|
|
Exercise-based predictors of atrial fibrillation recurrence in patients undergoing catheter ablation.
Mátych, Martin ; Pešl, Martin (referee) ; Hejč, Jakub (advisor)
Atrial fibrillation (AF) is the most frequently treated heart arrhythmia. Radiofrequency catheter ablation is a treatment option with a success rate ranging from 60 % to 80 % for paroxysmal AF. This work aimed to determine parameters associated with AF recurrence to identify high-risk patients. Data from 98 patients who underwent pulmonary vein isolation were analyzed. Out of these patients, 19 experienced AF recurrence. Exercise and echocardiographic parameters differed significantly between the recurrence and non-recurrence groups and were used in regression analysis. Peak oxygen consumption (pVO2) was found to be a strong predictor of AF recurrence after adjusting for gender and age (hazard ratio 0.43). Four parameters were identified as the ideal combination in multivariable analysis: pVO2, septal peak late diastolic mitral annulus velocity, post-exercise systolic blood pressure, and left atrial volume index. These findings highlight the importance of stress and echocardiographic parameters in predicting the success of ablation procedures.
|
|
|
Regression study of economic indicators and political stability
ŽIŠKA, František
This thesis explores relationships among many different economic indicators and a change of leading party in a government. These relationships or influences maybe small and insignificant, or they can be statistically significant. Firstly, theoretical part explains how economics influence politics and vice versa. Secondly, theoretical part includes all economic indicators used in the analytical part of this thesis with some basic explanations of the indicators and some examples of a development of the said indicators. Next part of the thesis is methodology, where the collection of data is thoroughly explained, and all the analytical tools and practices are described there too. The last part, the practical part, focuses on using the tools mentioned in methodology to find a statistically significant relationship between the economic indicator and the change of presidency and resulting in a statement, which indicators influence elections the most. Apart from that, there is a code in Python which was used to create all the analysis in this paper.
|
|
|
Analysis of impact of noise in recordings on the automated detection of hypokinetic dysarthria
Havelková, Nikola ; Galáž, Zoltán (referee) ; Kováč, Daniel (advisor)
This thesis deals with the automated detection of hypokinetic dysarthria by analysing the influence of noise present in recordings. Appropriate single-channel methods, specifically the spectral subtraction and Kalman filter, are selected and implemented in the MATLAB R2022a to enhance speech. These methods are also used for noise-free recordings, to which additive white noise was added. Afterwards, the effectiveness of these methods is objectively evaluated by using signal-to-noise ratio values. After enhancing of speech, interferences are extracted from the recordings. The effect of the presence of noise, as well as its subsequent suppression by individual methods, is then evaluated by statistical analysis, specifically using the Kruskal-Wallis test and the post hoc Dunn’s test. The probability of distributing parameters of clean, noisy and enhanced recordings, for which the effect of noise is significant, according to statistical tests, are plotted using violin and box graphs. Finally, the classification was done by logistic regression with the help of machine learning, where the effect of the presence of noise and subsequent speech enhancement on automated detection of hypokinetic dysarthria was described according to the area values under the ROC curve.
|
|
|
Lapse Analysis of Insurance Contracts
Strnad, Jan ; Mertl, Jakub (advisor) ; Mazurová, Lucie (referee)
The aim of the present work is to develop a tool for identification of Motor Third Party Liability insurance contracts which are at risk of cancellation. Methods for explorative data analysis, building a logistic regression model, comparing models and their validation and calibration are presented. Several models are developed on the real dataset using mentioned methods and then the final one is chosen. Behavior of the final model is verified by the validation on the out-of-time sample. Last step is calibration of the model to the expected value of the future portfolio cancellation rate.
|
|
|
Being an Older Mother: Metamorphoses of Late Motherhood from the Foundation of Czechoslovakia up to the Present
Šimečková, Michaela ; Fialová, Ludmila (advisor) ; Kocourková, Jiřina (referee) ; Hašková, Hana (referee)
Being an Older Mother: Metamorphoses of Late Motherhood from the Foundation of Czechoslovakia up to the Present Abstract The doctoral thesis gives a macro-structural view of the metamorphoses of late motherhood, here defined as motherhood of women aged over 35, as they have occurred in the Czech lands between 1920 and 2015. The study examines to which extent the reflection of late motherhood in selected professional and feminine / lifestyle periodicals converges with the findings derived from demographic data analysis. For this purpose, a mixed methods research has been conducted to link the conclusions from quantitative analysis of demographic data (demographic analysis and binary logistic regression) to those from qualitative and quantitative media analyses (discourse and content analyses). As the study shows, the development of late motherhood in the Czech lands varies across a range of possible perceptions in the media, levels and fertility rates. The thesis shows a strong coherence between the perception of late motherhood in the media and conclusions drawn from the demographic data analysis, which are consistent for most of the observed years. According to the results of the analysis, with some simplification, five different types of late motherhood are determined. The first type, the "Experienced...
