ABOUT ME
I am a postdoctoral research fellow in the Department of Computer Science and Engineering at Hong Kong University of Science and Technology.
Previously, I was a postdoctoral research associate at the University of Hong Kong. I obtained my Ph.D. degree from University of Ioannina, Computer Science and Engineering Department, working with Prof. Nikos Mamoulis.
RESEARCH INTERESTS
My research interests lie in the area of spatiotemporal data management and flow analytics in large graphs, with a particular focus on a new class of networks called Temporal Interaction Networks (TINs). These networks model dynamic systems where entities exchange quantities, such as financial transactions, transportation flows, or communication data.
Over the past few years, I have been developing efficient solutions to optimize classical problems—such as max-flow computation—by introducing the temporal dimension. Currently, my work focuses on data provenance analytics in large graphs, with an emphasis on designing techniques to trace the origin of transmitted quantities in graph-structured data.
Recently, I have also started exploring the Text-to-SQL domain, focusing on addressing challenges related to text ambiguity in natural language database queries.
RECENT NEWS
- 2025-10: Serving as PC member for PVLDB 2026 and ICDE 2026, and as a co-chair for TKDE Poster track @ICDE 2026.
- 2025-09: One paper accepted to SSTD 2025.
- 2025-05: Started position as Postdoctoral Research Fellow at HKUST.
- 2024-06: One paper accepted to PVLDB 2024 - "A Sampling-based Framework for Hypothesis Testing on Large Attributed Graphs".
- 2023-04: Successfully defended Ph.D. thesis on "Flow Analytics in Large Graphs".
- 2022-04: Paper accepted to ICDE 2022 - "Provenance in Temporal Interaction Networks".
SELECTED PUBLICATIONS
Data-Aware Socratic Query Refinement in Database Systems
Ruiyuan Zhang, Chrysanthi Kosyfaki, Xiaofang Zhou
Under review @DEFT, ICDE 2026
BEACON: A Benchmark for Efficient and Accurate Counting of Subgraphs
Xiangju Zhu, Mohammad Matin Najafi, Chrysanthi Kosyfaki, Xiaodong Li, Reynold Cheng, Laks V.S. Lakshmanan
Under review @ICDE 2026
Generalized Origin-Destination-Time Flow Patterns
Chrysanthi Kosyfaki, Nikos Mamoulis, Reynold Cheng, Ben Kao
SSTD 2025
A Sampling-based Framework for Hypothesis Testing on Large Attributed Graphs
Yun Wang, Chrysanthi Kosyfaki, Sihem Amer-Yahia, Reynold Cheng
PVLDB 2024
Provenance in Temporal Interaction Networks
Chrysanthi Kosyfaki, Nikos Mamoulis
ICDE 2022
Flow Computation in Temporal Interaction Networks
Chrysanthi Kosyfaki, Nikos Mamoulis, Evaggelia Pitoura, Panayiotis Tsaparas
ICDE 2021
Flow Motifs in Interaction Networks
Chrysanthi Kosyfaki, Nikos Mamoulis, Evaggelia Pitoura, Panayiotis Tsaparas
EDBT 2019
INVITED TALKS
Temporal Provenance in Temporal Interaction Networks
University of Amsterdam
October 2025
Flow Analytics in Large-Scale Networks
Hong Kong University of Science and Technology
November 2024
STUDENT SUPERVISION
PhD Students (HKUST)
Sau Lai YIP - Working on Text-to-SQL problems
Nujibieke Shabuerjiang - Working on spatiotemporal data management topics
Jounghoon Kim - Working on ANNS problems
PhD Students (HKU)
Yun (Carrie) Wang - Working on hypothesis testing on graphs
Xiangju Zhu - Working on subgraph counting problems
Mohammad Matin Najafi - Worked on subgraph counting problems, now a researcher at Huawei, Hong Kong
Bachelor Students (University of Ioannina)
Ioanna Papayianni (2020) - Thesis: Developing efficient algorithms for analyzing flow patterns in large networks
Dimitris Zervas (2021) - Thesis: Detecting the origin of transactions in the Bitcoin Network
Sotiria Kastana (2021) - Thesis: Design and development of a synthetic indoor movement generator
Vasileios Georgoulas (2023) - Thesis: A web application for passenger movement with public transport
TEACHING EXPERIENCE
Network Data Analytics
Instructor, The University of Hong Kong
Spring 2025
Complex Data Management
Teaching Assistant, University of Ioannina
Spring 2019-2023
Object Oriented Programming
Teaching Assistant, University of Ioannina
Spring 2018
Introduction to Programming
Teaching Assistant, University of Ioannina
Fall 2017-2022
