Demo Data from SIGIR 2026 / reviewers in the wild / expert
Chengjin Xu
dblp:247/6268
· DBLP profile ↗
33ranked-venue papers
7as first author
30since 2021 · last 2026
0000-0002-4942-9049ORCID · corroborated
Domains — the database's venue-derived domains; a paper can count in several
Artificial intelligence and machine learning · 22 · 5 first-author · 20 since 2021Databases, data management, data science and information retrieval · 12 · 2 first-author · 11 since 2021Graphics, computer vision, multimedia, augmented reality and games · 5 · 5 since 2021Applied, interdisciplinary, general and emerging computing · 4 · 1 first-author · 4 since 2021
Expertise — from the expertise taxonomy: the topics of the expert's papers under the CCF categories. A weight counts papers with recency: 1 for a paper about the topic, 0.3 when the topic is its context, halved every five years.
| Databases, data mining, and information retrieval
14 papers |
Knowledge graphs · 76% Data mining · 11% Data models and query languages · 5% | |
| Artificial intelligence
16 papers |
Knowledge representation and reasoning · 28% Vision and language · 25% Language models and text generation · 23% |
Topics — the 30 heaviest of 40, each with the papers that count most for it
| Topic | Weight | Papers | Last | Evidence papers |
|---|---|---|---|---|
Knowledge graphs › knowledge graph alignment
entity alignment |
3.2 | 5 | 2024 | Toward Practical Entity Alignment Method Design: Insights from New Highly Heterogeneous Knowledge Graph Datasets · WWW 2024 Unlocking the Power of Large Language Models for Entity Alignment · ACL (1) 2024 Cross-Modal Graph Attention Network for Entity Alignment · ACM Multimedia 2023 |
Natural language and speech › Language models and text generation
retrieval-augmented generation |
1.9 | 2 | 2026 | Financial Wind Tunnel: A Retrieval-Augmented Market Simulator · WWW 2026 Think-on-Graph 2.0: Deep and Faithful Large Language Model Reasoning with Knowledge-guided Retrieval Augmented Generation · ICLR 2025 |
Knowledge graphs
knowledge graph embedding |
1.8 | 3 | 2023 | Geometric Algebra Based Embeddings for Static and Temporal Knowledge Graph Completion · IEEE Trans. Knowl. Data Eng. 2023 Time-aware Entity Alignment using Temporal Relational Attention · WWW 2022 Ultrahyperbolic Knowledge Graph Embeddings · KDD 2022 |
Computer vision › Vision and language › vision-language model › multimodal large language model
chart understanding |
1.7 | 2 | 2025 | ChartMoE: Mixture of Diversely Aligned Expert Connector for Chart Understanding · ICLR 2025 ChartPoint: Guiding MLLMs with Grounding Reflection for Chart Reasoning · ICCV 2025 |
Knowledge graphs
link prediction |
1.5 | 2 | 2025 | Context-aware Inductive Knowledge Graph Completion with Latent Type Constraints and Subgraph Reasoning · AAAI 2025 Geometric Algebra Based Embeddings for Static and Temporal Knowledge Graph Completion · IEEE Trans. Knowl. Data Eng. 2023 |
Knowledge graphs
temporal knowledge graph |
1.3 | 2 | 2023 | Meta-Learning Based Knowledge Extrapolation for Temporal Knowledge Graph · WWW 2023 TFLEX: Temporal Feature-Logic Embedding Framework for Complex Reasoning over Temporal Knowledge Graph · NeurIPS 2023 |
Knowledge graphs › link prediction
temporal knowledge graph completion |
1.3 | 2 | 2023 | Geometric Algebra Based Embeddings for Static and Temporal Knowledge Graph Completion · IEEE Trans. Knowl. Data Eng. 2023 Incorporating Structured Sentences with Time-enhanced BERT for Fully-inductive Temporal Relation Prediction · SIGIR 2023 |
Knowledge, reasoning and agents › Knowledge representation and reasoning › knowledge graph
knowledge graph embedding |
1.2 | 2 | 2023 | LogicENN: A Neural Based Knowledge Graphs Embedding Model With Logical Rules · IEEE Trans. Pattern Anal. Mach. Intell. 2023 Knowledge Graph Representation Learning using Ordinary Differential Equations · EMNLP (1) 2021 |
Knowledge graphs › knowledge graph alignment › entity alignment
temporal knowledge graph entity alignment |
1.1 | 2 | 2022 | Time-aware Entity Alignment using Temporal Relational Attention · WWW 2022 Time-aware Graph Neural Network for Entity Alignment between Temporal Knowledge Graphs · EMNLP (1) 2021 |
Natural language and speech › Language models and text generation
large language model reasoning |
1.0 | 2 | 2025 | Think-on-Graph: Deep and Responsible Reasoning of Large Language Model on Knowledge Graph · ICLR 2024 Context-aware Inductive Knowledge Graph Completion with Latent Type Constraints and Subgraph Reasoning · AAAI 2025 |
Computational finance and economics › financial modeling
market simulation |
1.0 | 1 | 2026 | Financial Wind Tunnel: A Retrieval-Augmented Market Simulator · WWW 2026 |
Data mining
anomaly detection |
1.0 | 1 | 2026 | BAG: Benchmarking Anomaly Detection on Dynamic Graphs · AAAI 2026 |
Data mining › anomaly detection › graph anomaly detection
dynamic graph anomaly detection |
1.0 | 1 | 2026 | BAG: Benchmarking Anomaly Detection on Dynamic Graphs · AAAI 2026 |
Computer vision › Vision and language › multimodal reasoning
