A very nice tutorial of paper writting for TOEFL

Welcome to the TOEFL-Prep Writing Practice Site

http://lrs.ed.uiuc.edu/students/fwalters/toeflwrite.html

ssh refused to visit

If you got this problem ,first check if both computers have installed ssh.
This stupid problem wasted me few hours.

vncviewer: keyboard mapping problem

If you encounter a problem of keyboard mapping when you use the vncviewer,
the solution is to add "export XKL_XMODMAP_DISABLE=1" to the file "~/.vnc/xstartup"  on the server which looks like:

"
#!/bin/sh

export XKL_XMODMAP_DISABLE=1

xrdb $HOME/.Xresources
xsetroot -solid grey
#x-terminal-emulator -geometry 80x24+10+10 -ls -title "$VNCDESKTOP Desktop" &
#x-window-manager &
/etc/X11/Xsession
"

Of course, you have to restart xserver to implement the changes.

Opencv 2.3 on Ubuntu 9.10

The ubuntu 9.10 is not supported by ubuntu community any more. To use apt-get,
you have to manually edit "/etc/source.list" file and replace "archive" with "old-release".

The Opencv 2.3 need a cmake 2.8, buth ubuntu 9.10 only has cmake 2.6, so when you compile the opencv 2.3 the cmake gives you errors and warnings such as "incompletely configuration".

What you need to do is downlad cmake 2.8 and install it.

URG-04LX-UG01 problems and solutions

Recently our group got a urg laser which has a usb connector. It took me about two days to figure following problems out:
 
1. Power. The laser comes with a dual usb connector. From the urg website, it says the urg needs two usb port to get enough power (>500mA). I have tried every pairs of usb port. Neither of them work. The possible reasons are: the laser is damaged, the cable doesn't work, or the power from pc usb is not enough. I simply use a single usb connector from my mp3 to replace the dual usb port, then the laser is surprisingly working!! What can I say. Dual port don't work, single port works fine! If you have similar problem, then you can try this solution.

2. Library. Now the laser can work well with XP system after installing the driver. However, the library got some problems when I compile them, such as can no reference to 'floor'. I google the solutions and find one nice patched urg library which works fine for Ubuntu oneiric: http://bazaar.launchpad.net/~ubuntu-branches/ubuntu/oneiric/urg/oneiric/revision/4?start_revid=4 You can download the tarball of the urg library and compile it. That works great on my ubuntu machine.

3. Urg program samples. The sample programs also get some problems, such as "undefined reference to" blabla. The solution is very simple: rewriting the Make file (for C++ urg_sample) as : CXXFLAGS = -g `urg-config --cflags` `sdl-config --cflags` LDFLAGS = `urg-config --libs` `sdl-config --libs` LDLIBS = -lc gdScanSample: gdScanSample.cpp g++ -o gdScanSample gdScanSample.cpp $(CXXFLAGS) $(LDFLAGS) $(LDLIBS) clean : $(RM) *.o $(TARGET) .PHONY : all clean


Now, everything works perfectly. Enjoy!

Google, what are you going to do with the blogger?

Now the google has the google+. How about the Blogger? It's even harder to access the Blogger from the homepage of the Google. I couldn't find it. The only thing about the blog is the blog search which is useless for me, because I don't want to search my blogger which is ridiculous. The only way left is to type the www.blogger.com instead of the www.google.com.

such that vs. so that

so that focuses on a purpose.

such that focuses on a consequence.