His Story

Wow, that is a long title. Yes, they are the famous two principles in Software Engineering I’ve learned when I was in ITB. It says that, the software you designed is stable, if in general

1. It will never enter a undesired state
2. If it unfortunately enters an undesired state, it will eventually back to a desired state later.

While it is realistically impossible to achieve the first goal, although software engineers are trying to reach it as close as possible, there are many ways to accomplish the second one. It sometime can be some procedures, which are what we called "backup plans"; it sometime can be some kind of self recovery mechanism; or, it can be proved that the software will eventually do something good. Here is the video version of the idea.

It’s a nice sunny afternoon in the library. So I tried to start a video chat to share this sunshine with her. However, she denied my request. She said that there is a limit on the bandwidth of 1GB per week with the broadband network in her residence.

Bandwidth, is a measure of the amount of data that can be transferred between computers in a network within a specific period.

I’ve been thinking about this for a while: Why do the Internet service providers want to limit the bandwidth? Well, the most reason I’ve heard is that they want to protect the network device from being overloaded and avoid other network users from squeezed out of the information highway.

Hmm, how can they do that by limiting the bandwidth? Let’s take an example in real world. Say there is a bridge on a river and people walk through the bridge from one side to the other side every day. Unfortunately there is a policy from the bridge owner that the bandwidth, the number of times one person allowed to walk through the bridge, is 10 times per day. Sadly, most people need to use the bridge several times only in the morning. It turns out that there are about 100 people walking on the bridge and each person go back and forth 10 times during that time. They don’t really need the bridge for the rest of the day except in the morning. Bridge is overloaded and few guys with bad luck fell into the river because of that.

I think, what the bridge owner really mean, is to limit the throughput.

Throughput, is a measure of the amount of data that can be transferred in a time unit between computers in a network.

It means that, if I am the bridge owner, I don’t care how many time you walk through the bridge everyday. But you must follow the rule that you are allowed to using that bridge for at most twice per hour! So no one will be waiting by the entrance and the bridge is always is good shape.

It’s the same for the computer network. Why can’t they just limit the throughput to, say 256kb per second? Doesn’t that make more sense?

 BTW, the new Windows Live Space is here. Xuan, your team is cool!

Per the post, here it comes.

Last week my brother got a job offer in Shanghai. The position is the same title as mine but it’s in a different product team. Congratulations to him!

What?  Don’t you know we are twins?

It turns out that the second beta of Windows Live Writer is released, so this post is just to give it a try. Update: If you have installed Bad Behavior in your Wordpress site, you will probably see a 403 error when publishing in WLW. Make sure you turn it off.

Today is a sunny day and we’ve spent whole afternoon on the first morale event since I came to the team - Picture Hunting. People were divided into 7 groups and were give a specification of 50 items. Each group wants to take 50 pictures inside the campus according to the specs, within a fixed amount of time. I think my group has done a good job. We first brainstormed on the specs and marked each item with possible location. Then we planned our route just to make it less time consuming. We’ve searched the garage, the soccer field, the people’s offices, etc. and we ended up with a bunch of interesting pictures. It was really fun.

Look what I’ve got:

(credit: popfly.ms)

Tell me, what do you see in this picture?

No clue? Take a closer look.

These are plastic bags.

There are about 60,000 plastic bags in the first picture. That is the number of bags used in the US every five seconds. Each plastic bag takes up to 250 years to decompose. (credit: chrisjordan.com)

Hey, buddy! How’s going? Yeah, I’m good here. Are you coming to Seattle to visit me sometime? OK, It is too bad that you don’t have vacation any time soon. Alright, just in case you are wondering how does it look like in WA, here are some high definition photos taken by Microsoft Research. Check them out.

BTW, don’t forget to scroll your mouse wheel to zoom in for more detail. =)

Tired of “history | more“? After you’ve type a bunch of commands under PowerShell window, simply press [F7] to trigger the history window. Never thought this thing can be so interactive. =)