Pengcheng Jiang

dblp:60/8352 · DBLP profile ↗
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20ranked-venue papers
13as first author
19since 2021 · last 2026
—ORCID · conflict

Domains — the database's venue-derived domains; a paper can count in several

Artificial intelligence and machine learning · 16 · 12 first-author · 16 since 2021Databases, data management, data science and information retrieval · 3 · 2 first-author · 3 since 2021Applied, interdisciplinary, general and emerging computing · 2 · 1 first-author · 2 since 2021Computer networks · 1Graphics, computer vision, multimedia, augmented reality and games · 1 · 1 first-author · 1 since 2021Human-computer interaction and ubiquitous computing · 1 · 1 since 2021
YearPublicationVenuePosition
2026 PairSem: LLM-Guided Pairwise Semantic Matching for Scientific Document Retrieval
Wonbin Kweon, Runchu Tian, Seongku Kang, Pengcheng Jiang, Zhiyong Lu, Jiawei Han 0001, Hwanjo Yu
WWW4
2026 Evolutionary Channel Pruning for Style-Based Generative Adversarial Networks
abstract
Generative Adversarial Networks (GANs) have demonstrated remarkable success in high-quality image synthesis, with StyleGAN and its successor, StyleGAN2, achieving state-of-the-art performance in terms of realism and control over generated features. However, the large number of parameters and high floating-point operations per second (FLOPs) hinder real-time applications and scalability, posing challenges for deploying these models in resource-constrained environments such as edge devices and mobile platforms. To address this issue, we propose Evolutionary Channel Pruning for StyleGANs (ECP-StyleGANs), a novel algorithm that leverages evolutionary algorithms to compress StyleGAN and StyleGAN2 while maintaining competitive image quality. Our approach encodes pruning configurations as binary masks on the model's convolutional channels and iteratively refines them through selection, crossover, and mutation. By integrating carefully designed fitness functions that balance model complexity and generation quality, ECP-StyleGANs identifies optimally pruned architectures that reduce computational demands without compromising visual fidelity, achieving approximately a 4 × reduction in FLOPs and parameters, while maintaining visual fidelity with only a slight increase in FID (Fréchet Inception Distance) compared to the original un-pruned model. This study should be interpreted as a preliminary step towards the formulation and management of the generative AI pruning problem as a multi-objective optimisation task, aimed at enhancing the trade-off between model efficiency and image quality, thereby making large deep models more accessible for real-world applications such as edge devices and resource-constrained environments.
Yixia Zhang, Ferrante Neri, Xilu Wang 0001, Pengcheng Jiang, Yu Xue 0003
Int. J. Neural Syst.4
2026 A Pairwise Comparison Relation-Assisted Multiobjective Evolutionary Neural Architecture Search Method With Multipopulation Mechanism
abstract
Neural architecture search (NAS) has emerged as a powerful paradigm that enables researchers to automatically explore vast search spaces and discover efficient neural networks. However, NAS suffers from a critical bottleneck, i.e., the evaluation of numerous architectures during the search process demands substantial computing resources and time. In order to improve the efficiency of NAS, a series of methods have been proposed to reduce the evaluation time of neural architectures. However, they are not efficient enough and still only focus on the accuracy of architectures. Beyond classification accuracy, real-world applications increasingly demand more efficient and compact network architectures that balance multiple performance criteria. To address these challenges, we propose the SMEMNAS, a pairwise comparison relation-assisted multiobjective evolutionary algorithm (EA) based on a multipopulation (MP) mechanism. In the SMEMNAS, a surrogate model is constructed based on pairwise comparison relations to predict the accuracy ranking of architectures, rather than the absolute accuracy. Moreover, two populations cooperate with each other in the search process, i.e., a main population that guides the evolutionary process and a vice population that enhances search diversity. Our method aims to discover high-performance models that simultaneously optimize multiple objectives. We conduct comprehensive experiments on CIFAR-10, CIFAR-100, and ImageNet datasets to validate the effectiveness of our approach. With only a single GPU searching for 0.17 days, competitive architectures can be found by SMEMNAS, which achieves 78.91% accuracy with the MAdds of 570 M on the ImageNet. This work makes a significant advancement in the field of NAS.
