Nonlinearities in optical fibers deteriorate system performances and become a major performancelimiting issue. This article aims to investigate the compensation of nonlinear distortions in optical communication systems based on different wavelength propagations over few-mode fiber (FMF). The study adopted Space Division Multiplexing (SDM) based on decision feedback equalizer (DFE). Various transmission wavelength of the FMF system is applied to mitigate the attenuation effect on the system. In this paper, different wavelengths (780, 850 and 1550 nm) are used in SDM. Extensive simulation is performed to assess the attenuation and Bit Error Rate (BER) in each case. The results show that the wavelength of 1550 nm produces higher power and less attenuation in the transmission. Furthermore, this wavelength produces the best distance with less BER compared to 780 nm and 850 nm wavelengths. Moreover, the validations show improvement in BER and eye diagram.
The paper presents the equalization problem of non-linear phase response of digital IIR type filters. An improved analytical method of designing a low-order equalizer is presented. The proposed approach is compared with the original method. The genetic algorithm is presented as an iterative method of optimization. The vector and matrix representation of the all-pass equalizer are shown and introduced to the algorithm. The results are compared with the analytical method. In this paper we have also proposed the use of an aging factor and setting the initial population of the genetic algorithm around the solution provided by the analytical methodology
This is the first insight into effect of development of nonpublic and paid schools on social stratification in Poland. Logistic and multinomial regression of the Polish general Social Survey data 1998 is conducted to test hypotheses concerning effect of the fathers’s EGP category on access to various types of schools in secondary and tertiary education. Results confirm the hypotheses that respondents from intelligentsia families are overrepresented in both secondary and tertiary paid schools and have greater odds of entry in to public tertiary education in comparison to lower non-manual categories, owners, working class and peasants. Children of intelligentsia also have more opportunities to attend “better” stationary (than non-stationary) schools in comparison to other categories. This analysis provides support for the thesis about growing role of qualitative differentiation in education.
The article discusses views and the ideological evolution carried out by Pitirim Alexandrovich Sorokin, a Russian-American sociologist, philosopher and political activist. Influenced by his observations of the events of 1917, Sorokin radically reformulated his opinions about Marx and Marxism which resulted in his espousing of a traditionalist and anti-revolutionary position. He still shared with Marx his negative diagnosis of the modern world, but proposed a different solution as a remedy. His solution was a purification of the idea of equality by liberating it from reductive materialism. Nevertheless Sorokin’s concept of spiritual equality was as utopian as Marx’s. He presented his ideas in a littleknown novel titled: Предтеча (or Прачечная человеческих душ – ‘предтеча’ means ‘ancestor’ and is commonly referred to John the Baptist). This work is a signal for Sorokin’s denial of Marx’s ideas and his revolutionary zeal.
Urban social movements present themselves as an answer to de3 ciencies of local politics. In this way, they situate themselves in agreement with popular diagnoses of crisis of democracy, and propose their own model of involvement in politics. However, is this model a chance for renewal of democracy, or is it just another version of politics understood as an enlightened management? Does it have the potential for broadening the political, or does it stop halfway? Presented article is an attempt in rethinking those questions. First part compares different political languages, in which critiques of contemporary democracy are formulated. Subsequently, Jacques Rancière’s conception is presented, as emphasising egalitarian and emancipatory dimensions of democracy. Examples of rhetorics and actions of urban social movements are considered in this double context of different political languages and radical character of democracy. The problem of ‘deficient political articulation’, which makes urban social movements unable to fully keep the promises they make, is stressed.
The aim of this article is to examine how family policies contribute to changes in family practices and towards gender equality in families. Empirically we draw on interviews with two groups of Polish-born parents: Polish parents who have migrated to Norway and Polish parents living in Poland. Norway and Poland are relevant cases for our exploration because they represent different types of welfare states, which have followed different paths towards their current family policy package. In our analysis of actual work–family adaptations we found a convergence towards gender-equal dual-earner/dual-carer arrangements in both groups, although there were differences in the level of agency. Polish parents in Poland felt less entitled to use the measures available to them, and sometimes refrained from using them, compared to Polish parents in Norway who expressed a strong sense of agency in using family policy measures to create a good life in Norway and as part of a project of change towards more gender-equal sharing of work and care responsibilities. The analysis confirms the strong link between family practices and family policies, but also illustrates how the effect of policies on practices may be hampered or boosted by the wider historical-cultural context of the society in question. In conclusion, in analyses of the link between policy and practice it may be fruitful to distinguish between family policy packages – the concrete set of entitlements for working parents – and family policy regimes, meaning policies in their wider context, including migrancy as a mediating factor.