I am a CS PhD student at University of Washington jointly advised by Ali Farhadi and Sham Kakade. My broad research interests at the moment lie in the intersection of Machine Learning, Computer Vision and Robotics (Multimodal Perception, shh! it is a secret).
Before coming here, I spent two amazing years as a Research Fellow at Microsoft Research India with Manik Varma and Prateek Jain working on "The Extremes of Machine Learning". I have a Bachelors in CS with Honours and a Minor in EE from IIT Bombay where I had the pleasure of working with Soumen Chakrabarti on geometric embeddings for Entity Typing.
This paper introduces a new learning paradigm called eXtreme Regression (XR) whose objective is to accurately predict the numerical degrees of relevance of an extremely large number of labels to a data point. XR can provide elegant solutions to many large-scale ranking and recommendation applications including Dynamic Search Advertising (DSA). XR can learn more accurate models than the recently popular extreme classifiers which incorrectly assume strictly binary-valued label relevances. Traditional regression metrics which sum the errors over all the labels are unsuitable for XR problems since they could give extremely loose bounds for the label ranking quality. Also, the existing regression algorithms won't efficiently scale to millions of labels. This paper addresses these limitations through: (1) new evaluation metrics for XR which sum only the k largest regression errors; (2) a new algorithm called XReg which decomposes XR task into a hierarchy of much smaller regression problems thus leading to highly efficient training and prediction. This paper also introduces a (3) new labelwise prediction algorithm in XReg useful for DSA and other recommendation tasks.
Experiments on benchmark datasets demonstrated that XReg can outperform the state-of-the-art extreme classifiers as well as large-scale regressors and rankers by up to 50% reduction in the new XR error metric, and up to 2% and 2.4% improvements in terms of the propensity-scored precision metric used in extreme classification and the click-through rate metric used in DSA respectively. Deployment of XReg on DSA in Bing resulted in a relative gain of 58% in revenue and 27% in query coverage. XReg's source code can be downloaded from http://manikvarma.org/code/Xreg/download.html.
@InProceedings{Prabhu20,
author = "Prabhu, Y. and Kusupati, A. and
Gupta, N. and Varma, M.",
title = "Extreme Regression for Dynamic
Search Advertising",
booktitle = "Proceedings of the ACM International
Conference on Web Search and Data Mining",
month = "February",
year = "2020",
}
Edge sensing with micro-power pulse-Doppler radars is an emergent domain in monitoring and surveillance with several smart city applications. Existing solutions for the clutter versus multi-source radar classification task are limited in terms of either accuracy or efficiency, and in some cases, struggle with a trade-off between false alarms and recall of sources. We find that this problem can be resolved by learning the classifier across multiple time-scales. We propose a multi-scale, cascaded recurrent neural network architecture, MSC-RNN, comprised of an efficient multi-instance learning (MIL) Recurrent Neural Network (RNN) for clutter discrimination at a lower tier, and a more complex RNN classifier for source classification at the upper tier. By controlling the invocation of the upper RNN with the help of the lower tier conditionally, MSC-RNN achieves an overall accuracy of 0.972. Our approach holistically improves the accuracy and per-class recalls over machine learning models suitable for radar inferencing. Notably, we outperform cross-domain handcrafted feature engineering with purely time-domain deep feature learning, while also being up to ~3x more efficient than a competitive solution.
@InProceedings{Roy19,
author = "Roy*, D. and Srivastava*, S. and
Kusupati, A. and Jain, P. and
Varma, M. and Arora, A.",
title = "One Size Does Not Fit All:
Multi-Scale, Cascaded RNNs for
Radar Classification",
booktitle = "Proceedings of the ACM International
Conference on Systems for Energy-Efficient
Buildings, Cities, and Transportation",
month = "November",
year = "2019",
}
This paper develops the FastRNN and FastGRNN algorithms to address the twin RNN limitations of inaccurate training and inefficient prediction. Previous approaches have improved accuracy at the expense of prediction costs making them infeasible for resource-constrained and real-time applications. Unitary RNNs have increased accuracy somewhat by restricting the range of the state transition matrix's singular values but have also increased the model size as they require a larger number of hidden units to make up for the loss in expressive power. Gated RNNs have obtained state-of-the-art accuracies by adding extra parameters thereby resulting in even larger models. FastRNN addresses these limitations by adding a residual connection that does not constrain the range of the singular values explicitly and has only two extra scalar parameters. FastGRNN then extends the residual connection to a gate by reusing the RNN matrices to match state-of-the-art gated RNN accuracies but with a 2-4x smaller model. Enforcing FastGRNN's matrices to be low-rank, sparse and quantized resulted in accurate models that could be up to 35x smaller than leading gated and unitary RNNs. This allowed FastGRNN to accurately recognize the "Hey Cortana" wakeword with a 1 KB model and to be deployed on severely resource-constrained IoT microcontrollers too tiny to store other RNN models. FastGRNN's code is available at https://github.com/Microsoft/EdgeML/.
@InProceedings{Kusupati18,
author = "Kusupati, A. and Singh, M. and
Bhatia, K. and Kumar, A. and Jain, P. and Varma, M.",
title = "{FastGRNN}: A Fast, Accurate,
Stable and Tiny Kilobyte Sized
Gated Recurrent Neural Network.",
booktitle = "Advances in
Neural Information Processing Systems",
month = "December",
year = "2018",
}
The project aims at creating a efficient spatial embeddings for entities and types which would be useful for various downstream tasks such as Knowledge Base Completion, Fine-Type Tagging and Question Answering.
@article{Kusupati17,
author = "Kusupati*, A. and Dhoot*, A.
and Chakrabarti, S.",
title = "Efficient Spatial Representation
for Entity-Typing",
booktitle = "Undergraduate Thesis, CSE IIT Bombay",
year = "2016-17"
}
Open source repository for all the research outputs on resource efficient Machine Learning from Microsoft Research India. It contains scalable and multi-framework compatible implementations of Bonsai, ProtoNN, FastCells, EMI-RNN, S-RNN, a tool named SeeDot for fixed-point compilation of ML models along with applications such as on-device Keyword spotting and Gesturepod. EdgeML is under MIT license and is open to contributions and suggestions. Please cite the software if you happen to use EdgeML in your research or otherwise (use the latest bibtex from the repository in case this gets outdated)
@software{edgeml03,
author = {{Dennis, D.~K. and Gaurkar, Y. and Gopinath, S. and Gupta, C. and
Jain, M. and Kumar, A. and Kusupati, A. and Lovett, C.
and Patil, S.~G. and Simhadri, H.~V.}},
title = {{EdgeML: Machine Learning for resource-constrained edge devices}},
url = {https://github.com/Microsoft/EdgeML},
version = {0.3},
}