SPECTra: Scalable Multi-Agent Reinforcement Learning with Permutation-Free Networks

In cooperative multi-agent reinforcement learning (MARL), the permutation problem where the state space grows exponentially with the number of agents reduces sample efficiency. Additionally, many existing architectures struggle with scalability, relying on a fixed structure tied to a specific number of agents, limiting their applicability to environments with a variable number of entities. While approaches such as graph neural networks (GNNs) and self-attention mechanisms have progressed in addressing these challenges, they have significant limitations as dense GNNs and self-attention mechanisms incur high computational costs. To overcome these limitations, we propose a novel agent network and a non-linear mixing network that ensure permutation-equivariance and scalability, allowing them to generalize to environments with various numbers of agents. Our agent network significantly reduces computational complexity, and our scalable hypernetwork enables efficient weight generation for non-linear mixing. Additionally, we introduce curriculum learning to improve training efficiency. Experiments on SMACv2 and Google Research Football (GRF) demonstrate that our approach achieves superior learning performance compared to existing methods. By addressing both permutation-invariance and scalability in MARL, our work provides a more efficient and adaptable framework for cooperative MARL. Our code is available at https://github.com/funny-rl/SPECTra.

LBC: Language-Based-Classifier for Out-Of-Variable Generalization

Large Language Models (LLMs) have great success in natural language processing tasks such as response generation. However, their use in tabular data has been limited due to their inferior performance compared to traditional machine learning models (TMLs) such as XGBoost. We find that the pre-trained knowledge of LLMs enables them to interpret new variables that appear in a test without additional training, a capability central to the concept of Out-of-Variable (OOV). From the findings, we propose a Language-Based-Classifier (LBC), a classifier that maximizes the benefits of LLMs to outperform TMLs on OOV tasks. LBC employs three key methodological strategies: 1) Categorical changes to adjust data to better fit the model's understanding, 2) Advanced order and indicator to enhance data representation to the model, and 3) Using verbalizer to map logit scores to classes during inference to generate model predictions. These strategies, combined with the pre-trained knowledge of LBC, emphasize the model's ability to effectively handle OOV tasks. We empirically and theoretically validate the superiority of LBC. LBC is the first study to apply an LLM-based model to OOV tasks. The source code is at https://github.com/sksmssh/LBCforOOVGen

Towards Efficient Formal Verification of Spiking Neural Network

Recently, AI research has primarily focused on large language models (LLMs), and increasing accuracy often involves scaling up and consuming more power. The power consumption of AI has become a significant societal issue; in this context, spiking neural networks (SNNs) offer a promising solution. SNNs operate event-driven, like the human brain, and compress information temporally. These characteristics allow SNNs to significantly reduce power consumption compared to perceptron-based artificial neural networks (ANNs), highlighting them as a next-generation neural network technology. However, societal concerns regarding AI go beyond power consumption, with the reliability of AI models being a global issue. For instance, adversarial attacks on AI models are a well-studied problem in the context of traditional neural networks. Despite their importance, the stability and property verification of SNNs remains in the early stages of research. Most SNN verification methods are time-consuming and barely scalable, making practical applications challenging. In this paper, we introduce temporal encoding to achieve practical performance in verifying the adversarial robustness of SNNs. We conduct a theoretical analysis of this approach and demonstrate its success in verifying SNNs at previously unmanageable scales. Our contribution advances SNN verification to a practical level, facilitating the safer application of SNNs.