Category Archives: Publication

Two NERDS papers out: Measuring Violence via Twitter and Missing Links in Bike Networks

We start the spring with two new papers:

    1. Measuring Violence: A Computational Analysis of Violence and Propagation of Image Tweets From Political Protest, by L. Rossi, C. Neumayer, J. Henrichsen, and L.K. Beck, published in Social Science Computer Review

      We investigated the impact of violence on the propagation of images in social media in the context of political protest. Using a computational approach, we measure the relative violence of a large set of images shared on Twitter during the protests against the G20 summit in Frankfurt am Main in 2017. This allows us to investigate if more violent content is shared more times and faster than less violent content on Twitter, and if different online communities can be characterized by the level of violence of the visual content they share. The level of violence in an image tweet does not correlate with the number of retweets and mentions it receives that the time to retweet is marginally lower for image tweets containing a high level of violence and that the level of violence in image tweets differs between communities.
    2. Automated Detection of Missing Links in Bicycle Networks, by A. Vybornova, T. Cunha, A. Gühnemann, and M. Szell, published in Geographical Analysis

      Here, we develop the IPDC procedure (Identify, Prioritize, Decluster, Classify) for finding the most important missing links in urban bicycle networks, using data from OpenStreetMap. In this procedure we first identify all possible gaps following a multiplex network approach, prioritize them according to a flow-based metric, decluster emerging gap clusters, and manually classify the types of gaps. We apply the IPDC procedure to Copenhagen and report the 105 top priority gaps. For evaluation, we compare these gaps with the city’s most recent Cycle Path Prioritization Plan and find considerable overlaps. Our results show how network analysis with minimal data requirements can serve as a cost-efficient support tool for bicycle network planning.
      We also developed an interactive visualization of our results at: fixbike.net

First NERDS papers of 2022 published: Epidemic Dreams and Conflicts versus Polarization

We start 2022 with two new papers!

    1. Epidemic dreams: dreaming about health during the COVID-19 pandemic, by S. Šćepanović, L.M. Aiello, D. Barrett and D. Quercia, published in Royal Society Open Science

      Luca and collaborators ask: Why were our dreams during the pandemic weird? Their computer analysis unearthed buried psychological reactions to the COVID-19 pandemic: expressions in waking life reflected a linear and logical thought process and, as such, described realistic symptoms or related disorders (e.g. nasal pain, SARS, H1N1); those in dreaming life reflected a thought process closer to the visual and emotional spheres and, as such, described either conditions unrelated to the virus (e.g. maggots, deformities, snake bites), or conditions of surreal nature (e.g. teeth falling out, body crumbling into sand).
    2. How minimizing conflicts could lead to polarization on social media: An agent-based model investigation, by M. Coscia and L. Rossi, published in PLOS ONE
       

       The paper explores an agent based model on how policing content and backlash on social media (i.e. conflict) can lead to an increase in polarization for both users and news sources. We find that the tendency of users and sources to avoid policing, backlash and conflict in general can increase polarization online. Specifically polarization comes from the ease of sharing political posts, intolerance for opposing points of view causing backlash and policing, and volatility in changing one’s opinion when faced with new information. On the other hand, it seems that the integrity of a news source in trying to resist the backlash and policing has little effect.
      Learn more on Michele’s blogpost.

Two new NERDS papers: NFT market and Pearson correlations on networks

Two new papers from the NERDS crew!

    1. Mapping the NFT revolution: market trends, trade networks, and visual features, by M. Nadini, L. Alessandretti, F. Di Giacinto, M. Martino, L.M. Aiello, A. Baronchelli, published in Scientific Reports

      Luca and collaborators performed the first large-scale analysis of the market of Non Fungible Tokens (NFTs) since its birth. The looked at 6.1 million trades of 4.7 million NFTs to learn about market, traders, visual features and price prediction. The dataset they collected is available. Learn more on this blogpost from the Alan Turing Institute.
      Also, watch the accompanying video: https://www.youtube.com/watch?v=KyIITtPKJbY
    2. Pearson correlations on complex networks, by M. Coscia, published in Journal of Complex Networks
       

       
      Estimating the correlation between two processes happening on the same network is therefore an important problem with a number of applications. However, at present there is no way to do so: current methods to estimate the correlation between two processes happening on the same network either correlate a network with itself, a single process with the network structure, or calculate a network distance between two processes. To fill this gap, Michele created a new method to extend the Pearson correlation coefficient to work on complex networks, and showed its usefulness in tasks related to social network analysis and economics. Learn more on this blogpost.

