Networks, Data, and Society (NERDS)

Talk Anastassia Vybornova at CRBAM21
2021-10-15 10:00 - 10:15 (Europe/Copenhagen) | IDA CONFERENCE, Kalvebod Brygge 31-33, Copenhagen, 1780, Denmark
Network algorithms for the identification and classification of gaps in urban bicycle networks based on OSM data
What is the best location to build new bicycle infrastructure in a city? This planning decision can be conceptualized as an optimization problem: the goal is to find the most efficient solution – that is, the one that has the highest (positive) impact on the bicycle network at least cost. However, identifying locations that will significantly improve network quality is far from being a straightforward task. The first challenge is to put a number on network quality improvement in order to make different planning decisions comparable; the second is the often cumbersome collection and processing of data required by the chosen approach (e.g. input from large-scale user surveys).
Our data-driven, computational approach for the identification of gaps in bicycle networks simultaneously addresses both these challenges. We present an algorithm that identifies and rates (by relevance) gaps in a bicycle network, based solely on the input of topological features which are readily available as open-source data from OSM (OpenStreetMap). For this purpose, we define “gaps” as segments (of flexible maximum length) of existing streets which, if provided with a bicycle facility, improve the overall quality of the network. We assess the quality of the network based on network connectivity measures from graph theory, in particular edge betweenness centrality. We furthermore assume that cyclists prefer to use protected bicycle infrastructure and are willing to take a certain detour to maximize the percentage of route spent on bicycle facilities.
To showcase the applicability of our approach, we present the gaps identified by the algorithm in the bicycle network of Copenhagen, classified and ranked by relevance (quality impact). We compare our results with the city’s current bicycle network development plan (Cykelsti Prioriteringsplan 2017-2025) to assess the validity of our findings. Our work shows how network analysis based on open-source topological data can serve as a powerful and cost-efficient tool for decision-making support in bicycle network planning.

Talk Bojan Kostic at CRBAM21
2021-10-14 15:30 - 15:45 (Europe/Copenhagen) | IDA CONFERENCE, Kalvebod Brygge 31-33, Copenhagen, 1780, Denmark
Analysing cyclist behavior at signalized intersections using computer vision
Artificial intelligence, in particular deep learning and computer vision, is a promising new tool for automated video analysis in traffic studies. It allows for facilitated extraction of detailed data from video recordings at higher efficiency and lower costs, improved precision of obtained data, and reduced errors caused by manual video elaboration. This method has the potential to answer detailed questions on human traffic behavior which were very difficult, if not impossible, to answer previously. In this work we use such AI tools to investigate cyclist behavior at signalized intersections. We approach the problem by utilizing state-of-the-art tools for automated video analysis and apply them to detect and track road users in video recordings (cyclists, vehicles, and pedestrians) and extract their travelled trajectories. This gives us a fine-grained spatio-temporal data set of cyclist movements in the present of vehicles, pedestrians, and traffic lights regulation throughout the day. We perform clustering of the trajectories to identify various patterns of movements from different origins to destinations, and analyze their desire lines. This data set also allows for an insightful intersection safety analysis through assessing conflicts and surrogate measures of safety. We further investigate the social factor on cyclist behaviour, such as individual versus group behaviour in obeying the rules. We recorded a busy intersection in Copenhagen, Denmark for over 12 hours and recovered several thousand cyclist trajectories, uncovering insights about cyclist behaviour and factors affecting it. These results can be used in better and more efficient planning and operation of intersections with cyclist, to improve safety by better identifying critical conflict points, inadequate bicycle infrastructure, and situations at which regulations are not followed that may cause confusion and risky behaviour.

Roberta gives a seminar for Reykjavik University and the Gran Sasso Science
2021-09-22 15:00 - 16:00 (Europe/Copenhagen)
TITLE:
Quantifying biases in science

ABSTRACT:
Every day our life is made easier by efficient measures and algorithms that search and rank scientific information. Yet, these algorithms have an issue: they are trained on citations, which are ingrained with human biases. Therefore the output is inherently biased too, creating inequalities, raising concerns of discrimination, even harming economic growth. I will present research focusing on quantifying bias in publication data. The overarching goal of this research is to uncover the mathematical bias mechanisms that, given the same quality, drive different citation trajectories, and use them to create fair algorithms.