Yu Xue 0003, Pengcheng Jiang, Chenchen Zhu, MengChu Zhou, Mohamed Wahib, Moncef Gabbouj
IEEE Trans. Syst. Man Cybern. Syst.2
2025 Bi-level Contrastive Learning for Knowledge-Enhanced Molecule Representations
abstract
Molecular representation learning is vital for various downstream applications, including the analysis and prediction of molecular properties and side effects. While Graph Neural Networks (GNNs) have been a popular framework for modeling molecular data, they often struggle to capture the full complexity of molecular representations. In this paper, we introduce a novel method called Gode, which accounts for the dual-level structure inherent in molecules. Molecules possess an intrinsic graph structure and simultaneously function as nodes within a broader molecular knowledge graph. Gode integrates individual molecular graph representations with multi-domain biochemical data from knowledge graphs. By pre-training two GNNs on different graph structures and employing contrastive learning, Gode effectively fuses molecular structures with their corresponding knowledge graph substructures. This fusion yields a more robust and informative representation, enhancing molecular property predictions by leveraging both chemical and biological information. When fine-tuned across 11 chemical property tasks, our model significantly outperforms existing benchmarks, achieving an average ROC-AUC improvement of 12.7% for classification tasks and an average RMSE/MAE improvement of 34.4% for regression tasks. Notably, Gode surpasses the current leading model in property prediction, with advancements of 2.2% in classification and 7.2% in regression tasks.
Pengcheng Jiang, Cao Xiao, Tianfan Fu, Parminder Bhatia, Taha A. Kass-Hout, Jimeng Sun 0001, Jiawei Han 0001
AAAI1
2025 Homogeneous Architecture Augmentation and Confidence Prediction for Evolutionary Neural Architecture Search
abstract
Evolutionary neural architecture search (ENAS) automates the design of high-performing neural networks but is often hindered by the high computational cost of evaluating individual architectures. Surrogate models mitigate this issue by predicting performance, yet their accuracy depends on the quality of training data and their ability to utilise insights from real evaluations. This paper presents homogeneous encoding-based ENAS (HENAS), a novel method addressing these challenges through two key innovations: homogeneous architecture augmentation and confidence-based prediction. Through homogeneous architecture augmentation, HENAS exploits redundant encodings in the MobileNetV3 search space to generate multiple representations of the same architecture, enhancing the surrogate model’s training data without additional cost. Confidence-based prediction introduces a mechanism to identify architectures with uncertain performance estimates, prioritising them for evaluation. Integrated into an evolutionary framework, these techniques improve search efficiency and exploration. Experiments on CIFAR-10, CIFAR-100, and ImageNet show that HENAS achieves state-of-the-art performance with reduced computational expense. Ablation studies confirm the contributions of its core components, highlighting the value of redundancy exploitation and uncertainty management in surrogate-assisted ENAS.
Pengcheng Jiang, Yu Xue 0003, Ferrante Neri
CEC1
2025 s3: You Don't Need That Much Data to Train a Search Agent via RL
abstract
Retrieval-augmented generation (RAG) systems empower large language models (LLMs) to access external knowledge during inference.Recent advances have enabled LLMs to act as search agents via reinforcement learning (RL), improving information acquisition through multi-turn interactions with retrieval engines.However, existing approaches either optimize retrieval using search-only metrics (e.g., NDCG) that ignore downstream utility or fine-tune the entire LLM to jointly reason and retrieve-entangling retrieval with generation and limiting the real search utility and compatibility with frozen or proprietary models.In this work, we propose s3, a lightweight, modelagnostic framework that decouples the searcher from the generator and trains the searcher using a Gain Beyond RAG reward: the improvement in generation accuracy over naïve RAG.s3 requires only 2.4k training samples to outperform baselines trained on over 70× more data, consistently delivering stronger downstream performance across six general QA and five medical QA benchmarks. 1
Pengcheng Jiang, Xueqiang Xu, Jiacheng Lin, Jinfeng Xiao, Zifeng Wang 0008, Jimeng Sun 0001, Jiawei Han 0001
EMNLP1
2025 Topic Coverage-based Demonstration Retrieval for In-Context Learning
abstract
