Link prediction in knowledge graph is the task of utilizing the existing relations to infer new relations so as to build a more complete knowledge graph. The inferred new relations plus original knowledge graph is the symmetry of completion knowledge graph. Previous research on link predication only focuses on path or semantic-based features, which can hardly have a full insight of features between entities and may result in a certain ratio of false inference results. To improve the accuracy of link predication, we propose a novel approach named Entity Link Prediction for Knowledge Graph (ELPKG), which can achieve a high accuracy on large-scale knowledge graphs while keeping desirable efficiency. ELPKG first combines path and semantic-based features together to represent the relationships between entities. Then it adopts a probabilistic soft logic-based reasoning method that effectively solves the problem of non-deterministic knowledge reasoning. Finally, the relation between entities is completed based on the entity link prediction algorithm. Extensive experiments on real dataset show that ELPKG outperforms baseline methods on hits@1, hits@10, and MRR.

Since the facts in the knowledge graph (KG) cannot be updated automatically over time, some facts have temporal conflicts. To discover and eliminate the temporal conflicts in the KG, this paper proposes a novel temporal conflict resolution method based on temporal KG embedding (named TeCre). Firstly, the predicate relation and timestamp information of time series are incorporated into the entity–relation embedding representation by leveraging the temporal KG embedding (KGE) method. Then, taking into account the chronological sequence of the evolution of the entity–relation representation over time, TeCre constrains the temporal relation in the KG according to the principles of time disjoint, time precedence, and time mutually exclusive constraints. Besides that, TeCre further considers the sequence vectorization of predicate relation to discover the temporal conflict facts in the KG. Finally, to eliminate the temporal conflict facts, TeCre deletes the tail entities of the temporal conflict facts, and employs the link prediction method to complete the missing tail entities according to the output of the score function based on the entity–relation embedding. Experimental results on four public datasets show that TeCre is significantly better than the state-of-the-art temporal KG conflict resolution model. The mean reciprocal ranking (MRR) and Hits@10 of TeCre are at least 5.46% and 3.2% higher than the baseline methods, respectively.

In the digital age, software security is essential for the stability of information systems and data protection, yet increasing complexity in software systems has made vulnerabilities a significant cybersecurity threat, leading to data breaches, system crashes, and service disruptions. Traditional vulnerability assessments usually analyze vulnerabilities in isolation, ignoring their time relations and the risk of attackers exploiting multiple vulnerabilities simultaneously, known as co-exploitation. This paper proposes an innovative time-aware cybersecurity knowledge graph (TCG) reasoning method called TCGFormer, which is designed to address these challenges. TCGFormer comprises four modules: (1) an entity encoding module that adjusts attention based on positional information and interaction frequency, (2) a novel attention mechanism for encoding relational topology graphs, (3) a joint sequence encoding module for extracting temporal representations and node relations from historical interactions, and (4) a parameter learning module for predicting entities and relations. Extensive experiments on three public temporal datasets demonstrate that TCGFormer significantly outperforms existing baseline methods, and validation on a cybersecurity knowledge graph dataset—including NVD, CVE details, CWE database, and EDB—further confirms its efficacy in identifying co-exploitation behaviors.