• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 25
  • 3
  • Tagged with
  • 28
  • 13
  • 13
  • 13
  • 12
  • 12
  • 10
  • 10
  • 8
  • 6
  • 6
  • 5
  • 5
  • 5
  • 5
  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
11

Modelování disociační rekombinace lehkých iontů / Modeling the dissociative recombination of light ions

Hvizdoš, Dávid January 2021 (has links)
The purpose of this work and the project under which it was created is to develop, compare and validate several theoretical approaches and computation methods used to calculate the cross sections of dissociative recombination. For the most part it is con- cerned with the indirect dissociative recombination of molecular ions of H+ 2 in the singlet ungerade channels computed with three distinct approaches. First, the fully numerically solvable two-dimensional approach developed at ÚTF MFF UK as a part of my master's thesis. Second, a vibrational frame transformation method based on the work of Chang and Fano [E. S. Chang and U. Fano, Phys. Rev. A 6, 173 (1972)] and then enhanced into a full energy-dependent form by Gao and Greene [H. Gao and C. H. Greene, J. Chem. Phys. 91, 3988 (1989)], [H. Gao and C. H. Greene, Phys. Rev. A 42, 6946 (1990)], fur- ther improved by our own revisions. Third, a two-dimensional R-matrix method based on matching exact 2D solutions from a small interaction region to asymptotic solutions in the non-interacting region. We thoroughly discuss the various advantages and caveats of these methods and, in the later chapters, present our work on employing them for the realistic recombination of HeH+ + e− . Furthermore, we attempt to extend the presented models to the description of the...
12

Experimentální ověření stability kapalinových soustav / Experimental validation of stability of hydraulic systems

Petrůjová, Hana January 2015 (has links)
Dissertation thesis falls within the area of indoor climate and deals with a hydraulics of heating systems, mainly with the hydraulic separator. This earlier widely used element of the heating system, which hydraulically separates heat source and heat appliance, is nowadays in the heating systems based on condensation technologies inappropriate, as the results obtained from experimental measurements show. This findings also well correlate with own theoretical solution based on the calorimetric equation. Conclusion of the dissertation thesis shows fact that in case of imbalance flow rate between heat source and heat appliance adverse warming of return pipe water in the heating system with hydraulics separátor is caused. This effect in practice reduces the efficiency of heat production and expected condensation process of flue gas is discontinued.
13

Vliv ztráty hmoty hvězd na dynamiku hvězdokup / The influence of the stellar mass-loss on the dynamics of star clusters

Dinnbier, František January 2012 (has links)
This work aims at studying the influence of the stellar mass-loss, resulting from the stellar evolution, on the dynamics of massive star clusters. The emphasis has been put on the mass-loss by low-mass and intermediate-mass stars (m < 8 Mo) that form, at the end of their life, a planetary nebula. The expansion speed of gas released by these stars is lower than the escape speed from sufficiently massive star clusters, and the gas can be retained by the cluster. For modelling of the gas hydrodynamics, a simple sticky-particles method was used. To carry out simulations in which gaseous and stellar particles mutually interact through their gravity, substantial modifications had to be realized in the N-body codes Nbody6 and Hermit. For the sake of comparing the influence of stellar mass-loss and relaxation processes, which are happening in the simplified model, two types of simulations were performed: one with the formation of gaseous particles and the other consisting of purely stellar component. The simulations in which the gas component was present showed out a significantly different evolution in the central part of the cluster than those in which the presence of gas was not considered.
14

Aproximace maticemi malé hodnosti a jejich aplikace / Approximations by low-rank matrices and their applications

Outrata, Michal January 2018 (has links)
Consider the problem of solving a large system of linear algebraic equations, using the Krylov subspace methods. In order to find the solution efficiently, the system often needs to be preconditioned, i.e., transformed prior to the iterative scheme. A feature of the system that often enables fast solution with efficient preconditioners is the structural sparsity of the corresponding matrix. A recent development brought another and a slightly different phe- nomenon called the data sparsity. In contrast to the classical (structural) sparsity, the data sparsity refers to an uneven distribution of extractable information inside the matrix. In practice, the data sparsity of a matrix ty- pically means that its blocks can be successfully approximated by matrices of low rank. Naturally, this may significantly change the character of the numerical computations involving the matrix. The thesis focuses on finding ways to construct Cholesky-based preconditioners for the conjugate gradi- ent method to solve systems with symmetric and positive definite matrices, exploiting a combination of the data and structural sparsity. Methods to exploit the data sparsity are evolving very fast, influencing not only iterative solvers but direct solvers as well. Hierarchical schemes based on the data sparsity concepts can be derived...
15

