Phenomenological modelling of eclipsing system light curves

The observed light curves of most eclipsing binaries and stars with transiting planets can be well described and interpreted by current advanced physical models which also allow for the determination of many physical parameters of eclipsing systems. However, for several common practical tasks there is no need to know the detailed physics of a variable star, but only the shapes of their light curves or other phase curves. We present a set of phenomenological models for the light curves of eclipsing systems. We express the observed light curves of eclipsing binaries and stars, transited by their exoplanets orbiting in circular trajectories, by a sum of special, analytical, few-parameter functions that enable fitting their light curves with an accuracy of better than 1%. The proposed set of phenomenological models of eclipsing variable light curves were then tested on several real systems. For XY Bootis, we also compare in details the results obtained using our phenomenological modelling with those found using available physical models. We demonstrate that the proposed phenomenological models of transiting exoplanet and eclipsing binary light curves applied to ground-based photometric observations yields results compatible with those obtained by the application of more complex physical models. The suggested phenomenological modelling appears useful to solve a number of common tasks in the field of eclipsing variable research.Comment: 13 pages, 14 figures. To appear in Astronomy and Astrophysics, 201

Effect of Supply Voltage Waveform to Measure the Current through the Coil Current Measurement

Cílem této práce je porovnat rozdíl mezi měřením proudu přímou a nepřímou metodou při použití vzduchové měřicí cívky proudu. Jedná se o to, zda měřicí vzduchová cívka způsobuje chyby měření různých harmonických a neharmonických průběhů, a zda se přímo na cívce zvětšuje proud o počet závitů N, nebo při měření vzniká nějaká chyba. Hlavním úkolem je porovnat, jestli jsou obě metody měření vhodné k měření harmonických a neharmonických proudů.The aim of this study is to compare the difference between the current measurement, direct and indirect method of measuring air ingestion coil current. It is about whether measuring air coil causes measurement errors of different harmonic and non-harmonic waveforms, and whether directly on the coil current increases the number of turns N, or when there is an error measurement. The main task is to compare whether both measurement methods are suitable for measuring harmonic and non-harmonic currents.450 - Katedra kybernetiky a biomedicínského inženýrstvívelmi dobř

Active aerodynamic components of automobiles

Tato bakalářská práce se zabývá vypracováním rešerše na téma aktivní aerodynamické prvky. Práce nás nejprve seznámí se základy aerodynamiky a tvorbou vztlakové síly. Popisuje jednotlivé aktivní aerodynamické prvky, které jsou využívány v automobilech pro zajištění lepších jízdních vlastností.This bachelor’s thesis is focused on the topic of active aerodynamic components. Bachelor’s thesis explains something about the basics of aerodynamics and generating aerodynamic forces. It also describes the main active aerodynamic components, which are used in automobiles for better driveability.

Hi-fi phenomenological description of eclipsing binary light variations as the basis for their period analysis

In-depth analysis of eclipsing binary (EB) observational data collected for several decades can inform us about a lot of astrophysically interesting processes taking place in the systems. We have developed a wide-ranging method for the phenomenological modelling of eclipsing binary phase curves that enables us to combine even very disparate sources of phase information. This approach is appropriate for the processing of both standard photometric series of eclipses and data from photometric surveys of all kind. We conclude that mid-eclipse times, determined using the latest version of our 'hi-fi' phenomenological light curve models, as well as their accuracy, are nearly the same as the values obtained using much more complex standard physical EB models.Comment: 4 pages, 3 figures, EAS - Proceedings of the conference: Setting a new standard in the analysis of binary stars, 16 to 19 September 2013, Leuven, Belgiu