Samin Aref

Samin Aref
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Samin verified their affiliation via an institutional email.
Verified
Samin verified their affiliation via an institutional email.
University of Toronto | U of T · Department of Mechanical and Industrial Engineering

Computer Science (Ph.D.)
Data Science, Operations Research, Machine Learning, Network Science, Business Analytics, and Operations Management

About

41
Publications
27,885
Reads
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625
Citations
Introduction
I am an assistant professor, teaching stream in data science at the University of Toronto. 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.
Additional affiliations
October 2018 - July 2022
Max Planck Institute for Demographic Research
Position
  • Research Scientist and Research Area Chair
February 2018 - June 2018
Callaghan Innovation
Position
  • Analyst
December 2016 - March 2017
Ministry of Business, Innovation and Employment, New Zealand
Position
  • Analyst
Education
February 2015 - December 2018
University of Auckland
Field of study
  • Computer Science
September 2012 - March 2014
Sharif University of Technology
Field of study
  • Industrial Engineering (Operations Research)
September 2008 - September 2012
Iran University of Science and Technology
Field of study
  • Industrial Engineering (Manufacturing)

Publications

Publications (41)
Article
Full-text available
Computing the frustration index of a signed graph is a key step toward solving problems in many fields including social networks, political science, physics, chemistry, and biology. The frustration index determines the distance of a network from a state of total structural balance. Although the definition of the frustration index goes back to the 1...
Article
Full-text available
In network science, identifying optimal partitions of a signed network into internally cohesive and mutually divisive clusters based on generalized balance theory is computationally challenging. We reformulate and generalize two binary linear programming models that tackle this challenge, demonstrating their practicality by applying them them to pa...
Article
Full-text available
The international migration of researchers is an important dimension of scientific mobility, and has been the subject of considerable policy debate. However, tracking the migration life courses of researchers is challenging due to data limitations. In this study, we use Scopus bibliometric data on eight million publications from 1.1 million researc...
Preprint
Full-text available
Community detection is a classic network problem with extensive applications in various fields. Its most common method is using modularity maximization heuristics which rarely return an optimal partition or anything similar. Partitions with globally optimal modularity are difficult to compute, and therefore have been underexplored. Using structural...
Conference Paper
Full-text available
Community detection is a fundamental problem in computational sciences with extensive applications in various fields. The most commonly used methods are the algorithms designed to maximize modularity over different partitions of the network nodes. Using 80 real and random networks from a wide range of contexts, we investigate the extent to which cu...
Article
Full-text available
Non-homologous chromosomal contacts (NHCCs) between different chromosomes participate considerably in gene and genome regulation. Due to analytical challenges, NHCCs are currently considered as singular, stochastic events, and their extent and fundamental principles across cell types remain controversial. We develop a supervised and unsupervised le...
Article
Full-text available
Community detection, which involves partitioning nodes within a network, has widespread applications across computational sciences. Modularity-based algorithms identify communities by attempting to maximize the modularity function across network node partitions. Our study assesses the performance of various modularity-based algorithms in obtaining...
Preprint
Full-text available
Community detection is a fundamental problem in computational sciences with extensive applications in various fields. The most commonly used methods are the algorithms designed to maximize modularity over different partitions of the network nodes. Using 80 real and random networks from a wide range of contexts, we investigate the extent to which cu...
Article
Full-text available
Moving Target Defense (MTD) is a proactive security mechanism that changes the attack surface with the aim of confusing attackers. Cloud computing leverages MTD techniques to enhance the cloud security posture against cyber threats. While many MTD techniques have been applied to cloud computing, there has so far been no joint evaluation of the effe...
Preprint
Full-text available
This study assesses the initial effects of the 2016 Brexit referendum on the mobility of academic scholars to and from the United Kingdom (UK). We leverage bibliometric data from millions of Scopus publications to infer changes in the countries of residence of published researchers by the changes in their institutional affiliations over time. We fo...
Preprint
Full-text available
The international migration of researchers is an important dimension of scientific mobility, and has been the subject of considerable policy debate. However, tracking the migration life courses of researchers is challenging due to data limitations. In this study, we use Scopus bibliometric data on eight million publications from 1.1 million researc...
