Optimization Techniques for Cell-Free Massive MIMO System
Chamalee Wickrama Arachchi. (2019). "Optimization Techniques for Cell-Free Massive MIMO System." University of Oulu, Master’s Thesis.
CV
Education
Ph.D. in Computer Science, University of Helsinki, 2021–2025
Specialization: Data Mining & Machine Learning
Experience in graph algorithms, dense subgraph discovery, temporal networks, and optimization.M.Sc. in Wireless Communications Engineering, University of Oulu, 2018–2020
Distinction Pass (GPA 4.7/5), Thesis Grade: 5/5B.Sc. (Hons) in Electronic & Telecommunication Engineering, University of Moratuwa, 2011–2016
First Class Honours (GPA 3.7/4.2)
Work Experience
Software Engineer – IFS R&D International (Pvt) Ltd
July 2017 – April 2018
- Development for Manufacturing, Supply Chain, Finance and Extensions of the IFS ERP.
- Automated Jenkins build steps via PowerShell scripting.
- OracleDB administration, Git/Bitbucket workflow integration.
Software Engineer – DirectFN (Pvt) Ltd
April 2016 – June 2017
- Implemented financial web features using EmberJS, HTML, CSS for stock exchanges.
- Delivered sprint-based features under Agile development.
Technology Intern – Virtusa (Pvt) Ltd
Oct 2014 – March 2015
- Troubleshooting firmware and mobile applications (C for embedded systems, J2ME).
- Worked on smart wearable ECG monitoring systems.
Freelance Software Developer & Mathematics Tutor
2011–2016
- Delivered custom inventory & sales software for retail businesses.
- Taught advanced mathematics to high school students.
Skills
Programming & Tools
- Python, C, MATLAB, Java, VBA
- Git, Linux, JIRA, Confluence, REST, Postman, Scrum
Databases
- SQL, Oracle SQL, MongoDB, PostgreSQL
Frontend
- HTML, CSS, Javascript, EmberJS
Cloud and Data Visualization
- AWS, Power BI, Tableau
Other
- Excel, PowerPoint, Automation scripting, data pipelines
Publications
Node ranking in labeled networks
Chamalee Wickrama Arachchi and Nikolaj Tatti. (2023). "Node ranking in labeled networks." SIAM International Conference on Data Mining.
Jaccard-constrained dense subgraph discovery
Chamalee Wickrama Arachchi and Nikolaj Tatti. (2024). "Jaccard-constrained dense subgraph discovery." Machine Learning: 1–23.
Recurrent segmentation meets block models in temporal networks
Chamalee Wickrama Arachchi and Nikolaj Tatti. (2024). "Recurrent segmentation meets block models in temporal networks." Machine Learning: 1–31.
Dense Subgraph Discovery Meets Strong Triadic Closure
Chamalee Wickrama Arachchi, Iiro Kumpulainen, and Nikolaj Tatti. (2024). "Dense Subgraph Discovery Meets Strong Triadic Closure." ACM KDD Conference.
Fair Densest Subgraph Across Multiple Graphs
Chamalee Wickrama Arachchi and Nikolaj Tatti. (2024). "Fair Densest Subgraph Across Multiple Graphs." ECML PKDD.
Methods for Finding Structures in Feature-rich Graph Networks
Chamalee Wickrama Arachchi. (2025). "Methods for Finding Structures in Feature-rich Graph Networks." University of Helsinki, Doctoral Dissertation.
Talks
Recurrent Segmentation Meets Block Models in Temporal Networks
Talk at Discovery Science Conference 2022, Montpellier, France
Node Ranking in Labeled Networks
Talk at SIAM SDM Conference, Minneapolis, Minneapolis, USA
Jaccard-constrained Dense Subgraph Discovery
Talk at Discovery Science Conference 2023, Porto, Portugal
Dense Subgraph Discovery Meets Strong Triadic Closure
Talk at ACM KDD Conference, Barcelona, Barcelona, Spain
Fair Densest Subgraph Across Multiple Graphs
Talk at ECML PKDD, Vilnius, Vilnius, Lithuania
Teaching
Service and Leadership
- Reviewer: Transactions on Knowledge Discovery from Data, 2024
- Reviewer: International Conference on Discovery Science, 2024
- Teaching Assistant:
- Introduction to Artificial Intelligence, Fall 2021
- Introduction to Machine Learning, Fall 2023
Code Repositories
- STC-dense subgraphs project — https://version.helsinki.fi/dacs/dense-stc-subgraph
- Fair densest subgraph project — https://version.helsinki.fi/dacs/fair-densest-subgraph
- Jaccard-constrained dense subgraph project — https://version.helsinki.fi/dacs/jaccard-constrained-densest-subgraph
- Node ranking in labeled networks — https://version.helsinki.fi/chamwick/node-ranking-in-labeled-networks
- Recurrent segmentation with block models — https://version.helsinki.fi/dacs/recurrent-segmentation-temporal-network
Languages
- English – Fluent
- Swedish – B1
Referees
Prof. Nikolaj Tatti
Department of Computer Science, University of Helsinki
Email: nikolaj.tatti@helsinki.fi
Prof. Michael Mathioudakis
Department of Computer Science, University of Helsinki
Email: michael.mathioudakis@helsinki.fi