The aim of this post is o summarize linear system definitions such as admissible, causality, time invariance relaxed and impulse function. For Korean version please refer to here . If you can understand the following terms, you can skip this post. U and V are input and output space which is set of admissible signal The picture below is the main content will explain linear system definitions. Now let’s start step by step. Linear System Definitions Space The space comes up which is a very important definition in linear system and linear algebra .Here, I would like to give a rough outline rather than a mathematical point of view. Let’s think about it simply. Several experiments were conducted. In order to organize the experimental results, the input and output data are separately collected and organized. where, collected input data is called input space and output data is output space. it is annoying to put it in words, so we can express it mathematically as follows. For ...