Yazar "Yilmaz, Ihsan" seçeneğine göre listele

Listeleniyor 1 - 19 / 19
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    A novel quantum steganography algorithm based on LSBq for multi-wavelength quantum images
    (Springer, 2018) Sahin, Engin; Yilmaz, Ihsan
    In this study, a novel quantum steganography algorithm based on LSBq for multi-wavelength quantum images is proposed. In this study, both the text and the binary image messages are embedded into the cover image. The results of simulations and analysis show that our algorithm satisfies the requirements of steganography algorithms. Also, we used modulo method and Hilbert scrambling method for the security of the hidden message. It is seen that an unauthorized person obtains meaningless information when attempting to extract a embedded information through known methods. The results show that the algorithm is robust against attack when several attacks are applied on the stego-image. Finally, we compare our proposed algorithm with the related works. The results of simulation show that the our proposed algorithm has many advantages according to the related algorithms.
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    Edtergy-momentum problem in general relativity and tele-parallel gravity for string and domain wall
    (Jagiellonian Univ Press, 2007) Ayguen, Melis; Yilmaz, Ihsan
    This study is purposed to elaborate the problem of energy and momentum distribution of string and domain wall in the context of two different approaches of gravity such as general relativity and tele-parallel gravity. In this connection, we have calculated energy-momentum of domain wall and string by using the energy-momentum definitions of Einstein, Bergmann-Thomson and Landau-Lifshitz in general relativity and tele-parallel gravity. In our analysis we obtained that (i) general relativity and tele-parallel gravity are equivalent theories for string and domain wall (ii) different energy-momentum complexes do not provide the same energy and momentum densities neither in general relativity nor in tele-parallel gravity for domain wall.
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    Energy and momentum of Rigidly Rotating Wormhole space-time
    (Wydawnictwo Uniwersytetu Jagiellonskiego, 2006) Aygun, Melis; Yilmaz, Ihsan; Aygun, Sezgin
    This study is purposed to elaborate the problem of energy and momentum distribution of the Rigidly Rotating Wormhole space-time in general theory of relativity. In this connection, we use the energy-momentum definitions of Einstein, Bergmann-Thomson and Tolman. We obtained that the energy and momentum distributions of Einstein, Bergmann-Thomson and Tolman definitions give the same results in Rigidly Rotating Wormhole space-time.
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    Energy of rigidly rotating wormhole space-time
    (Amer Inst Physics, 2007) Ayguen, Melis; Yilmaz, Ihsan; Ayguen, Sezgin
    This study is purposed to elaborate the problem of energy distribution of the Rigidly Rotating Wormhole space-time in general theory of relativity. In this connection, we use the energy-momentum definitions of Einstein, Bergmann-Thomson and Tolman. We obtained that the energy distributions of Einstein, Bergmann-Thomson and Tolman definitions give the same results in Rigidly Rotating Wormhole space-time.
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    Energy-momentum distributions of Hawking wormholes
    (Springer/Plenum Publishers, 2008) Aygun, Melis; Yilmaz, Ihsan
    This study is purposed to elaborate the problem of energy and momentum distributions of the Hawking wormholes in general theory of relativity and teleparallel gravity. In this connection, the energy and momentum for the Hawking wormhole space-time are evaluated using Einstein, Bergmann-Thomson, Landau-Lifshitz and Moller energy-momentum prescriptions in these approximations. We obtained that some of these energy-momentum distributions of Hawking wormhole in the form of general relativity (GR) and teleparallel gravity (TG) give the same results. Also, we obtained that in the teleparallel gravity, Moller energy distributions of the Hawking wormholes give the same results as Einstein energy distributions. However, Bergmann-Thomson and Landau-Lifshitz energy-momentum of Hawking wormholes are the different from each others.
