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Collaborating Authors

 Nguyen, Dai Quoc


SQLong: Enhanced NL2SQL for Longer Contexts with LLMs

arXiv.org Artificial Intelligence

Open-weight large language models (LLMs) have significantly advanced performance in the Natural Language to SQL (NL2SQL) task. However, their effectiveness diminishes when dealing with large database schemas, as the context length increases. To address this limitation, we present SQLong, a novel and efficient data augmentation framework designed to enhance LLM performance in long-context scenarios for the NL2SQL task. SQLong generates augmented datasets by extending existing database schemas with additional synthetic CREATE TABLE commands and corresponding data rows, sampled from diverse schemas in the training data. This approach effectively simulates long-context scenarios during finetuning and evaluation. Through experiments on the Spider and BIRD datasets, we demonstrate that LLMs finetuned with SQLong-augmented data significantly outperform those trained on standard datasets. These imply SQLong's practical implementation and its impact on improving NL2SQL capabilities in real-world settings with complex database schemas.


Two-view Graph Neural Networks for Knowledge Graph Completion

arXiv.org Artificial Intelligence

To this end, we propose a new KG embedding model, named A knowledge graph (KG) is a network of entity nodes and WGE, to leverage GNNs to capture entity-focused graph structure relationship edges, which can be represented as a collection and relation-focused graph structure for KG completion. of triples in the form of (h, r, t), wherein each triple (h, r, In particular, WGE transforms a given KG into two views. The t) represents a relation r between a head entity h and a tail first view--a single undirected entity-focused graph--only entity t. Here, entities are real-world things or objects such includes entities as nodes to provide the entity neighborhood as music tracks, movies persons, organizations, places and the information. The second view--a single undirected relationfocused like, while each relation type determines a certain relationship graph--considers both entities and relations as nodes, between entities. KGs are used in a number of commercial applications, constructed from constraints (subjective relation, predicate e.g. in such search engines as Google, Microsoft's entity, objective relation), to attain the potential dependence Bing and Facebook's Graph search. They also are useful between two neighborhood relations. Then WGE introduces a resources for many natural language processing tasks such as new encoder module of adopting two vanilla GNNs directly co-reference resolution ([1], [2]), semantic parsing ([3], [4]) on these two graph views to better update entity and relation and question answering ([5], [6]). However, an issue is that embeddings, followed by the decoder module using a weighted KGs are often incomplete, i.e., missing a lot of valid triples score function. In summary, our contributions are as follows: [7].


Quaternion Graph Neural Networks

arXiv.org Machine Learning

Recently, graph neural networks (GNNs) become a principal research direction to learn low-dimensional continuous embeddings of nodes and graphs to predict node and graph labels, respectively. However, Euclidean embeddings have high distortion when using GNNs to model complex graphs such as social networks. Furthermore, existing GNNs are not very efficient with the high number of model parameters when increasing the number of hidden layers. Therefore, we move beyond the Euclidean space to a hyper-complex vector space to improve graph representation quality and reduce the number of model parameters. To this end, we propose quaternion graph neural networks (QGNN) to generalize GCNs within the Quaternion space to learn quaternion embeddings for nodes and graphs. The Quaternion space, a hyper-complex vector space, provides highly meaningful computations through Hamilton product compared to the Euclidean and complex vector spaces. As a result, our QGNN can reduce the model size up to four times and enhance learning better graph representations. Experimental results show that the proposed QGNN produces state-of-the-art accuracies on a range of well-known benchmark datasets for three downstream tasks, including graph classification, semi-supervised node classification, and text (node) classification.


QuatRE: Relation-Aware Quaternions for Knowledge Graph Embeddings

arXiv.org Artificial Intelligence

We propose a simple and effective embedding model, named QuatRE, to learn quaternion embeddings for entities and relations in knowledge graphs. QuatRE aims to enhance correlations between head and tail entities given a relation within the Quaternion space with Hamilton product. QuatRE achieves this by associating each relation with two quaternion vectors which are used to rotate the quaternion embeddings of the head and tail entities, respectively. To obtain the triple score, QuatRE rotates the rotated embedding of the head entity using the normalized quaternion embedding of the relation, followed by a quaternion-inner product with the rotated embedding of the tail entity. Experimental results show that our QuatRE outperforms up-to-date embedding models on well-known benchmark datasets for knowledge graph completion.


A Self-Attention Network based Node Embedding Model

arXiv.org Machine Learning

Despite several signs of progress have been made recently, limited research has been conducted for an inductive setting where embeddings are required for newly unseen nodes -- a setting encountered commonly in practical applications of deep learning for graph networks. This significantly affects the performances of downstream tasks such as node classification, link prediction or community extraction. To this end, we propose SANNE -- a novel unsupervised embedding model -- whose central idea is to employ a transformer self-attention network to iteratively aggregate vector representations of nodes in random walks. Our SANNE aims to produce plausible embeddings not only for present nodes, but also for newly unseen nodes. Experimental results show that the proposed SANNE obtains state-of-the-art results for the node classification task on well-known benchmark datasets.


Unsupervised Universal Self-Attention Network for Graph Classification

arXiv.org Machine Learning

Existing graph embedding models often have weaknesses in exploiting graph structure similarities, potential dependencies among nodes and global network properties. To this end, we present U2GAN, a novel unsupervised model leveraging on the strength of the recently introduced universal self-attention network (Dehghani et al., 2019), to learn low-dimensional embeddings of graphs which can be used for graph classification. In particular, given an input graph, U2GAN first applies a self-attention computation, which is then followed by a recurrent transition to iteratively memorize its attention on vector representations of each node and its neighbors across each iteration. Thus, U2GAN can address the weaknesses in the existing models in order to produce plausible node embeddings whose sum is the final embedding of the whole graph. Experimental results show that our unsupervised U2GAN produces new state-of-the-art performances on a range of well-known benchmark datasets for the graph classification task. It even outperforms supervised methods in most of benchmark cases.