Machine learning system with two encoder towers for semantic matching

A computer-implemented method of identifying one or more chemical reaction procedures from a chemical reaction sketch comprising:

• receiving from a user computing device the chemical reaction sketch;
• tokenizing the chemical reaction sketch to create a reaction token sequence;
• generating a reaction embedding from the reaction token sequence by a reaction encoder of a contrastive learning based two-tower model, the contrastive learning based two-tower model trained by contrastive loss on training data that includes training chemical reactions and training chemical reaction procedures for performing the training chemical reactions;
• determining similarity between the reaction embedding and procedure embeddings in a shared embedding space, the procedure embeddings generated by a procedure encoder of the contrastive learning based two-tower model from chemical reaction procedures in a corpus of chemical reaction procedures;
• and
• outputting a predetermined number of candidate chemical reaction procedures corresponding to procedure embeddings having a highest similarity to the reaction embedding.

A computer-implemented method of training a machine learning system for identifying chemical reaction procedures from chemical reaction sketches comprising:

• accessing training data from a training datastore, the training data comprising labeled data pairs of training chemical reactions and training chemical reaction procedures for performing the chemical reactions;
• tokenizing the training chemical reactions from the training data to create reaction token sequences;
• providing the reaction token sequences to a reaction encoder that generates reaction embeddings in a shared embedding space;
• tokenizing the training chemical reaction procedures from the training data to create procedure token sequences;
• providing the procedure token sequences to a procedure encoder that generates procedure embeddings in the shared embedding space;
• and
• training the reaction encoder and the procedure encoder with the training data by backpropagation to minimize a loss function between corresponding pairs of the reaction embeddings and the procedure embeddings.