A Comparison of Relaxations of Multiset Cannonical Correlation Analysis and Applications

Canonical correlation analysis is a statistical technique that is used to find relations between two sets of variables. An important extension in pattern analysis is to consider more than two sets of variables. This problem can be expressed as a quadratically constrained quadratic program (QCQP), commonly referred to Multi-set Canonical Correlation Analysis (MCCA). This is a non-convex problem and so greedy algorithms converge to local optima without any guarantees on global optimality. In this paper, we show that despite being highly structured, finding the optimal solution is NP-Hard. This motivates our relaxation of the QCQP to a semidefinite program (SDP). The SDP is convex, can be solved reasonably efficiently and comes with both absolute and output-sensitive approximation quality. In addition to theoretical guarantees, we do an extensive comparison of the QCQP method and the SDP relaxation on a variety of synthetic and real world data. Finally, we present two useful extensions: we incorporate kernel methods and computing multiple sets of canonical vectors

Geographical and temporal distribution of SARS-CoV-2 clades in the WHO European Region, January to June 2020

We show the distribution of severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) genetic clades over time and between countries and outline potential genomic surveillance objectives. We applied three genomic nomenclature systems to all sequence data from the World Health Organization European Region available until 10 July 2020. We highlight the importance of real-time sequencing and data dissemination in a pandemic situation, compare the nomenclatures and lay a foundation for future European genomic surveillance of SARS-CoV-2

From revolution to 'counter-revolution' : democracy in Central and Eastern Europe 30 years on

First published online: 02 July 2020The essay explains the origin, scope and forms of the anti-liberal surge taking place in Central and Eastern Europe. Why have voters across the region deserted the liberal politicians who managed to secure peace and prosperity on the ashes of communism? : Does the erosion of democratic values and institutions lead to autocracy, or something novel? : Special attention will be devoted to the issue of order and chaos in the broader European setting. Can order be maintained without shared values across EU member states? : The conclusions will point to the variety of hybrid regimes in Central and Eastern Europe and assess their impact

Introduction: The State of Democracy 20 Years on: Domestic and External Factors

The countries of East-Central Europe (ECE) embarked on a democratic transition in 1989 were proclaimed consolidated democracies when they joined the European Union (EU) in 2004. Today most of the new democracies are experiencing “democratic fatigue” and some seem vulnerable to an authoritarian turn. The EU, seen as the guarantor of the post-1989 democratic changes, is experiencing an unprecedented economic, financial, and democratic crisis with the combined challenges of technocracy and populism. The article explores the different approaches to the study of democracies in ECE, their specific features and vulnerabilities, and tries to provide an interpretation of the premature crisis of democracy in ECE in a broader transeuropean context

Democracy in Central and Eastern Europe:the State of the Art

The countries of East-Central Europe (ECE) embarked on a democratic transition in 1989 were proclaimed consolidated democracies when they joined the European Union (EU) in 2004. Today most of the new democracies are experiencing “democratic fatigue” and some seem vulnerable to an authoritarian turn. The EU, seen as the guarantor of the post-1989 democratic changes, is experiencing an unprecedented economic, financial, and democratic crisis with the combined challenges of technocracy and populism. The issue explores the different approaches to the study of democracies in ECE, their specific features and vulnerabilities, and tries to provide an interpretation of the premature crisis of democracy in ECE in a broader transeuropean context. (Résumé de l'éditeur

The road to the European Union.

1. The Czech and Sloval republics / ed. by Jacques Rupnik and Jan Zielonka2. Estonia, Latvia and Lithuania / ed. by Vello Pettai and Jan Zielonk