Showing posts with label Education. Show all posts
Showing posts with label Education. Show all posts

Wednesday, March 4, 2009

Fast Fourier Transform (FFT)

Suppose you have a time series data of something (some quantities given as a function of time), and would like to know the frequency of your data, you may use Fast Fourier Transform (FFT).

Figure below shows a time series of something:
As illustrated, the values repeat itself at a constant rate (it follows a cyclic pattern), and along each larger cycle, there are fluctuations that repeat itself at a shorter interval and of lower amplitude.
So you may expect two dominant frequencies to be obtained out of FFT.

You may perform the FFT by using Excel, however, problem with excel is you are subjected to the limit of maximum 4,096 data points.

Luckily there are always good-hearted people out there trying to help.
Here I found one freeware by Paul, which allowed me to process more points.

Via his software, here is the result of the FFT:
Two dominant frequencies are found just as expected : )
Thanks Paul!

Sunday, February 24, 2008

The art of study

In study, just focus on what you can learn and forget about what you can get (the score), then, eventually, your study will be meaningful.

Wednesday, September 26, 2007

Kalau Tak Kenal Maka Tak Cinta

It's written in my profile that my Favorite Books are Thermodynamics, Fluid Mechanics... some might think "arhh! What a tech geek!" or "Just kidding right? who on earth would find those books interesting?" It's normal for ppl to think that way as the titles that ended with "ics" are usually serious stuffs and does cause headache to some people.


The fact is, if this happen to you when reading the “-ics” stuffs (you feel headache), it’s because you failed to relate what you read (the contents) to the real life phenomena. That is, when you can’t see the physical meaning of what you read, and are trying to memorize each fact, statement (of theorem) or equation, blindly.

This happened to me when I’m doing my certificate (General Mechanical) in polytechnic, my “study” is nothing more than mere memorization. I managed to score good grade though (very good indeed), but found my study stressful and boring.

I realized there must be something wrong in the way I study (in spite of my good grades), because the “knowledge” that I acquired is mere memorized facts; they can’t be applied to solve the real life problems as there are no real understanding.

So when I’m doing my BSc, I’ve resolved to go for knowledge, not grade. When reading, I try to visualize (or you may call it using the imagination) the subject matters in order to see its physical meaning and try to relate it to the real life phenomena. For instance, when I read the definition of density, I won’t simply memorize the fact density equaled to mass per volume, instead, I would try to visualize there being some objects that is containing in a volume. This is what I mean by seeing the physical meaning. Then I would try to visualize how molecules of water containing in a volume are more pack to each other when compare to the molecules of oil. This is what I mean by relating it to the real life phenomena. Once you “see” the subject matters CLEARLY and EXACTLY (in your mind) then you can say you have learned it.

So the “actual” study is reading exercise that involves a lot of mind activity like this. Memorization that didn’t involve the mind to venture deep into the subject matters is not real study, because there is no real learning take part – you just memorized some facts but you didn’t see the subject matters yet!

There is a malay saying:

“Kalau tak kenal maka tak cinta”

This is true in almost all expects, including study. So don’t worry if you think that study is boring, or that you don’t like the courses you are taking, it’s just that you haven’t get to know your subject matters well. All you have to do is to put efforts into knowing your subject matters, once you did, you’ll find them fascinating! I know how frustrating and how interesting study may be, because I’ve been through the “using memorization” and “using imagination” stages, so I know.

So this is just a sharing based on my own experience. By the way, how about stuff like this:

…In daily life, the concepts of Mr. Right and Ms. Right are also idealizations, just like the concept of a reversible (perfect) process. People who insist on finding Mr. or Ms. Right to settle down are bound to remain Mr. or Ms. Single for the rest of their lives. The possibility of finding the perfect prospective mate is no higher than the possibility of finding a perfect (reversible) process. Likewise, a person who insists on perfection in friends is bound to have no friends.

Yunus A. C. and Michael A. B. “Thermodynamics”, Fifth edition.

Are them really boring stuff?

Fly

One day a man saw an elder who already (looks like) eighty something but is still working. This filled the man with wonder, so he asked the elder:

“You are so old already, why are you still working?”

The elder replied,
“Have you ever see birds? Did birds ever quit flying?”

The words of wisdom given by the elder had deeply touched the man… it had touched me too, when I heard the story shared by the man in this evening’s course that I attended.

I have a similar story of my own, in a less-wisdom version:
One day, a student came into my office room while I am reading a book. He asked: “Sir, you are already a lecturer, why are you still studying?” I smile (I know this don’t happed often, I guess it’s the student’s lucky day) and explained to him that being an academician, learning is a life-long matter bla bla bla and bla bla bla… (Hope I don’t put the student into sleep) But I know how I should react to that kind of question now, so that I sound better and wiser - like a man with wisdom : )

Anthony Robbins, a renowned life coach once said that:
“The only way we are happy in our life is when we are growing”

This is very true to me, no wonder I love learning so much (not limited to academic stuff). When I’m learning something, I am growing, and that is where the enjoyment comes.

I really feel pity for students who don’t find study enjoyable; I think the reason that they don’t is because they don’t study for grow, but for exam and grade. Well, I used to be a student before, I know how terrible it is to have to force ourselves memorizing facts and steps instead of to perform what a real student is suppose to perform – study and grow!

A bird that has stopped flying would not travel far.
So be wise friends, find the ‘wings’ and ‘fly’!
This will keep us growing…
and to
Enjoy this life better.