Yazar "Alsaidi, Nadia M. G." seçeneğine göre listele

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    The effect of harvesting policy on an eco-epidemiological model
    (Maltepe Üniversitesi, 2019) Al-Jubourili, Karar Q.; Hussien, Reem M.; Alsaidi, Nadia M. G.
    Considering to the high extent spread of epidemics in the general of individuals of the miserable communities that causes of extinction, we suggested and investigated an eco-epidemiological system consisting two different (SIS and SI) infectious diseases in prey population, which are transmitted within prey species by the contact. The selective optimal harvesting on predator species is proposed and analyzed. The mathematical model involves four first-order nonlinear ordinary differential equations, which characterized the interaction among the susceptible prey, infected prey, and predator. The predator feeding depends on predation prey according to Holling type-II functional response, as well as, the nonlinear incidence for describing the transition of infectious diseases is used. The existence of bionomic equilibria, uniqueness, boundedness of the system solution and the optimal proportionate harvesting policy are discussed
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    Image encryption based on highly sensitive chaotic system
    (Maltepe Üniversitesi, 2019) Ali, Dalia S.; Alwan, Nawras A.; Alsaidi, Nadia M. G.
    In the recent past, various algorithms for image encryption is introduced based on chaotic systems, some of them appeared weak in some points such as, resisting the chosen plaintext attack and the chosen ciphertext attack with low sensitivity to change of plain images. To overcome such weaknesses, this article proposes a new two-dimensional (2D) hyperchaotic system, which is derived from three maps namely; Henon, logistic, iterative chaotic map with infinite collapse (ICMIC) maps. The performance analysis of this system shows high sensitivity to the initial condition, complicated dynamics, hyperchaotic properties, and better ergodicity. The proposed system is adopted in the design of a new image encryption algorithm. The encryption process is mainly depending on changing of eigenvalues and eigenvectors of original image utilizing a function to change the intensity of pixels, the plain-image is divided into blocks to generate four different keys (multi-key) based on the proposed hyperchaotic system to increase the complexity and reduce the computation time. The partitioned process is repeated several times for each block before obtaining an encrypted image, where the new block in each iteration is multiplied with the four different generated keys. Eventually, to show the efficiency of the encryption image, some performance analysis tests are performed such as; image histogram, NPCR, UACI and pixels correlation.
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    A new pseudo random bits generator via 2D chaotic system, diffusion, and permeation
    (Maltepe Üniversitesi, 2019) Farhan, Alaa Kadhim; Tariq, Abeer; Ali, Rasha S.; Alsaidi, Nadia M. G.
    Recently a remarkable correlation between chaos and cryptography has been established. Due to this close correlation, numerous chaos based cryptographic systems were developed during the past years. Some of these cryptosystems are based on the 1D chaotic maps and the others are based on the 2D chaotic maps. The former has limited efficiency and security due to their limited space of the secret key; consequently the regions that exhibit chaotic behaviors are also limited. This limitation problem is a significant disadvantage in the security field. Therefore the current study proposed a new pseudo random bit generator (BRBG) based on new 2D chaotic logistic maps that run side-by-side and start from random independent initial states. The structure of the proposed model consists of three components: firstly, a mouse device as the non-deterministic input sources, secondly, the proposed 2D chaotic system, and thirdly, an initial permutation (IP) table. The statistical tests of the generated sequences of bits are investigated by applying of NIST, which is the most strict statistical test utilized for specifying of purely random sequences.
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    Secure optical communication based on new 2D-hyperchaotic map
    (Maltepe Üniversitesi, 2019) Younus, Dhurgham; Alsaidi, Nadia M. G.; Hamoudi, Walid K.
    Chaos-based cryptography is considered as a preferred way in transferring and processing of the data through different unsecured channels; one of them is the optical channel. The reason behind this important is because of non-periodic chaotic signals; their behavior is nonlinear in addition to their sensitivity to initial conditions, which grant chaos great important in measuring the unpredictability and randomness. These properties conduct that; the designed system must possess high complexity. Therefore, designing a non-linear system satisfying the aforementioned properties is of high demand. Derived from the existing 1D-sine map, a new nonlinear 2D-adjusted sine map is intended to generate a hyperchaotic behavior; its dynamical properties are studied in term of fixed points, Jacobian eigenvalues, trajectory, Lyapunov exponent, and bifurcation diagram. The complexity of the 2D-adjusted sine map is investigated using the Approximate Entropy (AE). The generated chaotic signal is modulated with the message and sent as a binary sequence through an optical channel.