It is quite annoying that usb does no longer work out of the box for Virtualbox with ubuntu host. The issue seems to affect multiple Linux distros. As of version 5.1.18, it seems that the bug is still not fixed. The workaround is not very complicated. But it is a nuisance nonetheless. Update: If…
I am using more and more beamer this year. Since I used linux, I used to use evince to display my slides. But in my last class, I would like to write something on the slides and I was not prepared for that. My laptop is a nice good old X230t with a stylus on it….
Backstory It started that I would like to have my students to vote for their peers’ presentations. And I don’t like to do it the old fashion paper way. I thought of using some commercial products. But since I was reading a little bit JavaScript couple weeks ago, I guess it probably would be a…
This is a re-post of a blog post I wrote for my department blog couple years ago. I just read it again and I found it still relevant. For those of you who have been to my office or have taken my classes will know that I am a big Linux fan. I started to…
I recently got a used X230 tablet and tried to have some fun on it. StarCraft runs well with wine but cannot run on full screen. One possible solution is to open another X server following this post. But I need some tweaks for 14.04 and for touch and stylus to work. First, one needs to add Section…
There is no excerpt because this is a protected post.
I am in Shanghai a couple days and it is quite inconvenient with many websites blocked. I heard about “breaking” the wall but I didn’t realize it is quite fast and easy. All one needs is a software called goagent. It takes advantage of the google app engine. Here, I will assume that ones already…
A simple simulation of M/M/1 queue with Matlab. The distribution of the number of “packets” in the system is computed and compared with the theoretical result. delta=0.1; % simulation step in sec lambda=0.1; % arrival rate in packets per second mu=0.2; % departure rate in packets per second rho=lambda/mu; M=50*3600/delta; % number of simulation step…
Below is a simple Matlab code to simulate a Poisson process. The interarrival times were computed and recorded in int_times. The times are then grouped into bins of 10 seconds in width and the counts are stored in count. lambda=1/60; % arrival rate per second (1 minute per packet) T=10*3600; % simulation time in second…
As a cantonese from HK, I didn’t know how to “type from my mouth” as a kid. I learned Cangjie during high school but I have never become really proficient with it. Chinese is not exactly a phonetic language. But when I write IM, email, or just blog in Chinese. I found it much better…