Data imbalance remains a fundamental challenge in real-world machine learning. However, most existing work has focused on classification, leaving imbalanced regression underexplored despite its importance in many applications. To address this gap, we propose PRIME, a framework that leverages learnable proxies to construct a balanced and well-ordered feature space for imbalanced regression. At its core, PRIME arranges proxies to be uniformly distributed in the feature space while preserving the ordinal structure of regression targets, and then aligns each sample feature to its corresponding proxy. By using proxies as reference points, PRIME induces the desired structure of learned representations, promoting better generalization, especially in underrepresented target regions. Moreover, since proxy-based alignment resembles classification, PRIME enables the seamless application of class imbalance techniques to regression, facilitating more balanced feature learning. Extensive experiments demonstrate the effectiveness and broad applicability of PRIME, achieving state-of-the-art performance on four real-world regression benchmark datasets across diverse target domains.

Supervised learning and self-supervised learning address different facets. Supervised learning achieves high accuracy, but it requires numerous expensive labeled data indeed. Correspondingly, self-supervised learning, makes use of abundant unlabeled data to learn, but the performance lags behind that of the supervised counterpart. To overcome the difficulty of acquiring annotated data and contain the high performance in the context of speaker verification, we propose in this work a self-supervised joint learning (SS-JL) framework which complements the supervised main task with self-supervised auxiliary tasks in joint training. These auxiliary tasks help the speaker verification pipeline to generate robust speaker representation that is closely relevant to voiceprints. Our model is trained on English dataset and tested on multilingual datasets, including English, Chinese and Korean datasets, and 13.6%, 12.7% and 13.5% improvement is achieved respectively in terms of equal error rate (EER) compared with the baselines.