Based on transformation optics‎, ‎we propose an illusion device that can make‎ ‎objects look much smaller and different than they actually are‎. ‎In particular‎, ‎the device has a capability to hide a large object (like an elephant) into a‎ ‎small one (like a matchbox)‎. ‎Compared to previous proposals for illusion‎ ‎devices‎, ‎there is no requirement for negative refractive index or for spee...

Die Bereitstellung einer sicheren Umgebung zur Signaturerstellung stellt ein zentrales Problem beim praktischen Einsatz von digitalen Signaturen dar. Betrachtet man einen durchschnittlichen PC, oder gar einen öffentlich zugänglichen PC, so kann man nicht davon ausgehen, dass er unter alleiniger Kontrolle des Benutzers (des Signaturerstellers) ist. Die Sicherheit der Signaturumgebung lässt sich ...

In this paper, a deep learning (DL) framework for the optimization of resource allocation in multi-channel cellular systems with device-to-device (D2D) communication is proposed. Thereby, channel assignment and discrete transmit power levels D2D users, which are both integer variables, optimized maximization overall spectral efficiency whilst maintaining quality-of-service (QoS) users. Dependin...

Smartphones now-a-days are used mainly for surfing the web, checking social networks or playing games than making a phone call, which is only the fifth most frequent activity [5]. This means that users trust their smartphones to store and access sensitive data, ranging from contacts to financial details [3] (indeed 35% use their devices for online banking [2]). Moreover, a typical user now has ...