Neural stem cell is presently the research hotspot in neuroscience. Recent progress indicates that epigenetic modulation is closely related to the self-renewal and differentiation of neural stem cell. Epigenetics refe...Neural stem cell is presently the research hotspot in neuroscience. Recent progress indicates that epigenetic modulation is closely related to the self-renewal and differentiation of neural stem cell. Epigenetics refer to the study of mitotical/meiotical heritage changes in gene function that cannot be explained by changes in the DNA sequence. Major epigenetic mechanisms include DNA methylation, histone modification, chromatin remodeling, genomic imprinting, and non-coding RNA. In this review, we focus on the new insights into the epigenetic mechanism for neural stem cells fate.展开更多
All watermarks are shared into shadow images using VCS(Visual Cryptography Scheme). Only one specific shadow (as a new watermark) is embedded into the host signal and the other ones are distributed to every user in ea...All watermarks are shared into shadow images using VCS(Visual Cryptography Scheme). Only one specific shadow (as a new watermark) is embedded into the host signal and the other ones are distributed to every user in each group as a key. In the watermarking extraction procedure, users in different group can obtain different watermark by combining their shadows with the extracted one from the watermarked signal. Analysis and experimental results show that the new watermarking method is novel, secure and robust.展开更多
Watermarking is an effective approach to the copyright protection of digital media such as audio, image, and video. By inspiration from cryptography and considering the immensity of the set of all possible wavelets, i...Watermarking is an effective approach to the copyright protection of digital media such as audio, image, and video. By inspiration from cryptography and considering the immensity of the set of all possible wavelets, it is presented that in wavelet domain watermarking, the associated wavelet can be considered as the private key for encrypting the watermark so as to enhance the security of the embedded mark. This idea is partly supported by the fact that from computational complexity viewpoint, it is very time-consuming to search over the immense set of all candidate wavelets for the right one if no a priori knowledge is known about it. To verify our proposal, the standard image 'Lena' is first watermarked in a specific wavelet domain, the watermark recovery experiments are then conducted in the wavelet domain for a set of wavelets with the one used for mark embedded in it,separately. It follows from the experimental results that the mark can be recovered only in the right wavelet domain, which justifies the suggestion.展开更多
A multiple watermarking algorithm is presented according to the multiple accessing technique of the code division multiple access （CDMA） system. Multiple watermarks are embedded into digital images in the wavelet tr...A multiple watermarking algorithm is presented according to the multiple accessing technique of the code division multiple access （CDMA） system. Multiple watermarks are embedded into digital images in the wavelet transform domain. Each of the watermarks is embedded and extracted independently without impacts to each other. Multiple watermarks are convolution encoded and block interleaved, and the orthogonal Gold sequences are used to spread spectrum of the copyright messages. CDMA encoded water-mark messages are embedded into the wavelet sub-bands excluding the wavelet HH1 sub-bands. The embedment amplitude is decided by Watson＇ s perceptual model of wavelet transform domain, and the embedmeut position in the selected wavelet sub-bands is decided randomly by a pseudo-random noise （PN） sequence. As a blind watermm＇king algorithm, watermarks are extracted without original image. The watermarking capacity of proposed algorithm is also discussed. When two watermarks are embedded in an image at the same time, the capacity is larger than the capacity when a single watermark is embedded, and is smaller than the sum of the capacity of two separately embedded watermarks. Experimental results show that the proposed algorithm improves the detection bits error rate （BER） observably, and the multiple watermarks have a preferable robustness and invisibility.展开更多
Transliteration editors are essential for keying-in Indian language scripts into the computer using QWERTY keyboard. Applications of transliteration editors in the context of Universal Digital Library (UDL) include en...Transliteration editors are essential for keying-in Indian language scripts into the computer using QWERTY keyboard. Applications of transliteration editors in the context of Universal Digital Library (UDL) include entry of meta-data and diction- aries for Indian languages. In this paper we propose a simple approach for building transliteration editors for Indian languages using Unicode and by taking advantage of its rendering engine. We demonstrate the usefulness of the Unicode based approach to build transliteration editors for Indian languages, and report its advantages needing little maintenance and few entries in the mapping table, and ease of adding new features such as adding letters, to the transliteration scheme. We demonstrate the trans- literation editor for 9 Indian languages and also explain how this approach can be adapted for Arabic scripts.展开更多
A blind and readable image watermarking scheme using wavelet tree quantization is proposed. In order to increase the algorithm robustness and ensure the watermark integrity,error correction coding techniques are used ...A blind and readable image watermarking scheme using wavelet tree quantization is proposed. In order to increase the algorithm robustness and ensure the watermark integrity,error correction coding techniques are used to encode the embedded watermark. In the watermark embedding process, the wavelet coefficients of the host image are grouped into wavelet trees and each watermark bit is embedded by using two trees. The trees are so quantized that they exhibit a large enough statistical difference, which will later be used for watermark extraction. The experimental results show that the proposed algorithm is effective and robust to common image processing operations and some geometric operations such as JPEG compression, JPEG2000 compression, filtering, Gaussian noise attack, and row-column removal. It is demonstrated that the proposed technique is practical.展开更多
This paper proposes a video watermarking technology to hide copyright information by a slight modification of the motion vector in MPEG-2 video bitstream. In this method, the watermark is embedded in the motion residu...This paper proposes a video watermarking technology to hide copyright information by a slight modification of the motion vector in MPEG-2 video bitstream. In this method, the watermark is embedded in the motion residual of the large value motion vector, then the motion residual is regularized into a modified bitstream, from which the watermark information can be retrieved easily and exactly. From the experimental results, this technology has the advantage of little influence on the MPEG decoding speed, degrading the perceptive effect little, and the capability to embed watermark in a short video sequence, and can be used to watermark directly on the compressed and uncompressed video sequence.展开更多
文摘Neural stem cell is presently the research hotspot in neuroscience. Recent progress indicates that epigenetic modulation is closely related to the self-renewal and differentiation of neural stem cell. Epigenetics refer to the study of mitotical/meiotical heritage changes in gene function that cannot be explained by changes in the DNA sequence. Major epigenetic mechanisms include DNA methylation, histone modification, chromatin remodeling, genomic imprinting, and non-coding RNA. In this review, we focus on the new insights into the epigenetic mechanism for neural stem cells fate.
