Profile

I received my PhD degree in Computer Science, working with Christian S. Jensen, from Aalborg University, Denmark in 2000 and a degree in Information Systems (Magister) from Johannes Kepler Universität (JKU) Linz, Austria. I had the privilege to work as a research assistant for Max Egenhofer at the Department of Spatial Information Science and Engineering, University of Maine, USA (1996-97), as an assistant professor at the Department of Computer Science, Aalborg University, Denmark (2000-02), as a researcher at the Computer Technology Institute, Greece (2002-2008), and as a senior researcher and founder of the Geoinformatics Department, working with Timos Sellis at IMSI, Research Center “ATHENA” in Athens, Greece (2008-2012).

RESEARCH - My early research primarily focused on map-matching and map-construction algorithms, particularly within the realms of spatiotemporal databases and transportation systems. I developed a robust map-matching algorithm to convert large volumes of vehicle-tracking data into accurate travel times, which became crucial for real-time traffic assessments and optimizing logistics. In addition, I worked on map-construction algorithms that generated road networks from vehicle trajectories, improving the accuracy and efficiency of spatial data handling. I also contributed to database management for trajectory datasets, creating the TB-tree index to handle spatiotemporal data and frameworks to manage uncertainty in trajectory modeling. My work in query optimization and routing led to the development of efficient shortest-path algorithms, now used in commercial fleet management and other transportation systems. Since joining Mason I have expanded my research into user-generated geospatial content, focusing on improving the integration and quality of data from sources like point clouds, travel blogs, and crowdsourced information. I’ve applied natural language processing (NLP) to better understand how users express spatial relationships and developed advanced data fusion techniques to merge diverse data sets. I’ve also broadened my research to include agent-based modeling (ABM) and urban simulations, using AI and machine learning to model human mobility patterns and urban dynamics. My recent work has focused on applications like trajectory anomaly detection, urban mobility assessments using large language models (LLMs), and GeoAI for public health, aiming to provide innovative solutions for urban planning, transportation, and public health challenges.

PUBLICATIONS - more than 100 articles in international journals and refereed conferences attracting more than 7000 citations based on Google Scholar.

PROJECTS - support by NSF, DARPA, DOD, GMU, the European Commission and the Greek General Secretariat of Science and Technology.

Supported by a strong TEAM of students and postdocs.

TEACHING - I teach courses related to geospatial data management, Linked Data, Web application development using open-source software, and data visualization.