Yash Sharma

I am a PhD candidate at the International Max Planck Research School for Intelligent Systems, working in the lab of Matthias Bethge under the supervision of Wieland Brendel. I've completed my Bachelors and Masters from the Cooper Union, and have spent time at Flagship Pioneering, Google Brain, Meta AI, Amazon, Borealis AI and IBM Research.

My research has focused on adversarial robustness, representation learning, and compositional generalization.

If you would like to chat regarding research directions or career/school decisions, feel free to book a time.

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Research
No "Zero-Shot" Without Exponential Data: Pretraining Concept Frequency Determines Multimodal Model Performance
Vishaal Udandarao*, Ameya Prabhu*, Adhiraj Ghosh, Yash Sharma, Philip H.S. Torr, Adel Bibi, Samuel Albanie, Matthias Bethge (*equal contribution)
arXiv:2404.04125, 2024
paper / code / benchmark

Increasing training data frequency of concepts exponentially yields linear improvements in downstream "zero-shot" performance, thus constituting sample inefficient log-linear scaling.

Attribute Diversity Determines the Systematicity Gap in VQA
Ian Berlot-Attwell, A. Michael Carrell, Kumar Krishna Agrawal, Yash Sharma†, Naomi Saphra† (†senior author)
arXiv:2311.08695, 2023
paper

Increasing training data diversity of attributes in unseen combinations reduces the systematicity gap in visual question answering.

On Transfer of Adversarial Robustness from Pre-training to Downstream Tasks
Laura Fee Nern, Harsh Raj, Maurice Georgi, Yash Sharma† (†senior author)
NeurIPS, 2023
KDD AdvML Workshop, 2022
paper / code

Bounding the robustness of a predictor on downstream tasks by the robustness of the representation that underlies it.

Provably Learning Object-Centric Representations
Jack Brady*, Roland S. Zimmermann*, Yash Sharma, Bernhard Schölkopf, Julius von Kügelgen, Wieland Brendel (*equal contribution)
ICML, 2023
paper / code

Identifying ground-truth object representations, even in the presence of dependencies between objects, by learning an invertible and compositional inference model.

Jacobian-based Causal Discovery with Nonlinear ICA
Patrik Reizinger, Yash Sharma, Matthias Bethge, Bernhard Schölkopf, Ferenc Huszár, Wieland Brendel
TMLR, 2023

UAI CRL Workshop, 2022
paper / code

Uncovering causal relationships from observational data by relying on the Jacobian of the function inferring the underlying sources from the observed variables.

Pixel-level Correspondence for Self-Supervised Learning from Video
Yash Sharma, Yi Zhu, Chris Russell, Thomas Brox
ICML Pre-training Workshop, 2022
paper

Match local features at different points in time by tracking points with optical flow.

Disentanglement via Mechanism Sparsity Regularization: A New Principle for Nonlinear ICA
Sébastien Lachapelle, Pau Rodríguez López, Yash Sharma, Katie Everett, Rémi Le Priol Alexandre Lacoste Simon Lacoste-Julien
CLeaR, 2022
paper / code

Disentanglement, allowing for dependence between sequences of transitions, by identifying both the factors of variation and the sparse causal graphical model that relates them.

Unsupervised Learning of Compositional Energy Concepts
Yilun Du, Shuang Li, Yash Sharma, Josh Tenenbaum, Igor Mordatch
NeurIPS, 2021
paper / website / code

Enabled flexible compositions of discovered concepts, across modalities and datasets, by formulating sample generation as an optimization process on underlying energy functions.

Self-Supervised Learning with Data Augmentations Provably Isolates Content from Style
Julius von Kügelgen*, Yash Sharma*, Luigi Gresele*, Wieland Brendel, Bernhard Schölkopf, Michel Besserve, Francesco Locatello (*equal contribution)
NeurIPS, 2021
ICML SSL Workshop, 2021
paper / code / talk

We show that contrastive learning isolates the features data augmentations leave invariant, providing a proof of identifiability and empirical results on a novel visually complex benchmark with causal dependencies.

Contrastive Learning Inverts the Data Generating Process
Roland S. Zimmermann*, Yash Sharma*, Steffen Schneider*, Matthias Bethge, Wieland Brendel (*equal contribution)
ICML, 2021
NeurIPS SSL Workshop, 2020
paper / website / code

We show that contrastive learning can uncover the underlying factors of variation, with proofs and empirical success on a novel visually complex dataset.

