Pokrok, který přineslo 20. století v exaktních vědách, se druhotně projevil také v archeologii. Snaha poznat aspekty vývoje společnosti z pohledu, který nepostihly písemné prameny, vedla k těsné spolupráci s přírodovědnými a technickými obory při řešení otázek v rámci záchrany a rekonstrukce malostranské rotundy sv. Václava na Matematicko-fyzikální fakultě Univerzity Karlovy., The progress made in exact sciences in the 20th century is also evident in archaeology. The effort to grasp aspects of society’s development from a point untouched by written sources has led to a close cooperation between natural-scientific and technical disciplines during the preservation and restoration of St. Wenceslas Rotunda at the Faculty of Mathematics and Physics, Charles University., Jarmila Čiháková, Martin Vlach, Luboš Veverka, Ilona Vlachová, Ivo Světlík., and Obsahuje bibliografické odkazy
The well known types of routes in graphs and directed graphs, such as walks, trails, paths, and induced paths, are characterized using axioms on vertex sequences. Thus non-graphic characterizations of the various types of routes are obtained.
A computationally simple method for generating reduced-order models that minimise the L2 norm of the approximation error while preserving a number of second-order information indices as well as the steady-state value of the step response, is presented. The method exploits the energy-conservation property peculiar to the Routh reduction method and the interpolation property of the L2-optimal approximation. Two examples taken from the relevant literature show that the suggested techniques may lead to approximations that are not worse than those afforded by popular more cumbersome techniques.
Exercise stimulates increases in heart rate (HR), stroke volume (SV) and cardiac output (CO). These adaptive mechanisms are strongly dependent on the type of exercise. Both rowing and cycling are widely used for physical training worldwide; however, evidence regarding the differences in major hemodynamic parameters during rowing and cycling remains insufficient. Ten healthy male volunteers were randomly assigned to perform either a rowing or cycling exercise. After 20 min rest, the group who had rowed first performed the cycling exercise and vice versa. Exercise was performed at a power-to-weight ratio of 2 W/kg for 2 min. HR, SV, CO and blood pressure (BP) were measured noninvasively using pulse-wave analysis at baseline and immediately after each exercise. HR, SV and CO were significantly higher after exercise than at rest. Whereas HR was comparable between rowing and cycling, SV and CO were significantly higher after rowing than after cycling. BP was comparable among all three measurements. Rowing increased SV and CO to a greater extent than cycling, whereas HR and BP were not influenced by the type of exercise. Our data suggest that rowing leads to more extensive stimulation of cardiac contractility and/or decreases in peripheral vascular resistance compared with cycling., P. Horn, P. Ostadal, B. Ostadal., and Obsahuje bibliografii