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  • 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.
151

Temperace a chlazení vstřikovacího nástroje

MACHO, Michal January 2018 (has links)
This diploma thesis deals with the design of injection molds, especially it is focused on their temperance and cooling. The aim is to design a beneficial technological process for tempering and cooling the injection mold for critically exposed sites. In the theoretical part I focused on a comprehensive outline of the issue of injection molding and the possibility of tempering and cooling circuits. In the practical part the specified injection was modeled and an injection mold was designed for its implementation. The construction was carried out in the Siemens NX program and the simulation analysis was done in Cadmould 3D - F and Aeroflow software. For the POM material the total shrinkage and warpage of 1.674 [mm] and the flatness of the hem of 0.403 [mm] at a total optimum mold temperature of 80 [°C.] were achieved. For PA material were total shrinkage and warpage 1,745 [mm] and flatness of hem 1,649 [mm]. I researched that the maximum mold temperature at POM injection is 94.862 [° C] and the end temperature at the end of the cycle is 87.259 [°C] at a critical point. The main finding is the possibility to affect the overall shrinkage and warpage along with the flatness of the hem by varying the temperature of the cooling circuits. Based on the detected data, the active cooling circuit is more suitable for installation than the passive cooling element. The results of this work enable shortening of the technological cycle time of the injection mold and selecting of a suitable cooling solution for exposed injection sites.
152

Nehomogenní Poissonův proces - odhadování a simulace / Non-homogeneous Poisson process - estimation and simulation

Vedyushenko, Anna January 2018 (has links)
This thesis covers non-homogeneous Poisson processes along with estimation of the intensity (rate) function and some selected simulation methods. In Chapter 1 the main properties of a non-homogeneous Poisson process are summarized. The main focus of Chapter 2 is the general maximum likelihood estimation procedure adjusted to a non-homogeneous Poisson process, together with some recommen- dations about calculation of the initial estimates of the intensity function param- eters. In Chapter 3 some general simulation methods as well as the methods designed specially for log linear and log quadratic rate functions are discussed. Chapter 4 contains the application of the described estimation and simulation methods on real data from non-life insurance. Furthermore, the considered sim- ulation methods are compared with respect to their time efficiency and accuracy of the simulations. 1
153

Efektivní trasování cest v objemových médiích na GPU / Efficient GPU path tracing in solid volumetric media

Forti, Federico January 2018 (has links)
Realistic Image synthesis, usually, requires long computations and the simulation of the light interacting with a virtual scene. One of the most computationally intensive simulation in this area is the visualization of solid participating media. This media can describe many different types of object with the same physical parameters (e.g. marble, air, fire, skin, wax ...). Simulating the light interacting with it requires the computation of many independent photons interactions inside the medium. However, those interactions can be computed in parallel, using the power of modern Graphic Processor Unit, or GPU, computing. This work present an overview over different methodologies, that can affect the performance of this type of simulations on the GPU. Different existing ideas are analyzed, compared and modified with the scope of speeding up the computation respect to the classic CPU implementation. 1
154

Ověření vlivu MTCG na vytížení eNodeB v mobilní síti LTE-Advanced / Verification of MTCG's Influence on eNodeB Utilization in Mobile Network LTE-Advanced

Bartal, Boris Unknown Date (has links)
This thesis is dealing with the problem of MTC (Machine Type Communication) devices accessing LTE (Long Term Evolution) network. First part of work contains theoretical description of MTC, LTE network and possibility of using QoS (Quality of Service) for this type of communication. Influence of simultaneous access of large number of MTC devices into LTE network is examined. A solution is proposed -- usage of MTCG. In simulation enviroment NS-3 (Network Simulator 3), two scenarios are created for simulation with and without MTCG. The results of these simulations are then compared.
155

Simulace uzivatele pro statisticke dialogove systemy / User simulation for statistical dialogue systems

Michlíková, Vendula January 2015 (has links)
The purpose of this thesis is to develop and evaluate user simulators for a spoken dialogue system. Created simulators are operating on dialogue act level. We implemented a bigram simulator as a baseline system. Based on the baseline simulator, we created another bigram simulator that is trained on dialogue acts without slot values. The third implemented simulator is similar to an implemen- tation of a dialogue manager. It tracks its dialogue state and learns a dialogue strategy based on the state using supervised learning. The user simulators are implemented in Python 2.7, in ALEX framework for dialogue system development. Simulators are developed for PTICS application which operates in the domain of public transport information. Simulators are trained and evaluated using real human-machine dialogues collected with PTICS application. 1
156

