not require a choice of bandwidth, as it is automatically locally adaptive.

I am also interested in statistical inference for random sets. Random sets are a natural approach to the analysis of shapes, and do not require user-defined landmarks, making them more natural in certain contexts. A closely associated work is the Bayesian approach to principal curves described here, which shows an application to the analysis of SPECT medical imaging data.

My interest in random sets has recently led to research in effective dose estimation in the multivariate setting. When more than one agent is present, the effective dose estimator is essentially a random set. Thus far, my research has focused on developing practical confidence regions in the multivariate setting.

I am also interested in applied and collaborative work. Some recent/current projects include flightpath recovery for migrating songbirds and clustering of the H3N2 flu virus.

Publications:

Trainees are underlined. Publications listed by year are available here.

SHAPE-CONSTRAINED MAXIMUM LIKELIHOOD METHODS:

  • Fadoua Balabdaoui, Hanna Jankowski, "Maximum likelihood estimation of a unimodal probability mass function" (2015) To appear in Statistica Sinica. [PDF][R code for simulations and data analysis]
  • Rihong Hui, Hanna Jankowski, "CPHshape: estimating a shape constrained baseline hazard in the Cox proportional hazards model", submitted. [PDF][CPHshape]
  • Mahdis Azadbakhsh, Hanna Jankowski, Xin Gao (2014) "Calculating confidence intervals for log-concave densities," Computational Statistics and Data Analysis 75 248-264 [preprint][supplement][logcondens]
  • Hanna Jankowski (2014) "Convergence of linear functionals of the Grenander estimator under misspecification", Annals of Statistics 42 (2) 635-653 [preprint][R code]
  • Fadoua Balabdaoui, Hanna Jankowski, Kaspar Rufibach, M.Palvides (2013) "Asymptotics of the discrete log-concave maximum likelihood estimator and related applications", Journal of the Royal Statistical Society, Series B 75 (4) 769-790 [arXiv][logcondiscr]
  • Hanna Jankowski (2010), Invited discussion of "Maximum likelihood estimation of a multi-dimensional log-concave density" by Cule, Samworth, and Stewart, Journal of the Royal Statistical Society: Series B 72, part 5, 596-597. [PDF]
  • Fadoua Balabdaoui, Hanna Jankowski, Marios Pavlides, Arseni Seregin, Jon Wellner (2011), "On the Grenander estimator at zero", Statistica Sinica 21 (2), 873-899. [PDF]
  • Hanna K. Jankowski and Jon A. Wellner (2009), "Estimation of a discrete monotone distribution", Electronic Journal of Statistics 3, 1567-1605. [PDF] [R code]
  • Hanna K. Jankowski and Jon A. Wellner (2009), "Nonparametric estimation of a convex bathtub-shaped hazard function", Bernoulli 15 (4), 1010-1035. [PDF] [longer version] [convexHaz]
  • Hanna K. Jankowski and Jon A. Wellner (2009), "Computation of nonparametric convex hazard estimators via profile methods", Journal of Nonparametric Statistics 21, 505-518. [tech report] [convexHaz]

EFFECTIVE DOSE:

  • Hanna Jankowski, Xiang Ji, Larissa Stanberry, "A random set approach to confidence regions with applications to the effective dose with combinations of agents" (2014), Statistics in Medicine 33 4266-4278. [preprint][supplement][very early preprint (more mathy)][matlab script]

STATISTICAL INFERENCE FOR RANDOM SETS (and associated work):

  • Hanna Jankowski, Larissa Stanberry (2014) "Visualizing variability: confidence regions in level set estimation", Proceedings of the 16th International Conference on Geometry and Garphics, 1328-1339. [PDF][code for Example 5][code for Example 6]
  • Hanna Jankowski and Larissa Stanberry (2012), "Confidence regions for means of random sets using oriented distance functions", Scandinavian Journal of Statistics 39 (2) 340-357 [preprint] [sand grains data]
  • Hanna Jankowski and Larissa Stanberry (2012), "Identifying skeleton curves in noisy data," Communications in Statistics: Theory and Methods 41 (6) 852-864 [preprint]
  • Hanna K. Jankowski and Larissa I. Stanberry (2010), "Expectations of random sets and their boundaries using oriented distance functions", Journal of Mathematical Imaging and Vision 36 (3), 291-303.

COMPOSITE LIKELIHOOD:

  • Mahdis Azadbakhsh, Xin Gao, Hanna Jankowski, "Multiple Comparisons Using Composite Likelihood in Clustered Data" (2016) to appear in the International Journal of Biostatistics. [PDF][code for simulations][arXiv]

APPLIED, COLLABORATIVE, AND INDUSTRIAL WORK:

  • X.Li, H.Jankowski, S.Boonpatcharanon, V.Tran, X.Wang, J.Heffernan "Clustering Neuraminidase Influenza Protein Sequences", submitted. [PDF][data]
  • Mirzo Kanoatov, Victor Galievsky, Svetlana Krylova, Leonid Cherney, Hanna Jankowski, Sergey Krylov (2015) "Using Non-Equilibrium Capillary Electrophoresis of Equilibrium Mixtures (NECEEM) for Simultaneous Determination of Concentration and Equilibrium Constant," Analytical Chemistry 87 3099-3106.
  • Xuan Li, Hanna Jankowski, Steven Wang, Jane Heffernan, "A method for clustering Hemaglutinin protein sequences," (2015) to appear in BIOMAT 2014 Proceedings, [PDF][data]
  • Barb Veder, Amanda Tian, Kelly Beaudoin, Linda Bettencourt, Karina Dunmarra, Yolanda Fasciano, Julia Marinos, Georges Monette, Hanna Jankowski (2014); "Re-examining access patterns and user demographics of online service offerings", industrial report.
  • Jeremy Recoskie, Jane Heffernan, Hanna Jankowski, "A note on statistical and biological communication: case study of the 2009 H1N1 pandemic" (2014), to appear in BMC Research Notes.
  • Hanna Jankowski, Veronica Sabelnykova, John Sheriff (2011) Estimating the wintering location of the wood thrush. Technical Report. [PDF]

OLDER PAPERS AND DISCUSSIONS:

  • Xin Gao and Hanna Jankowski (2012), Invited discussion of "Catching up faster by switching sooner: a predictive approach to adaptive estimation with an application to the AIC-BIC dilemma" by van Erven et.al., Journal of the Royal Statistical Society: Series B 74 (3), 405. [PDF]
  • Hanna Jankowski (2012), Invited discussion of "Statistical Methods for Healthcare Regulation: Rating, Screening and Surveillance" by Spiegelhalter et. al., Journal of the Royal Statistical Society: Series A 175 (1), 36-37. [PDF]
  • Jeremy Quastel, Hanna Jankowski, John Sheriff (2002), "Central limit theorem for zero-range processes", Methods and Applications of Analysis 9 (8), 393-406. [PDF]