52 research outputs found

    A hybrid model based on differential fuzzy logic relationships and imperialist competitive algorithm for stock market forecasting

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    In this study, a new kind of fuzzy set in fuzzy time series' field is introduced. It works as a trend estimator to be appropriate for fuzzy time series forecasting by reconnoitering trend of data appropriately. First, the historical data are fuzzified into differential fuzzy sets, and then differential fuzzy relationships are calculated. Second, differential fuzzy logic groups are established by grouping differential fuzzy relationships. Finally, in the defuzzification step, the forecasts are calculated. However, for increasing the accuracy of the models, an evolutionary algorithm, namely imperialist competitive algorithm is injected, to train the model. A massive stock data from four main stock databases have been selected for model validation. The final project, has shown that outperformed its counterparts in term of accuracy

    Image encryption using a synchronous permutation-diffusion technique

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    In the past decade, the interest on digital images security has been increased among scientists. A synchronous permutation and diffusion technique is designed in order to protect gray-level image content while sending it through internet. To implement the proposed method, two-dimensional plain-image is converted to one dimension. Afterward, in order to reduce the sending process time, permutation and diffusion steps for any pixel are performed in the same time. The permutation step uses chaotic map and deoxyribonucleic acid (DNA) to permute a pixel, while diffusion employs DNA sequence and DNA operator to encrypt the pixel. Experimental results and extensive security analyses have been conducted to demonstrate the feasibility and validity of this proposed image encryption method

    Securing Medical Images for Mobile Health Systems Using a Combined Approach of Encryption and Steganography

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    © 2018, Springer International Publishing AG, part of Springer Nature. In this paper, we propose a medical image encryption scheme which can be used in mobile health systems. The proposed scheme combines RSA algorithm, logistic chaotic encryption algorithm, and steganography technique to secure medical images. In the proposed scheme, we encrypt a medical image based on chaotic sequence and encrypt the initial value of the chaotic sequence using the RSA encryption algorithm. The encrypted information by RSA is hidden in the Image. Only legitimate users can obtain the parameter information and restore the image. In the receiver side, we apply the inverse methods to get the original image after an encrypted image is arrived. We have implemented a simple application on the Android platform and have evaluated its performance. The experimental results show that the proposed image encryption scheme is practical and feasible for mobile health systems
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