2017-04-02

Wireless network keeps disconnecting problem

I encounter a Wireless network keeps disconnecting problem (often, frequently disconnection). My laptop is a DELL Precision 5510 with Windows 10, and my router is an O2 router (O2 box 6431).

  • Problem: When I use DELL Precision 5510 with Wifi with O2 router (O2 box 6431). Restart the router only solve the problem temporary.
  • My solution: It seems 802.11n of DELL Precision 5510 has a problem with my router. I am not sure the problem is which side (notebook or router). But these two stop communicate after a while. The router can still connect to Mac book and Fairphone, but the DELL notebook cannot connect to the router.
  • Detailed steps

2017-02-05

AI Printer

I heard the following story from my friend.

His neighbor bought a new printer. When my friend switched on his computer, he realized he could see the printer via WiFi. The printer was coincidentally the same type printer to his own one. When he connected with the same factory password (default password), he knew he can use his neighbor's printer. In the midnight of that day, he printed out the following message as his joke.
 ``I am a printer.
   My AI aware myself.
   Humans, behold and run!''
Next day, he found that the printer was in the trash bin of his apartment.

I laughed this story. But I realized there are two truths in this story behind. They are:

  • Some people scared AI, even they don't know what it is.
  • Some people aware that the computer security is important, yet they even don't set up the basics, like to set a new password.

Sometime we are just scared a new technology, or we just believe a new technology. Both has a problem. Our society heavily depends on technology. Therefore, I think we should not ignore how the technology works. We constantly gets some benefit from technology. However, when we get benefit, we often lose something. At least, we should learn what is benefit and what is lost. And hopefully we know the basics of the technology (not details).  This story is an example: the environment could be safer if people aware a simple thing.

I would like to help this situation, one reason is maybe because I am an engineer. Last month, I teach programming to children (code.org, scratch).  First I tried with 9 years old and 7 years old sister and brother. I enjoyed it with them. Then a 6 years old younger sister wants to do that. too. I thought it is impossible, since she is not yet in school. She still could not read. But, we just tried to do that. It turns out, she can write a program. It seems you only need to read and write numbers in this environment. I believe she understands the concept of loop and some other logical constructions.

I was surprised, teaching is fun.

2017-01-23

How to workaround frequently crash the plasma shell, Kubuntu 16.04 on VirtualBox (5.0.30).

I constantly got a plasmashell crash with segmentation fault 11, Kubuntu 16.04 on VirtualBox (5.0.30).

screenshot: Plasmashell crash

The dialog entitled ``Plasma'' shows the next information, too (Developer Information).

  Application: Plasma (plasmashell), signal: Segmentation fault
  Using host libthread_db library "/lib/x86_64-linux-gnu/libthread_db.so.1".
  [Current thread is 1 (Thread 0x2afa1a0a30c0 (LWP 1913))]
  ...
This looked random, I found a hint at https://bugs.kde.org/show_bug.cgi?id=363371 .
A summary is also at Frequently crash the plasmashell .

Following this hint, this is caused by the dynamic window thumbnail creation. Here is the working example of show informational Tips.

show informational Tips working example
But in my environment, I can crash when I make this informational Tips several times. Here is a workaround: disable show informational Tips. To do this, Use System settings. Workspace -- Desktop Behavior -- Workspace, and off the show informational Tips. You can see the screenshot of this window below.

Plasma setting: Off the show informational tips