Category Archives: Thoughts

[Duolingo Introduction] Part 1: From Captcha to Digitalizing the books


Duolingo is a startup that focus on language-learning. And it’s a nice one.

Being constructed by the founder of Re-captcha, Duolingo also shares the vision of utilizing the power of community to make the world better. So, before the story of Duolingo, I’ll tell you the tale about how  Luis von Ahn creates Recaptcha.

recaptcha-exampleHave you even registered in any website? Did you see little words that you must type to prove that you are not a auto-robot? “If you type the weird words in the images right, you may get in”. If you saw it, you know what a Captcha is. It’s a simple mechanism – based on the fact that no matter how far technology goes, it’s still nearly impossible for a machine to tell a bad writing from random images with thousands of senseless dots.

Ok, but have you ever asked yourself, why sometimes, you must type 2 words instead of 1?

The reason is simple. When Luis sees that we all must type Captchas everyday, he wants to make it more useful.  He told himself: we still have lots of books/ materials in paper form. If we scan them, they still be in pure image form – we won’t be able to search them like a text ebook. The current technology doesn’t allow machine to translate from image to text accurately. But what if people can help in the process?

So Recaptcha was born. Among 2 word-images Recaptcha gives you, it only knows exactly 1 word. If you type that word right, Recaptcha will recognize you as a human and let you in. And yes! Because you type one word right, the second word should be right too! You just translate an image to a word!

missing you

The result is that a lot of books in Google Scholar is digitalized that way.

Thinking of The End

Steve Jobs

/* This post was written after the author complete reading the book about Steve Jobs by Isaac Walterson */

I never met Steve Jobs.

Only knowing him through the articles, the books,  and the news… I never have a chance to meet him in person, though I’d love to. An empowering leader, a great visioner, and a wit marketer… people even say he changes the world.

People also say he can be a lot selfish, hurtful, and rude. He can focus on the work through many days, as well as, be able ignore all the things he doesn’t want to see. Even his children.

He’s a man of complicated.

But even Steve Jobs, the Great one, can be forever. No matter how much money he had, how much famous he was, no matter how many doctors he called, in the end, he still fell before death.

No, I don’t want to talk about the metaphor such as: his achievements lives through… I just want to say about the fact. He was dead – no longer with us. No more. no less.

Walter Isaacson wrote a good book. Though I doubt that he has a subjective view about Steve… I must admit that the lines Walter writes about the last days of Steve… is very … well, impressive.

Impressive – in the end, such a great, vicious man, fears that “his children will mis-understand him”. He called Walter to write that book for him just for that reason. Well… Someone who can ignore the world to do what he thinks right, in the end, fears about what people say about him…

Even the prideful Steve Jobs, the cold-blooded man… in his last moments fears his children misunderstand him. That impress me more than anything in his best product collections

People are Subjective. We are subjective.

In spite of that, I somehow, share his feelings. Maybe in the end of his life, he could find peace among his dearest ones.

It’s important to take break, once in a while

“It’s sunny today, and the road is better.”

When long is the road, and it seems there’s no time to stop.
Try to take a little break, every time you have a chance
Because its value is invaluable.

[youtube=]  đến lúc thả diều rồi

Hope every one have a good time this weekend.

Don’t lose the ability to be surprised


Any fair-experienced CSS developers know that, if we want to be sure that a parent-div truly contains a child-element, we should put “overflow:hidden” in the parent div.

I was told that, too.

Ok, that solved the problem. And we continue going without truly knowing the reason “WHY”?

“Don’t fix what ain’t break” – people say.

In fact, I’m type of people who don’t like to invest time into things that aren’t useful. So I accept that trick as it is. Until today.

I was surprised (or remember that I was surprised) – like the first time I heard the trick. It took no more than 10 minutes to find an answer… but the question is that WHY I didn’t ask that question any sooner. How can I let the “magic” slip without wondering???

I suddenly remember a lot of other things that I take for granted. When I first come to this field, everything is new and shiny. After a while, things get normal bit by bit. And gradually I forgot my ability to wonder.

I remember the time when I was assigned to do OAuth 2.0 for a Facebook application. Instead using a library, I “silly” re-wrote the whole authentication process by Servlet/ HttpRequest & Response. By now I’m nearly sure that there must be pre-built library to do that thing somewhere. Whatever, I don’t regret. The time I put in studying how OAuth 2.0 works let me confidently say that I fully understand it, and I can (and did) manually write authenticate process for both Twitter & FB… They are all HTTP requests, basically.