Benchmarking Unsupervised Object Representations for Video Sequences
Marissa A. Weis, Kashyap Chitta, Yash Sharma, Wieland Brendel, Matthias Bethge, Andreas Geiger, Alexander Ecker
JMLR, 2021
paper / code / talk

Provide a video benchmark as well as an extension of a static method for unsupervised learning of object-centric representations for analysis.

Towards Nonlinear Disentanglement in Natural Data with Temporal Sparse Coding
David Klindt*, Lukas Schott*, Yash Sharma*, Ivan Ustyuzhaninov, Wieland Brendel, Matthias Bethge, Dylan Paiton (*equal contribution)
ICLR, 2021   (Oral; 53/2997 submissions)
paper / code / oral / talk

We show that accounting for the temporally sparse nature of natural transitions leads to a proof of identifiability and reliable learning of disentangled representations on several established benchmark datasets, as well as contributed datasets with natural dynamics.

S2RMs: Spatially Structured Recurrent Modules
Nasim Rahaman, Anirudh Goyal, Muhammad Waleed Gondal, Manuel Wüthrich, Stefan Bauer, Yash Sharma, Yoshua Bengio, Bernhard Schölkopf
ICLR, 2021
ICML BIG Workshop, 2020
paper / code

Contribute a model class that is well suited for modeling the dynamics of systems that only offer local views into their state, along with corresponding spatial locations of those views.

MMA Training: Direct Input Space Margin Maximization through Adversarial Training
Gavin Weiguang Ding, Yash Sharma, Kry Yik Chau Lui, Ruitong Huang
ICLR, 2020
ICLR SafeML Workshop, 2019
paper / code

Directly maximizing input space margin removes the requirement of specifying a fixed distortion bound for improving adversarial robustness.

On the Effectiveness of Low Frequency Perturbations
Yash Sharma, Gavin Weiguang Ding, Marcus Brubaker
IJCAI, 2019
paper / blog

Defended ImageNet models based on adversarial training are roughly as vulnerable to low frequency perturbations as undefended models.

Are Generative Classifiers More Robust to Adversarial Attacks?
Yingzhen Li, John Bradshaw, Yash Sharma
ICML, 2019
ICML TADGM Workshop, 2018
paper / code

Across factorization structures, provide evidence that generative classifiers are more robust to adversarial attacks than discriminative classifiers.

GenAttack: Practical Black-box Attacks with Gradient-Free Optimization
Moustafa Alzantot, Yash Sharma, Supriyo Chakraborty, Huan Zhang, Cho-Jui Hsieh, Mani Srivastava
GECCO, 2019
paper / code

Evolutionary strategies can be used to synthesize adversarial examples in the black-box setting with orders of magnitude fewer queries than previous approaches.

CAAD 2018: Generating Transferable Adversarial Examples
Yash Sharma, Tien-Dung Le, Moustafa Alzantot
arXiv:1810.01268, 2018
paper / code / press

Placed 1st, 1st, and 3rd in the targeted attack, non-targeted attack, and defense competitions, respectively, winning the competition overall. Prize: $38,000.

Generating Natural Language Adversarial Examples
Moustafa Alzantot*, Yash Sharma*, Ahmed Elgohary, Bo-Jhang Ho, Mani Srivastava, Kai-Wei Chang (*equal contribution)
EMNLP, 2018
NeurIPS SecML Workshop (Encore Track), 2018
paper / code

Generate adversarial examples that fool well-trained sentiment analysis and textual entailment models in the black-box setting while preserving semantics and syntactics of the original.

Technical Report on the CleverHans v2.1.0 Adversarial Examples Library
Nicolas Papernot, Fartash Faghri, Nicholas Carlini, Ian Goodfellow, Reuben Feinman, Alexey Kurakin, Cihang Xie, Yash Sharma,...
arXiv:1610.00768, 2018
paper / code

Contributed to the CleverHans software library.

Gradient-based Adversarial Attacks to Deep Neural Networks in Limited Access Settings
Yash Sharma
Master's Thesis, 2018
paper / slides

Thesis Advisor: Sam Keene

Bypassing Feature Squeezing by Increasing Adversary Strength
Yash Sharma, Pin-Yu Chen
arXiv:1803.09868, 2018
paper

Can bypass the feature squeezing detection framework with adversarial examples of minimal visual distortion by simply evaluating with stronger attack configurations.