chart reasoning |
0.9 | 1 | 2025 | ChartPoint: Guiding MLLMs with Grounding Reflection for Chart Reasoning · ICCV 2025 |
Natural language and speech › Question answering and dialogue systems
knowledge-intensive question answering |
0.9 | 1 | 2025 | Think-on-Graph 2.0: Deep and Faithful Large Language Model Reasoning with Knowledge-guided Retrieval Augmented Generation · ICLR 2025 |
Machine learning › Deep learning architectures and training
mixture of experts |
0.9 | 1 | 2025 | ChartMoE: Mixture of Diversely Aligned Expert Connector for Chart Understanding · ICLR 2025 |
Computer vision › Vision and language › vision-language model
multimodal large language model |
0.9 | 1 | 2025 | ChartPoint: Guiding MLLMs with Grounding Reflection for Chart Reasoning · ICCV 2025 |
Natural language and speech › Language models and text generation › large language model reasoning
reasoning model training |
0.9 | 1 | 2025 | SQL-R1: Training Natural Language to SQL Reasoning Model By Reinforcement Learning · NeurIPS 2025 |
Computer vision › Vision and language
visual grounding |
0.9 | 1 | 2025 | ChartPoint: Guiding MLLMs with Grounding Reflection for Chart Reasoning · ICCV 2025 |
Knowledge graphs › link prediction
inductive link prediction |
0.9 | 1 | 2025 | Context-aware Inductive Knowledge Graph Completion with Latent Type Constraints and Subgraph Reasoning · AAAI 2025 |
Knowledge graphs
knowledge graph reasoning |
0.9 | 1 | 2025 | Think-on-Graph 2.0: Deep and Faithful Large Language Model Reasoning with Knowledge-guided Retrieval Augmented Generation · ICLR 2025 |
Data models and query languages › natural language interface › natural language interface to database
text-to-SQL |
0.9 | 1 | 2025 | SQL-R1: Training Natural Language to SQL Reasoning Model By Reinforcement Learning · NeurIPS 2025 |
Knowledge, reasoning and agents › Knowledge representation and reasoning
knowledge graph reasoning |
0.8 | 1 | 2024 | Think-on-Graph: Deep and Responsible Reasoning of Large Language Model on Knowledge Graph · ICLR 2024 |
Graph data management › heterogeneous graph
heterogeneous knowledge graph |
0.8 | 1 | 2024 | Toward Practical Entity Alignment Method Design: Insights from New Highly Heterogeneous Knowledge Graph Datasets · WWW 2024 |
Machine learning › Graph learning
graph neural network |
0.7 | 2 | 2022 | Time-aware Graph Neural Network for Entity Alignment between Temporal Knowledge Graphs · EMNLP (1) 2021 Time-aware Entity Alignment using Temporal Relational Attention · WWW 2022 |
Machine learning › Graph learning › graph neural network › attention-based graph neural network
graph attention network |
0.7 | 1 | 2023 | Cross-Modal Graph Attention Network for Entity Alignment · ACM Multimedia 2023 |
Knowledge graphs › temporal knowledge graph
knowledge graph extrapolation |
0.7 | 1 | 2023 | Meta-Learning Based Knowledge Extrapolation for Temporal Knowledge Graph · WWW 2023 |
Knowledge graphs › knowledge graph alignment › entity alignment
multi-modal entity alignment |
0.7 | 1 | 2023 | Cross-Modal Graph Attention Network for Entity Alignment · ACM Multimedia 2023 |
Information retrieval
pre-trained language model |
0.7 | 1 | 2023 | Incorporating Structured Sentences with Time-enhanced BERT for Fully-inductive Temporal Relation Prediction · SIGIR 2023 |
Knowledge graphs › knowledge graph embedding
hyperbolic embedding |
0.6 | 1 | 2022 | Ultrahyperbolic Knowledge Graph Embeddings · KDD 2022 |
Methods — techniques the papers use, named apart from their topics
graph neural network · 3.6supervised fine-tuning · 3.5attention mechanism · 2.1benchmarking · 2.0subgraph reasoning · 1.7prompt engineering · 1.7instruction tuning · 1.7evaluation protocols · 1.0evaluation protocol · 1.0reinforcement learning · 0.9multimodal large language model · 0.9knowledge-guided retrieval · 0.9iterative retrieval · 0.9chain-of-thought prompting · 0.9
| Year | Publication | Venue | Position |
|---|---|---|---|
| 2026 | BAG: Benchmarking Anomaly Detection on Dynamic GraphsabstractAnomaly detection in dynamic graphs is a critical area of research that focuses on identifying abnormal components within evolving graph structures that deviate significantly from typical patterns. Despite advancements in traditional temporal pattern mining and deep learning techniques, a comprehensive benchmarking framework for Dynamic Graph Anomaly Detection (DyGAD) has been lacking. To address this gap, we introduce BAG, the first comprehensive benchmark specifically designed for anomaly detection on dynamic graphs. BAG enables extensive evaluation of 25 leading DyGAD models, covering both classical approaches and advanced Dynamic Graph Neural Networks (DGNNs), across 10 diverse real-world datasets that include both synthetic and naturally occurring anomalies. The framework supports evaluations at both the edge and node levels, offering a robust tool to advance DyGAD research. Our main finding is that Continuous-time Dynamic Graph (CTDG) models demonstrate superior performance and potential in detecting anomalies in dynamic graph edges, compared to Discrete-time Dynamic Graph (DTDG) models. Furthermore, the results reveal that existing methods are less effective at detecting organic anomalies, primarily due to the presence of temporal anomalies and highly imbalanced samples. The proposed BAG benchmark significantly enhances the evaluation of DyGAD methods by improving dataset selection, metric application, and model training. Moreover, BAG supports reproducibility and further exploration in this field by integrating all models, datasets, and evaluation protocols into an open-source repository. Fengrui Hua, Yiyan Qi, Zikai Wei, Yuxing Tian, Chengjin Xu, Xiaojun Wu 0007, Jia Li 0009, Jian Guo 0016 |
