Changdi Yang

dblp:352/8666 · DBLP profile ↗
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15ranked-venue papers
4as first author
15since 2021 · last 2025
0000-0002-8848-3806ORCID · corroborated

Domains — the database's venue-derived domains; a paper can count in several

Artificial intelligence and machine learning · 11 · 2 first-author · 11 since 2021Graphics, computer vision, multimedia, augmented reality and games · 7 · 2 first-author · 7 since 2021Systems, architecture and hardware · 4 · 2 first-author · 4 since 2021
YearPublicationVenuePosition
2025 Toward Adaptive Large Language Models Structured Pruning via Hybrid-grained Weight Importance Assessment
abstract
Structured pruning for large language models (LLMs) has garnered significant academic interest due to its ability to efficiently compress and accelerate LLMs by eliminating redundant weight groups at a coarse-grained granularity. Current structured pruning methods for LLMs typically depend on a singular granularity for assessing weight importance, resulting in notable performance degradation in downstream tasks. Intriguingly, our empirical investigations reveal that utilizing unstructured pruning, which achieves better performance retention by pruning weights at a finer granularity, \emph{i.e.}, individual weights, yields significantly varied sparse LLM structures when juxtaposed to structured pruning. This suggests that evaluating both holistic and individual assessments for weight importance are essential for LLM pruning. Building on this insight, we introduce the Hybrid-grained Weight Importance Assessment (HyWIA), a novel method that merges fine-grained and coarse-grained evaluations of weight importance for the pruning of LLMs. Leveraging an attention mechanism, HyWIA adaptively determines the optimal blend of granularity in weight importance assessments in an end-to-end pruning manner. Extensive experiments on LLaMA-V1/V2, Vicuna, Baichuan, and Bloom across various benchmarks demonstrate the effectiveness of HyWIA in pruning LLMs. For example, HyWIA surpasses the cutting-edge LLM-Pruner by an average margin of 2.82% in accuracy across seven downstream tasks when pruning LLaMA-7B by 50%.
Jun Liu 0075, Zhenglun Kong, Pu Zhao 0001, Changdi Yang, Xuan Shen, Hao Tang 0005, Geng Yuan, Wei Niu 0002, Wenbin Zhang 0002, Xue Lin 0001, Yanzhi Wang 0001
AAAI4
2025 QuartDepth: Post-Training Quantization for Real-Time Depth Estimation on the Edge
abstract
Monocular Depth Estimation (MDE) has emerged as a pivotal task in computer vision, supporting numerous real-world applications. However, deploying accurate depth estimation models on resource-limited edge devices, especially Application-Specific Integrated Circuits (ASICs), is challenging due to the high computational and memory demands. Recent advancements in foundational depth estimation deliver impressive results but further amplify the difficulty of deployment on ASICs. To address this, we propose Quart-Depth which adopts post-training quantization to quantize MDE models with hardware accelerations for ASICs. Our approach involves quantizing both weights and activations to 4-bit precision, reducing the model size and computation cost. To mitigate the performance degradation, we introduce activation polishing and compensation algorithm applied before and after activation quantization, as well as a weight reconstruction method for minimizing errors in weight quantization. Furthermore, we design a flexible and programmable hardware accelerator by supporting kernel fusion and customized instruction programmability, enhancing throughput and efficiency. Experimental results demonstrate that our framework achieves competitive accuracy while enabling fast inference and higher energy efficiency on ASICs, bridging the gap between high-performance depth estimation and practical edge-device applicability. Code: https://github.com/shawnricecake/quart-depth
Xuan Shen, Weize Ma, Jing Liu 0001, Changdi Yang, Quanyi Wang, Henghui Ding, Wei Niu 0002, Yanzhi Wang 0001, Pu Zhao 0001, Jiuxiang Gu
CVPR4
2025 Squat: Quant Small Language Models on the Edge
abstract