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    Energy-momentum problem in general relativity and tele-parallel gravity for string and domain wall
    (2007) Aygün, Melis; Yilmaz, Ihsan
    This study is purposed to elaborate the problem of energy and momentum distribution of string and domain wall in the context of two different approaches of gravity such as general relativity and tele-parallel gravity. In this connection, we have calculated energy-momentum of domain wall and string by using the energy-momentum definitions of Einstein, Bergmann-Thomson and Landau-Lifshitz in general relativity and tele-parallel gravity. In our analysis we obtained that (i) general relativity and tele-parallel gravity are equivalent theories for string and domain wall (ii) different energy-momentum complexes do not provide the same energy and momentum densities neither in general relativity nor in tele-parallel gravity for domain wall.
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    Expanding and nonexpanding conformal wormholes in scalar-tensor theory
    (World Scientific Publ Co Pte Ltd, 2015) Dogru, Melis Ulu; Yilmaz, Ihsan
    We study spherically symmetric spacetime with anisotropic fluid in the scalar-tensor theory of gravity based on Lyra geometry. We suggest two different solutions of field equations for the theory by using Casimir effect. Obtained static and nonstatic solutions are similar to nonexpanding Lorentzian wormhole and expanding FRW-type wormhole, respectively. Furthermore, we study singularities of obtained solutions. We emphasize whether the expanding and nonexpanding wormholes conform with Big Rip or Big Crunch scenarios. Also, physical and geometrical properties of the solutions have been discussed.
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    High-dimensional Grover multi-target search algorithm on Cirq
    (Springer Heidelberg, 2022) Acar, Erdi; Gunduz, Sabri; Akpinar, Guven; Yilmaz, Ihsan
    High-dimensional computing, compared to traditional qubit computing, has the advantage of operating in a larger scale and storing more information. Considering its advantages, it is of great importance to adapt existing quantum algorithms to high dimension for quantum computing. Yet, the challenges pertaining to high-dimensional quantum computing have limited the studies in this field. In this study, the Grover Search Algorithm for two, three and four targets in high dimension is implemented on Cirq. We concluded that computing in high dimension provides an advantage in terms of capacity and number of qudits used.
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    Higher-dimensional cosmological models with strange quark matter
    (World Scientific Publ Co Pte Ltd, 2006) Yilmaz, Ihsan; Yavuz, Attila Altay
    In this article, we study higher-dimensional cosmological models with quark-gluon plasma in the context of general relativity. For this purpose, we consider quark-gluon plasma as a perfect fluid in the higher-dimensional universes. After solving Einstein's field equations, we have analyzed this matter for the different types of universes in the higher- and four-dimensional universes. Also, we have discussed the features of obtained solutions.
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    Moller energy complexes of monopoles and textures in general relativity and teleparallel gravity
    (Iop Publishing Ltd, 2007) Aygun, Melis; Yilmaz, Ihsan
    The energy problem of monopole and texture spacetimes is investigated in the context of two different approaches of gravity such as general relativity and teleparallel gravity. In this connection, firstly the energies for monopoles and textures are evaluated by using the Moller energy momentum prescription in different approximations. It is obtained that energy distributions of Moller definition give the same results for these topological defects (monopole and texture) in general relativity (GR) and teleparallel gravity (TG). The results strengthen the importance of the Moller energy momentum definitions in given spacetimes and the viewpoint of Lessner that Moller energy momentum complex is a powerful concept for energy and momentum.
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    Multi-Partied Quantum Digital Signature Scheme Without Assumptions On Quantum Channel Security
    (Iop Publishing Ltd, 2016) Sahin, Mustafa; Yilmaz, Ihsan
    In this study, we generalized quantum digital signature scheme for three-partied[5] to the multi-partied. Also we analyzed this scheme for repudiation, forgery and colluding adversaries.
