Abstract: Methods, systems, and apparatus, including computer programs encoded on computer storage media, for updating embeddings for user accounts on a social messaging platform. One of the methods includes receiving data having multiple data tuples, each data tuple indicating a user account and an item that the user account engaged with on the social messaging platform. A portion of the data is assigned to a respective multiple clusters. Embeddings are updated using an assigned cluster for each portion of the data. The updating includes: for each iteration step of multiple iteration steps, first embeddings are updated based on a first variable coefficient and a second variable coefficient. The updated first embeddings are stored into respective temporary data structures, which are then aggregated to generate aggregated first embeddings in a preserved data structure. Second embeddings are updated based on the aggregated first embeddings.

Abstract: A system and method for adversarial vulnerability testing of machine learning models is proposed that receives as an input, a representation of a non-differentiable machine learning model, transforms the input model into a smoothed model and conducts an adversarial search against the smoothed model to generate an output data value representative of a potential vulnerability to adversarial examples. Variant embodiments are also proposed, directed to noise injection, hyperparameter control, and exhaustive/sampling-based searches in an effort to balance computational efficiency and accuracy in practical implementation. Flagged vulnerabilities can be used to have models re-validated, re-trained, or removed from use due to an increased cybersecurity risk profile.

Abstract: Systems and methods for machine learning architecture for out-of-distribution data detection. The system may include a processor and a memory storing processor-executable instructions that may, when executed, configure the processor to: receive an input data set; generate an out-of-distribution prediction based on the input data set and an auto-encoder, the auto-encoder trained based on a pretext task including a transformation of one or more training data sets for reconstruction, the trained auto-encoder trained for reducing a reconstruction error to encode semantic meaning of the training data sets; and generate a signal for providing an indication of whether the input data set is an out-of-distribution data set.

Abstract: A recommendation system models unknown preferences as samples from a noise distribution to generate recommendations for an online system. Specifically, the recommendation system obtains latent user and item representations from preference information that are representations of users and items in a lower-dimensional latent space. A recommendation for a user and item with an unknown preference can be generated by combining the latent representation for the user with the latent representation for the item. The latent user and item representations are learned to discriminate between observed interactions and unobserved noise samples in the preference information by increasing estimated predictions for known preferences in the ratings matrix, and decreasing estimated predictions for unobserved preferences sampled from the noise distribution.

Abstract: A recommendation system models unknown preferences as samples from a noise distribution to generate recommendations for an online system. Specifically, the recommendation system obtains latent user and item representations from preference information that are representations of users and items in a lower-dimensional latent space. A recommendation for a user and item with an unknown preference can be generated by combining the latent representation for the user with the latent representation for the item. The latent user and item representations are learned to discriminate between observed interactions and unobserved noise samples in the preference information by increasing estimated predictions for known preferences in the ratings matrix, and decreasing estimated predictions for unobserved preferences sampled from the noise distribution.