What’s the way of your choice: learn just enough to do things – or learn intensely to truly understand how things work?

P/s: I have some ideas about “Key Concepts” (to overflow:hidden, it’s Document flow). But this post’s long enough.

Split the way


Dear my friends, fellow programmers & readers,

Thank you all for supporting my blog for a whole year. Your encouraging helps me maintain this blog, since I feels it’s useful to others.

The following lines was written, at the beginning of this blog:

As its name implied, in this blog I am going to share about my experience with technology and innovation. Just one of thousand blogs out there, I know. Thousands of blogs are thousands of views: this blog is my view, and if you like or dislike it, I’m more than pleased to discuss things out.

Truthfully saying, I didn’t follow the rule well. “Technology & innovation” is not a good description for this blog. After a while, it becomes more & more like a group of simple programming articles. So things must change, to reflect what it really is.

I decide to setup a new blog, which is at . I will dedicate my explorer spirit for new technologies, & innovation methods there. This blog will remain as a record for my journey as a programmer.

A message from Wikipedia

Source: Wikipedia

From Wikipedia author Aniruddha Kumar

I can speak Hindi, Urdu, English, Sanskrit and Moroccan. But I can’t read what’s on my computer screen.

Being blind online means I have to listen to all the text — including ads. That’s one of the reasons I rely on Wikipedia so much. It doesn’t waste my time by making me sit through advertising like almost every other website.

Wikipedia is one of the most beautiful things in the world. It takes the concept that everyone has a basic right to information and makes it into something real — a tool that’s free for anyone to access, even blind people like me, and completely neutral.

When I first found out about Wikipedia — that I could be part of this amazing collective project — I knew I wanted to contribute. And I’m asking you to join me.

Will you support Wikipedia with a gift of $5, €10, ¥1000 or whatever you can afford?

Wikipedia gets almost as many visitors as huge sites like Google and Facebook, but it operates on a tiny fraction of their resources. And it depends entirely on donations from readers like you.

Instead of ads, Wikipedia has a community of millions of volunteer editors double-checking every word and citation. I’m so grateful for them – their work makes learning online possible.

The philosophy of Wikipedia is to make a sea from drops. And it applies to everyone who contributes, whether a few edits or a few dollars.

Thank you,

Aniruddha Kumar
Wikipedia Author

The message says it all. Most of the time, web pages are filled with advertisement. It only make us annoying, but with Aniruddha, it cause a lot of problems.

And I also hope for a free Wikipedia.

Sometimes it’s happy just because you have a work


Happy working

Don’t know why I spare the small time to write this post.

Sometimes happiness is hard to explain. Having a work, which you loved to do (or simply just because you do it well) is really a bless.

It’s kind of playing a game, but more… you have a product at the end. You know your hard work will yearn good results. You know that all your efforts are not for your own richness or pleasure. You know that what you create will last.

Hope you all find a good work. :)


Books – Cover, content and the presentation

/** Vietnamese: Cảm nghĩ khi xem bộ sách viết về kinh tế “Chào mừng 1000 năm thăng long – hà nội **/

Today I have a chance putting my hand on a series of Vietnamese economic books. That series is made to welcome the 10 centuries ceremony of Hanoi – Vietnam Capital.

I don’t have much time reading all the things. Skimming my way through the book, I feels that most of it are paragraphs with facts, bullets, numbers and so on… As far as I can tell, there’s no sharp argument or interesting question. If I am an economist, I may guess out the meaning of all those figures. But I’m not, so I’m lost.

The authors are all famous. They are professors, doctors… And to receive the task to write a book series for the most important ceremonies in this century… I don’t think they lack knowledge. But I must say that they failed to transfer their knowledge into their books.

When I first saw the books, I thinks positively: they are made to give us – normal citizens – the overview of the nation we live. But this series doesn’t seem to care about normal readers. Who will buy those books? Economists PhD & Master?

There’s a reason that Thaksin buy cell-phones for Thailand’s farmers. There’s a reason that Fukuzawa Yukichi writes lines that inspired a generation of Japan. Information are important. It’s important not only about what’s their content – how the information are organized & presented also matters much.

I still remember the feeling while reading Fukuzawa Yukichi, with all his enthusiam & efforts put in his works. The good books are the books which create the problem in readers’ head, and make them think. Only by thinking may the reader remember the content. Otherwise, it’s no difference to listening morning news.