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Evaluation of Strain Rate Effects on Transition Behaviour Applying the Master Curve Methodology
Dlouhý, Ivo ; Kohout, J. ; Jurášek, Ladislav ; Holzmann, Miloslav
Master curve methodology has been used for an evaluation of strain rate effects on transition behaviour of wrought CrMo and cast ferritic C Mn steel.The physical aspects of strain rate effect on reference temperature has been analysed as a base for the prediction of this dependence.Statistical aspects of the strain rate effects on the master curve have been discussed showing capability of the method for the prediction of strain rate susceptibility of steel fracture behaviour. It has been experimentally proved that the master curve shape does not depend on the loading rate.The relationship between reference temperature T0 (or the shift of T0 with respect to quasi-static loading rate)and loading rate can be described with linear dependence if logarithmic scale of temporal change of stress intensity factor is considered.For experimental establishing of the dependence of reference temperature on loading rates only two T0 values as determined at different loading rates are sufficient.However,it is useful to achieve the comparable accuracy of both T0 determinations that may demand larger number of specimens for the measurement of T0 at the higher loading rate.Standard quasistatic fracture toughness has been predicted from small pre-cracked Charpy type specimens tested dynamically applying the reference temperature shift obtained experimentally.The predicted fracture toughness temperature diagram has been proved experimentally.
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Is import of goods from european countries to Czech republic more or less influenced by changes in nominal and real exchange rates than in non european countries?
Vereš, Jan ; Stroukal, Dominik (advisor) ; Slaný, Martin (referee)
This bachelor thesis analyses the connection between import of goods from foreign countries to Czech Republic and the exchange rate changes. The initial hypothesis of this paper is to prove that the depreciation of domestic currency has positive influence on balance of trade balance. For this purpose there is eight econometric models which were created by using time series from years 2003 to 2016. These models are divided in pairs among four chosen countries. For each country two models were created that follow the development of trade balance between Czech Republic and one of the countries in two different time frames. All the models always use the real effective exchange rate, growth rate of GDP for Czech Republic and growth rate of GDP for one of the countries as explanatory variable. It is connected with the second task of this thesis, which is the analysis of the differences in the behaviour of the models that belong to the countries which are members of the EU and these that are not. The aim is to find out whether the existence of tariffs on imported goods from countries out of the EU causes visible differences in the behaviour of the variables that were included in the models. Based on the outcomes of all eight models the main hypothesis has been proved right for three out of four countries. In the models for Germany, China and France the relation of real exchange rate and trade balance came out as positive in long term, in short term the outcome was ambiguous. The second question of this thesis has been answered, but its added value is questionable. The final models for each state do show some noticeable differences and they can be used to determine if the influence of the change of exchange rates on trade balance is smaller or bigger in the countries where tariffs are used. On the other hand, from the results we can learn that the sample of only four countries is insufficient for the deduction of any conclusions.
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The Controlling Study
Herda, Tomáš ; Mikovcová, Hana (advisor) ; Herda, Zdeněk (referee)
The main goal of this Diploma´s Thesis is to make a model for calculation of water and sewer rates for the company Vodovody a kanalizace Náchod, a.s. when sticking to the set criteria both from the side of VaK Náchod, a.s. and law regulations. Based on the theoretical part an analysis of customer sensitivity to the price changes using the data for last 20 years follows. Findings from the first two parts are used in risk analysis in next part. The created model calculates the water and sewer rates based on the information from the company accounting system in the way to generate sufficient financial resources to fulfill the renovation plan of infrastructural property plant and equipment and to transfer given amount to the company funds. In addition, the model monitors whether the legal condition of maximal allowable increase of profit per m3 is met. In the customer sensitivity to the price changes part the price elasticity of demand for water and sewer rates is calculated based on the data from 1995 to 2015. The assumption of inelastic demand is confirmed. Risk analysis part is deals with potential risk regarding the demand and prices. Potential impacts for the most significant risk are quantified. The analysis uses knowledge gained in the first two parts. It was confirmed that potential risks are exiting but do not have any significant impact on the going concern of VaK Náchod, a.s. The created model has been already used for the calculation of prices for the year 2017. Customer sensitivity analysis to the price changes and link to the potential risks is an additional information for VaK Náchod, a.s. which validates that nowadays, there are no significant threats which could affect the demand and water and sewer rates significantly.
