HG
PhD Researcher · Artificial Intelligence

Haji Gul

Universiti Brunei Darussalam

I research knowledge graphs, natural language processing, and complex network analysis — with a focus on knowledge graph completion, link prediction, and graph clustering.

Research Interest

My research interests encompass knowledge graphs (KG), complex networks (protein–protein interaction networks, Yeast, C. elegans neurons, E. coli) and social network analysis (Karate, Dolphins). This includes knowledge graph completion (KGC), link prediction (LP), graph clustering, natural language processing (NLP), and recommendation systems, with applications in pattern recognition and complex network analysis. My PhD focuses on knowledge graphs (completion, evaluation, complexity, link prediction), NLP, Transformers, and LLMs.

NLPKnowledge Graph CompletionLink Prediction KG EvaluationGraph ClusteringComplex Networks Community DetectionMachine LearningDeep Learning Pre-trained Language ModelsTransformersLLMsRecommendations

Recognition

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DAAD AInet Fellowship · 2025

Awarded the DAAD AInet Fellowship in Natural Language Processing (May 2025). Currently collaborating with Leuphana University, Germany.

Selected Papers

A selection of my recent work. Click any paper to read the abstract and view figures.

1
MuCo-KGC: Multi-Context-Aware Knowledge Graph Completion
PAKDD 2025
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Abstract

Knowledge Graph Completion (KGC) seeks to predict missing entities (e.g., heads or tails) or relationships in knowledge graphs (KGs), which often contain incomplete data. Traditional embedding-based methods, such as TransE and ComplEx, have improved tail entity prediction but struggle to generalize to unseen entities during testing. Textual-based models mitigate this issue by leveraging additional semantic context; however, their reliance on negative triplet sampling introduces high computational overhead, semantic inconsistencies, and data imbalance. Recent approaches, like KG-BERT, show promise but depend heavily on entity descriptions, which are often unavailable in KGs. Critically, existing methods overlook valuable structural information in the KG related to the entities and relationships. To address these challenges, we propose Multi-Context-Aware Knowledge Graph Completion (MuCo-KGC), a novel model that utilizes contextual information from linked entities and relations within the graph to predict tail entities. MuCo-KGC eliminates the need for entity descriptions and negative triplet sampling, significantly reducing computational complexity while enhancing performance. Our experiments on standard datasets, including FB15k-237, WN18RR, CoDEx-S, and CoDEx-M, demonstrate that MuCo-KGC outperforms state-of-the-art methods on three datasets. Notably, MuCo-KGC improves MRR on WN18RR, CoDEx-S, and CoDEx-M datasets by 1.63%, 3.77%, and 20.15% respectively, demonstrating its effectiveness for KGC tasks.

MuCo-KGC model pipeline
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Figure 1 — Overview of the MuCo-KGC model pipeline for predicting the tail entity, given a head entity h and relationship r. The left box shows the head context Hc (union of relations R(h) and neighbouring entities E(h)); the right box shows the relationship context Rc. These contextual features, alongside h and r, are fed into a BERT model with a linear classifier and softmax to generate tail-entity probabilities.
Cite (BibTeX)
@inproceedings{gul-2025-mucokgc,
    title = "MuCo-KGC: Multi-Context-Aware Knowledge Graph Completion",
    author = "Gul, Haji and Naim, Abdul Ghani and Bhat, Ajaz Ahmad",
    booktitle = "Advances in Knowledge Discovery and Data Mining (PAKDD)",
    year = "2025",
    publisher = "Springer",
    doi = "10.1007/978-981-96-8298-0_1",
    url = "https://dl.acm.org/doi/10.1007/978-981-96-8298-0_1"
}
2
MuCoS: Efficient Drug-Target Prediction through Multi-Context-Aware Sampling
BioNLP Workshop @ ACL SIGBIOMED 2025
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Abstract

Accurate prediction of drug-target interactions is critical for accelerating drug discovery. In this work, we frame drug-target prediction as a link prediction task on heterogeneous biomedical knowledge graphs (KGs) that integrate drugs, proteins, diseases, pathways, and other relevant entities. Conventional KG embedding methods such as TransE and ComplEx are hindered by their reliance on computationally intensive negative sampling and their limited generalization to unseen drug-target pairs. To address these challenges, we propose Multi-Context-Aware Sampling (MuCoS), a novel framework that prioritizes high-density neighbours to capture salient structural patterns and integrates these with contextual embeddings derived from BERT. By unifying structural and textual modalities and selectively sampling highly informative patterns, MuCoS eliminates the need for negative sampling, significantly reduces computational overhead, and improves generalization to unseen drug-target pairs and targets. Extensive experiments on the KEGG50k and PharmKG-8k datasets demonstrate that MuCoS outperforms competitive baselines, achieving up to 13% improvement in MRR for general relation prediction on KEGG50k, up to 22% improvement in MRR on PharmKG-8k, and up to 6% improvement in dedicated drug-target relation prediction on KEGG50k.