|
|
|
Regression goodness-of-fit criteria according to dependent variable type
Šimsa, Filip ; Hanzák, Tomáš (advisor) ; Hlubinka, Daniel (referee)
This work is devoted to the description of linear, logistic, ordinal and multinominal regression models and interpretation of its parameters. Then it introduces a variety of quality indicators of mathematical models and the re- lations between them. It focuses mainly on the Gini coefficient and the coefficient of determination R2 . The first mentioned is established by modifying the Lorenz curve for ordinal and continuous variables and by comparing the estimated proba- bilities for nominal variable. The coefficient of determination R2 is newly defined for the nominal variable and is examined its relationship with Gini coefficient. As- suming normally distributed scores and errors of the model is numerically derived the relation between the Gini coefficient and the coefficient of determiantion for different distribution of continuous dependent variable. Theoretical calculations and definitions are illustrated on two real data sets. 1
|
|
|
Application of (geo)demographic methods in education
Šebestík, Libor ; Hulíková Tesárková, Klára (advisor) ; Fialová, Ludmila (referee)
Application of (geo)demographic methods in education Abstract This master's thesis presents the possibilities of application of demographic, geodemographic and statistical methods on data published by the educational sector. The methods of demographic analysis are represented by the usage of rates, the concept of multistate demography (Markov chains) and the application of life tables. The enrollment ratio at particular levels of education, the average length of schooling and the number of dropouts from school grades are evaluated by these procedures. Markov chains which are based on the probabilities of transition between grades are also examined in terms of their use for forecasting purposes. These methods analyze the situation at the preschool, primary and secondary levels and are used on data from the annual Statistical Yearbooks on Education. In the field of geodemography, the so called preferential model of migration flows is presented. This model examines how applicants for tertiary education prefer or reject the regions of the Czech Republic for their tertiary education studies. The last method is the binary logistic regression which analyzes the inequalities in access to tertiary education. Both preferential model and logistic regression are based on data files on the admission process at...
|
|
|
Fertility postponement in the Czech Republic and selected European countries in the period 1990−2015
Tovarová, Lenka ; Kurtinová, Olga (advisor) ; Šťastná, Anna (referee)
Fertility postponement in the Czech republic and selected European countries in the period 1990−2015 Abstract We have been able to observe the trend of shifting of maternity to later periods of life in European countries since the second half of the 20th century. However crucial for this thesis is to determine whether there have been disparity in delaying of maternity between selected Eastern European (Czech Republic, Slovakia, Poland) and Western European (Germany and Austria) countries since 1990 till present. The goal of this work is to find the relationship among setting of family policies, fertility rate of older women and respondents' views. In the first part of this thesis are outlined basic theories explaining postponing of maternity. There are also listed consequences related to the late maternity. The thesis touches a topic of family policies which influence the phenomenon of late maternity. It presents several fundamental tools of family policies and compares them among selected countries. The second part focuses on a description of demographic indicators that demonstrate the shift in timing of maternity. The main analysis in this thesis is a logistic regression, which explains respondent's views on issues related to a harmonization of family and employment by selected explanatory variables from...
|
|
|
Late matherhood from demographic point of view (example of The Czech and Slovak Republic)
Vobořilová, Michaela ; Fialová, Ludmila (advisor) ; Bartoňová, Dagmar (referee)
Late Motherhood from Demographic Point of View (Example of the Czech and Slovak Republic) Abstract The thesis thematically refers the issue of late motherhood in the Czech and Slovak Republics from the twenties of the twentieth century to the present from a demographic point of view. It describes the changes that have occurred during the observed years as to fertility of women aged over 35, using selected demographic indicators. In the second part the focus lies on the analysis of selected demographic factors using binary logistic regression. In the very end, the form of late motherhood is discussed. According to the results of the analysis are determined three different types of late motherhood. Keywords: late motherhood, late maternity, fertility, Czech Republic, Slovak Republic, logistic regression
|
|
|
Comparison of logistic regression and decision trees
Raadová, Zuzana ; Voříšek, Jan (advisor) ; Komárek, Arnošt (referee)
In this thesis we describe a classification of the binary data. For discussing this problem we use two well-known methods - logistic regression and decision trees. These methods deal with the problem in different way, so our aim is to compare a successfulness of their predictions. At first a model of logistic regression is introduced and we show how to estimate its parameters using a method of maximum likelihood. Then we describe decision trees as one of the most popular classification tools. There are discussed older classic algorithms CART and C4.5 and also two new algorithms GUEST and CRUISE. The predictions of both of the methods are shown on a real data example.
|
guest ::
