709 research outputs found
Content-Aware Quantization Index Modulation:Leveraging Data Statistics for Enhanced Image Watermarking
Image watermarking techniques have continuously evolved to address new
challenges and incorporate advanced features. The advent of data-driven
approaches has enabled the processing and analysis of large volumes of data,
extracting valuable insights and patterns. In this paper, we propose two
content-aware quantization index modulation (QIM) algorithms: Content-Aware QIM
(CA-QIM) and Content-Aware Minimum Distortion QIM (CAMD-QIM). These algorithms
aim to improve the embedding distortion of QIM-based watermarking schemes by
considering the statistics of the cover signal vectors and messages. CA-QIM
introduces a canonical labeling approach, where the closest coset to each cover
vector is determined during the embedding process. An adjacency matrix is
constructed to capture the relationships between the cover vectors and
messages. CAMD-QIM extends the concept of minimum distortion (MD) principle to
content-aware QIM. Instead of quantizing the carriers to lattice points,
CAMD-QIM quantizes them to close points in the correct decoding region.
Canonical labeling is also employed in CAMD-QIM to enhance its performance.
Simulation results demonstrate the effectiveness of CA-QIM and CAMD-QIM in
reducing embedding distortion compared to traditional QIM. The combination of
canonical labeling and the minimum distortion principle proves to be powerful,
minimizing the need for changes to most cover vectors/carriers. These
content-aware QIM algorithms provide improved performance and robustness for
watermarking applications.Comment: 12 pages, 10 figure
(2,9-Diethoxy-1,10-phenanthroline-κ2 N,N′)bis(thiocyanato-κN)cobalt(II)
In the title complex, [Co(NCS)2(C16H16N2O2)], the CoII ion is coordinated by two N atoms from one 2,9-diethoxy-1,10-phenanthroline ligand and two N atoms from two different thiocyanate ligands in a distorted tetrahedral environment. The Co—N bonds involving the thiocyanate ligands are significantly shorter than the other two Co—N bonds. The atoms of one of the ethoxy groups are essentially coplanar with the phenanthroline ring [N=C—O—C = 178.8 (4)°], while the other ethoxy group is slightly twisted from the phenanthroline ring plane [N=C—O—C = 167.2 (4)°]. In the crystal structure, there is a weak π–π stacking interaction between two symmetry-related phenanthroline rings with a centroid–centroid distance of 3.706 (4) Å
Fast Beam Training for FDD Multi-User Massive MIMO Systems With Finite Phase Shifter Resolution
catena-Poly[[(2,9-diethoxy-1,10-phenanthroline-κ2 N,N′)cadmium(II)]-di-μ-dicyanamido-κ4 N 1:N 5]
In the title polymer, [Cd(C2N3)2(C16H16N2O2)]n, the CdII ion is coordinated by two N atoms from one 2,9-diethoxy-1,10-phenanthroline molecule and four N atoms from four symmetry-related dicyanamide ions in a distorted octahedral geometry. In the 2,9-diethoxy-1,10-phenanthroline ligand, the O and C atoms of the ethoxy groups are located almost in the plane defined by the phenanthroline ring system. Two dicyanamide ions bridge two CdII ions, which are located on a twofold axis, forming a one-dimensional zigzag chain along the [001] direction. The 2,9-diethoxy-1,10-phenanthroline molecules act as bidentate terminal ligands. There are π–π interactions between polymeric chains, characterized by a centroid–centroid distance of 3.7624 (2) Å between the phenanthroline rings of two neighbouring chains
The prognostic value of deep earlobe creases in patients with acute ischemic stroke
Background and purposeData on earlobe crease (ELC) among patients with acute ischemic stroke (AIS) are limited. Here, we determined the frequency and characteristics of ELC and the prognostic effect of ELC among AIS patients.MethodsA total of 936 patients with acute AIS were enrolled during the period between December 2018 and December 2019. The patients were divided into those without and with ELC, unilateral and bilateral ELC, and shallow and deep ELC, according to the photographs taken of the bilateral ears. Logistic regression models were used to estimate the effect of ELC, bilateral ELC, and deep ELC on poor functional outcomes at 90 days (a modified Rankin Scale score ≥2) in AIS patients.ResultsAmong the 936 AIS patients, there were 746 (79.7%) patients with ELC. Among patients with ELC, there were 156 (20.9%) patients with unilateral ELC and 590 (79.1%) with bilateral ELC and 476 (63.8%) patients with shallow ELC and 270 (36.2%) with deep ELC. After adjusting for age, sex, baseline NIHSS score, and other potential covariates, patients with deep ELC were associated with a 1.87-fold [odds ratio (OR) 1.87; 95% confidence interval (CI), 1.13–3.09] and 1.63-fold (OR 1.63; 95%CI, 1.14–2.34) increase in the risk of poor functional outcome at 90 days in comparison with those without ELC or shallow ELC.ConclusionELC was a common phenomenon, and eight out of ten AIS patients had ELC. Most patients had bilateral ELC, and more than one-third had deep ELC. Deep ELC was independently associated with an increased risk of poor functional outcome at 90 days
A simulation study on the measurement of D0-D0bar mixing parameter y at BES-III
We established a method on measuring the \dzdzb mixing parameter for
BESIII experiment at the BEPCII collider. In this method, the doubly
tagged events, with one decays to
CP-eigenstates and the other decays semileptonically, are used to
reconstruct the signals. Since this analysis requires good separation,
a likelihood approach, which combines the , time of flight and the
electromagnetic shower detectors information, is used for particle
identification. We estimate the sensitivity of the measurement of to be
0.007 based on a fully simulated MC sample.Comment: 6 pages, 7 figure
Neuronal Modulators from the Coral-Associated Fungi Aspergillus candidus
Three new p-terphenyl derivatives, named 400-O-methyl-prenylterphenyllin B (1) and
phenylcandilide A and B (17 and 18), and three new indole-diterpene alkaloids, asperindoles E–G
(22-24), were isolated together with eighteen known analogues from the fungi Aspergillus candidus associated with the South China Sea gorgonian Junceela fragillis. The structures and absolute configurations of the new compounds were elucidated on the basis of spectroscopic analysis, and DFT/NMR and TDDFT/ECD calculations. In a primary cultured cortical neuronal network, the compounds 6, 9, 14, 17, 18 and 24 modulated spontaneous Ca2+ oscillations and 4-aminopyridine hyperexcited neuronal activity. A preliminary structure–activity relationship was discussed
Community perspectives of flagship species: can conservation motivators mitigate human-wildlife conflict?
Public perception of endangered species is crucial for successful management of community-based conservation and sustainability of national parks. By the method of choice experiment, our study evaluated conservation preferences and willingness to donate money for flagship and non-flagship species using a choice experiment with 409 residents living near the Lanstang river source of Sanjiangyuan National Park, China. We found that flagship species such as the Snow leopard (Pristine plateau) and White-lipped deer (Przewalskium albirostris) generated more conservation funds than non-flagship species. However, not all flagship species were accepted. Respondents disliked Tibetan brown bears (Ursus arctos pruinosus) due to direct human-wildlife conflicts such as bodily injury and property damage. Heterogeneity of preference was influenced by household income, religious beliefs, ethnicity, culture, and conservation awareness. Results can be used to establish a local community-participative framework by combining conservation motivations that alleviate human-wildlife conflict
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