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Creators/Authors contains: "Ibrahim, Ahmad"

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  1. ; (, The Astrophysical Journal)
    Abstract We point out the dominant importance of plasma injection effects of relativistic winds from pulsars and black holes. We demonstrate that outside the light cylinder, the magnetically dominated outflows sliding along the helical magnetic field move nearly radially with very large Lorentz factors,γ0≫ 1, imprinted into the flow during pair production within the gaps. Only at larger distances,r≥γ0(c/Ω), does MHD acceleration Γ ∝rtake over. As a result, Blandford–Znajek (BZ)-driven outflows produce spine-brightened images. The best-resolved case of the jet in M87 shows both edge-brightened features, as well as weaker spine-brightened features. Only the spine-brightened component can be BZ driven/originate from the black hole's magnetosphere. 
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    Full Text Available 
  2. ; ; ; ; ; ; ; (, International Conference on Embedded Software (EMSOFT))
    The Internet-of-Things (IoT) is a large and complex domain. These systems are often constructed using a very diverse set of hardware, software and protocols. This, combined with the ever increasing number of IoT solutions/services that are rushed to market means that most such systems are rife with security holes. Recent incidents (e.g., the Mirai botnet) further highlight such security issues. With emerging technologies such as blockchain and software-defined networks (SDNs), new security solutions are possible in the IoT domain. In this paper we will explore future trends in IoT security: (a) the use of blockchains in IoT security, (b) data provenance for sensor information, (c) reliable and secure transport mechanisms using SDNs (d) scalable authentication and remote attestation mechanisms for IoT devices and (e) threat modeling and risk/maturity assessment frameworks for the domain. 
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    Accepted Manuscript Full Text Available