This is the second post of my data privacy series. You may want to also check out this post for an introduction to data privacy and differential privacy. 🙂 For convenient, let’s repeat the definition of differential privacy from the previous post. Definition: -Differential Privacy The query is -differentially private if and only if for…
I need to work on a data privacy project and so am spending some time to review some notes I wrote couple years ago. I guess it would be a great exercise to reorganize them into a post series. And this will be my first post of this series. 🙂 Introduction to data privacy From…
Let say if Alice would like to send a secret message to Bob, she may want to first encrypt the message before sending it. Modern cryptographic techniques all use some secret keys to encrypt and decrypt a message. For example, we may generate a random sequence with a predefined seed (the key) and take the…
A group $latex G$ in the context of math is a simple algebraic structure with a product operation $latex *$. Naturally, the operator won’t be of much use if the structure is not closed under the operation. Namely, we would like to have $latex a * b$ also in $latex G$ if both elements $latex…
Getting nostalgia and suddenly would like to play a round of old StarCraft. I have upgraded to 16.04 since last year and couldn’t set resolution to 640×480 from Displays setting. But simply using xrandr -s actually works: xrandr -s 640×480 I can then recalibrate the stylus with the usual Wacom Tablet setting. 🙂
Trained as an electrical engineer, I am most comfortable with Matlab in terms of serving my math need. However, for symbolic math problems, Matlab is not as intuitive as Mathematica (of course, we can still do it though. Check out “syms”). But I never get used to the syntax of Mathematica. And I found the…
I tried to install Ubuntu 18.04 to MSI GS43VR 7RE laptop. It is a laptop with GTX 1060 gpu. I kind of expected hiccups with installation. Actually, I couldn’t even get Ubuntu to start with plain installation. The culprit is NVidia driver as expected. Adding “nomodeset” to boot option fixed the problem. One may also…
My goal is trying to setup a git server along side with one of my existing sites. Say my site has a domain name example.com. I want to setup a git server at https://git.example.com. I chose Gogs as it is quite light-weight and it appears to be sufficient for me. For security purpose, I tried…
I lost my mariadb root password and the recovery process does not work after many tries. Since I was not actually using any databases on that machine. I decided to simply reinstall MySQL server. But just running sudo apt purge mysql* didn’t clean up everything. I still got configuration errors when I try to reinstall…
As title, the issue is “fixed” by adding  [arch=amd64,i386] just after deb on every deb line in /etc/apt/source.list as suggested here. However, note that some deb lines may be included under the folder /etc/apt/source.list.d. So don’t forget adding [arch=amd64,i386] to them also. Another fix mentioned here is to remove the arm64 architecture completely. sudo dpkg –force-architecture –remove-architecture arm64 It did…