A growing trend has emerged in designing high-quality Small Language Models (SLMs) with a few million parameters. This trend is driven by the increasing concerns over cloud costs, privacy, and latency. Considering that full parameter training is feasible for SLMs on mobile devices, Quantization-Aware Training (QAT) is employed to improve efficiency by reducing computational overhead and memory footprint. However, previous QAT works adopt fine-grained quantization methods to compress models with billions of parameters on GPUs, incompatible with current commodity hardware, such as mobile and edge devices, which relies on Single Instruction Multiple Data (SIMD) instructions. Thus, the generalization of these methods to SLMs on mobile devices is limited. In this paper, we propose Squat method, an effective QAT framework with deployable quantization for SLMs on mobile devices. Specifically, we propose entropy-guided and distribution-aligned distillation to mitigate the distortion of attention information from quantization. Besides, we employ sub-8-bit token adaptive quantization, assigning varying bit widths to different tokens based on their importance. Furthermore, we develop a SIMD-based Multi-Kernel Mixed-Precision (MKMP) multiplier to support sub-8-bit mixed-precision MAC on mobile devices. Our extensive experiments verify the substantial improvements of our method compared to other QAT methods across various datasets. Furthermore, we achieve an on-device speedup of up to 2.37× compared with its FP16 counterparts, signaling a great advancement. Code: https://github.com/shawnricecake/squant
Xuan Shen, Peiyan Dong, Zhenglun Kong, Yifan Gong 0004, Changdi Yang, Yanyue Xie, Chao Wu 0006, Yanzhi Wang 0001, Pu Zhao 0001
ICCAD5
2025 Sparse Learning for State Space Models on Mobile
abstract
Transformer models have been widely investigated in different domains by providing long-range dependency handling and global contextual awareness, driving the development of popular AI applications such as ChatGPT, Gemini, and Alexa. State Space Models (SSMs) have emerged as strong contenders in the field of sequential modeling, challenging the dominance of Transformers. SSMs incorporate a selective mechanism that allows for dynamic parameter adjustment based on input data, enhancing their performance. However, this mechanism also comes with increasing computational complexity and bandwidth demands, posing challenges for deployment on resource-constraint mobile devices. To address these challenges without sacrificing the accuracy of the selective mechanism, we propose a sparse learning framework that integrates architecture-aware compiler optimizations. We introduce an end-to-end solution--$\mathbf{C}_4^n$ kernel sparsity, which prunes $n$ elements from every four contiguous weights, and develop a compiler-based acceleration solution to ensure execution efficiency for this sparsity on mobile devices. Based on the kernel sparsity, our framework generates optimized sparse models targeting specific sparsity or latency requirements for various model sizes. We further leverage pruned weights to compensate for the remaining weights, enhancing downstream task performance. For practical hardware acceleration, we propose $\mathbf{C}_4^n$-specific optimizations combined with a layout transformation elimination strategy. This approach mitigates inefficiencies arising from fine-grained pruning in linear layers and improves performance across other operations. Experimental results demonstrate that our method achieves superior task performance compared to other semi-structured pruning methods and achieves up-to 7$\times$ speedup compared to llama.cpp framework on mobile devices.
Xuan Shen, Hangyu Zheng, Yifan Gong 0004, Zhenglun Kong, Changdi Yang, Zheng Zhan 0001, Yushu Wu, Xue Lin 0001, Yanzhi Wang 0001, Pu Zhao 0001, Wei Niu 0002
ICLR5
2025 FairSMOE: Mitigating Multi-Attribute Fairness Problem with Sparse Mixture-of-Experts
abstract
Real‐world datasets usually contain multiple attributes, making it essential to ensure fairness across all of them simultaneously. However, different attributes may vary in difficulty, and no existing approaches have effectively addressed this issue. Consequently, an attribute‐adaptive strategy is needed to achieve fairness for all attributes. Multi‐task Learning (MTL) leverages shared information to optimize multiple tasks concurrently, while Sparsely‐Gated Mixture‐of‐Experts (SMoE) can dynamically allocate computational resources to the most needed tasks. In this work, we formulate multi‐attribute fairness issue as an MTL problem and employ SMoE to achieve desirable performance across all attributes simultaneously. We first analyze the feasibility and find the potentiality by formalizing multi-attribute fairness problem into a MTL problem and mitigating it by using SMoE. However, vanilla SMoE could lead to over-utilization problem which causes sub-optimal performance. We then proposed an innovative SMoE framework for multi-attribute fair image classification, which further improves multi-attribute fairness by redesigning the MoE layer and routing policy with fairness consideration. Extensive experiments demonstrated the effectiveness. Taking a DeiT-Small as the backbone, we achieve 77.25% and 86.01% accuracy on the ISIC2019 and CelebA dataset respectively with Multi-attribute Predictive Quality Disparity (PQD) score of 0.801 and 0.787, beating current state-of-the-art methods Muffin, InfoFair and MultiFair.
