Difference between consider and concern
I would appreciate if you could let me know the difference.

I think basically both of them just mean ``think". However, the former is neutral
and academical, whereas the latter sounds like worrying some unpleasant problem in a usual life.

For example, consider a mathematical problem, consider the performance of an algorithm, etc.
On the other hand, concern an illness, concern a lack of money, etc..

Am I right?

Question

Difference between consider and concern
I would appreciate if you could let me know the difference.

I think basically both of them just mean ``think". However, the former is neutral
and academical, whereas the latter sounds like worrying some unpleasant problem in a usual life.

For example, consider a mathematical problem, consider the performance of an algorithm, etc. 
On the other hand, concern an illness, concern a lack of money, etc..

Am I right?

Answer

You understand "consider", but the verb "concern" by itself is not used in the way you describe. It is reflexive, such as "I will concern myself with this problem", meaning it is important to me, or transitive, to make someone worried, such as "the noise concerned her".

Answer

Actually, "concern" can also mean "about."  Example:

This concerns our office in China.

The other meaning of "concern" is, as you suspect, to worry or be anxious about.  Example:

She is concerned about global warming.