The effectiveness of in-context learning relies heavily on selecting demonstrations that provide all the necessary information for a given test input.To achieve this, it is crucial to identify and cover fine-grained knowledge requirements.However, prior methods often retrieve demonstrations based solely on embedding similarity or generation probability, resulting in irrelevant or redundant examples.In this paper, we propose TopicK, a topic coverage-based retrieval framework that selects demonstrations to comprehensively cover topiclevel knowledge relevant to both the test input and the model.Specifically, TopicK estimates the topics required by the input and assesses the model's knowledge on those topics.TopicK then iteratively selects demonstrations that introduce previously uncovered required topics, in which the model exhibits low topical knowledge.We validate the effectiveness of TopicK through extensive experiments across various datasets and both
Wonbin Kweon, Seongku Kang, Runchu Tian, Pengcheng Jiang, Jiawei Han 0001, Hwanjo Yu
EMNLP4
2025 Reasoning-Enhanced Healthcare Predictions with Knowledge Graph Community Retrieval
abstract
Large language models (LLMs) have demonstrated significant potential in clinical decision support. Yet LLMs still suffer from hallucinations and lack fine-grained contextual medical knowledge, limiting their high-stake healthcare applications such as clinical diagnosis. Traditional retrieval-augmented generation (RAG) methods attempt to address these limitations but frequently retrieve sparse or irrelevant information, undermining prediction accuracy. We introduce KARE, a novel framework that integrates knowledge graph (KG) community-level retrieval with LLM reasoning to enhance healthcare predictions. KARE constructs a comprehensive multi-source KG by integrating biomedical databases, clinical literature, and LLM-generated insights, and organizes it using hierarchical graph community detection and summarization for precise and contextually relevant information retrieval. Our key innovations include: (1) a dense medical knowledge structuring approach enabling accurate retrieval of relevant information; (2) a dynamic knowledge retrieval mechanism that enriches patient contexts with focused, multi-faceted medical insights; and (3) a reasoning-enhanced prediction framework that leverages these enriched contexts to produce both accurate and interpretable clinical predictions. Extensive experiments demonstrate that KARE outperforms leading models by up to 10.8-15.0\% on MIMIC-III and 12.6-12.7\% on MIMIC-IV for mortality and readmission predictions. In addition to its impressive prediction accuracy, our framework leverages the reasoning capabilities of LLMs, enhancing the trustworthiness of clinical predictions.
Pengcheng Jiang, Cao Xiao, Minhao Jiang, Parminder Bhatia, Taha A. Kass-Hout, Jimeng Sun 0001, Jiawei Han 0001
ICLR1
2025 Retrieval And Structuring Augmented Generation with Large Language Models
abstract
Large Language Models (LLMs) have revolutionized natural language processing with their remarkable capabilities in text generation and reasoning. However, these models face critical challenges when deployed in real-world applications, including hallucination generation, outdated knowledge, and limited domain expertise. Retrieval And Structuring (RAS) Augmented Generation addresses these limitations by integrating dynamic information retrieval with structured knowledge representations. This survey (1) examines retrieval mechanisms including sparse, dense, and hybrid approaches for accessing external knowledge; (2) explore text structuring techniques such as taxonomy construction, hierarchical classification, and information extraction that transform unstructured text into organized representations; and (3) investigate how these structured representations integrate with LLMs through prompt-based methods, reasoning frameworks, and knowledge embedding techniques. It also identifies technical challenges in retrieval efficiency, structure quality, and knowledge integration, while highlighting research opportunities in multimodal retrieval, cross-lingual structures, and interactive systems. This comprehensive overview provides researchers and practitioners with insights into RAS methods, applications, and future directions.
Pengcheng Jiang, Siru Ouyang, Yizhu Jiao, Ming Zhong 0005, Runchu Tian, Jiawei Han 0001
KDD (2)1
2024 Taxonomy-guided Semantic Indexing for Academic Paper Search
abstract
Academic paper search is an essential task for efficient literature discovery and scientific advancement.While dense retrieval has advanced various ad-hoc searches, it often struggles to match the underlying academic concepts between queries and documents, which is critical for paper search.To enable effective academic concept matching for paper search, we propose Taxonomy-guided semantic Indexing (TaxoIndex) framework.TaxoIndex extracts key concepts from papers and organizes them as a semantic index guided by an academic taxonomy, and then leverages this index as foundational knowledge to identify academic concepts and link queries and documents.As a plug-and-play framework, TaxoIndex can be flexibly employed to enhance existing dense retrievers.Extensive experiments show that Tax-oIndex brings significant improvements, even with highly limited training data, and greatly enhances interpretability.