AAAI | 5 |
| 2026 | Financial Wind Tunnel: A Retrieval-Augmented Market Simulator
Bokai Cao, Xueyuan Lin, Yiyan Qi, Chengjin Xu, Cehao Yang, Jian Guo 0016 |
WWW | 4 |
| 2025 | Context-aware Inductive Knowledge Graph Completion with Latent Type Constraints and Subgraph ReasoningabstractInductive knowledge graph completion (KGC) aims to predict missing triples with unseen entities. Recent works focus on modeling reasoning paths between the head and tail entity as direct supporting evidence. However, these methods depend heavily on the existence and quality of reasoning paths, which limits their general applicability in different scenarios. In addition, we observe that latent type constraints and neighboring facts inherent in KGs are also vital in inferring missing triples. To effectively utilize all useful information in KGs, we introduce CATS, a novel context-aware inductive KGC solution. With sufficient guidance from proper prompts and supervised fine-tuning, CATS activates the strong semantic understanding and reasoning capabilities of large language models to assess the existence of query triples, which consist of two modules. First, the type-aware reasoning module evaluates whether the candidate entity matches the latent entity type as required by the query relation. Then, the subgraph reasoning module selects relevant reasoning paths and neighboring facts, and evaluates their correlation to the query triple. Experiment results on three widely used datasets demonstrate that CATS significantly outperforms state-of-the-art methods in 16 out of 18 transductive, inductive, and few-shot settings with an average absolute MRR improvement of 7.2%. Muzhi Li 0001, Cehao Yang, Chengjin Xu, Zixing Song, Xuhui Jiang, Jian Guo 0016, Ho-fung Leung, Irwin King |
AAAI | 3 |
| 2025 | ChartPoint: Guiding MLLMs with Grounding Reflection for Chart ReasoningabstractMultimodal Large Language Models (MLLMs) have emerged as powerful tools for chart comprehension. However, they heavily rely on extracted content via OCR, which leads to numerical hallucinations when chart textual annotations are sparse. While existing methods focus on scaling instructions, they fail to address the fundamental challenge, i.e., reasoning with visual perception. In this paper, we identify a critical observation: MLLMs exhibit weak grounding in chart elements and proportional relationships, as evidenced by their inability to localize key positions to match their reasoning. To bridge this gap, we propose PointCoT, which integrates reflective interaction into chain-of-thought reasoning in charts. By prompting MLLMs to generate bounding boxes and re-render charts based on location annotations, we establish connections between textual reasoning steps and visual grounding regions. We further introduce an automated pipeline to construct ChartPoint-SFT-62k, a dataset featuring 19.2K high-quality chart samples with step-by-step CoT, bounding box, and re-rendered visualizations. Leveraging this data, we develop two instruction-tuned models, ChartPointQ2 and ChartPointQ2.5, which outperform state-of-the-art across several chart benchmarks, e.g., +5.04\% on ChartBench. Zhengzhuo Xu, SiNan Du, Yiyan Qi, Siwen Lu, Chengjin Xu, Chun Yuan 0003 |
ICCV | 5 |
| 2025 | Think-on-Graph 2.0: Deep and Faithful Large Language Model Reasoning with Knowledge-guided Retrieval Augmented GenerationabstractRetrieval-augmented generation (RAG) has improved large language models (LLMs) by using knowledge retrieval to overcome knowledge deficiencies. However, current RAG methods often fall short of ensuring the depth and completeness of retrieved information, which is necessary for complex reasoning tasks. In this work, we introduce Think-on-Graph 2.0 (ToG-2), a hybrid RAG framework that iteratively retrieves information from both unstructured and structured knowledge sources in a tight-coupling manner. Specifically, ToG-2 leverages knowledge graphs (KGs) to link documents via entities, facilitating deep and knowledge-guided context retrieval. Simultaneously, it utilizes documents as entity contexts to achieve precise and efficient graph retrieval.
ToG-2 alternates between graph retrieval and context retrieval to search for in-depth clues relevant to the question, enabling LLMs to generate answers.
