Great blog post I came across.

As I was browsing around I found this post shared on Facebook - https://medium.com/life-learning/2a1841f1335d

Really great one. Got me thinking.
I will just put up the headings. Read the entire post at that link.

7 Reasons why you will never do anything amazing with your life

1 :: Because You Have Not Failed Enough

2 :: Because You Care What Others Think About You

3 :: Because You Think You Are Smarter Than You Are

4 :: Because You Don’t Read

5 :: Because You Lack Curiosity

6 :: Because You Don’t Ask Enough Questions

7 :: Because You Can’t Handle The Truth

Read the entire article here.

The orginal article here.

 

 

 

 

 

 

Modelling of systems

Modelling of systems is the first step in doing everything with the system.
If you have modeled a system, then you know exactly how the system is going to behave or not going to behave when it receives specific inputs.
So, if you don't know how the system acts then, there is no way you can use it and make it do whatever you want it to do. Everything system that we can interact with and understand how it is going to react is modeled in our heads. What you do not understand, you cannot model, or can we?!
There are 3 different ways in which systems are modeled.
One is from the laws of nature or white box modelling.
You know the forces acting on the system and you have the laws that these forces follow. Then, you know all you need to know.
Two is, grey box modelling.
Here we know the inner workings of the system partially. Some part we do not know. Its also called Semi-deterministic model.
Three is black box modelling.
Here, we don't know what is inside the system and its inner workings. The system is like a opaque black box which cannot be opened.  You just have places where you can give your inputs and places where you can see the outputs. From this we need to find out the relation between the inputs and outputs. Plus, the systems we usually encounter are dynamic, which means the way its going to act now depends on what input it was given earlier. i.e., we have to find the relation between the current output and current input, earlier input, earlier outputs.

Its clear to me that I myself am not clear with these things, because I cannot seem to be able to write with much confidence.

Signed Binary representation and mathematical representations

Two methods to begin with.
1. Sign/Magnitude representation
2. Ones complement method

Sign/Magnitude method : The leftmost bit is sign bit and remaining bits represent magnitude.
MSb is 0 for negative numbers and MSb is 1 for negative numbers.
Therefore we have +0 and -0. Not efficient.

One's complement method : the negative of a number is its ones complement(I expected something better).
therefore if 0 = 00000000, then 11111111 is -0. 1 = 00000001 and -1 = 11111110

Both these are not good enough, have drawbacks.Hence we have the Twos complement method.
That is negative of a number is its 2s complement(surprisingly simple).

Examples -  +1 is 00000001. to get -1, take ones complement : 11111110, then add 1 : 11111111
                  therefore -1 = 11111111

Same method can be used to convert -ve number to +ve number to find out the magnitude.
for example, the value of 10100011 is found like this -
take ones complement - 01011100
add 1 : 01011101. this has magnitude 93.
therefore 10100011 = -93.

Here too, the MSb points to the sign of the number.

Reference - http://www.swarthmore.edu/NatSci/echeeve1/Ref/BinaryMath/NumSys.html