A contrast-sensitive reversible visible image watermarking technique

A reversible (also called lossless, distortion-free, or invertible) visible watermarking scheme is proposed to satisfy the applications, in which the visible watermark is expected to combat copyright piracy but can be removed to losslessly recover the original image. We transparently reveal the watermark image by overlapping it on a user-specified region of the host image through adaptively adjusting the pixel values beneath the watermark, depending on the human visual system-based scaling factors. In order to achieve reversibility, a reconstruction/ recovery packet, which is utilized to restore the watermarked area, is reversibly inserted into non-visibly-watermarked region. The packet is established according to the difference image between the original image and its approximate version instead of its visibly watermarked version so as to alleviate its overhead. For the generation of the approximation, we develop a simple prediction technique that makes use of the unaltered neighboring pixels as auxiliary information. The recovery packet is uniquely encoded before hiding so that the original watermark pattern can be reconstructed based on the encoded packet. In this way, the image recovery process is carried out without needing the availability of the watermark. In addition, our method adopts data compression for further reduction in the recovery packet size and improvement in embedding capacity. The experimental results demonstrate the superiority of the proposed scheme compared to the existing methods

2-(3-Bromo-4-ethyl­phen­yl)-2-methyl­propanoic acid

In the title compound, C12H15BrO2, the carboxyl group forms a dihedral angle of 78.4 (3)° with the benzene ring plane. In the crystal, mol­ecules are linked into centrosymmetric dimers by pairs of O—H⋯O hydrogen bonds

New Optimal Weight Combination Model for Forecasting Precipitation

In order to overcome the inaccuracy of the forecast of a single model, a new optimal weight combination model is established to increase accuracies in precipitation forecasting, in which three forecast submodels based on rank set pair analysis (R-SPA) model, radical basis function (RBF) model and autoregressive model (AR) and one weight optimization model based on improved real-code genetic algorithm (IRGA) are introduced. The new model for forecasting precipitation time series is tested using the annual precipitation data of Beijing, China, from 1978 to 2008. Results indicate the optimal weights were obtained by using genetic algorithm in the new optimal weight combination model. Compared with the results of R-SPA, RBF, and AR models, the new model can improve the forecast accuracy of precipitation in terms of the error sum of squares. The amount of improved precision is 22.6%, 47.4%, 40.6%, respectively. This new forecast method is an extension to the combination prediction method

Topological surface electronic states in candidate nodal-line semimetal CaAgAs

We investigate systematically the bulk and surface electronic structure of the candidate nodal-line semimetal CaAgAs by angle resolved photoemission spectroscopy and density functional calculations. We observed a metallic, linear, non-$k_z$-dispersive surface band that coincides with the high-binding-energy part of the theoretical topological surface state, proving the topological nontriviality of the system. An overall downshift of the experimental Fermi level points to a rigid-band-like $p$-doping of the samples, due possibly to Ag vacancies in the as-grown crystals.Comment: 6 pages, 5 figure

Acupuncture Deqi Intensity and Propagated Sensation along Channels May, Respectively, Differ due to Different Body Positions of Subjects

Acupuncture as an essential component of complementary and alternative medicine is gradually recognized and accepted by the mainstream of contemporary medicine. For obtaining preferable clinical effectiveness, Deqi is commonly regarded as efficacy predictor and parameter which is necessary to be achieved. Influential factors for acupuncture efficacy, like Deqi sensation as well as propagated sensation along channels (PSCs), enjoyed a long history in acupuncture basic research. Concerning this study, taking into account different positions on acupuncture Deqi sensation and PSCs, we would like to attest whether different body positions for subjects during needling procedure yield differed acupuncture Deqi sensation, particularly in terms of intensity, and PSCs. Methods. We used self-controlled method and selected 30 healthy subjects to perform needle insertion at Futu point (ST32) bilaterally. Then they were instructed to record the value of intensity of acupuncture sensation and the length and width of PSCs after removing the needle. Results. In regard to intensity of Deqi, kneeling seat position is stronger than supine position, accounting for 90% of the total number of subjects. In length of PSCs, kneeling seat position is greater than supine position, accounting for 56.7%. In width of PSCs, kneeling seat position is greater than supine position, accounting for 66.7%. Conclusion. Our findings show that needle inserting at Futu point (ST32) in kneeling seat position achieve better needle sensation and provide reference for clinical

4-(2-Chloro­anilino)-3-phenyl­furan-2(5H)-one

The title compound, C16H12ClNO2, featuring a furan-2(5H)-one (γ-butyrolactone) core, contains two mol­ecules (A and B) in the asymmetric unit, with different dihedral angles between the central ring and the pendant phenyl and chloro­benzene rings [43.33 (8) and 20.16 (8)°, respectively, for A, and 47.79 (8) and 13.87 (8)°, respectively, for B]. In the crystal, the A mol­ecules are linked into [001] chains by single C—H⋯O inter­actions. The B mol­ecules also form [001] chains, but their relative orientations in the chains are quite different to those of the A mol­ecules so that adjacent B mol­ecules are linked by two C—H⋯O hydrogen bonds. Finally, C—H⋯O inter­actions and aromatic π–π stacking contacts [centroid–centroid separations = 3.754 (1) and 3.817 (1) Å] link the chains into a two-dimensional array parallel to (010)

Waterbird Composition and Changes With Wetland Park Construction at Lake Dianchi, Yunnan–Guizhou Plateau

Establishing effectively protected and managed ecosystems with high biodiversity is the broad aim of the Aichi initiative. Assessing the biodiversity of a specific ecosystem is the first step in estimating its conservation value. Most lakes on the Yunnan–Guizhou Plateau are formed by mountain faulting and are surrounded by human settlements. Lake ecosystems are fragile and frequently disturbed by pollution, agricultural activities, and tourism. The current lakeside wetland parks are intended to abate pollution and promote tourism. However, the composition of the monthly and yearly waterbird population and the impacts of the parks on waterbirds are unclear. Using direct observation and spot map census methods, we conducted 104 field surveys across 4 consecutive years at Lake Dianchi to fill the gaps in current knowledge. The results showed that Dianchi could provide habitats for more than 60,000 individual birds of 105 species, including residents, summer visitors, migrants, and winter visitors. The current oxidation ponds in wetland parks, created for water purification and tourism, were not suitable for most shorebirds. Consequently, we suggest that plans for the construction of artificial wetlands or wetland parks in this region should consider the habitat requirements of different waterbirds in different seasons. Particular attention should be given to protecting the marshlands and mudflats that wading birds require. We also suggest that increased waterbird monitoring in different seasons across different years is needed around Lake Dianchi and other wetlands on the Yunnan–Guizhou Plateau for effective conservation