The Infona portal uses cookies, i.e. strings of text saved by a browser on the user's device. The portal can access those files and use them to remember the user's data, such as their chosen settings (screen view, interface language, etc.), or their login data. By using the Infona portal the user accepts automatic saving and using this information for portal operation purposes. More information on the subject can be found in the Privacy Policy and Terms of Service. By closing this window the user confirms that they have read the information on cookie usage, and they accept the privacy policy and the way cookies are used by the portal. You can change the cookie settings in your browser.
The interrelationship of radiation and scattering characteristics was examined for the case of incident plane H-polarized wave onto an antenna in the form of a plane-parallel waveguide.
This paper presents and compares signal processing architectures for calculating point-by-point discrete signal spectra. Besides the well known Discrete Fourier Transform (DFT) and its well known fast implementation, the FFT, the Sliding Discrete Fourier Transform (S-DFT) and the less known Recursive Discrete Fourier Transform (R-DFT) are discussed. These algorithms are compared by calculation complexity...
This paper presents alternative methods of measuring the electric properties of antennas. In this case, the UWB impulse radar system is used. Also, the paper describes a relatively low cost measuring system, its calibration, verification and calculation methods of the required parameters - return loss and radiation pattern. All experimental results obtained by UWB radar are compared with the results...
In this paper, we present a novel compact hardware platform based on a microcontroller unit dedicated to evaluation and development of power analysis side-channel attacks and countermeasures against them. The platform is demonstrated by performing a correlation power analysis attack on a multi-precision multiplication which is part of various cryptographic protocols such as an elliptic curve digital...
The segment of post-quantum cryptography rises its importance with increasing improvements in the quantum computing. Cryptographic post-quantum algorithms have been proposed since 1970s. However, side-channel attack vulnerabilities of these algorithms are still in focus of the recent research. In this paper, we present a differential power analysis attack on the McEliece public-key cryptosystem. We...
Dielectric absorption of capacitors is a source of possible errors in the analog preprocessing blocks and integrating analog to digital converters. Parasitic relaxation components in the capacitor's model could be estimated by the decomposition of the charging multiexponential current. Paper deals with the possible preprocessing methods, selection of the optimal sampling conditions with the aim to...
The current study is dedicated to the investigation of stability issues occurring in switching power converters with non-ideal feedback circuitry. The interaction of nonlinear effects caused by the introduction of delay in the control circuitry of the compensated boost converters is studied by means of complete bifurcation diagrams, exploiting discrete-time modeling approach. The effectiveness of...
A dataset for hybrid indoor positioning systems is presented in this paper. The existing indoor positioning datasets are focused on a single technology such as WiFi RSSI or Magnetometer. But the presented dataset has data from W-LAN and Bluetooth interfaces, and Magnetometer. The measurements were performed in a three-story building and covers about 50% of the entire building. Moreover, both symbolic...
In this paper we deal with RLC or RLCG circuits, where some of the coefficients are influenced by a colored noise. Our approach to the mathematical description of this situation is via stochastic differential equations. We present numerical solutions of the corresponding equations. We compare the deterministic solution with the stochastic ones. We also compute and illustrate the corresponding confidence...
This paper is about using of the infinite impulse response (IIR) filters for the checking of the automatically scaled ionograms. This method is based on the detection of the extreme deviation in the data sequence of the ionospheric parameters (Total Electron Concentration, critical frequency of F2 layer and virtual height of F2 layer). Used types of the IIR filters are low-pass filters (Butterworth,...
In this work navigation algorithm based on open source software package RTKLIB with dead reckoning is presented. RTK mode allows improving the positioning accuracy using data from a base station. RTK functionality may be limited in conditions of poor visibility of satellites and there may be breaks navigation solutions. In these cases dead reckoning (DR) system allow to provide navigation for some...
The optical digital to analog converter (ODAC) concept is introduced to be used in an intelligent transportation system (ITS). The paper explores the performance of ODAC adapted into a traffic light head in order to enable transferring information from the infrastructure to the vehicle (I2V). The performance of such a scenario is shown by reconstructing error as a function of emitter placement, LED's...
The satellite signal drop can be caused either by atmospheric attenuation (rain, clouds, snow, …) either by unwanted satellite motion. This contribution demonstrates the software methods to extract the atmospheric attenuation from signal level record influenced by space satellite motion. Contribution is devoted to the construction of so called template (signal course in the case there is no atmospheric...
The article deals with description of spatial motion of the experimental radio-communications satellite Alphasat. The used Cartesian coordinates of the Alphasat satellite (given one week in advance in the OEM files of 5 minute resolution) are described. The coordinates conversion to the elevation and azimuth from the perspective of the receiver in Prague is added and described. This satellite motion...
In the paper, we introduce a novel neural estimator of seats occupied by passengers in a vehicle. The estimator is built from the radial basis function (RBF) neural network. Occupied seats in a vehicle are estimated from transmissions between antennas operating at 60 GHz.
A generalized methodology to optimize the design of single stage amplifier is described. It is observed that a wide variety of constraints applied to the objective function graphically forms a polytope type feasible region. Simplex method and interior point based method are then used to find an optimal value by traversing through each of the corner point and interior, respectively, of the polytope...
A novel chaotic oscillator with time delayed feedback is described in this paper. The oscillator is based on simple nonlinear circuit, gain stage and delay line. Chaotic systems are characterized by an extreme sensitivity to initial conditions. In this paper, instead of initial condition, the initial input wave (or voltage) is used. For chaotic system control also the gain of the amplifier is changed...
Recently, there is a high interest for appropriate systems and methods to localize the position of people and their devices in indoor environments (e.g. home, office, hospital). From technical and economical points of view, Bluetooth Low Energy (BLE) is one of the promising technologies in this field. This paper deals with the study of performances of this technology for these purposes. For the indoor...
The physical optics (PO) calculations have been utilized for numerical simulations of electromagnetic field above irregular ground. The PO approximation and numerical simulations using parabolic equation method are used for new comparison with findings of longstanding testing of microwave field and tropospheric refractivity profiles. It is demonstrated that the PO could offer reliable numerical simulations...
Set the date range to filter the displayed results. You can set a starting date, ending date or both. You can enter the dates manually or choose them from the calendar.