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Takafumi Kanamori

6 accepted papers

2022

Mode estimation on matrix manifolds: Convergence and robustness

AISTATS 2022poster

Data on matrix manifolds are ubiquitous on a wide range of research fields. The key issue is estimation of the modes (i.e., maxima) of the probability density function underlying the data. For instance, local modes (i.e., local maxima) can be used for clustering, while the global mode (i.e., the glo…

Cited by 1SourcePDFScholar
2020

A Unified Statistically Efficient Estimation Framework for Unnormalized Models

AISTATS 2020poster

The parameter estimation of unnormalized models is a challenging problem. The maximum likelihood estimation (MLE) is computationally infeasible for these models since normalizing constants are not explicitly calculated. Although some consistent estimators have been proposed earlier, the problem of s…

Cited by 18SourcePDFScholar
2020

Robust modal regression with direct gradient approximation of modal regression risk

UAI 2020poster

Modal regression is aimed at estimating the global mode (i.e., global maximum) of the conditional density function of the output variable given input variables, and has led to regression methods robust against a wide-range of noises. A typical approach for modal regression takes a two-step approach…

Cited by 4SourcePDFScholar
2019

Fisher Efficient Inference of Intractable Models

NeurIPS 2019poster

Maximum Likelihood Estimators (MLE) has many good properties. For example, the asymptotic variance of MLE solution attains equality of the asymptotic Cram{\'e}r-Rao lower bound (efficiency bound), which is the minimum possible variance for an unbiased estimator. However, obtaining such MLE solution…

2017

Estimating Density Ridges by Direct Estimation of Density-Derivative-Ratios

AISTATS 2017poster

Estimation of \emphdensity ridges has been gathering a great deal of attention since it enables us to reveal lower-dimensional structures hidden in data. Recently, \emphsubspace constrained mean shift (SCMS) was proposed as a practical algorithm for density ridge estimation. A key technical ingredie…

Cited by 8SourcePDFScholar
2015

Empirical Localization of Homogeneous Divergences on Discrete Sample Spaces

NeurIPS 2015spotlight

In this paper, we propose a novel parameter estimator for probabilistic models on discrete space. The proposed estimator is derived from minimization of homogeneous divergence and can be constructed without calculation of the normalization constant, which is frequently infeasible for models in the d…

Cited by 11SourcePDFScholar