About

Hello! My name is Ajay Krishna Vajjala.

I am a third year Ph.D. candidate at George Mason University (GMU) studying Computer Science. I recieved my Bachelor's and Master's degrees in Computer Science from the College of Engineering and Computing at George Mason University. I started the Ph.D. program in the Fall of 2021, and i'm currently working under Dr. David S. Rosenblum. I am broadly interested in machine learning, data mining, and information retrieval, with an emphasis on transfer learning for recommender systems, such as cross-domain recommendation, to provide relevant and personalized recommendations for users.

Basic Information
Age:
25
Email:
akrish@gmu.edu
Address:
Virginia, USA
Language:
English
Latest News

April 2024 - Passed my PhD Proposal Defense, and advanced to Candidacy!

April 2024 - Presented my paper at the SIAM International Conference on Data Mining (SDM) in Houston, Texas!

April 2024 - Invited as a speaker at the GMU Software Engineering Seminar series, where I gave a talk on my latest research!

March 2024 - My paper, titled "Analyzing the Impact of Domain Similarity: A New Perspective in Cross-Domain Recommendation," has been accepted to the International Joint Conference on Neural Networks (IJCNN 2024) !

February 2024 - Accepted an offer to join Microsoft Research (MSR) as a Research Intern for the summer of 2024!

December 2023 - My paper, titled "Vietoris-Rips Complex: A New Direction for Cross-Domain Cold-Start Recommendation," has been accepted to the SIAM International Conference on Data Mining (SDM 2024)!

December 2022 - Completed M.S. in Computer Science from GMU!

September 2022 - Attended the ACM Conference on Recommender Systems (RecSys), and served as a student volunteer!

April 2022 - Passed my written and oral PhD Comprehensive Exams!

January 2022 - Accepted an offer to start as a Graduate Research Assistant at GMU!

August 2021 - Accepted an offer to start as a Graduate Teaching Assistant at GMU!

May 2021 - Joined an interdisciplinary research team at the Center for Adaptive Systems of Brain-Body Interactions (CASBBI)!

February 2021 - Admitted into the Computer Science PhD Program at George Mason University!

Demeber 2020 - Graduated with a B.S in Computer Science from George Mason University!

Publications
Analyzing the Impact of Domain Similarity: A New Perspective in Cross-Domain Recommendation

A. Krishna Vajjala, Ar. Krishna Vajjala, Z. Zhu, and D. Rosenblum. "Analyzing the Impact of Domain Similarity: A New Perspective in Cross-Domain Recommendation." In Proceedings of the IEEE International Joint Conference on Neural Networks (IJCNN 2024), Yokohama, Japan, June 30th to July 5th, 2024.

Paper | Code

Vietoris-Rips Complex: A New Direction for Cross-Domain Cold-Start Recommendation

A. Krishna Vajjala, D. Meher, S. Pothagoni, Z. Zhu, and D. Rosenblum. "Vietoris-Rips Complex: A New Direction for Cross-Domain Cold-Start Recommendation." In Proceedings of the SIAM International Conference on Data Mining (SDM 2024), Houston, TX, U.S. 18th-20th April, 2024. [Acceptance Rate: 29.2%]

Paper | Code


Work Experience

May 2022 - Present

George Mason University
Graduate Research Assistant
Large Language Models (LLMs) for Cross-Domain Recommendation

I am working on a project to enhance cross-domain recommendation capabilities using state-of-the-art language models. By introducing zero-shot and few-shot prompting techniques, I optimized the recommendation process across various domains. The project involves fine-tuning open-source models like LlaMA-2 with parameter sizes ranging from 7B to 70B. This process was conducted using parameter-efficient fine-tuning (PEFT) methods. A critical component of the project was the use of QLoRA for fine-tuning LLMs on dual-domain data, improving the models' recommendation performance. The fine-tuning process was powered by multiple A100 GPUs, ensuring efficient handling of large-scale data and model parameters. I utilized Weights and Biases for visualizing the fine-tuning process of QLoRA, allowing for a detailed and transparent view of the model's performance enhancements. This comprehensive approach demonstrated the potential of LLMs in revolutionizing the field of recommender systems through advanced transfer learning techniques.

