2019, Vol. 21

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Recent Submissions

Now showing 1 - 5 of 27
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    Testovanie technológie XBee z hľadiska dosahu a stratovosti paketov
    (International Society for Science and Engineering, o.s., 2019-02-28) Zagajec, Lukáš; Orgoň, Miloš
    This article deals with the evaluation of XBee technology for packet reach and loss ina wireless communication network. The paper presents the results of the testing of several types ofsensors with the focus on the impact of their communication and packet loss in direct visibility andinstallation. The article also configures XBee chips with sensors that use the ZigBee PRO Series 1standard.
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    Rekonstrukce reálné a imaginární složky admitance válcového modelu pomocí elektrické impedanční tomografie
    (International Society for Science and Engineering, o.s., 2019-04-30) Dušek, Jan; Mikulka, Jan; Pařílková, Jana; Münsterová, Zuzana
    This paper is focused on experimental measurement and reconstruction of admittance via electrical impedance tomography. The beginning section contains brief introduction. The second part of paper describes complete electrode model. Principle of forward and inverse solution including the objective function minimized by the iterative Gauss-Newton method is explained together with influence of regularization. In addition to the algorithm, the tomograph environment is specified. The concept of measurement and simulation for reconstruction process is described. In the experimental part of the paper, the measured voltages and phase shift of signals are presented for homogeneous and inhomogeneous distribution of admittance (inside of tomograph). The measured voltages and phase shift of signals are used to reconstruct the real and imaginary distribution of admittance. The individual components of admittance are evaluated and employed to locate the real position of inhomogeneity. The results show that it is better to utilize the real part of the admittance to locate the inhomogeneous objects correctly.
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    Determinizace a logické řízení
    (International Society for Science and Engineering, o.s., 2019-04-30) Bokr, Josef
    Článek pojednává o determinizaci konečných automatů nedeterministických a s e-přechody; nové uvádí determinizaci automatu stochastického. Přínosně ukazuje, že výsledky determinizace automatů nejsou obecně přijatelné v logickém stavovém řízení.
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    Graficko-uživatelské rozhraní pro systém adaptivní síťové filtrace DoS útoků
    (International Society for Science and Engineering, o.s., 2019-04-30) Bachorec, Jan; Martinásek, Zdeněk; Gerlich, Tomáš
    In recent years, the intensity of Distributed Denial of Service attacks (DDoS) attacks hasbeen rapidly increasing and the attackers combine more often different techniques of DDoS to bypassthe protection. The main goal of our research project is to propose a DDoS solution that allows toincrease the filtering capacity linearly. In the article, we propose and implement a graphical userinterface for our DDoS defending system that operates in a data center of service provider. The maingoal of the defending system is to mitigate the impact of these attacks. Designed interface shows thebasic information about the attacks and interprets the impact on individual hardware resources.
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    Demonstrace metod snižujících pravděpodobnost chybného příjmu
    (International Society for Science and Engineering, o.s., 2019-04-30) Musil, Petr; Číž, Radim
    This article deals with prototype design of a laboratory device for demonstrating methods of probability reduction in bit error rate in terms of communication through channel with noise. Description of bit error probability and equations for determining its value, as well as description of each part of the offered design, including oscillograms capturing respective output signals are presented. The article also contains the measurement results, as well as the comparison to theoretical values determined by calculations for chosen span of noise level, which confirms the high accuracy of the presented design.