To improve the visual quality and embedding rate of existing reversible image watermarking algorithms, a reversible image watermarking algorithm based on quadratic difference expansion is proposed. First, the pixel points with grayscale values 0 and 255 in the original image are removed, and then, the half-scrambled watermark information is embedded into the original image using linear difference expansion. Finally, the remaining half of the watermark information is embedded into the previously generated watermarked image by the quadratic difference expansion, meanwhile the removed pixel points with grayscale values 0 and 255 in the image are merged, and the final watermarked image is generated accordingly. The experimental results show that the algorithm has both a high embedding rate and a high visual quality, which can completely recover the original image. Compared with other difference expansion watermarking algorithms, it has certain advantages without having to consider the smoothness of the embedded image region.
Question Answering system (QA), is a kind of new information retrieval system which can be queried with natural language and return knowledge directly.By improving the traditional Chinese sentence similarity model, this paper proposes a Chinese sentence similarity calculation method based on keywords weight.Its key question is that questions asked by user and questions in the Frequently Asked Question (FAQ) carry on similarity calculation, discover the closest question in the FAQ and return the question answer stored in advance. It can also automatically update and maintain FAQ.The experiment indicates that precision of question match can be improved compared with traditional sentence similarity model.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.