Seongku Kang, Yunyi Zhang 0001, Pengcheng Jiang, Dongha Lee 0003, Jiawei Han 0001, Hwanjo Yu
EMNLP3
2024 Surrogate-Assisted Evolutionary Neural Architecture Search with Isomorphic Training and Prediction
Pengcheng Jiang, Yu Xue 0003, Ferrante Neri, Mohamed Wahib
ICIC (2)1
2024 GraphCare: Enhancing Healthcare Predictions with Personalized Knowledge Graphs
abstract
Clinical predictive models often rely on patients’ electronic health records (EHR), but integrating medical knowledge to enhance predictions and decision-making is challenging. This is because personalized predictions require personalized knowledge graphs (KGs), which are difficult to generate from patient EHR data. To address this, we propose GraphCare, an open-world framework that uses external KGs to improve EHR-based predictions. Our method extracts knowledge from large language models (LLMs) and external biomedical KGs to build patient-specific KGs, which are then used to train our proposed Bi-attention AugmenTed (BAT) graph neural network (GNN) for healthcare predictions. On two public datasets, MIMIC-III and MIMIC-IV, GraphCare surpasses baselines in four vital healthcare prediction tasks: mortality, readmission, length of stay (LOS), and drug recommendation. On MIMIC-III, it boosts AUROC by 17.6% and 6.6% for mortality and readmission, and F1-score by 7.9% and 10.8% for LOS and drug recommendation, respectively. Notably, GraphCare demonstrates a substantial edge in scenarios with limited data availability. Our findings highlight the potential of using external KGs in healthcare prediction tasks and demonstrate the promise of GraphCare in generating personalized KGs for promoting personalized medicine.
Pengcheng Jiang, Cao Xiao, Adam R. Cross, Jimeng Sun 0001
ICLR1
2024 Robust Representation Learning for Image Clustering
Pengcheng Jiang, Ye Zhu 0002, Yang Cao 0019, Gang Li 0009, Gang Liu 0021, Bo Yang 0002
KSEM (4)1
2024 GenRES: Rethinking Evaluation for Generative Relation Extraction in the Era of Large Language Models
abstract
Pengcheng Jiang, Jiacheng Lin, Zifeng Wang, Jimeng Sun, Jiawei Han. Proceedings of the 2024 Conference of the North American Chapter of the Association for Computational Linguistics: Human Language Technologies (Volume 1: Long Papers). 2024.
Pengcheng Jiang, Jiacheng Lin, Zifeng Wang 0008, Jimeng Sun 0001, Jiawei Han 0001
NAACL-HLT1
2024 TriSum: Learning Summarization Ability from Large Language Models with Structured Rationale
abstract
Pengcheng Jiang, Cao Xiao, Zifeng Wang, Parminder Bhatia, Jimeng Sun, Jiawei Han. Proceedings of the 2024 Conference of the North American Chapter of the Association for Computational Linguistics: Human Language Technologies (Volume 1: Long Papers). 2024.
Pengcheng Jiang, Cao Xiao, Zifeng Wang 0008, Parminder Bhatia, Jimeng Sun 0001, Jiawei Han 0001
NAACL-HLT1
2024 KG-FIT: Knowledge Graph Fine-Tuning Upon Open-World Knowledge
abstract
Knowledge Graph Embedding (KGE) techniques are crucial in learning compact representations of entities and relations within a knowledge graph, facilitating efficient reasoning and knowledge discovery. While existing methods typically focus either on training KGE models solely based on graph structure or fine-tuning pre-trained language models with classification data in KG, KG-FIT leverages LLM-guided refinement to construct a semantically coherent hierarchical structure of entity clusters. By incorporating this hierarchical knowledge along with textual information during the fine-tuning process, KG-FIT effectively captures both global semantics from the LLM and local semantics from the KG. Extensive experiments on the benchmark datasets FB15K-237, YAGO3-10, and PrimeKG demonstrate the superiority of KG-FIT over state-of-the-art pre-trained language model-based methods, achieving improvements of 14.4\%, 13.5\%, and 11.9\% in the Hits@10 metric for the link prediction task, respectively. Furthermore, KG-FIT yields substantial performance gains of 12.6\%, 6.7\%, and 17.7\% compared to the structure-based base models upon which it is built. These results highlight the effectiveness of KG-FIT in incorporating open-world knowledge from LLMs to significantly enhance the expressiveness and informativeness of KG embeddings.
Pengcheng Jiang, Lang Cao, Cao Xiao, Parminder Bhatia, Jimeng Sun 0001, Jiawei Han 0001
NeurIPS1
2024 A Generalized Attention Mechanism to Enhance the Accuracy Performance of Neural Networks
abstract
In many modern machine learning (ML) models, attention mechanisms (AMs) play a crucial role in processing data and identifying significant parts of the inputs, whether these are text or images. This selective focus enables subsequent stages of the model to achieve improved classification performance. Traditionally, AMs are applied as a preprocessing substructure before a neural network, such as in encoder/decoder architectures. In this paper, we extend the application of AMs to intermediate stages of data propagation within ML models. Specifically, we propose a generalized attention mechanism (GAM), which can be integrated before each layer of a neural network for classification tasks. The proposed GAM allows for at each layer/step of the ML architecture identification of the most relevant sections of the intermediate results. Our experimental results demonstrate that incorporating the proposed GAM into various ML models consistently enhances the accuracy of these models. This improvement is achieved with only a marginal increase in the number of parameters, which does not significantly affect the training time.
