Scaled and Inter-token Relation Enhanced Transformer for Sample-restricted Residential NILM

Recent advancements in transformer models have yielded impressive results in Non-Intrusive Load Monitoring (NILM). However, effectively training a transformer on small-scale datasets remains a challenge. This paper addresses this issue by enhancing the attention mechanism of the original transformer to improve performance. We propose two novel mechanisms: the inter-token relation enhancement mechanism and the dynamic temperature tuning mechanism. The first mechanism reduces the prioritization of intra-token relationships in the token similarity matrix during training, thereby increasing inter-token focus. The second mechanism introduces a learnable temperature tuning for the token similarity matrix, mitigating the over-smoothing problem associated with fixed temperature values. Both mechanisms are supported by rigorous mathematical foundations. We evaluate our approach using the REDD residential NILM dataset, a relatively small-scale dataset and demonstrate that our methodology significantly enhances the performance of the original transformer model across multiple appliance types.

Towards a Deeper Understanding of Transformer for Residential Non-intrusive Load Monitoring

Transformer models have demonstrated impressive performance in Non-Intrusive Load Monitoring (NILM) applications in recent years. Despite their success, existing studies have not thoroughly examined the impact of various hyper-parameters on model performance, which is crucial for advancing high-performing transformer models. In this work, a comprehensive series of experiments have been conducted to analyze the influence of these hyper-parameters in the context of residential NILM. This study delves into the effects of the number of hidden dimensions in the attention layer, the number of attention layers, the number of attention heads, and the dropout ratio on transformer performance. Furthermore, the role of the masking ratio has explored in BERT-style transformer training, providing a detailed investigation into its impact on NILM tasks. Based on these experiments, the optimal hyper-parameters have been selected and used them to train a transformer model, which surpasses the performance of existing models. The experimental findings offer valuable insights and guidelines for optimizing transformer architectures, aiming to enhance their effectiveness and efficiency in NILM applications. It is expected that this work will serve as a foundation for future research and development of more robust and capable transformer models for NILM.