#### shivajikobardan

- Oct 21, 2021

- 39

- Joined
- Oct 21, 2021

- Messages
- 39

**Highly reputed source(International)-:**

The compartmental analysis figure is the diagram that I want to translate to differential equations and eventually analog computer.

This is from

This book. IDK about the author, but I bet that this is extremely reliable compared to the materials locally available and written by local authors. But it doesn't tell which equation it is modeling, so I am not 100% sure about it.

It has problems as well-:

It doesn't use negative for K12 And idk why is it using negative for K23.

**Less reputed source-:**

This is pretty ambiguous, their equation and figure don't even match.

**Highly reputed source(LOCAL)-:**

If this source is correct, I don't understand how is it correct?

**My thoughts about sign what they should be-:**

If the arrows are coming towards the block in consideration, add + sign else add - sign.

For eg-: consider x1 block, then we find x1', for that + will be what comes inside i.e K21*x2, and - will be what goes outside ie.K12*x1.

**My Teacher(He hasn't written any pdfs)-:**

He says "some books have written plus(in K21) while some minus I am not sure what it is actually." He is not the one who will check my final exam paper. We don't know who will check it or who checked it.