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Vikas Singh

69 accepted papers

2026

MnemoDyn: Learning Resting State Dynamics from $40$K FMRI sequences

ICLR 2026poster

We present a dynamical-systems based model for resting-state functional magnetic resonance imaging (rs-fMRI), trained on a dataset of roughly $40$K rs-fMRI sequences covering a wide variety of public and available-by-permission datasets. While most existing proposals use transformer backbones, we u…

Cited by 0SourceScholar
2026

Tree-Structured Orthonormal Decomposition of the Aitchison Simplex

ICML 2026poster

Compositional data---vectors encoding relative proportions---arise across scientific domains, including ecology, geochemistry, and genomics. The features in these data often come with known hierarchical structure (e.g., taxonomies, phylogenies, ontologies), yet existing methods either ignore this st…

Cited by 0SourceScholar
2025

FoGE: Fock Space inspired encoding for graph prompting

NeurIPS 2025poster

Recent results show that modern Large Language Models (LLM) are indeed capable of understanding and answering questions about structured data such as graphs. This new paradigm can lead to solutions that require less supervision while, at the same time, providing a model that can generalize and answe…

Cited by 0SourcecodeScholar
2025

SimpleTM: A Simple Baseline for Multivariate Time Series Forecasting

ICLR 2025poster

The versatility of large Transformer-based models has led to many efforts focused on adaptations to other modalities, including time-series data. For instance, one could start from a pre-trained checkpoint of a large language model and attach adapters to recast the new modality (e.g., time-series)…

Cited by 1SourcePDFScholar
2024

FrameQuant: Flexible Low-Bit Quantization for Transformers

ICML 2024poster

Transformers are the backbone of powerful foundation models for many Vision and Natural Language Processing tasks. But their compute and memory/storage footprint is large, and so, serving such models is expensive often requiring high-end hardware. To mitigate this difficulty, Post-Training Quantizat…

2024

IM-Unpack: Training and Inference with Arbitrarily Low Precision Integers

ICML 2024poster

GEneral Matrix Multiply (GEMM) is a central operation in deep learning and corresponds to a large chunk of the compute footprint. Therefore, improving its efficiency is an active topic of research. A popular strategy is the use of low bit-width integers to approximate the original matrix entries. Th…

2024

Implicit Representations via Operator Learning

ICML 2024poster

The idea of representing a signal as the weights of a neural network, called *Implicit Neural Representations* (INRs), has led to exciting implications for compression, view synthesis and 3D volumetric data understanding. One problem in this setting pertains to the use of INRs for downstream process…

2024

Pooling Image Datasets with Multiple Covariate Shift and Imbalance

ICLR 2024poster

Small sample sizes are common in many disciplines, which necessitates pooling roughly similar datasets across multiple sites/institutions to study weak but relevant associations between images and disease incidence. Such data often manifest shifts and imbalances in covariates (secondary non-ima…

Cited by 3SourcePDFScholar
2024

Understanding Multi-compositional learning in Vision and Language models via Category Theory

ECCV 2024poster

"Pre-trained large language models (and multi-modal models) offer excellent performance across a wide range of tasks. Despite their effectiveness, we have limited knowledge of their internal knowledge representation. To get started, we use the classic problem of Compositional Zero-Shot Learning (CZS…

2023

Controlled Differential Equations on Long Sequences via Non-standard Wavelets

ICML 2023poster

Neural Controlled Differential equations (NCDE) are a powerful mechanism to model the dynamics in temporal sequences, e.g., applications involving physiological measures, where apart from the initial condition, the dynamics also depend on subsequent measures or even a different "control" sequence. B…

Cited by 2SourcePDFScholar
2023

Efficient Discrete Multi Marginal Optimal Transport Regularization

ICLR 2023top-25%

Optimal transport has emerged as a powerful tool for a variety of problems in machine learning, and it is frequently used to enforce distributional constraints. In this context, existing methods often use either a Wasserstein metric, or else they apply concurrent barycenter approaches when more than…

Cited by 6SourcePDFScholar
2023

LookupFFN: Making Transformers Compute-lite for CPU inference

ICML 2023poster

While GPU clusters are the de facto choice for training large deep neural network (DNN) models today, several reasons including ease of workflow, security and cost have led to efforts investigating whether CPUs may be viable for inference in routine use in many sectors of the industry. But the imbal…

2023

VCC: Scaling Transformers to 128K Tokens or More by Prioritizing Important Tokens

