Epenthesis strategy follows "preserving maximally" principle, and inserted vowel types reflect human beings' perceptual ability.
增音方式体现了音节的“最大保留”原则，而增音的种类符合人类的语音感知能力。
2
More practical ray tracing methods currently include the wavefront method, the shortest path method, the travel time epenthesis method, the eikonal equation finite difference method, etc.