National Repository of Grey Literature 18,843 records found  1 - 10nextend  jump to record: Search took 0.52 seconds. 

Dynamic analysis of the human supraglottal space considering acoustic-structural interaction
Dedouch, K. ; Horáček, Jaromír ; Veselý, Jan ; Vampola, T. ; Svec, J. G.
A simplified finite element) model of the human vocal tract is presented and its fundamental vibroacoustic characteristics are analysed. Solid-fluid interaction and acoustic wall impedance are taken into account on some parts of the boundaries of the acoustic space.

A Comparison of Two Models of the Energy Market Development in Czech Republic from 2015 to 2040
Dvořáková, Jitka ; Zeman, Martin (advisor) ; Lukášová, Tereza (referee)
The bachelor thesis is focused on the prediction of the energy market in the Czech Republic between 2015 and 2040 and on the comparison of potential costs related to two models of energy portfolio management. The first model was created according to the National Energy Concept from 2014, while the other one was designed artificially to simulate usage of the renewable resources in 50% of the electric energy production. The theoretical part of the thesis discusses the recent situation of the Czech energy market, defines types of energy resources and explains terms related to the discussed topic. In the practical part, direct production costs of different kinds of power plants were computed and used to estimate economic demands of the two considered models. The efficiency of both models was compared and evaluated. The aim of the thesis was to decide, which of the two models would be more favourable for the Czech national economy. Key words: energy, energy market, direct costs, economic advantage JEL classification: Q40, Q41, Q43, Q47

Technological Foresight: Analysis of Potentially Disruptive Future Technologies in Banking
Dunovský, Tomáš ; Jiřinová, Kateřina (advisor) ; Žďára, Tomáš (referee)
This Master's Thesis is focused on technological foresight in the banking industry in Europe. It includes consecutive two parts. The first one is theoretical and focuses on defining the terms necessary for the development of technological foresight, stated criteria, triggers and terms necessary for the development of analysis of potential technological problems and their solutions. The second part is practical and it includes the technological foresight, analysis of trends that will disrupt banking and introduce a vision of personal banking product of the future. A comparison of product vision to current trends and if those can be considered disruptive follow this part. The last part of the thesis includes diffusion criteria of innovation as according to the Rogers's Model, a set of triggers after which the defined investment fund can consider an investment into technology, and an analysis of potential technological issues with proposed solutions.

Multicriteria games
Tichá, Michaela ; Dlouhý, Martin (advisor) ; Lachout, Petr (referee) ; Čičková, Zuzana (referee)
Theory of multicriteria games is a special field of game theory, when one or more players have at least two payoff functions and want to maximize simultaneously. The work introduces a number of new findings. It examined the concept of finding equilibria in pure strategies in noncooperative multicriteria game. It is possible to find all the equilibria in pure strategies by full search and solving two linear programs for each point. Furthermore, two linear programs are formulated for verifying that a selected point is the equilibrium of the game or not. In the noncooperative games is also introduced the concept that with knowledge of the equilibrium of bimatrix game determines preferences of the players. Although finding the equilibrium point of the bimatrix game is nonlinear problem, finding the preferences is linear problem. The latest findings in the noncooperative games is a generalization of the concept that solves multicriteria game by assigning weights to each criterion of each player. The work demonstrates that it may not be necessarily linear weights, but it can be more general function that describes the player's preference. The remaining part is devoted to knowledge in cooperative games. There is considered that the players know their preferences and are able to express them by weights. The game with known preferences is defined and solved with the use of bargaining theory. Then it is generalized to a case where players have more payoff functions, from which they can choose. Finally, the multicriteria case of voting game is defined. It is designed completely new concept, which selects the winning coalition in the voting game. This concept is then applied to the real situation after the elections to the Chamber of Deputies in 2013.

Multimedia communication
Vondra, Zdeněk ; Horný, Stanislav (advisor) ; Skrbek, Jan (referee) ; Jurášková, Olga (referee)
Multimedia is a form of communication and sharing knowledge using synergic effect of parallel connected communication channels. Its main use is in producing communications products and services and in design of user interfaces. Main objective of this dissertation is to develop and create a model of multimedia communication for better understanding of the meaning and the purpose of using multimedia forms in communication process. The model will describe a system of elements and parameters of multimedia communication within the internal and external context. Another objective of this dissertation is to develop multimedia communication methodology that will be used for the design, development and evaluations of concepts of multimedia communication. The methodology will be created by applying the model of multimedia communication into the procedure structure. In theoretical way this dissertation is based on analysis of different definitions and approaches to the multimedia communications topic. This is followed by an analysis of communication theories, concepts of media, multimedia, delivery channels, and communication functions. The theoretical part is followed by the outcomes of the research in practice of four different fields of multimedia use. The knowledge gained is analyzed in the following parts in purpose of creating the model of multimedia communication and the methodology which is derived from the model. The methodology is further validated through case studies and the recommendations for further development are formulated. The model and the methodology of multimedia communication created in this dissertation present complex view on multimedia communication topic that is considered as a useful tool for meeting a specific communication purpose. Dissertation provides mechanics for use and study of multimedia communication and also defines the opportunities for further development of the methodology.

