Introduction Internet - almost the most important mass media in our everyday life - is becoming more and more indispensable for message delivery, phone-call connection, news, weathers, campaigns and merchandise notification or enterprise affair arrangement, public or private cloud storage and so on. Today I'm gonna focus on the last…

# Benny

Benny is a semi-unprofessional photographer, graphic design lover, computer specialist, internet fancier, music & film enthusiast and yet still a childish university student.

## ‘Let's Encrypt’ SSL Renewal for Nginx by ‘certbot’ cmd with Webroot Plugin

Problem Statement Today I found my whole site is down for several hours due to the expiration of the ssl (Secure Sockets Layer) certificate issued by Let's Encrypt and thanks to the DNS (Domain Name System) and CDN (Content Delivery Network) service and more importantly, the Always Online™ function provided…

## Control of An iOS Device with Mouse and Keyboard on A Computer

Introduction Nowadays, thanks to VNC, it is already a mature solution using your smart device (i.e. a phone or a pad) for the local control of a computer with both connected to the same LAN, or remotely if to the internet. However this article is going to tackle the…

## An Ultimate Chinese High-School Maths Problem

Question Solve \[\sqrt[3]{a+\frac{a+1}{3}\cdot \sqrt{\frac{8a-1}{3}}}+\sqrt[3]{a-\frac{a+1}{3}\cdot \sqrt{\frac{8a-1}{3}}}\] Solution: From the question, we regulate \[\begin{align*} \frac{8a-1}{3}&\geq 0\\ a&\geq \frac{1}{8} \end{align*}\] Let \[\xi…

## An Interesting High-School Maths Problem

Question Given \[f\left ( x \right )-\frac{1}{3}f\left ( \frac{x}{3} \right )=x,\] find \(f\left ( x \right )\). Alternative solution: We derive the following equations, \[f\left ( x \right )-\frac{1}{3}f\left ( \frac{x}{3} \right )=x\] \[\frac{1}{3^{1}}f\left…