Air pollution poses a serious environmental and public health challenge, particularly in rapidly industrializing regions of China. Accurate forecasting of air quality is essential for effective pollution management and policy intervention. However, existing prediction models often fail to capture the complex spatial and temporal dependencies within multi-source environmental data.
To address this limitation, this study proposes an Attention-Enhanced Spatio-Temporal Graph Convolutional Network (AE-STGCN) that integrates spatial–temporal attention mechanisms with graph convolutional learning. The model fuses heterogeneous datasets—including air pollutant measurements, meteorological variables, and urban point-of-interest (POI) data—into a unified grid-based feature representation. By dynamically learning the significance of different spatial regions and temporal intervals, AE-STGCN enhances predictive accuracy and interpretability.
Architecture of the proposed AE-STGCN model.
RL agent with proactive Dynamic obstacle avoidance
This ongoing research focuses on developing an intelligent obstacle avoidance system for autonomous mobile robots using real-time video input. The project integrates computer vision and deep reinforcement learning (DRL) to enable robots to perceive and navigate complex dynamic environments efficiently.
A YOLO-based object detection model is used to identify and classify moving obstacles, while DRL algorithms such as DQN and PPO are applied to optimize navigation strategies through continuous learning and interaction with the environment. The entire system is developed and tested in the ROS and Gazebo simulation platforms, allowing for experimentation under variable conditions like sensor noise, lighting, and motion dynamics.
The goal of this research is to create a robust end-to-end framework that fuses visual perception and decision-making, enabling autonomous systems to adaptively respond to real-world scenarios with improved safety, precision, and reliability.
A project demonstrating how probabilistic filtering can recover smooth motion estimates from noisy data.
Problem: Position sensors often produce jittery and unreliable readings during robot motion.
Method: Implemented a 2D Kalman Filter that combines a constant-velocity motion model with noisy position measurements to infer true position and velocity.
Result: Achieved smooth, noise-reduced trajectories and accurate velocity estimation—improving tracking stability for robotics and navigation systems.
Keywords: State Estimation, Sensor Fusion, Robotics, Applied Mathematics
A probabilistic modeling project that focuses on understanding uncertainty in real-world sensor readings.
Problem: Traditional linear regression fails to express confidence in predictions, limiting trust in noisy sensor systems.
Method: Built a Bayesian linear regression framework to simulate sensor readings and compute predictive distributions with credible intervals.
Result: Generated interpretable predictions with quantified uncertainty, enhancing model transparency and decision reliability in sensor-based systems.
Keywords: Bayesian Inference, Uncertainty Quantification, Applied Machine Learning
Bayesian regression fit on simulated sensor data.
The gray points represent noisy sensor readings. The blue line shows the predicted mean, while the shaded area indicates the 95% credible interval — capturing uncertainty in sensor behavior.
This project is a Python-based automated testing framework built using Pytest to validate RESTful APIs. It provides a complete testing pipeline — from executing API test cases to generating structured JSON reports and interactive visualizations of the results.
The goal is to make API quality assurance efficient, repeatable, and data-driven. The framework not only verifies API responses but also gives teams a quick, visual understanding of test outcomes and performance trends.
API Test Results Overview
API Validation
The Client Automation Test Framework is a Python-based automated testing system designed to validate client-side applications and APIs through scripted test cases, automated execution, and dynamic reporting.
It ensures functional reliability, performance stability, and data accuracy of client-facing systems by automating repetitive testing tasks, minimizing manual intervention, and producing detailed analytics for each test cycle.
This framework provides an end-to-end automated testing pipeline — covering API validation, client workflow verification, and visual reporting.
The E-Commerce Checkout API Performance Testing project focuses on evaluating and optimizing the performance, scalability, and reliability of an e-commerce checkout service.
This project simulates real-world user behavior — such as adding products to the cart, calculating totals, applying discounts, and completing payments — and measures how efficiently the backend API handles varying loads.
The objective is to identify bottlenecks, measure response times, and ensure that the checkout system can handle high traffic without performance degradation.
E-commerce checkout Performance Graph
Users vs Response time
This project focuses on testing and documenting an E-commerce Checkout API using both manual and automated QA methods. It covers the full QA lifecycle — from requirement analysis and test planning to automation, performance testing, and reporting.
The goal was to ensure the checkout workflow (cart, order, payment) runs smoothly, efficiently, and securely. Using tools like Pytest, Postman, Docker, and Plotly, the project validates API reliability and visualizes test outcomes for better decision-making.
Convolutional Neural Network (CNN) to classify clothing items in images using the Fashion MNIST dataset. The process includes data loading, preprocessing, model creation, training, evaluation, and visualization. The dataset was normalized and split into training, validation, and test sets to prepare it for CNN training. A custom CNN architecture was designed and trained using the Adam optimizer and sparse categorical cross-entropy loss function. The model achieved an accuracy of approximately 90.66% on the test dataset.
CNN Model Architecture
Visualization of customer clusters based on Quantity and Unit Price using the K-means algorithm.
the K-means clustering algorithm, an unsupervised machine learning technique, to segment customers based on their purchasing patterns using the Online Retail Dataset from the UCI Machine Learning
Repository. The dataset includes transactional details such as quantity, price, and purchase frequency, which were preprocessed and standardized for clustering analysis. The optimal number of clusters was determined using the Elbow Method, and the model successfully grouped customers into distinct segments that reflect different purchasing behaviors. The results provide valuable insights into customer groups such as loyalcustomers, high-value buyers, and infrequent shoppers.
This study compares three prominent algorithms—Breadth-First Search (BFS), Depth-First Search (DFS), and A*—to solve the 8-puzzle problem. Each algorithm was implemented and assessed based on key metrics, including execution time, memory usage, and solution path length. The results reveal that BFS and A* guarantee the shortest path to the solution, with A* showing better scalability due to its heuristic-based approach. DFS, while less memory-intensive, tends to generate suboptimal solutions due to its depth-first nature.
Performance metrics Comparison Barchart
Data Flow in the System
Key findings reveal that Merge Sort and Quick Sort outperform Bubble Sort in terms of execution time and number of comparisons for larger datasets, confirming their O (n log n) efficiency. Bubble Sort, while simpler, is significantly slower and performs better only on very small or nearly sorted datasets. Merge Sort exhibited consistent performance across all distributions, while Quick Sort's efficiency depended on the pivot selection.
The system integrates these cryptographic techniques into a seamless workflow that encrypts messages, signs them, and verifies their integrity upon receipt. Implemented in Python, the system leverages the PyCryptodome library for cryptographic operations and provides a user-friendly interface using Gradio for real-time interaction. Experimental results demonstrate the system's effectiveness in achieving secure, authenticated, and tamper-proof communication, making it a valuable contribution to modern cryptographic applications. This study also highlights the practicality and robustness of combining multiple cryptographic algorithms to address the multifaceted requirements of secure communication.
Overall System Architecture