Pengcheng Jiang, Ferrante Neri, Yu Xue 0003, Ujjwal Maulik
Int. J. Neural Syst.1
2023 Continuously evolving dropout with multi-objective evolutionary optimisation
abstract
Dropout is an effective method of mitigating over-fitting while training deep neural networks (DNNs). This method consists of switching off (dropping) some of the neurons of the DNN and training it by keeping the remaining neurons active. This approach makes the DNN general and resilient to changes in its inputs. However, the probability of a neuron belonging to a layer to be dropped, the ’dropout rate’, is a hard-to-tune parameter that affects the performance of the trained model. Moreover, there is no reason, besides being more practical during parameter tuning, why the dropout rate should be the same for all neurons across a layer. This paper proposes a novel method to guide the dropout rate based on an evolutionary algorithm . In contrast to previous studies, we associate a dropout with each individual neuron of the network, thus allowing more flexibility in the training phase. The vector encoding the dropouts for the entire network is interpreted as the candidate solution of a bi-objective optimisation problem, where the first objective is the error reduction due to a set of dropout rates for a given data batch, while the second objective is the distance of the used dropout rates from a pre-arranged constant. The second objective is used to control the dropout rates and prevent them from becoming too small, hence ineffective; or too large, thereby dropping a too-large portion of the network. Experimental results show that the proposed method, namely GADropout, produces DNNs that consistently outperform DNNs designed by other dropout methods, some of them being modern advanced dropout methods representing the state-of-the-art. GADroput has been tested on multiple datasets and network architectures.
Pengcheng Jiang, Yu Xue 0003, Ferrante Neri
Eng. Appl. Artif. Intell.1
2021 A Multi-Objective Evolutionary Approach Based on Graph-in-Graph for Neural Architecture Search of Convolutional Neural Networks
abstract
With the development of deep learning, the design of an appropriate network structure becomes fundamental. In recent years, the successful practice of Neural Architecture Search (NAS) has indicated that an automated design of the network structure can efficiently replace the design performed by human experts. Most NAS algorithms make the assumption that the overall structure of the network is linear and focus solely on accuracy to assess the performance of candidate networks. This paper introduces a novel NAS algorithm based on a multi-objective modeling of the network design problem to design accurate Convolutional Neural Networks (CNNs) with a small structure. The proposed algorithm makes use of a graph-based representation of the solutions which enables a high flexibility in the automatic design. Furthermore, the proposed algorithm includes novel ad-hoc crossover and mutation operators. We also propose a mechanism to accelerate the evaluation of the candidate solutions. Experimental results demonstrate that the proposed NAS approach can design accurate neural networks with limited size.
Yu Xue 0003, Pengcheng Jiang, Ferrante Neri, Jiayu Liang
Int. J. Neural Syst.2
2018 Data Driven Congestion Trends Prediction of Urban Transportation
abstract
Smart traffic prediction system provides significant benefits in solving the city traffic congestion. However, existing smart transportation system needs a lot of real-time traffic data and accurate location information to display the traffic condition. We hope that we can use the data which is easy to be obtained, and then predict a reliable congestion time. To address this problem, this paper studied a smart traffic forecasting system based on SWARIMA model. The system includes three steps: 1) use the sliding windows to calculate and process real-time data stream; 2) establish the SWARIMA model and make regression analysis; and 3) from a statistical point of view, calculate the elastic interval and predict the congestion trend. Our system is capable of accepting the real-time traffic data stream for the congestion prediction, in addition, we reduce the actual running parameters to three attributes: 1) speed; 2) time; and 3) location information. When faced with the challenges of real-time traffic congestion, the system can timely and effectively calculate the congestion trends and provide three reliable elastic intervals: 1) warning; 2) congestion; and 3) mitigation, which has significance to improve traffic condition and alleviate urban road congestion.
Rui Jia, Pengcheng Jiang, Lei Liu 0003, Li-Zhen Cui 0001, Yuliang Shi
IEEE Internet Things J.2