The possibility of using virtual reality in the field of OSH

Tato bakalářská práce se zabývá možnostmi využití virtuální reality v oblasti bezpečnosti práce. První část popisuje historii a vývoj virtuální reality. Další část práce je zaměřena na hardware a software virtuální reality, možnosti využití a na rozdíly mezi virtuální a rozšířenou realitou. Poté jsou rozebrány požadavky právních a ostatních předpisů vztahujících se k využívání virtuální reality. Závěrečné kapitoly práce se věnují identifikaci možností využití virtuální reality za účelem prevence nehod a úrazů při práci ve firmě Liberty Ostrava a.s.This bachelor thesis deals with the possibilities of using virtual reality in the field of occupational safety and health. The first part describes the history and development of virtual reality. The next part of the work is focused on hardware and software of virtual reality, possibilities of use and on the differences between virtual and augmented reality. Then the requirements of legal and other regulations related to the use of virtual reality are discussed. The final chapters of the thesis are devoted to the identification of the possibilities of using virtual reality in order to prevent accidents and injuries during the work process in Liberty Ostrava a.s.040 - Katedra bezpečnosti práce a procesůvelmi dobř

Effective First Impressions Online: A Case Study of Working With Industry Professionals to Analyze Web Site Usability

The Internet has opened doors for communicators, giving them new ways to reach a variety of audiences in an unfiltered and timely fashion. However, good Web site design is complex, and an unfriendly or confusing site can easily intimidate or discourage users. This paper describes a recent partnership between researchers in academia and an agricultural organization whose aim is to educate the public about the agricultural industry. Together, they used current usability testing methodology to determine the effectiveness of the organization\u27s Web site. This paper presents the results of the study as well as recommendations for individuals considering such a partnership

No apparent accretion mode changes detected in Cen X-3

The presence of two distinct spectral states has previously been reported for Cen X-3 on the basis of RXTE/ASM observations. Triggered by this result, we investigated the spectral properties of the source using the larger amount of X-ray data now available with the aim to clarify and interpret the reported behavior. To check the reported results we used the same data set and followed the same analysis procedures as in the work reporting the two spectral states. Additionally, we repeated the analysis using the enlarged data sample including the newest RXTE/ASM observations as well as the data from the MAXI monitor and from the INTEGRAL/JEM-X and ISGRI instruments. We could not confirm the reported presence of the two spectral states in Cen X-3 either inComment: 4 pages, 6 figures, article is accepted for Astronomy & Astrophysic

The mass of the neutron star in Vela X-1 and tidally induced non-radial oscillations in GP Vel

We report new radial velocity observations of GP Vel/HD77581, the optical companion to the eclipsing X-ray pulsar Vela X-1. Using data spanning more than two complete orbits of the system, we detect evidence for tidally induced non-radial oscillations on the surface of GP Vel, apparent as peaks in the power spectrum of the residuals to the radial velocity curve fit. By removing the effect of these oscillations (to first order) and binning the radial velocities, we have determined the semi-amplitude of the radial velocity curve of GP Vel to be K_o=22.6+/-1.5 km/s. Given the accurately measured semi-amplitude of the pulsar's orbit, the mass ratio of the system is 0.081+/-0.005. We are able to set upper and lower limits on the masses of the component stars as follows. Assuming GP Vel fills its Roche lobe then the inclination angle of the system, i=70.1+/-2.6 deg. In this case we obtain the masses of the two stars as M_x=2.27 +/-0.17 M_sun for the neutron star and M_o=27.9+/-1.3 M_sun for GP Vel. Conversely, assuming the inclination angle is i=90 deg, the ratio of the radius of GP Vel to the radius of its Roche lobe is beta=0.89+/-0.03 and the masses of the two stars are M_x=1.88+/-0.13 M_sun and M_o=23.1+/-0.2 M_sun. A range of solutions between these two sets of limits is also possible, corresponding to other combinations of i and beta. In addition, we note that if the zero phase of the radial velocity curve is allowed as a free parameter, rather than constrained by the X-ray ephemeris, a significantly improved fit is obtained with an amplitude of 21.2+/-0.7 km/s and a phase shift of 0.033+/-0.007 in true anomaly. The apparent shift in the zero phase of the radial velocity curve may indicate the presence of an additional radial velocity component at the orbital period.Comment: Accepted for publication in Astronomy & Astrophysic