Changdi Yang, Zheng Zhan 0001, Ci Zhang, Yifan Gong 0004, Zichong Meng, Jun Liu 0075, Xuan Shen, Hao Tang 0005, Geng Yuan, Pu Zhao 0001, Xue Lin 0001, Yanzhi Wang 0001
IJCAI1
2025 ALTER: All-in-One Layer Pruning and Temporal Expert Routing for Efficient Diffusion Generation
abstract
Diffusion models have demonstrated exceptional capabilities in generating high-fidelity images. However, their iterative denoising process results in significant computational overhead during inference, limiting their practical deployment in resource-constrained environments. Existing acceleration methods often adopt uniform strategies that fail to capture the temporal variations during diffusion generation, while the commonly adopted sequential $\textit{pruning-then-fine-tuning strategy}$ suffers from sub-optimality due to the misalignment between pruning decisions made on pretrained weights and the model’s final parameters. To address these limitations, we introduce $\textbf{ALTER}$: $\textbf{A}$ll-in-One $\textbf{L}$ayer Pruning and $\textbf{T}$emporal $\textbf{E}$xpoert $\textbf{R}$outing, a unified framework that transforms diffusion models into a mixture of efficient temporal experts. ALTER achieves a single-stage optimization that unifies layer pruning, expert routing, and model fine-tuning by employing a trainable hypernetwork, which dynamically generates layer pruning decisions and manages timestep routing to specialized, pruned expert sub-networks throughout the ongoing fine-tuning of the UNet. This unified co-optimization strategy enables significant efficiency gains while preserving high generative quality. Specifically, ALTER achieves same-level visual fidelity to the original 50-step Stable Diffusion v2.1 model while utilizing only 25.9\% of its total MACs with just 20 inference steps and delivering a 3.64$\times$ speedup through 35\% sparsity.
Qihui Fan, Changdi Yang, Juyi Lin, Yanzhi Wang 0001, Shangqian Gao
NeurIPS4
2025 TSLA: A Task-Specific Learning Adaptation for Semantic Segmentation on Autonomous Vehicles Platform
abstract
Autonomous driving platforms encounter diverse driving scenarios, each with varying hardware resources and precision requirements. Given the computational limitations of embedded devices, it is crucial to consider computing costs when deploying on target platforms like the DRIVE PX 2. Our objective is to customize the semantic segmentation network according to the computing power and specific scenarios of autonomous driving hardware. We implement dynamic adaptability through a three-tier control mechanism—width multiplier, classifier depth, and classifier kernel—allowing fine-grained control over model components based on hardware constraints and task requirements. This adaptability facilitates broad model scaling, targeted refinement of the final layers, and scenario-specific optimization of kernel sizes, leading to improved resource allocation and performance. Additionally, we leverage Bayesian Optimization with surrogate modeling to efficiently explore hyperparameter spaces under tight computational budgets. Our approach addresses scenario-specific and task-specific requirements through automatic parameter search, accommodating the unique computational complexity and accuracy needs of autonomous driving. It scales its multiply-accumulate operations (MACs) for task-specific learning adaptation (TSLA), resulting in alternative configurations tailored to diverse self-driving tasks. These TSLA customizations maximize computational capacity and model accuracy, optimizing hardware utilization.