We conduct a series of well-designed experiments to highlight the following advantages of ToG-2: 1) ToG-2 tightly couples the processes of context retrieval and graph retrieval, deepening context retrieval via the KG while enabling reliable graph retrieval based on contexts; 2) it achieves deep and faithful reasoning in LLMs through an iterative knowledge retrieval process of collaboration between contexts and the KG; and 3) ToG-2 is training-free and plug-and-play compatible with various LLMs. Extensive experiments demonstrate that ToG-2 achieves overall state-of-the-art (SOTA) performance on 6 out of 7 knowledge-intensive datasets with GPT-3.5, and can elevate the performance of smaller models (e.g., LLAMA-2-13B) to the level of GPT-3.5’s direct reasoning. The source code is available on https://anonymous.4open.science/r/ToG2. Shengjie Ma, Chengjin Xu, Xuhui Jiang, Muzhi Li 0001, Huaren Qu, Cehao Yang, Jiaxin Mao, Jian Guo 0016 |
ICLR | 2 |
| 2025 | ChartMoE: Mixture of Diversely Aligned Expert Connector for Chart UnderstandingabstractAutomatic chart understanding is crucial for content comprehension and document parsing. Multimodal Large Language Models (MLLMs) have demonstrated remarkable capabilities in chart understanding through domain-specific alignment and fine-tuning. However, current MLLMs still struggle to provide faithful data and reliable analysis only based on charts. To address it, we propose ChartMoE, which employs the Mixture of Expert (MoE) architecture to replace the traditional linear projector to bridge the modality gap. Specifically, we train several linear connectors through distinct alignment tasks, which are utilized as the foundational initialization parameters for different experts. Additionally, we introduce ChartMoE-Align, a dataset with nearly 1 million chart-table-JSON-code quadruples to conduct three alignment tasks (chart-table/JSON/code). Combined with the vanilla connector, we initialize different experts diversely and adopt high-quality knowledge learning to further refine the MoE connector and LLM parameters. Extensive experiments demonstrate the effectiveness of the MoE connector and our initialization strategy, e.g., ChartMoE improves the accuracy of the previous state-of-the-art from 80.48% to 84.64% on the ChartQA benchmark. Zhengzhuo Xu, Bowen Qu, Yiyan Qi, Sinan Du, Chengjin Xu, Chun Yuan 0003 |
ICLR | 5 |
| 2025 | Retrieval, Reasoning, Re-ranking: A Context-Enriched Framework for Knowledge Graph CompletionabstractMuzhi Li, Cehao Yang, Chengjin Xu, Xuhui Jiang, Yiyan Qi, Jian Guo, Ho-fung Leung, Irwin King. 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). 2025. Muzhi Li 0001, Cehao Yang, Chengjin Xu, Xuhui Jiang, Yiyan Qi, Jian Guo 0016, Ho-fung Leung, Irwin King |
NAACL (Long Papers) | 3 |
| 2025 | SQL-R1: Training Natural Language to SQL Reasoning Model By Reinforcement LearningabstractNatural Language to SQL (NL2SQL) enables intuitive interactions with databases by transforming natural language queries into structured SQL statements. Despite recent advancements in enhancing human-computer interaction within database applications, significant challenges persist, particularly regarding the inference performance in complex scenarios involving multi-table joins and nested queries. Current methodologies primarily utilize supervised fine-tuning (SFT) to train the NL2SQL model, which may limit adaptability and interpretability in new environments (e.g., finance and healthcare).
In order to enhance the reasoning performance of the NL2SQL model in the above complex situations, we introduce SQL-R1, a novel NL2SQL reasoning model trained by the reinforcement learning (RL) algorithms.
We design a specialized RL-based reward function tailored for NL2SQL tasks and discussed the impact of cold start and synthetic data on the effectiveness of intensive training. In addition, we achieve competitive accuracy using only a tiny amount of synthetic NL2SQL data for augmented training and further explore data engineering for RL. In existing experiments, SQL-R1 achieves execution accuracy of 88.6\% and 67.1\% on the benchmark Spider and BIRD, respectively. The code is available at https://github.com/IDEA-FinAI/SQL-R1. Peixian Ma, Xialie Zhuang, Chengjin Xu, Xuhui Jiang, Jian Guo 0016 |
NeurIPS | 3 |
| 2024 | Unlocking the Power of Large Language Models for Entity AlignmentabstractXuhui Jiang, Yinghan Shen, Zhichao Shi, Chengjin Xu, Wei Li, Zixuan Li, Jian Guo, Huawei Shen, Yuanzhuo Wang. Proceedings of the 62nd Annual Meeting of the Association for Computational Linguistics (Volume 1: Long Papers). 2024. Xuhui Jiang, Yinghan Shen, Zhichao Shi 0001, Chengjin Xu, Wei Li 0176, Zixuan Li 0001, Jian Guo 0016, Huawei Shen, Yuanzhuo Wang |
ACL (1) | 4 |
| 2024 | Think-on-Graph: Deep and Responsible Reasoning of Large Language Model on Knowledge GraphabstractAlthough large language models (LLMs) have achieved significant success in various tasks, they often struggle with hallucination problems, especially in scenarios requiring deep and responsible reasoning. These issues could be partially addressed by introducing external knowledge graphs (KG) in LLM reasoning. In this paper, we propose a new LLM-KG integrating paradigm ``$\hbox{LLM}\otimes\hbox{KG}$'' which treats the LLM as an agent to interactively explore related entities and relations on KGs and perform reasoning based on the retrieved knowledge. We further implement this paradigm by introducing a new approach called Think-on-Graph (ToG), in which the LLM agent iteratively executes beam search on KG, discovers the most promising reasoning paths, and returns the most likely reasoning results. We use a number of well-designed experiments to examine and illustrate the following advantages of ToG: 1) compared with LLMs, ToG has better deep reasoning power; 2) ToG has the ability of knowledge traceability and knowledge correctability by leveraging LLMs reasoning and expert feedback; 3) ToG provides a flexible plug-and-play framework for different LLMs, KGs and prompting strategies without any additional training cost; 4) the performance of ToG with small LLM models could exceed large LLM such as GPT-4 in certain scenarios and this reduces the cost of LLM deployment and application. As a training-free method with lower computational cost and better generality, ToG achieves overall SOTA in 6 out of 9 datasets where most previous SOTAs rely on additional training. Jiashuo Sun, Chengjin Xu, Lumingyuan Tang, Saizhuo Wang, Chen Lin 0001, Yeyun Gong, Lionel M. Ni, Harry Shum, Jian Guo 0016 |
