Abstract-Imbalance in data classification is a frequently discussed problem that is not well handled by classical classification techniques. The problem we tackled was to learn binary classification model from large data with accuracy constraint for the minority class. We propose a new meta-learning method that creates initial models using cost-sensitive learning by logistic regression and uses these models as initial chromosomes for genetic algorithm. The method has been successfully tested on a large real-world data set from our internet security research. Experiments prove that our method always leads to better results than usage of logistic regression or genetic algorithm alone. Moreover, this method produces easily understandable classification model.

Mining sequential patterns is an important problem in the field of data mining and many algorithms and optimization techniques have been published to deal with that problem. The GSP algorithm, which is one of them, can be used for mining sequential patterns with some additional constraints. In this paper, we propose a new algorithm for mining multi-level sequential patterns based on GSP. The idea is that if a more general item appears in a pattern, the pattern has higher or at least the same support as the one containing the corresponding specific item. However, too generalized sequence patterns are not important for user. In our algorithm generalization uses a selective method based on information content of patterns. This allows us to mine more patterns with the same minimal support threshold and to reveal new potentially useful patterns.

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In the modern decision-making practice of the Office for the Protection of Competition, the exemption from the prohibition of anticompetitive agreements pursuant to Section 3(4) of the Act on the Protection of Competition and Article 101 (3) of the Treaty on the Functioning of the European Union is not applied. This paper aims to analyze the decision-making practice that relates to these provisions and to assess the quality of the stated reasons, why the Office did not apply this exemption in individual cases. For these purposes, it is necessary to theoretically analyze the conditions for the application of the exception. Subsequently, the most frequently used arguments for not using the exception in decision-making practice are identified and their suitability in the theoretical context is examined.

Professor Josef Bejček spent a large part of his academic career with PrF MU. We are honoured to be able to publish a publication on his birthday.