Since the number of internet users is increasing and sensitive information is exchanging continuously, data security has become a problem. Image steganography is one of the ways to exchange secret data securely using ...
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Since the number of internet users is increasing and sensitive information is exchanging continuously, data security has become a problem. Image steganography is one of the ways to exchange secret data securely using images. However, several issues need to be mitigated, especially in the imperceptibility (security) aspect, which is the process of embedding secret data in the images that can be vulnerable to attacks. This paper focuses on developing a secure method for hiding secret messages in an image, based on the standard Least Significant Bit (LSB). Before proceeding with the embedding stage, the secret message's size is reduced by compression using the Huffman algorithm, followed by two operations, which are the Boolean operation Exclusive-NOR (XNOR) operation and the fibonacci algorithm when selecting pixels to embed the secret message. As a result of these processes, a stego-image is created with two secret keys. We obtained promising results against standard images with higher Peak Signal-to-Noise Ratio (PSNR) values of 66.6170, 65.8928, and 65.9386 dB for ***, ***, and ***, respectively, as compared to other state-of-the-art schemes. The evaluation stage proves the increasing level of security as well as imperceptibility.
The reliability testing method for subway trains acceptance based on Bayesian theory mainly uses prior information, the data of reliability testing for qualification acceptance, and the posterior information is obtain...
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ISBN:
(纸本)9781538653807
The reliability testing method for subway trains acceptance based on Bayesian theory mainly uses prior information, the data of reliability testing for qualification acceptance, and the posterior information is obtained according to Bayesian estimation formula. Finally, the reliability testing method for subway trains acceptance is established. For the problem that some reliability testing method for subway trains acceptance cannot truly reflect the reliability level of subway trains, this paper uses the fibonacci iteration algorithm to modify the parameters in reliability testing method for production acceptance based on Bayesian theory. The results demonstrate that the fibonacci algorithm can truly reflect the actual train failure rate, and the reliability testing method for subway trains acceptance proposed in this paper can significantly shorten the test time.
Although incremental dynamic analysis (IDA) can be regarded as an accurate tool for evaluating seismic capacity of structures, it is very time intensive. Generating IDA curves requires performing multiple nonlinear ti...
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Although incremental dynamic analysis (IDA) can be regarded as an accurate tool for evaluating seismic capacity of structures, it is very time intensive. Generating IDA curves requires performing multiple nonlinear time-history analyses (NTHA) for given earthquake records. In this paper, a new algorithm based on fibonacci sequence is developed for finding the maximum intensity measure (IM) under which the structure's dynamic response is numerically stable. It is shown that, by performing a very limited number of evaluations, the method can locate this point with the desired accuracy even if the IDA curve is not unimodal. Once the maximum IM is found, the whole IDA curve can be obtained by performing a few more NTHAs. Since the proposed method can be regarded as an optimal approach for establishing the IDA curves, it can be efficiently used in optimization problems in which objective functions or the constraints are related to IDA analyses.
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