NeurIPS 2023poster

Transformers are central in modern natural language processing and computer vision applications. Despite recent works devoted to reducing the quadratic cost of such models with respect to sequence length, dealing with ultra long sequences (e.g., $>$16K tokens) remains challenging. Applications such…

2022

Deep Unlearning via Randomized Conditionally Independent Hessians

CVPR 2022poster

Recent legislation has led to interest in machine unlearning, i.e., removing specific training samples from a predictive model as if they never existed in the training dataset. Unlearning may also be required due to corrupted/adversarial data or simply a user's updated privacy requirement. For model…

Cited by 100PDFcodeScholar
2022

Equivariance Allows Handling Multiple Nuisance Variables When Analyzing Pooled Neuroimaging Datasets

CVPR 2022poster

Pooling multiple neuroimaging datasets across institutions often enables significant improvements in statistical power when evaluating associations (e.g., between risk factors and disease outcomes) that would otherwise be too weak to detect. When there is only a single source of variability (e.g.…

Cited by 5PDFcodeScholar
2022

Forward Operator Estimation in Generative Models with Kernel Transfer Operators

ICML 2022spotlight

Generative models which use explicit density modeling (e.g., variational autoencoders, flow-based generative models) involve finding a mapping from a known distribution, e.g. Gaussian, to the unknown input distribution. This often requires searching over a class of non-linear functions (e.g., repres…

2022

Multi Resolution Analysis (MRA) for Approximate Self-Attention

ICML 2022spotlight

Transformers have emerged as a preferred model for many tasks in natural langugage processing and vision. Recent efforts on training and deploying Transformers more efficiently have identified many strategies to approximate the self-attention matrix, a key module in a Transformer architecture. Effec…

2022

On the Versatile Uses of Partial Distance Correlation in Deep Learning

ECCV 2022poster

"Comparing the functional behavior of neural network models, whether it is a single network over time or two (or more networks) during or post-training, is an essential step in understanding what they are learning (and what they are not), and for identifying strategies for regularization or efficien…

2022

Understanding Uncertainty Maps in Vision With Statistical Testing

CVPR 2022poster

Quantitative descriptions of confidence intervals and uncertainties of the predictions of a model are needed in many applications in vision and machine learning. Mechanisms that enable this for deep neural network (DNN) models are slowly becoming available, and occasionally, being integrated within…

Cited by 3PDFcodeScholar
2021

A variational approximation for analyzing the dynamics of panel data

UAI 2021poster

Panel data involving longitudinal measurements of the same set of participants or entities taken over multiple time points is common in studies to understand early childhood development and disease modeling. Deep hybrid models that marry the predictive power of neural networks with physical simulato…

2021

An Online Riemannian PCA for Stochastic Canonical Correlation Analysis

NeurIPS 2021poster

We present an efficient stochastic algorithm (RSG+) for canonical correlation analysis (CCA) using a reparametrization of the projection matrices. We show how this reparametrization (into structured matrices), simple in hindsight, directly presents an opportunity to repurpose/adjust mature technique…

Cited by 16SourcePDFScholar
2021

Connecting What To Say With Where To Look by Modeling Human Attention Traces

CVPR 2021poster

We introduce a unified framework to jointly model images, text, and human attention traces. Our work is built on top of the recent Localized Narratives annotation framework, where each word of a given caption is paired with a mouse trace segment. We propose two novel tasks: (1) predict a trace given…

Cited by 32PDFcodeScholar
2021

Differentiable Optimization of Generalized Nondecomposable Functions using Linear Programs

NeurIPS 2021poster

We propose a framework which makes it feasible to directly train deep neural networks with respect to popular families of task-specific non-decomposable performance measures such as AUC, multi-class AUC, $F$-measure and others. A common feature of the optimization model that emerges from these tasks…

Cited by 1SourcePDFScholar
2021

Flow-based Generative Models for Learning Manifold to Manifold Mappings

AAAI 2021technical

Many measurements or observations in computer vision and machine learning manifest as non-Euclidean data. While recent proposals (like spherical CNN) have extended a number of deep neural network architectures to manifold-valued data, and this has often provided strong improvements in performance, t…

2021

Graph reparameterizations for enabling 1000+ Monte Carlo iterations in Bayesian deep neural networks