X-ray variation statistics and wind clumping in Vela X-1

We investigate the structure of the wind in the neutron star X-ray binary system Vela X-1 by analyzing its flaring behavior. Vela X-1 shows constant flaring, with some flares reaching fluxes of more than 3.0 Crab between 20-60 keV for several 100 seconds, while the average flux is around 250 mCrab. We analyzed all archival INTEGRAL data, calculating the brightness distribution in the 20-60 keV band, which, as we show, closely follows a log-normal distribution. Orbital resolved analysis shows that the structure is strongly variable, explainable by shocks and a fluctuating accretion wake. Analysis of RXTE ASM data suggests a strong orbital change of N_H. Accreted clump masses derived from the INTEGRAL data are on the order of 5 x 10^19 -10^21 g. We show that the lightcurve can be described with a model of multiplicative random numbers. In the course of the simulation we calculate the power spectral density of the system in the 20-100 keV energy band and show that it follows a red-noise power law. We suggest that a mixture of a clumpy wind, shocks, and turbulence can explain the measured mass distribution. As the recently discovered class of supergiant fast X-ray transients (SFXT) seems to show the same parameters for the wind, the link between persistent HMXB like Vela X-1 and SFXT is further strengthened.Comment: 8 pages, 6 figures, accepted for publication in A&

Determination of the mass of the neutron star in SMC X-1, LMC X-4 and Cen X-3 with VLT/UVES

We present the results of a spectroscopic monitoring campaign of the OB-star companions to the eclipsing X-ray pulsars SMC X-1, LMC X-4 and Cen X-3. High-resolution optical spectra obtained with UVES on the ESO Very Large Telescope are used to determine the radial-velocity orbit of the OB (super)giants with high precision. The excellent quality of the spectra provides the opportunity to measure the radial-velocity curve based on individual lines, and to study the effect of possible distortions of the line profiles due to e.g. X-ray heating on the derived radial-velocity amplitude. Several spectral lines show intrinsic variations with orbital phase. The magnitude of these variations depends on line strength, and thus provides a criterion to select lines that do not suffer from distortions. The undistorted lines show a larger radial-velocity amplitude than the distorted lines, consistent with model predictions. Application of our line-selection criteria results in a mean radial-velocity amplitude K(Opt) of 20.2 +/- 1.1, 35.1 +/- 1.5, and 27.5 +/- 2.3 km/s (1 sigma errors), for the OB companion to SMC X-1, LMC X-4 and Cen X-3, respectively. Adding information on the projected rotational velocity of the OB companion (derived from our spectra), the duration of X-ray eclipse and orbital parameters of the X-ray pulsar (obtained from literature), we arrive at a neutron star mass of 1.06^{+0.11}_{-0.10}, 1.25^{+0.11}_{-0.10} and 1.34^{+0.16}_{-0.14} M{sun} for SMC X-1, LMC X-4 and Cen X-3, respectively. The mass of SMC X-1 is near the minimum mass (~1 M{sun}) expected for a neutron star produced in a supernova. We discuss the implications of the measured mass distribution on the neutron-star formation mechanism, in relation to the evolutionary history of the massive binaries.Comment: Accepted for publication in Astronomy and Astrophysic

The Properties of X-Ray and Optical Light Curves of X-Ray Novae

We have collected the available data from the literature and from public data archives covering the past two decades for the long-term X-ray and optical light curves of X-ray nova (XN) outbursts, and carry out for the first time a systematic, statistical study of XN light curves which are classified into 5 morphological types. Basic light curve parameters, e.g., the outburst peak flux, amplitude, luminosity, rise and decay timescales, the observed and expected outburst durations, and total energy radiated, are tabulated and discussed. The rise timescales are found to have a flat distribution while the decay timescales have a much narrower and near-Gaussian distribution, centered around 30 days and dominated by the strongest outbursts. The peak luminosity is also distributed like a Gaussian, centered around 0.2 in Eddington units, while the total energy released has a much broader distribution around 10E44 ergs. We identify and discuss additional light curve features, such as precursors, plateaus, and secondary maxima. The plateaus exhibited in the light curves of black hole sources are found to have, on average, longer durations and they are followed by longer decays. The identified secondary maxima seem to occur mostly in black hole systems. For the frequency of outbursts, we find that the average XN outburst rate is about 2.6 per year for events >0.3 Crab, and that the mean recurrence time between outbursts from a single source is 6 years. The spatial and logN-logS distribution of the XN sources, with limited statistics, agrees with a source population in the Galactic disk, as observed from a point at a distance of 8.5 kpc from the Galactic center. Finally, we point out that the observed XN light curve properties can in general be explained by a disk thermal instability model, although some important problems still remain.Comment: 68 pages including 27 Postscript figures and 12 tables. To be published in the Astrophysical Journal, Part

