Informatyka, Automatyka, Pomiary w Gospodarce i Ochronie Środowiska

4-8

Authors: Tomasz Rymarczyk, Jan Sikora

Two ways of approximation of the BEM kernel singularity are presented in this paper. Based on these approximations extensive error analysis was carried on. As a criterion the preciseness and simplicity of approximation were selected. Simplicity because such approach would be applied for the tomography problems, so time of execution plays particularly significant role. One of the approximations which could be applied for the wide range of the arguments of the kernel were selected.

14-17

Authors: Volodymyr Barannik, Natalia Barannik, Oleksandr Slobodyanyuk

It is shown that the current direction of increasing the safety of information resources when transmitting information in info-communication systems is the use of methods of steganographic instruction in video imagery. The effectiveness of such methods is significantly increased when used in a complex of methods of concealment, which are based on the principles of inconsistent and cosmic communication. At the same time, existing methods of steganographic are used in the process of insertion of information mainly only laws, empty features of visual perception of video images. So, it is justified that the scientific and applied problem, which is to increase the density of embedded messages in the video container with a given level of their reliability, is relevant. The solution of this problem is based on the solution of the contradiction, which concerns the fact that increasing the density of embedded data leads to a decrease in the bit rate of the video container, steganalysis stability, reliability of special information, and video container. Therefore, the research aims to develop a methodology for the steganographic embedding of information, taking into account the regularities of the video container, which are generated by its structural and structural-statistical features. The solution to the posed problem of applying steganographic transformations is proposed to be realised by methods of indirectly embedding parts of the hidden message in certain conditions or functional relationships. The possibility of creating steganographic transformations regarding the indirect embedding and extraction of hidden information in a multiadic basis by modifying the underlying basis system within an admissible set is demonstrated. It is shown that the multiadic system, which is created in the spectral space of DCT transforms, has the potential to form a set of admissible modifications of basis systems.

22-27

Authors: Paweł Kowalski, Piotr Tojza

The article proposes an efficient line detection method using a 2D convolution filter. The proposed method was compared with the Hough transform, the most popular method of straight lines detection. The developed method is suitable for local detection of straight lines with a slope from -45˚ to 45˚. Also, it can be used for curve detection which shape is approximated with the short straight sections. The new method is characterized by a constant computational cost regardless of the number of set pixels. The convolution is performed using the logical conjunction and sum operations. Moreover, design of the developed filter and the method of filtration allows for parallelization. Due to constant computation cost, the new method is suitable for implementation in the hardware structure of real-time image processing systems.

32-37

Authors: Przemysław Falkowski-Gilski

Today, thanks to mobile devices, satellite communication is available to anyone and everywhere. Gaining information on one’s position using GNSS (Global Navigation Satellite Systems), particularly in unknown urban environments, had become an everyday activity. With the widespread of mobile devices, particularly smartphones, each person can obtain information considering his or her location anytime and everywhere. This paper is focused on a study, considering the quality of satellite communication in case of selected mobile terminals. It describes a measurement campaign carried out in varying urban environments, including a set of Android-powered smartphones coming from different manufacturers. Based on this, respective conclusions and remarks are given, which can aid consumers as well as device manufacturers and application developers.

42-46

Authors: Jacek Klimek

The article discusses the principle of operation and the structure of chirped and uniform gratings. It presents the method of producing gratings with monotonic apodisation characteristics, and compares the spectral features of produced gratings with the those obtained by mathematical modelling.

51-54

Authors: Bartłomiej Stefańczak

The article presents the design of a four-wire, three-level AC/DC converter. The converter was controlled with the use of a proportional-resonant controllers based voltage oriented control (VOC). The implemented topology of the AC/DC converter allows to control each of the phases separately. This translates into the possibility of independent control of active and reactive power in each of the phases. In addition, the DC bus of the AC/DC converter is connected in parallel with the energy storage via an isolated DC/DC converter and with a renewable energy sources. The tests were carried out with the use of the designed converter, DSP controller and Matlab/SIMULNIK platform, which was used for automatic code generation. The results obtained show that independent control of each of the phases is possible, however, the operation with large power unbalances on each of the phases leads to large current pulsation on the DC bus. This is a phenomenon that threatens the correct operation of the energy storage. As a result, the level of asymmetry between phases should be limited to the level acceptable by the energy storage.

62-66

Authors: Dawid Zarzeczny

Currently, various methods are used to assess the biocompatibility of materials. After an in-depth and detailed review of the literature, the method used in the research was selected. As part of the experiments, a method based on the analysis of the values ​​of electrical parameters of cell cultures measured in the presence of electrodes was used. The electrode is a structure made of a thin layer of metallization. It measures the change in resistance, impedance and capacity of a mixture of cells and the substance in which they are grown. The plate containing the electrode assembly is called the measurement matrix. Currently, commercially used test matrices are made of gold or platinum. However, their high price means that large-scale research is significantly limited. In order to increase the access to the widespread use of this method, it was decided that it was necessary to use cheaper materials, reducing the necessary costs of conducting experiments. Considering this, an attempt was made to use a different conductive material to build matrices compatible with the ECIS® Z-Theta measurement system. Their use would enable in vitro research on living cells. In the presented work, titanium was used as a material that may turn out to be an alternative to the materials currently used. Its application to the production of matrices will allow to study the influence of this metal on the behavior of cells.

75-77

Authors: Jarosław Tatarczak

This work presents measurement results of pollutants generated during 3D printing. The measure of pollutants is the concentration of particulate matter with a diameter of up to 2.5 μm (PM2,5). Materials acrylonitrile-butadiene-styrene (ABS), polyactide (PLA) for a 3D printer and low-cost particulate matter concentration sensors PMS3003, PMS7003 were used in the research. Research results show that low-cost sensors can be useful for monitoring pollution during 3D printing in offices, laboratories or private homes.