UAI 2021poster

Uncertainty estimation in deep models is essential in many real-world applications and has benefited from developments over the last several years. Recent evidence suggests that existing solutions dependent on simple Gaussian formulations may not be sufficient. However, moving to other distributions…

2021

Learning Invariant Representations using Inverse Contrastive Loss

AAAI 2021technical

Learning invariant representations is a critical first step in a number of machine learning tasks. A common approach is given by the so-called information bottleneck principle in which an application dependent function of mutual information is carefully chosen and optimized. Unfortunately, in practi…

2021

MobileDets: Searching for Object Detection Architectures for Mobile Accelerators

CVPR 2021poster

Inverted bottleneck layers, which are built upon depthwise convolutions, have been the predominant building blocks in state-of-the-art object detection models on mobile devices. In this work, we investigate the optimality of this design pattern over a broad range of mobile accelerators by revisiting…

Cited by 189PDFcodeScholar
2021

Neural TMDlayer: Modeling Instantaneous Flow of Features via SDE Generators

ICCV 2021poster

We study how stochastic differential equation (SDE) based ideas can inspire new modifications to existing algorithms for a set of problems in computer vision. Loosely speaking, our formulation is related to both explicit and implicit strategies for data augmentation and group equivariance, but is de…

Cited by 1PDFcodeScholar
2021

Nyströmformer: A Nyström-based Algorithm for Approximating Self-Attention

AAAI 2021technical

Transformers have emerged as a powerful tool for a broad range of natural language processing tasks. A key component that drives the impressive performance of Transformers is the self-attention mechanism that encodes the influence or dependence of other tokens on each specific token. While beneficia…

2021

Physarum Powered Differentiable Linear Programming Layers and Applications

AAAI 2021technical

Consider a learning algorithm, which involves an internal call to an optimization routine such as a generalized eigenvalue problem, a cone programming problem or even sorting. Integrating such a method as layers within a trainable deep network in a numerically stable way is not simple – for instance…

2021

You Only Sample (Almost) Once: Linear Cost Self-Attention Via Bernoulli Sampling

ICML 2021spotlight

Transformer-based models are widely used in natural language processing (NLP). Central to the transformer model is the self-attention mechanism, which captures the interactions of token pairs in the input sequences and depends quadratically on the sequence length. Training such models on longer sequ…

2020

FairALM: Augmented Lagrangian Method for Training Fair Models with Little Regret

ECCV 2020poster

Algorithmic decision making based on computer vision and machine learning technologies continue to permeate our lives. But issues related to biases of these models and the extent to which they treat certain segments of the population unfairly, have led to concern in the general public. It is now acc…

2020

Generating Accurate Pseudo-Labels in Semi-Supervised Learning and Avoiding Overconfident Predictions via Hermite Polynomial Activations

CVPR 2020poster

Rectified Linear Units (ReLUs) are among the most widely used activation function in a broad variety of tasks in vision. Recent theoretical results suggest that despite their excellent practical performance, in various cases, a substitution with basis expansions (e.g., polynomials) can yield signifi…

Cited by 42PDFcodeScholar
2019

Adaptive Activation Thresholding: Dynamic Routing Type Behavior for Interpretability in Convolutional Neural Networks

ICCV 2019poster

There is a growing interest in strategies that can help us understand or interpret neural networks -- that is, not merely provide a prediction, but also offer additional context explaining why and how. While many current methods offer tools to perform this analysis for a given (trained) network post…

Cited by 17PDFScholar
2019

Conditional Recurrent Flow: Conditional Generation of Longitudinal Samples With Applications to Neuroimaging

ICCV 2019accepted

We develop a conditional generative model for longitudinal image datasets based on sequential invertible neural networks. Longitudinal image acquisitions are common in various scientific and biomedical studies where often each image sequence sample may also come together with various secondary (fixe…

Cited by 13SourcePDFScholar
2019

DUAL-GLOW: Conditional Flow-Based Generative Model for Modality Transfer

ICCV 2019accepted

Positron emission tomography (PET) imaging is an imaging modality for diagnosing a number of neurological diseases. In contrast to Magnetic Resonance Imaging (MRI), PET is costly and involves injecting a radioactive substance into the patient. Motivated by developments in modality transfer in vision…

2019

Dilated Convolutional Neural Networks for Sequential Manifold-Valued Data

ICCV 2019accepted

Efforts are underway to study ways via which the power of deep neural networks can be extended to non-standard data types such as structured data (e.g., graphs) or manifold-valued data (e.g., unit vectors or special matrices). Often, sizable empirical improvements are possible when the geometry of s…

2019

Mixed Effects Neural Networks (MeNets) With Applications to Gaze Estimation

CVPR 2019poster

There is much interest in computer vision to utilize commodity hardware for gaze estimation. A number of papers have shown that algorithms based on deep convolutional architectures are approaching accuracies where streaming data from mass-market devices can offer good gaze tracking performance, alth…

Cited by 126PDFcodeScholar
2019

Resource Constrained Neural Network Architecture Search: Will a Submodularity Assumption Help?