Jun Liu 0075, Zhenglun Kong, Pu Zhao 0001, Weihao Zeng 0002, Hao Tang 0005, Xuan Shen, Changdi Yang, Wenbin Zhang 0002, Geng Yuan, Wei Niu 0002, Xue Lin 0001, Yanzhi Wang 0001
IEEE Trans. Comput. Aided Des. Integr. Circuits Syst.7
2024 InstructGIE: Towards Generalizable Image Editing
Zichong Meng, Changdi Yang, Jun Liu 0075, Hao Tang 0005, Pu Zhao 0001, Yanzhi Wang 0001
ECCV (88)2
2024 DiffClass: Diffusion-Based Class Incremental Learning
Zichong Meng, Changdi Yang, Zheng Zhan 0001, Pu Zhao 0001, Yanzhi Wang 0001
ECCV (87)3
2024 Rethinking Token Reduction for State Space Models
abstract
Recent advancements in State Space Models (SSMs) have attracted significant interest, particularly in models optimized for parallel training and handling long-range dependencies.Architectures like Mamba have scaled to billions of parameters with selective SSM.To facilitate broader applications using Mamba, exploring its efficiency is crucial.While token reduction techniques offer a straightforward post-training strategy, we find that applying existing methods directly to SSMs leads to substantial performance drops.Through insightful analysis, we identify the reasons for this failure and the limitations of current techniques.In response, we propose a tailored, unified post-training token reduction method for SSMs.Our approach integrates token importance and similarity, thus taking advantage of both pruning and merging, to devise a fine-grained intra-layer token reduction strategy.Extensive experiments show that our method improves the average accuracy by 5.7% to 13.1% on six benchmarks with Mamba-2 compared to existing methods, while significantly reducing computational demands and memory requirements.1
Zheng Zhan 0001, Yushu Wu, Zhenglun Kong, Changdi Yang, Yifan Gong 0004, Xuan Shen, Xue Lin 0001, Pu Zhao 0001, Yanzhi Wang 0001
EMNLP4
2024 Fast and Memory-Efficient Video Diffusion Using Streamlined Inference
abstract
The rapid progress in artificial intelligence-generated content (AIGC), especially with diffusion models, has significantly advanced development of high-quality video generation. However, current video diffusion models exhibit demanding computational requirements and high peak memory usage, especially for generating longer and higher-resolution videos. These limitations greatly hinder the practical application of video diffusion models on standard hardware platforms. To tackle this issue, we present a novel, training-free framework named Streamlined Inference, which leverages the temporal and spatial properties of video diffusion models. Our approach integrates three core components: Feature Slicer, Operator Grouping, and Step Rehash. Specifically, Feature Slicer effectively partitions input features into sub-features and Operator Grouping processes each sub-feature with a group of consecutive operators, resulting in significant memory reduction without sacrificing the quality or speed. Step Rehash further exploits the similarity between adjacent steps in diffusion, and accelerates inference through skipping unnecessary steps. Extensive experiments demonstrate that our approach significantly reduces peak memory and computational overhead, making it feasible to generate high-quality videos on a single consumer GPU (e.g., reducing peak memory of Animatediff from 42GB to 11GB, featuring faster inference on 2080Ti).
Zheng Zhan 0001, Yushu Wu, Yifan Gong 0004, Zichong Meng, Zhenglun Kong, Changdi Yang, Geng Yuan, Pu Zhao 0001, Wei Niu 0002, Yanzhi Wang 0001
NeurIPS6
2023 Towards Real-Time Segmentation on the Edge
abstract
The research in real-time segmentation mainly focuses on desktop GPUs. However, autonomous driving and many other applications rely on real-time segmentation on the edge, and current arts are far from the goal. In addition, recent advances in vision transformers also inspire us to re-design the network architecture for dense prediction task. In this work, we propose to combine the self attention block with lightweight convolutions to form new building blocks, and employ latency constraints to search an efficient sub-network. We train an MLP latency model based on generated architecture configurations and their latency measured on mobile devices, so that we can predict the latency of subnets during search phase. To the best of our knowledge, we are the first to achieve over 74% mIoU on Cityscapes with semi-real-time inference (over 15 FPS) on mobile GPU from an off-the-shelf phone.
