Migration research is an emerging field in the Czech Republic and data collection poses many methodological challenges. Some of the problems are universal for the research of other hard-to-reach populations. Other problems are, on the contrary, unique, applying only for the research of immigrants and could be country specific. This article focusses mainly on the quantitative research of immigrants where the issue of sampling problem is of major concern. The aim of the article is to address the issue of sampling immigrants in the context of the Czech Republic. In the first part of the article, there is a review of existing methodological approaches to researching immigrant populations. The focus here is on potential problems when applying particular methods in the Czech context. The second part of the article is dedicated to a review of four major Czech sample surveys of immigrants that are compared in terms of their methodology and basic results., Josef Bernard, Yana Leontiyeva., and Obsahuje bibliografii
This paper investigates the non-fragile state estimation problem for a class of discrete-time T-S fuzzy systems with time-delays and multiple missing measurements under event-triggered mechanism. First of all, the plant is subject to the time-varying delays and the stochastic disturbances. Next, a random white sequence, the element of which obeys a general probabilistic distribution defined on [0,1], is utilized to formulate the occurrence of the missing measurements. Also, an event generator function is employed to regulate the transmission of data to save the precious energy. Then, a non-fragile state estimator is constructed to reflect the randomly occurring gain variations in the implementing process. By means of the Lyapunov-Krasovskii functional, the desired sufficient conditions are obtained such that the Takagi-Sugeno (T-S) fuzzy estimation error system is exponentially ultimately bounded in the mean square. And then the upper bound is minimized via the robust optimization technique and the estimator gain matrices can be calculated. Finally, a simulation example is utilized to demonstrate the effectiveness of the state estimation scheme proposed in this paper.
This article focuses on a comparison of attitudes towards migration in twenty European countries. It analyses data from the European Social Survey 2002. The first part of the article contains a summary of the available sources of data on migration and a brief outline of developments and the current state of migration in Europe. The second part looks at the question of whether attitudes towards immigrants are related to the numbers and structure of immigrants in a country and their economic situation. Three thematic areas are examined: 1) the host population's willingness to accept immigrants; 2) perceptions of the impact of immigration on the host country; 3) attitudes towards different forms of integration of immigrants. The findings indicate that Europeans are more willing to accept migrants that are of the same race (ethnic group) and from Europe than they are migrants of a different race (ethnic group) and from states outside Europe. The strongest unwillingness to accept people from other states and the strongest emphasis on the negative impact of immigration was observed in Greece and Hungary, while the strongest willingness to accept immigrants was found in Sweden and Switzerland and was connected with a more positive perception of the impact of immigration.