Can I patent a model that I described in a paper or that I adapted from a model proposed by someone else? Is a patent more prestigious than a paper? Academic papers in engineering sometimes propose a new model to tackle  prior difficulties. These proposed models are not usually patented. For example in experimental papers and many power electronic papers, the models are fully available.
I have a published work that proposes a new model, but it is pure computer simulation and math. 

So, my questions:


Can I patent my own published paper?
Can I use others' paper and patent their idea? (specifically
experimental for papers)
If the answer of 1 or 2 is not, how many modifications do I need to
apply in my model be able to patent it?
If I have an original idea to propose a new model, what should I do then: A patent or good rank ISI paper?
You don't patent papers. You patent ideas.

You can't patent other people's published work because their published papers are clear evidence of prior art.

Why do you want to patent a computer model in the first place? Why do you want to restrict people's use of it? How lucrative will it be?