NUMERICAL ESTIMATION OF MICRO-CRACK PATHS IN POLYMER PARTICULATE COMPOSITE
Majer, Z. ; Náhlík, Luboš
Determination of composite mechanical behavior is one of important part during the composite tailoring. The aim of the present work was to estimate a micro-crack behavior in a polymer particulate composite. The composite was investigated by means of the finite element method -using ANSYS software. A two-dimensional three-phase finite element model was developed to analyze the crack growth behavior. The assumptions of the linear elastic fracture mechanics were considered and the Maximum Tangential Stress (MTS) criterion was used to predict the direction of the crack propagation. The effect of the elastic modulus of the interphase on the micro-crack propagation was investigated. The properties of matrix and particles were taken from experiment. It was shown that the interphase properties influence the stress intensity factor KI as well as the micro-crack paths. The results of this paper can contribute to a better understanding of the micro-crack propagation in particulate composites with respect to the interphase.

Effect of snowpack on runoff generation during rain on snow event.
Juras, Roman ; Máca, Petr (advisor) ; Ladislav , Ladislav (referee)
During a winter season, when snow covers the watershed, the frequency of rain-on-snow (ROS) events is still raising. ROS can cause severe natural hazards like floods or wet avalanches. Prediction of ROS effects is linked to better understanding of snowpack runoff dynamics and its composition. Deploying rainfall simulation together with hydrological tracers was tested as a convenient tool for this purpose. Overall 18 sprinkling experiments were conducted on snow featuring different initial conditions in mountainous regions over middle and western Europe. Dye tracer brilliant blue (FCF) was used for flow regime determination, because it enables to visualise preferential paths and layers interface. Snowpack runoff composition was assessed by hydrograph separation method, which provided appropriate results with acceptable uncertainty. It was not possible to use concurrently these two techniques because of technical reasons, however it would extend our gained knowledge. Snowmelt water amount in the snowpack runoff was estimated by energy balance (EB) equation, which is very efficient but quality inputs demanding. This was also the reason, why EB was deployed within only single experiment. Timing of snowpack runoff onset decrease mainly with the rain intensity. Initial snowpack properties like bulk density or wetness are less important for time of runoff generation compared to the rain intensity. On the other het when same rain intensity was applied, non-ripe snowpack featuring less bulk density created runoff faster than the ripe snowpack featuring higher bulk density. Snowpack runoff magnitude mainly depends on the snowpack initial saturation. Ripe snowpack with higher saturation enabled to generate higher cumulative runoff where contributed by max 50 %. In contrary, rainwater travelled through the non-ripe snowpack relatively fast and contributed runoff by approx. 80 %. Runoff prediction was tested by deploying Richards equation included in SNOWPACK model. The model was modified using a dual-domain approach to better simulate snowpack runoff under preferential flow conditions. Presented approach demonstrated an improvement in all simulated aspects compared to the more traditional method when only matrix flow is considered.

Arctic tundra dendrochronology
Lehejček, Jiří ; Svoboda, Miroslav (advisor) ; Monika, Monika (referee)
Historically unprecedented environmental change in the Arctic ecosystems is often given into the context of its past and possible future development. In the region where instrumental meteorological observations are scarce archives need to be investigated in order to address this issues. The comprehensive synthesis one of the archives: long-live circumpolar evergreen Juniperus communis L. shrub is presented here. 20 individuals from southwest Greenland were investigated at the cell anatomy level to understand the ecology of the species and unhide its potential for environmental and climate reconstructions. The findings are as follows: i) Stop of exponential cross-sectional conduit-lumen widening with increasing age is in contrast with conduit-lumen nature of trees. This indicates that shrubs do not need to saturate their water and nutrient demands via traits of classical hydraulic conductivity law but rather developed different mechanisms. Extreme weather conditions result in prostrate growth form. However, different weather factors probably influence shrub growth differently: While snow and wind act mechanically (a), temperature influences the form of growth physiologically (b). a) So long as the young shrub stem has high resilience to bend back to an upright position after snow melt and so long as it can withstand the wind during the vegetation season it most likely grows upright and the conduit-lumens widen. b) Temperature, resp. freeze-thaw events are responsible for the shrubs preference of safety (finite size of conduit-lumens) over hydraulic efficiency, thus not allowing for more primary growth. All of these (and other) factors are apparently working together and the transition of vertical to more horizontal growth is gradual. As a consequence, the conduit-lumen sizes may not have to be further increased (due to ecophysiological restrictions possibly also must not) because water is no longer transported against gravity. ii) Observed age/growth trend has to be taken into consideration for further employment of the wood anatomical parameter in paleoenvironmental studies. That is, shrub cell parameters can only be used for this purposes if correctly detrended. This allows for more accurate as well as longer reconstructions because youth trend was often neglected in reconstructions based on shrub annual-rings. iii) The south-western Greenland Ice-Sheet (GrIS) melt rates reconstruction is presented for the whole 20th century. This part of GrIS is considered as the most active. According to the presented reconstruction current GrIS melt rates are not uncommon for the last century being comparable to first decades of 20th century. This finding is particularly important contribution to the debate on Atlantic meridional overturning circulation (AMOC). Too high fresh water inputs into the Northern Atlantic from GrIS melting may slow down or even stop the AMOC which would result in more continental climate in Europe. Presented results indicate that this threshold lies higher than observed current melt rates of GrIS. Fascinating Juniperus comunnis species has shown to be able to address many ecological as well as environmental open questions and due to its longevity and abundant distribution has a great potential to become an important player in the Arctic research.

