Zhengzhang Chen
2026
Decoding Time Series with LLMs: A Multi-Agent Framework for Cross-Domain Annotation
Minhua Lin | Zhengzhang Chen | Yanchi Liu | Xujiang Zhao | Zongyu Wu | Junxiang Wang | Xiang Zhang | Suhang Wang | Haifeng Chen
Findings of the Association for Computational Linguistics: EACL 2026
Minhua Lin | Zhengzhang Chen | Yanchi Liu | Xujiang Zhao | Zongyu Wu | Junxiang Wang | Xiang Zhang | Suhang Wang | Haifeng Chen
Findings of the Association for Computational Linguistics: EACL 2026
Time series data is ubiquitous across various domains, including manufacturing, finance, and healthcare. High-quality annotations are essential for effectively understanding time series and facilitating downstream tasks. However, obtaining such annotations is challenging, particularly in mission-critical domains. In this paper, we propose TESSA, a multi-agent system designed to automatically generate both general and domain-specific annotations for time series data. TESSA introduces two agents: a general annotation agent and a domain-specific annotation agent. The general agent captures common patterns and knowledge across multiple source domains, leveraging both time-series-wise and text-wise features to generate general annotations. Meanwhile, the domain-specific agent utilizes limited annotations from the target domain to learn domain-specific terminology and generate targeted annotations. Extensive experiments on multiple synthetic and real-world datasets demonstrate that TESSA effectively generates high-quality annotations, outperforming existing methods.
Multi-Agent Procedural Graph Extraction with Structural and Logical Refinement
Wangyang Ying | Yanchi Liu | Xujiang Zhao | Wei Cheng | Zhengzhang Chen | Wenchao Yu | Yanjie Fu | Haifeng Chen
Findings of the Association for Computational Linguistics: EACL 2026
Wangyang Ying | Yanchi Liu | Xujiang Zhao | Wei Cheng | Zhengzhang Chen | Wenchao Yu | Yanjie Fu | Haifeng Chen
Findings of the Association for Computational Linguistics: EACL 2026
Automatically extracting workflows as procedural graphs from natural language is a promising yet underexplored task that requires ensuring both structural validity and logical alignment. Recent advances in large language models (LLMs) show potential for graph extraction, but often yield ill-formed structures or misinterpret logical constructs such as gateways. We introduce , a multi-agent framework that treats procedural graph extraction as a multi-round reasoning process with structural and logical refinement agents. The framework operates in three iterative stages: (1) an LLM-based graph extraction phase, (2) a structural feedback phase where a simulation agent diagnoses and explains structural issues, and (3) a logical feedback phase where a semantic agent aligns semantics between flow logic and linguistic cues in the source text. Important feedback is prioritized and expressed in natural language, which is injected into the next-round prompt, enabling interpretable and controllable refinement. This modular design allows agents to target distinct error types without supervision or parameter updates. Experiments demonstrate that achieves substantial improvements in both structural correctness and logical consistency over strong baselines.
2025
Exploring Multi-Modal Data with Tool-Augmented LLM Agents for Precise Causal Discovery
ChengAo Shen | Zhengzhang Chen | Dongsheng Luo | Dongkuan Xu | Haifeng Chen | Jingchao Ni
Findings of the Association for Computational Linguistics: ACL 2025
ChengAo Shen | Zhengzhang Chen | Dongsheng Luo | Dongkuan Xu | Haifeng Chen | Jingchao Ni
Findings of the Association for Computational Linguistics: ACL 2025
Causal discovery is an imperative foundation for decision-making across domains, such as smart health, AI for drug discovery and AIOps. Traditional statistical causal discovery methods, while well-established, predominantly rely on observational data and often overlook the semantic cues inherent in cause-and-effect relationships. The advent of Large Language Models (LLMs) has ushered in an affordable way of leveraging the semantic cues for knowledge-driven causal discovery, but the development of LLMs for causal discovery lags behind other areas, particularly in the exploration of multi-modal data. To bridge the gap, we introduce MatMCD, a multi-agent system powered by tool-augmented LLMs. MatMCD has two key agents: a Data Augmentation agent that retrieves and processes modality-augmented data, and a Causal Constraint agent that integrates multi-modal data for knowledge-driven reasoning. The proposed design of the inner-workings ensures successful cooperation of the agents. Our empirical study across seven datasets suggests the significant potential of multi-modality enhanced causal discovery.
MixLLM: Dynamic Routing in Mixed Large Language Models
Xinyuan Wang | Yanchi Liu | Wei Cheng | Xujiang Zhao | Zhengzhang Chen | Wenchao Yu | Yanjie Fu | Haifeng Chen
Proceedings of the 2025 Conference of the Nations of the Americas Chapter of the Association for Computational Linguistics: Human Language Technologies (Volume 1: Long Papers)
Xinyuan Wang | Yanchi Liu | Wei Cheng | Xujiang Zhao | Zhengzhang Chen | Wenchao Yu | Yanjie Fu | Haifeng Chen
Proceedings of the 2025 Conference of the Nations of the Americas Chapter of the Association for Computational Linguistics: Human Language Technologies (Volume 1: Long Papers)
Large Language Models (LLMs) exhibit potential artificial generic intelligence recently, however, their usage is costly with high response latency. Given mixed LLMs with their own strengths and weaknesses, LLM routing aims to identify the most suitable model for each query in the stream to maximize response quality and minimize cost and latency. However, the challenges involve: (1) dynamic trade-offs among quality, cost, and latency; (2) enabling continual learning in deployed systems; and (3) navigating a varying (e.g., new LLM addition or old LLM removal) set of LLM candidates over time. To bridge these gaps, we develop MixLLM, a dynamic contextual-bandit-based routing system for query-LLM assignment. Specifically, we first leverage query tags to enhance query embeddings for the routing task. Next, we design lightweight prediction models to estimate the response qualities and costs of queries over LLMs. We then devise a meta-decision maker to choose the query-LLM assignments to best tradeoff response quality, cost, and latency. Finally, the system benefits from continual training, allowing it to adapt to evolving queries and user feedback over time. Our extensive experiments show that MixLLM achieves the best trade-offs in response quality, cost, and latency (97.25% of GPT-4’s quality at 24.18% of the cost under the time constraint).