Article
Full-text available
We study international mobility in academia, with a focus on the migration of published researchers to and from Russia. Using an exhaustive set of over 2.4 million Scopus publications, we analyze all researchers who have published with a Russian affiliation address in Scopus-indexed sources in 1996–2020. The migration of researchers is observed thr...
Preprint
Full-text available
We study international mobility in academia, with a focus on the migration of published researchers to and from Russia. Using an exhaustive set of over 2.4 million Scopus publications, we analyze all researchers who have published with a Russian affiliation address in Scopus-indexed sources in 1996-2020. The migration of researchers is observed thr...
Preprint
Full-text available
Germany has become a major country of immigration, as well as a research powerhouse in Europe. As Germany spends a higher fraction of its GDP on research and development than most countries with advanced economies, there is an expectation that Germany should be able to attract and retain international scholars who have high citation performance. Us...
Conference Paper
Full-text available
Germany has become a major country of immigration, as well as a research powerhouse in Europe. As Germany spends a higher fraction of its GDP on research and development than most countries with advanced economies, there is an expectation that Germany should be able to attract and retain international scholars who have high citation performance. Us...
Article
Full-text available
The migration of scholars is a major driver of innovation and of diffusion of knowledge. Although large-scale bibliometric data have been used to measure international migration of scholars, our understanding of internal migration among researchers is very limited. This is partly due to a lack of data aggregated at a suitable sub-national level. In...
Article
Full-text available
Balance theory explains how network structural configurations relate to tension in social systems, which are commonly modeled as static undirected signed graphs. We expand this modeling approach by incorporating directionality of edges and considering three levels of analysis for balance assessment: triads, subgroups, and the whole network. For tri...
Preprint
Full-text available
Moving Target Defense (MTD) is a proactive security mechanism which changes the attack surface aiming to confuse attackers. Cloud computing leverages MTD techniques to enhance cloud security posture against cyber threats. While many MTD techniques have been applied to cloud computing, there has not been a joint evaluation of the effectiveness of MT...
Preprint
Full-text available
Balance theory explains the forces behind the structure of social systems, which are commonly modeled as static undirected signed networks. We expand this modeling approach to incorporate directionality of edges, and consider three levels of analysis: triads, subgroups, and the whole network. For triad-level balance, we operationalize a new measure...
Preprint
Full-text available
Migration of scholars is a major driver of innovation and diffusion of knowledge. Although large-scale bibliometric data have been used to measure international migration of scholars, our understanding of internal migration among researchers is very limited. This is partly due to lack of data aggregated at a suitable sub-national level. In this stu...
Article
Full-text available
We propose new mathematical programming models for optimal partitioning of a signed graph into cohesive groups. To demonstrate the approach's utility, we apply it to identify coalitions in US Congress since 1979 and examine the impact of polarized coalitions on the effectiveness of passing bills. Our models produce a globally optimal solution to th...
Chapter
Full-text available
The policy debate around researchers' geographic mobility has been moving away from a theorized zero-sum game in which countries can be winners ("brain gain") or losers ("brain drain"), and toward the concept of "brain circulation," which implies that researchers move in and out of countries and everyone benefits. Quantifying trends in researchers'...
Preprint
Full-text available
The spread of digital technologies and the increased access to the internet has contributed to the production and accumulation of unprecedented quantities of data about human behavior. Demographers, who have a long-standing interest in issues related to data and data quality, are in an ideal position to make sense of this new information. This pape...
Article
Full-text available
The frustration index is a key measure for analysing signed networks, which has been underused due to its computational complexity. We use an exact optimisation-based method to analyse frustration as a global structural property of signed networks coming from diverse application areas. In the classic friend-enemy interpretation of balance theory, a...
Thesis
Full-text available
This research is an effort to understand small-scale properties of networks resulting in global structure in larger scales. Networks are modelled by graphs and graph-theoretic conditions are used to determine the structural properties exhibited by the network. Our focus is on signed networks which have positive and negative signs as a property on t...
Article
