7 results about "Hamming space" patented technology

The application discloses a cross-modal hash retrieval method and relates to the technical field of cross-modal learning. The method comprises the following steps: 1) a cross-modal feature learning network comprising an image network, a text network and a label network is used to map each triple information to a high-dimensional Hamming space through a feature fusion graph attention classification learning module; 2) a SwinT-S (SwinT Small model) model is used to extract semantic features of images; 3) a graph attention feature fusion attention module is used to perform deep fusion alignment on the obtained image semantic features and text semantic features; 4) a deep text feature extraction network is used to optimize the generation of text hash codes and generate high-quality text hash codes; and 5) a linear layer (Linear) and a Tanh (t) function are used to map text features into hash code lengths required by the application. The application has the beneficial effect of effectively reducing semantic gap problems, fusing different modal features and improving the performance of cross-modal hash retrieval.

The application discloses a remote sensing video hash retrieval method based on key frame fusion and an attention mechanism, and mainly solves the problems that existing methods cannot fully capture the category-level semantics of remote sensing videos and the semantic information is insufficiently utilized. A new video space-time information extraction structure is designed to extract the data representation of three-dimensional video data in two-dimensional space, and an attention mechanism is introduced under the structure of a convolutional neural network to extract the corresponding hash code of the video in the Hamming space. The application not only captures the relative semantic correlation of hash codes in different modes, learns the relative semantic correlation of deep features, but also enhances the category-level semantics of hash codes and reduces the quantization error between class hash codes and hash codes. The application fully utilizes the space-time semantic information of remote sensing videos, and further improves the retrieval performance.

The invention discloses an ECG hash coding method and system based on sample similarity guidance, and belongs to the technical field of biological signal data machine learning, and the method comprises the steps: obtaining a data set containing a plurality of ECG signals, extracting features, and constructing an ECG feature matrix; for unsupervised learning, a feature space measurement matrix and a Hash space modulation matrix are introduced, and a generalized similarity preserving equation for aligning an Euclidean space and a Hamming space is constructed in combination with an ECG feature matrix and a to-be-solved Hash coding matrix; for supervised learning, introducing a semantic space measurement matrix on the basis of unsupervised learning, and constructing generalized similarity preserving equations which simultaneously align the Euclidean space and the Hamming space and align the semantic space and the Hamming space; converting the equation into a matrix optimization problem, and solving to obtain a Hash coding matrix; and the Hash coding matrix is used for coding the ECG signal, so that the Hash coding quality and the auxiliary diagnosis retrieval efficiency can be effectively improved.

The application provides a remote sensing image retrieval optimization method based on automatic weight distribution and contrastive hashing, constructs a contrastive hashing network model based on automatic weight distribution, and adopts a two-stage training strategy to optimize the model performance. In the feature learning stage, an automatic weighted contrastive loss is proposed, a Gaussian weighting and dynamic adjustment strategy is introduced to improve the traditional loss function, different weight values are given according to the importance of sample pairs, and the learning of the model on key sample pairs is strengthened; a threshold is set to identify difficult negative samples, so that the model is not disturbed by the difficult negative samples. In the hash learning stage, the hash layer is added to convert the high-dimensional image representation into binary hash code, the quantization loss is introduced to learn the hash code after splicing and fusion, so that the semantic similar structure between data in the Hamming space can be kept, and the automatic weighted contrastive loss is used to improve the identification of the hash code. The application can effectively retrieve the target remote sensing image, and the retrieval speed is relatively fast.

The application provides a cross-modal retrieval method and device based on an attention network and an anti-hash, and the method comprises the following steps: obtaining image-text pair data, extracting initial global features of image data and text data, processing the initial global features of the image data and the initial global features of the text data through a shared attention module respectively to obtain final feature representations of the image data and the text data; a modal discriminator interacts with a feature extractor in an anti-hash manner to promote the modal feature extractor to learn better image-text features; the final feature representations of the image data and the text data are converted into binary codes, the features are mapped into a common Hamming space, cross-modal retrieval is performed, and the first K cross-modal retrieval results are obtained. The application combines an anti-hash network with a hash learning network, utilizes the anti-hash network learning to promote the feature extractor to learn modal invariant representation, simultaneously utilizes the characteristics of hash fast retrieval, and thus cross-modal retrieval is realized.

The application relates to the technical field of data retrieval, and discloses a cross-modal hash retrieval method and system with consistency, which comprises the following steps: S1. acquiring heterogeneous data; S2. acquiring hash codes of the heterogeneous data, and performing hash code learning on the heterogeneous data; S3. performing hash function learning according to the obtained optimal hash code; and S4. mapping the heterogeneous data to the same low-rank Hamming space through the hash function after the function learning is completed, using an exclusive OR operation to the similarity of the heterogeneous data and a retrieval set, returning a result with high similarity, and completing cross-modal retrieval of the heterogeneous data to be retrieved. The application solves the problems of insufficient retrieval precision and complicated optimization process in the prior art, and has the characteristics of being capable of overcoming the heterogeneity of cross modalities.

The application belongs to the technical field of information security and data retrieval, and discloses a low-misjudgment cross-modal ciphertext retrieval method based on subset predicate encryption, wherein a data owner maps data of different modes to the same Hamming space to generate binary hash codes; then, the binary hash codes are subjected to bucketing to establish an inverted index of the hash bucket number to the encrypted object identification list; then, a symmetric subset predicate encryption is used to encrypt an XOR filter to generate a lightweight encrypted index; when querying, a client generates a hash bucket number pair set to construct a search token and send it to a server once; after subset verification in the encrypted XOR filter, the server returns encrypted multi-modal data in the corresponding bucket. The application uses an XOR filter to eliminate the false positive misjudgment of a traditional Bloom filter, significantly improves retrieval accuracy, reduces server-side retrieval complexity to a constant level, and realizes low-misjudgment, high-efficiency and low-overhead cross-modal ciphertext retrieval under the premise of ensuring privacy.