Fine-tuning and adaptation

LoRA, PEFT, instruction tuning and domain adaptation — adapting a pretrained model without paying to train one.

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arXiv Computer Vision
1d ago

ImagineAgent: What if Agents Could Imagine? Reinforcing Open-Vocabulary HOI Comprehension through Generation

arXiv:2602.11499v3 Announce Type: replace Abstract: Multimodal Large Language Models have shown promising capabilities in bridging visual and textual reasoning, yet their reasoning capabilities in Op...

By Zhenlong Yuan, Yue Wang, Dapeng Zhang, Kejin Cui, Rui Chen, Jing Tang, Lei Sun, Hongwei Yu, Chengxuan Qian, Xiangxiang Chu, Shuo Li, Yuyin Zhou
arXiv Computer Vision
1d ago

ParaVT: Taming the Tool Prior Paradox for Parallel Tool Use in Agentic Video Reinforcement Learning

arXiv:2605.20342v3 Announce Type: replace Abstract: Training large multimodal models (LMMs) via reinforcement learning (RL) to natively invoke video-processing tools (e.g., cropping) has become a pro...

By Zuhao Yang, Kaichen Zhang, Sudong Wang, Keming Wu, Zhongyu Yang, Bo Li, Xiaojuan Qi, Shijian Lu, Xingxuan Li, Lidong Bing
arXiv Computer Vision
1d ago

Lesion Overlap Ranks PET Segmentation Models but Does Not Certify Patient-Level Tumor Burden

The study evaluates whether overlap metrics like Dice can reliably indicate metabolic tumor volume (MTV) estimation accuracy in PET segmentation models. Across five FDG PET/CT models, higher Dice scores correlated with lower relative MTV error on average, but at the patient level, 16.8% of cases fell on opposite sides of clinically relevant thresholds. Additionally, many models missed lesions, showing that model ranking alone does not guarantee reliable individual MTV estimates.

By Tushar Kataria, Gerald Sabin, Ponnuswamy Sadayappan, Shireen Y. Elhabian
arXiv Computer Vision
1d ago

From Pixels to Actions - Towards Native Vision-Language-Action Policies

The paper introduces NEO-VLA, an encoder‑free vision‑language‑action framework that tokenizes images with lightweight patch convolutions and lets visual and language features evolve together throughout the backbone. By allowing a flow‑matching action expert to access instruction‑conditioned visual representations at multiple depths, NEO‑VLA consistently outperforms encoder‑based counterparts across diverse manipulation tasks and distribution shifts. Layer‑wise probing reveals that action‑critical signals peak early in the visual hierarchy, underscoring the benefit of accessing representations across the computational pipeline rather than relying on a fixed encoder output.

By Weichen Fan, Haiwen Diao, Penghao Wu, Siyuan Hu, Ziqi Huang, Tianqi Liu, Mingze Sun, Ziyi Wang, Zhongang Cai, Hanming Deng, Quan Wang, Lei Yang, Lewei Lu, Fangzhou Hong, Zhaoxi Chen, Dahua Lin, Ziwei Liu
arXiv Computer Vision
1d ago

Conditional Diffusion-Based Generation of T2-Weighted Prostate MRI for Clinically Significant Prostate Cancer Classification

The study presents a conditional diffusion-based generative model that augments T2-weighted prostate MRI data with clinically significant prostate cancer (csPCa) and transition zone (TZ) lesions. By extending MAISI‑v2 with csPCa class, zonal, and lesion‑mask conditioning and fine‑tuning on 1,303 patients, the model achieves a substantial reduction in Fréchet inception distance (FID) from 13.28 to 2.04. Synthetic augmentation improves csPCa classification AUC across five simulated training scenarios, though the benefit does not significantly transfer to a cross‑institutional dataset.

By Xavier Rafael-Palou (Quantitative Imaging Biomarkers in Medicine), Alejandro Vergara-Richart (Quantitative Imaging Biomarkers in Medicine, Universitat Polit\`ecnica de Val\`encia, Val\`encia, Spain), Ignacio Iborra Roncales (Quantitative Imaging Biomarkers in Medicine), Carmen Prieto-de-la-Lastra (Quantitative Imaging Biomarkers in Medicine), Andreu Antolin-Redondo (Department of Radiology, Institut de Diagn\`ostic per la Imatge, Department of Surgery, Universitat Aut\`onoma de Barcelona, Bellaterra, Spain), Juan Morote (Department of Surgery, Universitat Aut\`onoma de Barcelona, Bellaterra, Spain), Ana Jimenez-Pastor (Quantitative Imaging Biomarkers in Medicine)
arXiv AI
1d ago

ModalSearcher: Weaving Visual Evidence into Autonomous Cross-Modal Deep Search

ModalSearcher introduces an autonomous cross‑modal search framework that lets an agent dynamically choose among direct reasoning, text‑to‑text search, text‑to‑image search, and reverse‑image search, actively incorporating visual evidence as needed. The system builds an interleaved multimodal knowledge graph via a scalable pipeline that samples diverse paths and uses backward question construction to prevent shortcut reasoning. Trained with supervised fine‑tuning and reinforcement learning, ModalSearcher‑8B outperforms Qwen3‑VL‑8B by 16.2 accuracy points across five multimodal knowledge‑intensive QA benchmarks and shows consistent gains on active visual‑search tasks.