基金Supported by the National Natural Science Foundation of China (No.90204017, 60373059)National 973 Project (G1999035805) ISN Open Foundation
文摘All watermarks are shared into shadow images using VCS(Visual Cryptography Scheme). Only one specific shadow (as a new watermark) is embedded into the host signal and the other ones are distributed to every user in each group as a key. In the watermarking extraction procedure, users in different group can obtain different watermark by combining their shadows with the extracted one from the watermarked signal. Analysis and experimental results show that the new watermarking method is novel, secure and robust.
基金Funded by the visit scholar Foundation of the Electrooptical Technique & System key Lab of Chinese Ministry of Education in Chongqing.
文摘Watermarking is an effective approach to the copyright protection of digital media such as audio, image, and video. By inspiration from cryptography and considering the immensity of the set of all possible wavelets, it is presented that in wavelet domain watermarking, the associated wavelet can be considered as the private key for encrypting the watermark so as to enhance the security of the embedded mark. This idea is partly supported by the fact that from computational complexity viewpoint, it is very time-consuming to search over the immense set of all candidate wavelets for the right one if no a priori knowledge is known about it. To verify our proposal, the standard image 'Lena' is first watermarked in a specific wavelet domain, the watermark recovery experiments are then conducted in the wavelet domain for a set of wavelets with the one used for mark embedded in it,separately. It follows from the experimental results that the mark can be recovered only in the right wavelet domain, which justifies the suggestion.
基金the National High Technology Research and Development Programme of China(No 2006AA01Z407,No.2007AA01Z478)the Postdoctoral Science Foundation of China(No.20070420707)
文摘A multiple watermarking algorithm is presented according to the multiple accessing technique of the code division multiple access （CDMA） system. Multiple watermarks are embedded into digital images in the wavelet transform domain. Each of the watermarks is embedded and extracted independently without impacts to each other. Multiple watermarks are convolution encoded and block interleaved, and the orthogonal Gold sequences are used to spread spectrum of the copyright messages. CDMA encoded water-mark messages are embedded into the wavelet sub-bands excluding the wavelet HH1 sub-bands. The embedment amplitude is decided by Watson＇ s perceptual model of wavelet transform domain, and the embedmeut position in the selected wavelet sub-bands is decided randomly by a pseudo-random noise （PN） sequence. As a blind watermm＇king algorithm, watermarks are extracted without original image. The watermarking capacity of proposed algorithm is also discussed. When two watermarks are embedded in an image at the same time, the capacity is larger than the capacity when a single watermark is embedded, and is smaller than the sum of the capacity of two separately embedded watermarks. Experimental results show that the proposed algorithm improves the detection bits error rate （BER） observably, and the multiple watermarks have a preferable robustness and invisibility.
文摘Transliteration editors are essential for keying-in Indian language scripts into the computer using QWERTY keyboard. Applications of transliteration editors in the context of Universal Digital Library (UDL) include entry of meta-data and diction- aries for Indian languages. In this paper we propose a simple approach for building transliteration editors for Indian languages using Unicode and by taking advantage of its rendering engine. We demonstrate the usefulness of the Unicode based approach to build transliteration editors for Indian languages, and report its advantages needing little maintenance and few entries in the mapping table, and ease of adding new features such as adding letters, to the transliteration scheme. We demonstrate the trans- literation editor for 9 Indian languages and also explain how this approach can be adapted for Arabic scripts.
文摘A blind and readable image watermarking scheme using wavelet tree quantization is proposed. In order to increase the algorithm robustness and ensure the watermark integrity,error correction coding techniques are used to encode the embedded watermark. In the watermark embedding process, the wavelet coefficients of the host image are grouped into wavelet trees and each watermark bit is embedded by using two trees. The trees are so quantized that they exhibit a large enough statistical difference, which will later be used for watermark extraction. The experimental results show that the proposed algorithm is effective and robust to common image processing operations and some geometric operations such as JPEG compression, JPEG2000 compression, filtering, Gaussian noise attack, and row-column removal. It is demonstrated that the proposed technique is practical.
文摘This paper proposes a video watermarking technology to hide copyright information by a slight modification of the motion vector in MPEG-2 video bitstream. In this method, the watermark is embedded in the motion residual of the large value motion vector, then the motion residual is regularized into a modified bitstream, from which the watermark information can be retrieved easily and exactly. From the experimental results, this technology has the advantage of little influence on the MPEG decoding speed, degrading the perceptive effect little, and the capability to embed watermark in a short video sequence, and can be used to watermark directly on the compressed and uncompressed video sequence.
