Xianfeng Songs blog

I really don’t know! Life sucks, and I just desperately want to get out!

Facebook can also be addictive. I found myself constantly check the facebook everyday. It costs so much of my precious time. You know, the feeling of being connected to people is really really good.

This article Facebook labelled a $5b waste of time proved my concern.

Zheng and Mengmeng are going to leave bloomington on the coming Monday and we held a farewell party for them this evening. Zheng is going to Washington for his experiment and Mengmeng is going to school in Georgia. I took some crappy pictures during the party using my iphone.

My wordpress recently had an annoying problem: whenever I submitted a new post, it would complain the errors with the xml-parser stuff. So I decided to upgrade my wordpress system. The upgrade process turned to be very easy and took me only 5 minutes.

Step 1: I need to download the newest version from the website: http://wordpress.org
Step 2: Copy the new files into the old wordpress direction. Since I installed some plugins on my old system, I need to keep the wp-content directory.
Step 3: Run /wp-admin/upgrade.php and follow the instructions.

That’s all!

In order to increase your productivity, you have to eliminate your bad habits which waste lots of your time but contribute to your productivity very little. Here is my not-to-do list:
1. Do not check email regularly! I spent way too much time on checking email.

2. Do not spend too much time reading news.

3. Do not spend too much time on trivia things. Instead, focus more on your main goal.

This post is inspired by the blog post: The Not-To-Do List: Bad Habits to Stop Now

My way of doing this is to first assume that the limit does exist and the value is c.

Then when n0 is big enough, Sum[n^p, {n,1,n0}]/n0^{p+1} = c is a very good approximation. Thus,

Sum[n^p,{n,1,n0}]=c n0^{p+1} (*)
For the same reason,

Sum[n^p{n,1,n0+1}=c (n0+1)^{p+1} (**)

From equation (*) and (**), you can solve that c=1/(p+1).//Done

It is actually more difficult than what you think.

One naive algorithm is:
(1) Think of the sphere as the earth and give it a fixed north pole and south pole and a fixed arch as zero longitude.
(2) Choose a uniformly distributed angle between [0, 2pi] as the longitude of the new point and a uniformly distributed angle between [0, pi] as its latitude.

You might think, through this method, the chosen point is randomly distributed on the spherical surface. However, it turns out this method is wrong! It would give more probability on the poles than on the equator.

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How can I control it? It’s just like sky falling down and everybody is going to die! I am just lost, and don’t know where to go.
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But wait a minute, you’ve gotta think about good things! What’s your goal? What’s the meaning of life?
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Anyway, happyness is from your inside!

When you don’t want to get things done, there are two excuses:
1, You are not confident with what you are doing
2, You are not being responsible to yourself

I list the first one because I want to give myself a better excuse when I don’t want to get things done. Really, there is only one excuse!

You have to keep up with the changes. Otherwise, life will be miserable.