• Please use real names.

    Greetings to all who have registered to OPF and those guests taking a look around. Please use real names. Registrations with fictitious names will not be processed. REAL NAMES ONLY will be processed

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  • Welcome to the new site. Here's a thread about the update where you can post your feedback, ask questions or spot those nasty bugs!


  1. Jerome Marot

    Contact tracing app.

    Apple and google are jointly developing a contact tracing app that would tell people if they were near a infected people in the past 2 weeks. The underlying mathematics are interesting. How do the apps work? A naive approach would be to store the position of the whole population all the time...
  2. Jerome Marot

    In Perspective, Fun: Modern times

    I find this amusing:
  3. Jerome Marot


    I suppose you read the news that Google (actually, Alphabet, its parent company) is cutting off Huawei's access to Android. Things are not that simple, however. But first: why is this important? Let me give some figures. There are about 2 billions smartphones on this planet. Smartphones make...