Two NERDS summer papers: Streetonomics and COVID Twitter psychology

Prolific NERDS researcher Luca Maria Aiello published 2 more papers over the summer. They already received wide media coverage:

  1. Streetonomics: Quantifying culture using street names, by M. Bancilhon, M. Constantinides , E.P. Bogucka, L.M. Aiello, D. Quercia, published in PLOS ONE

    This paper studies the names of 4,932 honorific streets in the cities of Paris, Vienna, London and New York, finding that street names greatly reflect the extent to which a society is gender biased, which professions are considered elite ones, and the extent to which a city is influenced by the rest of the world, quantifying a society’s value system.

    The paper was covered in media here:
    https://www.bbc.com/future/article/20210712-streetonomics-what-our-addresses-say-about-us
    https://www.fastcompany.com/90652762/how-streets-in-new-york-london-paris-and-vienna-got-their-names-according-to-streetonomics
    https://www.thetimes.co.uk/article/street-names-show-why-great-cities-are-worlds-apart-x06lbdwgj
    https://elpais.com/ciencia/2021-06-30/el-machismo-esta-en-las-calles.html
    https://www.lefigaro.fr/sciences/l-ame-d-une-ville-peut-elle-se-lire-dans-les-noms-de-ses-rues-20210701

  2. How epidemic psychology works on Twitter: evolution of responses to the COVID-19 pandemic in the U.S., by L.M. Aiello, D. Quercia, K. Zhou, M. Constantinides, S. Šćepanović, S. Joglekar, published in Humanities and Social Sciences Communications

    The paper studies the use of language of 122M tweets related to the COVID-19 pandemic posted in the U.S. during the whole year of 2020. On Twitter, we identified three distinct phases. Each of them is characterized by different regimes of the three psycho-social epidemics.
    See also: https://www.fastcompany.com/90659372/pandemic-emotions-research-twitter

NERDS at ICWSM-2021

NERDS are currently active at this year’s International AAAI Conference on Web and Social Media (ICWSM): https://www.icwsm.org/2021/index.htmlThe International AAAI Conference on Web and Social Media (ICWSM) is a forum for researchers from multiple disciplines to come together to share knowledge, discuss ideas, exchange information, and learn about cutting-edge research in diverse fields with the common theme of online social media. This overall theme includes research in new perspectives in social theories, as well as computational algorithms for analyzing social media. ICWSM is a singularly fitting venue for research that blends social science and computational approaches to answer important and challenging questions about human social behavior through social media while advancing computational tools for vast and unstructured data.

As usual, Luca Maria Aiello fulfils his role as Senior PC member at ICWSM. Further, we published two new papers at the event:

  1. The Healthy States of America: Creating a Health Taxonomy with Social Media, by S. Šćepanović, L.M. Aiello, K. Zhou, S. Joglekar, and D. Quercia

    Since the uptake of social media, researchers have mined online discussions to track the outbreak and evolution of specific diseases or chronic conditions such as influenza or depression. Here we developed a Deep Learning tool for Natural Language Processing that extracts mentions of virtually any medical condition or disease from unstructured social media text. We applied it 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 the first comprehensive taxonomy of medical conditions automatically derived from online discussions, which strikingly resembles the official International Statistical Classification of Diseases and Related Health Problems (ICD-11).
  2. Multilayer Graph Association Rules for Link Prediction, by M. Coscia and M. Szell

    Here we investigate the multilayer link prediction problem with graph association rules: Will two nodes connect, and of which type?

Four new NERDS papers in May 2021

This month we have published four new papers, in Nature, Sustainability, IEEE Computer Graphics and Applications, and ACM Computing Surveys:

  1. The universal visitation law of human mobility, by M. Schläpfer, L. Dong, K. O’Keeffe, P. Santi, M. Szell, H. Salat, S. Anklesaria, M. Vazifeh, C. Ratti, G.B. West, published in Nature
    More info at the accompanying interactive website: https://senseable.mit.edu/wanderlust/

    This paper reveals a simple and robust scaling law that captures the temporal and spatial spectrum of population movement on the basis of large-scale mobility data from diverse cities around the globe.

  2. Implementing Gehl’s Theory to Study Urban Space. The Case of Monotowns, by D. Cerrone, J. López Baeza, P. Lehtovuori, D. Quercia, R. Schifanella, and L.M. Aiello, published in Sustainability

    The paper presents a method to operationalize Jan Gehl’s questions for public space into metrics to map Russian monotowns’ urban life in 2017. With the use of social media data, it becomes possible to scale Gehl’s approach from the survey of small urban areas to the analysis of entire cities while maintaining the human scale’s resolution.
  3. The Dreamcatcher: Interactive Storytelling of Dreams, by E.P. Bogucka, B.A. Aseniero, L.M. Aiello, D. Quercia, published in IEEE Computer Graphics and Applications

