University of Toronto   Faculty of Applied Science & Engineering   Department of Mechanical & Industrial Engineering

Samin Aref, Ph.D.
Affiliation: Department of Mechanical & Industrial Engineering, University of Toronto
Office: BA8112, Level 8, Bahen Centre for Information Technology, 40 St George St, Toronto (map)
Phone: (+1) 416-946-7233
Email: aref[at]mie[dot]utoronto[dot]ca
Mailing Address: MIE Department, 5 King’s College Road, Toronto, Ontario, M5S 3G8, Canada


I am a researcher and educator working as an assistant professor, teaching stream in data science at the University of Toronto Department of Mechanical & Industrial Engineering. My areas of interest are Machine Learning, Operations Research, Network Science, Human-Centred AI, Industrial Engineering, Data Science, and Computational Social Science. My current research falls into three broad topics: (1) analyzing complex social and informational systems using networks and mathematical models; (2) modeling planning and decision problems in uncertain environments using mathematical programming and efficient algorithms; (3) studying the science of science across disciplines and geographies using large-scale digital trace data. I have an Erdős number of 3 and I have worked in most continents!

Current Projects:

Algorithms and Models for the Computational Analysis of the Structure and Dynamics in Complex Networks
This project is at the intersection of network science and operations research and involves developing mathematical models and efficient algorithms for analyzing the structure of large-scale networks. In particular, I have contributed to the fundamental mathematics of formulating graph optimization models to analyze community structure and polarization in networks (an 8-minute presentation).
Measuring balance
Computing frustration index
Frustration index of large networks
Applications of frustration and partitioning
Partitioning networks of US Congress legislators
Multilevel evaluation of balance
Splinter coalitions of the US Congress
Modularity-based heuristics
Analyzing modularity maximization
The Bayan algorithm (pip install bayanpy)

Modeling Planning and Decision Problems in Uncertain Environments Using Mathematical Programming and Efficient Optimization Algorithms
This project is centered at combining knowledge from operations research, computer science, and statistics to develop realistic computational models for planning and decision problems and solving them for practical applications in engineering, business, and management.
Hotel customer relationship management
Green vehicle routing
Concurrent product development
Scheduling flexible manufacturing systems
Logistics network design
Supply chain bottlenecks
Diversity allocation in could computing

Studying the Science of Science Across Disciplines and Geographies Using Large-scale Digital Trace Data
In another series of studies, I led a 3-year project on repurposing large-scale bibliometric data for studying the mechanisms underlying the doing of science including career trajectories, migration, and collaborations in academia at the level of individuals, organizations, disciplines, and nations.
Map of New Zealand scientific collaborations
New data sources for population research
Analysis of super-mover researchers
Internal migration of scholars in Mexico
Brain drain in Russia
Scholarly migration in Germany
Return migration in academia
Homecoming after Brexit
Scholarly migration database


Ph.D. in Computer Science, The University of Auckland (UoA)
-Thesis on Signed Network Structural Analysis and Applications, supervised by Dr. Mark C. Wilson and Dr. Andrew J. Mason (examiners: Prof. Gregory Gutin and Dr. Serge Gaspers)

M.Sc. in Industrial Engineering (operations research), Sharif University of Technology
-Thesis on Network Air Cargo Revenue Management, supervised by Prof. Mohammad Modarres (examiners: Prof. Abdol Hamid Eshragh and Dr. Mahsa Ghandehari)

B.Sc. in Industrial Engineering (manufacturing), Iran University of Science and Technology
-Project on Movie Industry Integrated Scheduling Methodology, supervised by Dr. Morteza Bagherpour (examiners: Prof. Ahmad Makui and Dr. Roozbeh Ghousi)


Graduate courses:
APS1070: Foundations of Data Analytics and Machine Learning (Faculty of Applied Science and Engineering, U of T)
BAIT509: Business Applications of Machine Learning (Sauder School of Business, University of British Columbia)
MIE1626: Data Science Methods and Statistical Learning (Department of Mechanical and Industrial Engineering, U of T)
A series of recorded lectures and Python labs from my two graduate courses (MIE1626 and BAIT509) is publicly available on YouTube:

Undergraduate courses:
MIE258 (MIE358): Engineering Economics and Accounting (Department of Mechanical and Industrial Engineering, U of T)
MIE498 : Undergraduate Research Thesis (Department of Mechanical and Industrial Engineering, U of T)
CSC494 : Computer Science Project (Department of Computer Science, U of T)

Supervision and Mentorship:

Prospective research students:
I am not currently recruiting PhD or other graduate students from outside of the University of Toronto. Whenever this changes, this paragraph will be replaced with the details of the position that I will be recruiting for. Unfortunately, I cannot respond to all emails from prospective students. If you have emailed me as a prospective PhD/MASc applicant and have not received a response in a week, it is safe to assume that I do not have any available/potential positions for you. Good luck with your search.

