Nanjing Normal University

Nanjing University

Nanjing Institute of Environmental Sciences, Mee

The Third Surveying and Mapping Institute of Hunan Province

Changqing Zhu

Qianwen Zhou

Na Ren

Heyan Wang

Yuchen Hu

Aimin Li

Fuqiang Liu

Wei Zhao

Ni Ni

Na Wang

Xinyan Guo

Chen Ling

Li Song

Yanhong Zhang

Xuchao Lv

Yang Song

Renyong Shi

Xingxiang Jiang

Tan Chen

Yujing Liu

Luanyun Hu

Xi Liu

Hua Sun

Sheng Chen

A zero-watermarking method and device for BIM data, and a medium are provided, which relate to the field of watermarking information security technologies. Aiming at existing zero-watermarking method for the BIM data cannot resist primitive attacks, vertical stability of a model is used to construct a mapping relationship between primitive clusters and watermarking bits, calculate norms of primitives in each primitive cluster of the primitive clusters, take positivity and negativity of norm skewness measurement of the primitives as eigenvalues to construct a binary sequence, and performs an XOR process on the binary sequence and an original watermarking sequence to construct the zero-watermarking for the BIM data. Experimental results indicate that the zero-watermarking method has uniqueness, robustness and security.

Zero-watermarking method and device for BIM data, and medium

The present disclosure relates to the technical field of waste water treatment, and provides a device and a method for controlling diffusion of MPs (Microplastics) carried with ARGs (Antibiotic Resistance Genes) in a waste water treatment system. The device includes a water collection tank arranged on a mounting rack, a collection assembly arranged inside the water collection tank and used for collecting MPs carried with ARGs in waste water, and a treatment assembly arranged inside the water collection tank and used for removing the collected MPs carried with ARGs in waste water. According to the method, sorting treatment for the MPs carried with ARGs in waste water is realized effectively with an air flotation principle and an electric separation principle. The device is simple in integral structure, and has the advantage of convenience in mounting.

Device and method for controlling diffusion of MPs carried with ARGs in waste water treatment system

A dual watermarking method for trajectory data based on robust watermarking and fragile watermarking uses an encryption algorithm to construct robust watermark information, and then a farthest pair of feature points in a minimum convex hull of is set as constant points. Further quantization index modulation technology is used to embed robust watermark information into angles constructed from feature points and constant points. Finally, the angles and distance ratios constructed by trajectory points and constant points are used to group trajectory points. Within each group, spatiotemporal attributes of the trajectory points are taken as fragile watermark bits to be embedded in the distance ratios constructed by the trajectory points. A process of watermark detection is consistent with the embedding of watermark information. Watermarks embedded in the trajectory data based on the dual watermarking method have high robustness against translation, rotation, and scaling attacks.

Dual watermarking method for trajectory data based on robust watermarking and fragile watermarking

A watermarking method for a high-definition map based on invisible characters includes: firstly, establishing mapping relations between invisible characters and bit characters, a space character, and decimal digits; and combining watermark characters with corresponding positions thereof, adding Hamming code into a watermark character sequence, and converting the watermark character sequence into invisible characters to construct a composite watermark character sequence. Before watermark detection, a sequence of elements in map data is scrambled according to logistic chaotic mapping, and then the composite watermark character sequence is embedded according to the scrambled sequence. During watermark detection, the data are preprocessed, a sequence during watermark embedding is obtained, and then watermark information is extracted, errors are corrected, and an error correcting code is removed after correction to obtain final watermark information. According to the watermarking method, watermark embedding and watermark detection can be realized not changing data availability and high-accuracy characteristic.

Watermarking method for high-definition map based on invisible characters

A generation method of zero watermarking for trajectory data, a detection method of zero watermarking for trajectory data, a generation device of zero watermarking for trajectory data, a detection device of zero watermarking for trajectory data, and a storage medium are provided. The generation method divides a trajectory based on a coordinate system constructed by trajectory feature points of trajectory data into blocks, and then the moment invariants of trajectory in each block are used to construct a watermark sequence, which can achieve copyright protection without modifying the trajectory data. In addition, since the generation method uses moment invariants which can represent overall features of the trajectory to construct the watermark sequence, the generation method has strong stability in the face of common attacks and can resist almost all common types of attacks.

Generation method, detection method, generation device, and detection device of zero watermarking for trajectory data, and storage medium

A polyvinylidene fluoride (PVDF) casting membrane solution is shaped as a flat sheet membrane by thermally induced phase separation (TIPS), the PVDF membrane is defluorinated with an alkaline potassium permanganate solution, and then the carbon chain is extended with glycidyl methacrylate (GMA) as the graft monomer, and finally the nucleophilic substitution is carried out between melamine and GMA to produce a chelating microfiltration membrane for capturing and enriching heavy metals with high flux and high capacity.

Preparation, regeneration and application of a chelating microfiltration membrane

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Nanjing, China

Changqing Zhu