• KSII Transactions on Internet and Information Systems (TIIS)
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• v.7 no.6
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• pp.1492-1511
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• 2013

A novel, chaotic map that is based on concatenated torus automorphisms is proposed in this paper. As we know, cat map, which is based on torus automorphism, is highly chaotic and is often used to encrypt information. But cat map is periodic, which decreases the security of the cryptosystem. In this paper, we propose a novel chaotic map that concatenates several torus automorphisms. The concatenated mechanism provides stronger chaos and larger key space for the cryptosystem. It is proven that the period of the concatenated torus automorphisms is the total sum of each one's period. By this means, the period of the novel automorphism is increased extremely. Based on the novel, concatenated torus automorphisms, two application schemes in image encryption are proposed, i.e., 2D and 3D concatenated chaotic maps. In these schemes, both the scrambling matrices and the iteration numbers act as secret keys. Security analysis shows that the proposed, concatenated, chaotic maps have strong chaos and they are very sensitive to the secret keys. By means of concatenating several torus automorphisms, the key space of the proposed cryptosystem can be expanded to $2^{135}$. The diffusion function in the proposed scheme changes the gray values of the transferred pixels, which makes the periodicity of the concatenated torus automorphisms disappeared. Therefore, the proposed cryptosystem has high security and they can resist the brute-force attacks and the differential attacks efficiently. The diffusing speed of the proposed scheme is higher, and the computational complexity is lower, compared with the existing methods.

• The Journal of the Korea institute of electronic communication sciences
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• v.9 no.4
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• pp.469-474
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• 2014

Installed on telephone poles laid scrambling to monitor the status of the communication lines, and cost information can provid eadditional information tools to develop systems to support on-site monitoring. Aerial support for a maintenance monitoring module to apply an embedded system, and information processing applications manufactured. In this study, a comprehensive plan in accordance with the government's aerial maintenance work to prevent accidents spread support for the device to immediately take advantage of big cities and aerial maintenance business, Construction worker accused of bias and aims to improve efficiency of maintenance puts.

• Management & Information Systems Review
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• v.36 no.3
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• pp.1-16
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• 2017

As purchasing power of Chinese consumers has increased and their purchase channels have become more various, Chinese consumers are paying more attention to foreign products and purchasing more of them as well as the domestic goods. With great expectations, many companies in different nations are scrambling into the Chinese market. In this situation, Chinese consumers have a wider range of choices when selecting and purchasing goods, thereby trying to take several factors into account in order to choose the best one in a limited time. This study is about how much country-of-origin image, brand attitude and corporate social responsibility influence Chinese consumers' quality perception and their purchase decisions. The study result shows that country-of-origin image, brand attitude and corporate social responsibility all have a positive effect on perceived quality of the consumers, and among those three, the brand attitude is found to be the most influential factor. It also shows that perceived quality brings a positive effect on purchase intention. Also, in terms of difference in product categories, the influence of corporate social responsibility on perceived quality and the influence of perceived quality on purchase intention are shown greater in dairy products than in PC. This study has academic significance as it has investigated consumer behavior, considering each different factor above. Also it has practical significance since it offers an implication on the marketing strategies of the companies that are planning to advance into the Chinese market in the future.

• Journal of the Institute of Electronics Engineers of Korea SP
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• v.44 no.6
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• pp.16-23
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• 2007

Changeable biometrics has been developed as a solution to problem of enhancing security and privacy. The idea is to transform a biometric signal or feature into a new one for the purposes of enrollment and matching. In this paper, we propose a changeable biometric system that can be applied to appearance based face recognition system. In the first step when using feature extraction, ICA(Independent Component Analysis) coefficient vectors extracted from an input face image are replaced randomly using their mean and variation. The transformed vectors by replacement are scrambled randomly and a new transformed face coefficient vector (transformed template) is generated by combination of the two transformed vectors. When this transformed template is compromised, it is replaced with new random numbers and a new scrambling rule. Because e transformed template is generated by e addition of two vectors, e original ICA coefficients could not be easily recovered from the transformed coefficients.