Category Archives: Student

New paper on the effectiveness of epidemic mitigation strategies

New Nerds paper out! Congratulations to our PhD student Morten Rahbæk Boilesen on publishing his first article!

Are fast test results preferable to high test sensitivity in contact-tracing strategies? This question is addressed by Morten Rahbæk Boilesen, Kaare Græsbøll and Jonas L. Juul in their modelling study of the dynamics of contact tracing, testing and isolation strategies in epidemic outbreaks. Here is a description of their paper:

During disease outbreaks, public health officials might face a decision on whether to use rapid tests that give quick but sometimes inaccurate results, or slower and more precise tests. This choice matters because delays in diagnosis slow down contact tracing, allowing infected and their potential secondary infections to spread illness longer.

Here, we use mathematical modeling to examine the trade-off between test speed and test accuracy. We use the mathematical model to simulate epidemic outbreaks with different levels of contact tracing efficiency, test turnaround time and test sensitivity. In each case, we evaluate whether disease mitigation is best with slow-and-accurate tests or fast-and-inaccurate tests.

For diseases similar to COVID-19, we find that accurate tests with test turnaround time less than four days generally reduce transmission better than rapid, less reliable tests. However, when contact tracing is highly efficient, faster results become advantageous.We show that if test sensitivity is proportional to the viral loads of the infected, rapid tests become more favourable overall as opposed to modelling the test sensitivity as a constant value independent of the viral loads of the infected.

Finally, our analysis shows that when contact tracing isn’t feasible, neither rapid nor accurate testing outperforms simply having people self-isolate without testing infrastructure.

This work can help guide testing strategy decisions when an epidemic is raging, revealing that prioritizing speed can become a viable strategy to reduce transmission when testing infrastructure is under stress.

A figure showing effective reproduction number under mitigation strategies.

Anders Giovanni Møller defends his PhD: “AI in Modern Society: From computational methods to societal consequences”

Big congratulations to Anders for successfully defending his PhD thesis on how AI is changing Computational Social Science and the Web. The Committee was composed by Elisa Mekler, Robert West, and Johannes Bjerva. His very proud supervisor is Luca Aiello.

During his three years with NERDS, Anders has published 6 papers in the areas NLP and CSS, pioneering topics such as synthetic data generation with LLMs and AI persuasion. His graduation officially concludes the COCOONS project.

Anders has now started a job in the industry as AI Lead of Polaris, in Copenhagen.

In bocca al lupo, Anders!

Marcus Friis has joined NERDS

Marcus joins us as a new PhD Student. With a background in Data Science, and experience from the danish news media Politiken, he is a perfect fit! Marcus also plays the trumpet in his free time. He will work with Vedran Sekara on uncovering how climate change impacts human behaviors.

Marcus will work on the Climate Adapt project funded by Independent Research Fund Denmark (DFF) and we hope insights from the project will ultimately provide data-driven recommendations to policy makers on how to design effective responses to climate change.

We are thrilled to have you on board, Marcus!

Arianna Pera defends her PhD: The Language of Collective Action in the Social Web

Big congratulations to Arianna for successfully defending her PhD thesis on the role of language in fostering grassroots collective action. The Committee was composed by Luca Rossi, Fabiana Zollo, and Sune Lehmann. Her very proud supervisor is Luca Aiello.

Collage with three pictures 1) Arianna presenting her work, 2) Arianna posing with members of the Committee (Luca Rossi, Sune Lehmann) and with her advisor (Luca Aiello) 3) Arianna and many NERDS nighttime celegration

During her three years with NERDS, Arianna has published 7 paper in the areas of mobilization framing, computational narratives, and applied NLP. She has become a very active member of the international Computational Social Science community, which will benefit from her work for many years to come.

On March 1st she will start a research position at SODAS with Clara Vandeweerdt.

In bocca al lupo, Arianna!

Luigi defends his PhD: Polarisation in an Evolving Social Media Landscape

Big congratulations to Dr. Luigi Arminio. Yesterday he defended his thesis on Polarisation in an Evolving Social Media Landscape: Multimodal Insights from the Climate Debate.

Supervisor: Luca Rossi
Committee: Luca Aiello, Cornelius Puschmann, Cindy Shen

We are extremely happy and proud of Luigi’s research dealing with the crucial issue of online polarisation and producing both substantial contribution as well as methodological advancements.

Luigi’s work is built on 6 papers and investigated both textual and visual data. On the textual side he showed how opposite groups in a polarised debate are recognisable by specific socio-linguistic feature that we can detect computationally. On the visual side he contributed to the development of a research pipeline that leverages Visual Large Language Models to produce semantic clustering of visual content. This was then used to study the ongoing visual narratives surrounding the climate debate.

On March 1st Luigi will start a research position at Roskilde University in the context of the Algorithms, Data & Democracy project but we know that our collaboration isn’t over.

Manuel Knepper has joined NERDS

We welcome our latest NERDS member: Manuel Knepper.

Manuel, who is already guest at NERDS since a few months, joins now as a research assistant for one year, after having finished a master in data science here at ITU with Michele and Anastassia on predicting cyclist flows with machine learning methods.