Current and previous research students:
Boris Ng: Formerly, undergraduate research student, Department of Mechanical and Industrial Engineering, University of Toronto
Sanchaai Mathiyarasan: Formerly, undergraduate research student, Department of Computer Science, University of Toronto
Hriday Chheda: Formerly, undergraduate research student, Department of Computer Science, University of Toronto (paper) (preprint)
Qingyang (Ida) Yu: Formerly, Master of Science in Applied Computing (MSCAC) student, Department of Computer Science, University of Toronto
Xinyi Zhao: PhD student at the University of Oxford and the MPIDR (paper 1) (paper 2)
Ebru Sanliturk: Formerly, PhD candidate at Bocconi University and visiting PhD student at the MPIDR (working paper)
Alexander Subbotin: Formerly, PhD student at Lomonosov Moscow State University and the European Doctoral School in Demography (paper)
Andrea Miranda-González: Formerly, PhD student at UC Berkeley and visiting PhD student at the MPIDR (paper)

Publications and Preprints:

Analyzing modularity maximization in approximation, heuristic, and graph neural network algorithms for community detection (with Mahdi Mostajabdaveh)
Journal of Computational Science
Full text> Author copy> Data>

The Bayan algorithm: detecting communities in networks through exact and approximate optimization of modularity (with Hriday Chheda and Mahdi Mostajabdaveh)
Author copy> Website> Repository> Data> CDlib> Python package>

Homecoming after Brexit: evidence on academic migration from bibliometric data (with Ebru Sanliturk, Emilio Zagheni, and Francesco C. Billari)
Author copy> Data>

Heuristic modularity maximization algorithms for community detection rarely return an optimal partition or anything similar (with Mahdi Mostajabdaveh and Hriday Chheda)
Proceedings of the 23rd International Conference on Computational Science (ICCS 2023)
Full text> Author copy>

Dynamic rescheduling in flexible manufacturing systems under disruptions (with Maryam Rahimi, Reza Tavakkoli-Moghaddam, and Amir Azaron)

Modeling and analysis of security and economic metrics for moving target defense techniques in cloud computing (with Hooman Alavizadeh, Dong Seong Kim, and Julian Jang-Jaccard)
IEEE Transactions on Emerging Topics in Computing
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Return migration of German-affiliated researchers: Analyzing departure and return by gender, cohort, and discipline using Scopus bibliometric data 1996-2020 (with Xinyi Zhao, Emilio Zagheni, and Guy Stecklov)
Full text> Author copy> Data> Press release>

Identifying hidden coalitions in the US House of Representatives by optimally partitioning signed networks based on generalized balance (with Zachary P. Neal)
Scientific Reports
Full text> Author copy> Data> Code> Recorded talk>

International migration in academia and citation performance: An analysis of German-affiliated researchers by gender and discipline using Scopus publications 1996-2020 (with Xinyi Zhao, Emilio Zagheni, and Guy Stecklov)
Proceedings of the 18th International Conference on Scientometrics and Informetrics (ISSI 2021)
Full text> Author copy> Press release>

Brain drain and brain gain in Russia: Analyzing international mobility of researchers by discipline using Scopus bibliometric data 1996-2020 (with Alexander Subbotin)
Full text> Author copy> Poster> Recorded talk> Interview>

Multilevel structural evaluation of signed directed social networks based on balance theory (with Ly Dinh, Rezvaneh Rezapour, and Jana Diesner)
Scientific Reports
Full text> Author copy> Data> Code> Recorded talk>

Detecting coalitions by optimally partitioning signed networks of political collaboration (with Zachary P. Neal)
Scientific Reports
Full text> Author copy> Data> Poster> Code> Press release>

Scholarly migration within Mexico: Analyzing internal migration among researchers using Scopus longitudinal bibliometric data (with Andrea Miranda-González, Tom Theile, and Emilio Zagheni)
EPJ Data Science
Full text> Author copy> Data> Poster> Press release>

A modeling and computational study of the frustration index in signed networks (with Andrew Mason and Mark Wilson)
Networks (Old title: An Exact Method for Computing the Frustration Index in Signed Networks Using Binary Programming)
Full text> Author copy> Recorded talk> Slides> Code>

The demography of the peripatetic researcher: Evidence on highly mobile scholars from the Web of Science (with Emilio Zagheni and Jevin West)
Lecture Notes in Computer Science (Proceedings of the 11th International Conference on Social Informatics)
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Demography in the digital era: New data sources for population research (with Diego Alburez-Gutierrez, Sofia Gil-Clavel, Andre Grow, Daniela Negraia, and Emilio Zagheni)
Book of Short Papers SIS2019 (Società italiana di statistica)
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Signed network structural analysis and applications with a focus on balance theory
Doctoral dissertation, The University of Auckland
Full text> Author copy>