Technology implementation of construction of roof cover

Import 03/08/2012Bakalářská práce je zaměřena na popis použití moderní drážkové tašky s hlubokým dvojitým drážkováním, které vytváří velmi odolnou ochranu proti povětrnostním vlivům – střešní krytiny TONDACH STODO 12. Ve své práci popisuji pracovní popis montáže střechy s vybranou střešní krytinou, dále jsem zpracoval technickou zprávu a technologický předpis provádění zvolené střešní krytiny TONDACH. Součástí mé bakalářské práce je rozpočet a harmonogram provádění. Další část mé práce tvoří výkresová dokumentace důležitých částí objektu. Závěrem své práce jsem zhodnotil výběr zvolené střešní krytiny.The thesis is focused to describe using modern roof tiles with a deep doubled grooving, which creates a very durable weather protection – roof tile TONDACH STODO 12. In my thesis, I described a procedure of roof installation for selected roof tile; I also prepared a technical report and technological instructions for selected roof tile – TONDACH. Price estimate and working schedule is also part of my thesis as well as drawings with important parts of the building. Conclusion of my work is to evaluate my selection of roof tile.Prezenční225 - Katedra pozemního stavitelstvívýborn

Addressing employees' turnover through the implementation of new measures of employees' loyalty at Koyo Bearings Czech Republic s.r.o.

Diplomová práce je zaměřená na problematiku řešení fluktuace zaměstnanců prostřednictvím implementace nových opatření ke zvýšení loajality zaměstnanců v podniku Koyo Bearings Česká republika s.r.o. (Koyo). Práce je rozdělená do pěti částí. První část se zabývá teoretickým vymezením problematiky fluktuace a činností, pomocí kterých dle různých autorů lze dosáhnout zvýšení loajality. Druhá část práce pojednává o analýze současného stavu fluktuace zaměstnanců v podniku Koyo, kde jsou zpracovaná data o odchodu zaměstnanců za období 2017 a 2018. Třetí část se zabývá analýzou současného stavu loajality zaměstnanců v podniku Koyo, ve které je rozebráno dotazníkové šetření. Na základě výstupů předchozích částí práce se čtvrtá část zabývá implementací nových opatření ke zvýšení loajality zaměstnanců v podniku Koyo. Poslední část práce pojednává o zhodnocení navrhovaných opatření.The diploma thesis focuses on the issue of dealing with employees' turnover through the implementation of new measures to increase employees' loyalty in the company Koyo Bearings Czech Republic s.r.o. (Koyo). The thesis is divided into five parts. The first part deals with the theoretical definition of fluctuation issues and activities, according to which various authors can achieve increased loyalty. The second part of the thesis contains the analysis of the current state of employees' turnover in the company Koyo, where the data on employees' leaving their employment for the period 2017 and 2018 are visible. The third part shows the analysis of the current state of employees' loyalty in the company Koyo, which is being analyzed by the questionnaire survey. Based on the outcomes of the previous parts of the thesis, the fourth part describes the implementation of new measures to increase employees' loyalty in Koyo. The last part of the thesis presents the evaluation of the proposed measures.Dopravní fakulta Jana PerneraDiplomant přednesl ucelenou a logicky uspořádanou obhajobu své diplomové práce. V ní dokázal přesvědčivým způsobem obhájit závěry svých řešení. Na poznámky, resp. připomínky oponenta reagoval správně a v plném rozsahu je zodpověděl. U doplňkových otázek prokázal schopnost logického myšlení, pohotové reakce, jasného a srozumitelného vysvětlení.Dokončená práce s úspěšnou obhajobo