Manuel will work with Michael and Anastassia on the recently won InnoExplorer grant as research software engineer to turn raw bicycle network algorithms into packaged Python software usable for urban planners, helping us close the gap between research and policy/application. Manuel’s background, his thesis, and also his industry experience with data and software engineering makes him a perfect fit for this role. Besides, Manuel will also be teaching assistant for the geospatial data science course in spring.

We are excited to have you with us, Manuel. Welcome!

Ditte Bjerregaard has joined NERDS

We welcome our latest NERDS member: Ditte Bjerregaard.

Ditte joins as a new PhD student, coming with a background in anthropology, and as the founder and director of the Center for Violence Prevention (Center for Voldsforebyggelse, https://centerforvoldsforebyggelse.com/).

Ditte will work with Michele Coscia, using data from police reports and court cases involving femicide, to understand the determinants and, hopefully, create early warning systems. We are excited to have you with us, Ditte. Welcome!

Morten Boilesen has joined NERDS

We welcome our latest NERDS member: Morten Boilesen.Headshot of Morten

Morten joins as a new PhD student, coming with degrees in mathematics, musicology, and engineering, and experience as a start-up data scientist.

Morten will work with Jonas L Juul on the InForM project (funded by the Novo Nordisk Foundation), using Danish register data to study how COVID-19 spread in Denmark. 3 exciting years ahead! We are excited to have you with us, Morten. Welcome!

Ane defends her PhD: Network analysis of Denmark’s bicycle infrastructure

Big congratulations to Dr. Ane Rahbek Vierø – she defended her thesis yesterday, on Network Analysis of Denmark’s Bicycle Infrastructure: Data & Infrastructure for All? 🥳 🎓 We are proud about Ane’s brilliant scientific accomplishments that have also started to have a big practical impact on bicycle network planning nationally and internationally.

Supervisor: Michael Szell
Committee: Michele Coscia, Trine Agervig Carstensen, Trivik Verma

Read her thesis here: https://en.itu.dk/Research/PhD-Programme/PhD-Defences/PhD-Defences-2025/May/Ane-Rahbek-Vier_

The thesis spans 5 papers that advance data and network analysis of bicycle infrastructure, from the 3 perspectives of 1) data foundations, 2) spatial patterns of bikeability, 3) linking research and planning. Unique achievements are the analysis of a whole country’s (Denmark’s) bicycle infrastructure and network, with the creation of open source tools. The thesis also concludes a project funded by the Danish Ministry of Transport / Road Directorate.

In her research Ane reveals that bicycle infrastructure data often suffer from inconsistencies and low quality, reflecting historical underinvestment in active mobility data. This data heterogeneity creates an information gap and necessitates extensive preprocessing, creating barriers to cycling research and planning. Additionally, she finds that bikeability and access to low-stress cycling infrastructure are highly spatially clustered, with substantial disparities between urban and rural areas. While urban areas generally benefit from better cycling conditions, large segments of the Danish population are deprived of the advantages of active mobility. The geographical differences in bicycle infrastructure access and data quality highlight the need for a spatial perspective in cycling research. Finally, she demonstrates that data-driven tools can aid bicycle planning by generating insights into complex planning questions that involve large geographical areas.

With her PhD completed, Ane has already started a research position at Roskilde University, where she remains at least for the short term. We are both sad to “lose” Ane with her friendly, collegial spirit and unreplaceable skill set, and happy for her success and positive impact in the world. That being said, we are not finished collaborating, and will always be happy to see Ane around.

Paper & Viz: Analysis of Denmark’s whole bicycle network

Today we published the paper which marks the Grand Finale of Ane’s PhD, which she will defend this thursday, May 22nd, in Auditorium 2 at ITU: https://en.itu.dk/Research/PhD-Programme/PhD-Defences/PhD-Defences-2025/May/Ane-Rahbek-Vier_

Her thesis is “Network Analysis of Denmark’s Bicycle Infrastructure: Data & Infrastructure for All?”, of which an important part is the paper:

Network Analysis of the Danish Bicycle Infrastructure: Bikeability Across Urban–Rural Divides, by A.R. Vierø and M. Szell, published in Geographical Analysis

To bridge the gap between urban and rural cycling research, we analyze the bicycle network of Denmark, covering around 43,000 km2 and nearly 6 million inhabitants. We divide the network into four levels of traffic stress and quantify the spatial patterns of bikeability based on network density, fragmentation, and reach. We find that the country has a high share of low-stress infrastructure, but with a very uneven distribution. The widespread fragmentation of low-stress infrastructure results in low mobility for cyclists who do not tolerate high traffic stress. Finally, we partition the network into bikeability clusters and conclude that both high and low bikeability are strongly spatially clustered. Our research confirms that in Denmark, bikeability tends to be high in urban areas. The latent potential for cycling in rural areas is mostly unmet, although some rural areas benefit from previous infrastructure investments. To mitigate the lack of low-stress cycling infrastructure outside urban centers, we suggest prioritizing investments in urban–rural cycling connections and encourage further research in improving rural cycling conditions.

With the paper comes an interactive visualization of the whole bicycle network of Denmark! Check it out at: bikenetwork.dk

This achievement also marks the conclusion of all our “deliverables” for the Vejdirektoratet grant by the Danish Ministry of Transport which financed Ane’s Phd.

If you are around ITU, don’t miss Ane’s defense on thursday!