Challenges of Central European Security: Critical Insights

This book employs various theories of contemporary security studies to explore some of the most important and most common security issues in Central Europe at this time. Individual chapters of the book adhere mainly to European branches of critical and constructivist security studies, through which they look at some of the salient topics of Central European security politics.The distinction between internal and external security issues is employed throughout the book for analytical purposes.Tato kniha zkoumá za pomoci teorií současných bezpečnostních studií některé z nejdůležitějších bezpečnostních problémů dnešní střední Evropy. Jednotlivé její kapitoly vycházejí především z různých evropských kritických a konstruktivistických přístupů ke studiu bezpečnosti, které jsou následně aplikovány na charakteristická témata středoevropské bezpečnosti. Pro analytické účely kniha rozlišuje mezi vnitřními a vnějšími bezpečnostními tématy

Robuste log-ratio Methoden zur Klassifikation von hochdimensionalen Daten aus der Metabolomik

Abweichender Titel nach Übersetzung der Verfasserin/des VerfassersThe development of statistical methods which are able to deal with high-dimensional data belongs to the major research activities in statistics. In many fields (e.g. chemometrics, genomics, metabolomics) it is easy to measure and store data by using advanced modern techniques. Thus, there are also numerous real-world applications justifying these developments. One possible way how to deal with such data comes from the log-ratio point of view. There is whole branch of statistics devoted to log-ratios -- Compositional Data Analysis. Compositional data represent a special type of multivariate data which describe parts of a whole. In this context only relative information is important. Because of these special features of compositional data, the application of standard statistical methods could lead to invalid conclusions. The primary aim of the thesis is to introduce procedures for analysing high-dimensional data which originate from different groups. The main focus is set on applications in the field of metabolomics, where the different data groups consist of observations related to different diseases. The new methods should not only allow to differentiate between the groups, but they should also enable feature selection: only those features (variables), which allow to discriminate between the different groups, should be identified. An important request for these methods is their robustness against outlying observations, which is a common situation in real data. Another interest of the thesis is the investigation of outliers in the data. We focus on both observational outliers and on so-called cell outliers. The former refers to the situation when an observation deviates from the majority of a group in possibly all variables, while in the latter case for a certain observation only the values in some variables (cells) are deviating. This will contribute to gain a better insight into the data structure.11

Significance of variables for discrimination: Applied to the search of organic ions in mass spectra measured on cometary particles

International audienceThe instrument Cometary Secondary Ion Mass Analyzer (COSIMA) on board of the European Space Agency mission Rosetta to the comet 67P/Churyumov-Gerasimenko is a secondary ion mass spectrometer with a time-of-flight mass analyzer. It collected near the comet several thousand particles, imaged them, and analyzed the elemental and chemical compositions of their surfaces. In this study, variables have been generated from the spectral data covering the mass ranges of potential C-, H-, N-, and O-containing ions. The variable importance in binary discriminations between spectra measured on cometary particles and those measured on the target background has been estimated by the univariate t test and the multivariate methods discriminant partial least squares, random forest, and a robust method based on the log ratios of all variable pairs. The results confirm the presence of organic substances in cometary matter—probably a complex macromolecular mixture