Wyniki 1-7 spośród 7 dla zapytania: authorDesc:"Pawel ZUKOWSKI"

A method of syntactic text steganography based on modification of the document-container aprosh DOI:10.15199/48.2018.06.15

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The development of information technology has led to the fact that now they put the information on a par with the generally accepted material values. Access to it with the advent of global computer networks has become incredibly simple. Simplicity and speed of such access significantly increased both the threat of data security breach, as well as the threat of unauthorized access (without author's permission) to information. The main objects of copyright relating to information technologies, including publishing technologies, are: paper and electronic versions of various text or other documents, databases, computer programs. This means that Internet objects also refer to intellectual property. The logic of regulating the Internet itself and the relations connected with the use of its resources and capabilities should be in the plane of both national and international law. Thus, the problem of protecting information and protecting copyright for text documents is becoming increasingly important. A method of solving of this problem on the basis of text steganography is investigated and analyzed in some articles, for example [1]. The specifics of algorithmic and software implementation of the steganographic methods that are based to protect of digital documents against unauthorized use are analyzed in [2]. Contrary to cryptography which purpose is hiding data by encrypting them, the purpose of steganography is to hide the fact of the transfer of confidential messages. It is because of steganography system of protection is achieved the greatest degree of resistance to intentional attacks to destroy or to identify hidden information. The steganographic system (stegosystem or steganosystem) - a set of tools and techniques that are used to form a secret channel of information transfer [3-5]. The steganosystem forms the channel, that carries the filled container. This channel is considered to be exposed to the influence from the [...]

Analysis of thermal processes in oil distribution transformer DOI:10.12915/pe.2014.05.017

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Paper deals with the analysis of thermal processes in oil distribution transformers. By means of the mathematical analysis and experimental measurements it is possible to diagnose of power oil transformers in terms of mechanical strength of winding. Analysis of warming at varying loads is very importance, since allows determining the load capacity and overload of the transformer under various operating conditions and respecting the variable ambient temperature. Streszczenie. Artykuł dotyczy analizy procesów termicznych w rozdzielczych transformatorach olejowych. Za pomocą analizy matematycznej I pomiarów doświadczalnych można dokonać diagnozy olejowych transformatorów mocy pod względem wytrzymałości mechanicznej uzwojenia. Analiza nagrzewania się uzwojeń przy zmiennych obciążeniach jest bardzo ważna, gdyż pozwala na określenie nośności i przeciążenia transformatora w różnych warunkach eksploatacji w odniesieniu do zmiennej temperatury otoczenia. (Analiza procesów termicznych w rozdzielczych transformatorach olejowych). Keywords: transformer, thermal processes, thermovision, windings, temperature. Słowa kluczowe: transformator, procesy termiczne, termowizja, uzwojenia, temperatura. doi:10.12915/pe.2014.05.17 Introduction Electric energy lost in transformer in conversion of alternating current is converted into heat in winding, magnetic circuit and in other parts of the transformer. At the same time transformer heat´s up and the temperature of its individual parts can greatly exceed the ambient temperature. With increasing load and with emerging losses the temperature of the transformer rises, this all depends on cooling winding, magnetic circuit and other heated parts. As far as temperature, transformer is inhomogeneous element. Sheets of magnetic circuit are characterized by high thermal conductivity and relatively low thermal capacity. They are taking turns with layers of insulation (lacquer etc.), whose thermal[...]

Simulation of neutron irradiation influence on p-n-p bipolar transistor characteristics DOI:10.15199/48.2016.11.57