By Zhihan Yin, Ruyi Li, Chengyu Fang, Yifeng Yao, Nonghai Zhang, Pengfei Xiong, Terry Zhang, Huishuai Zhang, Dongyan Zhao
arXiv AI
1d ago

Intra-Architecture Source Attribution for Stable Diffusion: A New Task with Benchmark Dataset and Baseline

The paper introduces a new task, Intra-Architecture Source Attribution for Stable Diffusion (IntrAA‑SD), which focuses on distinguishing between fine‑tuned versions of the same Stable Diffusion XL architecture. It presents a 140K‑image benchmark dataset with in‑domain and out‑of‑distribution prompts, and proposes a baseline method using a style‑conditioned Mixture‑of‑Experts network that leverages a frozen CLIP backbone and a LoRA‑adapted DINOv2 network. The authors evaluate their approach on attribution accuracy and conduct ablation studies, providing code and data publicly on GitHub.

By Ashutosh Dayal, Mallika Garg, Debashis Sen
arXiv AI
1d ago

Model Merging Does Not Require Uniform LoRA Ranks

The paper investigates whether model merging requires all experts to use the same LoRA rank. Experiments with 36 experts across three domains and multiple ranks show that allowing each expert its own optimal rank improves multi‑domain accuracy by up to 1.8 percentage points, while traditional uniform‑rank methods can even degrade performance. The authors attribute this to how merge methods select spectral components, arguing that rank can be chosen per expert when the merge operator does not rely on magnitude alone.

By Zirong Xie, Zainab Afolabi, Nikita Kozodoi, Jack Butler
arXiv Computation and Language
1d ago

Towards On-Policy Data Evolution for Visual-Native Multimodal Deep Search Agents

The paper introduces a visual-native agent harness that registers every tool‑returned image as an addressable reference, enabling reuse of intermediate visual evidence in multimodal deep search tasks. It also proposes On‑Policy Data Evolution (ODE), a closed‑loop data generator that refines training data across rounds based on policy rollouts, targeting the agent’s evolving needs. Experiments on eight benchmarks show ODE boosts the Qwen3‑VL‑8B agent’s performance from 24.9% to 39.0% on average, and from 30.6% to 41.5% at 30B, while validating the benefits of image bank reuse and rollout‑feedback evolution.

By Shijue Huang, Hangyu Guo, Guanting Dong, Chenxin Li, Junting Lu, Xinyu Geng, Zhaochen Su, Zhenyu Li, Shuang Chen, Hongru Wang, Yi R. Fung
arXiv AI
1d ago

Beyond Risk Cues: A Mechanism-Level Benchmark and Verifiable Debate for Scam Video Detection on the Web

The paper introduces MechScam, a benchmark of 6,614 videos that covers diverse scam mechanisms and non‑scam content, providing evidence‑supported explanations and annotations of scam elements. It also proposes ScamCourt, a debate framework where prosecution and defense debaters argue over verified citations, and a judge decides based on the transcript. Experiments show that current large multimodal language models struggle to differentiate scam videos from similar non‑scam content, while ScamCourt reduces false positives and better resists misleading arguments.

By Yifan Wang, Junyu Lu, Shun Zhang, Chaozhuo Li, Fanliang Bu, Rong Yin, Lingbin Bu, Changrong Min, Peng Chen
arXiv AI
1d ago

Rules, Traces and Routing Statistics: Training and Calibration Data for Open Models on ARC-AGI-2

The paper reports on training and calibration experiments for three open models on the ARC‑AGI‑2 benchmark, using offline runs on four L4 GPUs for up to 12 hours. For the NVARC Qwen3‑4B grid model, a curated corpus of 12,000 executable rules and 95,993 tasks was built, and fine‑tuning on 1,920 real task records raised the semi‑private score from 28.96 to 33.06, with no synthetic‑task checkpoint outperforming the real‑task model. For the Qwen3.8‑27B reasoning model, fine‑tuning on 1,036 of its own reasoning traces and a specialized inference procedure increased the score from 26.81 to 44.03, while the Qwen3.8‑Flash‑Next mixture‑of‑experts model achieved a best score of 56.67 after expert pruning, routing statistics adaptation, and an FP8 indexer cache.

By Nguyen Minh Thang, Trinh Thi Phuong
arXiv AI
1d ago

Text-Only Domain Adaptation for Low-Resource Medical ASR: Shallow Fusion and Density Ratio Rescoring for Hausa

The study explores text-only domain adaptation for Hausa medical automatic speech recognition (ASR) using a fixed acoustic model and two decoding-time language‑model fusion techniques: Shallow Fusion (SF) and the Density Ratio Approach (DRA). A 4‑gram KenLM trained on 19,421 Hausa health sentences is combined with a 75,372‑sentence general‑domain model, and evaluated on 250 physician‑reviewed prompts from 10 speakers across six northern Nigerian states. Both fusion methods reduce word error rate (WER) from 29.56% to 23.55% (SF) and 23.33% (DRA), outperforming greedy decoding and showing no significant difference between the two approaches.

By Oche David Ankeli, Hassan Adelani Luqman, Theodora Ngozi Egbunike, Joshua Gottschalk, Bonaventure F. P. Dossou
arXiv AI
1d ago

AssameseLM-E2B: An Open-Weight Assamese Language Model for Efficient Consumer-Grade Deployment

The paper introduces AssameseLM-E2B, a 2‑billion‑parameter language model tailored for the low‑resource Assamese language, and its instruction‑tuned variant AssameseLM-E2B‑it. Built on the Gemma‑4 architecture, it uses an expanded byte‑level BPE vocabulary that cuts tokenization overhead by nearly 500 % compared with multilingual baselines, and employs a parameter‑efficient Continual Pre‑Training pipeline with Hybrid LoRA followed by supervised fine‑tuning on a balanced, multi‑domain dataset. Evaluation shows strong performance with a Bits‑per‑Byte score of 0.7488 on FLORES‑200, a 96.7 % RAG score, and 100 % refusal accuracy on adversarial prompts, highlighting the effectiveness of parameter‑efficient adaptation for locally deployable models under constrained resources.

By Pragyan Phukan