NERDS Seminar with Helge Pfeiffer
2021-09-22 12:30 - 13:30 (Europe/Copenhagen) | 2F12, Kaj Munks Vej 11, Copenhagen, 2300, Denmark
The NERDS seminar continues Wednesday (22/09/2021) with an exciting talk by Helge Pfeiffer, Assistant Professor at ITU, titled: “Everything is Connected – Leveraging Graphs in Software Engineering Research”. Please join us from 12:30-13:30 in person at EHK-2F12 (or via Zoom – regular link – for virtual attendance). The presentation abstract and presenter’s bio are below. I hope you can all make it!
Abstract
In my talk, I will present an overview over my students’ and my recent work on various aspects of software engineering, e.g., identification of critical projects in software ecosystems, license compatibility, or software reuse. In all of which, we leverage graph representations of software artefacts.
I will briefly outline current and future work and sketch challenges ranging from data availability to efficient graph representation, computation, and visualisation methods and tools.
With the latter, I would like to gather your feedback, experiences, and would like to learn from you, since you are the network experts at ITU and I am more a “standard software engineer that remembers som graph theory and likes graphs in general” :).
Also, I would like to identify areas of potential mutual interest on possible future collaborations.
Bio
Helge Pfeiffer works an assistant professor at the IT University of Copenhagen in the Research Center for Government IT. His research interests are in the areas of software engineering, software quality, software quality metrics, and technical debt. Before joining the Research Center for Government IT, he was working as software engineer for the Danish Meteorological Institute and as adjunkt at CPH Business Academy. In the former he was responsible for development and maintenance of 24/7 remote sensing applications and in the latter, he was teaching all aspects of software engineering.

ITU KSD/KCS Research Project Market
2021-09-01 16:00 - 18:00 (Europe/Copenhagen) | Aud 1, Rued Langgaards Vej 7, Copenhagen, 2300, Denmark
Project Market for Research Projects for K-CS and K-SD students at ITU

NERDS Seminar: Luca Aiello
2021-03-03 12:30 - 13:30 (Europe/Copenhagen) | Zoom NERDS
Luca Aiello, ITU (NERDS): Towards Health Surveillance with Social Media

In today’s heavily interconnected world, health crises develop rapidly and spread afar. Health crises burden not only people’s biological health but also their psychological and social spheres. By monitoring the population’s behavior and health conditions, public health bodies can plan prevention campaigns, promptly deploy targeted interventions, and adapt to people’s responses. We contributed to this stream of research by developing a Deep Learning tool for Natural Language Processing that extracts mentions of virtually any medical condition from unstructured social media text. We applied the tool to Reddit and Twitter posts, analyzed the clusters of the two resulting co-occurrence networks of conditions, and discovered that they correspond to well-defined categories of medical conditions. This resulted in the creation of a taxonomy of medical conditions automatically derived from online discussions. We validated the structure of our taxonomy against the official International Statistical Classification of Diseases and Related Health Problems (ICD-11), finding matches of our clusters with 20 official categories, out of 22. Based on the mentions of our taxonomy’s sub-categories on Reddit posts geo-referenced in the U.S., we were then able to compute disease-specific health scores which correlate with officially reported prevalences of 18 conditions.

Roberta @ UniCT for International Day of Women and Girls in Science
2021-02-11 15:00 - 17:00 (Europe/Copenhagen)
(Event in Italian)
Giovedì 11 febbraio 2021, con inizio alle ore 15:00, in occasione dell’International Day of Women and Girls in Science, il Dipartimento di Fisica e Astronomia “Ettore Majorana”, in collaborazione con il Centro Siciliano di Fisica Nucleare e Struttura della Materia #CSFNSM, ospiterà (online) l’incontro con due scienziate per esplorare percorsi di donne nella Fisica.
Ospiti dell’incontro saranno l’astrofisica Dr Simonetta Di Pippo, direttrice del United Nations Office for Outer Space Affairs #UNOOSA, e la Dr Roberta Sinatra, ricercatrice della IT University of Copenhagen, ex Allieva del DFA e Alumna della Scuola Superiore di Catania.
Interverranno la Prof.ssa Adriana Di Stefano, Delegata del Rettore dell’Università degli Studi di Catania #UniCT alle Pari Opportunità e la Prof.ssa Alessia Tricomi, Delegata del Rettore UniCT alla Terza Missione e Direttrice del #CSFNSM.
Sarà possibile assistere live all’incontro sulla pagina Facebook del #CSFNSM e sul canale YouTube del #DFA al link https://www.youtube.com/watch?v=tNA6K8NNZSI