In production processes of a flexible manufacturing system (FMS), unexpected disruptions like new parts arrival and machine failure may make the existing schedule substantially inefficient. Dynamic rescheduling is required to respond to such disruptions in order to improve the efficiency of the disturbed FMS. This paper presents a particle swarm op...
Article
Full-text available
An important measure of a signed graph is the line index of balance which has several applications in many fields. However, this graphtheoretic measure was underused for decades because of the inherent complexity in its computation which is closely related to NP-hard graph optimisation problems like MAXCUT. We develop new quadratic and linear progr...
Article
Full-text available
Is the enemy of an enemy necessarily a friend? If not, to what extent does this tend to hold? Such questions were formulated in terms of signed (social) networks and necessary and sufficient conditions for a network to be ``balanced" were obtained around 1960. Since then the idea that signed networks tend over time to become more balanced has been...
Conference Paper
Full-text available
Scientific collaborations are among the main enablers of development in small national science systems. Although analysing scientific collaborations is a well-established subject in scientometrics, evaluations of scientific collaborations within a country remain speculative with studies based on a limited number of fields or using data too inadequa...
Data
This dataset contains major outputs of a study on collaboration links between all New Zealand universities based on Scopus publications within 2010-2015. For more details about the study, one may refer to Samin Aref, David Friggens, and Shaun Hendy. 2018. Analysing Scientific Collaborations of New Zealand Institutions using Scopus Bibliometric Data...
Data
This dataset contains a wide range of signed networks from different disciplines. For more information about the data, one may refer to the paper below: Samin Aref "Balance and Frustration in Signed Networks under Different Contexts" (2017) ArXiv Preprint, arxiv.org/abs/1712.04628 Dataset reference: Aref, Samin (2017): Signed networks from sociol...
Preprint
An important measure of signed graphs is the line index of balance which has several applications in many fields. However, this graph-theoretic measure was underused for decades because of the inherent complexity in its computation which is closely related to solving NP-hard graph optimisation problems like MAXCUT. We develop new quadratic and line...
Preprint
Scientific collaborations are among the main enablers of development in small national science systems. Although analysing scientific collaborations is a well-established subject in scientometrics, evaluations of scientific collaborations within a country remain speculative with studies based on a limited number of fields or using data too inadequa...
Article
Full-text available
In this paper the capacitated hub location problem is formulated by a minimax regret model, which takes into account uncertain setup cost and demand. We focus on capacitated hub location with multiple allocations as a strategic problem requiring one definite solution. Investigating how deterministic models may lead to sub-optimal solutions, we prov...
Article
Full-text available
This study presents a novel approach to the vehicle routing problem by focusing on greenhouse gas emissions and fuel consumption aiming to mitigate adverse environmental effects of transportation. A time-dependent model with time windows is developed to incorporate speed and schedule in transportation. The model considers speed limits for different...
Preprint
Computing the frustration index of a signed graph is a key step toward solving problems in many fields including social networks, political science, physics, chemistry, and biology. The frustration index determines the distance of a network from a state of total structural balance. Although the definition of the frustration index goes back to the 1...
Article
Full-text available
This study suggests a supply chain design deploying a novel idea from production planning. The idea of capacity bottlenecks is used to improve flexibility in a multi-echelon multi-product supply chain. We suggest an optimization model that focuses on optimal capacity allocations to bottleneck points in order to enhance overall flexibility. The prop...
Article
Full-text available
This paper proposes a time-computing model using the Graphical Evaluation and Review Technique (GERT) to analyse concurrent New Product Development (NPD) processes. The research presented here differs from previous work carried out on concurrent engineering. First, we conceptualise a concurrent NPD process using the GERT scheduling technique and de...
Article
Full-text available
Objectives: Musculoskeletal disorders (MSDs) are prevalent among airline baggage handlers due to manual materials handling. In this study, the Nordic musculoskeletal questionnaire (NMQ), the revised NIOSH (National Institute for Occupational Safety and Health) lifting equation, and the University of Michigan 3D Static Strength Prediction Program(T...
Article
Full-text available
Revenue management (RM) and customer relationship management (CRM) are the standard strategies of many hotels to increase their profitability. Although the objectives and time horizons of RM and CRM are different, they can be considered as complimentary business strategies. However, the integration has received little attention both practically and...

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