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    Plagiarism? No, we're just borrowing better English
    (Nature Publishing Group, 2007) Yilmaz, Ihsan
    [Anstract Not Available]
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    QRMA: quantum representation of multichannel audio
    (Springer, 2019) Sahin, Engin; Yilmaz, Ihsan
    In this study, quantum representation of multichannel adio (QRMA) that can be used in many fields in future is proposed. The QRMA uses three entangled qubit sequences where time, channel, negative and positive amplitude values can be stored. The three-qubit sequences are in basis state: |0 and |1. The preparation of the QRMA starting from the initial state |0 is presented. In addition, multichannel audio is obtained from the QRMA quantum state. Several operations such as signal merging, signal addition, signal inversion, signal reversal, channel merging and channel reversal are studied on the QRMA. The simulations and the analyses show that the QRMA has more advantages than the other models in the literature.
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    QRMW: quantum representation of multi wavelength images
    (Tubitak Scientific & Technological Research Council Turkey, 2018) Sahin, Engin; Yilmaz, Ihsan
    In this study, we propose quantum representation of multiwavelength images (QRMW) that gives preparation and retrieving procedures of quantum images. The proposed QRMW model represents multichannel and 2(n) x 2(m) images. Moreover, we present image comparison and some image operations based on the QRMW model. Comparing our model with the models in the literature, the QRMW model has less time complexity. It also uses fewer qubits than existing models in the literature.
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    Some information from thermodynamic curvature of Chaplygin gas
    (World Scientific Publ Co Pte Ltd, 2019) Turkgenc, Emine; Yilmaz, Ihsan
    In this paper, we study thermodynamic curvature of Chaplygin gas which is one of the dark energy candidates in terms of entropy and temperature. So, we get some information about past universe by considering thermodynamic curvature of Chaplygin gas. In addition to thermodynamic curvature, we study behaviors of test particle in the universe filled with Chaplygin gas.
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    Some string cosmological models in cylindrically symmetric inhomogeneous universe
    (2001) Baysal, Hüsnü; Yavuz, Ilhami; Tarhan, Ismail; Camci, U?ur; Yilmaz, Ihsan
    The aim of this paper is to investigate the behavior of a string in the cylindrically symmetric inhomogeneous cosmological model. It has been assumed that expansion ? in the model is proportional to ?11 of the eigenvalue of the shear tensor ??mu;. Also, various physical and geometrical properties of the model have been discussed.
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    The behavior of the strange quark matter in the FRW universes
    (World Scientific Publ Co Pte Ltd, 2007) Yilmaz, Ihsan; Kucukarslan, Ayse; Ozder, Serhat
    In this paper, we study strange quark matter for Friedman - Robertson - Walker (FRW) universes in the context of general relativity. For this purpose we consider quark - gluon plasma as a perfect fluid in the FRW universes. After solving Einstein's field equations, we have analyzed this matter for the different types of universe. Also, we discuss the features of collapsing strange quark matter.
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    The Moller energy complexes of various wormholes in general relativity and Teleparallel gravity
    (Springer/Plenum Publishers, 2007) Ayguen, Melis; Yilmaz, Ihsan
    This study is aimed to elaborate the energy problem of general wormhole space-times in two different approaches of gravity such as general relativity and teleparallel gravity. In this connection, the energy for well-known wormhole space-times is evaluated using Moller energy-momentum prescription in these different approximations. We obtained that energy distributions of Moller definition give the same results for various wormhole space-times in general relativity (GR) and teleparallel gravity (TG). The results strengthen the importance of Moller energy-momentum definitions in given space-times and viewpoint of Lessner that Moller energy-momentum complex is a powerful concept for energy and momentum.
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    Timelike and spacelike Ricci collineation vectors in string fluid
    (2003) Baysal, Hüsnü; Yilmaz, Ihsan
    We study the consequences of the existence of timelike and spacelike Ricci collineation vectors (RCVs) for string fluid in the context of general relativity. Necessary and sufficient conditions are derived for a space-time with string fluid to admit a timelike RCV, parallel to ua, and a spacelike RCV, parallel to na. In these cases, some results obtained are discussed.