reasons why the prediction is inaccurate

Today, I read the theoretical part of NMR logging and T2 distribution. With the combination of the parameters I get, I made a conclusion which may be helpful for my further research.

Summary:

As we can see in the picture I plot, different combinations of three parameters mean different physical properties underground.

But usually, one parameter should mean one kind of information in most ann models. That is why the performance of ann model is not good enough to predict these parameters from my perspective.

I also try to predict 6 parameters at one time, but since only eight combinations of them have physical meanings, it is still very hard for the ann model to identify them from all of the possible combinations.

What I should do next may be:
1. find more logging data which are related to T2 distribution and they should be normal and cheap, but maybe 16 are enough if I can find other better ways.
2. change the parameters I get into other forms, such as multiply miu and alpha, but the separation of them will be another problem if the prediction results are good.

Next week, I will do as above one by one.