ICCV 2019poster

The design of neural network architectures is frequently either based on human expertise using trial/error and empirical feedback or tackled via large scale reinforcement learning strategies performed over distinct discrete architecture choices. In the latter case, the optimization is often non-diff…

Cited by 45PDFcodeScholar
2019

Sampling-free Uncertainty Estimation in Gated Recurrent Units with Applications to Normative Modeling in Neuroimaging

UAI 2019poster

There has recently been a concerted effort to derive mechanisms in vision and machine learning systems to offer uncertainty estimates of the predictions they make. Clearly, there are enormous benefits to a system that is not only accurate but also has a sense for when it is not. Existing proposals c…

Cited by 8SourcePDFScholar
2019

Scaling Recurrent Models via Orthogonal Approximations in Tensor Trains

ICCV 2019poster

Modern deep networks have proven to be very effective for analyzing real world images. However, their application in medical imaging is still in its early stages, primarily due to the large size of three-dimensional images, requiring enormous convolutional or fully connected layers - if we treat an…

Cited by 4PDFcodeScholar
2018

A Biresolution Spectral Framework for Product Quantization

CVPR 2018poster

Product quantization (PQ) (and its variants) has been effec- tively used to encode high-dimensional data into compact codes for many problems in vision. In principle, PQ decomposes the given data into a number of lower-dimensional subspaces where the quantization proceeds independently for each subs…

Cited by 3SourcePDFScholar
2018

A Statistical Recurrent Model on the Manifold of Symmetric Positive Definite Matrices

NeurIPS 2018poster

In a number of disciplines, the data (e.g., graphs, manifolds) to be analyzed are non-Euclidean in nature. Geometric deep learning corresponds to techniques that generalize deep neural network models to such non-Euclidean spaces. Several recent papers have shown how convolutional neural networks (C…

2018

Efficient Relative Attribute Learning using Graph Neural Networks

ECCV 2018poster

A sizable body of work on relative attributes provides compelling evidence that relating pairs of images along a continuum of strength pertaining to a visual attribute yields significant improvements in a wide variety of tasks in vision. In this paper, we show how emerging ideas in graph neural netw…

2018

Tensorize, Factorize and Regularize: Robust Visual Relationship Learning

CVPR 2018poster

Visual relationships provide higher-level information of objects and their relations in an image – this enables a semantic understanding of the scene and helps downstream applications. Given a set of localized objects in some training data, visual relationship detection seeks to detect the most like…

Cited by 74SourcePDFScholar
2017

A Geometric Framework for Statistical Analysis of Trajectories With Distinct Temporal Spans

ICCV 2017poster

Analyzing data representing multifarious trajectories is central to the many fields in Science and Engineering; for example, trajectories representing a tennis serve, a gymnast's parallel bar routine, progression/remission of disease and so on. We present a novel geometric algorithm for performing s…

Cited by 8PDFScholar
2017

Filter Flow Made Practical: Massively Parallel and Lock-Free

CVPR 2017poster

This paper is inspired by a relatively recent work of Seitz and Baker which introduced the so-called Filter Flow model. Filter flow finds the transformation relating a pair of (or multiple) images by identifying a large set of local linear filters; imposing additional constraints on certain structur…

Cited by 6PDFcodeScholar
2017

Online Graph Completion: Multivariate Signal Recovery in Computer Vision

CVPR 2017poster

The adoption of "human-in-the-loop" paradigms in computer vision and machine learning is leading to various applications where the actual data acquisition (e.g., human supervision) and the underlying inference algorithms are closely interwined. While classical work in active learning provides effect…

Cited by 7PDFScholar
2017

Riemannian Nonlinear Mixed Effects Models: Analyzing Longitudinal Deformations in Neuroimaging

CVPR 2017poster

Statistical machine learning models that operate on manifold-valued data are being extensively studied in vision, motivated by applications in activity recognition, feature tracking and medical imaging. While non-parametric methods have been relatively well studied in the literature, efficient formu…

