∫ntegrabℓε ∂iﬀerentiαℓs · unorganised notes, code, and writings of random topics

Excel conventions

September 15, 2021 blog work

Excel is quite ubiquitous but not many people use it well. The finance industry use it a lot and there are some good practices created. The key to use Excel (or other spreadsheet) well is to remember that there are two layers in it, the formula and the result, and... [more]

Using neovim

September 13, 2021 blog system

Have been using neovim for a few years now and I don’t feel a thing! To remember what should be done in case of reinstallation from scratch, it is better to write down some tips and configuration. [more]

Time Management for System Administrators

Thomas A. Limoncelli / 2006

September 11, 2021 book

This is a book I read 15 years ago. It is still very insightful re-reading it today. Perhaps because of the examples are more relevant, I found the time management advices are more useful. The theme of this book is “do not trust your brain” and therefore, we should offload... [more]

Diskless Debian

August 7, 2021 blog system

This documents my attempt to create a diskless, PXE boot, NFS-supported Debian system. The device is an Intel NUC and it is served by OpenWRT routers. There are posts about PXE previously. But in summary, the workflow of such system is [more]

Hurst parameter and fractional Brownian motion

July 26, 2021 blog math code

I was introduced to the concept of self-similarity and long-range dependency of a time series from the seminal paper On the Self-Similar Nature of Ethernet Traffic by Leland et al (1995). The Hurst parameter or the Hurst exponent is the key behind all these. [more]