Overview and Intuitive Understanding Hidden Markov Model (HMM) is a class of probabilistic models used to model and infer system evolution processes in situations where “states are unobservable”. The core problem it solves can be summarized in one sentence: When the true state of the real world cannot be directly observed, can we still infer the most likely internal state change process of the system based solely on the observed phenomena?...
Starting with an Intuitive Problem When processing audio, speech, or other time series data, we will almost certainly encounter this problem: if two signal segments are similar in “content,” but not consistent in the speed of time progression, can we still judge that they are similar? This problem is very common in real scenarios. For example, two people sing the same melody, but one sings faster and the other slower; students may slow down due to hesitation during sight-singing, retreat and re-sing after making mistakes, or suddenly accelerate at certain positions; the same sentence is spoken by different people with different speaking speeds and different pause patterns....
Preface During my university studies, sight-singing and ear training was a course that gave me quite a headache. While the course itself is very fundamental, it is not easy for many music majors, and I was one of them (laughs). As I progressed through my studies, I gradually discovered a significant problem with sight-singing and ear training when practicing independently: students often find it difficult to notice their own mistakes in a timely manner....
Overview When Claude Code was released in May, it didn’t catch my attention initially. However, it has now become an indispensable coding assistant that I can no longer live without. I would call it the most powerful coding assistant available. Unlike Copilot, Claude Code is a CLI tool—a command-line interface tool. This is great news for those who love command-line tools, but might be somewhat challenging for “point-and-click” users. Overall, CLI tools inherently have advantages over Copilot in development assistance....
For the past six months, I’ve been following the tutorials from fernvenue’s blog posts, “Trying OpenWrt on the NX30 Pro” and “Configuring Policy-Based Routing on OpenWrt”, to set up a similar configuration at my place. This has made my internet experience smoother and my network traffic management clearer. However, I once encountered an issue where PBR wouldn’t start after reinstalling OpenWrt. The download and installation of PBR went fine, and it would even start correctly without any profiles enabled....