Roberta @ Niels Bohr Institute
2021-01-29 15:00 - 16:00 (Europe/Copenhagen)
Quantifying the dynamics of impact in science and art (Remote Colloquium)

Roberta @ DTU Compute
2021-01-12 14:45 - 16:15 (Europe/Copenhagen)

Roberta @ The Asian Institute of Management
2020-11-26 18:00 - 19:30 (Asia/Manila)

Invited talk Maksim Kitsak
2020-10-30 12:15 - 13:15 (Europe/Copenhagen)
Maksim Kitsak (Delft University of Technology)
Geometric Representations of Complementarity-Driven Networks
Abstract:

Complementarity-driven networks are routinely embedded into latent metric spaces with the purpose of data analysis. We argue that these traditional geometric representations, where connected nodes are embedded close to each other in the latent space, are not applicable to complementarity-driven networks due to the contradiction between the triangle inequality in latent metric spaces and the non-transitivity of complementarity principles. We develop a cross-geometric framework for the embedding of complementarity-driven networks and demonstrate that this representation allows for accurate embedding of real complementarity-driven networks.

Bio:

Dr. Kitsak is an assistant professor in the faculty of Electrical Engineering, Mathematics and Computer Science at the Delft University of Technology. Dr. Kitsak earned Ph.D. in theoretical physics from Boston University. Dr. Kitsak has held postdoctoral positions at the Center for Applied Internet Data Analysis (CAIDA), UC San Diego; and the Center for Complex Network Research (CCNR), Northeastern University. His research focuses on the development of theoretical and computational approaches to networked systems, with diverse applications ranging from systems biology to civil infrastructure. Results of his research have been published in top cross-disciplinary journals, such as Nature, Nature Physics, Science, and Science Advances, and have received broad media coverage.

PhD Defense Obaida Hanteer
2020-06-11 13:00 - 14:00 (Europe/Copenhagen)
Thesis: “A Practical and Critical Look at the Problem of Community Discovery in Multi-layer Networks”
Examination Committee:
Associate Professor Barbara Plank, IT University of Copenhagen, Denmark (Chair)
Professor Vito Latora, University of London, England
Dr. Luca Aiello, Nokia Bell Labs, England
Supervisor:
Associate Professor Luca Rossi, IT University of Copenhagen, Denmark
Co-supervisor:
Professor Irina Shklovski, University of Copenhagen, Denmark
Pre-registration:
For participation you must register here no later than 9 June 2020 at 3 PM. Upon registration, you will receive an invitation with a link to join the online defence no later than the workday before the defence.

Roberta @ SSC Catania
2020-03-29 19:00 - 21:00 (Europe/Copenhagen)
La matematica dei contagi

Roberta @ University of Barcelona
2020-02-11 15:00 - 17:00 (Europe/Copenhagen)
Keynote: Quantifying the biases of scientific success
International Day of Women and Girls in Science
Dones en la recerca scientifica

Lunch Seminar: Tiago Oliveira Cunha
2020-01-24 12:00 - 13:00 (Europe/Copenhagen) | 4E Wing
The first and newest postdoc of NERDS, Tiago Oliveira Cunha, will introduce and discuss his work in a lunch seminar on Friday, Jan 24th, 12:15-13:00 in the 4E wing.
Are All Successful Communities Alike? Characterizing and Predicting the Success of Online Communities
The proliferation of online communities has created exciting opportunities to study the mechanisms that explain group success. While a growing body of research investigates community success through a single measure — typically, the number of members — we argue that there are multiple ways of measuring success. Here, we present a systematic study to understand the relations between these success definitions and test how well they can be predicted based on community properties and behaviors from the earliest period of a community’s lifetime. Surprisingly, we find that the measures do not exhibit very high correlations, suggesting that they capture different types of success. Additionally, we find that different success measures are predicted by different attributes of online communities, suggesting that success can be achieved through different behaviors. Our work sheds light on the basic understanding of what success represents in online communities and what predicts it. This work was accepted as a full paper at The Web Conference 2019.

