Attention deficit/hyperactivity disorder (ADHD) is associated with complex neurocardiac integrity. We aimed to study heart rate time asymmetry as a nonlinear qualitative feature of heart rate variability indicating complexity of cardiac autonomic control at rest and in response to physiological stress (orthostasis) in children suffering from ADHD. Twenty boys with ADHD and 20 healthy age-matched boys at the age of 8 to 12 years were examined. The continuous ECG was recorded in a supine position and during postural change from lying to standing (orthostasis). Time irreversibility indices - Porta’s (P%), Guzik’s (G%) and Ehlers’ (E) - were evaluated. Our analysis showed significantly reduced heart rate asymmetry indices at rest (P%: 49.8 % vs. 52.2 %; G%: 50.2 % vs. 53.2 %; p<0.02), and in response to orthostatic load (P%: 52.4 % vs. 54.5 %, G%: 52.3 % vs. 54.5 %; p<0.05) associated with tachycardia in ADHD children compared to controls. Concluding, our study firstly revealed the altered heart rate asymmetry pattern in children suffering from ADHD at rest as well as in response to posture change from lying to standing (orthostasis). These findings might reflect an abnormal complex cardiac regulatory system as a potential mechanism leading to later cardiac adverse outcomes in ADHD., I. Tonhajzerová, I. Ondrejka, I. Farský, Z. Višňovcová, M. Mešťaník, M. Javorka, A. Jurko Jr., A. Čalkovská., and Obsahuje bibliografii
In this paper, an angular tracking control based on adaptive super twisting algorithm (ASTA) for a Twin Rotor System is presented. With the aim of implementing the ASTA control and taking into consideration the difficulties of measuring some of its states, a Nonlinear Extended State Observer (NESO) is employed to estimate the vector state and furthermore unmeasured dynamics. This scheme increases robustness against unmodeled dynamics and external disturbance, reducing modeling difficulties due to the fact that it is not necessary to know all the parameters of the system. Furthermore, an analysis of stability is provided, where sufficient conditions are given in order to guarantee the stability of the closed-loop system. Experimental results demonstrate the feasibility of the control scheme and illustrate its performance under external disturbance. and Na konci mezi autory uvedena podoba s diakritikou Jesús DeLeón-Morales
V tomto příspěvku shrneme současný vývoj v oblasti generace ultrakrátkých pulzů volných elektronů urychlených na vysoké energie, které budou v budoucnu sloužit ke studiu a zobrazování dynamiky elektronických excitací v pevných látkách a nanostrukturách. Za tímto účelem byly vyvinuty dvě optické metody využívající koherentní interakce mezi optickým polem a elektrony ve vakuu., In this contribution we review the recent progress in the field of ultrashort high-energy electron pulse generation for applications in time-resolved imaging of electronic dynamics in bulk solids and nanostructures. For this purpose, two novel experimental techniques have been developed based on the coherent interaction between optical fields and electrons in vacuum., Martin Kozák., and Obsahuje bibliografické odkazy
One focus of data analysis in formal concept analysis is attribute-significance measure, and another is attribute reduction. From the perspective of information granules, we propose information entropy in formal contexts and conditional information entropy in formal decision contexts, and they are further used to measure attribute significance. Moreover, an approach is presented to measure the consistency of a formal decision context in preparation for calculating reducts. Finally, heuristic ideas are integrated with reduction technique to achieve the task of calculating reducts of an inconsistent data set.