ICLR | 2 |
| 2024 | Ensuring Safe and High-Quality Outputs: A Guideline Library Approach for Language ModelsabstractYi Luo, Zhenghao Lin, YuHao Zhang, Jiashuo Sun, Chen Lin, Chengjin Xu, Xiangdong Su, Yelong Shen, Jian Guo, Yeyun Gong. Proceedings of the 2024 Conference of the North American Chapter of the Association for Computational Linguistics: Human Language Technologies (Volume 1: Long Papers). 2024. Zhenghao Lin, Jiashuo Sun, Chen Lin 0001, Chengjin Xu, Xiangdong Su, Yelong Shen, Jian Guo 0016, Yeyun Gong |
NAACL-HLT | 6 |
| 2024 | Toward Practical Entity Alignment Method Design: Insights from New Highly Heterogeneous Knowledge Graph DatasetsabstractThe flourishing of knowledge graph (KG) applications has driven the need for entity alignment (EA) across KGs. However, the heterogeneity of practical KGs, characterized by differing scales, structures, and limited overlapping entities, greatly surpasses that of existing EA datasets. This discrepancy highlights an oversimplified heterogeneity in current EA datasets, which obstructs the exploration of the EA application. In this paper, we study the performance of EA methods on the alignment of highly heterogeneous KGs (HHKGs). Firstly, we address the oversimplified heterogeneity settings of current datasets and propose two new HHKG datasets that closely mimic practical EA scenarios. Then, based on these datasets, we conduct extensive experiments to evaluate previous representative EA methods. Our findings reveal that, in aligning HHKGs, valuable structure information can hardly be exploited, which leads to inferior performance of existing EA methods, especially those based on GNNs. These findings shed light on the potential problems associated with the conventional application of GNN-based methods as a panacea for all EA datasets. Consequently, to elucidate what EA methodology is genuinely beneficial in practical scenarios, we undertake an in-depth analysis by implementing a simple but effective approach: Simple-HHEA. Our experiment results conclude that the key to the future EA model design in practice lies in their adaptability and efficiency to varying information quality conditions, as well as their capability to capture patterns across HHKGs. The datasets and source code are available at https://github.com/IDEA-FinAI/Simple-HHEA. Xuhui Jiang, Chengjin Xu, Yinghan Shen, Yuanzhuo Wang, Fenglong Su, Zhichao Shi 0001, Fei Sun 0001, Zixuan Li 0001, Jian Guo 0016, Huawei Shen |
WWW | 2 |
| 2023 | Meta-Path Based Social Relation Reasoning in a Deep and Robust Way
Xuhui Jiang, Yinghan Shen, Yuanzhuo Wang, Huawei Shen, Chengjin Xu, Shengjie Ma |
DASFAA (3) | 5 |
| 2023 | Task-Sensitive Discriminative Mutual Attention Network for Few-Shot LearningabstractMany few-shot image classification methods focus on learning a fixed feature space from sufficient samples of seen classes that can be readily transferred to unseen classes. For different tasks, the feature space is either kept the same or only adjusted by generating attentions to query samples. However, the discriminative channels and spatial parts for comparing different query and support images in different tasks are usually different. In this paper, we propose a task-sensitive discriminative mutual attention (TDMA) network to produce task-and-sample-specific features. For each task, TDMA first generates a discriminative task embedding that encodes the inter-class separability and within-class scatter, and then employs the task embedding to enhance discriminative channels respective to this task. Given a specific query and different support images, TDMA further incorporates the task embedding and long-range dependencies to locate the discriminative parts in the spatial dimension. Experimental results on miniImageNet, tieredImageNet and FC100 datasets show the effectiveness of the proposed model. Baogui Xu, Chengjin Xu, Zhiwu Lu 0001, Bing Su 0001 |
ECAI | 2 |
| 2023 | Cross-Modal Graph Attention Network for Entity AlignmentabstractThe increasing popularity of multi-modal knowledge graphs (MMKGs) has led to a need for efficient entity alignment techniques that can exploit multi-modal information to integrate knowledge from different sources. GNN-based multi-modal entity alignment (MMEA) methods have achieved significant progress in entity alignment(EA) areas. However, these methods only rely on Graph Neural Networks (GNNs) to encode structural information, while ignoring visual and semantic modalities, which may lead to incomplete representation, thus how to integrate the visual and semantic information into GNN-based EA methods remains unexplored. In light of our insight that incorporating the message-passing mechanism of Graph Neural Networks to integrate multi-modal information is essential for fully exploiting the graph representation capability of GNN, we propose a novel Cross-modal Graph attention network for Entity Alignment (XGEA) that enables visual knowledge to interact with other views of the entity, including structural and literal information. We leverage the information from one modality as complementary relation information to compute the attention of another modality in the graph attention layers, enabling the learning of entity embedding by integrating multiple modalities. Moreover, the quantity of labeled data plays a crucial role in model performance, yet obtaining sufficient training data is expensive. To mitigate this issue, we use visual and semantic information to generate pseudo-pairs and propose a soft pseudo-labeling method for entity alignment to assign weights to the augmented training data to balance its quantity and quality. Extensive experiments show that our XGEA achieves superior performance consistently over the state-of-the-art MMEA baselines. Baogui Xu, Chengjin Xu, Bing Su 0001 |
ACM Multimedia | 2 |
| 2023 | TFLEX: Temporal Feature-Logic Embedding Framework for Complex Reasoning over Temporal Knowledge GraphabstractMulti-hop logical reasoning over knowledge graph plays a fundamental role in many artificial intelligence tasks. Recent complex query embedding methods for reasoning focus on static KGs, while temporal knowledge graphs have not been fully explored. Reasoning over TKGs has two challenges: 1. The query should answer entities or timestamps; 2. The operators should consider both set logic on entity set and temporal logic on timestamp set.
