The aim of the paper is to investigate the structure of disjoint iteration groups on the unit circle ${\mathbb{S}^1}$, that is, families ${\mathcal F}=\lbrace F^{v}\:{\mathbb{S}^1}\longrightarrow {\mathbb{S}^1}\; v\in V\rbrace $ of homeomorphisms such that
\[ F^{v_{1}}\circ F^{v_{2}}=F^{v_{1}+v_{2}},\quad v_1, v_2\in V, \] and each $F^{v}$ either is the identity mapping or has no fixed point ($(V, +)$ is an arbitrary $2$-divisible nontrivial (i.e., $\mathop {\mathrm card}V>1$) abelian group).
In this paper we study some special residuated lattices, namely, idempotent residuated chains. After giving some properties of Green's relation $\mathcal D$ on the monoid reduct of an idempotent residuated chain, we establish a structure theorem for idempotent residuated chains. As an application, we give necessary and sufficient conditions for a band with an identity to be the monoid reduct of some idempotent residuated chain. Finally, based on the structure theorem for idempotent residuated chains, we obtain some characterizations of subdirectly irreducible, simple and strictly simple idempotent residuated chains.
The structure of the unit group of the group algebra of the group $A_4$ over any finite field of characteristic 2 is established in terms of split extensions of cyclic groups.
We give some necessary and sufficient conditions for transitive $l$-permutation groups to be $2$-transitive. We also discuss primitive components and give necessary and sufficient conditions for transitive $l$-permutation groups to be normal-valued.
The problem addressed in this paper is the reconstruction of an object in the form of a realistically textured 3D model from images taken with an uncalibrated camera. We especially focus on reconstructions from {\em short} image sequences. By means of a description of an easy to use system, which is able to accomplish this in a fast and reliable way, we give a survey of all steps of the reconstruction pipeline. For the purpose of developing a coherent reconstruction system it is necessary to integrate a number of different techniques such as feature detection, algorithms of the RANSAC-family, and methods for auto-calibration. We describe and review recent developments of distinct strands of these techniques. While developing our system the necessity of improvements of several steps of the state-of-the-art reconstruction pipeline emerged. Two of these innovations are introduced in detail in this paper: an advanced SIFT-based feature detector and a two-stage RANSAC process facilitating a faster selection of relevant object points. In addition, we give a recommendation regarding auto-calibration for short image sequences.
To verify possibilities of the thermic sinking technology the experiments with magmatic rocks (muscovite-biotite granite, amphibole-pyroxene andesite, pyroxene basalt) were made in the preliminary research phase. The contribution presents the microscopic study results of petrographic and structural observations of the rocks after their thermic reworking. Mainly distribution of melted rocks in the form of glass, forming of brittle deformations (fractures) on the level of mineral and rock, and penetration of melt into fissures were observed., Roman Farkašovský and Michal Zacharov., and Obsahuje bibliografii
This paper presents the relation between main crack systems and physical properties of carbonate rocks. The existence of cracks in a rock mass causes the reduction of seismic wave velocity, which is smaller in direction perpendicular to a crack plane than in direction parallel to it. This affects the occurrence of the anisotropy of seismic wave velocity, which is characteristic for rocks with preferred orientation of cracks. The existence of relationship between crack and seismic anisotropy allowed to use geophysical methods for determination of fracture density and orientation of crack systems. The research area is located in the south-east part of the Upper Silesian Trough. Tectonic observation and geophysical measurements was carried on the carbonate sequence on the both fold limbs building the Chrzanow-Wilkoszyn Syncline, originated during the Early Cimmerian movements, in the Upper Triassic - Middle Jurassic period. It was measured seismic waves velocity in the surface layers of rock mass and the strike azimuth and dip angle of cracks.The seismic anisotropy of the rock mass was done along radial profiles having common central point using P.A.S.I. Seis mograph (Mod.16S24-N). Results of field measurements were interpreted to estimate components of crack and velocity tensors. Obtained outcomes allowed to compare the existing main crack systems on the both fold limbs with seismic measurements. Eventually we have shown that seismic measurements are useful tool to study the cracks anisotropy in rocks inaccessible for direct observations., Iwona Stan-Kleczek, Katarzyna Sutkowska, Dominika Stan and Mikołaj Zolich., and Obsahuje bibliografické odkazy
Recently, Baczyński et al. (2017) proposed a new family of implication operators called semicopula based implications, which combines a given a priori fuzzy implication and a semicopula. In this paper, firstly, the relationship between the basic properties of the priori fuzzy implication and the semicopula based implication are analyzed. Secondly, the conditions such that the semicopula based implication is a fuzzy implication are studied, the study is carried out mainly in the case that the semicopula is a special family semicopula and the priori fuzzy implication is a (U,N)-implication. Moreover, the case that the semicopula based implication is 2-increasing (directionally decreasing, respectively) is also considered.
The transformed C6 glial cells in cultures were treated with sodium mercaptoborate (Na2B12H11SH, BSH), a carrier of atomic targets (10B) of thermal neutrons for the neutron capture therapy of brain tumors. As shown by light microscopy, the therapeutic dose of BSH (100 µg/ml) did not alter the gross morphology and growth of the population of cells within a 72 h treatment interval. Electron microscopic analysis of these cells revealed activation of nucleoli and, occasionally, enlarged and bifurcated mitochondria. After 200 µg BSH/ml and 72 h treatment, growth of the cell population was inhibited and ultrastructural changes became more profound. They included condensation of chromatin and its allocation to the nuclear envelope which formed deeper invaginations. Mitochondria further increased in size and were characterized by slim or angular cristae. Moreover, in circumscribed segments of some of the slightly swollen mitochondria their cristae disappeared or were reduced to fine pouch-like structures localized near the continuous outer membrane, suggestive for a non-destructive restructuring of the inner mitochondrial membrane. The smooth pinocytotic vesicles near the plasma membrane, lysosomes and heterogeneous dense bodies were more frequent. The revealed subcellular targets of BSH may initiate the development of pharmacological protocols aimed to further improve the tolerance to BSH by the healthy tissues of patients undergoing BNCT of brain tumors, e.g. by intervention into the oxidative stress triggered likely by the altered mitochondria., V. Mareš, D. Krajčí, V. Lisá., and Obsahuje bibliografii
This paper aims to present and discuss the concept of a subjective job scheduler with a satisfying criterion based on a Backpropagation Neural Network (BPNN) and a greedy task alignment procedure. The BPNN is to assign priorities to the tasks of each job based on the given subjective criteria. The subjective criteria and the task alignment procedure depend on the solution plan towards a given job scheduling problem depending on the user's need. When the scheduler is provided with a desired job selection criteria and task alignment procedure for the problem, it generates user satisfying solutions for a set of jobs. The satisfying criterion of the scheduler determines the user satisfaction based on three measures: convergence test of the BPNN, validity of the input job set and cost evaluation of the solutions. The simulations and comparisons presented in this paper indicate that the proposed approach is one of the most effective strategies of structuring a subjective functional job scheduler.