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We have developed numerical model and software to simulate the ionizing radiation influence on the bipolar transistor parameters. The software allows to calculate the input and output characteristics, the current transmission coefficient and other parameters under the irradiation for various temperatures, base and collector voltages. Streszczenie. Opracowaliśmy model numeryczny i oprogramowanie do symulacji wpływu promieniowania jonizującego na parametry tranzystorów bipolarnych. Oprogramowanie pozwala obliczyć parametry wejściowe i wyjściowe, aktualny współczynnik transmisji i inne parametry na podstawie napromieniowania dla różnych temperatur, napięć bazy i kolektora. (Symulacja wpływu promieniowania neutronowego na charakterystyki p-n-p tranzystorów bipolarnych). Keywords: bipolar transistors, neutron flow, transmission coefficient, output characteristics. Słowa kluczowe: tranzystor bipolarny, przepływ neutronów, współczynnik transmisji, charakterystyki wyjściowe. Introduction Nowadays, the bipolar transistors are extensively used in many sectors of micro- and nanoelectronics as the amplifiers, generators, keys, regulators etc. Their operation in the radiation environment, e.g. in the open space, on the nuclear power plants, during the nuclear blast etc. can be difficult through the radiation-induced changes in operating parameters. The forecasting of these changes is a one of the main problems of development and production of the radiadiation-resistant hardware. The computer simulation is the most optimal method to resolve this problem. The subject We consider the p-n-p bipolar transistor that is the part of integral structure shown in figure 1. Fig.1.[...]

Fabrication and characterization of transparent tin dioxide films with variable stoichiometric composition DOI:10.15199/48.2016.08.51

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Tin dioxide films with variable stoichiometric composition were fabricated by means of DC magnetron sputtering followed by a 2-stage annealing process. The structural and electrical properties of tin dioxide films were investigated by means of Raman spectroscopy and impedance spectroscopy, respectively. It was found that crystallinity and grain size of tin dioxide films increase with the increasing of annealing temperature. The most conductive samples were obtained at the annealing temperature 375°C on the 2-nd stage of the heat treatment procedure. Increasing of the impedance of films annealed at higher temperatures is explained by decrease of the concentration of oxygen vacancies. Streszczenie. Folie z dwutlenku cyny o zmiennym składzie stechiometrycznym zostały wytworzone za pomocą rozpylania magnetronowego przy użyciu prądu stałego oraz poddane dwuetapowemu wygrzewaniu. Właściwości strukturalne oraz elektryczne folii zostały zbadane przy użyciu spektroskopii ramanowskiej i spektroskopii impedancyjnej. Ustalono, że krystaliczność oraz rozmiary ziaren folii z dwutlenku cyny zwiększają się wraz ze wzrostem temperatury wygrzewania. Najbardziej przewodzące próbki zostały poddane wygrzewaniu w temperaturze 375°C w drugim etapie obróbki cieplnej. Wzrost impedancji folii wygrzanych w temperaturach wyższych jest związany ze zmniejszeniem koncentracji wakansów tlenu. (Wytwarzanie i charakterystyki przezroczystych folii z dwutlenku cyny o zmiennym składzie stechiometrycznym). Keywords: stoichiometric composition, magnetron sputtering, electrical properties, impedance spectroscopy. Słowa kluczowe: skład stechiometryczny, rozpylanie magnetronowe, właściwości elektryczne, spektroskopia impedancyjna. Introduction Coexistence of excellent optical transparency in the visible range of electromagnetic spectrum and high electrical conductivity of tin dioxide films provides possibility for applications as transparent conducting electrodes in optoelectroni[...]

Diagnostics of transformer with insulation oil-paper DOI:10.15199/48.2015.08.18

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Artykuł omawia metody opisujące stan izolacji transformatorów. Przez określenie jej stanu jest poznanie pomiarów napięcia powrotnego oraz pomiarów rezystancji izolacji uzwojeń. Metoda pomiaru napięcia powrotnego jest metodą szeroko opisującą stan, która nie jest objęta normami ale w wielu przypadkach umożliwia uzyskanie jasnych i dokładnych wyników. Wyniki przede wszystkim pokazują zawartość wilgoci, zawartość przewodzących zanieczyszczeń w oleju oraz wpływ stopnia starzenia na papier izolacyjny. (Diagnostyka transformatorów z izolacją papierowo-olejową). Abstract. The article deals with method describing the state of transformer insulation. By the determining its state is acquainted return voltage measurement and measurement the insulation resistance of windings. Return measurement voltage method is wide state specifying method which is not set in standards but in many cases is a method which is determining a clear and exact result. The results have mainly shows moisture content, content of conductive impurities in oil and degree of aging of paper insulation impact. Słowa kluczowe: napięcie powrotne, rezystancja izolacji, wskaźnik polaryzacji, transformator. Keywords: return voltage, insulation resistance, polarization index, transformer. Introduction Influence of operating conditions leads to aging of individual parts of transformer, and also to changes of the major electrical and mechanical properties. To the check of the condition greatly contributes electro-technical diagnosis, whose main task is to find a clear relation between the change in functional characteristics of the machine and some measurable values. The assessment of these measured values must be visible not only the rate of change, but also whether it is a permanent or reversible state. The aim of diagnostics of transformers is to verify that the machine complies with the determined conditions in accordance with standards [1]. Economically reliable and effective po[...]

