2021, Vol. 23


Recent Submissions

Now showing 1 - 5 of 12
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    Schopnosti dekódování videa jednotlivých modelù jednodeskového počítače Raspberry Pi
    (International Society for Science and Engineering, o.s., 2021-04-12) Benedikt, Jan
    The subject of the article is a comparison of selected generations of a single-board Raspberry Pi computer and their capabilities during the playback of multimedia video content. In the experimental measurement, four codecs were selected, which are currently the most used or the emerging standard. The specific codecs selected were AVC (Advanced VideoCoding) (H.264), HEVC (High Efficiency Video Coding) (H.265 ), AV1 (AOMedia Video 1) and VP9 (Video Predicator version 9). The test video files were generated in seven different resolutions (240p, 360p, 480p, 720p, 1080p, 1440p, and 2160p), with each resolution further subdivided into files of 24, 30, and 60 frames per second. Thanks to hardware support for decoding AVC and HEVC codecs, the 4B model showed the highest performance. The results showed that the slowest decoding of the video file occurred with the oldest model 2B. In contrast, the 4B model was able to decode video files the fastest.
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    Aplikace kompenzačních opatření pro systém vnitřních vodotěsných dveří do bezpečnostní politiky lodi dle IEC 62443
    (International Society for Science and Engineering, o.s., 2021-04-30) David, Ilja; Lukáš, Luděk
    The article focuses on the application of selected compensating countermeasures of cybersecurity into the security policy of the ship. First, the article presents the current state of cyber securityin the martime sector and explains recommended solutions according to international organizationsand relevant security standards. Further, the article analyzes why it is appropriate to address certainaspects of ICS cybersecurity by compensating countermeasures and is performed a security analysisof the system of internal integrated watertight doors according to IEC 62443-3-3 "Safety requirementsfor systems and required safety levels". Based on this analysis, suitable compensating countermeasureswere identified and applied to the security policy of the reference object of the cruise ship type.
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    Data-driven classification of events in the vicinity of an optical fibre
    (International Society for Science and Engineering, o.s., 2021-06-29) Galaz, Zoltan; Mekyska, Jiri; Prinosil, Jiri; Novotny, Vit
    This article focuses on the data-driven classification of vibration sources via a distributed optical fibre sensor system utilizing Gaussian Mixture Models and Mel-spectrograms. In total, six categories are considered: one person walking/running, group walking/running, hammering, and car riding. Two evaluation scenarios are used: individual models (per-session) and a joint model. Tenfold cross-validation is employed during the evaluation phase.
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    Návrh vysokootáčkového asynchronního motoru
    (International Society for Science and Engineering, o.s., 2021-07-13) Klíma, Petr; Ondrůšek, Čestmír; Mach, Martin
    This paper describes the design procedure of a 3 kW 180 000 rpm high-speed induction motor. It shows the connection between the electromagnetic a mechanical design of this type of machine. The focus of the paper are the rotor issues, which are mainly the considerable centrifugal forces, magnetic skin effect and bending shapes.
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    Vliv DLMS Security Suite na datový objem
    (International Society for Science and Engineering, o.s., 2021-09-01) Kohout, David; Mlýnek, Petr
    Smart Metering technologies represent new possibilities for electricity grid management. The safety requirements related to Czech legislation apply to communication within these technologies. As communication security is applied, the data volume grows, and this article examines how large this data increment is for each Security Suite level within DLMS (Device Language Message Specification).