Yanyu Li, Changdi Yang, Pu Zhao 0001, Geng Yuan, Wei Niu 0002, Jiexiong Guan, Hao Tang 0005, Minghai Qin, Qing Jin, Bin Ren 0002, Xue Lin 0001, Yanzhi Wang 0001
AAAI2
2023 Pruning Parameterization with Bi-level Optimization for Efficient Semantic Segmentation on the Edge
abstract
With the ever-increasing popularity of edge devices, it is necessary to implement real-time segmentation on the edge for autonomous driving and many other applications. Vision Transformers (ViTs) have shown considerably stronger results for many vision tasks. However, ViTs with the fullattention mechanism usually consume a large number of computational resources, leading to difficulties for real- time inference on edge devices. In this paper, we aim to derive ViTs with fewer computations and fast inference speed to facilitate the dense prediction of semantic segmentation on edge devices. To achieve this, we propose a pruning parameterization method to formulate the pruning problem of semantic segmentation. Then we adopt a bi-level optimization method to solve this problem with the help of implicit gradients. Our experimental results demonstrate that we can achieve 38.9 mIoU on ADE20K val with a speed of 56.5 FPS on Samsung S21, which is the highest mIoU under the same computation constraint with real-time inference.
Changdi Yang, Pu Zhao 0001, Yanyu Li, Wei Niu 0002, Jiexiong Guan, Hao Tang 0005, Minghai Qin, Bin Ren 0002, Xue Lin 0001, Yanzhi Wang 0001
CVPR1
2023 Late Breaking Results: Fast Fair Medical Applications? Hybrid Vision Models Achieve the Fairness on the Edge
abstract
As edge devices become readily available and indispensable, there is an urgent need for effective and efficient intelligent applications to be deployed widespread. However, fairness has always been an issue, especially in edge medical applications. Compared to convolutional neuron networks (CNNs), Vision Transformer (ViT) has a better ability to extract global information, which will contribute to alleviating the unfairness problem. Typically, ViTs consume large amounts of computational and memory resources, which hinders their usage on edge. In this work, we propose a novel hardware-efficient Vision Model search framework for the fair dermatology classification, namely HeViFa. Experimental results show that HeViFa could search for a hybrid ViT model that reaches 173.1 FPS on a Samsung S21 mobile phone with 85.71% accuracy on the light skin dataset and 80.85% accuracy on the dark skin dataset. Note that HeViFa can reach both the highest accuracy and fairness under similar latency constrain on multiple edge devices (Samsung S21 mobile phone, iPhone 13 Pro and Raspberry PI).
Changdi Yang, Yi Sheng 0001, Peiyan Dong, Zhenglun Kong, Yanyu Li, Pinrui Yu, Lei Yang 0018, Xue Lin 0001
DAC1
2023 Fast and Fair Medical AI on the Edge Through Neural Architecture Search for Hybrid Vision Models
abstract
As edge devices become readily available and indispensable, there is an urgent need for effective and efficient intelligent applications to be deployed widespread. However, fairness has always been an issue, especially in edge medical applications. Although many approaches have been proposed to mitigate the unfairness problem, their edge performance is not desirable. By examining the fairness performance of different network architectures, we observed that compared to pure convolutional neuron network (CNN) architecture, hybrid models with CNN and Vision Transformer (ViT) have exhibited better performance in terms of fairness and accuracy. After further analyzing the feature maps of intermediate layers of CNNs, ViTs, and hybrid models, we found that ViT has a strong ability to extract global information, which contributes to alleviating the unfairness problem. However, ViTs consume large amounts of computational and memory resources, which hinders their application on edge devices. To address the challenges abovementioned, we propose the first hardware-oriented co-design NAS framework to explore hybrid ViT-CNN architecture for the fair dermatology classification, namely HeViFa, which can produce light-weight models for edge devices with low unfairness scores and high classification accuracy. Experimental results show that compared with FaHaNa-Small, HeViFa-Small could search for a hybrid ViT model that reaches 10.57% and 4.03% higher accuracy as well as 0.179 and 0.0403 higher PQD score on Mix and Fitzpatrick17k dataset, repectively, and speed up by 1.21 × on Samsung S21 mobile phone, 1.18 × on iPhone 13 Pro and 1.37 × on Raspberry Pi.
Changdi Yang, Yi Sheng 0001, Peiyan Dong, Zhenglun Kong, Yanyu Li, Pinrui Yu, Lei Yang 0018, Xue Lin 0001, Yanzhi Wang 0001
ICCAD1