Nutritional analysis and optimization of breeding of selected species of edible insects under conditions of the Czech Republic with regard to human health
Adámková, Anna ; Kouřimská, Lenka (advisor)
All over the world, the edible insects are considered a highly nutritious food with high protein and fat content. However, the nutritional value of insect is not constant. It can be affected by species, developmental stage, rearing technology or nutrition. Therefore, this thesis was aimed at obtaining the selected nutritional value of edible insects. Analyses were focused on the determination of the crude protein content, fat content, fatty acid profile and sterols in selected species of edible insects, which can be commonly reared in the Czech Republic. At the same time we also analysed samples of insects reared on the island of Sumatra to evaluate the influence of the climate on the nutritional value. The main aim of the thesis was the determination of optimal breeding conditions, developmental stages and feed rations for obtaining good production of insects with nutritional properties suitable for human nutrition. The analyses showed a high nutritional value of selected insect species, but also confirmed the significant differences in the content of individual nutrients between different species depending on the climate conditions and developmental stage. Comparing the fat and crude protein content in edible insects and other conventional sources of meat it has been found, that the examined insect is similar to beef concerning the fat and crude protein content. The results obtained are the basis for determining the appropriate rearing conditions and developmental stages for obtaining insect with the desired nutritional properties for human nutrition.

Influence of meadow management on the migration behavior of selected species of butterflies
Bubová, Terezie ; Langrová, Iva (advisor) ; Farkač, Jan (referee)
Migrations are the key process and one of the basic biological features, which allow survival of endangered species in fragmented landscape. In the last decades, agriculture intensification, industry and urbanization caused that number of natural butterfly habitats has significantly decreased. The localities originally suitable for butterflies are currnetly converted to farmland or building plots. This PhD thesis aimed to find a compromise solution of meadow management, which should allow a commercial use and concurrently do not jeopardize the continued existence of endangered or threatened species. The main idea of this study was in the intentional emigration causing in the middle of flight period, which should lead into resettlement of the population to another (potentially more suitable) locality. Possibility of aimed manipulation with butterfly emigrations would be considered as a major breakthrough in their protection. The investigated species Phengaris nausithous (Bergsträsser, 1779) and Phengaris teleius (Bergsträsser, 1779) are both considered to be flagship species for protection of European butterflies at open meadows. This study is based on research, which was carried out in 2013-2015 at 17 patch in localities Dolní Labe, Czech Republic. In above mentioned years, one selected meadow was mowed in the middle of flight season and the emigrations were then monitored using mark-release-recapture method. Results of population and migration characteristics were calculated in MARK 8.1 software. Subsequently, the effect of mowing on emigration (comparison of emigrations from the meadow before and after mowing) was evaluated using Statistica 13. The hypotheses of this study were based on the assumption, that the loss of resources after well-timed mowing should increase the activity of adult butterflies. During the monitoring, number of emigrations was increased only in flight season 2015. Unfortunately, the statistical evaluation did not show significant effect of mowing on migrations. On the other hand, the hypothesis dealing with colonization of nearest meadows was confirmed. Effect of intentional emigration caused by management interventions was unfortunately not proved. However, we found out, that even though the population at one mowed meadow decreased clearly, the metapopulation size at the locality remained more or less stable. At investigated (mowed) meadow, there was observed a sharp decline of P. nausithous abundance. On the other hand, P. teleius population was only slightly reduced. It is therefore conceivable, that P. teleius are not as susceptible to innapropriate term of mowing. The results obtained in our research conclusively displayed no possible positive effect of mowing in the middle of flight season and a necessity of suitable management maintenance at localities inhabited by Phengaris butterflies.