Vietoris-Rips Complex: A New Direction for Cross-Domain Cold-Start Recommendation

I conducted reasearch that integrated the Rips Complex from computational geometry with deep learning techniques. The primary goal was to effectively transfer user preferences across varying domains, leading to the creation of novel user profiles tailored for personalized recommendations. The approach was particularly groundbreaking in addressing extreme cold-start scenarios, registering a substantial performance boost of over 20% compared to existing leading methods. This project involved meticulous fine-tuning using 5-fold cross-validation to enhance the model's efficacy on novel data. Technologically, it leaned heavily on Python and Tensorflow, with all complex computations being adeptly handled by the powerful Nvidia A100 GPU.

Impact of Domain Similarity: A New Perspective in Cross-Domain Recommendation

I leveraged Python, GloVe pre-trained embeddings, and BERT techniques from NLP to develop sophisticated domain similarity metrics. This led to the formulation of baseline cross-domain recommendation algorithms, taking advantage of the open-source Recbole-CDR library. The algorithms were rigorously assessed across a diverse array of 18 domain combinations, benchmarked against three industry-leading cross-domain algorithms. Intriguingly, the findings revealed that the recommendation efficacy was largely invariant to the specific domain combinations, a conclusion drawn using a paired t-test. For optimum efficiency, all computational processes and experiments were powered by the high-performance Nvidia A100 GPU.

Conditional Generative Adverserial Networks for Cross-Domain Recommendation

I utilized Python, TensorFlow, and the Nvidia A100 GPU to develop a cross-domain recommender system using a conditional GAN. The project centered around the synthetic generation of target domain item embeddings, which were seamlessly infused with source domain data. Furthermore, these synthesized embeddings were combined with pre-existing user embeddings, providing enhanced personalized recommendations. As a testament to the robustness of the approach, we conducted extensive tests using various top-tier cross-domain recommendation algorithms. The results were promising: our model outperformed the competition, registering a preliminary performance surge of 5% over conventional benchmarks.

May 2021 - May 2022

GMU - Center of Adaptive Systems of Brain and Body Interaction
NSF National Research Trainee Fellow
Reentry and Corrections

Developed a website that provides incarcerated individuals with information on reentry and social service supports that they can use upon reentry from jail. The application’s main objective is to provide incarcerated individuals autonomy over their reentry experience while providing these services in a easily accessible way. The website was built using React for front-end, Node for back-end, and MySQL for the database. Partnered with American Prison Data Systems (APDS) and DJ Jail to pilot the website on APDS tablets across jails in the U.S. as soon as 2023.

Aug 2021 - May 2022

George Mason University
Graduate Teaching Assistant
Instructor for Introduction to Programming Class (CS112)

Taught 60 person labs twice a week for two semesters, while creating programming assignments for the students to work on. Held office hours every week to help students understand programming concepts, and worked on grading labs and programming assignments for over 100 students.

Jan 2020 - Dec 2020

George Mason University
Undergraduate Teaching Assistant

Working as a teaching assistant for Data Mining Course at GMU. Assisted students on machine learning algorithms, and help them understand machine learning and data science concepts (Classification and Clustering Algorithms). Help students work with KNN, Neural Networks, K-Means clustering, Decision Trees, and held office hours every week.

May 2019 - Aug 2019

International Software Systems Inc.
Software Engeneering Intern

Worked on application for hospitals to keep track of patient and staff data in hospitals. I developed API’s to retrieve patient information, doctor information, and track call logs. I used Node JS for developing API’s, and React JS for frontend development. The data for the application was stored in AWS S3, and it was deployed on an EC2 Instance. In addition, a CI/CD pipeline was set in place for developing the web application.

Education

Aug 2021 - Present

Doctor of Philosophy (Ph.D.)
Ph.D. in Computer Science

George Mason University

Cousework: Theory of Computation, Graph Algorithms, Research Methods in CS

Jan 2021 - Dec 2021

Master's Degree
Master of Computer Science

George Mason University

Cousework: Mining Massive Datasets with Map Reduce, Component-Based Software Development, Artificial Intelligence

Aug 2017 - Dec 2020

Bachelor's Degree
Bachelor of Computer Science

George Mason University

Cousework: Operating Systems, Analysis Of Algorithms, Data Mining, Data Structures, Object Oriented Programming

Professional Skills
Python
95%
Java
95%
Node
75%
React
65%
C & C++
80%
SQL
80%
Hadoop
70%
AWS EMR
80%
Keras/Tensorflow
90%
PySpark
85%
Contact Me
Feel free to contact me

Address

Virginia, USA

Email

akrish@gmu.edu