Karthik Ragunath Ananda Kumar

I’m Karthik Ragunath Ananda Kumar, a Master's student in the Computer Science department at UT Dallas researching on perception and (uncertainty-aware) deep reinforcement learning algorithms for motion planning in the Pattern Discovery and Machine Learning (PDML) Laboratory under the guidance of Prof. Feng Chen.

Also, I was an Artificial Intelligence Engineer - Machine Learning Intern at Samsung Research America (SPEEX-XR Labs - IMEX Div & NEON Team - STAR Labs) (Mountain View, CA, USA) from August 2022 till October 2023 , working on neural texture rendering for 2D and 3D avatars, and 3D neural mesh reconstruction to generate hyper-realistic human avatars and also on multimodal generative models to generate realistic head and body motions for 2D and 3D avatars.
Previously, I worked on multimodal generative models to generate facial actions for 2D avatars with lip sync.

I worked as an NLP / CV summer intern at Ancestry.com (Lehi City, Utah, USA) from May 2022 to August 2022 where I researched on entity linking, relationship extraction and summary generation neural network architectures .

In addition, I have 3+ years of experience working on applied machine-learning / deep-learning in search and ranking space at Mad Streen Den Inc from September 2018 to August 2021.

Artificial Intelligence Engineer - Machine Learning Intern, Samsung Research America (SRA) - SPEEX Labs, IMEX, MPS (Mountain View, California, USA)

  • Researched and implemented deep learning architectures for neural texture rendering and 3D head mesh fitting to generate hyper-realistic 3D human avatar talking heads. This research involved implementing deep learning models to parse facial information from 2D images, predicting 3DMM coefficients, and projecting 2D images into 3D space using the predicted 3DMM-coefficients. As part of this research, I also implemented a few novel ideas that involve blending UV texture maps generated from multiple 2D image sources to improve neural texture rendering on 3D (talking) head meshes.
  • Designed and implemented novel lightweight multimodal auto-regressive conditional variational auto-encoder and conditional auto-encoder deep learning architectures which are capable of generating lifelike 3D human body motions. These novel architectures were driven by input audio-context and auto-regressive pose estimations to generate smooth human-like body motions in terms of rotation angles and translation coordinate outputs for multiple joints in a real-time manner (on-device). The performances of these models were comparable to that of the heavier non-real-time SOTA models. This work of mine is currently in the evaluation phase in Samsung Research America to be published as a research paper in upcoming conferences.
  • Currently exploring deep learning architectures for Non-Rigid-ICP mesh registrations and generating volumetric 3D avatar talking head meshes from scratch using multiview 2D images (with camera calibrations).

Machine Learning Intern, Samsung Research America (SRA) - NEON Team, STAR Labs (Mountain View, California, USA)

  • Researching on facial-action recognition models and body-motion recognition models to recognize different facial expressions and human body movements in video frames. As part of this research, experimented on unsupervised clustering deep neural networks, temporal convolution networks, transformer architectures and few shot-learning approaches (Prototypical Networks and MAML). Achieved improvement on SOTA classification metrics in unsupervised deep clustering by introducing novelties in grouping algorithm.
  • Working on Motion Variational Auto-Encoders (MVAEs) to generate realistic controllable human action videos.
  • Built a PyTorch distributed training framework from scratch to make NEON’s deep-learning models to be trainable in a distributed manner. Integrated this framework into NEON's production system.
  • Working on feature extractors- {Contour, Keypoint, Crop} extractors and auto audio-annotator frameworks. Additionally, built front-end and backend systems to trigger the extractor and annotation pipeline processes and also track their status.
  • Performed preliminary literature survey and proposed a novel approach to sample uniform distribution across different labels in an unsupervised manner. (Yet to conduct experiments and validate).