MuCoS overall pipeline
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Figure 1 — Overview of the MuCoS model pipeline for predicting general and drug-target relations and tail entities. The left boxes show the input sequence to BERT: (h) head, (Hc) head context, (t) tail, (Tc) tail context, (r) relation, and (Rc) relation context. This integrated context passes through BERT with a linear classifier and softmax to produce probabilities for relations and tails.
MuCoS head context construction
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Figure 2 — Head context (Hc) construction with sampling. The one-hop head context consists of the relation set R(h) and neighbouring tail entities E(h). Only the top-n tail entities are selected and concatenated based on their density ρ(e) to form the optimized head context.
MuCoS relation context construction
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Figure 3 — Relation context (Rc) construction with sampling. The top-k entities are selected by density ρ, retaining the most informative head-tail pairs, which are then aggregated by concatenation to form the optimized relation context.
Cite (BibTeX)
@inproceedings{gul-etal-2025-mucos,
    title = "{M}u{C}o{S}: Efficient Drug{--}Target Discovery via Multi-Context-Aware Sampling in Knowledge Graphs",
    author = "Gul, Haji and Naim, Abdul Ghani and Bhat, Ajaz Ahmad",
    editor = "Demner-Fushman, Dina and Ananiadou, Sophia and Miwa, Makoto and Tsujii, Junichi",
    booktitle = "Proceedings of the 24th Workshop on Biomedical Language Processing",
    month = aug,
    year = "2025",
    address = "Viena, Austria",
    publisher = "Association for Computational Linguistics",
    url = "https://aclanthology.org/2025.bionlp-1.27/",
    doi = "10.18653/v1/2025.bionlp-1.27",
    pages = "319--327",
    ISBN = "979-8-89176-275-6"
}
3
When Metrics Disagree: A Meta-Analysis of Knowledge-Graph-Completion Model Benchmarking
arXiv 2026 · Under Review
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Abstract

[ Paste the abstract for When Metrics Disagree here. ]

When Metrics Disagree figure 1
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Figure 1 — add your caption here.
4
KG-EDAS: A Meta-Metric Framework for Evaluating Knowledge Graph Completion Models
IEEE BigData 2025
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Abstract

[ Paste the abstract for KG-EDAS here. ]

KG-EDAS figure 1
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Figure 1 — add your caption here.
5
Evaluating Knowledge Graph Complexity via Semantic, Spectral, and Structural Metrics for Link Prediction
IEEE BigData 2025
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Abstract

[ Paste the abstract for this paper here. ]

KG complexity figure 1
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Figure 1 — add your caption here.
6
Evaluating Cumulative Spectral Gradient as a Complexity Measure
MusIML Workshop @ ICML 2025
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Abstract

[ Paste the abstract for this paper here. ]

Cumulative spectral gradient figure 1
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Figure 1 — add your caption here.
7
Domain-Aware Evaluation of Knowledge Graph Completion Models Using KG-EDAS
GCLR Workshop @ AAAI
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Abstract

[ Paste the abstract for this paper here. ]

Domain-aware KG-EDAS figure 1
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Figure 1 — add your caption here.
8
A Contextualized BERT Model for Knowledge Graph Completion
MusIML Workshop @ NeurIPS 2024
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Abstract

[ Paste the abstract for this paper here. ]

Contextualized BERT KGC figure 1
Add image: Figures/bert-kgc-1.png
Figure 1 — add your caption here.

Contact

Phone / WhatsApp
+92-307-8297663
References
Dr. Ajaz Ahmad Bhat — Assistant Professor, School of Digital Science, UBD · ajaz.bhat@ubd.edu.bn
Dr. Abdul Ghani Naim — Assistant Professor, School of Digital Science, UBD · ghani.naim@ubd.edu.bn
Dr. Adnan Amin — Assistant Professor, Institute of Management Sciences, Peshawar · adnan.amin@imsciences.edu.pk