Job Scheduling in Computational Grids is gaining importance due to the need for efficient large-scale Grid-enabled applications. Among different optimization techniques designed for the problem, Genetic Algorithm (GA) is a popular class of solution methods. As GAs are high level algorithms, specific algorithms can be designed by choosing the genetic operators as well as the evolutionary strategies such as Steady State GAs and Struggle GAs. In this paper we focus on Struggle GAs and their tuning for scheduling of independent jobs in computational grids. Our results showed that a careful hash implementation for computing the similarity of solutions was able to alleviate the computational burden of Struggle GA and perform better than standard similarity measures. This is particularly interesting for the scheduling problem in Grid systems, which due to changeability over time, has demanding time restrictions on the computation of planning the jobs to resources.
99. svazek Divadelní knihovny Máje obsahuje překlad Gozziho Turandot s odkazem na herecké obsazení hry, která byla uvedena v Národním divadle se Zdenkou Baldovou v hlavní roli. Hra, jejíž děj se odehrává v Číně, je jedním z komedie dell´arte. DIFI-DIGI-04
The study presents experimental investigations of spatial turbulence intensity and scales of turbulent eddies (macroeddies) in a rectangular channel and the impact of the hydraulic jump on their vertical and streamwise distributions over a flat and scoured bed. The results of four tests and two different discharge rates are presented. Intensive mixing caused by the hydraulic jump has an impact on the instantaneous velocity, turbulence intensity and sizes of macroeddies, as well as their vertical and longitudinal distributions along the channel. The largest differences in turbulence characteristics were reported directly after the hydraulic jump, above the eroded bed. The interaction between the stream of the increased turbulence and the bed is a direct cause of formation of scour downstream water structures, which has a great effect on overall flow characteristics. The scour hole that arose downstream the jump moderated, in a small degree, the turbulence intensity at its end. Just next to the hydraulic jump only the small longitudinal relative sizes of macroeddies were present, while at the end of the analyzed reach, downstream of the scour, the relative scale reached around 1.5 depth of the stream.
Summary: In the present paper indications have been presented that:
(1) Kernels with tangled magnetic lines of force occur in solar flares.
(2) Random (turbulent) motions occur in hot flare plasma.
(3) A MHD turbulence can explain huge flare energy release (plasma heating. electron and proton acceleration).
(4) It has been also shown that a MHD turbulence can efficiently develop in a strong magnetic field in the solar corona.
On this basis it is suggested that the MHD turbulence is Ihe basic mechanism of the flare energy release.