Václav Snásel

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Graphic processing units (GPUs) emerged recently as an exciting new hardware environment for a truly parallel implementation and execution of Nature and Bio-inspired Algorithms with excellent price-to-power ratio. In contrast to common multicore CPUs that contain up to tens of independent cores, the GPUs represent a massively parallel single-instruction(More)
In this paper we introduce the Pivoting M-tree (PM-tree), a metric access method combining M-tree with the pivot-based approach. While in M-tree a metric region is represented by a hyper-sphere, in PM-tree the shape of a metric region is determined by intersection of the hyper-sphere and a set of hyper-rings. The set of hyper-rings for each metric region is(More)
In multi-dimensional databases the essential tool for accessing data is the range query (or window query). In this paper we introduce a new algorithm of processing range query in universal B-tree (UB-tree), which is an index structure for searching in multi-dimensional databases. The new range query algorithm (called the DRU algorithm) works efficiently,(More)
Scheduling is one of the core steps to efficientlyexploit the capabilities of heterogeneous distributedcomputing systems and is an NP-complete problem.Therefore using meta-heuristic algorithms is asuitable approach in order to cope with its difficulty.In meta-heuristic algorithms, generating individualsin the initial step has an important effect on(More)
Fuzzy sets and fuzzy logic can be used for efficient data classification by fuzzy rules and fuzzy classifiers. This paper presents an application of genetic programming to the evolution of fuzzy classifiers based on extended Boolean queries. Extended Boolean queries are well known concept in the area of fuzzy information retrieval. An extended Boolean query(More)
Scheduling is one of the core steps to efficiently exploit the capabilities of emergent computational systems such as grid. Grid environment is a dynamic, heterogeneous and unpredictable one sharing different services among many different users. Because of heterogeneous and dynamic nature of grid, the methods used in traditional systems could not be applied(More)
The wide spread use of computer networks in today's society, especially the sudden surge in importance of the World Wide Web, has made computer network security an international priority. Since it is not technically feasible to build a system with no vulnerabilities, intrusion detection (ID) has become an important area for researches. An intrusion that(More)
The column subset selection problem is a well-known hard optimization problem of selecting an optimal subset of k columns from the matrix A<sup>m&#x00D7;n</sup>, k&lt;; n, so that the cost function is minimized. The problem is of practical importance for data mining and processing since it can be used for unsupervised feature selection, dimension reduction,(More)