The aim of the study is to identify the recent local geodynamic processes on the territory of the Dniester PSPP (Ukraine), which arose as a result of the additional man-caused load during the construction of hydro-technical structures. The research is based on the results of 17 cycles of periodic static GNSS campaigns conducted during 2004-2017. In this work the vectors of horizontal displacement of the reference GNSS network points of Dniester PSPP are determined and their scheme is constructed. On the basis of average vectors of horizontal movement velocities during 2004-2017, the value of the velocities of dilatation - the parameter of Earth surface deformation which characterises the relative area expansion or compression, is calculated. As a result of the analysis of velocity distribution of the dilatation of Dniester PSPP territory, the areas of extreme values of compression and stretching are revealed, which testify to the increased geodynamic activity of the pivot part, as well as the main structures of the construction. and Savchyn Ihor, Vaskovets Serhii.
This paper presents examples of application of the method of local quasigeoid modelling based on the geophysical technique of gravity data inversion, using non-reduced surface gravity data and GNSS/levelling height anomalies. Its capacity is demonstrated with three examples consisting in computing detailed local quasigeoid models for three areas situated in Poland. The test areas are different in size (3,900, 23,000, 117,000 sq. kilometres), in geographic location as well as in density of the gravity data coverage. For each of the test regions, calculations were done in three variants, viz. without using any global geopotential model and with application of EGM96 and EGM08 models. The obtained results indicate that the applied method is suitable for creating high accuracy local quasigeoid models (the accuracies obtained were at the level of accuracy of GNSS/levelling test data)., Marek Trojanowicz., and Obsahuje bibliografii
The paper presents analysis relating to the method of local quasigeoid modelling based on the geophysical technique of gravity data inversion, using non-reduced surface gravity data and GNSS/levelling height anomalies. One of the main problems occurring in the application of the method is to determine the model weighting matrix, the purpose of which is to control the inversion process. This paper presents the analyses concerning the determination of certain constant coefficients signed as, and, appearing in the definition of the model weighting matrix. The calculations performed indicate that because of the accuracy of the density model, the coefficient should be in the range of 01. 0 001. 0, and the range 005.00025.0 should be adopted as the optimal. As the optimal values of the coefficients and, values 1.0 and 01.0, for the zones of constant density with area less than about 130 km2 were determined., Marek Trojanowicz., and Obsahuje bibliografické odkazy
In October 2005 local seismic monitoring started in the area of the Hronov-Poříčí Fault Zone. In the present paper we summarize seismic measurements using a small-aperture seismic array Ostaš. Parameters of the array and methodology of the data registration and processing are described. The list of local microearthquakes during two years of registration is presented., Jiří Málek, Milan Brož, Vladimír Stejskal and Jaroslav Štrunc., and Obsahuje bibliografické odkazy
We propose a new localization result for the leading eigenvalue and eigenvector of a symmetric matrix A. The result exploits the Frobenius inner product between A and a given rank-one landmark matrix X. Different choices for X may be used, depending on the problem under investigation. In particular, we show that the choice where X is the all-ones matrix allows to estimate the signature of the leading eigenvector of A, generalizing previous results on Perron-Frobenius properties of matrices with some negative entries. As another application we consider the problem of community detection in graphs and networks. The problem is solved by means of modularity-based spectral techniques, following the ideas pioneered by Miroslav Fiedler in mid-’70s. We show that a suitable choice of X can be used to provide new quality guarantees of those techniques, when the network follows a stochastic block model., Dario Fasino, Francesco Tudisco., and Obsahuje seznam literatury