Hodnocení výkonnosti podniku / Evaluation of Company Performance

Malinová, Lenka January 2012 (has links)
Diplomová práce se věnuje hodnocení výkonnosti podniku v letech 2007-2011. Za použití různých metod analýzy firmy a vhodných metod finanční analýzy je hodnocena výkonnost a finanční zdraví podniku. Výsledkem práce bude návrh možného postupu pro budoucí strategii.
16

Finanční analýza PFT, s.r.o. / Financial Analysis of PFT, Ltd

Lacková, Martina January 2013 (has links)
The financial situation of limited company PFT is evaluated in the period 2008 to 2013 through techniques of financial analysis. Then the resulting values are compared with the recommended values, sector averages and values of selected competing companies with limited liability. Multivariate methods of intercompany comparison are applied for a more comprehensive assessment of financial management. The conclusion is focused on summarizing the results, identifying strengths and weaknesses and proposing appropriate measures.
17

Analýza brzdění vozidla s nestandardním zásahem do brzdové soustavy / Analysis of Non-Standard Braking Intervention into the Brake System

Kortán, Daniel January 2017 (has links)
This master’s thesis focused on the issue of the possible conversion of liquid brake systems, in the form of replacement of wheel brakes. The first part focused on the function and description of the construction of different types of brakes. The second part is focused on description the types of brake system testing and the regulations regarding brake systems. The last part focused on the measurement of both vehicles and comparison of the results with the calculations.
18

Energetick a provozn­ optimalizace syst©mu veejn©ho osvÄtlen­ / Energy Optimization and Operation of Public Lighting

Houdek, Michal January 2010 (has links)
An objektive of this university graduation work is an essay about any possibilities for energy savings with operation optimalization of public lightings. Understandings and introduction operation problems of public lighting is devote in first part of this work. Here we can chapters as Importance of public lightings or Gulations and norms in ralation to public lightings. The bigist and special attention is concentrated to description to public lightings systems and it is basic components. Another main part of this work is demonstration of used systems that are leading to energy savings for public lightings. These problems are detailed and explained in chapter Regulation of public lighting systems. This graduation work is describing individual types of regulation with the systems that are used with these regulatios in systems of public lightings. The assignment of last part of graduation work was to make sample calculation of energy demand and calculatin of yearly consumption on exemplary temporary system of public lightings. For this occasion was extra special auxiliary application sytem set up inside the Microsoft Excel program where all individual calculations were done.
19

Uplatnění diagnostických metod na zařízeních paroplynového bloku / Application of diagnostic methods for devices of streem-gas blok

Hübková, Ivana January 2013 (has links)
This master´s thesis deals with problem of reliability of technical device in general a so there is explained bathtub curve, defects and malfunctions of devices and then there is a brief outline of reliability system. This thesis further briefly describes technical diagnostic and then there is performed the vibrodiagnostic measurements of selected pumps and ventilators in in heating plant Červený mlýn in Brno. Evaluation of their condition is done according to relevant standards. Further there was done a diagnostic of the steam traps through the ultrasound diagnostic. The last part of my thesis deals with the reliability of selected specific pumps in foregoing rating plant. There are showed reliability curves of selected pumps and elaboration of data from their long-term vibrations measurement.
20

Hodnocení finanční situace podniku a návrhy na její zlepšení / Evaluation of the Financial Situation in the Firm and Proposals to its Improvement

Simandl, Jakub January 2010 (has links)
This master’s thesis is located to the evaluation of the financial situation of the firm between 2005 and 2009. In this master´s thesis are used methods and indexes of financial analysis, based on results, in master´s thesis are defined suggestions for improvement of current situation.

Page generated in 0.0423 seconds