Hledání extrasolárních planet je poměrně mladým a velmi rychle se rozvíjejícím odvětvím astronomie. Od prvního objevu roku 1995 bylo nalezeno 117 extrasolárních planet a řádově stovky hnědých trpaslíků. Současná teorie vzniku planet z protoplanetárních disků ukazuje, že vznik planet není ve vesmíru ničím výjimečným, zároveň však mnohé objevy extrasolárních planet naznačují, že tato teorie má doposud značné mezery. Planety mohou vznikat i přímou fragmentací zárodečného oblaku vlivem gravitačních nestabilit. Stručně jsou shrnuty základní poznatky o vzniku a vývoji planetárních systémů a hnědých trpaslíků, je uveden popis nejpoužívanějších detekčních metod., Jakub Rozehnal., and Obsahuje seznam literatury
The (extraterritorial) application of US antitrust laws can have, for the concerned European companies, serious consequences. This applies to the prosecution of antitrust violations as criminal offenses, resulting to the imposition of prison sentences against competitors responsible for antitrust infringing (including foreigners), on the other hand the specificities of bringing civil claims for damages before US courts, including procedural aspects. This article provides a summary of the extraterritorial application of US antitrust law, with emphasis to the jurisdiction of US courts. A question whether the European Commission has jurisdiction over conduct that occurs outside the EU and the differing approaches of the US and the EU of how to regulate foreign anticompetitive activity will be examined., Rastislav Funta., and Obsahuje bibliografické odkazy
We give a new proof of Beurling’s result related to the equality of the extremal length and the Dirichlet integral of solution of a mixed Dirichlet-Neuman problem. Our approach is influenced by Gehring’s work in $\mathbb{R}^3$ space. Also, some generalizations of Gehring’s result are presented.
Sharp bounds on some distance-based graph invariants of n-vertex k-trees are established in a unified approach, which may be viewed as the weighted Wiener index or weighted Harary index. The main techniques used in this paper are graph transformations and mathematical induction. Our results demonstrate that among k-trees with n vertices the extremal graphs with the maximal and the second maximal reciprocal sum-degree distance are coincident with graphs having the maximal and the second maximal reciprocal product-degree distance (and similarly, the extremal graphs with the minimal and the second minimal degree distance are coincident with graphs having the minimal and the second minimal eccentricity distance sum).
In this paper we study semilinear second order differential inclusions involving a multivalued maximal monotone operator. Using notions and techniques from the nonlinear operator theory and from multivalued analysis, we obtain “extremal” solutions and we prove a strong relaxation theorem.
In this paper we study some properties of the distribution function of the random variable C(X,Y) when the copula of the random pair (X,Y) is M (respectively, W) - the copula for which each of X and Y is almost surely an increasing (respectively, decreasing) function of the other -, and C is any copula. We also study the distribution functions of M(X,Y) and W(X,Y) given that the joint distribution function of the random variables X and Y is any copula.
For two vertices $u$ and $v$ of a graph $G$, the closed interval $I[u, v]$ consists of $u$, $v$, and all vertices lying in some $u\text{--}v$ geodesic of $G$, while for $S \subseteq V(G)$, the set $I[S]$ is the union of all sets $I[u, v]$ for $u, v \in S$. A set $S$ of vertices of $G$ for which $I[S]=V(G)$ is a geodetic set for $G$, and the minimum cardinality of a geodetic set is the geodetic number $g(G)$. A vertex $v$ in $G$ is an extreme vertex if the subgraph induced by its neighborhood is complete. The number of extreme vertices in $G$ is its extreme order $\mathop {\mathrm ex}(G)$. A graph $G$ is an extreme geodesic graph if $g(G) = \mathop {\mathrm ex}(G)$, that is, if every vertex lies on a $u\text{--}v$ geodesic for some pair $u$, $ v$ of extreme vertices. It is shown that every pair $a$, $ b$ of integers with $0 \le a \le b$ is realizable as the extreme order and geodetic number, respectively, of some graph. For positive integers $r, d,$ and $k \ge 2$, it is shown that there exists an extreme geodesic graph $G$ of radius $r$, diameter $d$, and geodetic number $k$. Also, for integers $n$, $ d, $ and $k$ with $2 \le d < n$, $2 \le k < n$, and $n -d - k +1 \ge 0$, there exists a connected extreme geodesic graph $G$ of order $n$, diameter $d$, and geodetic number $k$. We show that every graph of order $n$ with geodetic number $n-1$ is an extreme geodesic graph. On the other hand, for every pair $k$, $ n$ of integers with
$2 \le k \le n-2$, there exists a connected graph of order $n$ with geodetic number $k$ that is not an extreme geodesic graph.
The aim of the paper is to discuss the extreme points of subordination and weak subordination families of harmonic mappings. Several necessary conditions and sufficient conditions for harmonic mappings to be extreme points of the corresponding families are established.
We characterize linear operators that preserve sets of matrix ordered pairs which satisfy extreme properties with respect to maximal column rank inequalities of matrix sums over semirings.
During the solar cycle minimum period, a period of a suddenly enhanced solar activity occurred in early February 198d. Two proton flares were observed during this period after a long period of a totally quiet solar activity (R = 0 on most days in the second half of December and in January). Other flares, various phenomena
accompanying proton flares, like type II and type IV radio bursts and a large Forbush deerease of cosmic ray intensity were observed as well as an extremely severe geomagnotic storm (Kp = 9) and strong disturbances in the Earth´s ionosphere (SIDs and ionospheric storm), Czechoslovak solar and geophysical observations for this period are presented and interpreted with the use of other observations. Special attention is given to the flares of February 4 (start 0732 and 1025 UT) and February 5 (start 0934 UT) because spectrohelioscopic observations from the Hurbanovo observatory are available for these events.