Research

Nikhil Singh's current picture

I completed my postdoc research under the mentorship of Dr. Marc Niethammer at the Department of Computer Science, at the University of North Carolina, Chapel Hill.

Before posdoc I did my PhD from the Scientific Computing and Imaging Institute (SCI), University of Utah. My dissertation advisors were Dr. Tom Fletcher and Dr. Sarang Joshi.

My graduate and postdoc research focussed on the statistical analysis of data with an emphasis on its geometry and topological characteristics. I developed manifold based methods of statistics to explain data that exhibit nonlinear variability and necessitate non-Euclidean analysis. Much of my time was spent in writing algorithms that used a mix of computational differential geometry, statistical machine learning, calculus of variations and numerical optimization.

For medical imaging applications, I have developed models for quantifying brain shape changes to build predictive models for growth and decline, for example, manifold regression models of aging human brain and neurological disorders. Other computer vision projects I was involved in included development of geodesic models for statistics on Grassmanian manifolds of linear subspaces.

Some of my other research exploits during postdoc research were in topological data analysis to characterize cell organization and arrangement in cancerous malignant tissues from highres histology images. I had been exploring methods derived from algebraic topology such as the persistent homology for imaging and vision applications.

Publications

- Nikhil Singh, Franc╠žois-Xavier Vialard, and Marc Niethammer.
Splines for Diffeomorphisms. (Among top 3 finalists for journal best paper award)
in J. Medical Image Analysis (MedIA), 2015. doi link
- Nikhil Singh, Jacob Hinkle, Sarang Joshi and P. Thomas Fletcther.
Hierarchical Geodesic Models for Diffeomorphisms.
in International Journal of Computer Vision (IJCV), 2015. doi link
- Yi Hong, Nikhil Singh, Roland Kwitt, Nuno Vasconcelos, and Marc Niethammer.
Parametric Regression on the Grassmannian.
in arXiv:1505.03832 2015.
- Xiaoxiao Liu, Marc Niethammer, Roland Kwitt, Nikhil Singh, M. McCormick, and Stephen Aylward.
Low-rank Atlas Image Analysis in the Presence of Pathologies.
in IEEE Transactions on Medical Imaging (IEEE TMI), 2015. doi link
- Yi Hong, Nikhil Singh, Roland Kwitt, and Marc Niethammer.
Group Testing for Longitudinal Data
in Information Processing in Medical Imaging (IPMI), 2015.
- Tian Cao, Nikhil Singh, Vladimir Jojic, and Marc Niethammer.
Semi-coupled dictionary learning for deformation prediction.
in IEEE International Symposium on Biomedical Imaging (ISBI), 2015.
- Nikhil Singh and Marc Niethammer
Splines for Diffeomorphic Image Regression. (Best paper runners up)
in Medical Image Computing and Computer-Assisted Intervention MICCAI 2014, Boston.
- Nikhil Singh, P. T. Fletcher, J. S. Preston, R. D. King, J. S. Marron, M. W. Weiner, and S. Joshi.
Quantifying Anatomical Shape Variations in Neurological Disorders.
in J. Medical Image Analysis (MedIA), 2014. doi:10.1016/j.media.2014.01.001
- Nikhil Singh, Heather D. Couture, J. S. Marron, Charles Perou, and Marc Niethammer
Topological Descriptors of Histology Images.
in Machine Learning in Medical Imaging MLMI 2014, Boston.
- Yi Hong, Nikhil Singh, Roland Kwitt and Marc Niethammer
Time-warped Geodesic Regression.
in Medical Image Computing and Computer-Assisted Intervention MICCAI 2014, Boston.
- Nikhil Singh, Jacob Hinkle, Sarang Joshi, and P. Thomas Fletcher.
An Efficient Parallel Algorithm for Hierarchical Geodesic Models in Diffeomorphisms.
in IEEE International Symposium on Biomedical Imaging (ISBI), 2014.
- Yi Hong, Roland Kwitt, Nikhil Singh, Brad Davis, Nuno Vasconcelos, and Marc Niethammer
Geodesic Regression on the Grassmanian.
in European Conference on Computer Vision (ECCV) 2014, Zurich.
- Hong Y, Davis B, Marron JS, Kwitt R, Singh N, Kimbell JS, Pitkin E, Superfine R, Davis SD, Zdanski CJ et al..
Statistical Atlas Construction via Weighted Functional Boxplots.
in J. Medical Image Analysis (MedIA), 2014.
- Nikhil Singh, Jacob Hinkle, Sarang Joshi, and P. Thomas Fletcher.
A Vector Momenta Formulation of Diffeomorphisms for Improved Geodesic Regression and Atlas Construction. (Best student paper award)
in IEEE International Symposium on Biomedical Imaging (ISBI), 2013.
- Nikhil Singh, Jacob Hinkle, Sarang Joshi, and P. Thomas Fletcher.
A Hierarchical Geodesic Model for Diffeomorphic Longitudinal Shape Analysis.
in Information Processing in Medical Imaging (IPMI), 2013.
- Miaomiao Zhang, Nikhil Singh, and P. Thomas Fletcher.
Bayesian Estimation of Regularization and Atlas Building in Diffeomorphic Image Registration.
in Information Processing in Medical Imaging (IPMI), 2013.
- Nikhil Singh, Angela Y. Wang, Preethi Sankaranarayanan, P. Thomas Fletcher, and Sarang Joshi.
Genetic, Structural and Functional Imaging Biomarkers for Early Detection of Conversion from MCI to AD.
in Medical Image Computing and Computer-Assisted Intervention MICCAI 2012, Springer Berlin Heidelberg, volume 7510, pp. 132-140, 2012. doi:10.1007/978-3-642-33415-3 17
- Nikhil Singh, P. Thomas Fletcher, J. Samuel Preston, Linh Ha, Richard King, J. Stephen Marron, Michael Wiener, and Sarang Joshi.
Multivariate Statistical Analysis of Deformation Momenta Relating Anatomical Shape to Neuropsychological Measures.
in Medical Image Computing and Computer-Assisted Intervention MICCAI 2010 volume 6363, pp. 529-537, 2010. doi:10.1007/978-3-642-15711-0_66
- Sourav Kole, Nikhil Singh, and Richard King.
Whole Brain Fractal Analysis of the Cerebral Cortex across the Adult Lifespan.
Neurology 2012; 78 (Meeting Abstracts 1):P03.104 doi:10.1212/WNL.78.1_MeetingAbstracts.P03.104