Diagnostics and measurement of the gasoline engines injection system DOI:10.15199/48.2015.08.20

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W pracy przedstawiono wyniki badań elektronicznego system wtrysku paliwa, które mogą być stosowane w kwestiach diagnostycznych. Opisano konstrukcję i pracę typowego systemu wtrysku paliwa, a także przeanalizowano jego elektroniczną część. Zaproponowano również metodę wykrywania wadliwego wtryskiwacza, bazującą na analizie charakterystyk prądu różnicowego. Wykazano różnice w parametrach elektrycznych poszczególnych wtryskiwaczy paliwa, które mogą być poprawione np. dzięki odpowiednim algorytmom samokształcenia. (Diagnostyka i pomiar układu wtryskowego silników benzynowych) Abstract. The paper presents the electronic fuel injection system research results, which can be used in diagnostic issues. Have been described the construction and operation of a typical fuel injection system and analysed its electronic part. It has also been proposed method for the detection of the injector malfunction, based on the analysis of differential current characteristic. Have been shown differences in the electrical parameters of the individual fuel injectors, which can be corrected e.g. by suitable self-learning algorithms. Słowa kluczowe: elektroniczny wtryskiwacz paliwa, diagnostyka, pomiar, charakterystyka prądu różnicowego. Keywords: electronic fuel injector, diagnostics, measurement, current characteristic analysis. Introduction Electronic fuel injector is an important part of the engine gasoline fuel system. The fuel injector is a solenoid valve. Forces which act on the active injector core are caused by friction, spring tension and fuel pressure. Rising current curve is partially different from the curve of an ideal inductor current. The effect which causes a change of perme[...]

The delay line with a surface acoustic wave for an oscillator of electric signals in some sensors DOI:10.15199/48.2018.03.38

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As selective elements of oscillators of harmonic vibration besides the band-pass filters are also used delay lines (DL) and resonators as a perspective a coustic-electric components based on surface acoustic waves (SAW). From the stability point of view we can classify these oscillators among the ones with volume acoustic waves and LC oscillators. In the article, the DL with SAW for single - mode oscillators. The oscillator with delay line The basic principle of function of oscillator with delay line is represented on the next figure (Fig. 1). The delay line (4) with SAW plugged in the feedback of amplifier (2) is a basic element. Circuits (1, 3) serve to match impedance of the abovementioned to the impedance of the electronic circuitry. Fig.1. Bloc diagram of oscillator. Because the previous signal from the input to the output of DL is delayed, examined oscillators are ones with delayed feedback. The theory of these oscillators is well known in the literature [1]. Different situation is in the case of DL with SAW, where DL themselves have narrow transmission band and their parameters differ fundamentally in this range. Physical distinctiveness of functioning of listed components which are related with phenomena of excitation, extension and reflection of SAW cause that in addition to delay, the DL´s have specific frequency dependencies of input and output admittances. Their replacement with the lumped elements RLC circuit or broad - band DL with outer selective LC is mentioned only very general. The oscillator with mismatched delay line The used delay line with SAW as a selective element of oscillator can be symmetrical or non-symmetrical. Symmetrical DL is characterized by the same input and output IDT while non-symmetrical DL has the input IDT with small number of electrodes (broadband) and output IDT with big number of electrodes (narrowband). In the contribution we will only deal with the symmetrical DL. For simpl[...]

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