Thank you.
I know that way to say but you can see sometimes such as in a scientific paper, people write 0.5 hour, 1.5 hour etc.
Can you guide me?
Personally, I would consider anything that included a decimal portion of an hour to be followed by "hours": 0.5 hours, 1.5 hours, 1.1 hours, 0.0 hours, even 1.0 hours. If it were were written in a fraction, though, I would expect anything above 0 and up to 1 to be "hour": 1/10 hour, 1/2 hour, 3/4 hour, 1 hour, 1 3/4 hours. (I would read these out loud as "one tenth of an hour", "a/one half-hour", "three-quarters of an hour", "one hour", "one and three-quarters hours").
In timekeeping (such as timecards), it's common in AE to see "hr." rather than "hour" and "hrs." rather than "hours".