To bridge this gap, we introduce the multi-hop logical reasoning problem on TKGs and then propose the first temporal complex query embedding named Temporal Feature-Logic Embedding framework (TFLEX) to answer the temporal complex queries. Specifically, we utilize fuzzy logic to compute the logic part of the Temporal Feature-Logic embedding, thus naturally modeling all first-order logic operations on the entity set. In addition, we further extend fuzzy logic on timestamp set to cope with three extra temporal operators (**After**, **Before** and **Between**).
Experiments on numerous query patterns demonstrate the effectiveness of our method. Xueyuan Lin, Haihong E, Chengjin Xu, Gengxian Zhou, Haoran Luo 0001, Fenglong Su, Ningyuan Li 0002, Mingzhi Sun |
NeurIPS | 3 |
| 2023 | Distinct Geometrical Representations for Temporal and Relational Structures in Knowledge Graphs
Chengjin Xu, Kossi Amouzouvi, Maocai Wang, Jens Lehmann 0001, Sahar Vahdati |
ECML/PKDD (3) | 2 |
| 2023 | Incorporating Structured Sentences with Time-enhanced BERT for Fully-inductive Temporal Relation PredictionabstractTemporal relation prediction in incomplete temporal knowledge graphs (TKGs) is a popular temporal knowledge graph completion (TKGC) problem in both transductive and inductive settings. Traditional embedding-based TKGC models (TKGE) rely on structured connections and can only handle a fixed set of entities, i.e., the transductive setting. In the inductive setting where test TKGs contain emerging entities, the latest methods are based on symbolic rules or pre-trained language models (PLMs). However, they suffer from being inflexible and not time-specific, respectively. In this work, we extend the fully-inductive setting, where entities in the training and test sets are totally disjoint, into TKGs and take a further step towards a more flexible and time-sensitive temporal relation prediction approach SST-BERT,incorporating Structured Sentences with Time-enhanced BERT. Our model can obtain the entity history and implicitly learn rules in the semantic space by encoding structured sentences, solving the problem of inflexibility. We propose to use a time masking MLM task to pre-train BERT in a corpus rich in temporal tokens specially generated for TKGs, enhancing the time sensitivity of SST-BERT. To compute the probability of occurrence of a target quadruple, we aggregate all its structured sentences from both temporal and semantic perspectives into a score. Experiments on the transductive datasets and newly generated fully-inductive benchmarks show that SST-BERT successfully improves over state-of-the-art baselines. Zhongwu Chen, Chengjin Xu, Fenglong Su, Zhen Huang 0006, Yong Dou |
SIGIR | 2 |
| 2023 | Meta-Learning Based Knowledge Extrapolation for Temporal Knowledge GraphabstractIn the last few years, the solution to Knowledge Graph (KG) completion via learning embeddings of entities and relations has attracted a surge of interest. Temporal KGs(TKGs) extend traditional Knowledge Graphs (KGs) by associating static triples with timestamps forming quadruples. Different from KGs and TKGs in the transductive setting, constantly emerging entities and relations in incomplete TKGs create demand to predict missing facts with unseen components, which is the extrapolation setting. Traditional temporal knowledge graph embedding (TKGE) methods are limited in the extrapolation setting since they are trained within a fixed set of components. In this paper, we propose a Meta-Learning based Temporal Knowledge Graph Extrapolation (MTKGE) model, which is trained on link prediction tasks sampled from the existing TKGs and tested in the emerging TKGs with unseen entities and relations. Specifically, we meta-train a GNN framework that captures relative position patterns and temporal sequence patterns between relations. The learned embeddings of patterns can be transferred to embed unseen components. Experimental results on two different TKG extrapolation datasets show that MTKGE consistently outperforms both the existing state-of-the-art models for knowledge graph extrapolation and specifically adapted KGE and TKGE baselines. Zhongwu Chen, Chengjin Xu, Fenglong Su, Zhen Huang 0006, Yong Dou |
WWW | 2 |
| 2023 | Neural entity alignment with cross-modal supervision
Fenglong Su, Chengjin Xu, Zhongwu Chen, Ning Jing |
Inf. Process. Manag. | 2 |
| 2023 | UniSKGRep: A unified representation learning framework of social network and knowledge graph
Yinghan Shen, Xuhui Jiang, Zijian Li 0014, Yuanzhuo Wang, Chengjin Xu, Huawei Shen, Xueqi Cheng 0001 |
Neural Networks | 5 |
| 2023 | LogicENN: A Neural Based Knowledge Graphs Embedding Model With Logical RulesabstractKnowledge graph embedding models have gained significant attention in AI research. The aim of knowledge graph embedding is to embed the graphs into a vector space in which the structure of the graph is preserved. Recent works have shown that the inclusion of background knowledge, such as logical rules, can improve the performance of embeddings in downstream machine learning tasks. However, so far, most existing models do not allow the inclusion of rules. We address the challenge of including rules and present a new neural based embedding model (LogicENN). We prove that LogicENN can learn every ground truth of encoded rules in a knowledge graph. To the best of our knowledge, this has not been proved so far for the neural based family of embedding models. Moreover, we derive formulae for the inclusion of various rules, including (anti-)symmetric, inverse, irreflexive and transitive, implication, composition, equivalence and negation. Our formulation allows to avoid grounding for implication and equivalence relations. Our experiments show that LogicENN outperforms the existing models in link prediction. Mojtaba Nayyeri, Chengjin Xu, Mirza Mohtashim Alam, Jens Lehmann 0001, Hamed Shariat Yazdi |
IEEE Trans. Pattern Anal. Mach. Intell. | 2 |
