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Significance of different financial ratios in predicting stock returns: NYSE - cross-industry analysis
Coufal, Matěj ; Mejstřík, Michal (advisor) ; Kurka, Josef (referee)
The goal of this research is to investigate the power of following seven variables to predict stock returns on the New York Stock Exchange: price to earnings ratio (P/E), dividend yield (DY), debt to equity ratio (D/E), book to market ratio (B/M), return on assets (ROA), return on equity (ROE) and market capitaliza- tion (MC). Companies selected for the analysis are divided into five industries (airlines, computers and software, financial services, food and beverages, energy) which enables to observe the difference between the sectors as far as the statistical significance of regressors is concerned. The ability of six financial ratios and MC to forecast stock returns is examined between February 2010 and February 2020, whereas three investment horizons are considered: three months, one year, three years. Panel data regression models reveal different significant variables for each industry and show that the strength of the relationship between these regressors and expected stock returns increases with a longer investment horizon.
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Significance of different financial ratios in predicting stock returns: NYSE - cross-industry analysis
Coufal, Matěj ; Mejstřík, Michal (advisor) ; Kurka, Josef (referee)
The goal of this research is to investigate the power of following seven variables to predict stock returns on the New York Stock Exchange: price to earnings ratio (P/E), dividend yield (DY), debt to equity ratio (D/E), book to market ratio (B/M), return on assets (ROA), return on equity (ROE) and market capitaliza- tion (MC). Companies selected for the analysis are divided into five industries (airlines, computers and software, financial services, food and beverages, energy) which enables to observe the difference between the sectors as far as the statistical significance of regressors is concerned. The ability of six financial ratios and MC to forecast stock returns is examined between February 2010 and February 2020, whereas three investment horizons are considered: three months, one year, three years. Panel data regression models reveal different significant variables for each industry and show that the strength of the relationship between these regressors and expected stock returns increases with a longer investment horizon.
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P and d (Practical usage of statistical and substantive significance in Czech social sciences)
Soukup, Petr ; Jeřábek, Hynek (advisor) ; Urbánek, Tomáš (referee) ; Hebák, Petr (referee)
Resume The thesis is focused on the usage of statistical and substantive significance in the Czech social science. The thesis consists of four articles (3 published, 1 unpublished yet), introduction and conclusion including practical recommendations. The aim of the thesis is theoretically describe the current " standards" in the use of statistical and substantive significance and through research (content analysis) of articles published in the three leading Czech journals (Czechoslovak Psychology , Pedagogy and Czech Sociological Journal) empirically assess whether the published articles adhere to the " standards" in the field of statistics and the substantive significance of the results . Basic research question was: How are current " standards" followed in the use of statistical and substantive significance in the Czech social science production? In addition to the basic research questions were additional (auxiliary) research questions: What are the basic limits of statistical significance, i.e. in which cases statistical tests are not appropriate to use? What are the shortcomings of statistical significance itself, and what are the most common problems in the practical use of it by researchers? What are the alternatives to the concept of statistical significance? How is it possible to assess the...
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BMI (body mass index) patient, factors influencing the radiation protection of staff in radiology
MICHEL, Tomáš
Bachelor thesis deals with personnel radiation exposure in interventional procedures in patients with different BMI. Therefore we have decided to clarify the hypothesis to what extent the impact of BMI on patient radiation exposure of personnel. The thesis is divided into 2 parts: In the theoretical part of the thesis deals with the hitherto known in the field of radiation protection in workplaces with ionizing radiation. The information obtained from the State Office for Nuclear Safety and National Radiation Protection Institute we detail the current methods of protection against ionizing radiation, radiation protection, which is based on three basic principles defined by international institutions and the legal system in all developed countries: 1. The justification of exposure 2. Optimization of protection 3. Establishment of exposure In the second part of the thesis devoted to a particular hypothesis of proof. Hypothesis is that the BMI of the patient greatly affects the radiation exposure of personnel for interventional procedures. Statistical analysis the thesis consists of two parts. The first part is a set of patients after PTA pelvic arteries and the second part is a set of patients after biliary drainage. To calculate the statistical dependence, we chose a simple linear correlation (Pearson r), resulting will be a regression line. The base set includes about 100 patients, after examining and identifying the data needed to calculate the radiation dependence, we had about half of the patients discarded for the following reasons: - We were unable to verify information in the database RO. - We were unable to verify the values for BMI. - Patients who were treated in 2006, we scrapped because they were treated to another type of angiographic device that worked in very different dose rates. - PTA in pelvic arteries undergoing different type of exercise intervention, for example: diagnosis of aortic arch, carotid arteries and examination of the lower extremities. The most serious limits of the study, however, include the use of different protective shield in each case, which brings to the measurements and calculations greatest uncertainty. It shows especially when comparing sets DZC sets and PTA, in terms of the relationship BMI and dose of physician. The DZC is used for practical reasons, only a limited, would have bothered himself transferred power. The PTA is quite the contrary, investigating may preferably between himself and the radiation field to insert shield in the form of protective Plexiglas absorbance, which is part of angiographic complete. Above all this, we explain why statistical significance BMI and dose of physician for DZC is traceable, while at the PTA it is not. From a statistical perspective, the relationship of BMI and dose impacting on patient at DZC relatively very tight at the PTA was a little less tight. This fact can be explained by the fact that the measurement data is not affected so many uncertain variables such as dose measurements in the apron. The correction of different difficulty of performance was used dividing the total fluoroscopic doses with a total time of fluoroscopy. The expression of experts on radiation protection initially resulted transferred to study with skepticism. Surprise, but was relatively strong statistical dependence in relation BMI and dose of both entities in DZC. In terms of number of patients and the homogeneity of each group is more of a pilot study. Group of patients with DZC need of the above reasons, considered more representative than the group of patients with PTA. From the findings we can confirm the existence of a correlation between the dose and the patient's constitution and staff performing interventional radiology procedures. These established facts may be relevant to the protection of personnel and should be taken into account in the design of radiological measures.
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