Zihao Xu
Author directory2026
Compressing Sequences in the Latent Embedding Space: K-Token Merging for Large Language Models
Zihao Xu | John Harvill | Ziwei Fan | Yizhou Sun | Hao Ding | Hao Wang
Proceedings of the 2026 Conference on Empirical Methods in Natural Language Processing
Zihao Xu | John Harvill | Ziwei Fan | Yizhou Sun | Hao Ding | Hao Wang
Proceedings of the 2026 Conference on Empirical Methods in Natural Language Processing
Large Language Models (LLMs) incur significant computational and memory costs when processing long prompts, as full self-attention scales quadratically with input length. Token compression aims to address this challenge by reducing the number of tokens representing inputs. However, existing prompt-compression approaches primarily operate in token space and overlook inefficiencies in the latent embedding space. In this paper, we propose K-Token Merging, a latent-space compression framework that merges each contiguous block of token embeddings into a single embedding via a lightweight encoder. The compressed sequence is processed by a LoRA-adapted LLM, while generation remains in the original vocabulary. Experiments on structural reasoning (Textualized Tree), sentiment classification (Amazon Reviews), and code editing (CommitPackFT) show that K-Token Merging lies on the Pareto frontier of performance vs. compression, achieving up to 75% input length reduction with minimal performance degradation.
TVIR: Building Deep Research Agents Towards Text-Visual Interleaved Report Generation
Xinkai Ma | Zhiqi Bai | Dingling Zhang | Pei Liu | Yishuo Yuan | He Zhu | Jiakai Wang | Qianqian Xie | Yifan Zhao | Xinlong Yang | Hao Cong | Zhiheng Yao | Fengxia Xie | Zihao Xu | Haoran Xu | Zhaohui Wang | Minghao Liu | Shirong Lin | Yingshui Tan | Yuchi Xu | Wenbo Su | Zhaoxiang Zhang | Bo Zheng | Jiaheng Liu
Proceedings of the 2026 Conference on Empirical Methods in Natural Language Processing
Xinkai Ma | Zhiqi Bai | Dingling Zhang | Pei Liu | Yishuo Yuan | He Zhu | Jiakai Wang | Qianqian Xie | Yifan Zhao | Xinlong Yang | Hao Cong | Zhiheng Yao | Fengxia Xie | Zihao Xu | Haoran Xu | Zhaohui Wang | Minghao Liu | Shirong Lin | Yingshui Tan | Yuchi Xu | Wenbo Su | Zhaoxiang Zhang | Bo Zheng | Jiaheng Liu
Proceedings of the 2026 Conference on Empirical Methods in Natural Language Processing
Deep Research Agents have shown strong capability in multi-step information retrieval, reasoning, and long-form report generation, but existing benchmarks and systems remain predominantly text-centric, with limited evaluation of whether visual elements are factually reliable and well aligned with the surrounding analysis. To address this gap, we introduce TVIR (Text–Visual Interleaved Report Generation), which includes TVIR-Bench, a benchmark of 100 expert-curated multimodal deep research tasks that require visual elements to serve specific analytical sub-goals, and TVIR-Agent, a hierarchical multi-agent framework for constructing structured outlines, retrieving images, generating charts with traceable sources, and composing reports through context-aware sequential writing. We further develop a dual-path evaluation framework that combines Textual Assessment and Visual Assessment. Experiments across nine deep research systems show that TVIR-Agent achieves strong overall performance, underscoring the importance of explicit multimodal design and evaluation for evidence-driven report generation.
2024
A Comprehensive Study of Jailbreak Attack versus Defense for Large Language Models
Zihao Xu | Yi Liu | Gelei Deng | Yuekang Li | Stjepan Picek
Findings of the Association for Computational Linguistics: ACL 2024
Zihao Xu | Yi Liu | Gelei Deng | Yuekang Li | Stjepan Picek
Findings of the Association for Computational Linguistics: ACL 2024
Large Language Models (LLMs) have increasingly become central to generating content with potential societal impacts. Notably, these models have demonstrated capabilities for generating content that could be deemed harmful. To mitigate these risks, researchers have adopted safety training techniques to align model outputs with societal values to curb the generation of malicious content. However, the phenomenon of “jailbreaking” — where carefully crafted prompts elicit harmful responses from models — persists as a significant challenge. This research conducts a comprehensive analysis of existing studies on jailbreaking LLMs and their defense techniques. We meticulously investigate nine attack techniques and seven defense techniques applied across three distinct language models: Vicuna, LLama, and GPT-3.5 Turbo. We aim to evaluate the effectiveness of these attack and defense techniques. Our findings reveal that existing white-box attacks underperform compared to universal techniques and that including special tokens in the input significantly affects the likelihood of successful attacks. This research highlights the need to concentrate on the security facets of LLMs. Additionally, we contribute to the field by releasing our datasets and testing framework, aiming to foster further research into LLM security. We believe these contributions will facilitate the exploration of security measures within this domain.
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Co-authors
- Zhiqi Bai 1
- Hao Cong 1
- Gelei Deng 1
- Hao Ding 1
- Ziwei Fan 1
- John Harvill 1
- Yuekang Li 1
- Shirong Lin 1
- Jiaheng Liu 1
- Minghao Liu 1
- Pei Liu 1
- Yi Liu 1
- Xinkai Ma 1
- Stjepan Picek 1
- Wenbo Su 1
- Yizhou Sun 1
- Yingshui Tan 1
- Hao Wang 1
- Jiakai Wang 1
- Zhaohui Wang 1
- Fengxia Xie 1
- Qianqian Xie 1
- Haoran Xu 1
- Yuchi Xu 1
- Xinlong Yang 1
- Zhiheng Yao 1
- Yishuo Yuan 1
- Dingling Zhang 1
- Zhaoxiang Zhang 1
- Yifan Zhao 1
- Bo Zheng 1
- He Zhu 1