504 research outputs found

    The project of Hejaz railway construction : a historical and historiographic review

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    One of the last attempts to raise the prestige of the Ottoman caliphate during the reign of Abdul Hamid II was the initiative of the Sultan in the construction of the Hejaz railway, which was to provide an easier and a faster access for pilgrims to the shrines of Mecca and Medina. At the end of the 19th century, as well as during several previous centuries, the main link between the Ottoman administration and the Hejaz residents were the gifts and the donations from the Sultan of the Caliph to religious figures, the sheikhs of the tribes and the population of sacred cities. Of course, such a grandiose construction could aggravate the financial debts of the Ottoman Empire, but, according to preliminary calculations, the road had to pay off, and besides, to glorify Abdul Hamid II. In this regard, the goals and the objectives of this study are to analyze the official ideology of the Ottoman Empire and ideological projects implemented in practice during the reign of Sultan Abdul Hamid II in the form of influence on the social-political situation in the Ottoman Empire, as well as the influence of Islamic unity ideas on Muslims embodied in practice by the carrying out the propaganda campaign for the implementation of the Hijaz railway construction project.peer-reviewe

    Penyisipan Media Teks Dan Citra Menggunakan Teknik Steganografi Pada Media Pembawa Citra Digital

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    Information has now become an important comodity in human life, with the rapid development of communications technology has enable people to communicate and exchange information more easily. Internet is very popular and used by billions users worldwide, the information passing through the internet is very large, and some certain people trying to get this information for profit. The information need to be secured to prevent the others to get the information that send through the internet, steganography can be used to hide the information before sending it and the receiver can recover the hidden data. Digital steganography using computer can use a variety of digital file, digital image file is one of them. With the infomation being hidden inside the image-carrier, the others will not aware about the hidden information. Application created using C# programming leanguage and the steganoraphy method using Least Significant Bit Insertion (LSBI). Microsoft Visual Studio used as Integrated Development Environtment (IDE) to code and design the user interface. Software develpment model using Extreme Programming, and the testing using black box method. Application designed to hide text or image inside an image-carrier and the hidden text or image can be recovered. The result of this research are an application that can hide text or image into image-carrier, and the hidden text or image can be recovered. Based on the testing application can run as expected and fulfill all the requirements

    Lectures on BCOV holomorphic anomaly equations

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    The present article surveys some mathematical aspects of the BCOV holomorphic anomaly equations introduced by Bershadsky, Cecotti, Ooguri and Vafa. It grew from a series of lectures the authors gave at the Fields Institute in the Thematic Program of Calabi-Yau Varieties in the fall of 2013.Comment: reference added, typos correcte

    Solving the Topological String on K3 Fibrations

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    We present solutions of the holomorphic anomaly equations for compact two-parameter Calabi-Yau manifolds which are hypersurfaces in weighted projective space. In particular we focus on K3-fibrations where due to heterotic type II duality the topological invariants in the fibre direction are encoded in certain modular forms. The formalism employed provides holomorphic expansions of topological string amplitudes everywhere in moduli space.Comment: 60 pages, 1 figure, With an appendix by Sheldon Kat

    Calculations for Mirror Symmetry with D-branes

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    We study normal functions capturing D-brane superpotentials on several one- and two-parameter Calabi-Yau hypersurfaces and complete intersections in weighted projective space. We calculate in the B-model and interpret the results using mirror symmetry in the large volume regime, albeit without identifying the precise A-model geometry in all cases. We identify new classes of extensions of Picard-Fuchs equations, as well as a novel type of topology changing phase transition involving quantum D-branes. A 4-d domain wall which is obtained in one region of closed string moduli space from wrapping a four-chain interpolating between two Lagrangian submanifolds is, for other values of the parameters, represented by a disk ending on a single Lagrangian.Comment: 42 page

    Global Properties of Topological String Amplitudes and Orbifold Invariants

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    We derive topological string amplitudes on local Calabi-Yau manifolds in terms of polynomials in finitely many generators of special functions. These objects are defined globally in the moduli space and lead to a description of mirror symmetry at any point in the moduli space. Holomorphic ambiguities of the anomaly equations are fixed by global information obtained from boundary conditions at few special divisors in the moduli space. As an illustration we compute higher genus orbifold Gromov-Witten invariants for C^3/Z_3 and C^3/Z_4.Comment: 34 pages, 3 figure

    Manifestly Supersymmetric RG Flows

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    Renormalisation group (RG) equations in two-dimensional N=1 supersymmetric field theories with boundary are studied. It is explained how a manifestly N=1 supersymmetric scheme can be chosen, and within this scheme the RG equations are determined to next-to-leading order. We also use these results to revisit the question of how brane obstructions and lines of marginal stability appear from a world-sheet perspective.Comment: 22 pages; references added, minor change

    The holomorphic anomaly for open string moduli

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    We complete the holomorphic anomaly equations for topological strings with their dependence on open moduli. We obtain the complete system by standard path integral arguments generalizing the analysis of BCOV (Commun. Math. Phys. 165 (1994) 311) to strings with boundaries. We study both the anti-holomorphic dependence on open moduli and on closed moduli in presence of Wilson lines. By providing the compactification a' la Deligne-Mumford of the moduli space of Riemann surfaces with boundaries, we show that the open holomorphic anomaly equations are structured on the (real codimension one) boundary components of this space.Comment: 1+14 pages, 6 figures! v2: ref. added v3: section 4 expanded, 1+17 pages, 11 figures!!, to be publ. in JHE
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