We study some geometric properties associated with the t-geometric means A ♯_{t} B:= A^{1/2}(A^{-1/2}BA^{-1/2})^{t} A^{1/2}of two n × n positive definite matrices A and B. Some geodesical convexity results with respect to the Riemannian structure of the n × n positive definite matrices are obtained. Several norm inequalities with geometric mean are obtained. In particular, we generalize a recent result of Audenaert (2015). Numerical counterexamples are given for some inequality questions. A conjecture on the geometric mean inequality regarding m pairs of positive definite matrices is posted., Trung Hoa Dinh, Sima Ahsani, Tin-Yau Tam., and Obsahuje seznam literatury
To investigate the geodynamic pattern of the Bohemian Massif in Central Europe, the GEONAS network of permanent GNSS stations was established. It now consists of 18 stations, recorded both the NAVSTAR and GLONASS positional signals; they are located along the tectonic zones of the Massif in order to monitor any movement activities. Yet other stations are still planned to be built, and some recent stations are to be moved within these active areas to increase their local distribution density. The GNSS data are processed by the use of Bernese GPS software 5.0. The time series of station positions give fundamental information for both regional and local geodynamic studies. The GEONAS network covers an area of 400 by 220 km, and it allows the effects of dynamic processes going on inside the Earth’s crust, as well as the upper lithosphere to be monitored. A few examples of geodynamic interpretations are presented here., Vladimír Schenk, Zdeňka Schenková, Milada Cajthamlová and Zdeněk Fučík., and Obsahuje bibliografii
The aim of presented research was to rec ognize a fine geological structure of post-glacial sedimentary forms. The survey was conducted in the South Pomeranian Lake District (north - western Poland) in the vicinity of Pile Lake and Strzeszyn Lake. The geoelectrical equipment Terrameter SAS 4000 (ABEM) with LUND Imaging System was used for the measurements of apparent resistivity of rock mass. The resistivity imaging was carried out im plementing Schlumberger S-protocol with 41 electrodes. Research was done along profiles crossing a border between two sedimentary forms. It allowed to recognize and compare the layered structures of the different post - glacial deposits down to 70 meters be low the surface. The data were interpreted on the base of two-dimensional inversion methods. Results were corre lated and compared with geological dat a accessible in the literature concerning of the research area. Geophysical prospecting gave good results and allowed to recognize a fine geological structure of the deposits., Adam F. Idziak and Anna Wysowska-Świebodzińska., and Obsahuje bibliografické odkazy
Portrét amerického fyzika, který získal v r. 2009 Nobelovu cenu za vynález zobrazovacího polovodičového obvodu - CCD senzoru. and Rubrika: Nobelova cena za fyziku
Získat Nobelovu cenu je událost, která změní život. Bod zlomu. Mnoho lidí chce vědět, jak toho laureát dosáhl, a také se po něm žádá, aby dodal svůj životopis. To všechno a události provázející udělení Nobelovy ceny způsobí, že se každý z nás zamyslí nad svým životem, zavzpomíná a pokusí se vystihnout všechny události, které ho dovedly až do přítomnosti., George F. Smoot ; přeložil Ivan Gregora., and přeloženo z angličtiny