Selecting E-Commerce Information System

Tato diplomová práce se zabývá výběrem informačního systému pro elektronický obchod Lepime.cz. Předmětem prodeje jsou bytové dekorace - samolepky na zeď vyráběné na míru. V první části je představena firma, výrobek a nastíněna analýza současného stavu informačního systému s důrazem na sestavení specifikace požadavků. Na tomto základě jsou pak porovnány jednotlivé informační systémy, které se dostaly do užšího výběru. Stěžejní částí je ekonomické srovnání informačních systémů, jak z hlediska počáteční investice, tak následných nákladů na jeho provoz.This master’s thesis focuses on selecting an information system for the e-commerce site Lepime.cz. This e-shop sells home decorations – customized wall stickers. In the first part I am introducing the company, product, creating an analysis of the current information system and putting together the requirements and specifications. The second part is focusing on comparing considerable information systems, which were pre-selected to a shortlist. The key part compares the information systems economically, based on the required initial investments and monthly service fees.

Correction of UBV photometry for emission lines

We investigated the effect on the U, B, V magnitudes of the removal of the emission lines from the spectra of some symbiotic stars and novae during their nebular phases. We approached this problem by a precise reconstruction of the composite UV/optical continuum and the line spectrum. Corrections DU, DB, DV are determined from the ratio of fluxes with and without emission lines. Here we demonstrate this effect on the case of the symbiotic nova V1016 Cyg during its nebular phase. We find that about 68, 78 and 66 per-cent of the observed flux in the U, B and V filters is radiated in the emission lines. The effect should be taken into account before using the observed color indices of emission-line objects for diagnosis of their radiation in the continumm.Comment: 6 pages, 3 Figure

Multiwavelength evidence for a 15-year periodic activity in the symbiotic nova V1016 Cygni

The ~15.1 years period found in the long-term UBV photoelectric and photographic photometry of the symbiotic nova V1016 Cyg is detected also in the (J-K) colour index and in the UV continuum and emission line fluxes from IUE and HUT spectra. It could be interpreted either as the effect of recurrent enhanced mass loss episodes from the Mira type variable companion to a hot component along its ultra-wide orbit (proposed from recent HST observations) or the true orbital period of the inner, unresolved binary of a triple system. A 410-day delay of the maximum of UV emission lines fluxes with respect to the maximum of continuum was found. The pulsation period of the Mira type variable was improved to 474+/-6 days.Comment: 7 pages, 7 PostScript figures. Accepted for pubblication in A&

Recent photometry of symbiotic stars - XII

We present new photometric observations of 15 symbiotic stars (EG And, Z And, AE Ara, BF Cyg, CH Cyg, CI Cyg, V1329 Cyg, TX CVn, AG Dra, Draco C-1, RW Hya, SY Mus, AR Pav, AG Peg, AX Per) covering their last orbital cycle(s) from 2003.9 to 2007.2. We obtained our data by both classical photoelectric and CCD photometry. Main results are: EG And brightened by about 0.3 mag in U from 2003. A 0.5 mag deep primary minimum developed in the U light curve (LC) at the end of 2006. Z And continues its recent activity that began during the 2000 autumn. A new small outburst started in summer of 2004 with the peak U-magnitude of about 9.2. During the spring of 2006 the star entered a massive outburst. It reached its historical maximum at U = 8.0 in 2006 July. AE Ara erupted in 2006 February with Dm(vis) approx. 1.2 mag. BF Cyg entered a new active stage in 2006 August. A brightness maximum (U approx. 9.4) was measured during 2006 September. CH Cyg persists in a quiescent phase. During 2006 June - December about 2 mag decline in all colours was measured. CI Cyg started a new active phase during 2006 May - June. After 31 years it erupted by about 2 mag in U. TX CVn maintains a bright stage with U approx. 10.5 from 2003. AG Dra entered a new major outburst in 2006 June. It reached its maximum at U = 8.0 in 2006 September. AR Pav persists at a low level of the activity. AG Peg's LC profile varies markedly during different orbital cycles. AX Per continues its quiescent phase.Comment: 4 pages text, 12 figures, 18 tables, accepted for publication in Astron. Nachrichte

The O I] 1641A line as a probe of symbiotic star winds

The neutral oxygen resonance 1302A line can, if the optical depth is sufficiently high, de-excite by an intercombination transition at 1641A to a metastable state. This has been noted in a number of previous studies but never systematically investigated as a diagnostic of the neutral red giant wind in symbiotic stars and symbiotic-like recurrent novae. We used archival $IUE$ high resolution, and GHRS and STIS medium and high resolution, spectra to study a sample of symbiotic stars. The integrated fluxes were measured, where possible, for the O I 1302A and O I] 1641A lines. The intercombination 1641A line is detected in a substantial number of symbiotic stars with optical depths that give column densities comparable with direct eclipse measures (EG And) and the evolution of the recurrent nova RS Oph 1985 in outburst. In four systems (EG And, Z And, V1016 Cyg, and RR Tel), we find that the O I] variations are strongly correlated with the optical light curve and outburst activity. This transition can also be important for the study of a wide variety of sources in which an ionization-bounded H II region is imbedded in an extensive neutral medium, including active galactic nuclei, and not only for evaluations of extinction.Comment: accepted for publication in Astronomy and Astrophysics (2010 Feb. 23), in press, NASA-GSFC-Code 66