Recent large language models (LLMs) with long-chain-of-thought reasoning—such as DeepSeek-R1—have achieved impressive results on Olympiad-level mathematics benchmarks. However, they often rely on a narrow set of strategies and struggle with problems that require a novel way of thinking. To systematically investigate these limitations, we introduce OMEGA—Out-of-distribution Math Problems Evaluation with 3 Generalization Axes—a controlled yet diverse bench- mark designed to evaluate three axes of out-of-distribution generalization, inspired by Boden’s typology of creativity: (1) Exploratory—applying known problem- solving skills to more complex instances within the same problem domain; (2) Com- positional—combining distinct reasoning skills, previously learned in isolation, to solve novel problems that require integrating these skills in new and coherent ways; and (3) Transformative—adopting novel, often unconventional strategies by moving beyond familiar approaches to solve problems more effectively. OMEGA consists of programmatically generated training–test pairs derived from templated problem generators across geometry, number theory, algebra, combinatorics, logic, and puzzles, with solutions verified using symbolic, numerical, or graphical methods. We evaluate frontier (or top-tier) LLMs and observe sharp performance degradation as problem complexity increases. Moreover, we fine-tune the Qwen-series models across all generalization settings and observe notable improvements in exploratory generalization, while compositional generalization remains limited, and transformative reasoning shows little to no improvement. By isolating and quantifying these fine-grained failures, OMEGA lays the groundwork for advancing LLMs toward genuine mathematical creativity beyond mechanical proficiency. Our code and dataset are available at https://github.com/sunblaze-ucb/omega.

Multimodal Sentiment Analysis (MSA) is a popular research topic aimed at utilizing multimodal signals for understanding human emotions. The primary approach to solving this task is to develop complex fusion techniques. However, the heterogeneity and unaligned nature between modalities pose significant challenges to fusion. Additionally, existing methods lack consideration for the efficiency of modal fusion. To tackle these issues, we propose AcFormer, which contains two core ingredients: i) contrastive learning within and across modalities to explicitly align different modality streams before fusion; and ii) pivot attention for multimodal interaction/fusion. The former encourages positive triplets of image-audio-text to have similar representations in contrast to negative ones. The latter introduces attention pivots that can serve as cross-modal information bridges and limit cross-modal attention to a certain number of fusion pivot tokens. We evaluate AcFormer on multiple MSA tasks, including multimodal emotion recognition, humor detection, and sarcasm detection. Empirical evidence shows that AcFormer achieves the optimal performance with minimal computation cost compared to previous state-of-the-art methods. Our code is publicly available at https://github.com/dingchaoyue/AcFormer.

In this paper, we present the solutions to the MER-MULTI and MER-NOISE sub-challenges of the Multimodal Emotion Recognition Challenge (MER 2023). For the tasks MER-MULTI and MER-NOISE, participants are required to recognize both discrete and dimensional emotions. Particularly, in MER-NOISE, the test videos are corrupted with noise, necessitating the consideration of modality robustness. Our empirical findings indicate that different modalities contribute differently to the tasks, with a significant impact from the audio and visual modalities, while the text modality plays a weaker role in emotion prediction. To facilitate subsequent multimodal fusion, and considering that language information is implicitly embedded in large pre-trained speech models, we have made the deliberate choice to abandon the text modality and solely utilize visual and acoustic modalities for these sub-challenges. To address the potential underfitting of individual modalities during multimodal training, we propose to jointly train all modalities via a weighted blending of supervision signals. Furthermore, to enhance the robustness of our model, we employ a range of data augmentation techniques at the image level, waveform level, and spectrogram level. Experimental results show that our model ranks 1st in both MER-MULTI (0.7005) and MER-NOISE (0.6846) sub-challenges, validating the effectiveness of our method. Our code is publicly available at https://github.com/dingchaoyue/Multimodal-Emotion-Recognition-MER-and-MuSe-2023-Challenges.

Grapheme-to-phoneme (G2P) conversion is an indispensable part of the Chinese Mandarin text-to-speech (TTS) system, and the core of G2P conversion is to solve the problem of polyphone disambiguation, which is to pick up the correct pronunciation for several candidates for a Chinese polyphonic character.In this paper, we propose a Chinese polyphone BERT model to predict the pronunciations of Chinese polyphonic characters.Firstly, we create 741 new Chinese monophonic characters from 354 source Chinese polyphonic characters by pronunciation.Then we get a Chinese polyphone BERT by extending a pre-trained Chinese BERT with 741 new Chinese monophonic characters and adding a corresponding embedding layer for new tokens, which is initialized by the embeddings of source Chinese polyphonic characters.In this way, we can turn the polyphone disambiguation task into a pre-training task of the Chinese polyphone BERT.Experimental results demonstrate the effectiveness of the proposed model, and the polyphone BERT model obtain 2% (from 92.1% to 94.1%) improvement of average accuracy compared with the BERT-based classifier model, which is the prior state-of-the-art in polyphone disambiguation.