• Korean Journal of Cognitive Science
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• v.23 no.4
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• pp.517-551
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• 2012

We are imitating animals. True imitation can be defined as a learning to do an act from seeing it done by others. We have been building culture by imitating others' skills and knowledge with high fidelity. In this regard, it is important to ask how the faculty of imitation has evolved and how imitation behaviors develop ontogenetically. It is also interesting to see whether nonhuman animals can imitate truly or not and how different imitation learning is among human and non-human animals. In this paper, first I review empirical data from imitation studies with human and nonhuman animals. Comparing different species, I highlight their different levels of copying fidelity and explain the reason why they are showing the difference. Then I review recent studies on neurobiological mechanisms underlying imitation. The initial neurobiological studies on imitation in humans suggested a core imitation circuitry composed of mirror neuron system [inferior parietal lobule(IPL) and inferior frontal gyrus(IFG)] and the posterior part of the superior temporal sulcus(pSTS). More recent studies on the neurobiology of imitation, however, has gone beyond the studies on the core mechanisms. Finally, I try to find out implications of psychology and biology of imitation for cultural evolution. I argue for a memetic approach to cultural evolution, along the lines with a recent study on measuring memes by mirror neurons system.

• Journal of Broadcast Engineering
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• v.21 no.2
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• pp.149-156
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• 2016

We proposed a blind watermarking scheme using singular vectors based on Discrete Wavelet Transform (DWT) and Redundant Discrete Wavelet Transform (RDWT) combined with Singular Value Decomposition (SVD) for copyright protection application. We replaced the 1st left and right singular vectors decomposed from cover image with the corresponding ones from watermark image to overcome the false-positive problem in current watermark systems using SVD. The proposed scheme realized the watermarking system without a false positive problem, and shows high fidelity and robustness.

• Journal of Korean Society for Geospatial Information Science
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• v.18 no.3
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• pp.57-65
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• 2010

This research aimed to prevent illegal distribution and reproduction of digital cadastral map information using digital watermarking. To this end, a digital watermarking was developed in consideration of the properties of cadastral maps and based on watermarking methods, after which its performance was evaluated. A watermark key and a one-way function was used to compensate for the algorithm and, therefore, watermarking security, based on the existing research results. In these ways, the present method meets the requirements for fidelity, robustness, false positive rate and the maintenance of consistent topology. The advanced techniques suggested in this paper were devised so as to be suitable for vector data such as GIS and navigation data as well as cadastral maps. Moreover, if the existing methodology is further improved, it could be expected to be used even more widely.

• Spatial Information Research
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• v.21 no.3
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• pp.31-43
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• 2013

Although the vector map data possesses much higher values than other types of multimedia, the data copyright and the protection against illegal duplication are still far away from the attention. This paper proposes a novel watermarking technique which is both robust to diverse attacks and optimized to a vector map structure. Six approaches are proposed for the design of the watermarking algorithm: point-based approach, building a minimum perimeter triangle, watermark embedding in the length ratio, referencing to the pixel position of the watermark image, grouping, and using the one-way function. Our method preserves the characteristics of watermarking such as embedding effectiveness, fidelity, and false positive rate, while maintaining robustness to all types of attack except a noise attack. Furthermore, our method is a blind scheme in which robustness is independent of the map data. Finally, our method provides a solution to the challenging issue of degraded robustness under severe simplification attacks.

• Korean Journal of Animal Reproduction
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• v.25 no.3
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• pp.219-225
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• 2001

To establish rabbit Embryonic Stem (ES) cells, rabbit one-cell embryos were collected and cultured in vitro to blastocysts. Blastocysts were co-cultured with mouse embryonic fibroblasts (MEF), rabbit embryonic fibroblasts (REF) or 570 cells expressing LIF (SNL). Although rabbit ES cells were isolated with low efficiencies, total 8 ES cell lines were kept in vitro with normal colony shape. The MEF was the best feeder for rabbit ES cell isolation in regard to growth rate and undifferentiated morphology. The doubling time of rabbit ES cells in MEF was about 84 hours and the undifferentiated morphology was maintained following passing and freezing processes. These rabbit ES cells were differentiated into embryoid body following the culture in the uncoated dishes, indicating that they were undifferentiated stem cells.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.9 no.4
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• pp.59-68
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• 2009

This paper addresses a hybrid multi-focus image fusion scheme using the recent curvelet transform constructions. Hybridization is obtained by combining the MS fusion rule with a novel "copy" method. The proposed scheme use MS rule to fuse the m most significant terms in spectrum of an image at each decomposition level. The scheme is dubbed in this work as m-term fusion in adherence to its use of the MSC (most significant coefficients) in the transform set at any given scale, orientation, and translation. We applied the edge-sensitive objective quality measure proposed by Xydeas and Petrovic to evaluate the method. Experimental results show that the proposed scheme is a potential alternative to the redundant, shift-invariant Dual-Tree Complex Wavelet transforms. In particular, it was confirmed that a 50% m-term fusion produces outputs with no visible quality degradation.