925 research outputs found

    Tax Documentation System for Linux

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    Tato bakal√°Ňôsk√© pr√°ce pojedn√°v√° o n√°vrhu a implementaci syst√©mu slouŇĺ√≠c√≠ho pro jednoduch√© veden√≠ daŇąov√© evidence v operańćn√≠m syst√©mu GNU/Linux. Aplikace je vytvoŇôena pomoc√≠ grafick√© knihovny wxWidgets pŇôińćemŇĺ uŇĺivatelsk√° data jsou Ň°ifrovanńõ ukl√°d√°na do SQLite datab√°ze. V prvn√≠ kapitole pr√°ce je probr√°n souńćasn√Ĺ stav programŇĮ pro veden√≠ daŇąov√© evidence v OS GNU/Linux a c√≠le navrŇĺen√© aplikace. Na ni navazuje ńć√°st popisuj√≠c√≠ pojmy a postupy nutn√© k porozumńõn√≠ a veden√≠ daŇąov√© evidence dle platn√Ĺch z√°konŇĮ. N√°sleduj√≠c√≠ kapitoly se zab√Ĺvaj√≠ vlastn√≠m n√°vrhem a implementac√≠ syst√©mu. Z√°vńõr pr√°ce je vńõnov√°n zhodnocen√≠ pŇô√≠nosu navrŇĺen√© aplikace a nast√≠nńõn√≠ smńõru jej√≠ho dalŇ°√≠ho v√Ĺvoje.This thesis is about concept and implementation of a system uses for simple tax account management in GNU/Linux operating systems. The application has been created by wxWidgets tools library and user's data are saved and encrypted into a SQLite database. Present situation of programs for tax account management under GNU/Linux systems and the goals of this concept are described in the first chapter. The next chapter is describing terms and procedures which are necessary for understanding of tax account management according law. Other chapters deal with the concept itself and the implementation. Conclusion of the thesis is devoted to a review of benefits and further development of the concept.

    On the 511 keV emission line of positron annihilation in the Milky Way

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    I review our current understanding of positron sources in the Galaxy, on the basis of the reported properties of the observed 511 keV annihilation line. It is argued here that most of the disk positrons propagate away from the disk and the resulting low surface brightness annihilation emission is currently undetectable by SPI/INTEGRAL. It is also argued that a large fraction of the disk positrons may be transported via the regular magnetic field of the Galaxy into the bulge and annihilate there. These ideas may alleviate current difficulties in interepreting INTEGRAL results in a "conventional" framework.Comment: 7 pages, 2 figures, paper presented in "Astronomy with Radioactivities" (Ringberg, Germany, january 2008), to appear in New Astronomy Review

    Magnetic fields of our Galaxy on large and small scales

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    Magnetic fields have been observed on all scales in our Galaxy, from AU to kpc. With pulsar dispersion measures and rotation measures, we can directly measure the magnetic fields in a very large region of the Galactic disk. The results show that the large-scale magnetic fields are aligned with the spiral arms but reverse their directions many times from the inner-most arm (Norma) to the outer arm (Perseus). The Zeeman splitting measurements of masers in HII regions or star-formation regions not only show the structured fields inside clouds, but also have a clear pattern in the global Galactic distribution of all measured clouds which indicates the possible connection of the large-scale and small-scale magnetic fields.Comment: 9 pages. Invited Talk at IAU Symp.242, 'Astrophysical Masers and their Environments', Proceedings edited by J. M. Chapman & W. A. Baa

    Evaluation of scientific CMOS sensors for sky survey applications

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    Scientific CMOS image sensors are a modern alternative for a typical CCD detectors, as they offer both low read-out noise, large sensitive area, and high frame rates. All these makes them promising devices for a modern wide-field sky surveys. However, the peculiarities of CMOS technology have to be properly taken into account when analyzing the data. In order to characterize these, we performed an extensive laboratory testing of Andor Marana sCMOS camera. Here we report its results, especially on the temporal stability and linearity, and compare it to the previous versions of Andor sCMOS cameras. We also present the results of an on-sky testing of this sensor connected to a wide-field lens, and discuss its applications for an astronomical sky surveys.Comment: Accepted to Astronomische Nachrichte

    Magnetic structure of our Galaxy: A review of observations

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    The magnetic structure in the Galactic disk, the Galactic center and the Galactic halo can be delineated more clearly than ever before. In the Galactic disk, the magnetic structure has been revealed by starlight polarization within 2 or 3 kpc of the Solar vicinity, by the distribution of the Zeeman splitting of OH masers in two or three nearby spiral arms, and by pulsar dispersion measures and rotation measures in nearly half of the disk. The polarized thermal dust emission of clouds at infrared, mm and submm wavelengths and the diffuse synchrotron emission are also related to the large-scale magnetic field in the disk. The rotation measures of extragalactic radio sources at low Galactic latitudes can be modeled by electron distributions and large-scale magnetic fields. The statistical properties of the magnetized interstellar medium at various scales have been studied using rotation measure data and polarization data. In the Galactic center, the non-thermal filaments indicate poloidal fields. There is no consensus on the field strength, maybe mG, maybe tens of uG. The polarized dust emission and much enhanced rotation measures of background radio sources are probably related to toroidal fields. In the Galactic halo, the antisymmetric RM sky reveals large-scale toroidal fields with reversed directions above and below the Galactic plane. Magnetic fields from all parts of our Galaxy are connected to form a global field structure. More observations are needed to explore the untouched regions and delineate how fields in different parts are connected.Comment: 10+1 pages. Invited Review for IAU Symp.259: Cosmic Magnetic Fields: From Planets, to Stars and Galaxies (Tenerife, Spain. Nov.3-7, 2009). K.G. Strassmeier, A.G. Kosovichev & J.E. Beckman (eds.
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