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Use of Interest Rate Models for Interest Rate Risk Management in the Czech Financial Market Environment
Cíchová Králová, Dana ; Arlt, Josef (advisor) ; Cipra, Tomáš (referee) ; Witzany, Jiří (referee)
The main goal of this thesis is to suggest an appropriate approach to interest rate risk modeling in the Czech financial market environment in various situations. Three distinct periods are analyzed. These periods, which are the period before the global financial crisis, period during the financial crisis and in the aftermath of the global financial crisis and calming subsequent debt crisis in the eurozone, are characterized by different evaluation of liquidity and credit risk, different relationship between financial variables and market participants and different degree of market regulations. Within this goal, an application of the BGM model in the Czech financial market environment is crucial. Use of the BGM model for the purpose of predicting a dynamics of a yield curve is not very common. This is firstly due to the fact that primary use of this model is a valuation of interest rate derivatives while ensuring the absence of arbitrage and secondly its application is relatively difficult. Nevertheless, I apply the BGM model to obtain predictions of the probability distributions of interest rates in the Czech and eurozone market environment, because its complexity, direct modeling of a yield curve based on market rates and especially a possibility of parameter estimation based on current swaptions volatilities quotations may lead to a significant improvement of predictions. This improvement was also confirmed in this thesis. Use of swaptions volatilities market quotations is especially useful in the period of unprecedented mone- tary easing and increased number of central banks and other regulators interventions into financial markets that occur after the financial crisis, because it reflects current market expectations which also include future interventions. As a consequence of underdevelopment of the Czech financial market there are no market quotations of Czech koruna denominated swaptions volatilities. I suggest their approximations based on quotations of euro denominated swaptions volatilities and also using volatilities of koruna and euro forward rates. Use of this approach ensures that predictions of the Czech yield curve dynamics contain current market expectations. To my knowledge, any other author has not presented similar application of the BGM model in the Czech financial market environment. In this thesis I further predict a Czech and Euro area money market yield curve dynamics using the CIR and the GP models as representatives of various types of interest rates models to compare these predictions with BGM predictions. I suggest a comprehensive system of three criteria, based on comparison of predicti- ons with reality, to describe a predictive power of selected models and an appropria- teness of their use in the Czech market environment during different situations in the market. This analysis shows that predictions of the Czech money market yield curve dynamics based on the BGM model demonstrate high predictive power and the best 8 quality in comparison with other models. GP model also produces relatively good qua- lity predictions. Conversely, predictions based on the CIR model as a representative of short rate model family completely failed when describing reality. In a situation when the economy allows negative rates and there is simultaneously a significant likelihood of their implementation, I recommend to obtain predictions of Czech money market yield curve dynamics using GP model which allows existence of negative interest rates. This analysis also contains a statistical test for validating the predictive power of each model and information on other tests. Berkowitz test rejects a hypothesis of accurate predictions for each model. However, this fact is common in real data testing even when using relatively good model. This fact is especially caused by difficult fulfilment of test conditions in real world. To my knowledge, such an analysis of the predictive power of selected interest rate models moreover in the Czech financial market environment has not been published yet. The last goal of this thesis is to suggest an appropriate approach to obtaining pre- dictions of Czech government bonds risk premium dynamics. I define this risk premium as a difference between government bond yields and fixed rate of CZK IRS with the same length. I apply the GP model to describe the dynamics of this indicator of the Czech Republic credit risk. In order to obtain a time series of the risk premium which are necessary for estimation of GP model parameters I firstly estimate yield curves of Czech government bonds using Svensson model for each trading day since 2005. Resulting si- mulations of risk premium show that the GP model predicts the real development of risk premiums of all maturities relatively well. Hence, the proposed approach is suitable for modeling of Czech Republic credit risk based on the use of information extracted from financial markets. I have not registered proposed approach to risk premium modeling moreover in the Czech financial market environment in other publications.
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Differences between men and women in the Czech labour market
Stroukal, Dominik ; Kadeřábková, Božena (advisor) ; Pavelka, Tomáš (referee) ; Němec, Otakar (referee)
This thesis consists of five articles that apply current world research on labor economics at the Czech Republic and confirms the significant differences between men and women in this market. It shows that gender has a significant influence on the preference on the labor market and, consequently, on employment and health. First, the thesis shows that preferences are relevant determinant of career and then we study the difference in preference of salary for men and women. Subsequently it shows that gender plays a significant role in explaining the relationship between homeownership, and unemployment, as well as unemployment and health. The first chapter was able to demonstrate that the preference for a career has a positive influence on the choice of career. The influence of higher education on prioritizing career proved to be positive and significant. Probability of a career choice is reduced by the presence of children, however, is not dependent on their number, which is contrary to the theory of preferences. The second chapter shows that Czech women prefer more non-monetary rewards than men. It has also been shown that people with university education are same in the preferences of non-monetary rewards regardless of the gender of the respondents, however, compared to the world's research, the Czech higher education increases this preference. It turned out that women prefer risk less than men. The third chapter demonstrates that although the housing market undermines labor mobility and employment in the Czech Republic at the regional level, therefore, that in regions with a higher rate of home ownership is higher unemployment, at the individual level, the owners of housing are unemployed are less likely. The estimates are significantly different for men and women. Men living in owner-occupied housing have a higher likelihood of employment than women. At regional level, however, this thesis shows that the high rate of home ownership increases unemployment for both men and women, in the long run only to women. The fourth chapter showed that men transition to homeownership reduces the likelihood of unemployment next year. For women, this relationship has proved to be insignificant. In addition, as insignificant showed the opposite relationship, the transition from unemployment to the newly acquired home ownership. The last chapter shows that the change in the working status to unemployment will increase in the future probability of worse health. Influence in less than two years, however, proved to be significant. An important conclusion is that men have a significantly stronger relationship between health and unemployment than women.
