2results about How to "Solve computing problems" patented technology

This invention discloses a method and device for constructing a cross-island heterogeneous federated learning system based on homomorphic encryption. After local training on the client, the local model is packaged and sparsified at the packet granularity. The sparsed packet data is homomorphically encrypted, and the ciphertext and mask are sent to a parameter server. The parameter server aggregates the data according to the client's ciphertext weights and sends the aggregated ciphertext global model and mask to the client. The client decrypts the global ciphertext and unpacks it to obtain the global model, and updates its local model. The client calculates and returns a sketch of its local model. By clustering the sketch, the fastest client in each cluster is selected as a participant in the next round of training, and the contribution is calculated based on the sketch to obtain the aggregation weights for the next round. The trained local model is then applied to the cross-island heterogeneous federated learning system. This invention can improve the efficiency of homomorphic encryption while protecting privacy, and simultaneously resist the negative impact of lagging on model synchronization.

The present application provides a unified permeability directional solidification hot crack sensitivity criterion derivation method, and the method is specifically as follows: a directional solidification multi-region unified permeability calculation model is established, and the mass conservation equation and the Darcy equation are coupled, that is, the present application realizes the unified calculation of the permeability under different dendrite morphologies, and the calculation result is closer to the flow field simulation result in the numerical value; compared with the prediction result of the traditional RDG criterion, the pressure drop order of magnitude closer to the actual cracking of the liquid film is obtained; under different grain boundary energies and grain sizes, the curve morphology is close to the test result, and the double-peak effect in the hot crack sensitivity evaluation test is reproduced by the numerical simulation for the first time.