| 2023 | Geometric Algebra Based Embeddings for Static and Temporal Knowledge Graph CompletionabstractRecent years, Knowledge Graph Embeddings (KGEs) have shown promising performance on link prediction tasks by mapping the entities and relations from a Knowledge Graph (KG) into a geometric space and thus have gained increasing attentions. In addition, many recent Knowledge Graphs involve evolving data, e.g., the fact (Obama, PresidentOf, USA) is valid only from 2009 to 2017. This introduces important challenges for knowledge representation learning since such temporal KGs change over time. In this work, we strive to move beyond the complex or hypercomplex space for KGE and propose a novel geometric algebra based embedding approach, GeomE, which uses multivector representations and the geometric product to model entities and relations. GeomE subsumes several state-of-the-art KGE models and is able to model diverse relations patterns. On top of this, we extend GeomE to TGeomE for temporal KGE, which performs 4th-order tensor factorization of a temporal KG and devises a new linear temporal regularization for time representation learning. Moreover, we study the effect of time granularity on the performance of TGeomE models. Experimental results show that our proposed models achieve the state-of-the-art performances on link prediction over four commonly-used static KG datasets and four well-established temporal KG datasets across various metrics. Chengjin Xu, Mojtaba Nayyeri, Yung-Yu Chen, Jens Lehmann 0001 |
IEEE Trans. Knowl. Data Eng. | 1 |
| 2022 | Ultrahyperbolic Knowledge Graph EmbeddingsabstractRecent knowledge graph (KG) embeddings have been advanced by hyperbolic geometry due to its superior capability for representing hierarchies. The topological structures of real-world KGs, however, are rather heterogeneous, i.e., a KG is composed of multiple distinct hierarchies and non-hierarchical graph structures. Therefore, a homogeneous (either Euclidean or hyperbolic) geometry is not sufficient for fairly representing such heterogeneous structures. To capture the topological heterogeneity of KGs, we present an ultrahyperbolic KG embedding (UltraE) in an ultrahyperbolic (or pseudo-Riemannian) manifold that seamlessly interleaves hyperbolic and spherical manifolds. In particular, we model each relation as a pseudo-orthogonal transformation that preserves the pseudo-Riemannian bilinear form. The pseudo-orthogonal transformation is decomposed into various operators (i.e., circular rotations, reflections and hyperbolic rotations), allowing for simultaneously modeling heterogeneous structures as well as complex relational patterns. Experimental results on three standard KGs show that UltraE outperforms previous Euclidean, hyperbolic, and mixed-curvature KG embedding approaches. Bo Xiong 0001, Mojtaba Nayyeri, Chengjin Xu, Shirui Pan, Chuan Zhou 0001, Steffen Staab |
KDD | 4 |
| 2022 | Time-aware Entity Alignment using Temporal Relational AttentionabstractKnowledge graph (KG) alignment is to match entities in different KGs, which is important to knowledge fusion and integration. Temporal KGs (TKGs) extend traditional Knowledge Graphs (KGs) by associating static triples with specific timestamps (e.g., temporal scopes or time points). Moreover, open-world KGs (OKGs) are dynamic with new emerging entities and timestamps. While entity alignment (EA) between KGs has drawn increasing attention from the research community, EA between TKGs and OKGs still remains unexplored. In this work, we propose a novel Temporal Relational Entity Alignment method (TREA) which is able to learn alignment-oriented TKG embeddings and represent new emerging entities. We first map entities, relations and timestamps into an embedding space, and the initial feature of each entity is represented by fusing the embeddings of its connected relations and timestamps as well as its neighboring entities. A graph neural network (GNN) is employed to capture intra-graph information and a temporal relational attention mechanism is utilized to integrate relation and time features of links between nodes. Finally, a margin-based full multi-class log-loss is used for efficient training and a sequential time regularizer is used to model unobserved timestamps. We use three well-established TKG datasets, as references for evaluating temporal and non-temporal EA methods. Experimental results show that our method outperforms the state-of-the-art EA methods. Chengjin Xu, Fenglong Su, Bo Xiong 0001, Jens Lehmann 0001 |
WWW | 1 |
| 2021 | Knowledge Graph Representation Learning using Ordinary Differential EquationsabstractKnowledge Graph Embeddings (KGEs) have shown promising performance on link prediction tasks by mapping the entities and relations from a knowledge graph into a geometric space.The capability of KGEs in preserving graph characteristics including structural aspects and semantics, highly depends on the design of their score function, as well as the inherited abilities from the underlying geometry.Many KGEs use the Euclidean geometry which renders them incapable of preserving complex structures and consequently causes wrong inferences by the models.To address this problem, we propose a neuro differential KGE that embeds nodes of a KG on the trajectories of Ordinary Differential Equations (ODEs).To this end, we represent each relation (edge) in a KG as a vector field on several manifolds.We specifically parameterize ODEs by a neural network to represent complex manifolds and complex vector fields on the manifolds.Therefore, the underlying embedding space is capable to assume the shape of various geometric forms to encode heterogeneous subgraphs.Experiments on synthetic and benchmark datasets using state-of-the-art KGE models justify the ODE trajectories as a means to enable structure preservation and consequently avoiding wrong inferences. Mojtaba Nayyeri, Chengjin Xu, Franca Hoffmann, Mirza Mohtashim Alam, Jens Lehmann 0001, Sahar Vahdati |
EMNLP (1) | 2 |
