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Pradeep K Ravikumar

22 accepted papers

2020

On Completeness-aware Concept-Based Explanations in Deep Neural Networks

NeurIPS 2020poster

Human explanations of high-level decisions are often expressed in terms of key concepts the decisions are based on. In this paper, we study such concept-based explainability for Deep Neural Networks (DNNs). First, we define the notion of \emph{completeness}, which quantifies how sufficient a particu…

2020

On Learning Ising Models under Huber's Contamination Model

NeurIPS 2020poster

We study the problem of learning Ising models in a setting where some of the samples from the underlying distribution can be arbitrarily corrupted. In such a setup, we aim to design statistically optimal estimators in a high-dimensional scaling in which the number of nodes p, the number of edges k…

Cited by 23SourcePDFScholar
2019

Game Design for Eliciting Distinguishable Behavior

NeurIPS 2019poster

The ability to inferring latent psychological traits from human behavior is key to developing personalized human-interacting machine learning systems. Approaches to infer such traits range from surveys to manually-constructed experiments and games. However, these traditional games are limited becaus…

Cited by 2SourcePDFScholar
2019

On the (In)fidelity and Sensitivity of Explanations

NeurIPS 2019poster

We consider objective evaluation measures of saliency explanations for complex black-box machine learning models. We propose simple robust variants of two notions that have been considered in recent literature: (in)fidelity, and sensitivity. We analyze optimal explanations with respect to both these…

2019

Optimal Analysis of Subset-Selection Based L_p Low-Rank Approximation

NeurIPS 2019poster

We show that for the problem of $\ell_p$ rank-$k$ approximation of any given matrix over $R^{n\times m}$ and $C^{n\times m}$, the algorithm of column subset selection enjoys approximation ratio $(k+1)^{1/p}$ for $1\le p\le 2$ and $(k+1)^{1-1/p}$ for $p\ge 2$. This improves upon the previous $O(k+1)$…

Cited by 21SourcePDFScholar
2018

DAGs with NO TEARS: Continuous Optimization for Structure Learning

NeurIPS 2018spotlight

Estimating the structure of directed acyclic graphs (DAGs, also known as Bayesian networks) is a challenging problem since the search space of DAGs is combinatorial and scales superexponentially with the number of nodes. Existing approaches rely on various local heuristics for enforcing the acyclici…

2018

MixLasso: Generalized Mixed Regression via Convex Atomic-Norm Regularization

NeurIPS 2018poster

We consider a generalization of mixed regression where the response is an additive combination of several mixture components. Standard mixed regression is a special case where each response is generated from exactly one component. Typical approaches to the mixture regression problem employ local sea…

Cited by 3SourcePDFScholar
2018

Representer Point Selection for Explaining Deep Neural Networks

NeurIPS 2018poster

We propose to explain the predictions of a deep neural network, by pointing to the set of what we call representer points in the training set, for a given test point prediction. Specifically, we show that we can decompose the pre-activation prediction of a neural network into a linear combination of…

2018

The Sample Complexity of Semi-Supervised Learning with Nonparametric Mixture Models

NeurIPS 2018poster

We study the sample complexity of semi-supervised learning (SSL) and introduce new assumptions based on the mismatch between a mixture model learned from unlabeled data and the true mixture model induced by the (unknown) class conditional distributions. Under these assumptions, we establish an $\Ome…

Cited by 5SourcePDFScholar
2017

On Separability of Loss Functions, and Revisiting Discriminative Vs Generative Models

NeurIPS 2017spotlight

We revisit the classical analysis of generative vs discriminative models for general exponential families, and high-dimensional settings. Towards this, we develop novel technical machinery, including a notion of separability of general loss functions, which allow us to provide a general framework to…

Cited by 7SourcePDFScholar
2017

The Expxorcist: Nonparametric Graphical Models Via Conditional Exponential Densities

NeurIPS 2017poster

Non-parametric multivariate density estimation faces strong statistical and computational bottlenecks, and the more practical approaches impose near-parametric assumptions on the form of the density functions. In this paper, we leverage recent developments to propose a class of non-parametric models…

Cited by 20SourcePDFScholar
2016

Dual Decomposed Learning with Factorwise Oracle for Structural SVM of Large Output Domain

NeurIPS 2016poster

Many applications of machine learning involve structured output with large domain, where learning of structured predictor is prohibitive due to repetitive calls to expensive inference oracle. In this work, we show that, by decomposing training of Structural Support Vector Machine (SVM) into a series…

Cited by 10SourcePDFScholar
2015

Beyond Sub-Gaussian Measurements: High-Dimensional Structured Estimation with Sub-Exponential Designs

NeurIPS 2015poster

We consider the problem of high-dimensional structured estimation with norm-regularized estimators, such as Lasso, when the design matrix and noise are drawn from sub-exponential distributions.Existing results only consider sub-Gaussian designs and noise, and both the sample complexity and non-asymp…

Cited by 40SourcePDFScholar
2015

Closed-form Estimators for High-dimensional Generalized Linear Models

NeurIPS 2015spotlight

We propose a class of closed-form estimators for GLMs under high-dimensional sampling regimes. Our class of estimators is based on deriving closed-form variants of the vanilla unregularized MLE but which are (a) well-defined even under high-dimensional settings, and (b) available in closed-form. We…

Cited by 13SourcePDFScholar
2015

Collaborative Filtering with Graph Information: Consistency and Scalable Methods

NeurIPS 2015spotlight

Low rank matrix completion plays a fundamental role in collaborative filtering applications, the key idea being that the variables lie in a smaller subspace than the ambient space. Often, additional information about the variables is known, and it is reasonable to assume that incorporating this info…

2015

Consistent Multilabel Classification

NeurIPS 2015poster

Multilabel classification is rapidly developing as an important aspect of modern predictive modeling, motivating study of its theoretical aspects. To this end, we propose a framework for constructing and analyzing multilabel classification metrics which reveals novel results on a parametric form for…

Cited by 129SourcePDFScholar
2015

Fast Classification Rates for High-dimensional Gaussian Generative Models

NeurIPS 2015poster

We consider the problem of binary classification when the covariates conditioned on the each of the response values follow multivariate Gaussian distributions. We focus on the setting where the covariance matrices for the two conditional distributions are the same. The corresponding generative model…

Cited by 12SourcePDFScholar
2015

Fixed-Length Poisson MRF: Adding Dependencies to the Multinomial

NeurIPS 2015poster

We propose a novel distribution that generalizes the Multinomial distribution to enable dependencies between dimensions. Our novel distribution is based on the parametric form of the Poisson MRF model [Yang et al., 2012] but is fundamentally different because of the domain restriction to a fixed-len…

Cited by 8SourcePDFScholar
2015

Sparse Linear Programming via Primal and Dual Augmented Coordinate Descent

NeurIPS 2015poster

Over the past decades, Linear Programming (LP) has been widely used in different areas and considered as one of the mature technologies in numerical optimization. However, the complexity offered by state-of-the-art algorithms (i.e. interior-point method and primal, dual simplex methods) is still uns…

Cited by 40SourcePDFScholar