Attacking the Madry Defense Model with L1-based Adversarial Examples
Yash Sharma, Pin-Yu Chen
ICLR Workshop Track, 2018
paper

Models adversarially trained on the L_inf metric are vulnerable to L1-based adversarial examples of minimal visual distortion.

EAD: Elastic-Net Attacks to Deep Neural Networks via Adversarial Examples
Pin-Yu Chen*, Yash Sharma*, Huan Zhang, Jinfeng Yi, Cho-Jui Hsieh (*equal contribution)
AAAI, 2018 (Oral)
paper / code

Encouraging sparsity in the perturbation with L1 minimization leads to improved attack transferability and complements adversarial training.

ZOO: Zeroth Order Optimization based Black-box Attacks to Deep Neural Networks without Training Substitute Models
Pin-Yu Chen*, Huan Zhang*, Yash Sharma, Jinfeng Yi, Cho-Jui Hsieh (*equal contribution)
ACM CCS AISec, 2017 (Best Paper Award Finalist)
paper / code

Directly estimate the gradients of the target model for generating adversarial examples in the black-box setting, sparing the need for training substitute models and avoiding the loss in attack transferability.

Projects
Abstraction and Reasoning Challenge
Yuki Kubo, Anastasia Karpovich, Tien-Dung Le, Hieu Phung, Yash Sharma
Solving Unseen Reasoning Tasks, 2020
solution

Built set of functions based on implementing solutions for the provided tasks, searched for the correct composition for a given task at runtime. Served in mainly an advisory role.

Adversarial Attacks and Defences Competition
Yash Sharma, Moustafa Alzantot, Supriyo Chakraborty, Tianwei Xing, Sikai Yin, Mani Srivastava
NeurIPS Competition Track, 2017
code

Teamed with UCNesl to finish with one gold and two silver medals in the competition track.

Lane Keeping and Navigation Assist System
Yash Sharma, Vishnu Kaimal
Senior Project, 2017-2018
IEEE Student Paper, 2018
full report / writeup / poster / demo

Built an autonomous vehicle which can navigate through maps consisting of various road topologies.

Learning to Play Super Smash Bros. Melee with Delayed Actions
Yash Sharma, Eli Friedman
Deep Learning Final Project, 2017
report

Stabilized the training of competitive agents under human-level action delay through adding recurrence to the DQN architecture.

The Game of Set
Yash Sharma, Sahil Patel, Shalin Patel, Kevin Sheng
Software Engineering Final Project, 2017
code / slides

Developed a client-server application which allows users to play the game of SET against each other over the network.

Using Macroeconomic Forecasts to Improve Mean Reverting Trading Strategies
Yash Sharma
Business Economics Final Project, 2017
paper / code

Implemented a multiple pairs trading strategy on major currency pairs and improved the APR over the evaluation period by factoring in forecasts of a series of pertinent macroeconomic variables by optimizing the weights of the trading signals.

Unsupervised Pretraining
Yash Sharma, Sahil Patel
Deep Learning Midterm Project, 2017
code

Implemented the Split-Brain Autoencoder in TensorFlow and showed that the extracted features can help supervised learning when labeling is costly.

Asuisstant
Yash Sharma, Brenda So, Shalin Patel
CodeSuisse Hackathon (Winner), 2016
code

Built an android application which allows users to record notes about their meetings, write messages that will be displayed on a Twitter-like feed, and determine viability of initiatives regarding specific tickers through sentiment analysis run on written logs.

SSBY Architecture
Yash Sharma, Shalin Patel, Matt Cavallaro
Computer Architecture Final Project, 2016
code

Built an 8-bit single-cycle processor with a 4-byte cache for data memory capable of executing nested procedures, leaf procedures, signed addition, loops, and recursion.

Polldentify
Yash Sharma, Brenda So, Sahil Patel, Gordon Su
IBM Sparkathon, 2016
code / dataset

Traced the sources of pollution in the continental United States through compiling data from the EPA, NOAA, and Google Maps API, estimating the parameters of a gaussian dispersion model, and predicting pollutant concentration in the future with linear regression.


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