This paper discusses a simple logical approach to solving Sudoku puzzles, which may be interpreted as a mental model of the puzzle. The model employs an auxiliary matrix 9x9, which is formed from the matrix specifying initial given values of the puzzle in such a way that its empty squares are filled by lists of candidate values. These lists are determined by initial values together with the puzzle constraints: each column/row/subarea 3x3 is occupied by integers 1, 2, ..., 9 appearing only once. Applying the simple logical rules such as if..., then..., this auxiliary matrix is subsequently simplified in such a way that we reduce the set of alternative possibilities, where in a final stage each position of auxiliary matrix is occupied just by one integer from {1,2,...,9} and the resulting matrix satisfies the above mentioned constraints. The logical rules used may be hierarchically arranged in a sequence of increasing complexity of their preceding parts. Therefore, Sudoku puzzles may be classified according to the complexity of their solution; from the simplest puzzles to the most complex by using the rules and a back-track search., V práci je diskutovaný jednoduchý logický prístup k riešeniu hry Sudoku, ktorý môže byť taktiež interpretovaný ako mentálny model tejto hry. Použitý model využíva pracovnú maticu 9x9, ktorá je vytvorená z matice špecifikujúcej počiatočnú pozíciu hry tak, že prázdne pozície sú zaplnené alternatívnymi možnosťami určenými z počiatočnej pozície pomocou podmienok tak, aby každý riadok/stĺpec/oblasť 3x3 obsahoval čísla 1, 2, ..., 9 prave raz. Použitím jednoduchých logických pravidiel typu if..., then... túto pracovnú maticu postupne zjednodušíme tak, že redukujeme výskyt alternatívnych možností, až v konečnej fáze úpravy matice v každej pozícii máme práve jedno číslo, pričom táto výsledná matica vyhovuje vyššie uvedeným podmienkam. Použité logické pravidlá pre zjednodušenie Sudoku môžu byť hierarchicky usporiadané podl'a rastúcej zložitosti ich podmienky (antecedentu). Potom hry Sudoku môžu byť klasifikované podl'a zložitosti ich riešenia; od jednoduchých hier až po vel'mi zložité (diabolské), kde je potrebné použiť pravidlá, ktoré vo svojich podmienkach obsahujú spätné prehl'adávanie pracovnej matice., Vladimír Kvasnička, Michal Cádrik., and Obsahuje bibliografii
The aim of this study was a comparison of risk stratification for death in patients after myocardial infarction (MI) and of risk stratification for malignant arrhythmias in patients with implantable cardioverter-defibrillator (ICD). The individual risk factors and more complex approaches were used, which take into account that a borderline between a risky and non-risky value of each predictor is not clear-cut (fuzzification of a critical value) and that individual risk factors have different weight (area under receiver operating curve - AUC or Sommers´ D - Dxy). The risk factors were baroreflex sensitivity, ejection fraction and the number of ventricular premature complexes/hour on Holter monitoring. Those factors were evaluated separately and they were involved into logit model and fuzzy models (Fuzzy, Fuzzy-AUC, and Fuzzy-Dxy). Two groups of patients were examined: a) 308 patients 7-21 days after MI (23 patients died within period of 24 month); b) 53 patients with left ventricular dysfunction examined before implantation of ICD (7 patients with malignant arrhythmia and electric discharge within 11 month after implantation). Our results obtained in MI patients demonstrated that the application of logit and fuzzy models was superior over the risk stratification based on algorithm where the decision making is dependent on one parameter. In patients with implanted defibrillator only logit method yielded statistically significant result, but its reliability was doubtful because all other tests were statistically insignificant. We recommend evaluating the data not only by tests based on logit model but also by tests based on fuzzy models., P. Honzík ... [et al.]., and Obsahuje bibliografii a bibliografické odkazy
This paper is devoted to a complex review of various monitoring networks operating in the eastern part of the Ostrava- Karviná Coal Basin. In the first place, there were systems for monitoring seismo acoustic emissions during coal extraction. Later a local seismic network was installed which encompasses pa rtial arrays of seismic stati ons located in the individual mines underground. In addition, a special regional seismic network was established in order to ensure reasonable recordings of strong seismic events observed in this area. In 2001 an array was constructed with up to five surface seismic stations which monitor manifestations of rockbursts due to imposed dynamic loading on existing buildings at selected sites. Recently, a quite new monitoring system of accelerometers began operating, the purpose of which is to check the effects of rockbursts on surface structures. Using the output data of all monitoring systems, different graphs were constructed, which can faciliate geophysical interpretation of geodynamic processes in mines., Karel Holub, Josef Holečko, Jana Rušajová and Anna Dombková., and Obsahuje bibliografické odkazy