| 2021 | Time-aware Graph Neural Network for Entity Alignment between Temporal Knowledge GraphsabstractEntity alignment aims to identify equivalent entity pairs between different knowledge graphs (KGs).Recently, the availability of temporal KGs (TKGs) that contain time information created the need for reasoning over time in such TKGs.Existing embeddingbased entity alignment approaches disregard time information that commonly exists in many large-scale KGs, leaving much room for improvement.In this paper, we focus on the task of aligning entity pairs between TKGs and propose a novel Time-aware Entity Alignment approach based on Graph Neural Networks (TEA-GNN).We embed entities, relations and timestamps of different KGs into a vector space and use GNNs to learn entity representations.To incorporate both relation and time information into the GNN structure of our model, we use a time-aware attention mechanism which assigns different weights to different nodes with orthogonal transformation matrices computed from embeddings of the relevant relations and timestamps in a neighborhood.Experimental results on multiple real-world TKG datasets show that our method significantly outperforms the state-ofthe-art methods due to the inclusion of time information. Chengjin Xu, Fenglong Su, Jens Lehmann 0001 |
EMNLP (1) | 1 |
| 2021 | Multiple Run Ensemble Learning with Low-Dimensional Knowledge Graph EmbeddingsabstractKnowledge graphs (KGs) represent world facts in a structured form. Although knowledge graphs are quantitatively huge and consist of millions of triples, the coverage is still only a small fraction of world's knowledge. Among the top approaches of recent years, link prediction using knowledge graph embedding (KGE) models has gained significant attention for knowledge graph completion. Various embedding models have been proposed so far, among which, some recent KGE models obtain state-of-the-art performance on link prediction tasks by using embeddings with a high dimension (e.g. 1000) which accelerate the costs of training and evaluation considering the large scale of KGs. In this paper, we propose a simple but effective performance boosting strategy for KGE models by using multiple low dimensions in different repetition rounds of the same model. For example, instead of training a model one time with a large embedding size of 1200, we repeat the training of the model 6 times in parallel with an embedding size of 200 and then combine the 6 separate models for testing while the overall numbers of adjustable parameters are same (6*200=1200) and the total memory footprint remains the same. We show that our approach enables different models to better cope with their expressiveness issues on modeling various graph patterns such as symmetric, 1-n, n-1 and n-n. In order to justify our findings, we conduct experiments on various KGE models. Experimental results on standard benchmark datasets, namely FB15K, FB15K-237 and WN18RR, show that multiple low-dimensional models of the same kind outperform the corresponding single high-dimensional models on link prediction in a certain range and have advantages in training efficiency by using parallel training while the overall numbers of adjustable parameters are same. Chengjin Xu, Mojtaba Nayyeri, Sahar Vahdati, Jens Lehmann 0001 |
IJCNN | 1 |
| 2021 | Temporal Knowledge Graph Completion using a Linear Temporal Regularizer and Multivector EmbeddingsabstractChengjin Xu, Yung-Yu Chen, Mojtaba Nayyeri, Jens Lehmann. Proceedings of the 2021 Conference of the North American Chapter of the Association for Computational Linguistics: Human Language Technologies. 2021. Chengjin Xu, Yung-Yu Chen, Mojtaba Nayyeri, Jens Lehmann 0001 |
NAACL-HLT | 1 |
| 2021 | Loss-Aware Pattern Inference: A Correction on the Wrongly Claimed Limitations of Embedding Models
Mojtaba Nayyeri, Chengjin Xu, Yadollah Yaghoobzadeh, Sahar Vahdati, Mirza Mohtashim Alam, Hamed Shariat Yazdi, Jens Lehmann 0001 |
PAKDD (3) | 2 |
| 2020 | TeRo: A Time-aware Knowledge Graph Embedding via Temporal RotationabstractIn the last few years, there has been a surge of interest in learning representations of entities and relations in knowledge graph (KG).However, the recent availability of temporal knowledge graphs (TKGs) that contain time information for each fact created the need for reasoning over time in such TKGs.In this regard, we present a new approach of TKG embedding, TeRo, which defines the temporal evolution of entity embedding as a rotation from the initial time to the current time in the complex vector space.Specially, for facts involving time intervals, each relation is represented as a pair of dual complex embeddings to handle the beginning and the end of the relation, respectively.We show our proposed model overcomes the limitations of the existing KG embedding models and TKG embedding models and has the ability of learning and inferring various relation patterns over time.Experimental results on four different TKGs show that TeRo significantly outperforms existing state-of-the-art models for link prediction.In addition, we analyze the effect of time granularity on link prediction over TKGs, which as far as we know has not been investigated in previous literature. Chengjin Xu, Mojtaba Nayyeri, Fouad Alkhoury, Hamed Shariat Yazdi, Jens Lehmann 0001 |
COLING | 1 |
| 2020 | Knowledge Graph Embeddings in Geometric AlgebrasabstractKnowledge graph (KG) embedding aims at embedding entities and relations in a KG into a low dimensional latent representation space.Existing KG embedding approaches model entities and relations in a KG by utilizing real-valued , complex-valued, or hypercomplex-valued (Quaternion or Octonion) representations, all of which are subsumed into a geometric algebra.In this work, we introduce a novel geometric algebra-based KG embedding framework, GeomE, which utilizes multivector representations and the geometric product to model entities and relations.Our framework subsumes several state-of-the-art KG embedding approaches and is advantageous with its ability of modeling various key relation patterns, including (anti-)symmetry, inversion and composition, rich expressiveness with higher degree of freedom as well as good generalization capacity.Experimental results on multiple benchmark knowledge graphs show that the proposed approach outperforms existing state-of-the-art models for link prediction. Chengjin Xu, Mojtaba Nayyeri, Yung-Yu Chen, Jens Lehmann 0001 |
COLING | 1 |
| 2020 | Fantastic Knowledge Graph Embeddings and How to Find the Right Space for Them
Mojtaba Nayyeri, Chengjin Xu, Sahar Vahdati, Nadezhda Vassilyeva, Emanuel Sallinger, Hamed Shariat Yazdi, Jens Lehmann 0001 |
ISWC (1) | 2 |