activity
20202023
most citedCorona-Warn-App: Tracing the Start of the Official COVID-19 Exposure Notification App for Germany

13 citations · 27 across the 7 of their papers we have counts for

collaborators

7 papers

cs.SI2023

Reviewing War: Unconventional User Reviews as a Side Channel to Circumvent Information Controls

José Miguel Moreno, Sergio Pastrana, Jens Helge Reelfs +6

During the first days of the 2022 Russian invasion of Ukraine, Russia's media regulator blocked access to many global social media platforms and news sites, including Twitter, Face…

cs.SI2022★ 1 cited

Characterizing the country-wide adoption and evolution of the Jodel messaging app in Saudi Arabia

Jens Helge Reelfs, Oliver Hohlfeld, Markus Strohmaier +1

Social media is subject to constant growth and evolution, yet little is known about their early phases of adoption. To shed light on this aspect, this paper empirically characteriz…

cs.SI2022★ 2 cited

Anonymous Hyperlocal Communities: What do they talk about?

Jens Helge Reelfs, Oliver Hohlfeld, Niklas Henckell

In this paper, we study what users talk about in a plethora of independent hyperlocal and anonymous online communities in a single country: Saudi Arabia (KSA). We base this perspec…

cs.SI2022★ 1 cited

Differences in Social Media Usage Exist Between Western and Middle-East Countries

Jens Helge Reelfs, Oliver Hohlfeld, Niklas Henckell

In this paper, we empirically analyze two examples of a Western (DE) versus Middle-East (SA) Online Social Messaging App. By focusing on the system interactions over time in compar…

cs.SI2021★ 8 cited

Understanding & Predicting User Lifetime with Machine Learning in an Anonymous Location-Based Social Network

Jens Helge Reelfs, Max Bergmann, Oliver Hohlfeld +1

In this work, we predict the user lifetime within the anonymous and location-based social network Jodel in the Kingdom of Saudi Arabia. Jodel's location-based nature yields to the…

cs.CY2020★ 13 cited

Corona-Warn-App: Tracing the Start of the Official COVID-19 Exposure Notification App for Germany

Jens Helge Reelfs, Oliver Hohlfeld, Ingmar Poese

On June 16, 2020, Germany launched an open-source smartphone contact tracing app ("Corona-Warn-App") to help tracing SARS-CoV-2 (coronavirus) infection chains. It uses a decentrali…

cs.CL2020★ 2 cited

Word-Emoji Embeddings from large scale Messaging Data reflect real-world Semantic Associations of Expressive Icons

Jens Helge Reelfs, Oliver Hohlfeld, Markus Strohmaier +1

We train word-emoji embeddings on large scale messaging data obtained from the Jodel online social network. Our data set contains more than 40 million sentences, of which 11 millio…