Xianfeng Songs blog

I am getting heavier and heavier! So, on Monday, I decided to start my workout plan. On Tuesday, I bought the gym pass and also one year of locker. On Wednesday, I started my workout plan and run for half an hour. Today, I swam for 10 loops (Don’t know the distance for one loop. ) The strength of these workout has not reached my limit. I wanted to make my body get used to these workouts gradually.

I would expect these workouts would drain me of energy and hopefully by doing these, I would lose weight! On the contrary, to my surprise, the workouts refilled me energy! I usually get tired in the late afternoon and can not do much in the evening. But yesterday and today, I could focus and do much more things in the evening without feeling tired!

Writing ajax is a pain in the ass. But GWT allows you to create ajax pages in java language. Although Java Script has similar syntax as Java language, several inherent features (such as no strict type…) in Java Script make it more prone to error and difficult to debug. The incompatibility between different browsers also makes ajax pages more complicated. GWT uses Java as the base language and recompiles it to HTML and Java Script, which can solve the above mentioned problems and make the development processes much easier. The followings are the quotes from GWT homepage:

Google Web Toolkit (GWT) is an open source Java software development framework that makes writing AJAX applications like Google Maps and Gmail easy for developers who don’t speak browser quirks as a second language.

GWT lets you avoid many of these headaches while offering your users the same dynamic, standards-compliant experience. You write your front end in the Java programming language, and the GWT compiler converts your Java classes to browser-compliant JavaScript and HTML.

If you are like me, the alumnus of Peking University, you should be able to join the Peking University network on Facebook. Here are the steps:

(1) You should first goto www.pku.org.cn to register as an alumnus. Thus you will be given an email address with the domain name pku.org.cn.

(2) Goto the Networks’ pull down menu, you should see “join network” and click it. After entering the given email address on the page, you are ready to go.

Fanglei today passed her defense. Congratulations to her! We old friends gathered together at China house for the dinner in her honor.

The conjugate gradient method is an algorithm to iteratively solve particular systems of linear equations, namely whose matrix is symmetric and positive definite. The biconjugate gradient method provides a generalization to non-symmetric matrices.

LU decomposition: An invertible matrix admits an LU decomposition iff all its principle minors are non-zero. For a matrix A of n by n, I is any subset of {1,..,n}, then [A]_{I,I} is called a principal minor. A non-invertible matrix can sometimes have LU decomposition.

If a matrix is hermitian and positive definite, the matrix can have Cholesky decomposition (A=LL^{*})

Suddenly I found I became a Facebook addict. There are several things I need to do to control it:

(1) Put a note in front of my screen saying that checking Facebook twice per day is enough!

(2) For something need to be done on Facebook (like managing the groups), put it on todo list!

I have been using my current macbook for about a year and nothing seriously has happened on it. But yesterday afternoon it randomly shut down while on battery. There was no warning signs at all. I lost all my unsaved stuff. After its shutdown, it could not be turned on until I plugged in the power. It happend again yesterday evening in the exactly the same situation.

After these happened, I did two things and hope they will solve my problems.

(1) Reset SMC (System Management Controller) by following this article.

(2) Recalibrate the battery

I will give update on this issue.

GrandCentral beta (acquired by google in July)

The central idea is very cool: to become the gateway for all your phone services. The customer can get a number for the whole life[1]. The phone number is free and can be redirected to any of your current phone numbers (you can choose to redirect to different number depends who are calling you). You can make calls through the website. You can also place a small widget on any of your webpages to let use call your grandcentral number (while your number stays private).

You can reach me by using this widget! Please don’t call me if you don’t have questions.

[Note 1]: After google acquired GrandCentral, previous customers were reportedly removed the number they had owned

I finished reading this book today. The last half part of this book is not exciting at all. The author turns to how to successfully run a e-business.

We can now redefine the 4 steps in the context of e-business:

First step: D is for Definition. Find out what you can do for e-business. Be ambitious.

Second step: E is for Elimination. Eliminate the tedious work. Try to outsource as many as you can, effectively.

Third Step: A is for Automation. You should build an automated system for your system.

Fourth Step: L is for Liberation. Enjoy your life!

Personally I don’t like this half which is not as inspiring as the first half. The author should do some elimination on this part! Anyway, this is only a best-seller. What can you expect!

I have heard ecto as a great blogging client. But today’s experience is frustrating. I tried to get ecto working with my Wordpress(version2.2), but kept getting the error message:

“A list of blogs could not be retrieved! Please verify the account you created. “

In the FAQ session of ecto forums, an article explains the possible way to get around the same problem. The article gives several suggestions (note: not solution). None of these suggestions works!

BTW, Ecto looks really great! And it works seamlessly with blogger.