How to write the subtitle of the thesis topic?

The subtitle of this topic can be written like this:

1, the subtitle should be short and clear, highlighting the core content of the paper, generally around 10 to 15 words.

2. The subtitle should echo the main title, and * * * reflects the theme and research direction of the paper.

3. Subtitles should avoid using too many modifiers and adjectives to avoid confusing readers.

4, subtitle should avoid using unusual abbreviations or technical terms, so as not to affect the reader's understanding.