Balance and frustration in signed networks (with Mark Wilson)
Journal of Complex Networks
Full text> Author copy> Data> Poster (CCS'18 best poster)> Dynamic visualization> Code>

Analysing scientific collaborations of New Zealand institutions using Scopus bibliometric data (with David Friggens and Shaun Hendy)
Proceedings of Australasian Computer Science Week 2018
Full text> Author copy> Poster (174 MB)> Data>

Computing the line index of balance using integer programming optimisation (with Andrew Mason and Mark Wilson)
Optimization Problems in Graph Theory
Full text> Author copy> Slides> Code>

A green perspective on capacitated time-dependent vehicle routing problem with time windows (with Iman Kazemian)
International Journal of Supply Chain and Inventory Management
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Measuring partial balance in signed networks (with Mark Wilson)
Journal of Complex Networks
Full text> Author copy> Slides> Poster (NZMS'15 best poster runner-up)>

Hub location under uncertainty: A minimax regret model for the capacitated problem with multiple allocations (with Iman Kazemian)
International Journal of Supply Chain and Inventory Management
Full text> Author copy> Slides>

Multi-echelon supply chain flexibility enhancement through detecting bottlenecks (with Iman Kazemian)
Global Journal of Flexible Systems Management
Full text> Author copy> Slides>

The use of a GERT based method to model concurrent product development processes (with Richard Nelson and Amir Azaron)
European Journal of Operational Research
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Developing an integrated revenue management and customer relationship management approach in hotel industry (with Amirhossein Vaeztehrani and Mohammad Modarres)
Journal of Revenue & Pricing Management
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Epidemiological and biomechanical evaluation of airline baggage handling (with Alireza Tafazzol, Majid Mardani, Omid Haddad, and Mohammad Parnianpour)
International Journal of Occupational Safety and Ergonomics
Full text> Author copy>

Research Grants:

Role: Principal investigator
Project title: Personal and professional factors driving academics to move to and from Canada
Project members and collaborators: Guy Stecklov
Funding body: Social Sciences and Humanities Research Council (SSHRC), Canada

Role: Principal investigator
Project title: Analyzing the migration of researchers to and from Germany during 1996-2020 and evaluating its interplay with fields of scholarship, level of experience, gender, and research performance
Project members and collaborators: Xinyi Zhao, Emilio Zagheni, Guy Stecklov, and Kathrin McCann
Funding body: The Federal Ministry of Education and Research (BMBF) via the German Academic Exchange Service (DAAD), Germany

Popular Press, Policy Features, and Science Communications:

- Policy debate based on the findings of our research - German Parliament Records (May 2023) [in German]
- Is AI coming for your job? These are the workers who will be replaced first, according to experts - Toronto Star (May 2023)
- Russian scientists snub Johnson’s offer to defect to UK - Research Professional News (Sep. 2022)
- Brexit vote did not increase brain drain from the UK, study finds - Research Professional News (Aug. 2022)
- Will we ever see them again? - Population Europe (Jul. 2022)
- Science hub - Emigration and immigration of researchers: negative results for Germany - Demografische Forschung Aus Erster Hand (Sep. 2021) [in German]
- Russian brain drain eases but emigrants still most highly cited - Times Higher Education (Sep. 2021)
- It’s too early to shout out loud that Russia is an attractive country for scientists - Indicator (Sep. 2020) [in Russian]
- Perceptions of possible co-benefits - views on the intersection between the climate crisis and the COVID-19 pandemic - Nature Behavioral & Social Sciences (Apr. 2020)
- Polarization helps Congress pass bills - MSU Today (Jan. 2020)
- Does a polarized US Congress get more done? - Futurity (Jan. 2020)

Conference Presentations and Invited Talks:

2024 (in-person): NetSci'24 (Quebec city), keynote talk at ETH Zurich (Zurich), invited talk the Modelling and Mining Complex Networks as Hypergraphs (Toronto), invited talk at the Schwartz Reisman Institute Research Exchange (Toronto)

2023 (in-person and virtual): IC2S2'23 (Copenhagen), SINM at NetSci'23 (Vienna), ComNets at NetSci'23 (Vienna), CORS'23 (Montreal), WAW'23 (Toronto), Invited lecture and invited talk at the MPIDR (Rostock), CompleNet'23 (Aveiro), invited lecture at the University of South Florida, invited talk at the UBC OpLog Seminar (Vancouver), invited talk at the UBC Industrial Engineering Research Group (Vancouver)