Molekulární simulace interakcí nanočástic CdS s montmorillonitem / Molecular simulations of interactions among CdS nanoparticles and montmorillonite

Pšenička, Milan January 2015 (has links)
This thesis investigate the structure of cadmium sulfide (CdS) nanoparticles and its stabilization by a surfactant - cetyltrimethylamonnium cation CTA+ and further describe interactions among stabilized CdS nanoparticles and the surface of the layered clay mineral - montmorillonite with using the molecular simulation methods. Initial models of the CdS nanoparticles were build for both crystal structures (Greenockit (G) and Hawleyit (H)). The preferred orientations of the molecules of CTA+ for both crystal types of CdS nanoparticles were found with respect to minimum energy. Prefered orientation is monolayer for Greenockite and bilayer for Hawleyite. Models with the preferred orientation of the molecules of CTA+ were placed on the surface of montmorillonite and after optimization, adsorption energy of CdS nanoparticles with its envelope and montmorillonite surface was calculated. All results and used procedures were compiled in the form of practice for the subject Computational experiments in the theory of molecules I - NBCM100 taught at MFF UK in Prague.
157

Hydrodynamické a N-částicové simulace srážek asteroidů / Hydrodynamic and N-particle simulations of asteroid collisions

Ševeček, Pavel January 2016 (has links)
We study asteroidal breakups, i.e. fragmentations of targets, subsequent gravitational reaccumulation and formation of small asteroid families. We fo- cused on parent bodies with diameters Dpb = 10 km. Simulations were per- formed with a smoothed-particle hydrodynamics (SPH) code combined with an efficient N-body integrator. We assumed various projectile sizes, impact veloci- ties and angles (125 runs in total). Resulting size-frequency distributions are sig- nificantly different from results of scaled-down simulations with Dpb = 100 km targets (Durda et al. 2007). We thus derive new parametric relations describing fragment distributions, suitable for Monte-Carlo collisional models. We also characterize velocity fields and angular distributions of fragments, which can be used in N-body simulations of asteroid families. Finally, we discuss several uncertainties related to SPH simulations.
158

Využití dramatické výchovy jako metody se zaměřením na podporu zdraví na 2. stupni základní školy / Use of drama as a method with a focus on health promotion at the second stage of primary school

Lansdorf, Marek January 2017 (has links)
Thesis is focused on using drama education as a method for teaching health education during second stage of an elementary school. It specifically focuses on support of health during second stage of an elementary school. The goals of drama education and its influence on pupil's socialization are set in the thesis. Emphasis is put on role play as a basic method of drama education. The aim of the thesis is to find out if teachers of health education for second stage of an elementary school use drama methods, what topics, and their sources. Using questionnaires and interviews led to finding out that teachers use drama methods in topics that are not very sensitive for pupils. It also led to finding out that there are no handbooks focused on topics of health education by using drama methods available for teachers. A set of seven topics is a part of the thesis. It contains themes for health education with role play.
159

Využitie ekonometrických a simulačných modelov pri organizácii bežeckých pretekov / Application of econometric and simulation models in organizing a running race

Mihál, Filip January 2015 (has links)
This diploma thesis deals with application of econometric and simulation models in organizing relay running race od Tatier k Dunaju. In theoretical part the reader is introduced to basic theory regarding econometric and simulation models. Detailed introduction to od Tatier k Dunaju running race follows afterwards. There are used multiple regression models in this thesis which are used to estimate runner s time in his sector based on 10 km run reported time and track profile. Results are compared to those provided by organizer himself and between each other. Simulation models are used to analyze sufficiency of parking lots capacity, which are used by team cars while traveling between sectors. These models are compared to reality and afterwards suggestions to solve recognized issues are discussed.
160

Reálné využití metod operačního výzkumu ve spojení s logistickým principem Cross-Docking / The real use of operation research method in conjunction with logistics Cross-Docking technology

Dvořáková, Alžběta January 2016 (has links)
This diploma thesis deals with the real use of operation research method in conjunction with logistics Cross-Docking technology. It is possible to solve this conjunction with either routing problems along with its modifications or simulations methods. The theoretical part describes routing problems, routing problems with time windows, simulations methods with their possibilities of real use and logistics technologies. A model of a Cross-Docking terminal that was created in the program Simul8 can be found in the practical part of this thesis. The goal of the simulation was to ensure smooth flow of products through the terminal without any long queues in the terminal. Routing problems designed to minimize the length of its routes can be found in the second half of the practical part. Other possible real application is routing problems on the real problem. The solution for this task was found using the modelling system MPL for Windows.

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