Data Scientist - NLP and CV Research Intern, Ancestry.com (Lehi City, Utah, USA)

  • Researched on "Joint Entity and Relationship Extraction" neural network models to extract relationship between entities in multi-page documents like books, blog posts, etc and convert them into interpretable graphs.
  • As part of this research work, I worked on ensembling deep learning models from multiple SOTA research papers to solve the problems of:
    1. (i) capturing long range entity relationship dependencies.
    2. (ii) subject entity overlap
    3. (iii) entity pair overlap problems
    4. (iv) coreference resolution in extracting entity relationships, etc.
  • Got selected to present my summer intern work in-front of executive board at Ancestry.

Software Engineer - Machine Learning/Deep Learning and Search, Mad Street Den Inc

Deep Learning and Machine Learning

  • Designed and implemented Parts of Speech (PoS), Named Entity Recognition (NER), Dependency Parser Neural Network Models; LSTM based Auto-Correction and Auto-Suggestion models to optimize text-search system at production scale.
  • Designed a document searching system which involved working with transformer models to generate search embeddings.
  • Designed a text classifier framework to classify e-commerce products using XGBoost, MLP and SVM models.
  • Experimented with XGBoost’s Learning to Rank Algorithms for fine tuning personalisation models.
  • Designed recommendation algorithms using Apache Solr's boost and filter functions based on buy and search histories.

Distributed Systems Engineering

  • Core member of the team which built and tuned Apache Solr (and Zookeeper) Clusters for enabling searching and listing operations on e-commerce websites.
  • Scaled Apache Solr’s Distributed Computing Infrastructure to handle up to 40,000 requests per minute.
  • Worked on building data pipelines for powering real time search requests using AWS SNS, Redis Queues, etc.
  • Worked on setting up and tuning of Spark clusters optimizing (Py)Spark queries to optimize data digestion pipelines.
  • Performed database backup, synchronization and migration operations.

Member Technical Staff (Software Engineer), Zoho Corporation

  • Worked extensively in building libraries using Apple’s Core Data framework for powering offline iOS applications.
  • Worked on implementing OCR algorithms on receipt images to extract information from them in the Zoho Expense iOS application.
  • Built frameworks for handling image data and rendering custom animations in iOS applications.
  • Completely redesigned an iOS application called "Zoho Invoice Generator" and released it in the App Store.

Thesis Research - Perception and Motion Planning Deep Reinforcement Learning

Pattern Discovery and Machine Learning (PDML) Lab, University of Texas at Dallas

As part of my on-going thesis research under the guidance of Prof. Feng Chen on Perception and Motion Planning components of Autonomous Driving Systems in the Pattern Discovery and Machine Learning (PDML) Laboratory at UT Dallas, I am experimenting with Deep Reinforcement Learning Algorithms, namely, Proximal Policy Optimization (PPO) and Soft Actor-Critic algorithms (SAC) powered by agent’s camera POV image features and also Uncertainty-Aware Object Detection components. The Uncertainty-Aware Object Detection is particularly designed to compute Out-of-Distribution (OOD) probabilities of the objects identified by the object detection component in order to augment the motion planning deep reinforcement learning algorithms. The deep reinforcement learning algorithms were trained on CARLA Autonomous Driving Simulator Engine. The simulator is wrapped as a custom OpenAI gym environment so that data streamed from the simulator engine can be accessed in real time (with synchronization) when used for training with Deep RL algorithms with the objective to plan the motion path of the agent (vehicle).

***Complete research code is yet to be exposed to a public Github-Repository since we are planning for a paper submission in the near future.***

Exploring Usage Of Graph Neural Networks For Encoder Networks

University of Texas at Dallas

Researched on exploring the usage of Graphical Neural Network (GNNs) variants for designing a novel encoder architecture (as part of an encoder-decoder architecture) to create abstract summaries utilizing “Joint Entity and Relationship Extraction” based approaches at UT Dallas.

