30 results about "Chaos model" patented technology

The invention discloses a pipeline weak leakage detecting device and a detecting method based on a fuzzy hyperbolic chaos model and belongs to the technical field of pipeline detection. Two-stage detection is used, the first-stage detection is abnormal signal detection based on a neural network to mark abnormal signals, and the second-stage detection detects the abnormal signals marked by the first-state detection. By the two-stage detection, the first-stage primary detection is fast, the second-stage detection detects the abnormal signals marked by the first-state detection, and leakage detection capability is increased. The two-stage detection can be implemented on a FPGA (field programmable gate array) hardware platform, and overall system response speed is increased. By the double coupling time-varying delay fuzzy hyperbolic chaos model of the second-stage detection, initial value sensitivity and noise immunity of the chaos system is utilized to increase identification capability of weak leakage signals submerged in noise so as to highlight chaos phenomenon, system requirements for signal to noise ratio is lowered, and weak leakage detection is achieved.

The present invention relates to a document integrity authentication method based on an interleaving watermark and a biological feature, a chaos model is adopted to generate an authentication code, and the biological information of a deliverer is generated to a biological feature code streaming after being extracted through the feature. The authentication code and the biological feature code streaming are returned to the deliverer after a plurality of interleaving treatments under the control of a third party, and then the deliverer inserts the interleaving information in the document. When being authenticated, on the one hand, the extracted authentication code and a generated reference sequence are compared, the integrity of the document content is determined, and a tampered area is positioned; on the other hand, the extracted biological feature is identified, the identity of the deliverer is determined, and a disavowal behavior is prevented. The present invention can authenticate the integrality of the document, and can detect and position a tampered location. The different requirements of users to the precision are supported, and the positioning precision is adjustable and controllable. An authentication result is given by error, and the tampered location can be directly and visually reflected. The identity of the deliver can be determined, and the disavowal behavior is prevented.

The invention discloses an underwater acoustic communication information source channel joint decoding method, which comprises the following steps: acquiring information data sent by an encoding end,demodulating the information data, and determining a receiving symbol sequence and an information source contribution degree, the information source contribution degree being a ratio of redundancy ofa sending information source sequence to a redundancy mean value; generating a joint decoding tree by utilizing a recursive chaos model according to the encoding parameters of the encoding end, and calculating a part of encoding symbol sequences corresponding to each branch in the decoding tree and a part of information sequences corresponding to decoding paths in the decoding tree layer by layer;calculating a branch metric value of eac information sequence of the decoding tree by adopting an information source channel joint maximum posteriori probability criterion and combining noise energy,information source prior information, the information source contribution degree and the receiving symbol sequence; and calculating a path metric sum value corresponding to each branch in the decoding tree, and selecting the branch corresponding to the maximum path metric sum value to obtain a decoding information sequence. According to the method, the correlation between signal source symbols isfully utilized, channel decoding is corrected, and the decoding performance of underwater acoustic communication is improved.

The invention relates to an image encryption method based on a three-dimensional composite scrambling model and chaos, which belongs to the field of information encryption. The current network transmission security problem is becoming more and more serious. In order to protect the network interactive image content, the present invention proposes an image encryption method based on a three-dimensional composite scrambling model and chaos. Combining technologies such as bit-plane decomposition, piecewise linear chaotic mapping and two-dimensional Zigzag transformation, a three-dimensional compound scrambling model is established on the basis of defining block internal scrambling and block scrambling. The model is used to scramble the pixels of the original image, and then the Chenchao system and XOR operation are used to diffuse the scrambled image to obtain an encrypted image. Experiments show that the algorithm has good encryption effect, high security and high efficiency.