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Feiyu Tao

Publications and source records attributed to Feiyu Tao.

2 recordsLinked to original sources

PHYBench: Holistic Evaluation of Physical Perception and Reasoning in Large Language Models

Current benchmarks for evaluating the reasoning capabilities of Large Language Models (LLMs) face significant limitations: task oversimplification, data contamination, and flawed evaluation items. These deficiencies necessitate more rigorous assessment methods. To address these limitations, we introduce PHYBench, a benchmark of 500 original physics problems ranging from high school to Physics Olympiad difficulty. PHYBench addresses data contamination through original content and employs a systematic curation pipeline to eliminate flawed items. Evaluations show that PHYBench activates more tokens and provides stronger differentiation between reasoning models compared to other baselines like AIME 2024, OlympiadBench and GPQA. Even the best-performing model, Gemini 2.5 Pro, achieves only 36.9% accuracy compared to human experts' 61.9%. To further enhance evaluation precision, we introduce the Expression Edit Distance (EED) Score for mathematical expression assessment, which improves sample efficiency by 204% over binary scoring. Moreover, PHYBench effectively elicits multi-step and multi-condition reasoning, providing a platform for examining models' reasoning robustness, preferences, and deficiencies. The benchmark results and dataset are publicly available at https://www.phybench.cn/.

cs.CL

Creasing of an everted elastomer tube

A cylindrical elastomer tube can stay in an everted state without any applied external forces. If the thickness of the tube is small, the everted tube, except for the regions close to the two ends of the tube, is cylindrical, if the thickness is larger than a critical value, the cross-section of the everted tube becomes noncircular, which is due to mechanical instability. Although the eversion-induced mechanical instability in an elastomer tube has been reported several decades ago, a satisfying explanation of the phenomenon is still unavailable. In all previous studies, linear stability analyses have been commonly adopted to predict the critical thickness of the tube for the eversion-induced instability. The discrepancy between the prediction and experiment is significant and well known. In this letter, based on the experiments and theoretical analyses, we show that crease formation on the inner surface of an everted tube is the mechanical instability mode, which cannot be captured by linear stability analyses. Instead, a combination of energetic analyses and numerical simulation of highly nonlinear deformation enables us to correctly predict both the critical thickness of the tube for the onset of creases and the profile of the cross-section of an everted tube with multiple creases on its inner surface.

cond-mat.soft