Roberta @ Leiden University
2019-12-12 - 2019-12-13 | CWTS, Leiden University, Leiden, Netherlands
Roberta will be at Leiden University, visiting and giving talks at CWTS

Invited Talk: Matteo Magnani, Multilayer networks meet databases: from property graphs to online information networks
2019-12-05 12:00 - 13:00 (Europe/Copenhagen) | ITU, 4A05
Abstract:
The analysis of complex online information requires the availability of rich data representation models and data analysis algorithms, for example multilayer networks and multilayer network clustering methods. At the same time, data analysis processes often require the ability to store raw data not yet prepared to perform a specific type of analysis, the possibility to enforce constraints guaranteeing some degree of data quality, and the capability to efficiently manipulate (or query) the raw data. This is for example important when performing interactive and visual data analysis, where several data dimensions, data subsets and aggregations have to be computed dynamically to explore different views over the data. In this work I present an extension of the multilayer network model providing database functionality on top of the idea of using the concept of layer to unify several types of graph-based models. This extension is based on the concepts of attributed vertex cube and attributed edge cube. I will conclude the presentation showing how to express a process to identify online conversations about specific topics in social media as a combination of cubes and cube operators.

Bio:
Matteo Magnani is an associate professor (“docent”) at Uppsala University, where he coordinates the Uppsala Information Laboratory (http://infolab.it.uu.se) and a new Master’s program in Data Science. Since 2011 he has developed and applied analysis methods for multilayer social networks in the context of national and European projects (FIRB and H2020 funding schemes). His results are described in his book “Multilayer Social Networks”, Cambridge University Press (2016), in several peer-reviewed publications, and implemented in the R multinet library (https://CRAN.R-project.org/package=multinet). He is also the recipient of a STINT initiation grant with TokyoTech on the topic of clustering temporal networks and of a NOS-HS grant for the establishment of a Nordic network on online disinformation. He has received the title of “Excellent teacher” (2016) and the UTN pedagogical prize (2013).

Invited talk Anna Sapienza, Understanding human behaviors and engagement in mobile app usage
2019-11-28 12:00 - 13:00 (Europe/Copenhagen) | ITU, 4A09
Abstract:
Recent years have seen an explosive growth in the use of mobile apps on smartphones and tablets. With over 2.7 billion smartphone users across the world checking their phones over 80 times a day, smartphone data offer a unique opportunity to understand main aspects of human behaviors, e.g., mobility, sleep patterns, and mobile app usage. Smartphones can be indeed a hugely productive tool. However, they interfere more and more with work, school, and relationships, sometimes leading engagement to become real addiction. It is indeed crucial to study how individuals interact with their phone and whether they are engaged and retained in the use of specific mobile apps. This talk will present the preliminary findings on user engagement in mobile apps, based on the study of an unprecedented dataset, including mobile app traces of thousands of users in time. I will show how users interact with smartphones over time with the aim of identifying the characteristics of users that are majorly engaged in mobile apps, the specific apps that are driving this engagement, and how usage patterns vary over time.

Bio:
Anna Sapienza is a Postdoctoral Researcher at the Department of Applied Mathematics and Computer Science at DTU. She holds a PhD in Applied Mathematics and her research is focused on modelling human behavior in online social environments, e.g., online social networks, applications, and games, through the analysis of high-dimensional data. She collaborates with the Copenhagen Center of Social Data Science (SODAS), where she studies phone usage activity and user engagement. Her research interests stay at the intersection between computational social science, machine learning, and network analysis.

Talk Michael Szell at Funders Forum on Sustainable Cities
2019-10-16 08:00 - 2019-10-17 17:00 (Europe/Copenhagen) | Turin, Turin, Italy

Invited talk Laura Alessandretti
2019-10-10 12:00 - 13:00 (Europe/Copenhagen) | ITU, 3A08, Rued Langgaards Vej 7, København, 2300, Denmark

Invited talk Jonas S. Juul
2019-10-03 12:00 - 13:00 (Europe/Copenhagen)

Colloquium at SISSA - Scuola Internazionale Superiore di Studi Avanzati
2019-09-25 | SISSA, Trieste, Italy
Roberta will give a Colloquium at SISSA. Here the link to the event.

