5 resultados para Hiding-proofness

em Chinese Academy of Sciences Institutional Repositories Grid Portal


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Watermarking aims to hide particular information into some carrier but does not change the visual cognition of the carrier itself. Local features are good candidates to address the watermark synchronization error caused by geometric distortions and have attracted great attention for content-based image watermarking. This paper presents a novel feature point-based image watermarking scheme against geometric distortions. Scale invariant feature transform (SIFT) is first adopted to extract feature points and to generate a disk for each feature point that is invariant to translation and scaling. For each disk, orientation alignment is then performed to achieve rotation invariance. Finally, watermark is embedded in middle-frequency discrete Fourier transform (DFT) coefficients of each disk to improve the robustness against common image processing operations. Extensive experimental results and comparisons with some representative image watermarking methods confirm the excellent performance of the proposed method in robustness against various geometric distortions as well as common image processing operations.

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A set of tools of clinical psychological intervention for cancer patients had been composed for the first time in the form of a manual with three tapes and some pictures. The cancer patients during chemotherapy were treated by psychological intervention via the tools in group and individual therapy. QLQ-C30, POMS-SF and DWI-CI were first recommended and used as indicators for measuring the results of QoL, emotion and coping method in cancer patients in Chinese mainland. NK cell activity and IgG、IgM, IgA were used to measure the immune function. 120 cancer chemotherapy patients were randomly assigned to one of four conditions formed by a 2 (pre-chemotherapy and post-chemotherapy) *2 (experimental and control group) factorial design. The effect of psychological intervention on quality of life and immune function for cancer patients was investigated as well as the mediate role of coping method and personality and their factors. The efficiency of the tools was verified. The major conclusive results drawn out from the study were: 1. After treated by psychological intervention for three months, the status of quality of life and the symptoms of the patients during the chemotherapy was improved accompanying with the increase of immune parameters, especially the NK cell activity. The influential way of the factors, which effected on the effect of psychological intervention on the quality of life, immune parameters and coping methods, was synthetic. There was obvious mutual effects among the factors. 2. The patients of experimental group used more the active behavior, more the active cognition and less the avoidance coping method than those in control group. 3. The results of measurement showed that the personality of the caner patients was of obvious concealing and hiding. 4. Quality of Life Questionnaire-Core 30(QLQ-C30) was suitable for the cancer patients with great efficiency in Chinese mainland although the scale of SF needed to be revised in the light of Chinese culture.