SDE : Scale-Difference Evolution Knowledge Distillation

Streamlined Knowledge Distillation

Rethinking Reverse KL as Adaptive Entropy Distillation

This work revisits on-policy Reverse Kullback-Leibler distillation and decomposes its objective into a teacher-fitting term and a student-entropy term, without introducing an explicit FKL branch, and proposes Adaptive Entropy Distillation (AED), which uses the teacher's entropy to dynamically calibrate token-level imitation strength.

EMPURPLE: A Free Lunch for Diffusion Distillation based on the Information Bottleneck

Diffusion models achieve impressive image-generation quality but remain expensive at inference time. Diffusion distillation reduces sampling steps, yet many distilled models, including SDXL-Lightning and distribution matching distillation methods, suffer from degraded Fr\'echet Inception Distance (FID). We analyze this phenomenon through a PAC-style generalization bound. Our analysis suggests that aggressive early-step redirection of the velocity field makes the distillation target harder to learn, enlarging the train-test gap. As a result, early-step output distributions differ between training and inference, causing distribution mismatch in the intermediate noisy latent used as next-step inputs. We empirically validate this mechanism by showing reduced diversity in both intermediate features and final outputs. To address this issue, we propose EMPURPLE, a simple training-free method that recycles intermediate latents sampled from the original model. EMPURPLE is model-agnostic and improves FID by 7\% to 20\% across DMD2, Hyper-SD, FlashSD, and SDXL-Lightning. The repo is: https://github.com/TheLovesOfLadyPurple/Empurple-Training-Free-Algorithm-To-enhance-Diversity-of-The-Diffusion-Distillation-Model

D3O: Dynamic Distribution Distillation for Ordinal Regression

Ordinal regression is widely used in scenarios where labels are discrete yet inherently ordered. In practice, however, ordinal labels are often obtained by discretizing underlying continuous semantics through subjective human judgment, resulting in ambiguous boundaries and annotation noise. Such uncertainty challenges existing methods that rely on fixed supervision targets, which may reinforce biased ordering under subjective annotations. To address this limitation, we propose D3O, a dynamic distribution distillation framework that replaces static supervision with training-driven evolution of ordinal label distributions via self-distillation. Specifically, we introduce a contrastive ordinal-aware label enhancement module that leverages vision-language alignment to recover refined label distributions capturing both inter-class ambiguity and instance-level uncertainty. Furthermore, we design a CDF-based cross-layer interaction distillation mechanism to propagate cumulative ordinal structure across network hierarchy, ensuring consistent ordinal geometry in intermediate representations. Extensive experiments on four general ordinal regression tasks demonstrate that our proposed D3O consistently outperforms existing approaches, particularly under severe class imbalance and noisy supervision. These results highlight the effectiveness of dynamic supervision in learning robust ordinal representations beyond fixed targets. The code will be publicly available.

Making Knowledge Distillation Open Again

Knowledge distillation (KD) has become a pivotal technique for transferring knowledge from large-scale teacher models to lightweight student models. However, traditional feature-based distillation methods necessitate the direct exposure of the teacher’s intermediate representations, raising concerns regarding data privacy and the leakage of proprietary model details. These concerns often hinder the deployment of distillation in collaborative or cloud-based scenarios. To address these challenges, we propose a privacy-aware teacher-oriented projected feature distillation framework that reduces direct feature exposure while preserving distillation effectiveness. Specifically, our method employs a low-rank projection strategy to obfuscate the teacher’s features into a compact subspace. Authorized student models leverage this projection matrix to align their own features, enabling effective knowledge transfer while reducing direct exposure of the teacher’s original spatial patterns. Extensive experiments on benchmark datasets demonstrate empirical feature obfuscation and reconstruction resistance while maintaining competitive performance in object detection and semantic segmentation, with gains in several settings even when learning from projected representations.

Streamlining Long-Chain Reasoning via Differentiable Hierarchical Fusion

Differentiable Hierarchical Fusion is presented, a novel framework that merges reasoning models with efficient base models via differentiable optimization to produce concise, accurate outputs and introduces a dual-factor adaptive weighting mechanism to capture intra-block variance and inter-block importance hierarchies, thereby addressing key limitations of static merging heuristics.