Enjun Du
Author directory2026
SnapBench: Benchmarking Snap-and-Ask Multimodal Retrieval for Mobile Interactions
Zirong Chen | Fuda Ye | Kuan Zhang | Enjun Du | Junfu Pu | Xinlei Wang | Xinyu Zuo | Lisheng Duan | Jin Ma | Yongqi Zhang
Findings of the Association for Computational Linguistics: EMNLP 2026
Zirong Chen | Fuda Ye | Kuan Zhang | Enjun Du | Junfu Pu | Xinlei Wang | Xinyu Zuo | Lisheng Duan | Jin Ma | Yongqi Zhang
Findings of the Association for Computational Linguistics: EMNLP 2026
Mobile AI acts as a visual oracle, empowering users to snap a picture of something and ask for information. Snap-and-ask retrieval is now one of the most common entry points for mobile AI, yet photos are often blurry, while text questions may be short or mistyped. Existing benchmarks only test on clean inputs or do not isolate paired robustness in snap-and-ask retrieval. Therefore, we introduce SnapBench, the first paired benchmark for robust snap-and-ask multimodal retrieval, spanning 1,145 queries, 9,085 gallery items under 53 controlled corruption conditions with human annotations. We evaluate 16 multimodal retrievers, covering dual-tower encoders and embedding-based VLMs. Results show that image corruptions substantially degrade retrieval, while text corruptions mainly affect text-only retrieval and have limited impact on joint retrieval. Clean image-only retrieval often outperforms joint retrieval, indicating the coarse-text drag and the lack of cross-modal fallback under noisy inputs. SnapBench provides a controlled testbed for evaluating robust retrieval in snap-and-ask scenarios. We further propose MOOR (Modality-anchored, Outlier-aware, Optimal Reweighting), a simple adaptive fusion approach, highlighting the need for reliability-aware modality calibration in snap-and-ask retrieval. The code and dataset are available at https://github.com/zrchen03/SnapBench.
EviRank: Structured Relevance Evidence for Multimodal Image Re-ranking
Enjun Du | Siyi Liu | Zirong Chen | Xinyu Zuo | Jinwen Luo | Ruiwen Tao | Lisheng Duan | Haijin Liang | Jin Ma | Junfu Pu | Yongqi Zhang
Proceedings of the 2026 Conference on Empirical Methods in Natural Language Processing
Enjun Du | Siyi Liu | Zirong Chen | Xinyu Zuo | Jinwen Luo | Ruiwen Tao | Lisheng Duan | Haijin Liang | Jin Ma | Junfu Pu | Yongqi Zhang
Proceedings of the 2026 Conference on Empirical Methods in Natural Language Processing
Real-world image search queries are multimodal and compositional: “find this shirt in pink” specifies an entity to retain, an attribute to modify, and context to ignore. Yet existing re-rankers either compress such multi-faceted relevance into an opaque embedding or rely on free-form chain-of-thought that easily omits or hallucinates fine-grained constraints. Drawing on rubric- and checklist-based evaluation from NLP, we recast multimodal image re-ranking as a semantic constraint satisfaction problem and propose EviRank, which parses any query—text-only, image-only, or composed—into a unified evidence package: typed criteria across six semantic slots (e.g., entities, attributes, relations), each labelled required, forbidden, or ignorable. Re-ranking then reduces to evidence-conditioned verification, combining deterministic rubric scoring and evidence-grounded listwise comparison in a single training-free procedure. The explicit evidence can further serve as structured supervision for optionally distilling a lightweight student. Across five benchmarks spanning text-to-image, image-to-image, and composed image retrieval, EviRank achieves state-of-the-art performance, and the distilled student preserves over 90% of the teacher’s capability at substantially lower cost.
RePair: Turning Retrieval Failures into Counterfactual Hard Pairs
Siyi Liu | Xiaorong Zhu | Enjun Du | Xinyu Zuo | Lisheng Duan | Haijin Liang | Jin Ma | Junfu Pu | Yongqi Zhang
Proceedings of the 2026 Conference on Empirical Methods in Natural Language Processing
Siyi Liu | Xiaorong Zhu | Enjun Du | Xinyu Zuo | Lisheng Duan | Haijin Liang | Jin Ma | Junfu Pu | Yongqi Zhang
Proceedings of the 2026 Conference on Empirical Methods in Natural Language Processing
Vision-language retrieval with CLIP-style dual encoders achieves strong cross-modal performance, yet practical accuracy often hinges on localized semantic distinctions where top-ranked near misses differ from the true match by a single critical detail. Hard-sample mining can select confusable candidates but cannot construct corrected counterparts; synthetic augmentation can generate novel samples but, without conditioning on actual model failures, targets irrelevant dimensions of hardness. We observe that a top-ranked false positive is a counterfactual scaffold—sharing most of the query’s semantics while differing in a localized failure-causing residual. Minimally correcting this residual yields a hard positive of the ground truth in the same modality; the corrected and unedited versions form a hard negative pair that straddles the decision boundary, producing complementary pull–push supervision. We introduce RePair, guided by three principles—Validity, Minimality, and Locality—which mines false positives bidirectionally, applies LLM-guided counterfactual editing, and trains with a local hard-pair contrastive objective. On Flickr30K and COCO30K, RePair outperforms controlled augmentation baselines with only 107K synthetic samples—26%–75% fewer than comparable methods—confirming failure-conditioned repair is more data-efficient than error-agnostic augmentation.
2025
Mixture of Length and Pruning Experts for Knowledge Graphs Reasoning
Enjun Du | Siyi Liu | Yongqi Zhang
Proceedings of the 2025 Conference on Empirical Methods in Natural Language Processing
Enjun Du | Siyi Liu | Yongqi Zhang
Proceedings of the 2025 Conference on Empirical Methods in Natural Language Processing
Knowledge Graph (KG) reasoning, which aims to infer new facts from structured knowledge repositories, plays a vital role in Natural Language Processing (NLP) systems. Its effectiveness critically depends on constructing informative and contextually relevant reasoning paths. However, existing graph neural networks (GNNs) often adopt rigid, query-agnostic path-exploration strategies, limiting their ability to adapt to diverse linguistic contexts and semantic nuances. To address these limitations, we propose MoKGR, a mixture-of-experts framework that personalizes path exploration through two complementary components: (1) a mixture of length experts that adaptively selects and weights candidate path lengths according to query complexity, providing query-specific reasoning depth; and (2) a mixture of pruning experts that evaluates candidate paths from a complementary perspective, retaining the most informative paths for each query. Through comprehensive experiments on diverse benchmark, MoKGR demonstrates superior performance in both transductive and inductive settings, validating the effectiveness of personalized path exploration in KGs reasoning.