2022 (in-person and virtual): Invited talk at the DeGroote School of Business (Hamilton), invited talk at CORA, National Defence (Ottawa), invited talk at the NetSci'22 satellite on signed networks (Shanghai), INFORMS-CORS'22 (Vancouver), invited talk at the 2nd Conference on Mathematics and Politics, invited talk at the German Academic Exchange Service, invited lecture at Mississippi State University, invited talk at Oxford Brookes University, invited talk at Sharif University

2021 (all virtual): CSS@CCS'21 (Lyon), EUSN'21 (Naples), PaCSS'21, IC2S2'21 (Zurich), ISSI'21 (Leuven), Networks'21 (Washington DC), PolNet'21 (Pennsylvania), invited talk at the Leibniz Institute for East and Southeast European Studies, WWW'21 (Ljubljana), NERCCS'21, invited talk at ANZAMP Seminar (Melbourne), invited talk at Higher School of Economics, NASN'21

2020 (all virtual): CCS'20 (Mallorca), invited lecture at Higher School of Economics, invited talk at the Center for Institutional Studies, SocInfo'20 (Pisa), invited talk at the Consortium on Analytics for Data-Driven Decision-Making, invited talk at Michigan State University, NetSci'20 (Rome), PolNet'20 (Massachusetts), Sunbelt'20 (Paris), MGGG Networks Workshop (Massachusetts), SIAM-NS'20 (Toronto), invited talk at the German Academic Exchange Service (Bonn)

2019 (in-person): Complex Networks'19 (Lisbon), invited talk at PACE (Paderborn), SocInfo'19 (Doha), invited talk at CCNSD (Tehran), EUSN'19 (Zurich), EuroCSS'19 (Zurich), IC2S2'19 (Amsterdam), Sunbelt'19 (Montreal), IUSSP workshop (Seville), CompleNet'19 (Tarragona), ECSR workshop (Milan), invited talk at Groupe Réseaux (Montreal), invited talk at Institute WeST (Koblenz)

2018 (in-person): EuroCSS'18 (Cologne), Digital Demography Symposium (Rostock), CCS'18 (Thessaloniki), Sunbelt'18 (Utrecht), ACSW'18 (Brisbane)

2017 (in-person): IASC'17 (Auckland), ORSNZ'17 (Auckland), NZMS'17 (Auckland), AUTMS'17 (Auckland), Sunbelt'17 (Beijing)

2016 (in-person): NZMS'16 (Wellington), ORSNZ'16 (Auckland), CMSS'16 (Auckland), NetSci-X'16 (Wroclaw)

2015 (in-person): NZMS'15 (Christchurch), CMSS'15 (Auckland)

Academic Service to the Discipline:

Python workshop on networks (co-organized with Shadi Rezapour, Ly Dinh, and Jana Diesner)
July 2022 (at Sunbelt'22 - Cairns), July 2021 (at IC2S2'21 - Zurich), June 2021 (at Networks'21 - Washington DC), April 2021 (at WWW'21 - Ljubljana)

Introduction to Machine Learning and Predictive Modeling
Workshop on ML fundamentals for general academic audience
May 2023 (at MPIDR - Rostock), July 2022 (at Sunbelt'22 - Cairns), June 2022 (at ICWSM'22 - Atlanta)

Negative Ties and Signed Graphs
Special track of the INSNA Sunbelt Conference (co-organized with Filip Agneessens, Ernesto Estrada, Nicholas Harrigan, Joe Labianca, Zachary Neal, and Andreia Sofia Teixeira)
July 2022 (at Sunbelt'22 - Cairns), July 2021 (at Networks'21 - Washington DC), July 2020 (at Sunbelt'20 - Paris), June 2019 (at Sunbelt'19 - Montreal)

The second international workshop on MIgration and MObility research in the Digital Era (co-organized with Daniela Perrotta and Jisu Kim)
October 2021 in Lyon, France and virtual

Social Informatics 2020
October 2020 in Pisa, Italy and virtual

Social Informatics 2019
November 2019 in Doha, Qatar

Professional Memberships and Affiliations:

Schwartz Reisman Institute for Technology and Society - SRI (faculty affiliate)
Centre for Analytics and Artificial Intelligence Engineering - CARTE (faculty affiliate)
University of Toronto, School of Cities (faculty affiliate)
Institute for Mathematics and Democracy (faculty affiliate)
Network Science Society
Complex Systems Society
Institute for Operations Research and the Management Sciences (INFORMS)
American Society for Engineering Education
Society for Industrial and Applied Mathematics
International Network for Social Network Analysis
Max Planck PostdocNet
Operations Research Society of New Zealand
New Zealand Mathematical Society
Centre for Mathematical Social Science
Max Planck Alumni Association
Australian and New Zealand Association of Mathematical Physics

Other Profiles:

University of Toronto MPIDR LinkedIn ResearchGate Google Scholar ArXiv ORCID dblp Scopus GitHub FigShare Twitter Mastodon