Cited by 34PDFScholar
2017

The Incremental Multiresolution Matrix Factorization Algorithm

CVPR 2017poster

Multiresolution analysis and matrix factorization are foundational tools in computer vision. In this work, we study the interface between these two distinct topics and obtain techniques to uncover hierarchical block structure in symmetric matrices -- an important aspect in the success of many vision…

Cited by 14PDFScholar
2017

When can Multi-Site Datasets be Pooled for Regression? Hypothesis Tests, $\ell_2$-consistency and Neuroscience Applications

ICML 2017poster

Many studies in biomedical and health sciences involve small sample sizes due to logistic or financial constraints. Often, identifying weak (but scientifically interesting) associations between a set of predictors and a response necessitates pooling datasets from multiple diverse labs or groups. Whi…

2016

Coupled Harmonic Bases for Longitudinal Characterization of Brain Networks

CVPR 2016poster

There is a great deal of interest in using large scale brain imaging studies to understand how brain connectivity evolves over time for an individual and how it varies over different levels/quantiles of cognitive function. To do so, one typically performs so-called tractography procedures on diffusi…

Cited by 9PDFScholar
2016

Experimental Design on a Budget for Sparse Linear Models and Applications

ICML 2016poster

Budget constrained optimal design of experiments is a classical problem in statistics. Although the optimal design literature is very mature, few efficient strategies are available when these design problems appear in the context of sparse linear models commonly encountered in high dimensional machi…

Cited by 20SourcePDFScholar
2016

Hypothesis Testing in Unsupervised Domain Adaptation with Applications in Alzheimer's Disease

NeurIPS 2016poster

Consider samples from two different data sources $\{\mathbf{x_s^i}\} \sim P_{\rm source}$ and $\{\mathbf{x_t^i}\} \sim P_{\rm target}$. We only observe their transformed versions $h(\mathbf{x_s^i})$ and $g(\mathbf{x_t^i})$, for some known function class $h(\cdot)$ and $g(\cdot)$. Our goal is to perf…

Cited by 20SourcePDFScholar
2016

Latent Variable Graphical Model Selection Using Harmonic Analysis: Applications to the Human Connectome Project (HCP)

CVPR 2016spotlight

A major goal of imaging studies such as the (ongoing) Human Connectome Project (HCP) is to characterize the structural network map of the human brain and identify its associations with covariates such as genotype, risk factors, and so on that correspond to an individual. But the set of image derived…

Cited by 8PDFScholar
2015

A Projection Free Method for Generalized Eigenvalue Problem With a Nonsmooth Regularizer

ICCV 2015poster

Eigenvalue problems are ubiquitous in computer vision, covering a very broad spectrum of applications ranging from estimation problems in multi-view geometry to image segmentation. Few other linear algebra problems have a more mature set of numerical routines available and many computer vision libra…

Cited by 13PDFScholar
2015

Gaze-Enabled Egocentric Video Summarization via Constrained Submodular Maximization

CVPR 2015poster

With the proliferation of wearable cameras, the number of videos of users documenting their personal lives using such devices is rapidly increasing. Since such videos may span hours, there is an important need for mechanisms that represent the information content in a compact form (i.e., shorter…

Cited by 207SourcePDFScholar
2015

Interpolation on the Manifold of K Component GMMs

ICCV 2015poster

Probability density functions (PDFs) are fundamental "objects" in mathematics with numerous applications in computer vision, machine learning and medical imaging. The feasibility of basic operations such as computing the distance between two PDFs and estimating a mean of a set of PDFs is a direct fu…

Cited by 6PDFScholar
2015

On Statistical Analysis of Neuroimages With Imperfect Registration

ICCV 2015poster

A variety of studies in neuroscience/neuroimaging seek to perform statistical inference on the acquired brain image scans for diagnosis as well as understanding the pathological manifestation of diseases. To do so, an important first step is to register (or co-register) all of the image data into a…

Cited by 4PDFScholar
2015

Statistical Inference Models for Image Datasets With Systematic Variations

CVPR 2015poster

Statistical analysis of longitudinal or cross sectionalbrain imaging data to identify effects of neurodegenerative diseases is a fundamental task in various studies in neuroscience. However, when there are systematic variations in the images due to parameters changes such as changes in the scanner p…

Cited by 9SourcePDFScholar