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Number of results: 18
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Abstract

In the paper, a general topology of continuous-time Active-RC filter is presented. The model includes all possible Active-RC filter structures as particular cases and allows us to analyze them using a unified algebraic formalism. This makes it suitable for use in computeraided analysis and design of Active-RC filters. By its construction, the model takes into account the finite DC gain and the finite bandwidth as well as non-zero output resistance of operational amplifiers. Filters with ideal OPAMPs can be treated as particular cases. Sensitivity and noise analysis of Active-RC filters is also performed in the proposed general setting. The correctness of the model is verified by comparison with SPICE simulation.
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Abstract

In the paper, a feedforward linearization method for differential-pair operational transconductance amplifier (OTA) is discussed. The proposed technique is developed using simple differential pair transconductors and linear reference resistor. The concept leads not only to very efficient linearization ofa transfer characteristic oft he OTA but also others the possibility of effffective phase compensation. Due to this, the circuit can be used in applications requiring precise phase response (e.g. filters). SPICE simulations show that for the circuit working with a ±1.25V power supply, total harmonic distortion (THD) at 0.8Vpp is less then 0.1% in comparison to 10.2% without linearization. Moreover, the input voltage range ofline ar operation is increased. Power consumption oft he overall circuit is 0.94mW. The 3rd order elliptic filter example has been designed and simulated. It turns out that the proposed compensation scheme significantly improves the performance of the filter at higher frequencies.
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Abstract

For centuries, identity has been an important existential issue, because it organizes human relation with the world. Identity is not only one man's being in a biological sense, but the principle of social and cultural order. The identity is the self-awareness, the result of the social actor's involvement in a variety of network connections which are forming a human being together with the biological dimension. Thus, the identity, on the one hand, is a kind of Erikson's tradition, namely the sense of being human, on the other hand interactionist tradition, modification of identity through a process of interaction. Contemporary world, the world of confronting cultures, raises the need for analysis of identity within many cultures, which has been shaped by continuous contact with different values, norms, patterns of behaviour. Upper Silesia has been our empirical reference point for the discussion on social (regional) identity. Identity of Upper Silesia is the result of a long and complicated history and present day. This identity is created by Polish, German, Czech and Jewish a cultural elements.
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Abstract

Contemporary world brings along a continuing interpenetration of cultures strengthened by the migration revolution. The social space created by multiplicity of ethnic groups is very often a result of migration processes which totally formed such states as Canada or Australia. The sources of the European multiculturalism were, on the one hand, the officially accepted workforce, on the other hand – immigration being the effect of the colonial past of such states as France, Great Britain or Germany
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Abstract

The article presents the author’s considerations relating to the current and common problem of multiculturalism. Nowadays “multiculturalism” can be defined as co-existence – in the determined physical, social and political sphere as well as in a concrete historical period of time – of many ethnic groups representing different axiological and normative systems. The social created by multiplicity of ethnic groups is very often a result of migration processes which totally formed such states as Canada or Australia. The sources of the European multiculturalism were, on the one hand, the officially accepted workforce as Federal Republic of Germany, on the other one – immigration being the effect of the colonial past of such states as France, Holland or Britain. All these countries took up more or less advanced actions towards being able to deal with the deepening ethnic diversification. There appeared political project – multiculturalism.
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Abstract

One of the mathematical tools to measure the generation rate of new patterns along a sequence of symbols is the Lempel-Ziv complexity (LZ). Under additional assumptions, LZ is an estimator of entropy in the Shannon sense. Since entropy is considered as a measure of randomness, this means that LZ can be treated also as a randomness indicator. In this paper, we used LZ concept to the analysis of different flow regimes in cold flow combustor models. Experimental data for two combustor’s configurations motivated by efficient mixing need were considered. Extensive computer analysis was applied to develop a complexity approach to the analysis of velocity fluctuations recorded with hot-wire anemometry and PIV technique. A natural encoding method to address these velocity fluctuations was proposed. It turned out, that with this encoding the complexity values of the sequences are well correlated with the values obtained by means of RMS method (larger/smaller complexity larger/smaller RMS). However, our calculations pointed out the interesting result that most complex, this means most random, behavior does not overlap with the “most turbulent” point determined by the RMS method, but it is located in the point with maximal average velocity. It seems that complexity method can be particularly useful to analyze turbulent and unsteady flow regimes. Moreover, the complexity can also be used to establish other flow characteristics like its ergodicity or mixing.
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