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Global Economy Outlook - November 2016
Česká národní banka
The November issue of Global Economic Outlook presents the regular monthly overview of recent and expected developments in selected territories, focusing on key economic variables: inflation, GDP growth, leading indicators, interest rates, exchange rates and commodity prices. In this issue, we also focus on the relationship between the Brent crude oil price and the US dollar exchange rate over the last ten years. The results show that the inverse relationship between the Brent price and the nominal effective exchange rate of the dollar still applies, helping dampen fluctuations in the dollar price of oil in “non-dollar” economies.
Fulltext:  PDF; PDF
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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.
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The use of biomass ash
Ochecová, Pavla ; Tlustoš, Pavel (advisor) ; Radim, Radim (referee)
One of the most frequently used sources of renewable energy is biomass, mainly wood biomass. Incineration is the most common technology utilizing the energy from biomass to produce heat. A byproduct of these technologies is ash, whose composition depends on the feedstock composition and the incineration technologies. Due to the high content of valuable nutrients in ash, one of the suitable option for ash utilization seems to be application into agricultural or forestry land. Therefore, it is necessary to test response of soils and plants and look for the most suitable combination of soil additive (biomass ash), and plants. Experimental part of PhD thesis was divided into the incubation experiment and the vegetation pot experiments. The incubation experiment: The efficiency of ash addition at two application rates was tested for nutrients enrichment in different soils within period of 56 days. The vegetation pot experiments: The two plants Triticum aestivum L: (three-year experiment) and Lolium perenne L. (one-year experiment) were planted in the 5L pots. Soils were treated with ash or ash combinated by superphoshate and flue gas desulfurization gypsum. For both plants, we evaluated the plant growth, biomass production and content of macro, micro and toxic elements in the biomass and in the soils.
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Confidence Cycles and Liquidity Hoarding
Audzei, Volha
Market confidence has proved to be an important factor during past crises. However, many existing general equilibrium models do not account for agents’ expectations, market volatility, or overly pessimistic investor forecasts. In this paper, we incorporate a model of the interbank market into a DSGE model, with the interbank market rate and the volume of lending depending on market confidence and the perception of counterparty risk. In our model, a credit crunch occurs if the perception of counterparty risk increases. Our results suggest that changes in market confidence can generate credit crunches and contribute to the depth of recessions. We then conduct an exercise to mimic some central bank policies: targeted and untargeted liquidity provision, and reduction of the policy rate. Our results indicate that policy actions have a limited effect on the supply of credit if they fail to influence agents’ expectations. Interestingly, a policy of a low policy rate worsens recessions due to its negative impact on banks’ revenues. Liquidity provision stimulates credit slightly, but its efficiency is undermined by liquidity hoarding.
Fulltext: PDF
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Partial Report IV / 2016 - Rating of the deformation stress monitoring the state of the rock mass during mining coal seam 30 (634) within the trial operation of mining method corridor - a pillar in OPJ ČSM - NORTH
Waclawik, Petr ; Ptáček, Jiří ; Kukutsch, Radovan ; Kajzar, Vlastimil ; Koníček, Petr ; Souček, Kamil ; Staš, Lubomír
Monitoring of the deformation stress state of the rock mass is a prerequisite for the verification of unapproved new mining methods hall-pillar and its further application in the Czech part of the Upper Silesian coal basin. This mining method is designed on the basis of experiences and practices that are verified in different natural conditions and depths below the surface and is therefore essential for the verification of conditions for the Czech part of the Upper Silesian Basin based on geotechnical monitoring. The present report is prepared on the basis of a contract no. 942/50/10, where the Institute of Geonics, v.v agrees to make periodic evaluation of monitoring data napěťodeformačního state of the rock mass. In accordance with the aforementioned agreement, the message is processed in the six-month period and continues in the interim report III / 2015 (Waclawik et al. 2015) passed buyers in April this year. Interim results of the geotechnical monitoring, such as the experience gained during the first conquest dobývky V show specifics of natural conditions in trial operation unapproved new mining methods hall-pillar.
Fulltext: content.csg - PDF
Plný tet: UGN_0464907 - PDF
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