DRIFT open dataset: A drone-derived intelligence for traffic analysis in urban environmen

Reliable traffic data are essential for understanding urban mobility and developing effective traffic management strategies. This study introduces the DRone-derived Intelligence For Traffic analysis (DRIFT) dataset, a large-scale urban traffic dataset collected systematically from synchronized drone videos at approximately 250 meters altitude, covering nine interconnected intersections in Daejeon, South Korea. DRIFT provides high-resolution vehicle trajectories that include directional information, processed through video synchronization and orthomap alignment, resulting in a comprehensive dataset of 81,699 vehicle trajectories. Through our DRIFT dataset, researchers can simultaneously analyze traffic at multiple scales - from individual vehicle maneuvers like lane-changes and safety metrics such as time-to-collision to aggregate network flow dynamics across interconnected urban intersections. The DRIFT dataset is structured to enable immediate use without additional preprocessing, complemented by open-source models for object detection and trajectory extraction, as well as associated analytical tools. DRIFT is expected to significantly contribute to academic research and practical applications, such as traffic flow analysis and simulation studies. The dataset and related resources are publicly accessible at https://github.com/AIxMobility/The-DRIFT.

FLAMe: Federated Learning with Attention Mechanism using Spatio-Temporal Keypoint Transformers for Pedestrian Fall Detection in Smart Cities

In smart cities, detecting pedestrian falls is a major challenge to ensure the safety and quality of life of citizens. In this study, we propose a novel fall detection system using FLAMe (Federated Learning with Attention Mechanism), a federated learning (FL) based algorithm. FLAMe trains around important keypoint information and only transmits the trained important weights to the server, reducing communication costs and preserving data privacy. Furthermore, the lightweight keypoint transformer model is integrated into the FL framework to effectively learn spatio-temporal features. We validated the experiment using 22,672 video samples from the "Fall Accident Risk Behavior Video-Sensor Pair data" dataset from AI-Hub. As a result of the experiment, the FLAMe-based system achieved an accuracy of 94.02% with about 190,000 transmission parameters, maintaining performance similar to that of existing centralized learning while maximizing efficiency by reducing communication costs by about 40% compared to the existing FL algorithm, FedAvg. Therefore, the FLAMe algorithm has demonstrated that it provides robust performance in the distributed environment of smart cities and is a practical and effective solution for public safety.