Why quaternions in neural networks (NNs)? Are there quaternions in the human brain? “No” may be an ordinary answer. However, quaternion NNs (QNNs) are a powerful framework that strongly connects artificial intelligence (AI) and the real world. In this article, we deal with NNs based on quaternions and describe their basics and features. We also detail the underlying ideas in their engineering applications, especially when we adaptively process the polarization information of electromagnetic waves. We focus on their role in remote sensing, such as Earth observation radar mounted on artificial satellites or aircraft and underground radar, as well as mobile communication. There, QNNs are a class of NNs that know physics, especially polarization, composing a framework by fusing measurement physics with adaptive-processing mathematics. This fusion realizes a seamless integration of measurement and intelligence, contributing to the construction of a human society having harmony between AI and real human lives.

中文翻译：

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四元数神经网络：结合物理的智能框架[超复杂信号和图像处理]


为什么神经网络 (NN) 中使用四元数？人脑中有四元数吗？ “不”可能是一个普通的答案。然而，四元数神经网络 (QNN) 是一个强大的框架，可以将人工智能 (AI) 与现实世界紧密连接起来。在本文中，我们将讨论基于四元数的神经网络并描述它们的基础知识和特征。我们还详细介绍了其工程应用中的基本思想，特别是当我们自适应处理电磁波的偏振信息时。我们重点关注它们在遥感方面的作用，例如安装在人造卫星或飞机上的地球观测雷达和地下雷达，以及移动通信。在那里，QNN 是一类了解物理学（尤其是偏振）的神经网络，通过融合测量物理学和自适应处理数学来构建框架。这种融合实现了测量与智能的无缝融合，有助于构建人工智能与人类现实生活和谐相处的人类社会。