    Here we designed “The Dreamcatcher,” an interactive visual tool that explores the link between dreams and waking life through a collection of dream reports. We conducted a user study with 154 participants and found a 25% increase in the number of people believing that dream analysis can improve our daily lives after interacting with our tool. The visualization informed people about the potential of the continuity hypothesis to a surprising extent, to the point that it increased their concerns about sharing their own dream reports, thus opening new questions on how to design privacy-aware tools for dream collection.
  4. Community Detection in Multiplex Networks, by M. Magnani, O. Hanteer, R. Interdonato, L. Rossi, A. Tagarelli, published in ACM Computing Surveys

    Here we provide a taxonomy of community detection algorithms in multiplex networks. We characterize the different algorithms based on various properties and we discuss the type of communities detected by each method. We then provide an extensive experimental evaluation of the reviewed methods to answer three main questions: to what extent the evaluated methods are able to detect ground-truth communities, to what extent different methods produce similar community structures, and to what extent the evaluated methods are scalable. Besides offering a much needed overview of the methods and assumptions of CD in multiplex networks the paper attempts to provide few guiding principles for the choice of a community detection approach to multiplex data. 

New Paper on Sampling Social Media + Call for Abstract @ Networks21 Satellite

NERDS member Michele Coscia is having a busy March!

He published a new paper in the TKDD journal titled “Noise Corrected Sampling of Online Social Networks“. The paper focuses on a new way to perform topological network sampling, i.e. to explore a network by following its edges such that the explored (sub)network is as similar as possible to the whole structure. In this paper, the method uses a Bayesian framework to estimate the amount of novel information a new connection brings about into the currently explored sample.

He is also organizing a satellite for the Networks21 conference. The satellite is titled “Complex Networks in Economics and Innovation”. The organizers are looking for contributed abstracts on network applications on research about economic development and innovation. Read more on the official website, or submit your abstract to the submission site.

NERDS paper out: How unique is your app fingerprint?

We have a new exciting paper out: Temporal and cultural limits of privacy in smartphone app usage by Vedran Sekara et al. published in Nature Scientific Reports, asking:

How unique is your app fingerprint?The paper looks into which apps people use and creates app-fingerprints for 3.5 million individuals. Similar to forensic science where you need 12 points to distinguish between fingerprints we ask how many apps do we need to distinguish between two users? We find people’s smartphone app behavior is very unique and 3 apps are enough to identify more than 90% of all individuals. But app-fingerprints change over time and are different between countries. We find that people have more unique app-fingerprints during summer because we use more unique apps, and Americans have the most unique fingerprints (need the fewest apps to identify them) while Finns are the least unique (need more apps to identify their fingerprint). Why is this important? Because the work highlights problems with current policies intended to protect user privacy and emphasizes that policies cannot directly be ported between countries.

The Atlas for the Aspiring Network Scientist

In the past two years,  NERDS member Michele Coscia has been working on a textbook for the Network Analysis class he teaches at ITU. This “Atlas for the Aspiring Network Scientist”, has now reached version 1.0, and 760 pages, and is available for anyone to read for free: https://arxiv.org/abs/2101.00863

Website: https://www.networkatlas.eu/

The Atlas aims at being broad, not deep, to be a pointer to the things you need to know about Network Science rather than a deep explanation of those things.

Consider this a v1.0 of a continuous effort. There are many things to improve: language, concepts, references, figures. Please contact Michele with any comments.

Michele also plans to have interactive figures on the website in the future. Version 1.0 was all financed using his research money and time. For the future, Michele will need some support to do this in his free time. If you feel like encouraging this effort, you can consider becoming a member on Patreon.

Find a more detailed explanation of The Atlas for the Aspiring Network Scientist on Michele’s page: https://www.michelecoscia.com/?p=1913

Two NERDS December papers

We have published two new papers in December:

  1. The Node Vector Distance Problem in Complex Networks, by M. Coscia, A. Gomez-Lievano, F. Neffke, published in ACM Computing Surveys

    The paper develops a new measure to quantify the distances between sets of nodes, with important applications on network dynamics such as spread of diseases.
    Read Michele’s blog post about it: https://www.michelecoscia.com/?p=1898
  2. Data-driven strategies for optimal bicycle network growth, by L.G. Natera Orozco, F. Battiston, G. Iniguez, M. Szell, published in Royal Society Open Science

    Here we investigate the network structure of bicycle networks in cities around the world, and find that they consist of hundreds of disconnected patches, even in cycling-friendly cities like Copenhagen. To connect these patches, we develop and apply data-driven, algorithmic network growth strategies, showing that small but focused investments allow to significantly increase the connectedness and directness of urban bicycle networks.