Personal Projects

Learning for 3D Vision

Solving assignments and projects of the course - ”Learning for 3D Vision” offered by Carnigie Mellon University (CMU) in Spring 2023 in order to understand the fundamentals of 3D vision deep learning.

https://github.com/Karthik-Ragunath/3d-deep-learning {Work-In-Progress}

3D Avatar Mesh Fitting

Working on a project to generate ground-truth 3D scans from skin interpolations and joints for which I have designed (and implemented) three different neural network architectures, namely:

  1. Multi-Pose Encoder With Multi-Expert Decoder Auto-Encoder Neural Network Architecture
  2. Multi-Pose Multi-Joint Encoder With Multi-Expert Decoder Auto-Encoder Neural Network Architecture
  3. Multi-Pose Encoder With Multi-Expert Decoder + Laplacian Smoothing Loss Auto-Encoder Neural Network Architecture


***This is under evaluation for a competitive submission and hence not exposed in a public GitHub repository.***

Convert Images/Videos to Anime Styled Images/Videos With Conditional-GAN and Stable-Diffusion

Exploring Conditioanl-GAN models for converting photos/videos to anime styles. Also, exploring text-to-image Stable-Diffusion models to add custom animations into the generated anime styled images. {{Work-In-Progress}}

***This project is currently under evaluation for a competitive submission and hence not exposed in a public GitHub repository***

GAN variants from scratch

Working on a competitive submission to create following GAN model variants which is trainable on any given image dataset:

  1. DCGAN (Deep Convolution Generative Adversarial Network)
  2. C-DCGAN (Conditional Deep Convolution Generative Adversarial Network)
  3. Wasserstein-GP GAN (Wasserstein-Gradient Penalty Generative Adversarial Network)
  4. VAE-GAN (Variational Auto-Encoder Based Generative Adversarial Network)


***This is under evaluation for a competitive submission and hence not exposed in a public GitHub repository.***

Exploring Stable-Baselines3 Deep Reinforcemnt Learning Algorithms

Explored Stable-Baselines3 framework for training custom Deep Reinforcement Learning models involving Proximal Policy Optimization (PPO) and Soft-Actor Critic (SAC) algorithms in OpenAI Gym environment.

https://github.com/Karthik-Ragunath/pytorch_car_caring

Explored spaCY's Framework For Implementing NLP Algorithms

Explored spaCY's off-the-shelf Parts of Speech, Named Entity Recognition, Dependency Parser models and also spaCY's custom training components to modify Neural Network architectures (other than the ones provided off-the-shelf) to obtain a preliminary understanding semantic text parsing NLP algorithms.

https://github.com/Karthik-Ragunath/DeepLearning-Projects/tree/master/Dependency-Parser-Basics

Machine Learning Algorithms From Scratch

Implemented and trained the following machine learning algorithms from scratch to obtain a strong mathematical understanding of the ML algorithms.

  1. Implemented SVM’s in Primal and Dual form with/ without Slack Formation applying Polynomial and Gaussian kernels.
  2. Built decision trees from scratch with information gain as the parameter to split the trees.
  3. Built Sub-Gradient Descent and Stochastic Sub-Gradient Descent models from scratch.
  4. Built AdaBoost and Coordinate-Descent Decision Tree Classifiers from scratch.
  5. Built frameworks Clustering and PCA-SVM Classifiers from scratch.


https://github.com/Karthik-Ragunath/MSCS-Course-Work/tree/master/ML_Spring2022

Music Recommendation System

Built a music recommendation system to recommend songs based on user’s preferences. Audio files were embedded into vectors and ElasticSearch clusters were used to perform KNN search to recommend matches.

Achievements in Competitive Programming

  1. GitHub Repo - https://github.com/Karthik-Ragunath/competitive_programming
  2. https://www.codechef.com/users/karthik6995

  • Achieved four star rating in competitive programming contests in CodeChef in May 2018.
  • Achieved a global rank of 279 in CodeChef June CookOff 2018 Division 1 competitive programming contest.
  • Achieved a global rank of 111 in CodeChef May Challenge 2018 Division 2 competitive programming contest.
  • Achieved a global rank of 71 in LoC (Lord’s Of Code) contest on the CodeChef platform, June 2018.
  • Achieved a global rank of 243 in CodeChef April Lunchtime 2018 Division 2 competitive programming contest.
  • National Rank of 191 and Global Rank of 202 in TCS CodeVita 2016 (Competitive Programming Contest).
  • “Top Coder” award winner in College (2016) based on the results of weekly competitive programming competition.

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