DataBeers Copenhagen
2019-09-23 18:30 - 21:00 (Europe/Copenhagen) | H15, Halmtorvet 15, København, 1700, Denmark
NERDS members Roberta and Michael co-organize the second DataBeers event.

Invited talk Carlos Gershenson
2019-09-12 00:00 - 13:30 (Europe/Copenhagen) | ITU, 2A08, Rued Langgaards Vej 7, Copenhagen, 2300, Denmark
Prof. Carlos Gershenson from IINAS::UNAM will visit ITU on Sep 12th.
You’re invited to attend his lunchtime talk “Heterogeneity extends criticality”.

NERDS @ Techfest: The Future of Social Media Data Research
2019-09-07 13:00 - 15:00 (Europe/Copenhagen) | Rysensteen, Flæsketorvet 60, 1711 København, Flæsketorvet 60, , København, 1711, Denmark
We’re participating at Techfest 2019 a 3-day festival in Copenhagen with 200+ events on humans and technology.
We will coordinate a session about The Future of Social Media Data Research: Let’s Do It Right When it Comes to Data, Privacy and Public-Interest
Session presentation:
Social media has become a central data source for the study of individual as well as societal issues. The unprecedented scale and granularity of this type of data allow researchers to observe social dynamics as they unfold and hold high potential. Nevertheless, recent scandals and data-breaches such as in the case of Cambridge Analytica, and the social media platforms’ reaction, have shown the potential contradictions underlying this kind of research. Who holds the right to do public-interest research on this data? How to make it freely available for researchers? Who should be hold accountable?
This session will discuss these questions that will play a central role in shaping the future of research in many fields.

Roberta @ Metascience Conference 2019
2019-09-04 - 2019-09-08 | Stanford University, Palo Alto, CA, United States
Roberta will give an invited talk at the Metascience Conference 2019, hosted at Stanford University, in Palo Alto.

This is the topic of the conference:
During this decade, we have witnessed the emergence of a new discipline called metascience, metaresearch, or the science of science. Most exciting is the fact that this is emerging as a truly interdisciplinary enterprise with contributors from every domain of research. This symposium serves as a formative meeting for metascience as a discipline. The meeting will bring together leading scholars that are investigating questions related to themes such as:

How do scientists generate ideas?
How are our statistics, methods, and measurement practices affecting our capacity to identify robust findings?
Does the distinction between exploratory and confirmatory research matter?
What is replication and its impact and its value?
How do scientists interpret and treat evidence?
What are the cultures and norms of science?

Cambridge Network Day, University of Cambridge
2019-08-29 | Cambridge University, Cambridge, United Kingdom
Roberta gave an invited talk at Cambridge Network Day, the yearly conference of the Cambridge Networks Network, at the University of Cambridge.

Cambridge Networks Day 2019 is the sixth of our annual meetings on the topic of complex networks. It is an occasion for the research community to exchange ideas and expertise, intended to spark interdisciplinary collaborations. The day will include a diverse set of talks by invited speakers highlighting interest- ing new directions in the field of complex networks, as well as a poster session. We hope the day’s events will strengthen the interdisciplinary links between researchers and promote communication within the community.

ASONAM 2019 (4 Talks)
2019-08-27 - 2019-08-30
Presenting:
– Benchmarking API Systems for Social Media Data Collection
– Discovering Communities of Community Discovery
– The Impact of Projection and Backboning on Network Analysis
– Investigating Community Discovery Similarity Measures’ Behaviors

NERDS at Lipari Complex Networks workshop
2019-07-13 - 2019-07-19
NERDS Michele Coscia, Roberta Sinatra, and Michael Szell were invited to present their research at the workshop “Complex networks: from socio-economic systems to biology and brain” from the 13th to the 19th of July in Lipari.

Talk Michael Szell at Data Beers Copenhagen
2019-05-23 18:30 - 21:00 UTC | Byens Lys, Fabriksområdet 99, Copenhagen, 1440
The first edition of Data Beers Copenhagen will feature five talks, one of them given by NERDS member Michael Szell on “Understanding wasted mobility space with crowdsourced urban data”.
